顔写真

キクチ ケンジ
菊地 謙次
Kenji Kikuchi
所属
大学院工学研究科 ファインメカニクス専攻 バイオメカニクス講座(生体流体力学分野)
職名
准教授
学位
  • 博士(工学)(東洋大学)

  • 修士(工学)(東洋大学)

e-Rad 研究者番号
00553801

委員歴 21

  • 可視化情報学会 理事(第31期、第32期)

    2019年6月 ~ 継続中

  • 可視化情報学会 学会誌編集委員会 オンライン担当委員

    2012年1月 ~ 継続中

  • 可視化情報学会 学会誌編集委員会 オンライン担当委員

    2012年1月 ~ 継続中

  • 第35回日本機械学会バイオエンジニアリング部門講演会実行委員(幹事)

    2022年6月 ~ 2023年6月

  • 可視化情報学会主催 第50回可視化情報シンポジウム 実行委員

    2021年7月 ~ 2022年8月

  • 日本機械学会バイオエンジニアリング部門 広報委員

    2020年3月 ~ 2022年3月

  • 日本機械学会バイオエンジニアリング部門 部門代議員

    2018年3月 ~ 2020年2月

  • International Conference on Fluid Mechanics2018 Local committee

    2017年1月 ~ 2018年9月

  • 日本機械学会東北支部講