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Takuji Ishikawa

Section

Graduate School of Biomedical Engineering

Job title

Professor

Degree

博士（工学）（東京工業大学）
修士（工学）（東京工業大学）

researchmap

https://researchmap.jp/read0210519

J-GLOBAL ID

200901093022229849

Education 2

Tokyo Institute of Technology　Graduate School, Division of Engineering

- 1999/03
Tokyo Institute of Technology

- 1994/03

Committee Memberships 46

日本機械学会東北支部　庶務幹事

2024/04 - Present
Asian-Pacific Association for Biomechanics　Treasure

2022/04 - Present
日本国際学生技術研修協会（IAESTE JAPAN）　理事

2022/04 - Present
Asian-Pacific Association for Biomechanics　Council Member

2021/12 - Present
日本機械学会バイオエンジニアリング部門　国際ジャーナル委員会委員長

2019/04 - Present
Journal of Biomechanical Science and Engineering　Editor in Chief

2019/04 - Present
日本学術会議連携会員

2018/04 - Present
World Congress of Biomechanics　Council Member

2014/07 - Present
日本機械学会バイオエンジニアリング部門　部門長

2024/04 - 2025/03
日本機械学会バイオエンジニアリング部門　幹事

2018/04 - 2020/03
BioMedical Engineering Online　Associate Editor

2016/10 - 2022/03
17th International Conference on BioMedical Engineering　Member of International Scientific Committee

2019/01 - 2019/12
日本機械学会東北支部　表彰幹事

2017/03 - 2019/03
日本機械学会バイオエンジニアリング部門第93期国際ジャーナル編集委員会　幹事

2016/04 - 2019/03
Journal of Biomechanical Science and Engineering　Chief Editor

2010/04 - 2019/03
Journal of Biomechanical Science and Engineering　Chief Editor

2010/04 - 2019/03
日本機械学会表彰部会　委員

2017/05 - 2018/03
日本機械学会表彰部会　委員

2017/05 - 2018/03
日本機械学会バイオエンジニアリング部門 2017年度計算力学部門運営委員会　委員

2017/04 - 2018/03
日本機械学会学術誌編集部会 2017年度英文ジャーナル編修委員会　幹事

2017/04 - 2018/03
日本機械学会バイオエンジニアリング部門 2017年度計算力学部門運営委員会　委員

2017/04 - 2018/03
日本機械学会学術誌編集部会 2017年度英文ジャーナル編修委員会　幹事

2017/04 - 2018/03
5th Switzerland-Japan Workshop on Biomechanixs (SJB 2017)　Scientific Committee

2017/02 - 2017/09
5th Switzerland-Japan Workshop on Biomechanixs (SJB 2017)　Scientific Committee

2017/02 - 2017/09
日本機械学会バイオエンジニアリング部門第93期国際ジャーナル編集委員会　幹事

2016/04 - 2017/03
日本機械学会バイオエンジニアリング部門 2016年度計算力学部門運営委員会　委員

2016/04 - 2017/03
日本機械学会バイオエンジニアリング部門 2016年度計算力学部門運営委員会　委員

2016/04 - 2017/03
The 8th Asian-Pacific Conference on Biomechanics　Local Committee member

2015/09 - 2017/03
日本機械学会バイオエンジニアリング部門国際委員会　委員長

2014/04 - 2016/03
日本機械学会流体工学部門運営委員会　運営委員

2014/04 - 2016/03
日本機械学会バイオエンジニアリング部門国際委員会　委員長

2014/04 - 2016/03
日本機械学会流体工学部門運営委員会　運営委員

2014/04 - 2016/03
日本機械学会バイオエンジニアリング部門企画委員会　委員

2013/04 - 2015/03
日本機械学会バイオエンジニアリング部門企画委員会　委員

2013/04 - 2015/03
日本機械学会バイオエンジニアリング部門運営委員会　運営委員

2010/04 - 2012/03
日本機械学会バイオエンジニアリング部門広報委員会　幹事

2010/04 - 2012/03
日本機械学会バイオエンジニアリング部門運営委員会　運営委員

2010/04 - 2012/03
日本機械学会バイオエンジニアリング部門広報委員会　幹事

2010/04 - 2012/03
Journal of Biomechanical Science and Engineering　Editor

2009/04 - 2010/03
Journal of Biomechanical Science and Engineering　Editor

2009/04 - 2010/03
日本機械学会バイオエンジニアリング部門運営委員会　運営委員

2007/04 - 2009/03
日本生体医工学会専門別研究会バイオメカニクス研究会　幹事

2007/04 - 2009/03
日本機械学会バイオエンジニアリング部門運営委員会　運営委員

2007/04 - 2009/03
日本生体医工学会専門別研究会バイオメカニクス研究会　幹事

2007/04 - 2009/03
Journal of Biomechanical Science and Engineering　Guest Editor

2007/04 - 2008/03
Journal of Biomechanical Science and Engineering　Guest Editor

2007/04 - 2008/03

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Professional Memberships 4

日本流体力学会
American Physical Society
エアロ・アクアバイオメカニズム学会
日本機械学会

Research Interests 3

Biophysics
Biomechanics
Biological Fluid Mechanics

Research Areas 1

Life sciences / Biomedical engineering /

Awards 15

Fellow of The American Physical Society

2024/06　The American Physical Society
業績賞

2023/06　日本機械学会バイオエンジニアリング部門
フェロー

2023/02　日本機械学会
流体科学研究賞

2022/11　一般財団法人機器研究会　遊泳微生物の流体力学および行動力学に関する研究
青葉工学振興会賞

2011/12　青葉工学振興会
みやぎ産業科学振興基金研究奨励賞

2010/05　みやぎ産業科学振興基金
科学技術分野の文部科学大臣表彰若手科学者賞

2010/04　文部科学大臣
日本機械学会バイオエンジニアリング部門瀬口賞

2007/01/07　日本機械学会
日本機械学会教育賞

2003/04/01　日本機械学会　子どもの科学技術および理科離れ解消のための公開講座と出前講座（「賢い主婦への出発」と「機械工学大好き講座」）
日本機械学会奨励賞

1999/04/01　日本機械学会　動脈狭窄部を通る血流の研究
JBSE Papers of the year award

2019/04　Journal of Biomechanical Science and Engineering　Elastohydrodynamic phase-lock in two rotating cilia
可視化情報学会アートコンテスト金賞

2015/07/01　可視化情報学会
JBSE Graphics of the year award

2013/03/30　JSME Bioengineering Division
JBSE Papers of the year award

2011/11/01　JSME Bioengineering Division
日本工学教育協会論文・論説賞

2010/08　日本工学教育協会

Show all ︎Show 5

Papers 553

Physics of microbial taxis and behaviours in response to various physical stimuli Invited Peer-reviewed

Takuji Ishikawa, Katsuhiko Sato, Toshihiro Omori, Kenjiro Yoshimura

Philosophical Transactions of the Royal Society A　383　20240264　2025/09
Transport phenomena in microswimmer suspensions: migration, collective motion, diffusion and rheology Invited Peer-reviewed

Takuji Ishikawa

Journal of Fluid Mechanics　1016　P1　2025/08/08

DOI： 10.1017/jfm.2025.10388 　
Ciliary fluid dynamics of swimming, feeding, pumping, and sensing Invited Peer-reviewed

Toshihiro Omori, Takuji Ishikawa

Physical Review Fluids　10　080501　2025/08/07
Publisher: American Physical Society (APS)
DOI： 10.1103/tj41-z3qq 　

eISSN： 2469-990X
Hydrodynamic confinement of bacteria within intestinal folds Peer-reviewed

Jinyou Yang, Toshihiro Omori, Kenji Kikuchi, Takuji Ishikawa

Proceedings of the Royal Society B　292　20243068　2025/05

DOI： 10.6084/m9.figshare.c.7738869 　
The architecture of sponge choanocyte chambers is well adapted to mechanical pumping functions Peer-reviewed

Takumi Ogawa, Shuji Koyama, Toshihiro Omori, Kenji Kikuchi, Hélène de Maleprade, Raymond E. Goldstein, Takuji Ishikawa

Proc. Natl. Acad. Sci. USA　122　(12)　2025/03/21
Publisher: Proceedings of the National Academy of Sciences
DOI： 10.1073/pnas.2421296122 　

ISSN： 0027-8424

eISSN： 1091-6490

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Sponges, the basalmost members of the animal kingdom, exhibit a range of complex architectures in which microfluidic channels connect multitudes of spherical chambers lined with choanocytes, flagellated filter-feeding cells. Choanocyte chambers can possess scores or even hundreds of such cells, which drive complex flows entering through porous walls and exiting into the sponge channels. One of the mysteries of the choanocyte chamber is its spherical shape, as it seems inappropriate for inducing directional transport since many choanocyte flagella beat in opposition to such a flow. Here, we combine direct imaging of choanocyte chambers in living sponges with computational studies of many-flagella models to understand the connection between chamber architecture and directional flow. We find that those flagella that beat against the flow play a key role in raising the pressure inside the choanocyte chamber, with the result that the flow rate and mechanical pumping efficiency reach a maximum at a small outlet opening angle. Comparison between experimental observations and the results of numerical simulations reveal that the chamber diameter, flagellar wave number, and the outlet opening angle of the freshwater sponge Ephydatia muelleri , as well as several other species, are related in a manner that maximizes the mechanical pumping functions. These results indicate the subtle balances at play during morphogenesis of choanocyte chambers, and give insights into the physiology and body design of sponges.
Swirling Instability Mediated by Elastic and Hydrodynamic Couplings in Cytoplasmic Streaming Peer-reviewed

Takuji Ishikawa, Takayuki Torisawa, Hirofumi Wada, Akatsuki Kimura

PRX Life　3　(1)　013008　2025/02/06
Publisher: American Physical Society (APS)
DOI： 10.1103/prxlife.3.013008 　

eISSN： 2835-8279

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Cytoplasmic streaming is driven by molecular motors that move along the cytoskeleton and entrain the surrounding fluid. In certain cell types, the direction of cytoplasmic streaming is not predefined but rather stochastic. For example, in meiotic cytoplasmic streaming of zygotes, the direction of the swirl reverses over time [Kimura , ]. While a mean-field theory explained the reversal, the structure of flows in three-dimensional space and the mechanical role of the endoplasmic reticulum (ER) remains unknown. To test the hypothesis that the elastic ER bonds and hydrodynamic interactions between microtubules mediate the orientational order of microtubules, leading to directional cytoplasmic streaming, we computationally investigated fluid-structure interactions in cytoplasmic flow, ER networks, and microtubule structures in the presence of microtubule dynamic instability. The results indicate that the occasionally reversing swirls emerge within a certain range of ER elasticity, and our experimental measurements of the ER elasticity agree with the numerical predictions. Mass transport analysis further demonstrates that the reversing swirls are suitable for intracellular particle mixing. These findings illustrate the delicate balance of meiotic cytoplasmic streaming and provide insights into the physiology of the embryogenesis. Published by the American Physical Society 2025
Fluid dynamics of squirmers and ciliated microorganisms Invited Peer-reviewed

Takuji Ishikawa

Annual Review of Fluid Mechanics　56　95-121　2024/01
Swimming, Feeding and Inversion of Multicellular Choanoflagellate Sheets Peer-reviewed

Lloyd Fung, Adam Konkol, Takuji Ishikawa, Ben T. Larson, Thibaut Brune, Raymo, E. Goldstein

Physical Review Letters　131　168401　2023/10
Immotile cilia mechanically sense the direction of fluid flow for left-right determination Peer-reviewed

Takanobu A. Katoh, Toshihiro Omori, Katsutoshi Mizuno, Xiaorei Sai, Katsura Minegishi, Yayoi Ikawa, Hiromi Nishimura, Takeshi Itabashi, Eriko Kajikawa, Sylvain Hiver, Atsuko H. Iwane, Takuji Ishikawa, Yasushi Okada, Takayuki Nishizaka, Hiroshi Hamada

Science　379　(6627)　66-71　2023/01/06
Publisher: American Association for the Advancement of Science (AAAS)
DOI： 10.1126/science.abq8148 　

ISSN： 0036-8075

eISSN： 1095-9203

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Immotile cilia at the ventral node of mouse embryos are required for sensing leftward fluid flow that breaks left-right symmetry of the body. However, the flow-sensing mechanism has long remained elusive. In this work, we show that immotile cilia at the node undergo asymmetric deformation along the dorsoventral axis in response to the flow. Application of mechanical stimuli to immotile cilia by optical tweezers induced calcium ion transients and degradation of Dand5 messenger RNA (mRNA) in the targeted cells. The Pkd2 channel protein was preferentially localized to the dorsal side of immotile cilia, and calcium ion transients were preferentially induced by mechanical stimuli directed toward the ventral side. Our results uncover the biophysical mechanism by which immotile cilia at the node sense the direction of fluid flow.
Near-wall rheotaxis of the ciliate Tetrahymena induced by the kinesthetic sensing of cilia Peer-reviewed

Takuya Ohmura, Yukinori Nishigami, Atsushi Taniguchi, Shigenori Nonaka, Takuji Ishikawa, Masatoshi Ichikawa

Science Advances　7　(43)　2021/10/22
Publisher: American Association for the Advancement of Science (AAAS)
DOI： 10.1126/sciadv.abi5878 　

eISSN： 2375-2548

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Kinesthetic sensing of cilia results in upstream motility for Tetrahymena pyriformis , a typical freshwater microorganism.
Swimming microorganisms acquire optimal efficiency with multiple cilia Peer-reviewed

Toshihiro Omori, Hiroaki Ito, Takuji Ishikawa

Proc. Natl. Acad. Sci. USA　117　30201-30207　2020/12
Biomechanics of Tetrahymena escaping from a dead end Peer-reviewed

Takuji Ishikawa, Kenji Kikuchi

Proceedings of the Royal Society B　285　20172368　2018/02
Simple mechanosense and response of cilia motion reveal the intrinsic habits of ciliates Peer-reviewed

Ohmura, T., Nishigami, Y., Taniguchi, A., Nonaka, S., Manabe, J., Ishikawa, T., Ichikawa, M.

Proc. Natl. Acad. Sci. USA　115　(13)　3231-3236　2018

DOI： 10.1073/pnas.1718294115 　
Hydrodynamic Phase Locking in Mouse Node Cilia Peer-reviewed

Atsuko Takamatsu, Kyosuke Shinohara, Takuji Ishikawa, Hiroshi Hamada

PHYSICAL REVIEW LETTERS　110　(24)　248107　2013/06

DOI： 10.1103/PhysRevLett.110.248107 　

ISSN： 0031-9007
Reorientation of a Nonspherical Capsule in Creeping Shear Flow Peer-reviewed

Toshihiro Omori, Yohsuke Imai, Takami Yamaguchi, Takuji Ishikawa

PHYSICAL REVIEW LETTERS　108　(13)　138102　2012/03

DOI： 10.1103/PhysRevLett.108.138102 　

ISSN： 0031-9007
Energy Transport in a Concentrated Suspension of Bacteria Peer-reviewed

T. Ishikawa, N. Yoshida, H. Ueno, M. Wiedeman, Y. Imai, T. Yamaguchi

PHYSICAL REVIEW LETTERS　107　(2)　028102 (Editors’ Suggestions)　2011/07

DOI： 10.1103/PhysRevLett.107.028102 　

ISSN： 0031-9007
Dancing Volvox: Hydrodynamic Bound States of Swimming Algae Peer-reviewed

Knut Drescher, Kyriacos C. Leptos, Idan Tuval, Takuji Ishikawa, Timothy J. Pedley, Raymond E. Goldstein

PHYSICAL REVIEW LETTERS　102　(16)　168101 (cover)　2009/04

DOI： 10.1103/PhysRevLett.102.168101 　

ISSN： 0031-9007
Coherent structures in monolayers of swimming particles Peer-reviewed

Takuji Ishikawa, T. J. Pedley

PHYSICAL REVIEW LETTERS　100　(8)　088103　2008/02

DOI： 10.1103/PhysRevLett.100.088103 　

ISSN： 0031-9007
Swimming and mixing of an ellipsoidal squirmer in a viscoplastic fluid Peer-reviewed

Yan Xia, Zhaosheng Yu, Zhaowu Lin, Takuji Ishikawa

Journal of Fluid Mechanics　1015　2025/07/16
Publisher: Cambridge University Press (CUP)
DOI： 10.1017/jfm.2025.10329 　

ISSN： 0022-1120

eISSN： 1469-7645

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Viscoplastic fluids exhibit yield stress, beyond which they flow viscously, while at lower stress levels they behave as solids. Despite their fundamental biological and medical importance, the hydrodynamics of swimming in viscoplastic environments is still evolving. In this study, we investigate the swimming of an ellipsoidal squirmer and the associated tracer diffusion in a Bingham viscoplastic fluid. The results illustrate that neutral squirmers in viscoplastic fluids experience a reduction in swimming speed and an increase in power dissipation as the Bingham number increases, with swimming efficiency peaking at moderate Bingham numbers. As the aspect ratio of a squirmer increases, ellipsoidal squirmers exhibit significantly higher swimming speeds in viscoplastic fluids. The polar and swirling modes can either enhance or reduce swimming speed, depending on the specific scenarios. These outcomes are closely related to the confinement effects induced by the yield surface surrounding the swimmer, highlighting how both swimmer shape and swimming mode can significantly alter the yield surface and, in turn, modify the swimming hydrodynamics. In addition, this study investigates the influence of viscoplasticity on swimmer-induced diffusion in a dilute suspension. The plasticity enforces the velocity far from the swimmer to be zero, thus breaking the assumptions used in Newtonian fluids. The diffusivity reaches its maximum at intermediate aspect ratios and Bingham numbers, and increases with the magnitude of the squirmer’s dipolarity. These findings are important to understand microscale swimming in viscoplastic environments and the suspension properties.
Capsule damage by an enclosed microswimmer Peer-reviewed

Zhihan Huang, Toshihiro Omori, Takuji Ishikawa

Journal of Fluid Mechanics　1013　A12　2025/06/13
Publisher: Cambridge University Press (CUP)
DOI： 10.1017/jfm.2025.10238 　

ISSN： 0022-1120

eISSN： 1469-7645

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Capsules are widely used in bioengineering, chemical engineering and industry. The development of drug delivery systems using deformable capsules is progressing, yet the regulation of drug release within a capsule remains a challenge. Meanwhile, a microswimmer enclosed in a capsule can generate a large lubrication force on the capsule membrane, which could result in deformation and mechanical damage to the membrane. In this study, we numerically investigate how a capsule can be damaged by an enclosed microswimmer. The capsule membrane is modelled as a two-dimensional neo-Hookean material, with its deformability parametrised by capillary number. An isotropic brittle damage model is applied to express membrane rupture, with the Lighthill–Blake squirmer serving as the microswimmer model. In a sufficiently small capillary number regime, pusher-type squirmers exhibit stable swimming along the capsule membrane, while neutral-type and puller-type squirmers exhibit swimming towards the membrane and remain stationary. As capillary number increases, the damage to the membrane increases and rupture occurs in all swimming modes. For pusher-type squirmers, the critical capillary number leading to rupture is dependent on the initial incidence angle, whereas neutral-type and puller-type squirmers are independent of the initial value. Furthermore, we present methods for controlling membrane damage by magnetically orienting the microswimmer. The findings reveal that a static magnetic field can orient the microswimmer, leading to membrane damage and rupture even for a capsule that cannot be damaged by free swimming, while controlling the swimming path with a rotating magnetic field enables soft membranes to maintain deformation without rupture.
Microstructure and deformation in suspensions of soft microswimmers Peer-reviewed

Kiyoto Kubo, Toshihiro Omori, Takuji Ishikawa

Journal of Fluid Mechanics　1011　A31　2025/06
Self-organization of spermatozoa via unsteady elastohydrodynamic interactions enhances their swimming speed and efficiency Peer-reviewed

Nanami Taketoshi, Toshihiro Omori, Takuji Ishikawa

Physical Review E　111　(3)　2025/03/18
Publisher: American Physical Society (APS)
DOI： 10.1103/physreve.111.035103 　

ISSN： 2470-0045

eISSN： 2470-0053
Helical swimming motion driven by coordinated rotation of flagellar apparatus in marine bacterial cells

Yuji SHIMOGONYA, Juanfang RUAN, Takayuki KATO, Takuji ISHIKAWA,, Keiichi NAMBA, Long-Fei WU, Masayoshi NISHIYAMA

Journal of Biomechanical Science and Engineering　20　(1)　24-00284　2025/01
Publisher: Japan Society of Mechanical Engineers
DOI： 10.1299/jbse.24-00284 　

eISSN： 1880-9863
Surface-active microrobots can propel through blood faster than inert microrobots Peer-reviewed

Chenjun Wu, Toshihiro Omori, Takuji Ishikawa

PNAS Nexus　3　(10)　2024/10/01
Publisher: Oxford University Press (OUP)
DOI： 10.1093/pnasnexus/pgae463 　

eISSN： 2752-6542

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Abstract Microrobots that can move through a network of blood vessels have promising medical applications. Blood contains a high volume fraction of blood cells, so in order for a microrobot to move through the blood, it must propel itself by rearranging the surrounding blood cells. However, swimming form effective for propulsion in blood is unknown. This study shows numerically that a surface-active microrobot, such as a squirmer, is more efficient in moving through blood than an inert microrobot. This is because the surface velocity of the microrobot steers the blood cells laterally, allowing them to propel themselves into the hole they are digging. When the microrobot size is comparable to a red blood cell or when the microrobot operates under a low Capillary number, the puller microrobot swims faster than the pusher microrobot. The trend reverses under considerably smaller microrobot sizes or high Capillary number scenarios. Additionally, the swimming speed is strongly dependent on the hematocrit and magnetic torque used to control the microrobot orientation. A comparative analysis between the squirmer and Janus squirmer models underscores the extensive applicability of the squirmer model. The obtained results provide new insight into the design of microrobots propelled efficiently through blood, paving the way for innovative medical applications.
Drag force on a microrobot propelled through blood Peer-reviewed

Chenjun Wu, Toshihiro Omori, Takuji Ishikawa

Communications Physics　7　(1)　2024/07/13
Publisher: Springer Science and Business Media LLC
DOI： 10.1038/s42005-024-01724-4 　

eISSN： 2399-3650

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Abstract Controlling microrobot locomotion in vessels and capillaries is crucial for precise drug delivery and minimally invasive surgeries. However, this is challenging due to the complex interactions with red blood cells (RBCs) and the difficulty navigating within the dense environment. Here, we construct a numerical framework to evaluate the relative resistance coefficient ($${C}_{ { { { { { { { \rm{r } } } } } } } } }^{* }$$) of a microrobot propelled through RBC suspensions. Our experiments validate the numerical results. We find that $${C}_{ { { { { { { { \rm{r } } } } } } } } }^{* }$$ increases for smaller microrobots and higher hematocrit levels, while magnetic force strength weakly impacts $${C}_{ { { { { { { { \rm{r } } } } } } } } }^{* }$$. $${C}_{ { { { { { { { \rm{r } } } } } } } } }^{* }$$ is smaller than the resistance coefficient of a macroscale robot estimated from the apparent viscosity of the RBC suspension. The aspect ratio of a prolate ellipsoidal microrobot influences $${C}_{ { { { { { { { \rm{r } } } } } } } } }^{* }$$ along its long-axis direction. Additionally, machine learning accurately predicts $${C}_{ { { { { { { { \rm{r } } } } } } } } }^{* }$$. These insights could enhance the design and control of microrobots for medical applications.
気管チューブによるベンチュリー効果が、ペンデルフト現象に与える影響 secondary publication(abridged translation) Peer-reviewed

高橋和博, 外山裕章, 江島豊, Yang Jinyou, 菊地謙次, 石川拓司, 山内正憲

呼吸療法　41　(1)　107-115　2024/05
Publisher: (一社)日本呼吸療法医学会
eISSN： 2759-4289
Bacterial accumulation in intestinal folds induced by physical and biological factors. International-journal

Jinyou Yang, Toma Isaka, Kenji Kikuchi, Keiko Numayama-Tsuruta, Takuji Ishikawa

BMC biology　22　(1)　76-76　2024/04/05

DOI： 10.1186/s12915-024-01874-5 　

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BACKGROUND: The gut microbiota, vital for host health, influences metabolism, immune function, and development. Understanding the dynamic processes of bacterial accumulation within the gut is crucial, as it is closely related to immune responses, antibiotic resistance, and colorectal cancer. We investigated Escherichia coli behavior and distribution in zebrafish larval intestines, focusing on the gut microenvironment. RESULTS: We discovered that E. coli spread was considerably suppressed within the intestinal folds, leading to a strong physical accumulation in the folds. Moreover, a higher concentration of E. coli on the dorsal side than on the ventral side was observed. Our in vitro microfluidic experiments and theoretical analysis revealed that the overall distribution of E. coli in the intestines was established by a combination of physical factor and bacterial taxis. CONCLUSIONS: Our findings provide valuable insight into how the intestinal microenvironment affects bacterial motility and accumulation, enhancing our understanding of the behavioral and ecological dynamics of the intestinal microbiota.
Glucose stockpile in the intestinal apical brush border in C. elegans

Takumi Saito, Kenji Kikuchi, Takuji Ishikawa

Biochemical and Biophysical Research Communications　706　2024/04

DOI： 10.1016/j.bbrc.2024.149762 　

ISSN： 0006-291X

eISSN： 1090-2104
High shear flow prevents bundling of bacterial flagella and induces lateral migration away from a wall Peer-reviewed

Jinyou Yang, Kenji Kikuchi, Takuji Ishikawa

Communications Physics　6　354　2023/11
50-year History and Perspective on Biomechanics of Swimming Microorganisms: Part II. Collective Behaviours Invited Peer-reviewed

Journal of Biomechanics　160　111802　2023/09
Computational Fluid Dynamics of Swimming Microorganisms Invited Peer-reviewed

Toshihiro Omori, Takuji Ishikawa

Journal of the Physical Society of Japan　92　121002　2023/09
50-year History and perspective on biomechanics of swimming microorganisms: Part I. Individual behaviours Invited Peer-reviewed

Takuji Ishikawa, T.J. Pedley

Journal of Biomechanics　158　111706-111706　2023/09
Publisher: Elsevier BV
DOI： 10.1016/j.jbiomech.2023.111706 　

ISSN： 0021-9290
Endotracheal tube, by the venturi effect, reduces the efficacy of increasing inlet pressure in improving pendelluft International-journal Peer-reviewed

Kazuhiro Takahashi, Hiroaki Toyama, Yutaka Ejima, Jinyou Yang, Kenji Kikuchi, Takuji Ishikawa, Masanori Yamauchi

PLOS ONE　18　e0291319　2023/09

DOI： 10.1371/journal.pone.0291319 　

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In mechanically ventilated severe acute respiratory distress syndrome patients, spontaneous inspiratory effort generates more negative pressure in the dorsal lung than in the ventral lung. The airflow caused by this pressure difference is called pendelluft, which is a possible mechanisms of patient self-inflicted lung injury. This study aimed to use computer simulation to understand how the endotracheal tube and insufficient ventilatory support contribute to pendelluft. We established two models. In the invasive model, an endotracheal tube was connected to the tracheobronchial tree with 34 outlets grouped into six locations: the right and left upper, lower, and middle lobes. In the non-invasive model, the upper airway, including the glottis, was connected to the tracheobronchial tree. To recreate the inspiratory effort of acute respiratory distress syndrome patients, the lower lobe pressure was set at -13 cmH2O, while the upper and middle lobe pressure was set at -6.4 cmH2O. The inlet pressure was set from 10 to 30 cmH2O to recreate ventilatory support. Using the finite volume method, the total flow rates through each model and toward each lobe were calculated. The invasive model had half the total flow rate of the non-invasive model (1.92 L/s versus 3.73 L/s under 10 cmH2O, respectively). More pendelluft (gas flow into the model from the outlets) was observed in the invasive model than in the non-invasive model. The inlet pressure increase from 10 to 30 cmH2O decreased pendelluft by 11% and 29% in the invasive and non-invasive models, respectively. In the invasive model, a faster jet flowed from the tip of the endotracheal tube toward the lower lobes, consequently entraining gas from the upper and middle lobes. Increasing ventilatory support intensifies the jet from the endotracheal tube, causing a venturi effect at the bifurcation in the tracheobronchial tree. Clinically acceptable ventilatory support cannot completely prevent pendelluft.
Flow-induced diffusion in a packed lattice of squirmers Peer-reviewed

Yu Kogure, Toshihiro Omori, Takuji Ishikawa

Journal of Fluid Mechanics　971　A17-1　2023/09
Biophysical Analysis of Mechanical Signals in Immotile Cilia of Mouse Embryonic Nodes Using Advanced Microscopic Techniques Peer-reviewed

Takanobu Katoh, Toshihiro Omori, Takuji Ishikawa, Yasushi Okada, Hiroshi Hamada

BIO-PROTOCOL　13　(14)　2023/07/20
Publisher: Bio-Protocol, LLC
DOI： 10.21769/bioprotoc.4715 　

ISSN： 2331-8325
Effectiveness of substantial shortening of the endotracheal tube for decreasing airway resistance and increasing tidal volume during pressure-controlled ventilation in pediatric patients: a prospective observational study. International-journal Peer-reviewed

Kazuhiro Takahashi, Hiroaki Toyama, Ryosuke Kubo, Norifumi Yoshida, Yutaka Ejima, Kenji Kikuchi, Takuji Ishikawa, Masanori Yamauchi

Journal of clinical monitoring and computing　37　1513-1519　2023/06/08

DOI： 10.1007/s10877-023-01038-w 　

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The endotracheal tubes (ETTs) used for children have a smaller inner diameter. Accordingly, the resistance across ETT (RETT) is higher. Theoretically, shortening the ETTs can decrease total airway resistance (Rtotal), because Rtotal is sum of RETT and patient's airway resistance. However, the effectiveness of ETT shortening for mechanical ventilation in the clinical setting has not been reported. We assessed the effectiveness of shortening a cuffed ETT for decreasing Rtotal, and increasing tidal volume (TV), and estimated the RETT/Rtotal ratio in children. In anesthetized children in a constant pressure-controlled ventilation setting, Rtotal and TV were measured with a pneumotachometer before and after shortening a cuffed ETT. In a laboratory experiment, the pressure gradient across the original length, shortened length, and the slip joint alone of the ETT were measured. We then determined the RETT/Rtotal ratio using the above results. The clinical study included 22 children. The median ETT percent shortening was 21.7%. Median Rtotal was decreased from 26 to 24 cmH2O/L/s, and median TV was increased by 6% after ETT shortening. The laboratory experiment showed that ETT length and the pressure gradient across ETT are linearly related under a certain flow rate, and approximately 40% of the pressure gradient across the ETT at its original length was generated by the slip joint. Median RETT/Rtotal ratio were calculated as 0.69. The effectiveness of ETT shortening on Rtotal and TV was very limited, because the resistance of the slip joint was very large.
Reciprocating intestinal flows enhance glucose uptake in C. elegans. International-journal Peer-reviewed

Yuki Suzuki, Kenji Kikuchi, Keiko Numayama-Tsuruta, Takuji Ishikawa

Scientific reports　12　(1)　15310-15310　2022/09/21

DOI： 10.1038/s41598-022-18968-1 　

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Despite its physiological and pathological importance, the mechanical relationship between glucose uptake in the intestine and intestinal flows is unclear. In the intestine of the nematode Caenorhabditis elegans, the defecation motor program (DMP) causes reciprocating intestinal flows. Although the DMP is frequently activated in the intestines, its physiological function is unknown. We evaluated the mechanical signature of enhanced glucose uptake by the DMP in worms. Glucose uptake tended to increase with increasing flow velocity during the DMP because of mechanical mixing and transport. However, the increase in input energy required for the DMP was low compared with the calorie intake. The findings suggest that animals with gastrointestinal motility exploit the reciprocating intestinal flows caused by peristalsis to promote nutrient absorption by intestinal cells.
Instability of an active fluid jet Peer-reviewed

Takuji Ishikawa, Thanh-Nghi Dang, Eric Lauga

Physical Review Fluids　7　(9)　2022/09/13
Publisher: American Physical Society (APS)
DOI： 10.1103/physrevfluids.7.093102 　

eISSN： 2469-990X
Self-sustaining oscillation of two axonemal microtubules based on a stochastic bonding model between microtubules and dynein Peer-reviewed

T. Omori, S. Munakata, T. Ishikawa

Physical Review E　106　(1)　2022/07/07
Publisher: American Physical Society (APS)
DOI： 10.1103/physreve.106.014402 　

ISSN： 2470-0045

eISSN： 2470-0053
Soft Microswimmer Powered by Fluid Oscillation Peer-reviewed

Takuji Ishikawa, Takeru Morita, Toshihiro Omori

Journal of Robotics and Mechatronics　34　(2)　298-300　2022/04/20
Publisher: Fuji Technology Press Ltd.
DOI： 10.20965/jrm.2022.p0298 　

ISSN： 0915-3942

eISSN： 1883-8049

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In this letter, we review the results of our recent studies on a soft microswimmer powered by fluid oscillations. The microswimmer consists of an elastic membrane with a prolate spheroidal reference shape containing a rigid sphere. The swimming direction can be controlled by appropriately applying fluid oscillations. The obtained knowledge will be useful for future artificial microswimmer designs.
Immotile cilia of the mouse node sense a fluid flow–induced mechanical force for left-right symmetry breaking

Takanobu A. Katoh, Toshihiro Omori, Katsutoshi Mizuno, Xiaorei Sai, Katsura Minegishi, Yayoi Ikawa, Hiromi Nishimura, Takeshi Itabashi, Eriko Kajikawa, Sylvain Hiver, Atsuko H. Iwane, Takuji Ishikawa, Yasushi Okada, Takayuki Nishizaka, Hiroshi Hamada

2022/04/12
Publisher: Cold Spring Harbor Laboratory
DOI： 10.1101/2022.04.11.487968 　

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Immotile cilia of crown cells at the node of mouse embryos are required for sensing of a leftward fluid flow¹ that gives rise to the breaking of left-right (L-R) symmetry². The flow-sensing mechanism has long remained elusive, however, with both mechanosensing and chemosensing models having been proposed^{1, 3–5}. Here we show that immotile cilia at the mouse node respond to mechanical force. In the presence of a leftward flow, immotile cilia on the left side of the node bend toward the ventral side whereas those on the right side bend toward the dorsal side. Application of mechanical stimuli to immotile cilia along the dorsoventral axis by optical tweezers induced Ca²⁺ transients and degradation of Dand5 mRNA—the first known L-R asymmetric molecular events—in the targeted cells. The Pkd2 channel protein was found to be preferentially localized to the dorsal side of immotile cilia on both left and right sides of the node, and the observed induction of Ca²⁺ transients preferentially by mechanical stimuli directed toward the ventral side could explain the differential response of immotile cilia to the directional flow. Our results thus suggest that immotile cilia at the node sense the direction of fluid flow in a manner dependent on a flow-generated mechanical force.
Lubrication theory and boundary element hybrid method for calculating hydrodynamic forces between particles in near contact Peer-reviewed

Takuji Ishikawa

Journal of Computational Physics　452　110913-110913　2022/03
Publisher: Elsevier BV
DOI： 10.1016/j.jcp.2021.110913 　

ISSN： 0021-9991
Pairwise scattering and bound states of spherical microorganisms Peer-reviewed

C. Darveniza, T. Ishikawa, T. J. Pedley, D. R. Brumley

Physical Review Fluids　7　(1)　2022/01/31
Publisher: American Physical Society (APS)
DOI： 10.1103/physrevfluids.7.013104 　

eISSN： 2469-990X
Rheotaxis and migration of an unsteady microswimmer Peer-reviewed

T. Omori, K. Kikuchi, M. Schmitz, M. Pavlovic, C.-H. Chuang, T. Ishikawa

Journal of Fluid Mechanics　930　2022/01/10
Publisher: Cambridge University Press (CUP)
DOI： 10.1017/jfm.2021.921 　

ISSN： 0022-1120

eISSN： 1469-7645

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Rheotaxis and migration of cells in a flow field have been investigated intensively owing to their importance in biology, physiology and engineering. In this study, first, we report our experiments showing that the microalgae Chlamydomonas can orient against the channel flow and migrate to the channel centre. Second, by performing boundary element simulations, we demonstrate that the mechanism of the observed rheotaxis and migration has a physical origin. Last, using a simple analytical model, we reveal the novel physical mechanisms of rheotaxis and migration, specifically the interplay between cyclic body deformation and cyclic swimming velocity in the channel flow. The discovered mechanism can be as important as phototaxis and gravitaxis, and likely plays a role in the movement of other natural microswimmers and artificial microrobots with non-reciprocal body deformation.
Influence of Respiratory Gas Density on Tidal Volume During Pressure-Controlled Ventilation: A Laboratory Investigation and Observational Study in Children.

Kazuhiro Takahashi, Hiroaki Toyama, Yutaro Funahashi, Shin Kawana, Yutaka Ejima, Kenji Kikuchi, Takuji Ishikawa, Masanori Yamauchi

The Tohoku journal of experimental medicine　256　(4)　271-281　2022

DOI： 10.21203/rs.3.rs-711979/v1 　

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Fluid mechanics show that high-density gases need more energy while flowing through a tube. Thus, high-density anesthetic gases consume more energy to flow and less energy for lung inflation during general anesthesia. However, its impact has not been studied. Therefore, this study aimed to investigate the effects of high-density anesthetic gases on tidal volume in laboratory and clinical settings. In the laboratory study, a test lung was ventilated at the same pressure-controlled ventilation with 22 different gas compositions (density range, 1.22-2.27 kg/m3) using an anesthesia machine. A pneumotachometer was used to record the tidal volume of the test lung and the respiratory gas composition; it showed that the tidal volume of the test lung decreased as the respiratory gas density increased. In the clinical study, the change in tidal volume per body weight, accompanied by gas composition change (2% sevoflurane in oxygen and with 0-30-60% of N2O), was recorded in 30 pediatric patients. The median tidal volume per body weight decreased by 10% when the respiratory gas density increased from 1.41 kg/m3 to 1.70 kg/m3, indicating a significant between-group difference (P < 0.0001). In both settings, an increase in respiratory gas density decreased the tidal volume during pressure-controlled ventilation, which could be explained by the fluid dynamics theory. This study clarified the detailed mechanism of high-density anesthetic gas reduced the tidal volume during mechanical ventilation and revealed that this phenomenon occurs during pediatric anesthesia, which facilitates further understanding of the mechanics of ventilation during anesthesia practice and respiratory physiology.
Microbial Brazil nut effect. International-journal Peer-reviewed

Atul Srivastava, Kenji Kikuchi, Takuji Ishikawa

Soft matter　17　(46)　10428-10436　2021/12/01

DOI： 10.1039/d1sm01327k 　

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The Brazil nut effect (BNE) is a counter-intuitive process of segregation of a large object inside a vibrated granular medium (GM), which has been studied widely by subjecting GMs to various kinds of shears and vibrations. In this article, we report a new kind of BNE which occurs as a consequence of granular fluctuations induced by microbe-generated gas bubbles. We call it the 'microbial Brazil nut effect'. The paper demonstrates microbial BNE for a bidisperse granular mixture as well as for intruder segregation. Furthermore, using X-ray μCT and a simple scaling argument for segregation velocity, the paper clarifies the transport mechanics of an intruder inside a bubbly granular bed. We think the reported phenomenon should be ubiquitous in the microbe-populated wet sandy floors of waterbodies and may have some implication on the distribution of material near the floors.
工学的アプローチによるモデル生物の流動の医学・生物学的理解

菊地謙次, 石川拓司

細胞　53　(13)　858-863　2021/11
Publisher: (株)ニュー・サイエンス社
ISSN： 1346-7557
Impact of rheological properties on bacterial streamer formation Peer-reviewed

Hiroki Kitamura, Toshihiro Omori, Takuji Ishikawa

Journal of The Royal Society Interface　18　(183)　2021/10/20
Publisher: The Royal Society
DOI： 10.1098/rsif.2021.0546 　

eISSN： 1742-5662

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Bacterial biofilms, which can be found wherever there is water and a substrate, can cause chronic infections and clogging of industrial flow systems. Despite intensive investigation of the dynamics and rheological properties of biofilms, the impact of their rheological properties on streamer growth remains unknown. We numerically simulated biofilm growth in a pillar-flow and investigated the effects of rheological properties of a filamentous flow-shaped biofilm, called a ‘streamer’, on its formation by varying the viscoelasticity. The flow-field is assumed to be a Stokes flow and is solved by a boundary element method. A Maxwell model is used for extracellular matrix-mediated streamer growth to express the fluidity of streamer formations. Both high elastic modulus and viscosity are needed for streamer formation, and high viscosity promotes streamer growth at low cell concentrations. Our findings are consistent with experimental observations and can explain the relationship between the cell concentrations and viscosity at which streamers form.
Non-biodegradable objects may boost microbial growth in water bodies by harnessing bubbles Peer-reviewed

Atul Srivastava, Kenji Kikuchi, Takuji Ishikawa

Royal Society Open Science　8　(9)　210646-210646　2021/09/15
Publisher: The Royal Society
DOI： 10.1098/rsos.210646 　

eISSN： 2054-5703

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Given the ubiquity of bubbles and non-biodegradable wastes in aqueous environments, their transport through bubbles should be widely extant in water bodies. In this study, we investigate the effect of bubble-induced waste transport on microbial growth by using yeasts as model microbes and a silicone rubber object as model waste. Noteworthily, this object repeatedly rises and sinks in fluid through fluctuations in bubble-acquired buoyant forces produced by cyclic nucleation, growth and release of bubbles from object's surface. The rise–sink movement of the object gives rise to a strong bulk mixing and an enhanced resuspension of cells from the floor. Such spatially dynamic contaminant inside a nutrient-rich medium also leads to an increment in the total microbe concentration in the fluid. The enhanced concentration is caused by strong nutrient mixing generated by the object's movement which increases the nutrient supply to growing microbes and thereby, prolonging their growth phases. We confirm these findings through a theoretical model for cell concentration and nutrient distribution in fluid medium. The model is based on the continuum hypothesis and it uses the general conservation law which takes an advection–diffusion growth form. We conclude the study with the demonstration of bubble-induced digging of objects from model sand.
Rheology of a concentrated suspension of spherical squirmers: monolayer in simple shear flow Peer-reviewed

Takuji Ishikawa, D. R. Brumley, T. J. Pedley

Journal of Fluid Mechanics　914　A26　2021/03
Zigzag instability of biased pusher swimmers Peer-reviewed

Eric Lauga, Thanh Nghi Dang, Takuji Ishikawa

EPL　133　44002　2021/02
Cilia and centrosomes: Ultrastructural and mechanical perspectives Invited Peer-reviewed

Takuji Ishikawa, Hironori Ueno, Toshihiro Omori, Kenji Kikuchi

Seminars in Cell & Developmental Biology　110　61-69　2021/02
Publisher: Elsevier BV
DOI： 10.1016/j.semcdb.2020.03.007 　

ISSN： 1084-9521
The bubble induced population dynamics of fermenting yeasts Peer-reviewed

Atul Srivastava, Kenji Kikuchi, Takuji Ishikawa

Journal of the Royal Society Interface　17　20200735　2020/10
Bacterial Biomechanics - From Individual Behaviors to Biofilm and the Gut Flora - Invited Peer-reviewed

Takuji Ishikawa, Toshihiro Omori, Kenji Kikuchi

APL Bioengineering　4　041504　2020/10
Elasto-hydrodynamic interaction of two swimming spermatozoa Peer-reviewed

Nanami Taketoshi, Toshihiro Omori, Takuji Ishikawa

Physics of Fluids　32　101901　2020/09
Stability of dancing Volvox Peer-reviewed

Takuji Ishikawa, T. J. Pedley, K. Drescher, R. E. Goldstein

Journal of Fluid Mechanics　903　A11　2020/09
Vulnerability of the skin barrier to mechanical rubbing Peer-reviewed

Kenji Kikuchi, Shunsuke Shigeta, Keiko Tsuruta-Numayama, Takuji Ishikawa

International Journal of Pharmaceutics　587　119708　2020/07
Active droplet driven by a collective motion of enclosed microswimmers Peer-reviewed

Zhihan Huang, Toshihiro Omori, Takuji Ishikawa

Physical Review E　102　022603　2020/07
How do C. elegans worms survive in highly viscous habitats? International-journal Peer-reviewed

Yuki Suzuki, Kenji Kikuchi, Keiko Numayama-Tsuruta, Takuji Ishikawa

The Journal of experimental biology　224　jeb.224691　2020/06/25

DOI： 10.1242/jeb.224691 　

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The nematode Caenorhabditis elegans is a filter feeder, which lives in various viscous habitats such as soil, the intestines of slugs, and rotting materials such as fruits and stems. C. elegans draws in suspensions of bacteria and separates bacteria from water using the pharyngeal pump. Although these worms often live in highly viscous habitats, it is still unclear how they survive in these environments by eating bacteria. In this study, we investigated the effects of suspension viscosity on the survival rate of malnutritioned worms by combining live imaging and scaling analyses. We found that survival rate decreased with increases in viscosity because the high viscosity suppressed the amount of food ingested. The same tendency was found in two feeding defective mutants, eat-6(ad467) and eat-6(ad997). We also found that the high viscosity weakened pump function, but the velocities in the pharynx were not zero, even in the most viscous suspensions. Finally, we estimated the amount of ingested food using scaling analyses, which provided a master curve of the experimental survival rates. These results illustrate that the survival rate of C. elegans worms is strongly dependent on the ingested bacteria per unit time associated with physical environments, such as the viscosity of food suspensions and the number density of bacteria. The pump function of the C. elegans pharynx is not completely lost even in fluids that have 105 times higher viscosity than water, which may contribute to their ability to survive around the world in highly viscous environments.
Rheology of a dilute suspension of deformable microswimmers Peer-reviewed

Hitomu Matsui, Toshihiro Omori, Takuji Ishikawa

Physics of Fluids　32　071902　2020/06
Harnessing random low Reynolds number flow for net migration Peer-reviewed

Takeru Morita, Toshihiro Omori, Yohei Nakayama, Shoichi Toyabe, Takuji Ishikawa

Physical Review E　101　063101　2020/06
Mechanical roles of anterograde and retrograde intestinal peristalses after feeding in a larval fish (Danio rerio). International-journal Peer-reviewed

Kenji Kikuchi, Hyeongtak Noh, Keiko Numayama-Tsuruta, Takuji Ishikawa

American journal of physiology. Gastrointestinal and liver physiology　318　(6)　G1013-G1021　2020/04/13

DOI： 10.1152/ajpgi.00165.2019 　

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Transport in gut is important not only for digestion, metabolism and nutrient uptake but also for microbiotic circumstance in the digestive tract, however, the effects of mixing and pumping in the intestine have not been fully clarified. Therefore, in this study, we quantitatively explored intestinal mixing and pumping represented using a dispersion coefficient and pressure rise in zebrafish larvae, which is a model organism for vertebrate digestive studies, over time by measuring transport phenomena after feeding. Here we provide the first quantitative evidence of the roles of anterograde and retrograde intestinal peristalses in the larval fish of Danio rerio after feeding in terms of digestive pumping and mixing functions by an in vivo imaging of intestinal propagation waves in the larval intestine. Peristaltic velocities in the anterior and posterior intestines change considerably after feeding for 5 hours, while the intervals and amplitudes remain almost constant. The intestinal transport is successively visualized after feeding to elimination. Moreover, the particle tracking velocimetry in the chyme leads our quantitative understanding of outstanding mixing and pumping functions in the anterior and posterior intestines by adopting physical parameters of diffusivity and pressure rise, respectively. From scaling analysis, we found that the anterior intestine maintains mixing for 5 hours from feeding, whereas the posterior intestine activates gradually pumping up. These results suggest that time change of pumping and mixing functions of intestinal peristalsis could considerably influence the nutrient uptake and microbiotic circumstance in the larval fish intestine.
Hydrodynamic interaction of two deformable torque swimmers Peer-reviewed

Hitomu Matsui, Toshihiro Omori, Takuji Ishikawa

Journal of Fluid Mechanics　894　A9　2020/04
The shape effect of flagella is more important than bottom-heaviness on passive gravitactic orientation in Chlamydomonas reinhardtii. International-journal Peer-reviewed

Azusa Kage, Toshihiro Omori, Kenji Kikuchi, Takuji Ishikawa

The Journal of experimental biology　223　(Pt 5)　jeb205989　2020/03

DOI： 10.1242/jeb.205989 　

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The way the unicellular, biflagellated, green alga Chlamydomonas orients upward has long been discussed in terms of both mechanics and physiology. In this study, we focus on the mechanics, i.e. the 'passive' mechanisms, of gravitaxis. To rotate the body upwards, cellular asymmetry is critical. Chlamydomonas can be depicted as a nearly spherical cell body with two anterior, symmetric flagella. The present study looks at the question of whether the existence of the flagella significantly affects torque generation in upward reorientation. The 'density asymmetry model' assumes that the cell is spherical and bottom-heavy and that the shape and weight of the flagella are negligible, while the 'shape asymmetry model' considers the shape of the flagella. Both our experimental and simulation results revealed a considerable contribution from shape asymmetry to the upward orientation of Chlamydomonas reinhardtii, which was several times larger than that of density asymmetry. From the experimental results, we also quantified the extent of bottom-heaviness, i.e. the distance between the centers of gravity and the figure when the cell body is assumed to be spherical. Our estimation was approximately 30 nm, only one-third of previous assumptions. These findings indicate the importance of the viscous drag of the flagella to the upward orientation, and thus negative gravitaxis, in Chlamydomonas.
Shape matters: Entrapment of a model ciliate at interfaces Peer-reviewed

Junichi Manabe, Toshihiro Omori and Takuji Ishikawa

Journal of Fluid Mechanics　892　A15　2020/03
Motility and Phototaxis of Gonium, the Simplest Differentiated Colonial Alga Peer-reviewed

Helene de Maleprade, Frederic Moisy, Takuji Ishikawa, Raymond E. Goldstein

Physical Review E　101　022416　2020/02
Particle selectivity of filtering by C. elegans Peer-reviewed

Yuki Suzuki, Kenji Kikuchi, Keiko Tsuruta-Numayama, Takuji Ishikawa

Theoretical & Applied Mechanics Letters　9　61-65　2019/11
Swimming mediated by ciliary beating: Comparison with a squirmer model Peer-reviewed

Hiroaki Ito, Toshihiro Omori, Takuji Ishikawa

Journal of Fluid Mechanics　874　774-796　2019/07
Swimming of ciliates under geometric constraints Invited Peer-reviewed

Takuji Ishikawa

Journal of Applied Physics　125　200901　2019/05
Shear-induced migration of a transmembrane protein within a vesicle Peer-reviewed

Koyo Nakamura, Toshihiro Omori, Takuji Ishikawa

Biophysical Journal　116　1483-1494　2019/04
Depth measurement of molecular permeation using inclined confocal microscopy International-journal Peer-reviewed

Kenji Kikuchi, Shunsuke Shigeta, Takuji Ishikawa

PLoS ONE　14　(3)　e0214504　2019/04

DOI： 10.1371/journal.pone.0214504 　

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We report a new technique for the high time-resolved depth measurement of molecular concentration distribution in a permeable hydrogel film with micro-depth precision. We developed an inclined observation technique in a laser-induced fluorescence (LIF) system, based on confocal microscopy, which measures the concentration distribution in the depth direction at less than micrometre intervals. The focal plane of confocal microscopy was tilted to enable simultaneous depth scanning in the microscopic field of view inside the permeable substrate. Our system achieved real-time and non-contact depth measurement of concentration distribution in the permeable hydrogel film. Simultaneous depth concentration measurement was realised with < 1 μm/pixel resolution over a maximum depth range of 570 μm, depending on the tilt angle of the stage and optical conditions. Our system measured the concentration of fluorescence materials based on the fluorescence intensities at several depth positions with a minimum concentration resolution of 1.3 nmol/L. Applying the proposed system to real-time concentration imaging, we successfully visualised unsteady concentration transport phenomena, and estimated the mass transport coefficient through the liquid-hydrogel interface. Our findings are useful for investigating the mass transport of physical, biological, and medical phenomena in permeable substrates.
Bacterial detachment from a wall with a line of bump Peer-reviewed

Jinyou Yang, Yuji Shimogonya, Takuji Ishikawa

Physical Review E　99　023104　2019/02
Swimming of spermatozoon in a Maxwell fluid Peer-reviewed

Toshihiro Omori, Takuji Ishikawa

Micromachines　10　78　2019/01
Stability of a dumbbell micro-swimmer Peer-reviewed

Takuji Ishikawa

Micromachines　10　33　2019/01
Biaxial fluid oscillations can propel a micro-capsule swimmer in an arbitrary direction Peer-reviewed

Takeru Morita, Toshihiro Omori, Takuji Ishikawa

Physical Review E　98　063102　2018/12
Elastohydrodynamic phase-lock in two rotating cilia Peer-reviewed

Toshihiro OMORI, Mingming LU, Takuji ISHIKAWA

Journal of Biomechanical Science and Engineering　13　17-00699　2018/12
Passive swimming of a micro-capsule in vertical fluid oscillation Peer-reviewed

Takeru Morita, Toshihiro Omori, Takuji Ishikawa

Physical Review E　98　023108　2018/08
Influence of cellular shape on sliding behavior of ciliates Peer-reviewed

Yukinori Nishigami, Takuya Ohmura, Atsushi Taniguchi, Shigenori Nonaka, Junichi Manabe, Takuji Ishikawa, Masatoshi Ichikawa

Communicative & Integrative Biology　11　e1506666　2018/08
Simulation of the nodal flow of Dpcd and Rfx3 mutant embryo: comparison of mechano-sensing and morphogen transport hypotheses Peer-reviewed

Toshihiro Omori, Katja Winter, Kyosuke Shinohara, Hiroshi Hamada, Takuji Ishikawa

Royal Society Open Science　5　180601　2018/08
Asymmetry in cilia configuration induces hydrodynamic phase locking Peer-reviewed

Keiji Okumura, Seiya Nishikawa, Toshihiro Omori, Takuji Ishikawa, Atsuko Takamatsu

Physical Review E　97　032411　2018/03
What causes the spatial heterogeneity of bacterial flora in the intestine of zebrafish larvae? Peer-reviewed

Jinyou Yang, Yuji Shimogonya, Takuji Ishikawa

Journal of Theoretical Biology　446　101-109　2018/03

DOI： 10.1016/j.jtbi.2018.03.007 　
Collective spreading of red blood cells flowing in a microchannel. International-journal Peer-reviewed

Cheng-Hsi Chuang, Kenji Kikuchi, Hironori Ueno, Keiko Numayama-Tsuruta, Takami Yamaguchi, Takuji Ishikawa

Journal of biomechanics　69　64-69　2018/03/01

DOI： 10.1016/j.jbiomech.2018.01.009 　

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Due to recent advances in micro total analysis system technologies, microfluidics provides increased opportunities to manipulate, stimulate, and diagnose blood cells. Controlling the concentration of cells at a given position across the width of a channel is an important aspect in the design of microfluidic devices. Despite its biomedical importance, the collective spreading of red blood cells (RBCs) in a microchannel has not yet been fully clarified. In this study, we experimentally investigated the collective spreading of RBCs in a straight microchannel, and found that RBCs initially distributed in one side of the microchannel spread to the spanwise direction during downstream flow. Spreading increased considerably as the hematocrit increased, though the flow rate had a small effect. We proposed a scaling argument to show that this spreading phenomenon was diffusive and mainly induced by cell-cell interactions. The dispersion coefficient was approximately proportional to the flow rate and the hematocrit. These results are useful in understanding collective behaviors of RBCs in a microchannel and in microcirculation.
Active particles in periodic lattices Peer-reviewed

Alexander Chamolly, Takuji Ishikawa, Eric Lauga

New Journal of Physics　19　115001-1-115001-13　2017/11/07
Swimming Behavior of Neutral Squirmer against Non-Slip Boundary

T. Ohmura, Y. Nishigami, J. Manabe, T. Ishikawa, M. Ichikawa

International Symposium on Fluctuation and Structure out of Equilibrium 2017 (SFS2017)　2017/11
Biomechanics of Tetrahymena escaping from dead ends

TAKUJI ISHIKAWA, KENJI KIKUCHI

Bulletin of the American Physical Society DFD2017　62　(14)　407-407　2017/11
Micro-navigation in complex periodic environments

ALEXANDER CHAMOLLY, TAKUJI ISHIKAWA, ERIC LAUGA

Bulletin of the American Physical Society DFD2017　62　(14)　58-58　2017/11
Transport phenomena in the intestine of zebrafish larvae

Jinyou Yang, Yuji Shimogonya, Takuji Ishikawa

5th Switzerland-Japan Workshop on Biomechanics (SJB2017)　46-46　2017/09
Nodal cilia-driven flow: Development of a computational model of the nodal cilia axoneme Peer-reviewed

T. Omori, H. Sugai, Y. Imai, T. Ishikawa

JOURNAL OF BIOMECHANICS　61　242-249　2017/08

DOI： 10.1016/j.jbiomech.2017.07.025 　

ISSN： 0021-9290

eISSN： 1873-2380
VISCOUS LOAD CHANGES THE CILIARY FORCE AND FLOW ON A TRACHEAL LUMEN

Takuji Ishikawa, Kenji Kikuchi, Tomofumi Haga, Keiko Numayama-Tsuruta, Hironori Ueno

The 26th Congress of the International Society of Biomechanics (ISB 2017)　2017/07
TRANSDERMAL DRUG DELIVERY ENHANCEMENT BY UNIDIRECTIONAL SKIN EXTENSION

Sho Sugawara, Kenji Kikuchi, Shunsuke Shigeta, Keiko Numayama-Tsuruta, Takuji Ishikawa

The 26th Congress of the International Society of Biomechanics (ISB 2017)　2017/07
UPSTREAM SWIMMING OF A SPERM CELL IN SHEAR FLOW

Toshihiro Omori, Takuji Ishikawa

The 26th Congress of the International Society of Biomechanics (ISB 2017)　2017/07
A BOUNDARY ELEMENT METHOD FOR CELLULAR SCALE PHYSIOLOGICAL FLOW PROBLEMS: PASSIVE MOTIONS OF RED BLOOD CELLS AND ACTIVE MOTIONS OF CILIA AND FLAGELLA Invited

Toshihiro Omori, Yohsuke Imai, Takami Yamaguchi, Takuji Ishikawa

The 26th Congress of the International Society of Biomechanics (ISB 2017)　2017/07

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Yamaguchi Medal 受賞講演
Shear-induced platelet aggregation and distribution of thrombogenesis at the stenotic vessel Peer-reviewed

Hiroki Kamada, Yohsuke Imai, Masanori Nakamura, Takuji Ishikawa, Takami Yamaguchi

Microcirculation　24　(4)　e12355-1-e12355-8　2017/05/15
Integrated nanobiomechanics of the living system

T. Yamaguchi, Y. Imai, T. Ishikawa

19th International Conference on Finite Elements in Flow Problems　2017/04
Mixing and pumping functions of the intestine of zebrafish larvae Peer-reviewed

Jinyou Yang, Yuji Shimogonya, Takuji Ishikawa

JOURNAL OF THEORETICAL BIOLOGY　419　152-158　2017/04

DOI： 10.1016/j.jtbi.2017.02.004 　

ISSN： 0022-5193

eISSN： 1095-8541
Effect of Fluid Viscosity on the Cilia-Generated Flow on a Mouse Tracheal Lumen Peer-reviewed

Kenji Kikuchi, Tomofumi Haga, Keiko Numayama-Tsuruta, Hironori Ueno, Takuji Ishikawa

ANNALS OF BIOMEDICAL ENGINEERING　45　(4)　1048-1057　2017/04

DOI： 10.1007/s10439-016-1743-y 　

ISSN： 0090-6964

eISSN： 1573-9686
Extending Whole Slide Imaging: Color Darkfield Internal Reflection Illumination (DIRI) for Biological Applications Peer-reviewed

Yoshihiro Kawano, Kana Namiki, Atsushi Miyawaki, Takuji Ishikawa

PLoS ONE　12　(1)　e0167774-1-e0167774-10　2017/01/13
RELATIONSHIP BETWEEN PERISTALTIC CONTRACTION AND GASTRIC MIXING

Yohsuke Imai, Taimei Miyagawa, Shunichi Ishida, Takami Yamaguchi, Takuji Ishikawa

Abstracts Book of the 16th International Conference on Biomedical Engineering　167　2016/12
DEVELOPMENT OF A BIOMECHANICAL MODEL OF CELL BEHAVIOR SUBJECTED TO CYCLIC STRETCH

Fumiyasu Saito, Yohsuke Imai, Shunichi Ishida, Toshihiro Omori, Takuji Ishikawa

Abstracts Book of the 16th International Conference on Biomedical Engineering　163　2016/12
A NUMERICAL ANALYSIS OF THE LATERAL MIGRATION OF FLOWING CELLS

Stephanie Nix, Yohsuke Imai, Takuji Ishikawa

Abstracts Book of the 16th International Conference on Biomedical Engineering　54　2016/12
NUMERICAL STUDY ON MIXING AND PUMPING FUNCTIONS GENERATED BY PERISTALSIS IN A ZEBRAFISH INTESTINE

Jinyou Yang, Yuji Shimogonya, Takuji Ishikawa

Abstracts Book of the 16th International Conference on Biomedical Engineering　44　2016/12
NUMERICAL SIMULATION OF A SPERM CELL IN SHEAR FLOW NEAR AN INFINITE BOUNDARY WALL

Toshihiro Omori, Takuji Ishikawa

Abstracts Book of the 16th International Conference on Biomedical Engineering　34　2016/12
Relationship between gastric motility and liquid mixing in the stomach Peer-reviewed

Taimei Miyagawa, Yohsuke Imai, Shunichi Ishida, Takuji Ishikawa

AMERICAN JOURNAL OF PHYSIOLOGY-GASTROINTESTINAL AND LIVER PHYSIOLOGY　311　(6)　G1114-G1121　2016/12

DOI： 10.1152/ajpgi.00346.2016 　

ISSN： 0193-1857

eISSN： 1522-1547
Precession in Stokes flow: spin and revolution of a bacterial flagellum

TAKUJI ISHIKAWA, YOICHIRO SAWANO, HIROMICHI WAKEBE, YUICHI INOUE, AKIHIKO ISHIJIMA, YUJI SHIMOGONYA

The 69th Annual Meetin g of The American Physical Society, Bulletin of the American Physical Society, DED 2016　61　546　2016/11
Numerical analysis of cell adhesion in capillary flow

NAOKI TAKEISHI, YOHSUKE IMAI, SHUNICHI ISHIDA, TOSHIHIRO OMORI, ROGER KAMM, TAKUJI ISHIKAWA

The 69th Annual Meetin g of The American Physical Society, Bulletin of the American Physical Society, DED 2016　61　72　2016/11
Reorientation of a single red blood cell during sedimentation Peer-reviewed

D. Matsunaga, Y. Imai, C. Wagner, T. Ishikawa

JOURNAL OF FLUID MECHANICS　806　102-128　2016/11

DOI： 10.1017/jfm.2016.601 　

ISSN： 0022-1120

eISSN： 1469-7645
Rheotaxis of a Sperm Cell in Shear Flow Near an Infinite Plane Wall, The 7th International Conference on Computational Methods

Toshihiro Omori, Takuji Ishikawa

The 7th International Conference on Computational Methods　MS-043　2016/08
Cell adhesion during bullet motion in capillaries Peer-reviewed

Naoki Takeishi, Yohsuke Imai, Shunichi Ishida, Toshihiro Omori, Roger D. Kamm, Takuji Ishikawa

AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY　311　(2)　H395-H403　2016/08

DOI： 10.1152/ajpheart.00241.2016 　

ISSN： 0363-6135

eISSN： 1522-1539
Bayesian Inference of Forces Causing Cytoplasmic Streaming in Caenorhabditis elegans Embryos and Mouse Oocytes Peer-reviewed

Ritsuya Niwayama, Hiromichi Nagao, Tomoya, S. Kitajima, Lars Hufnagel, Kyosuke Shinohara, Tomoyuki Higuchi, Takuji Ishikawa, Akatsuki Kimura

PLoS ONE　11　(7)　e0159917-1-e0159917-18　2016/07/29
Numerical methods for simulating blood flow at macro, micro, and multi scales Peer-reviewed

Yohsuke Imai, Toshihiro Omori, Yuji Shimogonya, Takami Yamaguchi, Takuji Ishikawa

Journal of Biomechanics　49　(11)　2221-2228　2016/07/26
Publisher: Elsevier Ltd
DOI： 10.1016/j.jbiomech.2015.11.047 　

ISSN： 1873-2380 0021-9290
Asymmetry of Arrangement Induces Phase Synchronization in Mouse Node Cilia

Keiji Okumura, Seiya Nishikawa, Toshihiro Omori, Takuji Ishikawa, Atsuko Takamatsu

26th IUPAP International conference on Statistical Physics　421　2016/07
Orientation change of a single red blood cell during sedimentation

Daiki Matsunaga, Yohsuke Imai, Christian Wagner, Takuji Ishikawa

Summer School 2016 Active Complex Matter　2016/07

DOI： 10.1017/jfm.2016.601 　
MEASURMENT OF DRUG PERMEATION IN THE SKIN BY A TWO PHOTON MICROSCOPY

Shunsuke Shigeta, Kenji Kikuchi, Keiko Numayama, Takuji Ishikawa

22nd Congress of the European Society of Biomechanics　OS21-1　2016/07
Bio-Micropump by Using a Flagellate Propulsive Force of Escherichia Coli

K. Kikuchi, R. Matsuura, H. Ueno, Y Imai, N. Matsuki, T. Yamaguchi, T. Ishikawa

The 24th World Congress on Engineering 2016　515-518　2016/07
Similarities and differences between flow mode of a leukocyte and circulating tumor cell in microvessels

Naoki Takeishi, Yohsuke Imai, Takami Yamaguchi, Takuji Ishikawa

Summer Biomechanics, Bioengineering and Biotransport Conference　742　2016/07
Lateral migration of a capsule in a parabolic flow Peer-reviewed

S. Nix, Y. Imai, T. Ishikawa

JOURNAL OF BIOMECHANICS　49　(11)　2249-2254　2016/07

DOI： 10.1016/j.jbiomech.2015.11.038 　

ISSN： 0021-9290

eISSN： 1873-2380
Enhancing cell-free layer thickness by bypass channels in a wall Peer-reviewed

M. Saadatmand, Y. Shimogonya, T. Yamaguchi, T. Ishikawa

JOURNAL OF BIOMECHANICS　49　(11)　2299-2305　2016/07

DOI： 10.1016/j.jbiomech.2015.11.032 　

ISSN： 0021-9290

eISSN： 1873-2380
Numerical methods for simulating blood flow at macro, micro, and multi scales Peer-reviewed

Yohsuke Imai, Toshihiro Omori, Yuji Shimogonya, Takami Yamaguchi, Takuji Ishikawa

JOURNAL OF BIOMECHANICS　49　(11)　2221-2228　2016/07

DOI： 10.1016/j.jbiomech.2015.11.047 　

ISSN： 0021-9290

eISSN： 1873-2380
Response to the Letter to the Editor "Hemodynamics in the Microcirculation" by A. G. Koutsiaris

Toshihiro Omori, Yohsuke Imai, Kenji Kikuchi, Takuji Ishikawa, Takami Yamaguchi

ANNALS OF BIOMEDICAL ENGINEERING　44　(4)　1323-1323　2016/04

DOI： 10.1007/s10439-016-1570-1 　

ISSN： 0090-6964

eISSN： 1573-9686
Upward swimming of a sperm cell in shear flow Peer-reviewed

Toshihiro Omori, Takuji Ishikawa

PHYSICAL REVIEW E　93　(3)　032402　2016/03

DOI： 10.1103/PhysRevE.93.032402 　

ISSN： 2470-0045

eISSN： 2470-0053
Inhomogeneous distribution of Chlamydomonas in a cylindrical container with a bubble plume Peer-reviewed

Yuki Nonaka, Kenji Kikuchi, Keiko Numayama-Tsuruta, Azusa Kage, Hironori Ueno, Takuji Ishikawa

BIOLOGY OPEN　5　(2)　154-160　2016/02

DOI： 10.1242/bio.015669 　

ISSN： 2046-6390
Nutrient uptake in a suspension of squirmers Peer-reviewed

Takuji Ishikawa, Shunsuke Kajiki, Yohsuke Imai, Toshihiro Omori

JOURNAL OF FLUID MECHANICS　789　481-499　2016/02

DOI： 10.1017/jfm.2015.741 　

ISSN： 0022-1120

eISSN： 1469-7645
Rheology of a dense suspension of spherical capsules under simple shear flow Peer-reviewed

D. Matsunaga, Y. Imai, T. Yamaguchi, T. Ishikawa

JOURNAL OF FLUID MECHANICS　786　110-127　2016/01

DOI： 10.1017/jfm.2015.666 　

ISSN： 0022-1120

eISSN： 1469-7645
A numerical model of a red blood cell infected by Plasmodium falciparum malaria: coupling cell mechanics with ligand-receptor interactions Peer-reviewed

Shunichi Ishida, Yohsuke Imai, Yuki Ichikawa, Stephanie Nix, Daiki Matsunaga, Toshihiro Omori, Takuji Ishikawa

SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS　17　(1)　454-461　2016

DOI： 10.1080/14686996.2016.1211462 　

ISSN： 1468-6996

eISSN： 1878-5514
Deformation of a micro-torque swimmer Peer-reviewed

Takuji Ishikawa, Tomoyuki Tanaka, Yohsuke Imai, Toshihiro Omori, Daiki Matsunaga

PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES　472　(2185)　20150604　2016/01

DOI： 10.1098/rspa.2015.0604 　

ISSN： 1364-5021

eISSN： 1471-2946
Flow of a circulating tumor cell and red blood cells in microvessels Peer-reviewed

Naoki Takeishi, Yohsuke Imai, Takami Yamaguchi, Takuji Ishikawa

PHYSICAL REVIEW E　92　(6)　063011　2015/12

DOI： 10.1103/PhysRevE.92.063011 　

ISSN： 1539-3755

eISSN： 1550-2376
Shape matters: Near-field fluid mechanics dominate the collective motions of ellipsoidal squirmers Peer-reviewed

K. Kyoya, D. Matsunaga, Y. Imai, T. Omori, T. Ishikawa

PHYSICAL REVIEW E　92　(6)　063027　2015/12

DOI： 10.1103/PhysRevE.92.063027 　

ISSN： 1539-3755

eISSN： 1550-2376
Torque-induced precession of bacterial flagella Peer-reviewed

Yuji Shimogonya, Yoichiro Sawano, Hiromichi Wakebe, Yuichi Inoue, Akihiko Ishijima, Takuji Ishikawa

SCIENTIFIC REPORTS　5　18488　2015/12

DOI： 10.1038/srep18488 　

ISSN： 2045-2322
Quantification of hydrodynamic factors influencing cell lateral migration

STEPHANIE NIX, YOHSUKE IMAI, TAKUJI ISHIKAWA

68th Annual Meeting of the Division of Fluid Dynamics, Bulletin of the American Physical Society, DFD 2015　60　116　2015/11/01
Deformable micro torque swimmer

TAKUJI ISHIKAWA, TOMOYUKI TANAKA, TOSHIHIRO OMORI, YOHSUKE IMAI

68th Annual Meeting of the Division of Fluid Dynamics, Bulletin of the American Physical Society, DFD 2015　60　72　2015/11/01
Hydrodynamic regulation and control of a micro-swimmer

Takuji Ishikawa

The 3rd International Workshops on Advances in Computational Mechanics(IWACOM-III)　133　2015/10/01
Rheological analysis of dense capsule suspensions – effect of volume fraction

Daiki Matsunaga, Yohsuke Imai, Christian Wagner, Takuji Ishikawa

The 3rd International Workshops on Advances in Computational Mechanics(IWACOM-III)　128　2015/10/01
Graphics processing unit computing of cellular flow and adhesion in microvessels

Yohsuke Imai, Naoki Takeishi, Shunichi Ishida, Takuji Ishikawa

The 3rd International Workshops on Advances in Computational Mechanics(IWACOM-III)　47　2015/10/01
Modeling mechanical behavior of precession of bacterial flagella

Yuji Shimogonya, Takuji Ishikawa

Computational Fluid Dynamics (CFD) in Medicine and Biology II　2015/09/01
Intergrated Computational Biomechanics of the Flow Phenomena in the Living Body

Takami Yamaguchi, Yosuke Imai, Toshihiro Omori, Kenji Kikuchi, Takuji Ishikawa

Computational Fluid Dynamics (CFD) in Medicine and Biology II　2015/09/01
Mechanics of Nodal Cilia in Early Mouse Embryo

Toshihiro Omori, Hiroto Sugai, Yohsuke Imai, Takuji Ishikawa

The 8th Asian-Pacific Conference on Biomechanics　PS8-15　2015/09/01
Digest Blood Sucked by a Female Mosquito

Kenji Kikuchi, Yosuke Imai, Takami Yamaguchi, Takuji Ishikawa

The 8th Asian-Pacific Conference on Biomechanics　PS8-14　2015/09/01
Effect of Mucous Viscosity on Ciliary Beat in the Tracheal Lumen

Tomofumi Haga, Kenji Kikuchi, Keiko Numayama-Tsuruta, Hironori Ueno, Takami Yamaguchi, Takuji Ishikawa

The 8th Asian-Pacific Conference on Biomechanics　PS8-13　2015/09/01
Development of a Numerical Model of Cytoskeleton Dynamics

Fumiyasu Saito, Yohsuke Imai, Shunichi Ishida, Toshihiro Omori, Takuji Ishikawa

The 8th Asian-Pacific Conference on Biomechanics　PS3-7　2015/09/01
Clarification of Relationship between Gastric Mixing and Movement of Wall

Taimei Miyagawa, Yohsuke Imai, Shunichi Ishida, Takami Yamaguchi, Takuji Ishikawa

The 8th Asian-Pacific Conference on Biomechanics　PS3-6　2015/09/01
Orientation Angle of a Single Red Blood Cell during Sedimentation

Daiki Matsunaga, Yohsuke Imai, Christian Wagner, Takuji Ishikawa

The 8th Asian-Pacific Conference on Biomechanics　PS3-2　2015/09/01
Hydrodynamic Interaction between the Small Microparticles and Red Blood Cells in Microchannel

Naoki Takeishi, Yohsuke Imai, Takami Yamaguchi, Takuji Ishikawa

The 8th Asian-Pacific Conference on Biomechanics　PS3-1　2015/09/01
Swimming Behavior of a Model Ciliate near a Fluid-Air or a Fluid-Solid Interface

Junichi Manabe, Toshihiro Omori, Yohsuke Imai, Takuji Ishikawa

The 8th Asian-Pacific Conference on Biomechanics　PS1-10　2015/09/01
Noninvasive Measurement of Drug Permeation in the Skin

Shunsuke Shigeta, Kenji Kikuchi, Keiko Numayama, Takuji Ishikawa

The 8th Asian-Pacific Conference on Biomechanics　PS1-9　2015/09/01
Hemodynamic Study on the Initiation of Cerebral Aneurysms Using Left-Right Comparison Method

Yuji Shimogonya, Shunichi Fukuda, Takuji Ishikawa, Takami Yamaguchi

The 8th Asian-Pacific Conference on Biomechanics　OS2-5　2015/09/01
A Numerical Simulation of Cytoadhesion and Rosette Formation of Red Blood Cells Infected by Malaria

Yohsuke Imai, Yuki Ichikawa, Shunichi Isida, Daiki Matsunaga, Stephanie Nix, Toshihiro Omori, Takami Yamaguchi, Takuji Ishikawa

The 8th Asian-Pacific Conference on Biomechanics　OS2-2　2015/09/01
Effect of Flow Curvature on the Migration of Blood Cells

Stephanie Nix, Yohsuke Imai, Takuji Ishikawa

The 8th Asian-Pacific Conference on Biomechanics　OS2-1　2015/09/01
Simulations of a swimming microorganism near an fluid-air or an fluid-solid interface

Junichi Manabe, Toshihiro Omori, Yohsuke Imai, Takuji Ishikawa

Computational Fluid Dynamics (CFD) in Medicine and Biology II　2015/09/01
Separation of motile bacteria using drift force near a wall

Takuji Ishikawa, Tatsuya Shioiri, Keiko Numayama-Tsuruta, Hironori Ueno, Yohsuke Imai, Takami Yamaguch

Computational Fluid Dynamics (CFD) in Medicine and Biology II　2015/09/01
A Stepping Microrobot Controlled by Flow Oscillations Peer-reviewed

Takuji Ishikawa, V. A. Vladimirov

JOURNAL OF FLUIDS ENGINEERING-TRANSACTIONS OF THE ASME　137　(8)　84501-1-84501-3　2015/08

DOI： 10.1115/1.4029840 　

ISSN： 0098-2202

eISSN： 1528-901X
Cellular Scale Physiological Flow: Active Swimming Sperm Cells and Passive Flowing Red Blood Cells

Toshihiro Omori, Takuji Ishikawa, Yohsuke Imai, Takami Yamaguchi

13th U.S. National Congress on Computational Mechanics　2015/07/01
Viscosity Reduction in Bimodal Suspensions of Two Types of Capsules

Yohsuke Imai, Hiroki Ito, Daiki Matsunaga, Toshihiro Omori, Takami Yamaguchi, Takuji Ishikawa

13th U.S. National Congress on Computational Mechanics　2015/07/01
Peclet Number Of Ciliary Transport On The Surface Of The Tracheal Lumen

Kouki Kiyota, Hironori Ueno, Keiko Numayama-Tsuruta, Yohsuke Imai, Takami Yamaguchi, Takuji Ishikawa

SB3C2015　223　2015/06/01
A Computational Study Of Red Blood Cells In Stokes Flow: From Single Cellular Mechanics To Suspension Rheology

Toshihiro Omori, Yohsuke Imai, Takami Yamaguchi, Takuji Ishikawa

SB3C2015　256　2015/06/01
Rheology of A Red Blood CEll Suspension Computing with A Boundary Element-Finite Wlement Coupled Method

Toshihiro Omori, Yohsuke Imai, Takuji Ishikawa

The 18th International Conference on Finite Elements in Flow Problems FEF2015　23　2015/03/01
Expanding Imaging Capabilities for Microfluidics: Applicability of Darkfield Internal Reflection Illumination (DIRI) to Observations in Microfluidics Peer-reviewed

Yoshihiro Kawano, Chino Otsuka, James Sanzo, Christopher Higgins, Tatsuo Nirei, Tobias Schilling, Takuji Ishikawa

PLOS ONE　10　(3)　e0116925　2015/03

DOI： 10.1371/journal.pone.0116925 　

ISSN： 1932-6203
Visualization of intestinal peristalsis of mosquito midgut by using micro x-ray imaging

Kenji Kikuchi, Yohsuke Imai, Takami Yamaguchi, Takuji Ishikawa

International Symposium on Integrated Nanobiomechanics　2015
Deformation of a spherical capsule under oscillating shear flow Peer-reviewed

D. Matsunaga, Y. Imai, T. Yamaguchi, T. Ishikawa

JOURNAL OF FLUID MECHANICS　762　288-301　2015

DOI： 10.1017/jfm.2014.649 　

ISSN： 0022-1120

eISSN： 1469-7645
Hemodynamics in the Microcirculation and in Microfluidics Peer-reviewed

Toshihiro Omori, Yohsuke Imai, Kenji Kikuchi, Takuji Ishikawa, Takami Yamaguchi

ANNALS OF BIOMEDICAL ENGINEERING　43　(1)　238-257　2015/01

DOI： 10.1007/s10439-014-1180-8 　

ISSN： 0090-6964

eISSN： 1573-9686
Swimming behavior of a model microorganism at a fluid-air interface

Junichi Manabe, Kohei Kyoya, Toshihiro Omori, Yohsuke Imai, Takuji Ishikawa

The Sixth International Symposium on Aero Aqua Bio-mechanisms　37　2014/11/01
Inhomogeneous distribution of cells in a microalgae suspension with aeration

Yuki Nonaka, Kenji Kikuchi, Keiko Numayama-Tsuruta, Azusa Kage, Hironori Ueno, Takuji Ishikawa

The Sixth International Symposium on Aero Aqua Bio-mechanisms　39　2014/11/01
Falling dynamics of immobilized Chlamydomonas reinhardtii

Azusa Kage, Kenji Kikuchi, Takuji Ishikawa

The Sixth International Symposium on Aero Aqua Bio-mechanisms　16　2014/11/01
Lateral migration of a spherical capsule near a plane wall in Stokes flow Peer-reviewed

S. Nix, Y. Imai, D. Matsunaga, T. Yamaguchi, T. Ishikawa

Physical Review E - Statistical, Nonlinear, and Soft Matter Physics　90　(4)　2014/10/15

DOI： 10.1103/PhysRevE.90.043009 　

ISSN： 1539-3755

eISSN： 1550-2376
Lateral migration of a spherical capsule in a near-wall shear flow Peer-reviewed

S. Nix, Y. Imai, D. Matsunaga, T. Yamaguchi, T. Ishikawa

Physical Review E　90　043009　2014/10/05
Oxygen supersaturated fluid using fine micro/nanobubbles Peer-reviewed

N. Matsuki, T. Ishikawa, S. Ichiba, N. Shiba, Y. Ujike, T. Yamaguchi

International Journal of Nanomedicine　9　1-11　2014/10/02

DOI： 10.2147/IJN.S68840 　
Enhancing Cell Free Layer Thickness by Bypass Channels in a Wall

Maryam Saadatmand, Takami Yamaguchi, Takuji Ishikawa

Eleventh International Conference on Flow Dynamics　310-311　2014/10/01
Biological Flow generated by Cilla and Flagella

Takuji Ishikawa

Eleventh International Conference on Flow Dynamics　320-321　2014/10/01
Hydrodynamic interaction between two red blood cells in simple shear flow: its impact on the rheology of a semi-dilute suspension Peer-reviewed

Toshihiro Omori, Takuji Ishikawa, Yohsuke Imai, Takami Yamaguchi

COMPUTATIONAL MECHANICS　54　(4)　933-941　2014/10

DOI： 10.1007/s00466-014-0997-1 　

ISSN： 0178-7675

eISSN： 1432-0924
Modeling of Flow in the Stomach

Yohsuke Imai, Ikuma Kobayashi, Taimei Miyagawa, Shunichi Ishida, Takuji Ishikawa, Takami Yamaguchi

THE FOURTH JAPAN-SWITZERLAND WORKSHOP ON BIOMECHANICS　102　2014/09/01
Biological Flow generated by Cilla and Flagella

Takuji Ishikawa

THE FOURTH JAPAN-SWITZERLAND WORKSHOP ON BIOMECHANICS　110　2014/09/01
Dispersion of model microorganisms swimming in a nonuniform suspension Peer-reviewed

Takuji Ishikawa, T. J. Pedley

PHYSICAL REVIEW E　90　(3)　033008　2014/09

DOI： 10.1103/PhysRevE.90.033008 　

ISSN： 1539-3755

eISSN： 1550-2376
Numerical modeling of cellular flow and adhesion in microvessels Peer-reviewed

Yohsuke Imai, Naoki Takeishi, Akihisa Ami, Takami Yamaguchi, Takuji Ishikawa

Transactions of Japanese Society for Medical and Biological Engineering　52　45　2014/08/17
Publisher: Japan Soc. of Med. Electronics and Biol. Engineering
DOI： 10.11239/jsmbe.52.SY-45 　

ISSN： 1347-443X 1881-4379
Collective swimming of model micro-organisms

Takuji Ishikawa

JSMB/SMB Osaka 2014　43　2014/08/10
A numerical method for simulating gastricflow

Taimei Miyagawa, Yohsuke Imai, Takami Yamaguchi, takuji Ishikawa

11th World Congress on Computational Mechanics　303　2014/07/10
Rheological analysis of capsule suspensions containing different size capsules

Hiroki Ito, Yohsuke Imai, Daiki Matsunaga, Toshihiro Omori, Takami Yamaguchi, Takuji Ishikawa

11th World Congress on Computational Mechanics　303　2014/07/10
Rheological analysis of dense capsule suspension under simple shear flow condition

Daiki Matsunaga, Yohsuke Imai, Takami Yamaguchi, Takuji Ishikawa

Dyna Caps 2014　2014/07/10
Numerical Analysis of Capsule Suspensions Containing Two Different siza Capsules

Hiroki Ito, Yohsuke Imai, Daiki Matsunaga, Toshihiro Omori, Takami Yamaguchi, Takuji Ishikawa

Dyna Caps 2014　2014/07/10
Collective swimming of ellipoidal squimers

Takuji Ishikawa, Kohei Kyoya, Daiki Matsunaga, Yohsuke Imai, Toshihiro Omori

Dyna Caps 2014　2014/07/10
Margination of large cells in microchannels

Yohsuke Imai, Naoki Takeishi, Takami Yamaguchi, Takuji Ishikawa

Dyna Caps 2014　2014/07/10
Development of a numerical model for analysis of ciliary motions

H. Sugai, T. Omori, Y. Imai, T. Ishikawa

7th WORLD CONGRESS OF BIOMECHANICS　2014/07/10
Effect of Shear Gradient and Wall on Capsule Lateral Migration

S. Nix, Y. Imai, T. Yamaguchi, T. Ishikawa

7th WORLD CONGRESS OF BIOMECHANICS　2014/07/10
Multi-scale computational study on the formation and destruction of primary thrombus under the influence of the blood flow and red blood cells

H. Kmada, Y. Imai, T. Ishikawa, T. Yamaguchi

7th WORLD CONGRESS OF BIOMECHANICS　2014/07/10
Rheology of a red blood cell suspension in a simpleshear flow

T. Omori, Y. Imai, D, Mtsunaga, T. Yamaguchi, T, Ishikawa

7th WORLD CONGRESS OF BIOMECHANICS　2014/07/10
A numerical simulation on the motion ofmalaria-infected cells in microcirculatory blood flow

Y. Imai, A, Ami, T. Yamaguchi, T, Ishikawa

7th WORLD CONGRESS OF BIOMECHANICS　2014/07/10
Collective motions of ellipsoidal squirmers in a dense suspension

T. Ishikawa, K. Kyoya, D. Matsunaga, Y.Imai. T. Omori

7th WORLD CONGRESS OF BIOMECHANICS　2014/07/10
Numerical analysis of hydrodynamic behavior of circulating tumor cells in microchannels

N. Takeishi, Y. Imai, T. Yamaguchi, T. Ishikawa

7th WORLD CONGRESS OF BIOMECHANICS　2014/07/10
Distrlibution of Microalgae Cells in a Tube Container with Aeration

Yuki Nonaka, Kenji Kikuchi, Keiko Numayama-Tsuruta, Azusa Kage, Hironori Ueno, Takuji Ishikawa

Internationnal Symposium on Integrated Nanobiomechanics　21-22　2014/07/05
Effect of Rheological Properties on Cilliary Flow in the Airway

Tomofumi Haga, Kenji Kikuchi, Hironori Ueno, Keiko Numayama-Tsuruta, Takuji Ishikawa

Internationnal Symposium on Integrated Nanobiomechanics　19-20　2014/07/05
Development of an Intracellular Structure Model for Ciliary Motion Analysis

Hiroto Sugai, Toshihiro Omori, Yohsuke Imai, Takami Yamaguchi, Takuji Ishikawa

Internationnal Symposium on Integrated Nanobiomechanics　17-18　2014/07/05
Nutrient Uptake in a Suspension of Model Microorganisms

Takuji Ishikawa, Shunsuke Kajiki, Yohsuke Imai, Toshihiro Omori

Internationnal Symposium on Integrated Nanobiomechanics　15-16　2014/07/05
Capsule Lateral Migration in an Unbounded Plane Poiseuille Flow and Near-wall Shear Flow

Stephanie Nix, Yohsuke Imai, Takami Yamaguchi, Takuji Ishikawa

Internationnal Symposium on Integrated Nanobiomechanics　13-14　2014/07/05
Rheology of a Red Blood Cell Suspension from Dilute to Semi-dilute Regime

Toshihiro Omori, Yohsuke Imai, Takami Imai, Takuji Ishikawa

Internationnal Symposium on Integrated Nanobiomechanics　11-12　2014/07/05
Hydrodynamic Interction between a Circulating Tumor Cell and Blood Cells in Microcirculation

Naoki Takeishi, Yohsuke Imai, Takami Yamaguchi, Takuji Ishikawa

Internationnal Symposium on Integrated Nanobiomechanics　9-10　2014/07/05
Numerical Modeling of the Adhesion of Red Blood Cells Infected by Plasmodium Falciparum Malaria in Microcirculatory Blood Flow

Yohsuke Imai, Akihisa Ami, Takami Yamaguchi, Takuji Ishikawa

Internationnal Symposium on Integrated Nanobiomechanics　7-8　2014/07/05
A Numerical Analysis of Cellular Adhesion to Planar Wall Mediated by Ligand-Receptor Interactions

Yuki Ichikawa, Yohsuke Imai, Daiki Matsunaga, Stephanie Nix, Takami Yamaguchi, Takuji Ishikawa

Internationnal Symposium on Integrated Nanobiomechanics　5-6　2014/07/05
Computational Study on Thrombogenesis

Hiroki Kamada, Yohsuke Imai, Takuji Ishikawa, Takami Ymaguchi

Internationnal Symposium on Integrated Nanobiomechanics　3-4　2014/07/05
Shear Stress Distribution in the Stomach

Taimei Miyagawa, Yohsuke Imai, Sunichi Ishida, Takami Yamaguchi, Takuji Ishikawa

Internationnal Symposium on Integrated Nanobiomechanics　1-2　2014/07/05
Structure of Dimeric Axonemal Dynein in Cilia Suggests an Alternative Mechanism of Force Generation Peer-reviewed

Hironori Ueno, Khanh Huy Bui, Takuji Ishikawa, Yohsuke Imai, Takami Yamaguchi, Takashi Ishikawa

CYTOSKELETON　71　(7)　412-422　2014/07

DOI： 10.1002/cm.21180 　

ISSN： 1949-3584

eISSN： 1949-3592
Nutrient uptake in a suspension of model microorganisms

Takuji Ishikawa, Shunsuke Kajiki, Yohsuke Imai, Toshihiro Omori

COMPSAFE　347-348　2014/04/02
Fluid mechanics of swimming bacteria with multiple flagella Peer-reviewed

Philipp Kanehl, Takuji Ishikawa

PHYSICAL REVIEW E　89　(4)　042704　2014/04

DOI： 10.1103/PhysRevE.89.042704 　

ISSN： 1539-3755

eISSN： 1550-2376
Rheological analysis of dense capsule suspension under Stokes flow condition

Daiki Matsunaga, Yohsuke Imai, Takami Yamaguchi, Takuji Ishikawa

Advances in Computational Fluid-Structure Interaction and Flow Simulation　Poster Session　2014/03/02
Numerical analysis of a red blood cell flowing through a thin micropore Peer-reviewed

Toshihiro Omori, Haruki Hosaka, Yohsuke Imai, Takami Yamaguchi, Takuji Ishikawa

Physical Review E - Statistical, Nonlinear, and Soft Matter Physics　89　(1)　2014/01/13

DOI： 10.1103/PhysRevE.89.013008 　

ISSN： 1539-3755 1550-2376
Flow-induced deformation of a capsule in unbounded stokes flow Peer-reviewed

Toshihiro Omori, Takuji Ishikawa, Yohsuke Imai, Takami Yamaguchi

Lecture Notes in Computational Vision and Biomechanics　12　101-117　2014
Publisher: Kluwer Academic Publishers
DOI： 10.1007/978-94-007-7769-9_6 　

ISSN： 2212-9413 2212-9391
Fluctuation of cilia-generated flow on the surface of the tracheal lumen Peer-reviewed

Kouki Kiyota, Hironori Ueno, Keiko Numayama-Tsuruta, Tomofumi Haga, Yohsuke Imai, Takami Yamaguchi, Takuji Ishikawa

AMERICAN JOURNAL OF PHYSIOLOGY-LUNG CELLULAR AND MOLECULAR PHYSIOLOGY　306　(2)　L144-L151　2014/01

DOI： 10.1152/ajplung.00117.2013 　

ISSN： 1040-0605

eISSN： 1522-1504
Numerical analysis of a red blood cell flowing through a thin micropore Peer-reviewed

Toshihiro Omori, Haruki Hosaka, Yohsuke Imai, Takami Yamaguchi, Takuji Ishikawa

PHYSICAL REVIEW E　89　(1)　013008　2014/01

DOI： 10.1103/PhysRevE.89.013008 　

ISSN： 2470-0045

eISSN： 2470-0053
Leukocyte margination at arteriole shear rate Peer-reviewed

Naoki Takeishi, Yohsuke Imai, Keita Nakaaki, Takami Yamaguchi, Takuji Ishikawa

Physiological Reports　2　(6)　e12037　2014
Publisher: American Physiological Society
DOI： 10.14814/phy2.12037 　

ISSN： 2051-817X
A full GPU implementation of a numerical method for simulating capsule suspensions Peer-reviewed

Daiki Matsunaga, Yohsuke Imai, Toshihiro Omori, Takuji Ishikawa, Takami Yamaguchi

Journal of Biomechanical Science and Engineering　9　(3)　1-16　2014
Publisher: Japan Society of Mechanical Engineers
DOI： 10.1299/jbse.14-00039 　

ISSN： 1880-9863
Separation of motile bacteria using drift velocity in a microchannel Peer-reviewed

Takuji Ishikawa, Tatsuya Shioiri, Keiko Numayama-Tsuruta, Hironori Ueno, Yohsuke Imai, Takami Yamaguchi

LAB ON A CHIP　14　(5)　1023-1032　2014

DOI： 10.1039/c3lc51302e 　

ISSN： 1473-0197

eISSN： 1473-0189
A numerical analysis of a capsule containing multiple small capsules in simple shear flow

Yuki Ichikawa, Yohsuke Imai, Daiki Matsunaga, Takami Yamaguchi, Takuji Ishikawa

APCOM2013 & ISCM2013 Conference Handbook　15　2013/12/11
Numerical analysis of margination of a cancer cell in microcirculation

N. Takeishi, Y. Imai, T. Yamaguchi, T. Ishikawa

APCOM2013 & ISCM2013 Conference Handbook　18　2013/12/11
Solid particle motion in the stomach during gastric mixing

Taimei Miyagawa, Yohsuke Imai, Takami Yamaguchi, Takuji Ishikawa

The15th International Conference on Biomedical Enginnering　17-18　2013/12/04
Collective Swimming in a Suspension of Ellipsoidal Squirmers

Kohei KYOYA, Daiki MATSUNAGA, Yohsuke IMAI, Takami YAMAGUCHI, Takuji ISHIKAWA

Bulletin of the American Physical Society　58　410　2013/11/26
Nutrient uptake in a suspension of squirmers

Shunsuke Kajiki, Yohsuke Imai, Takami Yamaguchi, Takuji Ishikawa

Bulletin of the American Physical Society　58　409　2013/11/26
Viscoelasticity of dilute capsule suspension under Stokes flows

Daiki Matsunaga, Yohsuke Imai, Takami Yamaguchi, Takuji Ishikawa

Bulletin of the American Physical Society　58　97　2013/11/24
Viscosity of Dense Capsule Suspension Under Simple Shear FLow Condition

Daiki Matsunaga, Yohsuke Imai, Takami Yamaguchi, Takuji Ishikawa

7th East Asian Consortium on Biomedical Engineering, Proceeding Book　80-81　2013/11/19
Margination of leukocyte in different sizes of circular micro-channel

Naoki takeishi, Yohsuke Imai, Takami Yamaguchi, Takuji Ishikawa

7th East Asian Consortium on Biomedical Engineering, Proceeding Book　78-79　2013/11/19
Hydrodynamical entrapment of ciliates at the air-liquid interface Peer-reviewed

J. Ferracci, H. Ueno, K. Numayama-Tsuruta, Y. Imai, T. Yamaguchi, T. Ishikawa

PLoS ONE　8　e75238　2013/10/01

DOI： 10.1371/journal.pone.0075238 　
Behavior of red blood cells in a hyperbolic microchannel: the extensional flow effect Peer-reviewed

T. Yaginuma, M. S. N. Oliveira, R. Lima, T. Ishikawa, T. Yamaguchi

Biomicrofluidics　7　054110-106　2013/09/02

DOI： 10.1063/1.4820414 　
Human red blood cell behavior under homogeneous extensional flow in a hyperbolic-shaped microchannel Peer-reviewed

T. Yaginuma, M. S. N. Oliveira, R. Lima, T. Ishikawa, T. Yamaguchi

BIOMICROFLUIDICS　7　(5)　2013/09

DOI： 10.1063/1.4820414 　

ISSN： 1932-1058
Simulation of nutrient uptake of swimming model microorganisms

S. Kajiki, D. Matsunaga, Y. Imai, T. Yamaguchi, T. Ishikawa

APCB2013 Proceedings　S12　2013/08/30
Effect of Aeration on the Bioconvection Pattern in a Microalgae Suspension

Y. Nonaka, H. Ueno, K. Numayama, T. Omori, Y. Imai, T. Yamaguchi, T. Ishikawa

APCB2013 Proceedings　S12-002　2013/08/30
Modeling of cytoadhesion in malaria infection

A. Ami, Y. Imai, T. Ishikawa, T. Yamaguchi

APCB2013 Proceedings　S4-3　2013/08/30
Mechanism of capsule migration near a plane wall

S. Nix, Y. Imai, D. Matsunaga, T. Yamaguchi, T. Ishikawa

APCB2013 Proceedings　S4-020　2013/08/30
Numerical simulation of motion of solid particles in the stomach

T. Miyagawa, Y. Imai, T. Yamaguchi, T. Ishikawa

APCB2013 Proceedings　S4-019　2013/08/30
Margination of white blood cell in various sizes of circular micro-channel

N. Takeishi, Y. Imai, T. Ishikawa, T. Yamaguchi

APCB2013 Proceedings　S4-3　2013/08/30
Collective Swimming of Ellipsoidal Microorganisms

K. Kyoya, D. Matsunaga, Y. Imai, T. Yamaguchi, T. Ishikawa

APCB2013 Proceedings　S4-014　2013/08/30
A Numerical Analysis of the Rheorogy of Capsule Suspensions Containing Different Size Capsules

H. Ito, Y. Imai, D. Matsunaga, T. Yamaguchi, T. Ishikawa

APCB2013 Proceedings　S4-015　2013/08/30
Integrated Biomechanics for Physiological Flow Problems

T. Yamaguchi, Y. Imai, T. Omori, H. Ueno, K. Numayama-Tsuruta, T. Ishikawa

APCB2013 The7thAsian Pacific Conference on Biomechanics　ILS4-009　2013/08/29
COMPUTATIONAL BIOMECHANICS ON BLOOD FLOW FROM CELLULAR TO

T. yamaguchi, Y. Imai, T. Ishikawa

COMPDYN 2013　S2090　2013/06/13
Shear-induced diffusion of red blood cells in a semi-dilute suspension Peer-reviewed

T. Omori, T. Ishikawa, Y. Imai, T. Yamaguchi

Journal of Fluid Mechanics　724　154-174　2013/06/10

DOI： 10.1017/jfm.2013.159 　

ISSN： 0022-1120 1469-7645
Computational simulation of thrombus formation regulated by platelet membrane receptors and blood shear Peer-reviewed

H. Kamada, Y. Imai, M. Nakamura, T. Ishikawa, T. Yamaguchi

Microvascular Research　89　95-106　2013/06/02

DOI： 10.1016/j.mvr.2013.05.006 　
Asymmetric rotational stroke in mouse node cilia during left-right determination Peer-reviewed

Atsuko Takamatsu, Takuji Ishikawa, Kyosuke Shinohara, Hiroshi Hamada

Physical Review E - Statistical, Nonlinear, and Soft Matter Physics　87　(5)　050701(R)　2013/05/15

DOI： 10.1103/PhysRevE.87.050701 　

ISSN： 1539-3755 1550-2376
The near-wall motion of a capsule in stokes flow

S. Nix, Y. Imai, D. Matsunaga, T. Ishikawa, T. Yamaguchi

6th East Asian Pacific Student Workshop on Nano-Biomedical Engineering　52-53　2013/03
Numerical simulation of adhesion of malaria-infected red blood cells

A. Ami, Y. Imai, T. Ishikawa, T. Yamaguchi

6th East Asian Pacific Student Workshop on Nano-Biomedical Engineering　38-39　2013/03
Numerical analysis of swimming microorganisms by a boundary element method

K. Kyoya, D. Matsunaga, Y. Imai, T. Yamaguchi, T. Ishikawa

6th East Asian Pacific Student Workshop on Nano-Biomedical Engineering　44-45　2013/03
Numerical analysis of dynamics of solid particles in the stomach

T. Miyagawa, Y. Imai, T. Ishikawa, T. Yamaguchi

6th East Asian Pacific Student Workshop on Nano-Biomedical Engineering　48-49　2013/03
Margination of various cells in microcirculation

N. Takeishi, Y. Imai, T. Ishikawa, T. Yamaguchi

6th East Asian Pacific Student Workshop on Nano-Biomedical Engineering　36-37　2013/03
Gradient diffusion of red blood cells in blood flow through a Y-shape microchannel

C. Chuang, T. Ishikawa, H. Ueno, K. Numayama-Tsuruta, Y. Imai, T. Yamaguchi

6th East Asian Pacific Student Workshop on Nano-Biomedical Engineering　78-79　2013/03
A numerical analysis of complex viscosity of dilute capsule suspension

D. Matsunaga, Y. Imai, T. Ishikawa, T. Yamaguchi

6th East Asian Pacific Student Workshop on Nano-Biomedical Engineering　104-105　2013/03
A numerical analysis of bimodal capsule suspensions

H. Ito, Y. Imai, D. Matsunaga, T. Ishikawa, T. Yamaguchi

6th East Asian Pacific Student Workshop on Nano-Biomedical Engineering　106-107　2013/03
Active Suspensions of Swimming Microorganisms Invited

T. Ishikawa

Int. Symp. Self-organization and Emergent Dynamics in Active Soft Matter Abstracts　14　2013/02/01
Membrane tension of red blood cells pairwisely interacting in simple shear flow Peer-reviewed

Toshihiro Omori, Takuji Ishikawa, Yohsuke Imai, Takami Yamaguchi

Journal of Biomechanics　46　(3)　548-553　2013/02/01

DOI： 10.1016/j.jbiomech.2012.09.017 　

ISSN： 0021-9290 1873-2380
Antral recirculation in the stomach during gastric mixing Peer-reviewed

Yohsuke Imai, Ikuma Kobayashi, Shunichi Ishida, Takuji Ishikawa, Martin Buist, Takami Yamaguchi

American Journal of Physiology - Gastrointestinal and Liver Physiology　304　(5)　G536-G542　2013

DOI： 10.1152/ajpgi.00350.2012 　

ISSN： 0193-1857 1522-1547
Computational analysis on the mechanical interaction between a thrombus and red blood cells: Possible causes of membrane damage of red blood cells at microvessels Peer-reviewed

Hiroki Kamada, Yohsuke Imai, Masanori Nakamura, Takuji Ishikawa, Takami Yamaguchi

MEDICAL ENGINEERING & PHYSICS　34　(10)　1411-1420　2012/12

DOI： 10.1016/j.medengphy.2012.01.003 　

ISSN： 1350-4533
Models and Numerical Methods for a Suspension of Swimming Microorganisms: Review Peer-reviewed

Takuji Ishikawa

INTERNATIONAL JOURNAL OF OFFSHORE AND POLAR ENGINEERING　22　(4)　270-275　2012/12

ISSN： 1053-5381
3D-PTV measurement of the phototactic movement of algae in shear flow

T. Maeda, T. Ishikawa, H. Ueno, K. Numayama-Tsuruta, Y. Imai, T. Yamaguchi

Bulletin of the American Physical Society　57　49　2012/11/20
Measurement of ciliary flow generated on the surface of tracheal

K. Kiyota, H. Ueno, T. Ishikawa, K. Numayama-Tsuruta, Y. Imai, T. Omori, T. Yamaguchi

Bulletin of the American Physical Society　57　334　2012/11/20
Off-plane motion of a non-spherical capsule in simple shear flow

T. Omori, T. Ishikawa, Y. Imai, T. Yamaguchi

Bulletin of the American Physical Society　57　331　2012/11/20
Analysis of red blood cell behavior in a narrow tube

H. Hosaka, T. Omori, Y. Imai, T. Yamaguchi, T. Ishikawa

Bulletin of the American Physical Society　57　330　2012/11/20
Hydrodynamical entrapment of ciliates at the air-liquid interface

J. Ferracci, H. Ueno, K. Numayama-Tsuruta, Y. Imai, T. Yamaguchi, T. Ishikawa

Bulletin of the American Physical Society　57　107　2012/11/20
Gradient diffusion of red blood cells in blood flow through a Y-shape microchannel

C. Chuang, T. Ishikawa, H. Ueno, K. Numayama-Tsuruta, Y. Imai, T. Yamaguchi

Bulletin of the American Physical Society 65th Annual Meeting of the APS Division of Fluid Dynamics　330-330　2012/11
Tension of red blood cell membrane in simple shear flow Peer-reviewed

T. Omori, T. Ishikawa, D. Barthes-Biesel, A. -V. Salsac, Y. Imai, T. Yamaguchi

PHYSICAL REVIEW E　86　(5)　056321　2012/11

DOI： 10.1103/PhysRevE.86.056321 　

ISSN： 1539-3755
Lateral migration of capsules in a near-wall shear flow

S. Nix, Y. Imai, D. Matsunaga, T. Ishikawa, T. Yamaguchi

JSME-CMD ICMS2012　USB　2012/10/20
Development of a GPU-Implemented BEM solver for biological cell suspensions

Y. Imai, D. Matsunaga, K. Kyoya, T. Omori, T. Ishikawa, T. Yamaguchi

JSME-CMD ICMS2012　USB　2012/10/20
Mouse respiratory cilia with the asymmetric axonemal structure on sparsely distributed ciliary cells can generate overall directional flow Peer-reviewed

Hironori Ueno, Takuji Ishikawa, Khanh Huy Bui, Kohsuke Gonda, Takashi Ishikawa, Takami Yamaguchi

NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE　8　(7)　1081-1087　2012/10

DOI： 10.1016/j.nano.2012.01.004 　

ISSN： 1549-9634
Quantification of red blood cell deformation at high-hematocrit blood flow in microvessels Peer-reviewed

Davod Alizadehrad, Yohsuke Imai, Keita Nakaaki, Takuji Ishikawa, Takami Yamaguchi

JOURNAL OF BIOMECHANICS　45　(15)　2684-2689　2012/10

DOI： 10.1016/j.jbiomech.2012.08.026 　

ISSN： 0021-9290

eISSN： 1873-2380
Role of fluid mechanics in collective motions of bacteria

T. Ishikawa, N. Yoshida, H. Ueno, M. Wiedeman, Y. Imai, T. Yamaguchi

9th International Conference on Flow Dynamics　732-733　2012/09/20
Computational analysis on the mechanical interaction between a thrombus and red blood cells

H. Kamada, Y. Imai, M. Nakamura, T. Ishikawa, T. Yamaguchi

ECCOMAS 2012 Congress　CD-ROM　2012/09/20
Vertical dispersion of model microorganisms in horizontal shear flow Peer-reviewed

Takuji Ishikawa

JOURNAL OF FLUID MECHANICS　705　98-119　2012/08

DOI： 10.1017/jfm.2012.116 　

ISSN： 0022-1120
Particle based simulation of microcirculation using a parallel computation

T. Yamaguchi, Y. Imai, T. Ishikawa

14th Int.l Cong. Biorheology and 7th Int. Conf. Clinical Hemorheology　181　2012/07/20
Reorientation of a non-spherical capsule in shear flow

T. Ishikawa, T. Omori, Y. Imai, T. Yamaguchi

Abstracts 23rd Int. Cong. Theor. Appl. Math.　106　2012/07/20
Hemodynamics in the pulmonary artery of a patient with pneumothorax Peer-reviewed

J-J Christophe, T. Ishikawa, Y. Imai, K. Takase, M. Thiriet, T. Yamaguchi

MEDICAL ENGINEERING & PHYSICS　34　(6)　725-732　2012/07

DOI： 10.1016/j.medengphy.2011.09.016 　

ISSN： 1350-4533

eISSN： 1873-4030
Hydrodynamic entrapment of ciliates at the air-liquid interface

J. Ferracci, H. Ueno, K. Numayama-Tsuruta, Y. Imai, T. Yamaguchi, T. Ishikawa

Softflow 2012 - Biological Complex Fluids　36-37　2012/06/22
Dynamics of capsules near a plane wall

S. Nix, Y. Imai, T. Ishikawa, T. Yamaguchi

Softflow 2012 - Biological Complex Fluids　76　2012/06/22
Analysis of ciliary motion and the axonemal structure in the mouse respiratory cilia Peer-reviewed

H. Ueno, T. Ishikawa, K. H. Bui, K. Gonda, T. Ishikawa, T. Yamaguchi

ASME 2012 Summer Bioengineering Conference　CD-ROM　2012/06/20

DOI： 10.1115/SBC2012-80232 　
Dynamics of a spherical capsule in a near-wall shear flow Peer-reviewed

S. Nix, Y. Imai, D. Matsunaga, T. Ishikawa, T. Yamaguchi

ASME 2012 Summer Bioengineering Conference　CD-ROM　2012/06/20

DOI： 10.1115/SBC2012-80518 　
Development of a numerical model for micro-scale blood flow simulation using GPGPU Peer-reviewed

N. Takeishi, Y. Imai, K. Nakaaki, T. Ishikawa, T. Yamaguchi

ASME 2012 Summer Bioengineering Conference　CD-ROM　2012/06/20

DOI： 10.1115/SBC2012-80028 　
Development of a multi-phase flow model for simulating solid particle motion in the stomach Peer-reviewed

T. Miyagawa, Y. Imai, I. Kobayashi, T. Ishikawa, T. Yamaguchi

ASME 2012 Summer Bioengineering Conference　CD-ROM　2012/06/20

DOI： 10.1115/SBC2012-80891 　
Double-layer representation of model microorganisms by a boundary element method Peer-reviewed

K. Kyoya, Y. Imai, T. Yamaguchi, T. Ishikawa

ASME 2012 Summer Bioengineering Conference　CD-ROM　2012/06/20

DOI： 10.1115/SBC2012-80234 　
Transport Phenomena in Suspensions of Swimming Microorganisms

T. Ishikawa

Biological Complex Fluids　53　2012/06/20
Blood oxygenation using microbubble suspensions Peer-reviewed

Noriaki Matsuki, Shingo Ichiba, Takuji Ishikawa, Osamu Nagano, Motohiro Takeda, Yoshihito Ujike, Takami Yamaguchi

EUROPEAN BIOPHYSICS JOURNAL WITH BIOPHYSICS LETTERS　41　(6)　571-578　2012/06

DOI： 10.1007/s00249-012-0811-y 　

ISSN： 0175-7571
Deposition of micrometer particles in pulmonary airways during inhalation and breath holding Peer-reviewed

Yohsuke Imai, Takahito Miki, Takuji Ishikawa, Takayuki Aoki, Takami Yamaguchi

JOURNAL OF BIOMECHANICS　45　(10)　1809-1815　2012/06

DOI： 10.1016/j.jbiomech.2012.04.017 　

ISSN： 0021-9290

eISSN： 1873-2380
Energy efficiency in collective motions of swimming bacteria

T. Ishikawa, N. Yoshida, H. Ueno, M. Wiedeman, Y. Imai, T. Yamaguchi

World Cong. Med. Phys. Biomed. Eng　CD-ROM, TH.07/05.1-5　2012/05/20
Computational biomechanics of physiological flow

T. Yamaguchi, T. Ishikawa, Y. Imai, H. Ueno, K. Numayama-Tsuruta, T. Omori

Biological Flow: A Conference to Celebrate the 70th Birthday of Timothy J. Padley FRS　38　2012/03/20
Rheology of a dilute suspention of red blood cells in simple shear flow

T. Omori, T. Ishikawa, Y. Imai, T. Yamaguchi

Proc. 18th International Symposium of Tohoku University Global COE Program　153-154　2012/03/20
Effect of constitutive law on the lateral migration of a capsule near a wall

S. Nix, Y. Imai, D. Matsunaga, T. Ishikawa, T. Yamaguchi

Proc. 18th International Symposium of Tohoku University Global COE Program　145-146　2012/03/20
Hydrodynamic entrapment of ciliates at the interface fluid-air

J. Ferracci, T. Ishikawa, H. Ueno, K. Numayama, Y. Imai, T. Yamaguchi

Proc. 18th International Symposium of Tohoku University Global COE Program　115-116　2012/03/20
Quantifying characteristics of blood cell at dense cellullar flow

D. Alizadehrad, Y. Imai, T. Ishikawa, T. Yamaguchi

Proc. 18th International Symposium of Tohoku University Global COE Program　111-112　2012/03/20
Collective Diffusion of red blood cells from high concentration to low

C. Chuang, T. Ishikawa, H. Ueno, K. Numayama, Y. Imai, T. Yamaguchi

Proc. 18th International Symposium of Tohoku University Global COE Program　109-110　2012/03/20
A particle model of cellular flow in microcirculation

T. Yamaguchi, T. Ishikawa, Y. Imai

Proc. 18th International Symposium of Tohoku University Global COE Program　61-64　2012/03/20
Radial dispersion of tracer particles through high-hematocrit blood flow within a capillary tube Invited

M. Saadatmand, T. Ishikawa, N. Matsuki, H. J. Abdekhodaie, Y. Imai, H. Ueno, T. Yamaguchi

Nano-Biomedical Engineering, Imperial College Press　134-143　2012/03/01
Behavior of a spherical capsule in simple shear flow near an infinite plane Invited

S. Nix, Y. Imai, D. Matsunaga, T. Ishikawa, T. Yamaguchi

Nano-Biomedical Engineering, Imperial College Press　122-127　2012/03/01
Entrapment of fresh water ciliates at the interface fluid-air Invited

J. Ferracci, T. Ishikawa, H. Ueno, K. Numayama-Tsuruta, Y. Imai, T. Yamaguchi

Nano-Biomedical Engineering, Imperial College Press　70-76　2012/03/01
Gradient diffusion of red blood cells flowing in a straight microchannel Invited

C. Chuang, T. Ishikawa, H. Ueno, K. Numayama-Tsuruta, Y. Imai, T. Yamaguchi

Nano-Biomedical Engineering, Imperial College Press　63-69　2012/03/01
Computational biomechanics of blood flow at macro- and micro-scales Invited

T. Yamaguchi, T. Ishikawa, Y. Imai

Nano-Biomedical Engineering, Imperial College Press　53-62　2012/03/01
Parallel simulation of cellular flow in microvessels using a particle method Peer-reviewed

Davod Alizadehrad, Yohsuke Imai, Keita Nakaaki, Takuji Ishikawa, Takami Yamaguchi

Journal of Biomechanical Science and Engineering　7　(1)　57-71　2012/02/29

DOI： 10.1299/jbse.7.57 　

ISSN： 1880-9863
Inertial migration of cancer cells in blood flow in microchannels Peer-reviewed

Tatsuya Tanaka, Takuji Ishikawa, Keiko Numayama-Tsuruta, Yohsuke Imai, Hironori Ueno, Takefumi Yoshimoto, Noriaki Matsuki, Takami Yamaguchi

BIOMEDICAL MICRODEVICES　14　(1)　25-33　2012/02

DOI： 10.1007/s10544-011-9582-y 　

ISSN： 1387-2176
Micro-flow visualization of magnetic nanoparticles for biomedical applications Peer-reviewed

R. Lima, R. J. Joseyphus, T. Ishikawa, Y. Imai, T. Yamaguchi

Single and Two-Phase Flows on Chemical and Biomedical Engineering　600-612　2012
Publisher: Bentham Science Publishers Ltd.
DOI： 10.2174/978160805295011201010600 　
Blood flow behavior in microchannels: Past, current and future trends Peer-reviewed

R. Lima, T. Ishikawa, Y. Imai, T. Yamaguchi

Single and Two-Phase Flows on Chemical and Biomedical Engineering　513-547　2012
Publisher: Bentham Science Publishers Ltd.
DOI： 10.2174/978160805295011201010513 　
Boundary element analysis of the multi-capsule flow using an ultra-high speed GPGPU computation Peer-reviewed

D. Matsunaga, Y. Imai, T. Ishikawa, T. Yamaguchi

WIT Transactions on Modelling and Simulation　53　201-208　2012

DOI： 10.2495/BE120181 　

ISSN： 1743-355X
Boundary element analysis of deformation and movement of a capsule and a red blood cell close to the wall Peer-reviewed

S. Nix, Y. Imai, T. Ishikawa, T. Yamaguchi

WIT Transactions on Modelling and Simulation　53　191-199　2012

DOI： 10.2495/BE120171 　

ISSN： 1743-355X
Flow visualization of trace particles and Red Blood Cells in a microchannel with a diverging and converging bifurcation Peer-reviewed

V. Leble, C. Fernandes, R. Dias, R. Lima, T. Ishikawa, Y. Imai, T. Yamaguchi

COMPUTATIONAL VISION AND MEDICAL IMAGE PROCESSING: VIPIMAGE 2011　209-211　2012
Flow of Red Blood Cells through a microfluidic extensional device: An image analysis assessment Peer-reviewed

T. Yaginuma, A. I. Pereira, P. J. Rodrigues, R. Lima, M. S. N. Oliveira, T. Ishikawa, T. Yamaguchi

COMPUTATIONAL VISION AND MEDICAL IMAGE PROCESSING: VIPIMAGE 2011　217-220　2012
Boundary element analysis of deformation and movement of a capsule and a red blood cell close to the wall

S. Nix, Y. Imai, T. Ishikawa, T. Yamaguchi

BOUNDARY ELEMENTS AND OTHER MESH REDUCTION METHODS XXXIV　53　191-199　2012

DOI： 10.2495/BE120171 　

ISSN： 1746-4064
Boundary element analysis of the multi-capsule flow using an ultra-high speed GPGPU computation

D. Matsunaga, Y. Imai, T. Ishikawa, T. Yamaguchi

BOUNDARY ELEMENTS AND OTHER MESH REDUCTION METHODS XXXIV　53　201-208　2012

DOI： 10.2495/BE120181 　

ISSN： 1746-4064
Patient-specific modelling of pulmonary airflow using GPU cluster for the application in medical practice Peer-reviewed

T. Miki, X. Wang, T. Aoki, Y. Imai, T. Ishikawa, K. Takase, T. Yamaguchi

COMPUTER METHODS IN BIOMECHANICS AND BIOMEDICAL ENGINEERING　15　(7)　771-778　2012

DOI： 10.1080/10255842.2011.560842 　

ISSN： 1025-5842
GPU computing for patient-specific model of pulmonary airflow

T. Yamaguchi, Y. Imai, T. Miki, T. Ishikawa

COMPUTATIONAL MODELLING OF OBJECTS REPRESENTED IN IMAGES: FUNDAMENTALS, METHODS AND APPLICATIONS III　239-242　2012
Separation of cancer cells from a red blood cell suspension using inertial force Peer-reviewed

Tatsuya Tanaka, Takuji Ishikawa, Keiko Numayama-Tsuruta, Yohsuke Imai, Hironori Ueno, Noriaki Matsuki, Takami Yamaguchi

LAB ON A CHIP　12　(21)　4336-4343　2012

DOI： 10.1039/c2lc40354d 　

ISSN： 1473-0197

eISSN： 1473-0189
Asymmetry of red blood cell motions in a microchannel with a diverging and converging bifurcation Peer-reviewed

Vladimir Leble, Rui Lima, Ricardo Dias, Carla Fernandes, Takuji Ishikawa, Yohsuke Imai, Takami Yamaguchi

BIOMICROFLUIDICS　5　(4)　044120　2011/12

DOI： 10.1063/1.3672689 　

ISSN： 1932-1058
GPU-based simulation of blood flow in complex microvessels Peer-reviewed

K. Nakaaki, Y. Imai, T. Ishikawa, C. T. Lim, T. Yamaguchi

5th East Asian Pacific Student Workshop on Nano-Biomedical Engineering　152-153　2011/11/20
A numerical computation on gastric mixing using GPU Peer-reviewed

I. Kobayashi, Y. Imai, S. Ishida, T. Ishikawa, T. Yamaguchi

5th East Asian Pacific Student Workshop on Nano-Biomedical Engineering　150-151　2011/11/20
Inertial migration of cancer cells in high hematocrit blood flow Peer-reviewed

T. Tanaka, T. Ishikawa, K. Numayama-Tsuruta, Y. Imai, H. Ueno, N. Matsuki, T. Yamaguchi

5th East Asian Pacific Student Workshop on Nano-Biomedical Engineering　146-147　2011/11/20
Entrapment of fresh water ciliates at the interface fluid-air Peer-reviewed

J. Ferracci, T. Ishikawa, H. Ueno, K. Numayama-Tsuruta, Y. Imai, T. Yamaguchi

5th East Asian Pacific Student Workshop on Nano-Biomedical Engineering　120-121　2011/11/20
Computation of near-wall capsule flow using boundary integral method Peer-reviewed

S. Nix, Y. Imai, D. Matsunaga, T. Ishikawa, T. Yamaguchi

5th East Asian Pacific Student Workshop on Nano-Biomedical Engineering　76-77　2011/11/20
Multi-GPU computing of capsule flow using boundary integral method Peer-reviewed

D. Matsunaga, Y. Imai, T. Omori, T. Ishikawa, T. Yamaguchi

5th East Asian Pacific Student Workshop on Nano-Biomedical Engineering　72-73　2011/11/20
Transport phenomena in suspensions of swimming microorganisms Peer-reviewed

T. Ishikawa

5th East Asian Pacific Student Workshop on Nano-Biomedical Engineering　50-51　2011/11/20
Analysis of fluid flow on the surface of tracheal lumen through effective ciliary motion Peer-reviewed

K. Kiyota, H. Ueno, T. Ishikawa, K. Numayama-Tsuruta, Y. Imai, N. Matsuki, T. Yamaguchi

5th East Asian Pacific Student Workshop on Nano-Biomedical Engineering　34-35　2011/11/20
Collective diffusion of red blood cells from high concentration to low Peer-reviewed

C. Chuang, T. Ishikawa, H. Ueno, K. Numayama-Tsuruta, Y. Imai, T. Yamaguchi

5th East Asian Pacific Student Workshop on Nano-Biomedical Engineering　32-33　2011/11/20
Development of a micro fluidic device to separate motile bacteria Peer-reviewed

T. Shioiri, T. Ishikawa, K. Numayama-Tsuruta, H. Ueno, Y. Imai, T. Yamaguchi

5th East Asian Pacific Student Workshop on Nano-Biomedical Engineering　12-13　2011/11/20
Development of GPU computing for simulating dense suspension of capsules Peer-reviewed

Y. Imai, D. Matsunaga, T. Ishikawa, T. Yamaguchi

5th Shanghai Int. Conf. Biophysics and Molecular Biology Abstract Book　125　2011/11/10
Analysis of ciliary motion and the axonemal structure in the mouse respiratory cilia Peer-reviewed

H. Ueno, T. Ishikawa, K. H. Bui, K. Gonda, T. Ishikawa, T. Yamaguchi

5th Shanghai Int. Conf. Biophysics and Molecular Biology Abstract Book　119　2011/11/10
Energy Transport in a Concentrated Suspension of Bacteria Peer-reviewed

T. Ishikawa, N. Yoshida, H. Ueno, M. Wiedeman, Y. Imai, T. Yamaguchi

Bulletin of the American Physical Society, DFD 2011　56　388　2011/11/03
Instabilities and global order in concentrated suspensions of spherical microswimmers Peer-reviewed

A. Evans, T. Ishikawa, T. Yamaguchi, E. Lauga

Bulletin of the American Physical Society, DFD 2011　56　387　2011/11/03
Orientational order in concentrated suspensions of spherical microswimmers Peer-reviewed

Arthur A. Evans, Takuji Ishikawa, Takami Yamaguchi, Eric Lauga

PHYSICS OF FLUIDS　23　(11)　111702　2011/11

DOI： 10.1063/1.3660268 　

ISSN： 1070-6631
Modelling of red blood cell motion and deformation using particle based method Peer-reviewed

T. Yamaguchi, Y. Imai, T. Ishikawa

Proc. ECCOMAS SIMBIO 2011　CD-ROM　2011/09/02
Swallowing simulation based on videofluorography Peer-reviewed

S. Ishida, Y. Imai, T. Ishikawa, A. Kinjyo, N. Matsuki, T. Yamaguchi

The International Conference on BioTribology Conference Abstracts　CD-ROM　2011/09/01
Particle based simulation of the microvascular blood flow in the malaria infection Peer-reviewed

T. Yamaguchi, Y. Imai, T. Ishikawa

Trends & Challenges in Computational Mechanics Program and Abstracts　43-44　2011/08/02
Particle based modeling and simulation of the red blood cell infected by malaria -mechanism of the margination of the infected red blood cell- Peer-reviewed

T. Yamaguchi, T. Ishikawa, Y. Imai

3rd Micro and Nano Flows Conference　CD-ROM MNF2011-87　2011/08/01
Computational Mechanics of Suspensions of Swimming Micro-organisms Peer-reviewed

Takuji Ishikawa

Proc. 11th U.S. Nat. Cong. Comp. Mech.　CD-ROM 213904　2011/07/01
Suspension biomechanics of swimming micro-organisms Peer-reviewed

Takuji Ishikawa

Proc. 21st Int. Offshore Polar Eng. Conf.　235-238　2011/06/02
Development of a microfluidic device for partial cell separation

R. Lima, M. S. N. Oliveira, T. Yaginuma, T. Ishikawa, Y. Imai, T. Yamaguchi

Proc. Japan-Portugal Nano-BME Symp.　49-50　2011/06/01
Motions of trace particles and red blood cells in a PDMS microchannel with a converging bifurcation

V. Leble, R. Dias, R. Lima, C. Fernandes, T. Ishikawa, Y. Imai, T. Yamaguchi

Proc. Japan-Portugal Nano-BME Symp.　29-30　2011/06/01
High performance GPU computing of capsule flow using boundary integral method

D. Matsunaga, Y. Imai, T. Omori, T. Miki, T. Ishikawa, T. Yamaguchi

Proc. Japan-Portugal Nano-BME Symp.　19-22　2011/06/01
Gradient diffusion of red blood cells in a Y-shape microchannel

C.-H. Chuang, T. Ishikawa, K. Numayama-Tsuruta, Y. Imai, T. Yamaguchi

Proc. Japan-Portugal Nano-BME Symp.　17-18　2011/06/01
Numerical simulation of cell depleted peripheral layer and red blood cells motion in microvascular blood flow

D. Alizadehrad, Y. Imai, T. Ishikawa, T. Yamaguchi

Proc. Japan-Portugal Nano-BME Symp.　15-16　2011/06/01
Analysis of ciliary motion and fluid flow on the surface of tracheal cells

H. Ueno, T. Ishikawa, K. Gonda, K. H. Bui, T. Ishikawa, Y. Imai, K. Numayama-Tsuruta, T. Yamaguchi

Proc. Japan-Portugal Nano-BME Symp.　11-14　2011/06/01
Numerical simulation on margination of malaria-infected red blood cells in microvessels

Y. Imai, K. Nakaaki, T. Ishikawa, T. Yamaguchi

Proc. Japan-Portugal Nano-BME Symp.　7-10　2011/06/01
Computational biomechanics for respiratory and micro-circulation systems

T. Yamaguchi, T. Ishikawa, Y. Imai

Proc. Japan-Portugal Nano-BME Symp.　1-4　2011/06/01
Transport phenomena of microbial flora in the small intestine with peristalsis Peer-reviewed

T. Ishikawa, T. Sato, G. Mohit, Y. Imai, T. Yamaguchi

JOURNAL OF THEORETICAL BIOLOGY　279　(1)　63-73　2011/06

DOI： 10.1016/j.jtbi.2011.03.026 　

ISSN： 0022-5193
Computational analysis of the margination of malaria-infected red blood cells in microcirculation

T. Yamaguchi, T. Ishikawa, Y. Imai

Microscale Modeling in Biomechanics and Mechanobiology Program and Abstract　2011/05
Effect of red blood cells on dynamics of microvascular blood flow

D. Alizadehrad, Y. Imai, T. Ishikawa, T. Yamaguchi

Microscale Modeling in Biomechanics and Mechanobiology Program and Abstract　2011/05
Capsule flow analysis using GPU computation

D. Matsunaga, Y. Imai, T. Omori, T. Miki, T. Ishikawa, T. Yamaguchi

Microscale Modeling in Biomechanics and Mechanobiology Program and Abstract　2011/05
Diffusion of red blood cells from high concentration to low in a blood flow microchannel

C. Chugang, T. Ishikawa, K. Numayama, Y. Imai, H. Ueno, T. Yamaguchi

Microscale Modeling in Biomechanics and Mechanobiology Program and Abstract　2011/05
Margination of red blood cells infected by Plasmodium falciparum due to local increase in hematocrit Peer-reviewed

Y. Imai, K. Nakaaki, H. Kondo, T. Ishikawa, C. T. Lim, T. Yamaguchi

Journal of Biomechanics　44　1553-1558　2011/05/01

DOI： 10.1016/j.jbiomech.2011.02.084 　
Comparison between spring network models and continuum constitutive laws: Application to the large deformation of a capsule in shear flow Peer-reviewed

T. Omori, T. Ishikawa, D. Barthes-Biesel, A. -V. Salsac, J. Walter, Y. Imai, T. Yamaguchi

PHYSICAL REVIEW E　83　(4)　041918　2011/04

DOI： 10.1103/PhysRevE.83.041918 　

ISSN： 1539-3755
Novel methods for the computational biomechanics study of respiratory and micro-circulatory systems

T. Yamaguchi, T. Ishikawa, Y. Imai

16th International Symposium of Tohoku University Global COE Program, Global Nano-Biomedical Engineering Education and Research Network Centre, Nano-Biomedical Engineering in the East Asian-Pacific Rim Region　99-102　2011/03
A fourth-order Cartesian local mesh refinement method for the computational fluid dynamics of physiological flow in multi-generation branched vessels Peer-reviewed

Takahito Miki, Yohsuke Imai, Takuji Ishikawa, Shigeo Wada, Takayuki Aoki, Takami Yamaguchi

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING　27　(3)　424-435　2011/03

DOI： 10.1002/cnm.1416 　

ISSN： 2040-7939
Asymmetry of blood flow and cancer cell adhesion in a microchannel with symmetric bifurcation and confluence Peer-reviewed

Takuji Ishikawa, Hiroki Fujiwara, Noriaki Matsuki, Takefumi Yoshimoto, Yohsuke Imai, Hironori Ueno, Takami Yamaguchi

BIOMEDICAL MICRODEVICES　13　(1)　159-167　2011/02

DOI： 10.1007/s10544-010-9481-7 　

ISSN： 1387-2176
Preface Peer-reviewed

Takuji Ishikawa

Journal of Biomechanical Science and Engineering　6　(2)　63-63　2011

DOI： 10.1299/jbse.6.63 　

ISSN： 1880-9863
Red Blood Cell Deformation in flows through a PDMS Hyperbolic Microchannel Peer-reviewed

T. Yaginuma, M. S. N. Oliveira, R. Lima, T. Ishikawa, T. Yamaguchi

NANOTECHNOLOGY 2011: ELECTRONICS, DEVICES, FABRICATION, MEMS, FLUIDICS AND COMPUTATIONAL, NSTI-NANOTECH 2011, VOL 2　505-507　2011
Microscale Flow Dynamics of Red Blood Cells in Microchannels: An Experimental and Numerical Analysis

R. Lima, C. S. Fernandes, R. Dias, T. Ishikawa, Y. Imai, T. Yamaguchi

COMPUTATIONAL VISION AND MEDICAL IMAGE PROCESSING: RECENT TRENDS　19　297-309　2011

DOI： 10.1007/978-94-007-0011-6_17 　
Development of a microdevice for sorting motile bacteria Peer-reviewed

T. Shioiri, T. Ishikawa, K. Numayama-Tsuruta, Y. Imai, H. Ueno, T. Yamaguchi

ASME 2011 6th Frontiers in Biomedical Devices Conference and Exhibition, BioMed 2011　25-26　2011

DOI： 10.1115/BioMed2011-66035 　
Collection of cancer cells from blood samples using inertial migration forces Peer-reviewed

T. Tanaka, T. Ishikawa, K. Numayama-Tsuruta, Y. Imai, H. Ueno, N. Matsuki, T. Yamaguchi

ASME 2011 6th Frontiers in Biomedical Devices Conference and Exhibition, BioMed 2011　13-14　2011

DOI： 10.1115/BioMed2011-66034 　
Fluid particle diffusion through high-hematocrit blood flow within a capillary tube Peer-reviewed

Maryam Saadatmand, Takuji Ishikawa, Noriaki Matsuki, Mohammad Jafar Abdekhodaie, Yohsuke Imai, Hironori Ueno, Takami Yamaguchi

JOURNAL OF BIOMECHANICS　44　(1)　170-175　2011/01

DOI： 10.1016/j.jbiomech.2010.09.004 　

ISSN： 0021-9290
DEVELOPMENT OF A PARTICLE INTERACTION KERNEL FOR CONVECTION-DIFFUSION SCALAR TRANSPORT EQUATION Peer-reviewed

Chinlong Huang, Tony W. H. Sheu, Takuji Ishikawa, Takami Yamaguchi

NUMERICAL HEAT TRANSFER PART B-FUNDAMENTALS　60　(2)　96-115　2011

DOI： 10.1080/10407790.2011.594389 　

ISSN： 1040-7790
Computational study on effect of stenosis on primary thrombus formation Peer-reviewed

Hiroki Kamada, Ken-ichi Tsubota, Masanori Nakamura, Shigeo Wada, Takuji Ishikawa, Takami Yamaguchi

BIORHEOLOGY　48　(2)　99-114　2011

DOI： 10.3233/BIR-2011-0585 　

ISSN： 0006-355X
Large-scale numerical simulation of blood flow in microvessels

D. Alizadehrad, Y. Imai, T. Ishikawa, T. Yamaguchi

Proc. 4th East Asian Pacific Stu. Workshop Nano-Biomed. Eng.　98-99　2010/12
Hydrodynamic interaction of two unsteady squirmers

T. Ishikawa, D. Giacche

Bulletin of the American Physical Society, DFD 2010　55　94　2010/11/21
Designing a clinical education program for engineers: The ESTEEM Project Peer-reviewed

Noriaki Matsuki, Motohiro Takeda, Masahiro Yamano, Yohsuke Imai, Takuji Ishikawa, Takami Yamaguchi

JOURNAL OF INTERPROFESSIONAL CARE　24　(6)　738-741　2010/11

DOI： 10.3109/13561820903564714 　

ISSN： 1356-1820
Hydrodynamic interaction of two unsteady model microorganisms Peer-reviewed

Davide Giacche, Takuji Ishikawa

JOURNAL OF THEORETICAL BIOLOGY　267　(2)　252-263　2010/11

DOI： 10.1016/j.jtbi.2010.08.003 　

ISSN： 0022-5193
Hydrodynamic entrapment of bacteria swimming near a solid surface Peer-reviewed

Davide Giacche, Takuji Ishikawa, Takami Yamaguchi

PHYSICAL REVIEW E　82　(5)　056309　2010/11

DOI： 10.1103/PhysRevE.82.056309 　

ISSN： 1539-3755
Particle method computation of the red blood cell motion in malaria infection

T. Yamaguchi, Y. Imai, T. Ishikawa

International Conference on Numerical Analysis and Applied Mathematics 2010 (CD-ROM)　2010/09

DOI： 10.1063/1.3498545 　
Fluid particle diffusion in a semi-dilute suspension of model micro-organisms Peer-reviewed

T. Ishikawa, J. T. Locsei, T. J. Pedley

Physical Review E　82　021408　2010/09/01
Separation of cancer cells from blood by using a micro fluidic device

T. Tanaka, T. Ishikawa, N. Matsuki, Y. Imai, H. Ueno, K. N-Tsuruta, T. Yamaguchi

KIST-Tohoku Joint Symp. Nanobiomed. Eng.　75-76　2010/08/02
Effects of rosette formation and cytoadhesion on hemodynamics in malaria infection

K. Nakaaki, Y. Imai, H. Kondo, T. Ishikawa, C. T. Lim, T. Yamaguchi

KIST-Tohoku Joint Symp. Nanobiomed. Eng.　67-68　2010/08/02
Suspension biomechanics of swimming micro-organisms

T. Ishikawa

KIST-Tohoku Joint Symp. Nanobiomed. Eng.　27-28　2010/08/02
A numerical study on migration of malaria infected red blood cells Invited

Y. Imai, K. Nakaaki, H. Kondo, T. Ishikawa, C. T. Lim, T. Yamaguchi

KIST-Tohoku Joint Symp. Nanobiomed. Eng.　15-16　2010/08/02
Measurement of the Red Blood Cell (RBC) Dispersion in Microchannels: The Effect of the Temperature

D. Pinho, A. Pereira, R. Lima, T. Ishikawa, Y. Imai, T. Yamaguchi

IFMBE Proceedings　31　1067-1070　2010/08/01
Numerical Modeling of Microvascular Hemodynamics in Plasmodium Falciparum Malaria

Y. Imai, K. Nakaaki, H. Kondo, T. Ishikawa, C. T. Lim, T. Yamaguchi

IFMBE Proceedings　31　1145-1148　2010/08/01

DOI： 10.1007/978-3-642-14515-5_291 　
Micro-flow Visualization of in vitro Blood through a Microchannel with a Bifurcation and Confluence

R. Lima, M. Oliveira, T. Ishikawa, N. Matsuki, Y. Imai, T. Yamaguchi

6th World Congress of Biomechanics Abstracts　561　2010/08/01
Measuring the Cell-Free Layer in circular Microchannels

C. Fidalgo, A. Sa, R. Lima, M. Oliveira, T. Ishikawa, Y. Imai, T. Yamaguchi

6th World Congress of Biomechanics Abstracts　472　2010/08/01
A Numerical Study on Fluid Motion in the Stomach

I. Kobayashi, Y. Imai, S. Ishida, T. Ishikawa, T. Yamaguchi

6th World Congress of Biomechanics Abstracts　575　2010/08/01
Parallel 3-D Code to Investigate the Pathophysiology of Malaria on Distributed Memory Systems

D. Alizadehrad, Y. Imai, T. Ishikawa, T. Yamaguchi

6th World Congress of Biomechanics Abstracts　581　2010/08/01
Diffusion of Fluid Particles in High Hematocrit Blood Flow in a Capillary Tube

M. Saadatmand, T. Ishikawa, N. Matsuki, M. J. Abdekhodaie, Y. Imai, H. Ueno, T. Yamaguchi

6th World Congress of Biomechanics Abstracts　471　2010/08/01
Analysis of Swallowing Motion based on Videofluorography

S. Ishida, Y. Imai, A. Kinjo, N. Matsuki, T. Ishikawa, T. Yamaguchi

6th World Congress of Biomechanics Abstracts　165　2010/08/01
A Numerical Study on the Behavior of Cells in Micro-scale Blood Flows

Y. Matsumoto, Y. Imai, T. Ishikawa, T. Yamaguchi

6th World Congress of Biomechanics Abstracts　471　2010/08/01
Effect of Membrane Modeling on the Capsule Deformation: Comparison between a Spring Network and Continuum Models

T. Omori, T. Ishikawa, D. Barthes-Biesel, A.-V. Salsac, Y. Imai, T. Yamaguchi

6th World Congress of Biomechanics Abstracts　470　2010/08/01
Development of a Micro Fluidic Device to Separate Cancer Cells from Blood

T. Tanaka, T. Ishikawa, N. Matsuki, Y. Imai, H. Ueno, T. Yamaguchi

6th World Congress of Biomechanics Abstracts　164　2010/08/01
Effect of Adhesive Properties of Malaria-infected Red Blood Cells in Microcirculation

K. Nakaaki, Y. Imai, H. Kondo, T. Ishikawa, C. T. Lim, T. Yamaguchi

6th World Congress of Biomechanics Abstracts　503　2010/08/01
Stable Swimming of Bacteria near a Flat Wall

D. Giacche, T. Ishikawa, T. Yamaguchi

6th World Congress of Biomechanics Abstracts　176　2010/08/01
Hydrodynamic entrapment of bacteria swimming near a solid wall

T. Ishikawa, D. Giacche, T. Yamaguchi

Individual and Collective Fluid Mechanics of Swimming Microorganisms, Talk and poster abstracts, p.6　2010/07

DOI： 10.1103/PhysRevE.82.056309 　
Blood flow and cancer cell adhesion in a microchannel with bifurcation and confluence

T. Ishikawa, H. Fujiwara, N. Matsuki, T. Yoshimoto, Y. Imai, H. Ueno, T. Yamaguchi

17th Congress of the European Society of Biomechanics, ESB2010 Abstracts CD-ROM　2010/07
Confocal micro-flow visualization of blood cells

R. Lima, T. Ishikawa, Y. Imai, T. Yamaguchi

CFD2010 Proceedings (CD-ROM)　2010/06
Efficient parallel code for simulating malaria infected blood flow

D. Alizadehrad, Y. Imai, T. Ishikawa, T. Yamaguchi

22nd International Conference on Parallel Computational Fluid Dynamics (ParCFD 2010) (CD-ROM)　2010/05
Impact of membrane modeling in analysing deformation of a capsule:comparison between a spring network model and constitutive laws

T. Omori, T. Ishikawa, D. Barthes-biesel, A. V. Salsac, Y. Imai, T. Yamaguchi

Proc. 4th Euro. Conf. Comp. Mech., CD-ROM No.781　2010/05
Hydrodynamic entrapment of bacteria near a solid surface

D. Giacche, T. Ishikawa, T. Yamaguchi

Proc. 4th Euro. Conf. Comp. Mech., CD-ROM No.411　2010/05
Numerical simulation of interaction among malaria-infected red blood cells, healthy red blood cells, and endothelial cells

Y. Imai, K. Nakaaki, H. Kondo, T. Ishikawa, C. T. Lim, T. Yamaguchi

Proc. 4th Euro. Conf. Comp. Mech., CD-ROM No.269　2010/05
Activation of caspases and apoptosis in response to low-voltage electric pulses Peer-reviewed

Noriaki Matsuki, Motohiro Takeda, Takuji Ishikawa, Aki Kinjo, Tomoaki Hayasaka, Yohsuke Imai, Takami Yamaguchi

Oncology Reports　23　(5)　1425-1433　2010/05

DOI： 10.3892/or-00000780 　

ISSN： 1021-335X 1791-2431
Modeling of hemodynamics arising from malaria infection Peer-reviewed

Yohsuke Imai, Hitoshi Kondo, Takuji Ishikawa, Chwee Teck Lim, Takami Yamaguchi

JOURNAL OF BIOMECHANICS　43　(7)　1386-1393　2010/05

DOI： 10.1016/j.jbiomech.2010.01.011 　

ISSN： 0021-9290
Effect of pneumothorax on morphology and hemodynamic of pulmonary artery

J-J. Christophe, T. Ishikawa, N. Matsuki, Y. Imai, K. Takase, M. Thiriet, T. Yamaguchi

11th International Symposium of Tohoku University Global COE Program, Global Nano-Biomedical Engineering Education and Research Network Centre, Nano-Biomedical Engineering in the East Asian-Pacific Rim Region　103-104　2010/03
Numerical investigation of bacteria swimming near a solid surface

D. Giacche, T. Ishikawa, T. Yamaguchi

11th International Symposium of Tohoku University Global COE Program, Global Nano-Biomedical Engineering Education and Research Network Centre, Nano-Biomedical Engineering in the East Asian-Pacific Rim Region　105-106　2010/03
Radial dispersion of tracer particles in blood flow in a capillary tube

M. Saadatmand, T. Ishikawa, N. Matsuki, M. J. Abdekhodaie, Y. Imai, H. Ueno, T. Yamaguchi

11th International Symposium of Tohoku University Global COE Program, Global Nano-Biomedical Engineering Education and Research Network Centre, Nano-Biomedical Engineering in the East Asian-Pacific Rim Region　113-114　2010/03
Comprehensive application of particle methods to the diseases of the blood

T. Yamaguchi, Y. Imai, H. Kamada, K. Nakaaki, T. Ishikawa

The 2nd Biosupercomputing symposium　118-119　2010/03
A three-dimensional particle simulation of the formation and collapse of a primary thrombus Peer-reviewed

Hiroki Kamada, Ken-ichi Tsubota, Masanori Nakamura, Shigeo Wada, Takuji Ishikawa, Takami Yamaguchi

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING　26　(3-4)　488-500　2010/03

DOI： 10.1002/cnm.1367 　

ISSN： 2040-7939
ATP Transport in Saccular Cerebral Aneurysms at Arterial Bends Peer-reviewed

Yohsuke Imai, Kodai Sato, Takuji Ishikawa, Andrew Comerford, Tim David, Takami Yamaguchi

ANNALS OF BIOMEDICAL ENGINEERING　38　(3)　927-934　2010/03

DOI： 10.1007/s10439-009-9864-1 　

ISSN： 0090-6964
Computational biomechanics for investigating cardiovascular diseases

T. Yamaguchi, H. Kondo, Y. Shimogonya, Y. Imai, N. Matsuki, T. Ishikawa

Nano-Biomedical Engineering 2009　41-50　2010/02/25
Red Blood Cell Dispersion in 100 mu m Glass Capillaries: The Temperature Effect Peer-reviewed

D. Pinho, A. Pereira, R. Lima, T. Ishikawa, Y. Imai, T. Yamaguchi

6TH WORLD CONGRESS OF BIOMECHANICS (WCB 2010), PTS 1-3　31　1067-+　2010

ISSN： 1680-0737
Cellular behaviours in high hematocrit blood flow in micro-channels

T. Ishikawa, N. Matsuki, Y. Imai, H. Ueno, T. Yamaguchi

SMART-Tohoku GCOE joint Workshop on Micro & Nano Bioenginering, p.50　2010/01
Patient-specific morphological and blood flow analysis of pulmonary artery in the case of severe deformations of the lung due to pneumothorax Peer-reviewed

Jean-Joseph Christophe, Takuji Ishikawa, Noriaki Matsuki, Yohsuke Imai, Kei Takase, Marc Thiriet, Takami Yamaguchi

Journal of Biomechanical Science and Engineering　5　(5)　485-498　2010

DOI： 10.1299/jbse.5.485 　

ISSN： 1880-9863
Patient specific morphological and hemodynamic analysis of pulmonary artery in the case of severe deformations of the lung

J-J. Christophe, T. Ishikawa, N. Matsuki, Y. Imai, K. Takase, M. Thiriet, T. Yamaguchi

3rd East Asian Pacific Student Workshop on Nano-Biomedical Engineering, pp.124-125　2009/12
Impact of membrane modeling on the deformation analysis of a capsule

T. Oomori, T. Ishikawa, D. Barthes-Biesel, A. V. Salsac, Y. Imai, T. Yamaguchi

3rd East Asian Pacific Student Workshop on Nano-Biomedical Engineering, pp.122-123　2009/12
Development of a biologically inspired locomotion system for a capsule endoscope Peer-reviewed

Daisuke Hosokawa, Takuji Ishikawa, Hirohisa Morikawa, Yohsuke Imai, Takami Yamaguchi

INTERNATIONAL JOURNAL OF MEDICAL ROBOTICS AND COMPUTER ASSISTED SURGERY　5　(4)　471-478　2009/12

DOI： 10.1002/rcs.284 　

ISSN： 1478-5951
準希薄微生物溶液における自己拡散シミュレーション－せん断流れの影響－ Peer-reviewed

石川拓司

シミュレーション　1　60-65　2009/12/01

DOI： 10.11308/tjsst.1.60 　
Fluid flow analysis of the surface of tracheal ciliary cells

H. Ueno, K. Gonda, Y. Imai, N. Matsuki, T. Ishikawa, T. Yamaguchi

Dynein International Workshop 2009, p.11　2009/11
Shear-induced fluid-tracer diffusion in a semi-dilute suspension of spheres

T. Ishikawa, T. Yamaguchi

Bulletin of the American Physical Society, DFD 2009　54　293　2009/11
Simulation of saccular cerebral aneurysm formation based on GON indicator Peer-reviewed

Y. Shimogonya, T. Ishikawa, Y. Imai, N. Matsuki, T. Yamaguchi

International Journal of Computational Fluid Dynamics　23　583-593　2009/11/01

DOI： 10.1080/10618560902953575 　
Determination of the cell-free layer in circular PDMS microchannels

T. Cerdeira, F. Monteiro, R. Lima, M. Oliveira, T. Ishikawa, Y. Imai, T. Yamaguchi

Computational Vision and Medical Image Processing - VipIMAGE 2009, CRC press, pp.357-360　2009/10
Motions of particles and red blood cells in a bifurcation: comparison between experiments and numerical simulations

M. Lagoela, B. Oliveira, D. Cidre, C. Fernandes, C. Balsa, R. Lima, R. Dias, T. Ishikawa, Y. Imai, T. Yamaguchi

Computational Vision and Medical Image Processing - VipIMAGE 2009, CRC press, pp.339-342　2009/10
Patient-specific blood flow analysis of pulmonary artery affected by severe deformations of the lung

J-J. Christophe, T. Ishikawa, N. Matsuki, Y. Imai, K. Takase, M. Thiriet, T. Yamaguchi

Computational Vision and Medical Image Processing - VipIMAGE 2009, CRC press, pp.335-338　2009/10
Diffusion in concentrated suspensions of biological cells

T. Ishikawa

Computational Vision and Medical Image Processing - VipIMAGE 2009, CRC press, pp.327-330　2009/10
Suspension biomechanics of swimming microbes Peer-reviewed

Takuji Ishikawa

JOURNAL OF THE ROYAL SOCIETY INTERFACE　6　(39)　815-834　2009/10

DOI： 10.1098/rsif.2009.0223 　

ISSN： 1742-5689
Particle method simulation of red blood cells infected by malaria

T. Yamaguchi, Young Ho Kang, H. Kondo, Y. Imai, T. Ishikawa

Med. Phys. Biomed. Eng. World Cong. 2009, CD-ROM-131　2009/09
Simulation of microcirculatory disorder by malaria infection using a particle method

T. Yamaguchi, H. Kondo, Y. Imai, T. Ishikawa

Int. Cong. Computational Bioeng. (ICCB 2009), USB-83　2009/09
Simulation of rosette formation and destruction of malaria infected red blood cells Peer-reviewed

T. Yamaguchi, Y. Imai, T. Ishikawa

Book of Abstracts BIOENGINEERING 09, p.48　2009/09
On the sensitivity of a hemodynamic index for cerebral aneurysm initiation, the GON, to flow input waveform Peer-reviewed

Y. Shimogonya, T. Ishikawa, Y. Imai, N. Matsuki, T. Yamaguchi

Book of Abstracts BIOENGINEERING 09, p.126　2009/09
Pulmonary airflow simulation of inspiration and expiration using a patient-specific model Peer-reviewed

T. Miki, Y. Imai, T. Ishikawa, T. Yamaguchi

Book of Abstracts BIOENGINEERING 09, p.92　2009/09
Mixing of red blood cells in high hematocrit blood flow in micro-channels Peer-reviewed

T. Ishikawa, H. Fujiwara, R. Lima, N. Matsuki, Y. Imai, T. Yamaguchi

Proc. 3rd Switzerland-Japan Workshop on Biomechanics 2009, p.47　2009/09

DOI： 10.1016/j.jbiomech.2009.01.026 　
Axisymmetric polydimethysiloxane microchannels for in vitro hemodynamic studies Peer-reviewed

Rui Lima, Monica S. N. Oliveira, Takuji Ishikawa, Hirokazu Kaji, Shuji Tanaka, Matsuhiko Nishizawa, Takami Yamaguchi

BIOFABRICATION　1　(3)　035005　2009/09

DOI： 10.1088/1758-5082/1/3/035005 　

ISSN： 1758-5082
Fluid Particle Diffusion in a Semi-dilute Suspension of Model Micro-organisms

T. Ishikawa, J. T. Locsei, T. J. Pedley

The 4th International Symposium on Aero Aqua Bio-Mechanisms 2009, CD-ROM S01　2009/08
Measurement of Individual Red Blood Cell Motions Under High Hematocrit Conditions Using a Confocal Micro-PTV System Peer-reviewed

Rui Lima, Takuji Ishikawa, Yohsuke Imai, Motohiro Takeda, Shigeo Wada, Takami Yamaguchi

ANNALS OF BIOMEDICAL ENGINEERING　37　(8)　1546-1559　2009/08

DOI： 10.1007/s10439-009-9732-z 　

ISSN： 0090-6964
Computational biomechanics of malaria and arterial diseases Invited

T. Ishikawa

37th Int. Cong. Physiol. Sci.　PSJ II-7-4　2009/07/02
Development of an Ethernet-linked Wearable System for Monitoring EMG and Acceleration Peer-reviewed

M. Kishimoto, T. Yoshida, T. Hayasaka, D. Mori, Y. Imai, N. Matsuki, T. Ishikawa, T. Yamaguchi

Technology and Health Care　17　121-131　2009/07/01

DOI： 10.3233/THC-2009-0538 　
Rheology of Cancer Cells with Different Metastatic Properties

T. Yoshimoto, T.Ishikawa, N. Matsuki, H. Fujiwara, Y. Imai, H. Ueno, M. Takeda, T. Yamaguchi

Proc. ASME 2009 Summer Bioeng. Conf.　CD-ROM SBC2009-206593　2009/06/02

DOI： 10.1115/SBC2009-206593 　
A Numerical Model of Adhesion Property of Malaria Infected Red Blood Cells in Micro Scale Blood Flows

Y. Imai, H. Kondo, Y. H. Kang, T. Ishikawa, C. T. Lim, T. Yamaguchi

Proc. ASME 2009 Summer Bioeng. Conf.　CD-ROM SBC2009-206456　2009/06/02

DOI： 10.1115/SBC2009-206456 　
Morphology and Blood Flow Analysis of Pulmonary Arteries Under Respiratory Disorders

J.-J. Christophe, T. Ishikawa, Y. Imai, N. Matsuki, K. Takase, T. Yamaguchi

Proc. ASME 2009 Summer Bioeng. Conf.　CD-ROM SBC2009-206243　2009/06/02

DOI： 10.1115/SBC2009-206243 　
Individual Motions of Red Blood Cells in High-Hematocrit Blood Flowing in a Microchannel with Complex Geometries

T. Ishikawa, H. Fujiwara, N. Matsuki, R. Lima, Y. Imai, H. Ueno, T. Yamaguchi

Proc. ASME 2009 Summer Bioeng. Conf.　CD-ROM SBC2009-206462　2009/06/02

DOI： 10.1115/SBC2009-206462 　
Clinical Education for Engineers: ESTEEM Project

N.Matsuki, M.Takeda, M.Yamano, Y.Imai, T.Ishikawa, T. Yamaguchi

Proc. ASME 2009 Summer Bioeng. Conf.　CD-ROM SBC2009-206594　2009/06/02

DOI： 10.1115/SBC2009-206594 　
Effects of unique biomedical education programs for engineers: REDEEM and ESTEEM projects Peer-reviewed

Noriaki Matsuki, Motohiro Takeda, Masahiro Yamano, Yohsuke Imai, Takuji Ishikawa, Takami Yamaguchi

ADVANCES IN PHYSIOLOGY EDUCATION　33　(2)　91-97　2009/06

DOI： 10.1152/advan.90120.2008 　

ISSN： 1043-4046
Red blood cell motions in high-hematocrit blood flowing through a stenosed microchannel Peer-reviewed

H. Fujiwara, T. Ishikawa, R. Lima, N. Matsuki, Y. Imai, H. Kaji, M. Nishizawa, T. Yamaguchi

JOURNAL OF BIOMECHANICS　42　(7)　838-843　2009/05

DOI： 10.1016/j.jbiomech.2009.01.026 　

ISSN： 0021-9290
Effect of the membrane bending stiffness on the deformation of a red blood cell

T. Omori, T. Ishikawa, D. Birthes-Biesel, Y. Imai, T. Yamaguchi

Proc. AP Biomech 2009　196-197　2009/04/03
Numerical Simulation of Inpiratory and Expiratory Pulmonary Airflow using a Patient-specific Model

T. Miki, Y. Imai, T. Ishikawa, S. Wada, T. Yamaguchi

Proc. AP Biomech 2009　164-165　2009/04/03
Low voltage pulses can induce apoptosis

N. Matsuki, T. Ishikawa, Y. Imai, T. Yamaguchi

Proc. AP Biomech 2009　154-155　2009/04/03
Motion of individual red blood cells in a concentrated suspension flowing through micro-channels

T. Ishikawa, H. Fujiwara, N. Matsuki, R. Lima, Y. Imai, T. Yamaguchi

Proc. AP Biomech 2009　102-103　2009/04/03
A Micro Scale Blood Flow Model to Study Pathology of Malaria

Y. Imai, H. Kondo, Y. H. Kang, T. Ishikawa, C. T. Lim, T. Yamaguchi

Proc. AP Biomech 2009　100-101　2009/04/03
A numerical model to study hemodynamics arising from malaria infection

Y. Imai, H. Kondo, Y. H. Kang, T. Ishikawa, C. T. Lim, T. Yamaguchi

Proceedings of ICCES’09　96　2009/04/02
Motion of individual cells in high hematocrit blood flow in micro-channels Invited

T. Ishikawa, H. Fujiwara, N. Matsuki, R. Lima, Y. Imai, T. Yamaguchi

Proceedings of ICCES’09　244　2009/04/02
Computational biomechanics for investigating various diseases over micro to macro scales Invited

T. Yamaguchi, T. Ishikawa, Y. Imai

Proceedings of ICCES’09　10　2009/04/02
Modeling of the membrane bending rigidity for calculating red blood cell deformation

T. Omori, T. Ishikawa, D. Birthes-Biesel, Y. Imai, T. Yamaguchi

15th Int. Conf. Finite Elements in Flow Problems (FEF09) Abstracts　41　2009/04/01
Patient-specific pulmonary airflow simulation using cartestian adaptive mesh refinement method

T. Miki, Y. Imai, T. Ishikawa, S. Wada, T. Yamaguchi

15th Int. Conf. Finite Elements in Flow Problems (FEF09) Abstracts　37　2009/04/01
Hemodynamic Analysis of Microcirculation in Malaria Infection Peer-reviewed

Hitoshi Kondo, Yohsuke Imai, Takuji Ishikawa, Ken-ichi Tsubota, Takami Yamaguchi

ANNALS OF BIOMEDICAL ENGINEERING　37　(4)　702-709　2009/04

DOI： 10.1007/s10439-009-9641-1 　

ISSN： 0090-6964
Computational simulation of blood flow in pulmonary artery under respiratory disorders

J-J. Christophe, T. Ishikawa, Y. Imai, N. Matsuki, K. Takase, T. Yamaguchi

9th International Symposium of Tohoku University Global COE Program, Global Nano-Biomedical Engineering Education and Research Network Centre, Nano-Biomedical Engineering in the East Asian-Pacific Rim Region　100-101　2009/03
Can temporal fluctuation in spatial wall shear stress gradient initiate a cerebral aneurysm? A proposed novel hemodynamic index, the gradient oscillatory number (GON) Peer-reviewed

Yuji Shimogonya, Takuji Ishikawa, Yohsuke Imai, Noriaki Matsuki, Takami Yamaguchi

JOURNAL OF BIOMECHANICS　42　(4)　550-554　2009/03

DOI： 10.1016/j.jbiomech.2008.10.006 　

ISSN： 0021-9290
Fluid dynamics of a suspension of micro-organisms Invited

T. Ishikawa

Int. Comf. Nonlinear Sci. Abstracts　25　2009/02/01

DOI： 10.1007/978-3-540-92841-6_533 　
東北大学における「次世代医療関連産業中核人材育成のための実践的教育システム」の開発と実証研究 Peer-reviewed

山野真裕, 松木範明, 沼山恵子, 武田元博, 早坂智明, 石川拓司, 山口隆美

工学教育　57　13-21　2009/02/01

DOI： 10.4307/jsee.57.2_13 　
Microscale Flow Dynamics of Red Blood Cells in Microchannels: An Experimental and Numerical Analysis Invited Peer-reviewed

R. Lima, M. Nakamura, T. Omori, T. Ishikawa, S. Wada, T. Yamaguchi

Advances in Computational Vision and Medical Image Processing, Springer　13　203-220　2009/01/10
An internet-based wearable watch-over system for elderly and disabled utilizing EMG and accelerometer Peer-reviewed

M. Kishimoto, T. Yoshida, T. Hayasaka, D. Mori, Y. Imai, N. Matsuki, T. Ishikawa, T. Yamaguchi

Technology and Health Care　17　(2)　121-131　2009

DOI： 10.3233/THC-2009-0538 　

ISSN： 0928-7329
A realistic simulation of saccular cerebral aneurysm formation: focussing on a novel haemodynamic index, the gradient oscillatory number Peer-reviewed

Y. Shimogonya, T. Ishikawa, Y. Imai, N. Matsuki, T. Yamaguchi

INTERNATIONAL JOURNAL OF COMPUTATIONAL FLUID DYNAMICS　23　(8)　583-593　2009

DOI： 10.1080/10618560902953575 　

ISSN： 1061-8562
Microvascular disorders induced by malaria infected red blood cells: a computational mechanical study using the biological particle method Invited

T. Yamaguchi, H. Kondo, Y. Imai, T. Ishikawa

MODELLING IN MEDICINE AND BIOLOGY VIII　13　49-+　2009

DOI： 10.2495/BIO090051 　

ISSN： 1743-3525
Behavior of a red blood cell in a simple shear flow simulated by a boundary element method

T. Omori, T. Ishikawa, D. Barthes-Biesel, Y. Imai, T. Yamaguchi

GPBE/NUS-Tohoku Graduate Student Conf. Bioeng., Program & Abstract　99-100　2008/12/01
A novel hemodynamic index for the initiation of cerebral aneurysms: focusing on temporal variation of spatial wall shear stress gradient

Y. Shimogonya, T. Ishikawa, Y. Imai, N. Matsuki, T. Yamaguchi

GPBE/NUS-Tohoku Graduate Student Conf. Bioeng., Program & Abstract　95-96　2008/12/01
Numerical simulation of inspiratory and expiratory pulmonary airflow using a subject-specific model

T. Miki, Y. Imai, T. Ishikawa, S. Wada, T. Yamaguchi

GPBE/NUS-Tohoku Graduate Student Conf. Bioeng., Program & Abstract　81-82　2008/12/01
Three-dimensional Simulation of Blood Flow in Malaria Infection

Y. Imai, H. Kondo, T. Ishikawa, C. T. Lim, K. Tsubota, T. Yamaguchi

Proc. 13th Int Conf. Biomed. Eng.　133　2008/12/01
Biomechanics of a suspension of micro-organisms Invited

T. Ishikawa

Proc. 13th Int Conf. Biomed. Eng.　14　2008/12/01
東北大学における「医療工学技術者創成のための再教育システム」の実践 Peer-reviewed

山野真裕, 松木範明, 沼山恵子, 武田元博, 早坂智明, 石川拓司, 山口隆美

工学教育　56　(6)　125-132　2008/12/01
Publisher: Japanese Society for Engineering Education
DOI： 10.4307/jsee.56.6_125 　

ISSN： 1341-2167

More details Close

Tohoku University promotes the "REDEEM" project, which is a national project of Recurrent Education for the Development of Engineering Enhanced Medicine. This education system provides a curriculum for engineers who belong to bio-medical R. In Japan, most of industrial engineers have been excluded from systemized bio-medical education, while medical and co-medical personnel lack engineering education. This difference of backgrounds causes a discrepancy between medicine and engineering bringing difficulty in collaboration for development of medical equipments or drugs. In this project, we focus on the engineering side, and we try to develop and provide a bio-medical engineering course for engineers. In this paper, we report and discuss on the outline and the progress of the "REDEEM" project.
Development of a Wearable System Module for Monitoring Physical and Mental Workload Peer-reviewed

Sinbae Kim, Hiromi Nakamura, Toshihiko Yoshida, Masamichi Kishimoto, Yohsuke Imai, Noriaki Matsuki, Takuji Ishikawa, Takami Yamaguchi

TELEMEDICINE JOURNAL AND E-HEALTH　14　(9)　939-945　2008/11

DOI： 10.1089/tmj.2008.0019 　

ISSN： 1530-5627
Development of coherent structures in concentrated suspensions of swimming model micro-organisms Peer-reviewed

Takuji Ishikawa, J. T. Locsei, T. J. Pedley

JOURNAL OF FLUID MECHANICS　615　401-431　2008/11

DOI： 10.1017/S0022112008003807 　

ISSN： 0022-1120
Waltzing Volvox: Orbiting Bound States of Flagellated Multicellular Algae

K. Drescher, K. Leptos, T. J. Pedley, R. E. Goldstein, T. Ishikawa

Bulletin of the American Physical Society, DFD 2008　53　238　2008/11/01
Numerical analysis of a stable waltzing pair of Volvox

T. Ishikawa, K. Drescher, K. Leptos, T. J. Pedley, R. E. Goldstein

Bulletin of the American Physical Society, DFD 2008　53　279　2008/11/01
Development of automatic respiration monitoring for home-care patients of respiratory diseases with therapeutic aids

M. Okubo, Y. Imai, T. Ishikawa, T. Hayasaka, S. Ueno, T. Yamaguchi

Int. Feder. Med. Biol. Eng. (IFMBE) Proc. (CD-ROM)　205　2008/11/01

DOI： 10.1007/978-3-540-89208-3_267 　
Development of a mobile toilet system servicing elderly on call

S. Ueno, T. Hayasaka, Y. Imai, M. Okubo, T. Ishikawa, T. Yamaguchi

Int. Feder. Med. Biol. Eng. (IFMBE) Proc. (CD-ROM)　234　2008/11/01

DOI： 10.1007/978-3-540-89208-3_416 　
A locomotive system mimicking pedal locomotion of snails for the capsule endoscope

D. Hosokawa, T. Ishikawa, H. Morikawa, Y. Imai, T. Yamaguchi

Int. Feder. Med. Biol. Eng. (IFMBE) Proc. (CD-ROM)　274　2008/11/01

DOI： 10.1007/978-3-540-89208-3_393 　
Three-dimensional simulation of malaria-infected blood

H. Kondo, Y. Imai, T. Ishikawa, K. Tsubota, C.T. Lim, T. Yamaguchi

Interntional Symposium on Nano-Biomedical Engineering7th Intrnational Symposium of 2007 Tohoku University Global COE Program "Global Nano-Biomedical Engineering Education and Research Network Centre"Nano-Biomedical Engineering in the East Asian-Pacific Ri　42-43　2008/10
Low voltage pulses can induce apoptosis Peer-reviewed

Noriaki Matsuki, Takuji Ishikawa, Yousuke Imai, Takami Yamaguchi

CANCER LETTERS　269　(1)　93-100　2008/09

DOI： 10.1016/j.canlet.2008.04.019 　

ISSN： 0304-3835
Inflow into saccular cerebral aneurysms at arterial bends Peer-reviewed

Yohsuke Imai, Kodai Sato, Takuji Ishikawa, Takami Yamaguchi

ANNALS OF BIOMEDICAL ENGINEERING　36　(9)　1489-1495　2008/09

DOI： 10.1007/s10439-008-9522-z 　

ISSN： 0090-6964
Mixing of red blood cells in a micro-channel flow under high hematocrit conditions

T. Ishikawa, R. Lima, H. Fujiwara, Y. Imai, N. Matsuki, T. Yamaguchi

Bioengineering 08 Book of Abstracts　61　2008/09/01
A Numerical Method for Simulating Micro-Scale Blood Flow in Malaria Infection

Y. Imai, H. Kondo, T. Ishikawa, K. Tsubota, C. T. Lim, T. Yamaguchi

Bioengineering 08 Book of Abstracts　125　2008/09/01
Behavior of a Red Blood Cell in a Simple Shear Flow Simulated by a Boundary Element Method

T. Omori, T. Ishikawa, D. Barthes-Biesel, Y. Imai, T. Yamaguchi

Bioengineering 08 Book of Abstracts　135　2008/09/01
Confocal micro-PTV Measurements of Blood Flow in a Circular PDMS Microchannel

R. Lima, T. Ishikawa, H. Kaji, Y. Imai, S. Wada, M. Nishizawa, T. Yamaguchi

Bioengineering 08 Book of Abstracts　166　2008/09/01
Proposal of a New Hemodynamic Index for Cerebral Aneurysm Initiation: Focusing on Temporal Fluctuation of Spatial Wall Shear Stress Gradient

Y. Shimogonya, T. Ishikawa, Y. Imai, N. Matsuki, T. Yamaguchi

Bioengineering 08 Book of Abstracts　146　2008/09/01
The importance of parent artery geometry in intra-aneurysmal hemodynamics Peer-reviewed

Kodai Sato, Yohsuke Imai, Takuji Ishikawa, Noriaki Matsuki, Takami Yamaguchi

MEDICAL ENGINEERING & PHYSICS　30　(6)　774-782　2008/07

DOI： 10.1016/j.medengphy.2007.09.006 　

ISSN： 1350-4533
Radial dispersion of red blood cells in blood flowing through glass capillaries: The role of hematocrit and geometry Peer-reviewed

Rui Lima, Takuji Ishikawa, Yohsuke Imai, Motohiro Takeda, Shigeo Wada, Takami Yamaguchi

JOURNAL OF BIOMECHANICS　41　(10)　2188-2196　2008/07

DOI： 10.1016/j.jbiomech.2008.04.033 　

ISSN： 0021-9290

eISSN： 1873-2380
Role of the hematocrit on the radial dispersion of red blood cells in glass capillaries

R. Lima, T. Ishikawa, Y. Imai, M. Takeda, S. Wada, T. Yamaguchi

Journal of Biomechanics　41　S334　2008/07/01

DOI： 10.1016/j.jbiomech.2008.04.033 　
Motion of red blood cells and cell free layer distribution in a stenosed microchannel

H.Fujiwara, T. Ishikawa, R. Lima, Y. Imai, N. Matsuki, D. Mori, T. Yamaguchi

Journal of Biomechanics　41　S390　2008/07/01
Determination of blood cells motions and interactions by a confocal micro-PTV system

R. Lima, T. Ishikawa, Y. Imai, M. Takeda, S. Wada, T. Yamaguchi

Journal of Biomechanics　41　S429　2008/07/01
A numerical model of blood flow with malariainfected red blood cells

Y. Imai, H. Kondo, T. Ishikawa, K. Tsubota, T. Yamaguchi

Journal of Biomechanics　41　S480　2008/07/01
Stokesian-Dynamics Simulation of a Suspension of Swimming Micro-Organisms Invited Peer-reviewed

T. Ishikawa, J. T. Locsei, T. J. Pedley, T. Yamaguchi

IACM/ECCOMAS Congress 2008 CD-ROM　MS194D　2008/07/01
Image-based pulmonary airflow simulation using cartesian adaptive mesh refinement method

T. Miki, Y. Imai, M. Nakamura, C. Iwamura, T. Ishikawa, S. Wada, T. Yamaguchi

IACM/ECCOMAS Congress 2008 CD-ROM　MS070B　2008/07/01
Three-Dimensional Simulation of Blood Flow arising from Malaria Infection

H. Kondo, Y. Imai, T. Ishikawa, K. Tsubota, C. T. Lim, T. Yamaguchi

IACM/ECCOMAS Congress 2008 CD-ROM　MS194C　2008/07/01
Multi-scale multi-physics simulations of Biological flows

T. Yamaguchi, T. Miki, Y. Shimogonya, H. Kondo, D. Mori, Y. Imai, M. Nakamura, C. Iwamura, S. Wada, T. Ishikawa

Int. Symp. Multi-scale Sim. Biol. Soft Mater. (MSBSM2008) Book of Abstracts　2-3　2008/06/01
The importance of proliferation of the arterial wall in formation of saccular cerebral aneurysms

Y. Shimogonya, T. Ishikawa, Y. Imai, D. Mori, T. Yamaguchi

Proc. ASME 2008 Summer Bioeng. Conf.CD-ROM　2008/06/01
Pulmonary airflow simulation using subject-specific model and Cartesian adaptive mesh refinement method

T. Miki, Y. Imai, S. Wada, T. Ishikawa, T. Yamaguchi

Proc. Tohoku-NUS Student Joint Symp　16-17　2008/05/01
Collective motions of locomotive cells in a suspension Invited

T. Ishikawa

Proc. Tohoku-NUS Student Joint Symp　18-19　2008/05/01
In vitro blood flow in a rectangular PDMS microchannel: experimental observations using a confocal micro-PIV system Peer-reviewed

Rui Lima, Shigeo Wada, Shuji Tanaka, Motohiro Takeda, Takuji Ishikawa, Ken-ichi Tsubota, Yohsuke Imai, Takami Yamaguchi

BIOMEDICAL MICRODEVICES　10　(2)　153-167　2008/04

DOI： 10.1007/s10544-007-9121-z 　

ISSN： 1387-2176
Shear-induced fluid-tracer diffusion in a semidilute suspension of spheres Peer-reviewed

Takuji Ishikawa, Takami Yamaguchi

PHYSICAL REVIEW E　77　(4)　041402　2008/04

DOI： 10.1103/PhysRevE.77.041402 　

ISSN： 1539-3755
CT image-based pulmonary airflow simulation using airway scale determined mesh

T. Miki, Y. Imai, M. Nakamura, C. Iwamura, T. Ishikawa, S. Wada, T. Yamaguchi

Fifth International Bio-Fluid Symposium and Workshop　146-147　2008/03/01
Computational mechanical analysis of primary thrombus formation in a blood flow

D. Mori, K. Yano, K. Tsubota, T. Ishikawa, S. Wada, T. Yamaguchi

Fifth International Bio-Fluid Symposium and Workshop　110-111　2008/03/01
Some uninvestigated directions of computational fluid dynamics studies for flow

T. Yamaguchi, T. Miki, Y. Shimogonya, H. Kondo, D. Mori, Y. Imai, M. Nakamura, C. Iwamura, S. Wada, T. Ishikawa

Fifth International Bio-Fluid Symposium and Workshop　65-66　2008/03/01
Microscale flow dynamics of red blood cells in a circular microchannel Peer-reviewed

R. Lima, M. Nakamura, T. Ishikawa, S. Tanaka, M. Takeda, Y. Imai, K. Tsubota, S. Wada, T. Yamaguchi

COMPUTATIONAL VISION AND MEDICAL IMAGING PROCESSING　53-+　2008
Simulation of platelet adhesion and aggregation regulated by fibrinogen and von Willebrand factor Peer-reviewed

Daisuke Mori, Koichiro Yano, Ken-ichi Tsubota, Takuji Ishikawa, Shigeo Wada, Takami Yamaguchi

THROMBOSIS AND HAEMOSTASIS　99　(1)　108-115　2008/01

DOI： 10.1160/TH07-08-0490 　

ISSN： 0340-6245
A Rule-Based Computational Study on the Early Progression of Intracranial Aneurysms Using Fluid-Structure Interaction: Comparison between Straight Model and Curved Model Peer-reviewed

Yixiang Feng, Shigeo Wada, Takuji Ishikawa, Ken-Ichi Tsubota, Takami Yamaguchi

Journal of Biomechanical Science and Engineering　3　(2)　124-137　2008

DOI： 10.1299/jbse.3.124 　

ISSN： 1880-9863
Computational study on effect of red blood cells on primary thrombus formation Peer-reviewed

Daisuke Mori, Koichiro Yano, Ken-ichi Tsubota, Takuji Ishikawa, Shigeo Wada, Takami Yamaguchi

THROMBOSIS RESEARCH　123　(1)　114-121　2008

DOI： 10.1016/j.thromres.2008.03.006 　

ISSN： 0049-3848
Formation of Saccular Cerebral Aneurysms May Require Proliferation of the Arterial Wall: Computational Investigation Peer-reviewed

Yuji Shimogonya, Takuji Ishikawa, Yohsuke Imai, Daisuke Mori, Noriaki Matsuki, Takami Yamaguchi

Journal of Biomechanical Science and Engineering　3　(3)　431-442　2008

DOI： 10.1299/jbse.3.431 　

ISSN： 1880-9863
Tracking of red blood cells in microchannel with stenosis by confocal micro PTV system Peer-reviewed

H. Fujiwara, T. Ishikawa, R. Lima, Y. Imai, N. Matsuki, H. Kaji, D. Mori, M. Nishizawa, T. Yamaguchi

Proc. 7th Int. Symp. Adv. Fluid Info. & 4th Int. Symp. Transdisciplinary Fluid Integr.　56-57　2007/12/01
Blood flow in microchannel with stenosis measured by a confocal micro PTV system Peer-reviewed

H. Fujiwara, T. Ishikawa, R. Lima, Y. Imai, N. Matsuki, H. Kaji, D. Mori, M. Nishizawa, T. Yamaguchi

Proc. 3rd Tohoku-NUS Joint Symp. Nano-Biomed. Eng. in the East Asian-Pacific Rim Region　99-100　2007/12/01
Development of respiration measurement system with conductive rubber for elderly home care Peer-reviewed

M. Okubo, M. Kishimoto, Y. Imai, T. Ishikawa, T. Yamaguchi

Proc. 3rd Tohoku-NUS Joint Symp. Nano-Biomed. Eng. in the East Asian-Pacific Rim Region　47-48　2007/12/01
Modeling of malaria-infected red blood cell mechanics using a particle method Peer-reviewed

H. Kondo, Y. Imai, K. Tsubota, T. Ishikawa, T. Yamaguchi

Proc. APCOM'07 in conjunction with EPMESC XI　CD-ROM MS22-4-2　2007/12/01
Numerical simulation of cerebral aneurysm growth based on a hemodynamic hypothesis Peer-reviewed

Y. Shimogonya, T. Ishikawa, Y. Imai, T. Yamaguchi

Proc. APCOM'07 in conjunction with EPMESC XI　CD-ROM MS22-3-3　2007/12/01
Suspensions of swimming micro-organisms Peer-reviewed

T. Ishikawa

Proc. APCOM'07 in conjunction with EPMESC XI　CD-ROM MS22-1-2　2007/12/01
An AMR Method based on the IDO scheme for patient-specific pulmonary airflow simulation Peer-reviewed

Y. Imai, T. Miki, T. Ishikawa, M. Nakamura, S. Wada, T. Yamaguchi

Proc. APCOM'07 in conjunction with EPMESC XI　CD-ROM MS7-1-3　2007/12/01
Development of a wearable surveillance system using gait analysis Peer-reviewed

Toshihiko Yoshida, Fumio Mizuno, Tomoaki Hayasaka, Kenichi Tsubota, Yousuke Imai, Takuji Ishikawa, Takami Yamaguchi

TELEMEDICINE JOURNAL AND E-HEALTH　13　(6)　703-713　2007/12

DOI： 10.1089/tmj.2007.0015 　

ISSN： 1530-5627
CT Image-Based Respiratory Flow Simulation by using Cartesian Adaptive Mesh Refinement Method Peer-reviewed

T. Miki, Y. Imai, M. Nakamura, T. Ishikawa, S. Wada, T. Yamaguchi

Proc. Int. Conf. Adaptive Modeling & Simulation　166-169　2007/11/30
A Cartesian Adaptive Mesh Refinement Method for Simulating Physiological Flows Peer-reviewed

Y. Imai, T. Miki, T. Aoki, M. Nakamura, T. Ishikawa, S. Wada, T. Yamaguchi

Proc. Int. Conf. Adaptive Modeling & Simulation　128-131　2007/11/30
The role of near field interactions in the collective behaviour of model swimming micro-organisms Peer-reviewed

T. Locsei, T. Ishikawa, T. J. Pedley

Bulletin of the American Physical Society　52　245　2007/11/21
The hydrodynamics of interactions between two swimming bacteria Peer-reviewed

T. Ishikawa, G. Sekiya, Y. Imai, T. Yamaguchi

Bulletin of the American Physical Society　52　245-246　2007/11/21
Relaxation Time of Bottom-Heavy Squirmers in a Semi-Dilute Suspension Peer-reviewed

T. Ishikawa, T. J. Pedley, T. Yamaguchi

Proc. 3rd Asian Pacific Conf. Biomech.　S227　2007/11/01
Numerical Simulation of Malaria-Infected Blood Flow using a Particle Method Peer-reviewed

H. Kondo, Y. Imai, K. Tsubota, T. Ishikawa, T. Yamaguchi

Proc. 3rd Asian Pacific Conf. Biomech.　S226　2007/11/01
Computational Study of Platelet Thrombus Formation in a Blood Flow Peer-reviewed

D. Mori, K. Yano, K. Tsubota, T. Ishikawa, S. Wada, T. Yamaguchi

Proc. 3rd Asian Pacific Conf. Biomech.　S225　2007/11/01
Measurement of Respiration by a Hyper Diaper with Conductive Rubber Peer-reviewed

M. Okubo, M. Kishimoto, S. Kim, Y. Imai, T. Ishikawa, T. Yamaguchi

Proc. 3rd Asian Pacific Conf. Biomech.　S206　2007/11/01
Monitoring Physical and Mental Workloads by a Wearable Computer Peer-reviewed

S. Kim, H. Nakamura, M. Kishimoto, Y. Imai, N. Matsuki, T. Ishikawa, T. Yamaguchi

Proc. 3rd Asian Pacific Conf. Biomech.　S103　2007/11/01
Measurement of Multi-Red Blood Cells Interactions in Blood Flow by Confocal Micro-PTV Peer-reviewed

R. Lima, T. Ishikawa, H. Fujiwara, M. Takeda, Y. Imai, K. Tsubota, N. Matsuki, S. Wada, T. Yamaguchi

Proc. 3rd Asian Pacific Conf. Biomech.　S92　2007/11/01
Observation of the Blood Flow in Microchannel with Stenosis by Confocal-Micro-PIV Peer-reviewed

H. Fujiwara, T. Ishikawa, R. Lima, H. Kaji, N. Matsuki, Y. Imai, M. Nishizawa, T. Yamaguchi

Proc. 3rd Asian Pacific Conf. Biomech.　S89　2007/11/01
Development of a Wearable System for Monitoring Health Condition Peer-reviewed

M. Kishimoto, T. Yoshida, H. Nakamura, M. Okubo, Y. Suzuki, S. Kim, T. Hayasaka, Y. Imai, K. Tsubota, T. Ishikawa, T. Yamaguchi

Proc. 3rd Asian Pacific Conf. Biomech.　S84　2007/11/01
A Simulation Model for Cerebral Aneurysm Growth based on a Hemodynamic Hypothesis Peer-reviewed

Y. Shimogonya, T. Ishikawa, Y. Imai, T. Yamaguchi

Proc. 3rd Asian Pacific Conf. Biomech.　S76　2007/11/01
CFD Study on Mass Transport to Saccular Aneurysms at Arterial Bend Peer-reviewed

Y. Imai, K. Sato, T. Ishikawa, A. Comerford, T. David, T. Yamaguchi

Proc. 3rd Asian Pacific Conf. Biomech.　S58　2007/11/01
Orientational relaxation time of bottom-heavy squirmers in a semi-dilute suspension Peer-reviewed

T. Ishikawa, T. J. Pedley, T. Yamaguchi

JOURNAL OF THEORETICAL BIOLOGY　249　(2)　296-306　2007/11

DOI： 10.1016/j.jtbi.2007.07.033 　

ISSN： 0022-5193
Properties of a Semi-dilute Suspension of Swimming Micro-organisms Peer-reviewed

T. Ishikawa, T. Yamaguchi, T. J. Pedley

Bio-mechanisms of Swimming and Flying, Springer-Verlag　17-28　2007/10/01
CFD modeling of pulmonary airflow using IDO-AMR method Peer-reviewed

Y. Imai, T. Miki, S. Wada, M. Nakamura, T. Ishikawa, T. Yamaguchi

Proc. 4th Japan-Taiwan Workshop on Mech. & Aerospace Eng.　289-294　2007/10/01
Properties of a suspension of swimming micro-organisms Peer-reviewed

T. Ishikawa

Proc. 4th Japan-Taiwan Workshop on Mech. & Aerospace Eng.　265-274　2007/10/01
The rheology of a semi-dilute suspension of swimming model micro-organisms Peer-reviewed

Takuji Ishikawa, T. J. Pedley

JOURNAL OF FLUID MECHANICS　588　399-435　2007/10

DOI： 10.1017/S0022112007007835 　

ISSN： 0022-1120
Diffusion of swimming model micro-organisms in a semi-dilute suspension Peer-reviewed

Takuji Ishikawa, T. J. Pedley

JOURNAL OF FLUID MECHANICS　588　437-462　2007/10

DOI： 10.1017/S0022112007007847 　

ISSN： 0022-1120
Hydrodynamic interactions between two swimming bacteria Peer-reviewed

T. Ishikawa, G. Sekiya, Y. Imai, T. Yamaguchi

BIOPHYSICAL JOURNAL　93　(6)　2217-2225　2007/09

DOI： 10.1529/biophysj.107.110254 　

ISSN： 0006-3495
A fluid-solid interactions study of the pulse wave velocity in uniform arteries Peer-reviewed

T. Fukui, Y. Imai, K. Tsubota, T. Ishikawa, S. Wada, T. Yamaguchi

Biomechanics at micro- and nanoscale levels, World Scientific　3　146-156　2007/06/01
Numerical simulation of a suspension of swimming micro-organisms

T. Ishikawa, T. J. Pedley, T. Yamaguchi

Proc. 2007 Summer Bioengineering Conference　CD-ROM　175256　2007/06/01
Measurement of erythrocyte motions in microchannels by using a confocal micro-PTV system

R. Lima, T. Ishikawa, M. Takeda, S. Tanaka, Y. Imai, K. Tsubota, S. Wada, T. Yamaguchi

Proc. 2007 Summer Bioengineering Conference　CD-ROM　175969　2007/06/01
Wall shear stress change due to arterial wall stiffness; fluid-solid interaction study

T. Fukui, K. H. Parker, Y. Imai, K. Tsubota, T. Ishikawa, S. Wada, T. Yamaguchi

Proc. 2007 Summer Bioengineering Conference　CD-ROM　176102　2007/06/01
Image-based simulation of pulmonary airflow using multi-level voxel modeling

Y. Imai, T. Miki, M. Nakamura, T. Ishikawa, S. Wada, T. Yamaguchi

Proc. 2007 Summer Bioengineering Conference　CD-ROM　176529　2007/06/01
A simulation study on the growth of cerebral aneurysms

Y. Shimogonya, Y. Imai, T. Ishikawa, T. Yamaguchi

Proc. 2007 Summer Bioengineering Conference　CD-ROM　176106　2007/06/01
Effect of the red blood cells on the primary thrombus formation

K. Yano, D. Mori, K. Tsubota, T. Ishikawa, S. Wada, T. Yamaguchi

Proc. 2007 Summer Bioengineering Conference　CD-ROM　176360　2007/06/01
Effects of arterial geometry on inflow rate into cerebral aneurysms on curved arteries

Y. Imai, K. Sato, T. Ishikawa, T. Yamaguchi

Proc. 2007 Summer Bioengineering Conference　CD-ROM　176556　2007/06/01
Effect of the wall motion on arterial wall shear stress Peer-reviewed

T. Fukui, K. H. Parker, Y. Imai, K. Tsubota, T. Ishikawa, S. Wada, T. Yamaguchi

Journal of Biomechanical Science and Engineering　2　(2)　58-68　2007/05/01
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jbse.2.58 　

ISSN： 1880-9863

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The distribution of wall shear stress (WSS) in arteries is affected by both blood and wall motion. Most studies have ignored wall motion by assuming that the artery wall is rigid. To investigate the influence of wall motion we have solved the coupled fluid-solid problem in a straight homogeneous tube. The inlet boundary condition of the tube was given as a pulse of velocity imposed at the inlet of the tube upon a steady flow of Reynolds number 1000. A commercial code (Radioss, Altair Engineering) was used to solve the fluid-solid interactions. Two kinds of waves are generated on the wall by the pulse imposed in the inlet flow; a wave of longitudinal motion of the wall (the longitudinal wave) and a wave of radial motion of the wall (the elastic wave). The ends of the vessel are assumed to be fixed which results in the reflection of both waves. The longitudinal wall motion reduces the relative speed of the blood, reducing WSS by up to 0.5 Pa. The largest effect of wall motion occurs when the longitudinal and elastic waves coincide, where the peak WSS is reduced by 1.0 Pa, which is a significant fraction of the observed WSS. Thus we can say that the effect of wall motion is important in considering physiological response of arterial wall to the blood flow.
Analysis of destruction process of the primary thrombus under the influence of the blood flow Peer-reviewed

K. Yano, D. Mori, K. Tsubota, T. Ishikawa, S. Wada, T. Yamaguchi

Journal of Biomechanical Science and Engineering　2　(1)　34-44　2007/04
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jbse.2.34 　

ISSN： 1880-9863

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Stokesian dynamics method based on the approximation of the additivity of velocities was employed to analyze the mechanical behavior of the primary thrombus under the blood flow. The mechanical interactions in the platelet-platelet aggregation and the platelet-surface adhesion via biological macromolecules such as von Willebrand factor and fibrinogen was modeled by the Voigt model. The process of the primary thrombus destruction was simulated under different levels of the mechanical interaction using the developed method. When the binding force was weak, which corresponds to the decline of the platelet function in the bleeding diseases, it was demonstrated that the platelets did not efficiently reside on the injured site of the vessel wall. The results show that our modeling can qualitatively demonstrate the effect of the mechanical interaction via adhesive macromolecules on the destruction process of the primary thrombus. Our modeling could be a powerful tool to better understand the physiological hemostatic mechanism as well as the pathology of the thrombosis and the bleeding disorders.
64チャンネルマルチスライスCTを用いた肺気道形態の計測

三木貴仁, 中村匡徳, 須田祐司, 田村弦, 今井陽介, 石川拓司, 山口隆美, 和田成生

呼吸　26　(2Suppl.)　S7-S10　2007/02
Publisher: (一社)呼吸研究
ISSN： 0286-9314
Numerical simulation of a low-hematocrit blood flow in a small artery with stenosis Peer-reviewed

T. Ishikawa, N. Kawabata, Y. Imai, K. Tsubota, T. Yamaguchi

Journal of Biomechanical Science and Engineering　2　(1)　12-22　2007/02/01
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jbse.2.12 　

ISSN： 1880-9863

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The blood flow in a large artery is commonly analyzed by means of constitutive equations. However, it is not appropriate to use these equations for small arteries because of the heterogeneity of the blood. In this study, we use a bead-spring model for an erythrocyte to simulate a low-hematocrit blood flow in a small artery with a stenosis. The flow field is solved using Euler coordinates, whereas the motion of the erythrocyte is solved using Lagrangian coordinates (two-way coupling). The results show that the erythrocytes are considerably deformed around the stenosis and that the separated region downstream of the stenosis is weakened by the erythrocytes.
A Fluid-Solid Interaction Study of the Pulse Wave Velocity in Uniform Arteries Peer-reviewed

T. Fukui, Kim. H. Parker, Y. Imai, K. Tsubota, T. Ishikawa, S. Wada, T. Yamaguchi

Proc. Final Symp. Tohoku University 21st Century of Excellence Program　919-927　2007/01/02
Velocity Fields of Blood Flow in Microchannels Using a Confocal Micro-PIV System Peer-reviewed

R. Lima, T. Ishikawa, S. Tanaka, M. Takeda, K. Tsubota, S. Wada, T. Yamaguchi

Proc. Final Symp. Tohoku University 21st Century of Excellence Program　973-980　2007/01/02
Computational biomechanics of blood flow in cardiovascular diseases Peer-reviewed

T. Yamaguchi, T. Ishikawa, K. Tsubota, Y. Imai, D. Mori, N. Matsuki

Biomechanics at Micro- and Nanoscale Levels　4　130-140　2007/01/01
Publisher: World Scientific Publishing Co.
DOI： 10.1142/9789812771322_0012 　
Effect of Aneurysmal Geometry on the Distribution of ATP Concentration Peer-reviewed

K. Sato, Y. Imai, T. Ishikawa, A. Comerford, T. David, T. Yamaguchi

The 9th Int. Symp. Future Med. Eng. based on Bio-nanotech.　128-129　2007/01/01
Tracking Red Blood Cells in a Circular PDMS Microchannel using a Confocal Micro-PIV System Peer-reviewed

R. Lima, T. Ishikawa, S. Tanaka, M. Takeda, Y. Imai, K. Tsubota, S. Wada, T. Yamaguchi

The 9th Int. Symp. Future Med. Eng. based on Bio-nanotech.　126-127　2007/01/01
Numerical Simulation on the Growth of Saccular Aneurysm Peer-reviewed

Y. Shimogonya, Y. Imai, T. Ishikawa, T. Yamaguchi

The 9th Int. Symp. Future Med. Eng. based on Bio-nanotech.　94-95　2007/01/01
Development of a wearable watch over system for patients home with an accelerometer Peer-reviewed

T. Yoshida, H. Nakamura, M. Kishimoto, F. Mizuno, T. Hayasaka, K. Tsubota, Y. Imai, T. Ishikawa, T. Yamaguchi

Proc. 2nd Tohoku-NUS Joint Symp. Future Nano-med. Bioeng. in the East Asian Region as the 8th Int. Symp. Future Med. Eng. Based on Bio-nanotech.　120-121　2006/12/01
Numerical analysis of ATP transport in aneurysms Peer-reviewed

K. Sato, Y. Imai, T. Ishikawa, A. Comerford, T. David, T. Yamaguchi

Proc. 2nd Tohoku-NUS Joint Symp. Future Nano-med. Bioeng. in the East Asian Region as the 8th Int. Symp. Future Med. Eng. Based on Bio-nanotech.　118-119　2006/12/01
Monitoring physical and mental workloads by wearable system for elderly home care Peer-reviewed

H. Nakamura, T. Yoshida, Y. Imai, T. Ishikawa, T. Yamaguchi

Proc. 2nd Tohoku-NUS Joint Symp. Future Nano-med. Bioeng. in the East Asian Region as the 8th Int. Symp. Future Med. Eng. Based on Bio-nanotech.　122-123　2006/12/01
Development of a wearable system for an quantification measurment of human motions in daily life Peer-reviewed

M. Kishimoto, H. Nakamura, T. Yoshida, F. Mizuno, T. Hayasaka, Y. Imai, K. Tsubta, T. Ishikawa, T. Yamaguchi

Proc. 15th Int. Conf. Mechanics in Medicine and Biology　187-188　2006/12
Computer simulation of effects of deformabilities of red blood cells on blood flow using particle method Peer-reviewed

K. Tsubota, S. Wada, Y. Imai, T. Ishikawa, T. Yamaguchi

Proc. 15th Int. Conf. Mechanics in Medicine and Biology　422-423　2006/12
An adaptive mesh refinement method for CFD analysis of arterial blood flow Peer-reviewed

Y. Imai, T. Aoki, T. Ishikawa, K. Tsubota, T. Yamaguchi

Proc. 15th Int. Conf. Mechanics in Medicine and Biology　80-81　2006/12
Numerinal simulation of a low Hematocrit blood flow in a small artery with stenosis Peer-reviewed

T. Ishikawa, N. Kawabata, Y. Imai, K. Tsubota, T. Yamaguchi

Proc. 15th Int. Conf. Mechanics in Medicine and Biology　420-421　2006/12
Hydrodynamic interaction of two swimming model micro-organisms Peer-reviewed

Takuji Ishikawa, M. P. Simmonds, T. J. Pedley

JOURNAL OF FLUID MECHANICS　568　119-160　2006/12

DOI： 10.1017/S0022112006002631 　

ISSN： 0022-1120
A simple model for the diffusion of swimming model microorganisms

T. Locsei, T. Ishikawa, T. J. Pedley

Bulletin of the American Physical Society, DFD　51　(9)　54　2006/11
Microstructure of concentrated suspensions of swimming model micro-organisms

T. Ishikawa, T. Yamaguchi, T. J. Pedley

Bulletin of the American Physical Society, DFD　51　(9)　53　2006/11
Interaction of two swimming Paramecia Peer-reviewed

Takuji Ishikawa, Masateru Hota

JOURNAL OF EXPERIMENTAL BIOLOGY　209　(22)　4452-4463　2006/11

DOI： 10.1242/jeb.02537 　

ISSN： 0022-0949
From passive motion of capsules to active motion of cells Invited Peer-reviewed

D. Barthes-Biesel, T. Yamaguchi, T. Ishikawa, E. Lac

Journal of Biomechanical Science and Engineering　1　(1)　51-68　2006/10/01
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jbse.1.51 　

ISSN： 1880-9863

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In the past three decades, there has been great progress in the mathematical modeling and computational methods for fluid mechanics of suspensions of micron-scale particles. In medical or biological applications, the particles can be very deformable, self propelled or both. Research on mathematical and computational methods for the modelling of suspensions of such particles is currently very active. In this review paper, we introduce some of the concepts that are used to analyse suspensions of either passive deformable particles or active locomotive particles. To simplify matters, we consider simple model particles that are initially spherical. In one case, the particle is a liquid droplet enclosed by a thin deformable membrane (a 'capsule') and is deformed by hydrodynamic forces. In the other case, the particle remains spherical but propels itself by means of a velocity wave on its surface. Athough the basic equations for locomotive spherical cells and for capsules are similar, the resulting suspension characteristics are quite different owing to the different boundary conditions on the surface of the particles.
Computational Blood Flow Analysis-New Trends and Methods Invited Peer-reviewed

T. Yamaguchi, T. Ishikawa, K. Tsubota, Y. Imai, M. Nakamura, T. Fukui

Journal of Biomechanical Science and Engineering　1　(1)　29-50　2006/10/01
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jbse.1.29 　

ISSN： 1880-9863

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Over the past few decades, a large number of novel numerical methods have been proposed to analyze blood flows and to understand the relationship between vascular diseases and hemodynamics. In this paper, we review recent computational fluid dynamics studies on macroscale hemodynamics such as blood flow in the heart and large arteries, microscale blood flows in small vessels in which blood is assumed to be a suspension of red blood cells in plasma, and single red blood cell motions in an induced flow field. The advantages and disadvantages of numerical methods are discussed, and current trends in these research fields are introduced.
Velocity measurements of blood flow in a rectangular PDMS microchannel assessed by confocal micro-PIV system

R. Lima, S. Wada, S. Tanaka, M. Takeda, K. Tsubota, T. Ishikawa, T. Yamaguchi

IFMBE Proc. World Congress on Medical Physics and Biomedical Engineering　278-281　2006/09
Hydrodynamic aggregation and diffusion in populations of model micro-organisms

T. J. Pedley, T. Ishikawa

J. Biomechanics　39　S349　2006/08
Hydrodynamic interaction of two swimming Caudatum

T. Ishikawa, M. Hota, T. J. Pedley

J. Biomechanics　39　S349　2006/08
Deformation of a capsule in a low Re number simple shear flow Peer-reviewed

T. Ishikawa, K. Kamemoto, N. Kawabata

Transactions of the Japan Society of Mechanical Enginees, B　72　1927-1934　2006/08/01

DOI： 10.1299/kikaib.72.1927 　
Collective Motion of Swimming Model Micro-organisms in a Concentrated Suspension

T. Ishikawa, T. J. Pedley

Proc. 3rd Int. Symp. Aero Aqua Bio-mech.　(CD-ROM)　S04　2006/07
Modelling populations of swimming micro-organisms

T. J. Pedley, T. Ishikawa

Oberwolfach Report　(24)　31-32　2006/05
Mass transport in pulsatile flow through asymmetric stenosis Peer-reviewed

Takuji Ishikawa, Shuzo Oshima, Ryuichiro Yamane, Hiroshi Wada

JSME International Journal, Series C: Mechanical Systems, Machine Elements and Manufacturing　44　(4)　1005-1012　2001/12

DOI： 10.1299/jsmec.44.1005 　

ISSN： 1344-7653
Proposal of a deformable erythrocyte model and numerical analysis of shear flow of blood Peer-reviewed

T Ishikawa, N Kawabata, M Tachibana

JSME INTERNATIONAL JOURNAL SERIES C-MECHANICAL SYSTEMS MACHINE ELEMENTS AND MANUFACTURING　44　(4)　964-971　2001/12

ISSN： 1344-7653
Vortex enhancement in blood flow through stenosed and locally expanded tubes Peer-reviewed

Takuji Ishikawa, Shuzo Oshima, Ryuichiro Yamane

Fluid Dynamics Research　26　(1)　35-52　2000/01
Publisher: Elsevier Science B.V.
DOI： 10.1016/S0169-5983(98)00047-1 　

ISSN： 0169-5983
Modeling and numerical simulation of axisymmetric stenosis growth in an artery Peer-reviewed

Takuji Ishikawa, Shuzo Oshima, Ryiuchiro Yamane

Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B　65　(637)　2982-2989　1999
Publisher: Japan Society of Mechanical Engineers
DOI： 10.1299/kikaib.65.2982 　

ISSN： 0387-5016
Resonance of vortex in pulsatile flow through asymmetric stenosis Peer-reviewed

Takuji Ishikawa, Shuzo Oshima, Ryuichiro Yamane

Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B　65　(639)　3546-3553　1999
Publisher: Japan Society of Mechanical Engineers
DOI： 10.1299/kikaib.65.3546 　

ISSN： 0387-5016

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Misc. 155

Editorial: Ethological dynamics in diorama environments

Toshiyuki Nakagaki, Audrey Dussutour, Laurence Wilson, Takuji Ishikawa

Frontiers in Cell and Developmental Biology　11　1347957　2024/01
Bacterial behaviors in confined diorama environments

Takuji Ishikawa

Biophysical Journal　121　(13)　2487-2489　2022/07
Publisher: Elsevier BV
DOI： 10.1016/j.bpj.2022.05.045 　

ISSN： 0006-3495
Collision of two deformable torque swimmers

Hitomu Matsui, Toshihiro Omori, Takuji Ishikawa

72nd Annual Meeting of the APS Division of Fluid Dynamics　P31.00009　2019/11
How do colonial micro-algae swim towards light?

Helene De Maleprade, Frederic Moisy, Takuji Ishikawa, Raymond E. Goldstein

72nd Annual Meeting of the APS Division of Fluid Dynamics　H31.00003　2019/11
Pump Function of C. elegans Pharynx in Highly Viscous Environments

Yuki Suzuki, Kenji Kikuchi, Keiko Numayama-Tsuruta, Takuji Ishikawa

72nd Annual Meeting of the APS Division of Fluid Dynamics　G29.00004　2019/11
Mixing and pumping functions in a zebrafish larval intestine

Kenji Kikuchi, Hyeongtak Noh, Keiko Numayama-Tsuruta, Takuji Ishikawa

72nd Annual Meeting of the APS Division of Fluid Dynamics　G29.00003　2019/11
Harnessing low Reynolds number flow for net migration: Locomotion of a deformable microcapsule by random fluid forces

Takuji Ishikawa, Takeru Morita, Toshihiro Omori, Yohei Nakayama, Shoichi Toyabe

72nd Annual Meeting of the APS Division of Fluid Dynamics　C35.00008　2019/11
Towards the rheology of a concentrated array of spherical squirmers

Tim Pedley, Takuji Ishikawa, Douglas Brumley

72nd Annual Meeting of the APS Division of Fluid Dynamics　C32.00003　2019/11
Numerical Simulation of Hydrodynamic Interaction Between Swimming Spermatozoa

Nanami Taketoshi, Toshihiro Omori, Takuji Ishikawa

10th Asian-Pacific Conference on Biomechanics　PO02　2019/11
Numerical Simulation of a Droplet Propelled by Collective Swimming of Microorganisms

Zhihan Huang, Toshihiro Omori, Takuji Ishikawa

10th Asian-Pacific Conference on Biomechanics　S1-1　2019/11
Inflamed Intestinal Flow in Zebrafish Larva

Masahiro Takahashi, K. Numayama-Tsuruta, Kenji Kikuchi, Takuji Ishikawa

10th Asian-Pacific Conference on Biomechanics　S1-4　2019/11
On Transport of Yeasts

Atul Srivastava, Kenji Kikuchi, Takuji Ishikawa

10th Asian-Pacific Conference on Biomechanics　S1-3　2019/11
Pumping Function for a Fresh-water Sponge

S. Koyama, K. Kikuchi, K. Numayama-Tsuruta, T. Ishikawa

16th International Conference on Fluid Dynsmics　OS8-10　2019/11
Simulation of a Biofilm-Formation in a Microfluidic Channel

H. Kitamura , T. Omori, T. Ishikawa

16th International Conference on Fluid Dynsmics　OS11-6　2019/11
High Viscous Fluid Flow in C. elegans Pharynx

Y. Suzuki, K. Kikuchi, K. Numayama-Tsuruta, T. Ishikawa

16th International Conference on Fluid Dynsmics　OS11-4　2019/11
Enhancement of Transdermal Drug Delivery by Rotational Stimulation Device

Y. Kurosawa, K. Kikuchi, K. Numayama-Tsuruta, T. Ishikawa

16th International Conference on Fluid Dynsmics　OS9-15　2019/11
Micro-capsule swimmer controlled by flow oscillations

T. Morita, T. Omori, T. Ishikawa

Bulletin of the American Physical Society, DFD 2018　63　(13)　540　2018/11
Hydrodynamics of ciliate swimming revealed by individual ciliary motions

H. Ito, T. Omori, T. Ishikawa

Bulletin of the American Physical Society, DFD 2018　63　(13)　341　2018/11
Flow-induced transport of a membrane protein on vesicle surface

K. Nakamura, T. Omori, T. Ishikawa

Bulletin of the American Physical Society, DFD 2018　63　(13)　205　2018/11
Drug Permeation Measurement through the Skin by using a Two-Photon Laser Induced Fluorescent Microscopy Peer-reviewed

Kenji Kikuchi, Shunsuke Shigeta, Keiko Tsuruta-Numayama, Takuji Ishikawa

8th International Conference on Fluid Mechanics (ICFM8)　S10BM0-04　2018/09
FLUID-STRUCTURE INTERACTIONS OF NODAL CILIA AXONEME Peer-reviewed

Toshihiro Omori, Hiroto Sugai, Yohsuke Imai, Takuji Ishikawa

8th International Conference on Fluid Mechanics (ICFM8)　S10BM0-04　2018/09
A NUMERICAL SIMULATION OFSWIMMING SPERMATOZOA Peer-reviewed

N. Taketoshi, T. Omori, T. Ishikawa

8th International Conference on Fluid Mechanics (ICFM8)　S10BM0-02　2018/09
Behavior of motile unicellular alga flowing in a microchannel Peer-reviewed

Cheng-Hsi Chuang, Kenji Kikuchi, Azusa Kage, Takuji Ishikawa

8th International Conference on Fluid Mechanics (ICFM8)　S10BM0-01　2018/09
Locomotion mechanism of microcapsele using flow oscillation

Takeru Morita, Toshihiro Omori, Takuji Ishikawa

The Seven International Symposium on Aero Aqua Bio-mechanisms ISABMEC 2018　44　2018/09
Gut Bacterial Flow in Zebrafish Larva

Masahiro Takahashi, Kenji Kikuchi, Keiko Numayama-Tsuruta, Takuji Ishikawa

26　2018/08
Spatial heterogeneity of bacterial flora in the intestine of zebrafish larvae

Jinyou Yang, Yuji Shimogonya, Takuji Ishikawa

8th World Congress of Biomechanics　P2051　2018/07
Computational study of the nodal flow with a small number of cilia: comparison of mechanosensing and vesicle transport hypotheses

Toshihiro Omori, Kyosuke Shinohara, Hiroshi Hamada, Takuji Ishikawa

8th World Congress of Biomechanics　O0636　2018/07
Biomechanics can provide a new perspective on microbiology Invited

Takuji Ishikawa

8th World Congress of Biomechanics　Plen04　2018/07
FILTRATION FLOW BY CHOANOFLAGELLATE CHAMBERS OF FRESH-WATER SPONGES

K. Kikuchi, H. Maleprade, R. E. Goldstein, T. Ishikawa

18th International Symposium on Flow Visualization　11.1.1　2018/06
Anomalous swimming of a ciliary microorganism adjacent to wall

Takuya Ohmura, Yukinori Nishigami, Junichi Manabe, Takuji Ishikawa, Masatoshi Ichikawa

APS March Meeting 2018, Abstract　K46.00001　2018/03
「細胞スケールの流れ」の研究動向

石川拓司

日本機械学会誌　120　(1182)　26-31　2017/05/05
胃内部の固体粒子挙動の数値計算

石田駿一, 今井陽介, 宮川泰明, 石川拓司

バイオエンジニアリング講演会講演論文集(CD-ROM)　29th　2017

ISSN： 2424-2829
1C46 Numerical simulation of a swimming ciliate near a water-air or a water-wall interface

MANABE Junichi, OMORI Toshihiro, IMAI Yohsuke, ISHIKAWA Takuji

2016　(28)　"1C46-1"-"1C46-5"　2016/01/09
Publisher: The Japan Society of Mechanical Engineers

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Swimming behavior of microorganism near an interface is important to understand how to prevent bio-film formation, which can be a cause of medical instrument pollution. Recently, we found that a ciliate can be trapped at a water-air interface, though swims away from a water-wall interface. We conducted numerical simulation of swimming microorganism near an interface from hydrodynamic perspective, to reveal the entrapment mechanism. By mimicking microorganism shape in detail, our microorganism model reproduced entrapment phenomena for the first time in the world. We concluded that shape of a ciliate dominates the entrapment phenomena.
1E11 Numerical simulation of cell adhesion in microchannels

TAKEISHI Naoki, IMAI Yohsuke, YAMAGUCHI Takami, Kamm Roger D., ISHIKAWA Takuji

2016　(28)　"1E11-1"-"1E11-5"　2016/01/09
Publisher: The Japan Society of Mechanical Engineers

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We numerically investigate the velocity of an adherent cell in various sizes of microchannels. The velocity drastically decreases as decreasing the size of microchannels. When the channel size becomes smaller, the motion of the adherent cell changes from a "rolling motion" to a "bullet motion", where the cell rotates on side wall in rolling motion, while the cell adhere its circular arc to the wall in bullet motion. Larger adhesion force is generated in rear parts of rolling cell, and existed bonds experience rupturing with higher probability because of slip bond. Because cell cannot move forward unless the ligand-receptor bonds in rear parts rupture, frequent rupturing allows the rolling cell to move faster than the cell exhibiting bullet motion. As getting smaller in channel diameter, the surface area attached to the wall is larger and then the number of ligand-receptor bonds is larger for smaller microchannels, resulting in a lower velocity. Our numerical model allows us to investigate the effect of various parameters on adherent cell velocity.
1C45 A Numerical Simulation of Sperm Cell Locomotion in Shear Flow

OMORI Toshihiro, ISHIKAWA Takuji

2016　(28)　"1C45-1"-"1C45-3"　2016/01/09
Publisher: The Japan Society of Mechanical Engineers

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A sperm cell is a flagellated cell and it can swim in a fluid by beating flagellum. Locomotion of a sperm cell is strongly affected by surrounding fluid flow, and recently rheotaxis of sperm cells was found experimentally. Fluid mechanics then becomes a subject of growing importance in sperm motility. In this study, we numerically investigate sperm cell behavior in shear flow near a plane wall to quantitatively understand how fluid mechanics affects on swimming of sperm cell. Due to the small size of sperm cells, inertia effects of fluid motion can be neglected and we assume Stokes flow around the cell. Flow field is then expressed by boundary integral equation and which is solved by a boundary element method. As a result, the sperm cell shows reorient to upstream and keeps on swimming against the fluid flow. This result suggests that fluid mechanics plays a key role in navigation of sperm cells towards the ovum, which is located upstream in the oviduct.
195 Numerical simulation of a sperm cell swimming in a viscoelastic fluid

SHIMOMURA Eisaku, OMORI Toshihiro, IMAI Yhosuke, ISHIKAWA Takuji

2016　(51)　187-188　2016
Publisher: The Japan Society of Mechanical Engineers
197 Measurement of the behavior of cancer cells cultivated on a collagen gel

Iwasaki Yuwa, Imai Yohsuke, Kikuchi Kenji, Numayama-Tsuruta Keiko, Shigeta Shunsuke, Ishikawa Takuji

The Proceedings of Conference of Tohoku Branch　2016　(0)　191-192　2016
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmeth.2016.51.191 　
201 Real Time Visualization of Intestinal Peristalsis of the Zebrafish

NOH Hyeongtak, KIKUCHI Kenji, NUMAYAMA Keiko, ISHIKAWA Takuji

The Proceedings of Conference of Tohoku Branch　2016　(0)　199-200　2016
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmeth.2016.51.199 　
PS8-14 Visualization of intestinal peristalsis of mosquito midgut by using micro X-ray imaging(PS8: Poster Short Presentation VIII,Poster Session)

Kikuchi Kenji, Imai Yohsuke, Numayama-Tsuruta Keiko, Yamaguchi Takami, Ishikawa Takuji

Proceedings of the ... Asian Pacific Conference on Biomechanics : emerging science and technology in biomechanics　2015　(8)　365-365　2015/09/16
Publisher: The Japan Society of Mechanical Engineers
PS1-9 Noninvasive Measurement of Drug Permeation in the Skin(PS1: Poster Short Presentation I,Poster Session)

Shigeta Shunsuke, Kikuchi Kenji, Numayama Keiko, Ishikawa Takuji

Proceedings of the ... Asian Pacific Conference on Biomechanics : emerging science and technology in biomechanics　2015　(8)　230-230　2015/09/16
Publisher: The Japan Society of Mechanical Engineers
循環器のバイオメカニクス

石川拓司

日本機械学会誌　118　14　2015/08/01
微小生物流れ

石川拓司

日本機械学会誌　118　31　2015/08/01
クラミドモナスの鞭毛は上向きトルク発生に寄与する Invited

鹿毛あずさ, 菊地謙次, 石川拓司

京都大学数理解析研究所講究録　1940　110-111　2015/04
1A15 A numerical simulation of rolling and adhesion of red blood cells infected by malaria

ICHIKAWA Yuki, IMAI Yohsuke, MATSUNAGA Daiki, NIX Stephanie, ISHIKAWA Takuji, YAMAGUCHI Takami

2015　(27)　11-12　2015/01/08
Publisher: The Japan Society of Mechanical Engineers
1A16 Numerical Simulation of the Nodal Ciliary Motion Driven by the Dynein Motor Protein

SUGAI Hiroto, Omori Toshihiro, IMAI Yohsuke, ISHIKAWA Takuji

2015　(27)　13-14　2015/01/08
Publisher: The Japan Society of Mechanical Engineers
1A12 Behavior of tracer particles in capsule suspensions : the effect of size of tracer particles

ITO Hiroki, IMAI Yohsuke, MATSUNAGA Daiki, Omori Toshihiro, YAMAGUCHI Takami, ISHIKAWA Takuji

2015　(27)　5-6　2015/01/08
Publisher: The Japan Society of Mechanical Engineers
胃内のせん断応力の数値解析

宮川泰明, 今井陽介, 石田駿一, 山口隆美, 石川拓司

バイオエンジニアリング講演会講演論文集　27th　2015

ISSN： 1348-2920
胃内容物攪拌の数値計算:胃壁の運動の影響

宮川泰明, 今井陽介, 石田駿一, 山口隆美, 石川拓司

計算工学講演会論文集(CD-ROM)　20　2015

ISSN： 1342-145X
22pBL-8 Synchronized oscillation in a model of three nodal cilia with hydrodynamic interaction

Okumura K, Nishikawa S, Omori T, Ishikawa T, Takamatsu A

Meeting Abstracts of the Physical Society of Japan　70　(0)　3030-3030　2015
Publisher: The Physical Society of Japan
DOI： 10.11316/jpsgaiyo.70.1.0_3030 　

ISSN： 2189-079X
2B35 Effect of aeration on the distribution of Chlamydomonas

NONAKA Yuki, KIKUCHI Kenji, NUMAYAMA-TSURUTA Keiko, KAGE Azusa, UENO Hironori, ISHIKAWA Takuji

The Proceedings of the Bioengineering Conference Annual Meeting of BED/JSME　2015　(0)　371-372　2015
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmebio.2015.27.371 　
2B41 Effect of Rheological Properties on Ciliary motion and Flow in the airway

HAGA Tomofumi, KIKUCHI Kenji, UENO Hironori, NUMAYAMA Keiko, YAMAGUCHI Takami, ISHIKAWA Takuji

The Proceedings of the Bioengineering Conference Annual Meeting of BED/JSME　2015　(0)　373-374　2015
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmebio.2015.27.373 　
1316 Flow on a ciliary respiratory epithelium

HAGA Tomofumi, KIKUCHI Kenji, UENO Hironori, NUMAYAMA Keiko, YAMAGUCHI Takami, ISHIKAWA Takuji

The Proceedings of the Fluids engineering conference　2015　(0)　_1316-1_-_1316-2_　2015
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmefed.2015._1316-1_ 　

ISSN： 1348-0251

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We have studied experimentally about the flow on a ciliary respiratory epithelium with the relation between a viscosity of mucus and a generated flow velocity using μPTV measurement. We used a fresh dissected mouse respiratory epithelium for our experiment, and observed a flow on it by using a confocal microscopy for tracing micro fluorescent particles, which dispersed in the mucus on the ciliary cells. The frequency of ciliary motions and velocity of mucus were measured in several cases with different viscosity of mucus. The driven force for generating ciliary flow has a non-linearity with an increasing of viscosity. Our findings would play a medical role to clarify a mechanism of mucus flow on a ciliary respiratory epithelium with its viscous changing.
J0260202 Dispersion of red blood cells in a micro channel

CHENG-HSI Chuang, KIKUCHI Kenji, NUMAYAMA Keiko, YAMAGUCHI Takami, ISHIKAWA Takuji

The Proceedings of Mechanical Engineering Congress, Japan　2015　(0)　_J0260202--_J0260202-　2015
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmemecj.2015._J0260202- 　

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We have been focused on the dispersion of cells in micro channel flow, especially red blood cells (RBCs). When RBCs are dispersed in a micro channel with a Y-shape junction, the dispersion of cells would occur from denser to thinner direction according with concentration of cells. It is regarding to clarify the dispersion phenomena in micro channel for designing of lab-on-a-chip applications. The detailed mechanism of cell dispersion, however, has not been fully clarified yet. We performed the quantitative dispersion measurement in the Y-shape micro channel, in which two layers with and without RBCs flow in parallel, and investigated the effects of flow rates and hematocrit. Our results suggest that the dispersion in micro channel would be more dominant than Brownian diffusion, and depends on the hematocrit and the flow rate. These findings provide us useful information on mass transport in cell suspensions.
A104 Behavior of Yorticella in shear flow

YOSHIDA Naoto, KIKUCHI Kenji, KAGE Azusa, NUMAYAMA Keiko, NAGAI Moeto, ISHIKAWA Takuji

The Proceedings of the JSME Conference on Frontiers in Bioengineering　2015　(0)　7-8　2015
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmebiofro.2015.26.7 　

ISSN： 1348-2939
A108 Drug concentration measurement in a skin using two-photon microscopy

SHIGETA Shunsuke, KIKUCHI Kenji, NUMAYAMA Keiko, ISHIKAWA Takuji

The Proceedings of the JSME Conference on Frontiers in Bioengineering　2015　(0)　15-16　2015
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmebiofro.2015.26.15 　

ISSN： 1348-2939
A112 Numerical Simulation of the Ciliary Motion Driven by the Motor Protein

SUGAI Hiroto, OMORI Toshihiro, IMAI Yohsuke, ISHIKAWA Takuji

Proceedings of the ... JSME Conference on Frontiers in Bioengineering　2014　(25)　21-22　2014/10/02
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-2939
A111 A numerical simulation of a microorganism behavior near an interface

Manabe Junichi, Kyouya Kouhei, Omori Toshihiro, Imai Yohsuke, Ishikawa Takuji

Proceedings of the ... JSME Conference on Frontiers in Bioengineering　2014　(25)　19-20　2014/10/02
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-2939
動物のからだの左右を決める回転繊毛間の流体相互作用 (生物流体力学における流れ構造の解析と役割)

高松敦子, 石川拓司, 篠原恭介, 濱田博司

数理解析研究所講究録　1900　97-104　2014/06
Publisher: 京都大学
ISSN： 1880-2818
Bottom-up Approaches in Biological Flow Studies

ISHIKAWA Takuji

2014　(89)　"8-5"-"8-8"　2014/03/18
Publisher: The Japan Society of Mechanical Engineers
27aAD-4 Decoherence in an isolated system and the disappearance of quantum multiverse

Ishikawa Takuji

Meeting abstracts of the Physical Society of Japan　69　(1)　285-285　2014/03/05
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
2G34 A simulation of nutrient uptake in a suspension of squirmers

KAJIKI Shunsuke, IMAI Yohsuke, Yamaguchi Takami, Ishikawa Takuji

2014　(26)　539-540　2014/01/10
Publisher: The Japan Society of Mechanical Engineers
1G43 A numerical simulation of the cytoadhesion of malaria-infected red blood cells using a ligand-receptor interaction model

AMI Akihisa, IMAI Yohsuke, ISHIKAWA Takuji, YAMAGUCHI Takami

2014　(26)　245-246　2014/01/10
Publisher: The Japan Society of Mechanical Engineers
1G44 A numerical analysis of the behavior of cancer cells related to hematogenous metastasis in microvasculature

TAKEISHI Naoki, IMAI Yohsuke, YAMAGUCHI Takami, ISHIKAWA Takuji

2014　(26)　247-248　2014/01/10
Publisher: The Japan Society of Mechanical Engineers
1G33 A numerical simulation of motion of food in the stomach

MIYAGAWA Taimei, IMAI Yohsuke, YAMAGUCHI Takami, ISHIKAWA Takuji

2014　(26)　235-236　2014/01/10
Publisher: The Japan Society of Mechanical Engineers
2E15 Numerical analysis of a red blood cell flowing through a micro flow channel

OMORI Toshihiro, ISHIKAWA Takuji, IMAI Yohsuke, YAMAGUCHI Takami

2014　(26)　439-440　2014/01/10
Publisher: The Japan Society of Mechanical Engineers
2E22 Mechanism of the non-linear response of viscosity to volume fraction in dense capsule suspension

MATSUNAGA Daiki, IMAI Yohsuke, YAMAGUCHI Takami, ISHIKAWA Takuji

2014　(26)　445-446　2014/01/10
Publisher: The Japan Society of Mechanical Engineers
2E21 A numerical simulation of capsule behavior in a near-wall shear flow

Nix Stephanie, IMAI Yohsuke, MATSUNAGA Daiki, YAMAGUCHI Takami, ISHIKAWA Takuji

2014　(26)　443-444　2014/01/10
Publisher: The Japan Society of Mechanical Engineers
J0220101 Effect of aeration on the distribution of micro algae cells

NONAKA Yuki, UENO Hironori, NUMAYAMA-TSURUTA Keiko, KIKUCHI Kenji, ISHIKAWA Takuji

The Proceedings of Mechanical Engineering Congress, Japan　2014　(0)　_J0220101--_J0220101-　2014
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmemecj.2014._J0220101- 　

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When culturing microalgae, we often use aeration for mixing the culture fluid. However, it is not clear how microalgae and aeration interact each other. In order to understand transport phenomena in a microalgae suspension, it is important to clarify the distribution of cells in a container. In this study, we visualized the distribution of microalgae in a tube container with aeration. In the case without aeration, we observed the bioconvection with chaotic pattern. In the case with aeration, on the other hand, we observed cells aggregated in specific regions.
J027014 Simulation of nutrient uptake by swimming microorganisms in a suspension

KAJIKI Shunsuke, IMAI Yohsuke, YAMAGUCHI Takami, ISHIKAWA Takuji

Mechanical Engineering Congress, Japan　2013　"J027014-1"-"J027014-4"　2013/09/08
Publisher: The Japan Society of Mechanical Engineers

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Little is known about the mass transport in microbial suspension in previous studies. The aim of this study is to analyze the effect of the swimming motion on the nutrient uptake. We modeled a microorganism as a squirmer and calculated its locomotion by boundary element method . Moreover we simulated the nutrient uptake by tracking nutrient particles. The results show that the nutrient uptake is strongly affected by the swimming mode of a microorganism.
J027011 A Numerical Simulation of Collective Swimming of Microorganisms

KYOYA Kohei, MATSUNAGA Daiki, IMAI Yohsuke, YAMAGUCHI Takami, ISHIKAWA Takuji

Mechanical Engineering Congress, Japan　2013　"J027011-1"-"J027011-4"　2013/09/08
Publisher: The Japan Society of Mechanical Engineers

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Microorganisms play a vital role in many biological, medical and engineering phenomena. Some recent research efforts have demonstrated the importance of biomechanics in understanding certain aspects of microorganism behaviors such as locomotion and collective motions of cells. Previous studies had problems of high computational load in simulating many-body interaction of swimmers. In this study, we propose a boundary element method, based on the double-layer representation, for calculating interactions of many-body swimmers in Stokes flow regime. We use Graphic Processing Unit (GPU) to speed up the computation. We then analyze interactions of 100 swimmers.
2B14 Rheological analysis of capsule suspension using boundary element method

MATSUNAGA Daiki, IMAI Yohsuke, ISHIKAWA Takuji, Yamaguchi Takami

2013　(25)　299-300　2013/01/08
Publisher: The Japan Society of Mechanical Engineers
2E02 Analysis of Red Blood Cell Behavior in a Narrow Tube

HOSAKA Haruki, OMORI Toshihiro, IMAI Yohsuke, ISHIKAWA Takuji, YAMAGUCHI Takami

2013　(25)　387-388　2013/01/08
Publisher: The Japan Society of Mechanical Engineers
2B19 A numerical analysis of the cell migration in microcirculatory blood flow

TAKEISHI Naoki, IMAI Yohsuke, NAKAAKI Keita, ISHIKAWA Takuji, Yamaguchi Takami

2013　(25)　307-308　2013/01/08
Publisher: The Japan Society of Mechanical Engineers
1D04 Numerical analysis of swimming model microorganisms by GPU

KYOYA Kohei, MATSUNAGA Daiki, IMAI Yohsuke, YAMAGUCHI Takami, ISHIKAWA Takuji

2013　(25)　117-118　2013/01/08
Publisher: The Japan Society of Mechanical Engineers
1D01 3D-PTV measurement of the phototactic movement of algae in the shear flow

MAEDA Tatsuyuki, ISHIKAWA Takuji, UENO Hironori, NUMAYAMA-TSURUTA Keiko, IMAI Yosuke, YAMAGUCHI Takami

The Proceedings of the Bioengineering Conference Annual Meeting of BED/JSME　2013　(0)　111-112　2013
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmebio.2013.25.111 　
3E15 Measurement of ciliary flow generated on the surface of tracheal lumen

KIYOTA Koki, UENO Hironori, ISHIKAWA Takuji, NUMAYAMA Keiko, IMAI Yohsuke, OMORI Toshihiro, YAMAGUCHI Takami

The Proceedings of the Bioengineering Conference Annual Meeting of BED/JSME　2013　(0)　609-610　2013
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmebio.2013.25.609 　
J027013 Effect of aeration on the bio-convection of micro algae cells

NONAKA Yuki, UENO Hironori, NUMAYAMA Keiko, OMORI Toshihiro, IMAI Yohsuke, YAMAGUCHI Takami, ISHIKAWA Takuji

The Proceedings of Mechanical Engineering Congress, Japan　2013　(0)　_J027013-1-_J027013-4　2013
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmemecj.2013._J027013-1 　

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Bioconvection patterns are often observed in microalgae suspensions of randomly, but on average upwardly, swimming microalgae which are little denser than water. When we culture microalgae in the laboratory, we usually add aeration for mixing the culture fluid and supplying oxygen and carbon dioxide. However, the effect of aeration on the bioconvection pattern and the transport phenomena in the suspension is unclear. In this study, we investigated bioconvection pattern in a suspension of Chlamydomonas reinhardtii under the condition with aeration. Bioconvection pattern in a cylindrical container was visualized by red illumination, and white light for phototaxis could be added from above. Small bubbles were injected by a needle connected to a syringe. Observation of bioconvection patterns of microalgae suspension with aeration showed three kinds of flow patterns depending on the bubble flow rate. When there was no bubble flow, conventional bioconvection was dominant. When flow rate was low, observed pattern in the cylindrical container was split into two flow regions, where the bioconvection and the bubble flow were dominant respectively. When flow rate was high, bubble flow became dominant and no clear bioconvection was observed. Such changes in the bioconvection pattern have not been reported before. These findings are important to understand the transport phenomena in algae suspensions in engineering settings.
C107 Bioconvection of micro algae cells under an aeration condition

NONAKA Yuki, UENO Hirinori, NUMAYAMA Keiko, OMORI Toshihiro, IMAI Yosuke, YAMAGUCHI Takami, ISHIKAWA Takuji

The Proceedings of the JSME Conference on Frontiers in Bioengineering　2013　(0)　45-46　2013
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmebiofro.2013.24.45 　

ISSN： 1348-2939
103 Aggregation structure of algae in forced circulation bubbly flow

NONAKA Yuki, UENO Hironori, NUMAYAMA-TSURUTA Keiko, OMORI Toshihiro, IMAI Yosuke, YAMAGUCHI Takami, ISHIKAWA Takuji

The Proceedings of Conference of Tohoku Branch　2013　(0)　10-11　2013
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmeth.2013.48.10 　
計算生体力学シミュレーションによるミクロからマクロスケールの生体機能の解析

山口隆美, 今井陽介, 水野文雄, 大森俊宏, 上野裕則, 沼山恵子, 石川拓司

バイオメカニズム学術講演会予稿集　33回　33-34　2012/12
Publisher: バイオメカニズム学会
806 Numerical simulation of dynamics of solid particles in the stomach

MIYAGAWA Taimei, IMAI Yohsuke, ISHIKAWA Takuji, YAMAGUCHI Takami

The Computational Mechanics Conference　2012　(25)　9-10　2012/10/06
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-026X
807 Numerical analysis of swimming model microorganisms by a boundary element method based on the double-layer representation

KYOYA Kohei, MATSUNAGA Daiki, IMAI Yohsuke, YAMAGUCHI Takami, ISHIKAWA Takuji

The Computational Mechanics Conference　2012　(25)　11-12　2012/10/06
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-026X
803 Numerical simulation of adhesive phenomena of Pf-T-IRBC and the endothelial cells

AMI Akihisa, IMAI Yohsuke, NAKAAKI Keita, ISHIKAWA Takuji, YAMAGUCHI Takami

The Computational Mechanics Conference　2012　(25)　3-4　2012/10/06
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-026X
ストークス流れ中の非球形カプセルの配向現象

石川拓司, 大森俊宏, 今井陽介, 山口隆美

京都大学数理解析研究所講究録　(1808)　121-126　2012/09/01
111 Simulation of mass absorption of swimming model microorganisms by a boundary element method

KAJIKI Shunsuke, MATSUNAGA Daiki, IMAI Yohsuke, YAMAGUCHI Takami, ISHIKAWA Takuji

2012　(47)　28-29　2012/03/13
Publisher: The Japan Society of Mechanical Engineers
110 Numerical analysis of swimming model microorganisms by a boundary element method

Kyoya Kohei, MATSUNAGA Daiki, IMAI Yohsuke, YAMAGUCHI Takami, ISHIKAWA Takuji

2012　(47)　26-27　2012/03/13
Publisher: The Japan Society of Mechanical Engineers
113 Numerical analysis of adhesive phenomena of malaria-infected red blood cells

AMI Akihisa, IMAI Yohsuke, NAKAAKI Keita, ISHIKAWA Takuji, YAMAGUCHI Takami

2012　(47)　32-33　2012/03/13
Publisher: The Japan Society of Mechanical Engineers
109 Analysis of Red Blood Ce11 Deformation in Flow Field Using a Boundary Element Method

Hosaka Haruki, Ishikawa Takuji, Omori Toshihiro, Imai Yohsuke, Yamaguchi Takami

2012　(47)　24-25　2012/03/13
Publisher: The Japan Society of Mechanical Engineers
212 Development of a numerical model for blood flow in microvessels using GPGPU computing

Takeishi Naoki, IMAI Yohsuke, NAKAAKI Keita, ISHIKAWA Takuji, YAMAGUCHI Takami

2012　(47)　230-231　2012/03/13
Publisher: The Japan Society of Mechanical Engineers
第5回青葉工学振興会賞細胞レベルから構築した微生物サスペンジョン力学の創生

石川拓司

翠巒　(28)　3　2012/03/02
生命現象の予測を目指して

石川拓司

青葉工業会ニュース　(50)　17　2012/03/02
細胞レベルから構築した微生物サスペンジョン力学による藻類の分布予測モデルの革新

石川拓司

東北大学機械系同窓会ニュース　(17)　2　2012/03/01
8F34 Development of a numerical model of microcirculatory blood flow in malaria infection based on GPU

NAKAAKI Keita, IMAI Yohsuke, ISHIKAWA Takuji, Lim Chwee Teck, YAMAGUCHI Takami

2012　(24)　"8F34-1"-"8F34-2"　2012/01/06
Publisher: The Japan Society of Mechanical Engineers
8F13 Development of a GPU computing platform for accurate simulations of large-scale cellular flow

IMAI Yohsuke, MATSUNAGA Daiki, ISHIKAWA Takuji, YAMAGUCHI Takami

2012　(24)　"8F13-1"-"8F13-2"　2012/01/06
Publisher: The Japan Society of Mechanical Engineers
7H22 A fast simulation of pulmonary airflow and inhaled particles by GPU

IMAI Yohsuke, MIKI Takahito, ISHIKAWA Takuji, YAMAGUCHI Takami

2012　(24)　"7H22-1"-"7H22-2"　2012/01/06
Publisher: The Japan Society of Mechanical Engineers
固体成分を含む胃内容物の攪拌の数値シミュレーション

宮川泰明, 今井陽介, 小林生馬, 石川拓司, 山口隆美

日本機械学会東北支部総会・講演会講演論文集　47th　2012
胃内部の固体粒子運動の数値シミュレーション

宮川泰明, 今井陽介, 石川拓司, 山口隆美

日本機械学会計算力学講演会論文集(CD-ROM)　25th　2012

ISSN： 2424-2799
2306 A numerical computation on gastric mixing

KOBAYASHI Ikuma, IMAI Yohsuke, ISHIDA Shunichi, ISHIKAWA Takuji, YAMAGUCHI Takami

The Computational Mechanics Conference　2011　(24)　642-643　2011/10/08
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-026X
2305 Numerical simulation of swallowing based on videofluorography

ISHIDA Shunichi, IMAI Yohsuke, ISHIKAWA Takuji, KINJO Aki, MATSUKI Noriaki, YAMAGUCHI Takami

The Computational Mechanics Conference　2011　(24)　639-641　2011/10/08
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-026X
2308 A fast simulation of capsule motion in flow by GPU computing

IMAI Yohsuke, MATSUNAGA Daiki, ISHIKAWA Takuji, YAMAGUCHI Takami

The Computational Mechanics Conference　2011　(24)　646-647　2011/10/08
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-026X
2307 Development of GPU simulation of microcirculatory blood flow

NAKAAKI Keita, IMAI Yohsuke, ISHIKAWA Takuji, Lim Chwee Teck, YAMAGUCHI Takami

The Computational Mechanics Conference　2011　(24)　644-645　2011/10/08
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-026X
B112 Development of GPU computing method for capsule suspension

MATSUNAGA Daiki, IMAI Yohsuke, OMORI Toshihiro, MIKI Takahito, ISHIKAWA Takuji, YAMAGUCHI Takami

Proceedings of the ... JSME Conference on Frontiers in Bioengineering　2011　(22)　61-62　2011/10/06
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-2939
Preface : For the “Joint Issue of JSME (Japan Society of Mechanical Engineers) and KSB (Korean Society of Biomechanics)”

S. Park, K. Rhee, T. Ishikawa

Journal of Biomechanical Science and Engineering　6　in press　2011/07
Preface : For the “Subject Issue on Biofluid and Biothermal Engineering”

T. Ishikawa

Journal of Biomechanical Science and Engineering　6　63　2011/04
184 Numerical simulation of red blood cell flow in micro vessels : effects of endothelial cell geometry

FUJIWARA Masaki, IMAI Yohsuke, NAKAAKI Keita, ISHIKAWA Takuji, YAMAGUCHI Takami

2011　(46)　170-171　2011/03/15
Publisher: The Japan Society of Mechanical Engineers
9J-07 Analysis of cancer cell membrane protein movement by confocal PTV system

YOSHIMOTO Takefumi, ISHIKAWA Takuji, NUMAYAMA Keiko, MATSUKI Noriaki, TANAKA Tatsuya, UENO Hironori, IMAI Yohsuke, YAMAGUCHI Takami

The Proceedings of the Bioengineering Conference Annual Meeting of BED/JSME　2010　(0)　487-488　2011
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmebio.2010.23.487 　
187 Flow measurement of bacterial suspensions in a tube by a confocal micro-PIV system

MAEDA Tatsuyuki, ISHIKAWA Takuji, NUMAYAMA Keiko, IMAI Yosuke, UENO Hironori, YAMAGUCHI Takami

The Proceedings of Conference of Tohoku Branch　2011　(0)　176-177　2011
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmeth.2011.46.176 　
流れを見る ― 細胞周りの流れの共焦点マイクロPIV計測 ―

石川拓司

生物の科学遺伝　64　78-84　2010/11
論文・論説賞：「次世代医療関連産業中核人材育成のための実践的教育システム」の開発と実証研究

山野真裕, 松木範明, 沼山恵子, 武田元博, 早坂智明, 石川拓司, 山口隆美

工学教育　58　21-22　2010/11
21pEC-7 Suspension Dynamics of swimming microorganisms

Ishikawa Takuji

Meeting abstracts of the Physical Society of Japan　65　(1)　305-305　2010/03/01
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
Particle-Based Methods for Multiscale Modeling of Blood Flow in the Circulation and in Devices: Challenges and Future Directions Peer-reviewed

Takami Yamaguchi, Takuji Ishikawa, Y. Imai, N. Matsuki, Mikhail Xenos, Yuefan Deng, Danny Bluestein

ANNALS OF BIOMEDICAL ENGINEERING　38　(3)　1225-1235　2010/03

DOI： 10.1007/s10439-010-9904-x 　

ISSN： 0090-6964
B210 Development of a micro fluidic device to sort circulating tumor cells from a blood sample

TANAKA Tatsuya, ISHIKAWA Takuji, MATSUKI Noriaki, IMAI Yohsuke, UENO Hironori, NUMAYAMA-TSURUTA Keiko, YAMAGUCHI Takami

The Proceedings of the JSME Conference on Frontiers in Bioengineering　2010　(0)　105-106　2010
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmebiofro.2010.21.105 　

ISSN： 1348-2939
1409 Shear-induced fluid-tracer diffusion in a semidilute suspension of spheres

Ishikawa Takuji, Yamaguchi Takami

Fluids engineering conference ...　2009　443-444　2009/11/06
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-2882

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We calculated tracer diffusion in a sheared suspension of non-Brownian rigid spheres and propose a new numerical method based on a boundary element method and Stokesian dynamics method. We present details of the numerical method and examine the accuracy of the method. The limitation of semi-diluteness is due to the accuracy of tracer velocity calculation. The results show that the diffusivity of fluid tracers is greater than that of suspended spheres in the semi-dilute regime. The diffusivity of velocity gradient direction is about threefold greater than that in the vorticity direction. Simple scaling demonstrates that the diffusivity of fluid tracers increases with the square of the volume fraction of spheres in the semi-dilute regime, which is confirmed numerically.
変形機構を有する室内飛行船の開発

広瀬量平, 今井陽介, 石川拓司, 山口隆美

ブイヤント航空　37　81-88　2009/10
2201 Biomechanics of suspensions of micro-organisms

Ishikawa Takuji

The Computational Mechanics Conference　2007　(20)　407-408　2007/11/25
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-026X
303 Application of a High-Order AMR Method to Pulmonary Airflow Simulations

IMAI Yohsuke, MIKI Takahito, ISHIKAWA Takuji, NAKAMURA Masanori, WADA Shigeo, YAMAGUCHI Takami

The Computational Mechanics Conference　2007　(20)　583-584　2007/11/25
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-026X
瀬口賞を受賞して

石川拓司

Bioengineering News　36　17　2007/09/01
微生物の濃厚溶液の数値シミュレーション

石川拓司

計算数理工学レビュー　2007-2　41-46　2007/09/01
Preface : Special Issue on Cardiovascular Flow

T. Yamaguchi, T. Ishikawa

Journal of Biomechanical Science and Engineering　2　45　2007/05/01
27pSB-14 Study of Quantum Decoherence in a finite system : Three Schrodinger cats and the Nuclear collective motion

ISHIKAWA Takuji

Meeting abstracts of the Physical Society of Japan　62　(1)　47-47　2007/02/28
Publisher: The Physical Society of Japan (JPS)
ISSN： 1342-8349
331 Meso-scale structure in a concentrated suspension of micro-organisms

Ishikawa Takuji, Pedley T.J., Imai Yohsuke, Tsubota Ken-ichi, Yamaguchi Takami

2006　(19)　318-319　2007/01/06
Publisher: The Japan Society of Mechanical Engineers
Interference of Fire Smoke between Successive Tunnels with a Snow-Shed

Kawabata Nobuyoshi, Sano Akinori, Kikumoto Tomoki, Ishikawa Takuji, Sato Tadao, Kanou Tatuo

Transactions of the Society of Heating,Air-conditioning and Sanitary Engineers of Japan　29　(94)　61-68　2004
Publisher: 公益社団法人空気調和・衛生工学会
DOI： 10.18948/shase.29.94_61 　

ISSN： 0385-275X

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When a fire accident occurs in the upstream tunnel of successive tunnels connected by a Snow-Shed, it is necessary to control the ventilation so that damage does not expand by smoke flowing downstream. We analyze this phenomenon by means of a three-dimensional simulator using Large Eddy Simulation to examine the interference between successive tunnels, and defined the interference rate I as the ratio of smoke densities in successive tunnels. From comparisons between simulation results and experimental results we confirmed that the simulations have reasonable accuracy. In this way, the rate of interference of fire smoke between the two tunnels was almost in agreement. Many simulation results carried out under various conditions confirmed that the interference rate is governed by the Froude Number, the ratio of longitudinal ventilation velocities of the two tunnels, the dimensionless distance between the tunnels, and the inclination of the Snow-Shed. Each parameter was examined for its influence on the interference rate. Finally we derived the evaluation formula of the interference rate.
Numerical Simulation of Mixing Process of Gaseous Suppressant

Nobuyoshi Kawabata, Takuji Ishikawa, Yusuke Naito, Youichiro Matsumoto, Naoshi Saito, Takashi Tsuruda

Nippon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B　69　(688)　2569-2576　2003
Publisher: Japan Society of Mechanical Engineers
DOI： 10.1299/kikaib.69.2569 　

ISSN： 0387-5016
Secondary Flow of Viscoelastic Fluid due to a Rotating Disc Enclosed in a Cylindrical Casing

FUJIMOTO Masahiro, FUJITA Katushi, ISHIKAWA Takuji, KAWABATA Nobuyoshi

The Proceedings of Conference of Hokuriku-Shinetsu Branch　2003　(0)　95-96　2003
Publisher: The Japan Society of Mechanical Engineers
Microscopic Observation of Polymer Solution in Pipe Flow by Freeze-Drying Method

FUJITA Katsushi, ISHIKAWA Takuji, KAWABATA Nobuyoshi, HASHIMOTO Ryu, BABA Takaaki

The Proceedings of the Fluids engineering conference　2003　(0)　172-172　2003
Publisher: The Japan Society of Mechanical Engineers
ISSN： 1348-2882
Numerical analysis of poiseuille flow of polymeric liquid by means of a bead-spring macro model

Takuji Ishikawa, Nobuyoshi Kawabata, Hirohito Shimizu, Katsushi Fujita

Nippon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B　68　(676)　3266-3272　2002
Publisher: Japan Society of Mechanical Engineers
DOI： 10.1299/kikaib.68.3266 　

ISSN： 0387-5016
Simulation of Blood Flow in a Small Artery with Stenosis by means of DEM

ISIKAWA Takuji, KAWABATA Nobuyoshi, TACHIBANA Motoyoshi

The proceedings of the JSME annual meeting　2002　(0)　93-94　2002
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmemecjo.2002.6.0_93 　

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We have proposed a new method to model an erythrocyte by using drag points and springs as an altanative way to analyze a blood flow. In this paper, a blood flow in a small artery with stenosis is simulated by means of DEM. It is found that erythrocyte is strongly deformed around the stenosis and that the vortex downstream of stenosis weakened by erythrocytes.
Influence of the Obstacle on the Backlayering Characteristic of the Thermal Plume in a Tunnel

HAYASHI Takumi, KAWABATA Nobuyoshi, ISHIKAWA Takuji, MATSUMOTO Tetsuharu

The Proceedings of Conference of Hokuriku-Shinetsu Branch　2002　(0)　83-84　2002
Publisher: The Japan Society of Mechanical Engineers
Influence of the obstacle near the tunnel ceiling gives to the back layering characteristic of the thermal plume

MATSUMOTO Tetsuharu, KAWABATA Nobuyoshi, ISHIKAWA Takuji, OKUGAWA Shingou

The Proceedings of Conference of Hokuriku-Shinetsu Branch　2002　(0)　81-82　2002
Publisher: The Japan Society of Mechanical Engineers
Characteristics of Fire Fume in the Tunnel

SHIOJIMA Ken, KAWABATA Nobuyoshi, ISHIKAWA Takuji

The Proceedings of Conference of Hokuriku-Shinetsu Branch　2002　(0)　87-88　2002
Publisher: The Japan Society of Mechanical Engineers
Poiseuille Flow of Viscoelastic Fluids by Bead-Spring MacroModel

Shimizu Hirohito, ISHIKAWA Takuji, KAWABATA Nubuyoshi, fujita Katsusi

The Proceedings of Conference of Hokuriku-Shinetsu Branch　2002　(0)　95-96　2002
Publisher: The Japan Society of Mechanical Engineers
Evaluation of critical velocity employed to prevent the backlayering of thermal fume during tunnel fires

Qian Wang, Nobuyoshi Kawabata, Takuji Ishikawa

Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B　67　(656)　911-918　2001
Publisher: Japan Society of Mechanical Engineers
DOI： 10.1299/kikaib.67.911 　

ISSN： 0387-5016
Numerical analysis of blood flow under the oscillatory shear field by means of a bead-spring-damper Model

T. Ishikawa, N. Kawabata, M. Tachibana

Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B　67　(661)　2180-2187　2001
Publisher: Japan Society of Mechanical Engineers
DOI： 10.1299/kikaib.67.2180 　

ISSN： 0387-5016
1B12 Proposal of Simulation Method for a Blood Flow by means of a Deformable Erythrcyte Model

ISIKAWA Takuji, KAWABATA Nobuyoshi, TACHIBANA Motoyoshi

Proceedings of the JSME Bioengineering Conference and Seminar　2001　(0)　47-48　2001
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmebs.2001.12.0_47 　

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It is not appropriate to use constitutive equations for a blood now in a small artery because of the heterogeneity of the blood. In this paper, a new method to model an erythrocyte by using drag points and springs is proposed as an altanative way to analyze the blood flow. The progression process of this method and advantages are briefly dicribed. Finally, future view of this method is mentioned.
K-1034 Backlayering Velocity of the Thermal Plume Induced by Tunnel Fires

ISHIKAWA Masao, KAWABATA Nobuyoshi, ISHIKAWA Takuji, KUNIKANE Yuko

The proceedings of the JSME annual meeting　1　(0)　9-10　2001
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmemecjo.II.01.1.0_9 　

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It is important to clarify the basic characteristics, such as backlayering distance and velocity of the thermal plume generated by the fire accident in a road tunnel in order to design the ventilation system for securing the evacuate environment. In this research, the backlayering velocity and distance are investigated by the experiments which use a reduced scale model tunnel and by the large eddy simulation. The reliability of numerical code is verified by compareing numerical and experimental results. The results show that the backlayering velocity increases with increasing the heat release rate and that the backlayering velocity and distance decrease with increasing the ventilation velocity.
K-1035 Influence of Obstacle on Backlayering Characteristic of Thermal Plume in Model Tunnel

HAYASHI Takumi, KAWABATA Noboyoshi, ISHIKAWA Takkuji, MATSUMOTO Tetsuharu

The proceedings of the JSME annual meeting　1　(0)　11-12　2001
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmemecjo.II.01.1.0_11 　

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When a tunnel fire happens, the accident vehicle and other vehicles often exist around the fire source. These obstacles influence are exerted on the critical ventilation velocity of the thermal plume from backlaryering and the characteristics of the backlayering distance etc. Then, we install the obstacle in the 1/15 scale model tunnel, and the influence of the obstacle on the backlayering characteristic of the thermal plume was investigated experimentally and numerically
K-1036 Descent of Smoke Moving alone Ceiling at Tunnel Fire

YAMAMOTO Nobuyuki, KWABATA Nobuyoshi, ISHIKAWA Takuji, KUNIKANE Yuuko

The proceedings of the JSME annual meeting　1　(0)　13-14　2001
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmemecjo.II.01.1.0_13 　

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When the tunnel fire occurred, the damage by smoke and thermal plumes is considerable. The temperature of thermal plumes, which is stratified and moves along the ceiling, decreases because the ceiling gradually absorbs the heat from the thermal plume. The decrease of temperature induces the thermal plume and smoke descending towards the ground. Practically, in order to keep the evacuate environment, fire exits are installed with a certain interval. Therefore, in order to set up fire exit of appropriate interval, it is necessary to clarify the distance where smoke descends to the ground. Consequently, in this research, the influences of various parameters on the descent of smoke were examined by the 3D Large Eddy simulation.
K-1037 Interference of Ventilation between Two Tunnels connected by Snow Shed

SANO Akinori, KAWABATA Nobuyoshi, ISIKAWA Takuji

The proceedings of the JSME annual meeting　1　(0)　15-16　2001
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmemecjo.II.01.1.0_15 　

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If fire smoke is generated in the upstream successive tunnel by a traffic accident, the exhausted smoke flows into the downstream tunnel, which may destroy the evacuate environment in the downstream tunnel. It is, therefore, important to discuss the interference rate of successive tunnels. In this paper, the effect of variouse parameters on the interference rate is investigated by large eddy simulation. The reliability of numerical code is verified by comparing with the real scale tunnel experiment. Consequently, the interference rate is expressed by a new equation.
K-1038 Behavior of thermal plume at fire in curvature tunnel

KAWAI Tomoki, KAWABATA Noboyoshi, ISHIKAWA Takuji

The proceedings of the JSME annual meeting　1　(0)　17-18　2001
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmemecjo.II.01.1.0_17 　

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Recent year, traffic jam often occurs in the urban area. In the urban area, the highways are expected to be constructed under ground as a solution of the traffic jam. Such tunnels have large curvature in the junction area, however the behavior of thermal plume and critical velocity have not been clarified in case of fire accidents. In this research, a fire in the curvature tunnel was simulated, and the behavior of the thermal plume was discussed.
K-1039 Pressure drop at tunnel fire

ASABATAKE Kimihiro, KAWABATA Nobuyoshi, ISHIKAWA Takuji, SHIMOCHI Miyoshi, TOTTORI Hisaharu

The proceedings of the JSME annual meeting　1　(0)　19-20　2001
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmemecjo.II.01.1.0_19 　

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When tunnel fire occurs, pressure drops at the fire source by the expansion of the air. The strict pressure drop has not been estimated in the discussion of the tunnel ventilation in the emergency fires as yet. In this research, tunnel fires are simulated in one and three dimensionaly and the pressure drop is investigated. The effects of the fire scale and the ventilation velocity on the pressure drop by the fire is clarified.
K-1424 Shear Flow Characteristics of Polymer Solution by Bead-Spring Macro Model

SAKAMOTO Noriko, FUJITA Katushi, KAWABATA Nobuyoshi, ISHIKAWA Takuji

The proceedings of the JSME annual meeting　1　(0)　251-252　2001
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmemecjo.II.01.1.0_251 　

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The flow of viscoelastic fluid by means of a bead-spring macro model shows non-Newtonian viscosity. The shear flow characteristics of polymer solution are investigated experimentally by using by cone-plate type viscometer. The experimental results are compared with the numerical results by using bead-spring macro model, where three types of models (conventional modeling, present modeling, present modeling + random) are employed. The value and the equation of the spring constant are discussed so that the numerical results show good agreement with the experimental results. It is found that the present modeling + random can consistently express the distribution of polymer chains and the rheological property of viscoelastic fluids.
F-0812 Modeling of Blood Circulatory System by means of Bondgraph

SUGA Noriyoshi, ISHIKAWA Takuji, KAWABATA Nobuyoshi, TATIBANA Motoyoshi

The proceedings of the JSME annual meeting　1　(0)　23-24　2001
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmemecjo.IV.01.1.0_23 　

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It is difficult for highly accurate methods such as CFD to model all blood circulation of the human body. In this research, bondgraph is used in order to simply model the all blood circulation of the human body, bondgraph is the effective method to express complicated systems and the computational load is small. The heart, the artery, the capillary, and the vein of human body are modeled by the bondgraph, and the change of flow rate and pressure are discussed.
F-0824 Numerical Simulation of Pouseuille Flow of Blood by means of a Deformable Erythrcyte Model

SAWAZAKI Hiromasa, ISIKAWA Takuji, KAWABATA Nobuyoshi, TACHIBANA Motoyoshi

The proceedings of the JSME annual meeting　1　(0)　47-48　2001
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmemecjo.IV.01.1.0_47 　

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It is not appropriate to use constitutive equitions for small arteries because of the heterogeneity of the blood. In this paper, a new method to model an erythrocyte by using drag point s and springs is proposed as an altanative to analyze the blood flow. The behavior of erythrocytes is computed under Poiseuille flow. The rotating attitude of an erythrocyte under Poiseuille flow, shear-thinning property, first normal stress difference and plasma layer near the wall are discuassed.
Backlayering characteristics of thermal fume during tunnel fires in Hanshin Expressway

T Ishikawa, N Kawabata, H Tottori, M Ishida

10TH INTERNATIONAL SYMPOSIUM ON AERODYNAMICS AND VENTILATION OF VEHICLE TUNNELS　(43)　597-614　2000
Modeling of an erythrocyte by beads and springs and the numerical analysis of blood flow under the constant shear field

Takuji Ishikawa, Nobuyoshi Kawabata, Motoyoshi Tachibana

Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B　66　(650)　2642-2649　2000
Publisher: Japan Society of Mechanical Engineers
DOI： 10.1299/kikaib.66.650_2642 　

ISSN： 0387-5016
Fundamental characteristics of viscoelastic fluid modeled by beeds, springs and dampers (mechanism of second normal stress difference generation by dampers)

Takuji Ishikawa, Nobuyoshi Kawabata, Katsushi Fujita, Yutaka Miyake

Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B　66　(648)　2049-2055　2000
Publisher: Japan Society of Mechanical Engineers
DOI： 10.1299/kikaib.66.648_2049 　

ISSN： 0387-5016
Unsteady flow of viscoelastic fluid modeled by beeds, springs and dampers

Takuji Ishikawa, Nobuyoshi Kawabata, Katsushi Fujita, Yutaka Miyake

Nihon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B　66　(645)　1287-1294　2000
Publisher: Japan Society of Mechanical Engineers
DOI： 10.1299/kikaib.66.1287 　

ISSN： 0387-5016
Modeling of an Erythrocyte by Beads and Springs and the Numerical Analysis of Blood Flow under the Constant Shear Field

ISHIKAWA Takuji, KAWABATA Nobuyoshi, TACHIBANA Motoyoshi

The proceedings of the JSME annual meeting　2000　(0)　291-292　2000
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmemecjo.2000.1.0_291 　

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The blood flow in large arteries is commonly analyzed by means of the constitutive equations. However, it is not appropriate to use constitutive equations for small arteries because of the heterogeneity of the blood. In this paper, a new method to model an erythrocyte by using beads and springs is proposed as an alternative to analyze the blood flow. The behavior of a single erythrocyte is computed under a constant shear field. The results show that the bead-spring model appropriately can simulate the tank tread motion of an erythrocyte under a high shear field and stress thinning. It is therefore considered that the bead-spring erythrocyte model is able to consistently express blood characteristics
Gaseous Fire Suppression Equipment for a high aspect ratio space

AKINO Takashi, KAWABATA Nubuyoshi, ISHIKAWA Takuji, NAITO Yusuke, TANAKA Kazuhiro, SAKURAI Kenichi

The proceedings of the JSME annual meeting　2000　(0)　255-256　2000
Publisher: The Japan Society of Mechanical Engineers
DOI： 10.1299/jsmemecjo.2000.4.0_255 　

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Gaseous fire suppression equipment is able to extinguish fire without staining spread area and restore the room after the extinguishments early. So, application cases of this extinguishing system increase recently. The purpose of this study is to develop the simulator of gaseous fire extinguishing system that can consider the unsteady change using bond graph. In the case of the high-aspect-ratio space like parking lots, it is difficult to keep a uniform concentration in all area of the protection subdivision. However, the effect of the aspect ratio of protection subdivision is not considered in the conventional designs. Therefore, modeling by using of bond graph and examine the effects of aspect ratio are investigated.
214 Simulation of human erythrocyte motion in the constant shear field using a disk-spring model

SAWAZAKI Hiromasa, ISHIKAWA Takuji, KAWABATA Nobuyoshi, TATIBANA Motoyosi

The Proceedings of Conference of Hokuriku-Shinetsu Branch　2000　(0)　65-66　2000
Publisher: The Japan Society of Mechanical Engineers
805 Influence of Discharge Methods on Indoor Diffusion by Gaseous Extinction Equipment

KASHIGUCHI Tomoaki, ISHIKAWA Yoshiaki, KAWABATA Nobuyoshi, ISHIKAWA Takuji, NAITO Yusuke

The Proceedings of Conference of Hokuriku-Shinetsu Branch　2000　(0)　301-302　2000
Publisher: The Japan Society of Mechanical Engineers
806 Interaction of Exhaust Smoke between Sequential Tunnels

Shiojima Ken, Shimizu Hirohito, Sano Akinori, Kawabata Nobuyoshi, Ishikawa Takuji

The Proceedings of Conference of Hokuriku-Shinetsu Branch　2000　(0)　303-304　2000
Publisher: The Japan Society of Mechanical Engineers
609 Diffusion of the Gas discharged by Gaseous Extinction Equipment : Numerical Simulation and Real Experiment

ISHIKAWA Yoshiaki, KAWABATA Nobuyoshi, ISHIKAWA Takuji, NAITO Yusuke, MATSUMOTO Yoichiro, SAITO Naoshi, TSURUDA

The Proceedings of Conference of Hokuriku-Shinetsu Branch　2000　(0)　225-226　2000
Publisher: The Japan Society of Mechanical Engineers
610 Effect of Inclination on the Velocity of Thermal Fume in Emergency Tunnel Fires

ISHIKAWA Masao, HAYASHI Takumi, KAWABATA Nobuyoshi, ISHIKAWA Takuji, WANG Qian

The Proceedings of Conference of Hokuriku-Shinetsu Branch　2000　(0)　227-228　2000
Publisher: The Japan Society of Mechanical Engineers
608 Modeling of Gaseous Extinction Equipment by using Bond Graph

AKINO Takashi, KAWABATA Nobuyoshi, ISHIKAWA Takuji, NAITO Yusuke, TANAKA Kazuhiro

The Proceedings of Conference of Hokuriku-Shinetsu Branch　2000　(0)　223-224　2000
Publisher: The Japan Society of Mechanical Engineers

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Books and Other Publications 7

Integrated Nano-Biomechanics

T. Yamaguchi, T. Ishikawa, Y. Imai

Elsevier　2018/06
はじめての生体工学

山口昌樹, 石川拓司, 大橋俊朗, 中島求

講談社　2016/09/06
メカノバイオロジー

編曽我部正博

化学同人　2015/04/01
Visualization and a simulation of complex flows in biomedical engineering

Eds. R. Lima, Y. Imai, T. Ishikawa and, M S. N. Oliveira

Springer　2013/04
生物流体力学

編谷下一夫, 山口隆美

朝倉書店　2012/03
Handbook of Physics in Medicine and Biology

Eds. Robert, Splinter

CRC Press　2010/03
高度物理刺激と生体応答

編著, 佐藤岳彦, 大橋俊朗, 川野聡恭, 白樫了

養賢堂　2017/08/26

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Presentations 49

Ciliary fluid dynamics of swimming, feeding, pumping, and sensing Invited

Takuji Ishikawa

77th Annual Division of Fluid Dynamics Meeting (APS-DFD)　2024/11
Ciliary fluid dynamics of swimming, feeding, and pumping Invited

Takuji Ishikawa

Microscale Ocean Biophysics 7.0　2024/05/27
SOFT CAPSULE ROBOT CONTROLLED BY FLUID OSCILLATIONS Invited

Takuji Ishikawa, Takeru Morita, Toshihiro Omori

Dynamics of Capsules, Vesicles and Cells in Flow　2023/06/10
Bubble Induced Transport Phenomena in Yeast Fermentation Invited

Takuji Ishikawa, Atul Srivastava, Kenji Kikuchi

the 9th World Congress of Biomechanics　2022/07/11
Biomechanics can provide a new perspective on microbiology International-presentation Invited

Takuji Ishikawa

8th World Congress of Biomechanics　2018/07/10
微生物の非定常な遊泳が生み出す走流性と軸集中 Invited

石川拓司

日本機械学会第35回バイオエンジニアリング講演会　2023/06/04
Hydrodynamics of Ciliary Swimming Invited

Takuji Ishikawa

Applied Math Seminar Series, University of Hawaii at Manoa　2023/03/08
Biomechanical model of microbial taxis and behaviors Invited

Takuji Ishikawa

Engineering Mechanics of Cell and Tissue Morphogenesis　2022/06/04
微生物の走性・行動の力学モデル Invited

石川拓司

「ジオラマ環境で覚醒する原生知能を定式化する細胞行動力学」シンポジウム　2022/03/10
Functions and Efficiency of Ciliary Swimming Invited

Takuji Ishikawa

2021/09/07
Hydrodynamics of ciliary swimming Invited

Takuji Ishikawa

Biofluid Symposium in Biofluids 2021　2021/07/23
小さな生物周りの流れの基本法則 Invited

石川拓司

RIMS Tutorial Seminar 生物の創るパターンとダイナミクス：基礎からの展開　2021/06/15
Functions and Efficiency of Ciliary Swimming Invited

Takuji Ishikawa

21st RIES-Hokudai International Symposium　2020/12/10
遊泳微生物の動的機能形態学 Invited

石川拓司

2020/12/05
Biomechanics as a tool for understanding microorganisms Invited

Takuji Ishikawa

Mini-symposium on Fluid-Structure Interactions: From Engineering to Biomimetic Systems, Okinawa (2020.1.15) Biomechanics can provide a new perspective on microbiology　2020/01/15
Biomechanics can provide a new perspective on microbiology Invited

Takuji Ishikawa

Workshop on Physics of Soft, Active and Living Matter　2020/01/07
Biomechanics can provide a new perspective on microbiology Invited

Takuji Ishikawa

Fluid Dynamics Seminar, Imperial College London　2019/06/07
Biomechanics can provide a new perspective on microbiology Invited

Takuji Ishikawa

Mathematical Physics Seminar, University of York　2019/06/04
Biomechanics can provide a new perspective on microbiology Invited

Takuji Ishikawa

Mathematical Biology and Ecology Seminar, University of Oxford　2019/05/03
Understanding motions of cells by mechanics Invited

石川拓司

流れと澱みを語る会2018　2018/06/10
Near-field fluid mechanics alter behaviors of swimming microorganisms International-presentation Invited

アクティブマター研究会　2018/01/20
狭い流路内の繊毛虫の遊泳挙動 Invited

日本機械学会第30回バイオエンジニアリング講演会シンポジウム　2017/12/15
バイオエンジニアリング研究の過去と未来 Invited

日本機械学会第30回バイオエンジニアリング講演会イブニングセッション　2017/12/14
Deformation and the resultant motion of a red blood cell International-presentation Invited

Blood Flow: Current State and Future Prospects　2017/10/10
Hydrodynamic Bound States of a Squirmer International-presentation Invited

5th Switzerland-Japan Workshop on Biomechanics (SJB2017)　2017/09/15
行き止まりを避ける微生物の泳ぎ Invited

違った視点で捉える流れ　2017/09/08
Deformation and Motility of Cells Invited

第一回アクティブ・ソフトマター研究会　2016/11/14
Modeling and Understanding Biomedical Flows International-presentation Invited

2nd Global Conference on Biomedical Engineering　2016/08/17
Biological flow studies from cellular to macro scale International-presentation Invited

International Conference on Future Healthcare and Economic Development in Southeast Asia　2016/08/16
Deformation and Motility of Cells International-presentation Invited

Summer School 2016 Active Complex Matter　2016/07/13
遊泳大腸菌の流体力学 Invited

べん毛研究交流会　2016/03/06
微小遊泳体の流体力学的な制御機構 Invited

第5回ソフトマター研究会　2015/12/18
シミュレーションで拓く医工学 Invited

第18回血管病態研究会　2015/11/14
Hydrodynamic Regulation and Control of a Micro-swimmer International-presentation Invited

3rd Int. Workshops Adv. Comp. Mech.　2015/10/12
Separation of motile bacteria using drift force near a wall International-presentation Invited

Computational Fluid Dynamics in Medicine and Biology II　2015/09/02
Transport Phenomena in Suspensions of Swimming Microorganisms International-presentation Invited

The Korean Society of Mechanical Engineering　2015/05/21
微生物溶液のダイナミクス Invited

京都大学基礎物理学研究所セミナー　2009/10
Mixing of red blood cells in high hematocrit blood flow in micro-channels International-presentation Invited

3rd Switzerland-Japan Workshop on Biomechanics 2009　2009/09
微生物溶液のバイオメカニクス Invited

特定領域研究「ソフトマター物理」第4回領域研究会　2009/07
Suspension biomechanics of swimming microbes International-presentation Invited

Workshop on Active Matter – Physics of Biokinetics　2009/07
Computational biomechanics of malaria and arterial diseases International-presentation Invited

37th Int. Cong. Physiol. Sci.　2009/07
Computational biomechanics for investigating various diseases over micro to macro scales International-presentation Invited

Int. Conf. Comp. Exp. Eng. Sci.　2009/04
Motion of individual cells in high hematocrit blood flow in micro-channels International-presentation Invited

Int. Conf. Comp. Exp. Eng. Sci.　2009/04
Fluid dynamics of a suspension of locomotive cells International-presentation Invited

Int. Conf. Nonlinear Sci.　2009/02
Biomechanics of a Suspension of Micro-Organisms International-presentation Invited

13th Int. Conf. Biomed. Eng. (ICBME2008)　2008/12
Hydrodynamics of swimming micro-organisms International-presentation Invited

8th. World Congress on Computational Mechanics, and the 5th. European Congress on Computational Methods in Applied Sciences and Engineering　2008/07
Collective motions of locomotive cells in a suspension International-presentation Invited

Tohoku-NUS Student Joint Symposium　2008/05
微生物の濃厚溶液の数値シミュレーション Invited

第13回計算数理工学フォーラム　2007/09
微生物溶液の数値シミュレーション Invited

第18回エアロ・アクアバイオメカニズム研究会　2006/03

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Industrial Property Rights 4

血液中の粒子分離装置

石川拓司, 田中達也, 沼山恵子, 上野裕則, 今井陽介, 山口隆美

Property Type: Patent
Vibrating needle device and needle insertion method

Kenji Kikuchi, Kojiro Sugiyama, Takuji Ishikawa, Kei Takase

Property Type: Patent
呼気補助装置および人工呼吸用装置

高橋和博, 山内正憲, 外山裕章, 石川拓司, 菊地謙次, 荒田悠太郎, 江島豊

Property Type: Patent
振動針装置及び針の挿入方法

菊地謙次, 杉山航二郎, 石川拓司, 高瀬圭

Property Type: Patent

Research Projects 29

Development of non-invasive imaging methods of Biological flow and concentration field for in vivo physiological immune system interference

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2022/04/01 - 2026/03/31
環境連成力学を基盤とした微生物行動シミュレータの開発

石川拓司, 上野裕則, 西上幸範

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 学術変革領域研究(A)

Institution: 東北大学

2021/09/10 - 2026/03/31

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本年度は研究の立ち上げを行い、大型計算機を入札により導入した。主要な研究実績は以下の通りである。１．クラミドモナスが流れに逆らって泳ぐ性質（走流性）を示すことを発見した。実験と理論、数値シミュレーションを融合し、そのメカニズムが遊泳の非定常性からくることを明らかにした（Omori, et al., J. Fluid Mech. 2021）。２．さまざまな遊泳モードを持つ微生物の2体干渉の解析を行い、干渉運動の相図を作成した。これにより、微生物干渉の体系的な理解が進んだ（Darveniza, et al., Phys. Rev. Fluids,2022）。３．数値解析手法の高度化にも取り組み、汎用性の高い境界要素法と近接場が得意な潤滑理論を融合させたLT-BEMを開発した。この手法を用いることで、微生物運動の解析精度が大幅に改善することを示した（Ishikawa, J. Comp. Phys., 2022）。４．開発した微生物行動シミュレータをバイオフィルムの形成過程へと展開した。複雑流路内に形成されるストリーマーの形成過程を、細胞スケールからメゾスケールで計算した。そして、マクロなレオロジー特性とストリーマー形状の関係を解明した（Kitamura, et al., J. R. Soc. Interface, 2021）。５．開発した微生物行動シミュレータを酵母の発酵過程へと展開し、培養時の輸送現象を定量的に調べた。培養容器内にプラスチックごみを模擬した物体を混入させると、ブラジルナッツ効果が現れることを発見した。この成果はSoft Matter誌の背表紙を飾り、プレスリリースされた（Srivastava, et al., Soft Matter, 2021）。
Ethological dynamics to formulate proto-intelligence exerted in diorama environments.

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Transformative Research Areas (A)

Institution: Hokkaido University

2021/09/10 - 2026/03/31
Study on active transport phenomena for predicting and controlling biological active matter

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (S)

Institution: Tohoku University

2021/07/05 - 2026/03/31
薬剤輸送を目指した柔らかいマイクロスイマーの開発

石川拓司, 菊地謙次, ニックスステファニー, 大森俊宏

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 国際共同研究加速基金(国際共同研究強化(B))

Institution: 東北大学

2021/10/07 - 2025/03/31
バイオメカニクスで紐解くバイオフィルム形成の仕組み

石川拓司, YANG JINYOU

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 特別研究員奨励費

Institution: 東北大学

2021/11/18 - 2024/03/31

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本年度は、研究環境の整備と、研究の立ち上げを行った。本来、楊氏は2020年8月に来日予定であったが、コロナ禍の影響で2021年12月まで研究を始められなかった。この間にバイオフィルム研究は日進月歩で深化しているため、最新の研究動向を調査し、研究課題とスケジュールを状況に合わせて軌道修正した。実験準備として、腸内細菌を観察するためのゼブラフィッシュの実験系を構築した。飼育と産卵、稚魚の観察、麻酔、大腸菌の挿入などの一連のスキルを習得した。また、蛍光顕微鏡によるライブイメージング技術を習得した。微細流体流路を製作するための基礎技術も習得した。これらの技術を基盤とし、ゼブラフィッシュ腸内の大腸菌のライブイメージングに成功した。さらに、シミュレーションのためのコード開発にも取り組んだ。物理環境下のバクテリア挙動を解析するため、境界要素法を基盤とする解析コードを構築している。東北大学流体科学研究所のスパコンを使用するための事務手続きや、技術習得も行った。計算コードのバグ取りは終了し、試行計算で良好な結果が出ている。
バイオメカニクスで紐解くバイオフィルム形成の仕組み

石川拓司, YANG JINYOU

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 特別研究員奨励費

Institution: 東北大学

2021/07/28 - 2023/03/31
バイオメカニクスで紐解くバイオフィルム形成の仕組み

石川拓司, YANG JINYOU

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 特別研究員奨励費

Institution: 東北大学

2021/04/28 - 2023/03/31
ノイズで推進する柔らかいマイクロスイマーの開発

石川拓司

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 新学術領域研究(研究領域提案型)

Institution: 東北大学

2021/04/01 - 2023/03/31
バイオメカニクスで紐解くバイオフィルム形成の仕組み

石川拓司, YANG JINYOU

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 特別研究員奨励費

Institution: 東北大学

2020/11/13 - 2023/03/31
Development of a simulator to evaluate the efficacy of an antibacterial agent to resident and resistant bacteria

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Challenging Research (Exploratory)

Institution: Tohoku University

2020/07/30 - 2023/03/31
Physiological function generated by biological flow

Kikuchi Kenji

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (B)

Institution: Tohoku University

2019/04/01 - 2022/03/31

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In this research, we thoroughly pursued the "Physiological function generated by biological flow" and succeeded in taking it to heights unparalleled anywhere in the world, utilizing experimental and theoretical analysis and numerical simulation methods. Subsequently, we have elucidated biological phenomena from microorganisms to drug absorption in the skin on scales from microscopic to centimeters, and developed engineering and medical engineering technologies related to biological flow.The results have been published as 9 peer review journal papers.
Modeling a gut flora of a zebrafish by combining experiments, theories and numerical simulations

Ishikawa Takuji

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Challenging Research (Exploratory)

Institution: Tohoku University

2018/06/29 - 2021/03/31

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In this project, we investigated microbial flora in the intestine of a zebrafish larva by combining theories and experiments based on transport phenomena. Three conservation laws (momentum, concentration and cells) are solved simultaneously, and the distribution and growth of bacteria are described. We also conducted experiments using a zebrafish larva. We established the experimental setup, and measured intestinal flow with high temporal and spacial resolutions.
Upgrading Microbial Biomechanics

Ishikawa Takuji

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (A)

Institution: Tohoku University

2017/04/01 - 2021/03/31

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By using an original method that carefully builds up physical laws from the nanoscale to the macroscale, we have clarified the behavior and biological functions of sperm, microalgae, ciliates, E. coli, yeast, and other organisms under mechanical environments. We succeeded in analyzing through the scale hierarchy from the movement of ciliary axonemes driven by molecular motors, synchronization of flagellar movement, swimming and biological responses of ciliates with many flagella, two-body interactions and cooperative swimming, rheology and diffusion properties as a continuum, cell growth and accumulation, and so on. These results were published in a total of 48 peer-reviewed journal articles, including two in PNAS, one in Science Adv, and six in J Fluid Mech. In addition, 8 press releases were issued to widely publicize the research results.
Development of a taxis model of cells: application for medicine and evolutionary biology

Ishikawa Takuji

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Fund for the Promotion of Joint International Research (Fostering Joint International Research)

Institution: Tohoku University

2018 - 2021

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The research methodology of the parent project includes the step of "innovating theoretical and analytical methods" for microbial biomechanics. In this study, therefore, the mathematical model of phototaxis of microalgae (Gonium) was developed by combining the experimental and mathematical results of the Goldstein Laboratory at the University of Cambridge with the applicant's simulation technology. We have also conducted swimming and feeding analyses of groups of collar flagellates, the origin of multicellular animals, and has expanded microbial biomechanics into evolutionary biology. Besides, we collaborated with Professors Pedley and Lauga of the same department to analyze the stability of microbial swimming and mathematical modeling of microbial suspensions. These results were published in a total of six refereed journal papers, including two in J Fluid Mech, one in Phys Rev E, and one in J Comp Phys.
Advances in cell suspension mechanics based on the hierarchy structure

Ishikawa Takuji

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (A)

Institution: Tohoku University

2014/04/01 - 2017/03/31

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In this project, we have succeeded to construct a world leading ‘cell suspension mechanics based on the hierarchy structure’ by combining experiment, theory and numerical simulation. We have clarified many phenomena from nano to macro scale using various cells such as algae, bacteria and blood. Then, the obtained knowledge was utilized to develop devices for engineering and biomedical use. The results have been published as 30 peer review journal papers.
Integrated nano-biomechanics

YAMAGUCHI Takami, ISHIKAWA Takuji, UENO Hironori, MIZUNO Fumio, OMORI Toshihiro, MATSUKI Noriaki, TANAKA Tetsu, SHIMOGONYA Yuji, NIX Stephanie, NUMAYAMA Keiko, IMAI Yohsuke

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Specially Promoted Research

Institution: Tohoku University

2013 - 2017

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We have established integrated nano-biomechanics by modeling multi-scale physical and biomedical phenomena from the molecular level. By using the established model, we succeeded to numerically simulate various diseases, such as an infectious disease, and developed novel methodologies for medical diagnosis and treatments based on quantitative predictions. Besides, we developed biochips to separate or detect cancer cells and bacteria. These findings have been published as 50 peer reviewed journal papers.
気道上皮細胞が作る流れの共焦点マイクロＰＩＶ計測

石川拓司, SAADATMAND Maryam

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 特別研究員奨励費

Institution: 東北大学

2013/04/01 - 2015/03/31

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本年度は、マウスから摘出した気道を用い、繊毛が作り出す流れを共焦点マイクロPIVシステムを用いて可視化計測した。特に、粘液粘度の影響に着目し、粘度増加による繊毛打の変化や、繊毛流れの変化を計測した。その結果、高い粘度環境下においても繊毛打は消滅しないが、繊毛打周波数は低下し、繊毛流れが遅くなることを明らかにした。また、気管と気管支における繊毛流れの違いを調べたところ、両者には大きな違いがないことが明らかになった。これらの実験により、病変等で粘液粘度が高くなった条件下における、気道内における繊毛流れの機能、および粒子の輸送効率を議論することが可能となった。こうした成果は、気道のクリアランス機能の病理を理解する上で重要であり、PCDなどの疾患のメカニズムの理解に役立つと考えられる。さらに、修得したマイクロ流れの計測技術を生かし、微小流体流路内の血液流れなど、他の生物流れの計測も並行して行った。特筆すべきは、PDMSマイクロ流路の壁内にバイパス流路を埋め込むことで、血球成分が壁面から離れ、血漿層の厚みを増幅できることを世界で初めて示した。この壁面形状を、血液に接触する医療機器の表面に応用することで、血液の凝固や溶血などを予防できると期待される。この成果は、国際会議にて口頭発表している。こうした派生的な研究成果も、本課題の研究手法の開発に資するのみならず、特別研究員の将来の活躍の場を広げるものであり、重要である。
Analyses of small molecules behaviors in the body which is emerged by the cooperation of multi-organs.

SUZUKI Hiroshi, HONMA Masashi, TAKADA Tappei

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)

Institution: The University of Tokyo

2010/04/01 - 2015/03/31

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Homeostasis for blood concentrations of various small molecules is one of the most important mechanisms to maintain life. In the present study, we focused on this system which is emerged by the cooperation of multi-organs, aiming to achieve the integrated comprehension of the systems behaviors. In the first half of the study period, we have built novel mathematical models to describe the behavior of small molecules in the body, using drug molecules as models. In the second half of the study, we extended the target ranges to various endogenous small molecules, including highly lipophilic compounds such as cholesterol and fat-soluble vitamins, inorganic salts such as phosphate and calcium, and urate. We have elucidated molecular mechanisms for regulating the behavior of these compounds in the body, and have integrated the information to the multi-organ models.
細胞サスペンジョン力学による医工学研究の新展開

石川拓司

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 基盤研究(B)

Institution: 東北大学

2010 - 2014

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本研究課題では,実験・理論解析・数値シミュレーションを駆使することで,細胞間の多体干渉現象および複雑流路内での振舞いを新たに解明し,まず始めに細胞サスペンジョン力学を確立することを目的とする.そして細胞サスペンジョン力学を応用し,従来の手法では議論が困難な生命システムを定量的に解明する.これにより,従来は経験的・定性的な議論に留まっていた医工学の分野に,ブレークスルーを生み出すことを目的とする.本年度は主に以下の2つの研究課題を遂行した. 1.細胞間の多体干渉モデルの構築微生物の2体干渉現象を多体間に拡張し,まず始めに遊泳微生物がどのようなメゾスケール流動構造を示すか実験的に調べた.微生物には大腸菌を用い,共焦点マイクロPIVシステムを用いて高濃度溶液内の大腸菌の運動,および周囲流体の流動を計測した.次に,高濃度バクテリア溶液に対する数理モデルを構築した.本研究では球形以外の形状を取り扱えるよう従来の計算コードを改良し,高濃度バクテリア溶液の数理モデルを提案した.赤血球に対しては,我々の開発してきた境界要素法を赤血球に拡張し,高濃度赤血球サスペンジョンに対する高精度な数理モデルを構築した. 2.複雑流路内の細胞サスペンジョン流動の解明血液にごく少量のがん細胞を混入し,狭さく部や分岐・合流部における挙動を調べた.そしてがん細胞の軸集中や壁面への集中など,力学的なに引き起こされる特異な流動現象を解明した.次に,開発した多体干渉を表現できる細胞サスペンジョンモデルを用い,実験に対応する複雑流路内の流れのシミュレーションを行った.そしてシミュレーション結果と実験結果を比較検討することにより,信頼性の高い細胞サスペンジョンシミュレータを開発した.
Nano-scale analysis and computational fluid mechanics of the flow on the surface of tracheal lumen

UENO Hironori, ISHIKAWA Takuji, ISHIKAWA Takashi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Young Scientists (B)

Institution: Tohoku University

2009 - 2011

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Mucociliary clearance on the surface of the tracheal lumen is an important component of lung defense against viruses and bacteria. We analyzed the detail of ciliary movement with high spatial precision by labeling the ciliary tip using quantum dots, and axonemal structure by cryo-electron tomography. We revealed the overall directional flow from the lungs to the oropharynx on tracheal lumen by effective ciliary motion with the asymmetric axonemal structure. Moreover, we discovered that collective swimming of microorganisms is the most energy-efficient way of moving. And also, we developed new program code and GPGPU computational system to analyze the fluid flow mechanism on the surface of tracheal lumen.
Mechanism of the inhibition of cancer cell growth using low voltage electric pulses

MATSUKI Noriaki

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (C)

2009 - 2011

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We previously reported that cancer cell apoptosis was induced through electroporation(membrane pore formation) with the application of low voltage electric pulses(LVEPs). In this study, we reported about the apoptosis mechanism of cancer cells that LVEPs impose cell stress and induce apoptosis through caspases activation of both cell death receptor and mitochondrial pathways following intrcellular Ca++elevation. A series of our studies suggest that LVEPs which might be mild damage to the patients could take place of high voltage electrochemtherapy which is studied as a new anti-cancer therapy.
Computational nano-biomechanics for the diagnosis, treatment, and prevention of diseases of blood, circulatory, and digestive organs

YAMAGUCHI Takami, ISHIKAWA Takuji, IMAI Yohsuke, MORI Daisuke, MATSUKI Noriaki, MIZUNO Fumio

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (S)

Institution: Tohoku University

2007 - 2010

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We have developed computational nano-biomechanics for the diagnosis, treatment, and prevention of diseases of blood, circulatory, and digestive organs. We proposed a novel hemodynamic index to predict the initiation of cerebral aneurysms. A numerical model of microvascular blood flow was developed for simulating microvascular occlusion in malaria infection, and thrombogenesis. A model of swimming microorganisms was also developed for analyzing intestinal flora.
Reconstruction of a bio-fluid dynamics model from the cellular level

ISHIKAWA Takuji

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Young Scientists (A)

Institution: Tohoku University

2007 - 2009

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We had developed a numerical model of microorganisms, red blood cells and cancer cells by 2008. We also tried to model biological reaction of cells. In 2009, we utilized these models and computed many body interactions of cells in a suspension. Then we compiled a database for the stress field, diffusion tensor under various conditions. We also developed a mathematical model of these tensor values under simplified conditions. Besides, we develop a numerical model to solve population of bacteria in the human intestine by combining the cellular level models and the macroscopic models. We established a base for the multi-scale and multi-physics simulation for the microbial flora in the intestine.
病変を伴う小動脈内の血流と血球同士の干渉による特異流動

石川拓司

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 若手研究(B)

2005 - 2006

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血球の干渉と血流の数値シミュレーション実際の血液のヘマトクリット値は40-50%と非常に高く,赤血球同士が結合してルーロー(連銭)を形成するなど複雑な挙動を示すため,赤血球同士の干渉を表現することは実際の血流を取り扱う上で非常に重要なステップである. 申請者はこれまでに,Bradyらが剛体球の濃厚サスペンションを対象に開発したStokesian Dynamics Simulationの手法を微生物溶液に適用し,ミクロスケールの粒子間の流体力学的干渉を厳密に表現することに成功してきた.本年度はその手法を赤血球に適用し,赤血球の濃厚溶液である血液の数理モデル化を行った.特に赤血球の近距離干渉に焦点を当て,高分子の架橋構造による干渉力をばね力でモデル化することに成功した.狭さく部を通る血流の数値シミュレーションも行い,解析結果を実験結果との比較した. 赤血球を用いた血球の干渉実験および血流の可視化実験シミュレーションの妥当性を検討するには,対応する実験データが不可欠である.そこで本研究では,研究室に既存のconforcal-micro PIVシステムを用い,染色した赤血球の干渉実験および血流の可視化実験を行った.微小血管の狭さく部を模擬した流路は,PDMS micro channelを用いて作成した.実験結果を数値シミュレーション結果と比較検討し,解析手法の妥当性を確認した.
Mechanism of the formation, destruction, and movement of thrombi responsible for ischemia of vital organs

YAMAGUCHI Takami, WADA Shigeo, TSUBOTA Ken-ichi, ISHIKAWA Takuji, IMAI Yohsuke

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (A)

Institution: Tohoku University

2004 - 2006

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We investigated multi-scale behaviors of the formation, destruction, and movement of thrombi under blood flow that are responsible for ischemia of vital organs by using computer simulation and in vitro experiments based on biomechanics. We carried out computer simulations based on a Stokesian Dynamics method and a particle method to characterize the relationships between physiological and fluid mechanical factors in platelet aggregation under blood flow. We determined the relationships between deformation of red blood cells and apparent blood flow resistance. The result indicated that interactions among blood cells play a pivotal role in blood flow properties. It was also shown that biological/mechanical interactions among different types of blood cells determine thrombogenesis process. We established an in vitro quantitative measurement of blood flow through micro channel with micro PIV system, and obtained a spatiotemporal velocity fluctuation in blood flow that depends on hemaetocrit values. This indicated that mechanical interaction among blood cells governs blood flow properties. We proposed a large-scale computer simulation model of flow of red blood cells with the Earth Simulator, and established mathematical formulae of blood flow that can explain hierarchical mechanical behaviors of blood flows from the scale of blood cells (jam) to large vessel (cm). We also developed an integrated computer model of the left ventricle and the aorta, and demonstrated that the model is practically useful in detailed evaluation of the vortex and stagnation, which greatly affects thrombogenesis, in heart and large arteries.
Study on Mechanisms of the Development of Cardiovascular and Cerebrovascular Diseases

YAMAGUCHI Takami, ISHIKAWA Takuji, TSUBOTA Ken-ichi, IMAI Yohsuke, WADA Shigeo

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research on Priority Areas

Institution: Tohoku University

2003 - 2006

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Human cardiovascular system is always under the integrated nervous and Humoral control of the whole body, i.e., in homeostasis. Multiple feedback mechanisms with mutual interactions among systems, organs, and even tissues provide integrated control of the entire body. These control mechanisms have different spatial coverage, from the micro- to macroscale, and different time constants, from nanoseconds to decades. Based on this consideration, we investigated the cardiovascular system over micro to macro levels by using conjugated computational mechanics analyzing fluid and solid interactions in the research project. We studied blood flow in the aorta with beating left ventricle as a power source, ATP transport in a cerebral artery with aneurysm, the progress of cerebral aneurysm due to adaptation of arterial wall, the blood flow considering more than 16 thousands of red blood cells' motion, and platelets aggregation in blood flow using a particle method developed for the purpose. The aortic blood flow showed independence from the intraventricular vortices formation downstream from the aortic arch, where the three dimensional configuration of the aorta determined the global flow structure. Transport and distribution of ATP molecule was found to be strongly dependent on the relative position of aneurysms to the mother arteries. The particle method developed in the present study showed its potential to represent the microscale aggregation process of the platelet in the blood flow. In considering clinical applications, however, one needs to include more about biological complexities in the analysis of blood flow, especially with respect to disease processes. A disease is not just a failure of machine. It is an outcome of complex interactions among multi-layered systems and subsystems. We expect that biological phenomena, including disease processes, will be clarified in the future by integrating new understandings of macroscale and microscale hemodynamics.
動脈硬化症を伴う細動脈を通る血流と赤血球の特異流動

石川拓司

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 若手研究(B)

Institution: 福井大学

2002 - 2003

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細動脈内の動脈硬化症の進展においては,流体力学的要因が重要な役割を果たすことが報告されているため,細動脈狭さく部における血流を解明することは重要である.従来の動脈内の血流を対象とした研究は大半が大動脈を対象としており,小動脈や細動脈を対象とした研究は数少ない.この原因は,血液中に含まれる赤血球の直径は8μm程度であり,直径が0.1mm程度の細動脈においては血液を均質と仮定できず,構成方程式の適用に限界があるためである. そこで本年度は,これまでに申請者が開発してきた赤血球の分布と変形を考慮できる離散的な数値解析手法(DEM)を用い,細動脈内の狭さく部を通る血流を調べるための数値シミュレーションコードを開発した.そして数値シミュレーションをさまざまなケースで実施し,狭さく部周辺での流れの様子や壁面せん断応力などの諸量を調べた.その結果,冠状動脈や脳内の細動脈における動脈硬化症進展のメカニズム解明に有用な知見を得ることができた.この研究成果は,日本機械学会2002年度年次大会講演論文集に発表されている.次年度は,ルーロー(連銭)構造の形成過程を表現できるよう,数値解析コードを改良する予定である. また,本年度は数値解析と平行して模擬赤血球の定ずり速度下の挙動を調べるための実験装置を製作した.多くの種類の模擬赤血球を試作し,本実験に適したマイクロカプセルの作成に成功した.実験装置はほぼ完成しており,次年度に多くの実験を実施し,数値シミュレーションとの対応付けを行う予定である.
血液のミクロスケール流れを表現できる数値シミュレーション手法の開発

石川拓司

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 奨励研究(A)

Institution: 福井大学

2000 - 2001

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従来の動脈内の血流を対象とした研究は大半が大動脈を対象としており,細動脈や微細動脈を対象とした研究は数少ない.この原因は,血液中に含まれる赤血球の直径は8μm程度であり,直径が0.1mm以下の細動脈においては血液を均質と仮定できず,赤血球の取り扱いが難しいためと考えられる.均質な非ニュートン流体の流れを解く場合には,ずり速度と応力の関係を表す構成方程式を用いてレオロジー的挙動を記述する.しかし細動脈内の血流のように均質を仮定できない場合には,構成方程式の適用には限界があると考えられる.そこで本研究では,球とばね,ダンパを用いたモデルを流体内に多数混入し,構成方程式を用いずに血液の粘弾性的な挙動を表現することを目的として研究を行っている. 平成13年度は血液のポアズイユ流れの数値シミュレーションを行い,日本機械学会2001年度年次大会において「変形する赤血球モデルによる血液のポアズイユ流れのシミュレーション」という題目で講演を行った.また,「Proposal of a Deformable Erythrocyte Model and Numerical Analysis of a Shear Flow of Blood」という題目で,JSME International J.に1編の論文が掲載され,日本機械学会誌にも1編の論文が掲載されている.このように,研究成果は順調に上がっている. また,今年に入り細動脈内狭さく部を通る血液の数値シミュレーションを開始しており,日本機械学会2002年度年次大会において「離散赤血球法による細動脈狭さく部を通る血流のシミュレーション」という題目で講演を行う予定である.

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Social Activities 30

医療工学技術者創成のための再教育システム

2006/04/01 - 2018/03/31

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講師「生体力学」
EMBEE 講師

EMBEE

2019/04/01 -
Microorganisms Can Escape from a Dead End by Swimming

2018/03/23 -
微生物は危険な場所を巧みに回避することができる

2018/03/02 -
東北大、デッドエンドを回避する微生物の仕組みを発見

2018/03/01 -
細菌のべん毛は、スピンだけでなく旋回運動もしていた―東北大・下權谷祐氏ら

2016/01/06 -
意外と知られていなかった生物の不思議：細菌のべん毛、付け根も旋回している意外な事実を発見

2015/12/28 -
東北大と阪大、細菌のべん毛のコマのような回転挙動のメカニズムを解明

2015/12/28 -
Fast, Fluid Cells Spread Cancer

2015/12/16 -
生き物の明日を予測する～生物シミュレーションの最前線～

2014/12/11 -

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仙台市立仙台青陵中等教育学校・講演会
Featured in Kaleidoscope: Dispersion of model microorganisms swimming in a nonuniform suspension

2014/10/10 -
市民講座「未来をツクル ―東北大学機械系若手研究者の挑戦―」

2013/08/25 -

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市民講座「未来をツクル ―東北大学機械系若手研究者の挑戦―」
市民講座「世界をリードする東北大学機械系の若手研究者が目指す未来社会」

2012/12/27 -

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市民講座「世界をリードする東北大学機械系の若手研究者が目指す未来社会」
乳がん細胞低コスト検出

2012/03/07 -
市民講座「世界をリードする東北大学機械系の若手研究者が目指す未来社会」

2012/03/01 -

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市民講座「世界をリードする東北大学機械系の若手研究者が目指す未来社会」
Bacteria, live in 3D

2011/07 -
Tiny travelers take on a viscous world

2009/07 -
出会い求め？ダンスを踊る藻類「ボルボックス」

2009/05 -
Not Bad For Pond Scum

2009/04 -
東北大学、藻類のボルボックスがワルツやメヌエットなどのダンスを踊る姿を発見

2009/04 -
团藻运动研究

2009/04 -
Descubren algas que 'bailan' para mantenerse unidas

2009/04 -
Study: Algae can form stable groupings

2009/04 -
Scientists discover 'dancing' algae

2009/04 -
`Dancing' algae can `waltz' and `minuet'

2009/04 -
Cientistas britânicos descobrem 'algas dançarinas'

2009/04 -
Pond Scum to Pond Scum: “Shall we dance?”

2009/04 -
藻類、優雅に“ワルツ” 東北大グループ発見

2009/04 -
Shall we dance?

2009/04 -
Research Highlights : Dynamics of a dance

2009/04 -

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Media Coverage 16

6億年も生き抜いてきた動物？最古の多細胞動物＜海綿＞は最適化されたポンプ機能を持つことが判明

YahooJapanニュース　YahooJapanニュース

2025/03

Type: Internet
心臓は左…体の「左右」はどう決まる? カギは2種類の「毛」の共演

朝日新聞デジタル

2023/01

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体の左右非対称を決めるのは、化学物質ではなく「力」と判明

Newsweek日本版

2023/01

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体の左右非対称を決めるのは、化学物質ではなく「力」と判明

YahooJapanニュース

2023/01

Type: Internet
Visualization of the "Brazil nut effect," an interesting phenomenon of microbial origin

Science Japan

2022/02

Type: Internet
流れに逆らって泳ぐ微生物

読売新聞

2022/01

Type: Newspaper, magazine
競争ではなく協力...「精子は助け合って泳ぐ」東北大が発表不妊治療へ期待

テレ東ニュース

2020/11

Type: TV or radio program
単細胞から多細胞生物へ、進化の謎を解き明かす鍵を解明東北大

BIGLOBEニュース

2020/11

Type: Internet
マスクや衣服の擦れによる皮膚の脆弱化メカニズムを解明

日本学術振興会HP

2020/09

Type: Promotional material
線虫「静電気ジャンプ」

読売新聞　読売新聞

2023/07

Type: Newspaper, magazine
哺乳類の体のつくりが左右非対称その仕組みは？

NHK NEWS WEB

2023/01

Type: TV or radio program
臓器づくりの左右非対称性発生初期機械的な力で決定

科学新聞

2023/01

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大きな粒子が浮上小さな粒子が沈降微生物由来の興味深い現象発見

科学新聞

2021/12

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ウイルス感染リスクが高まる長時間のマスク着用 - 摩擦刺激で皮膚が脆弱化

マイナビニュース

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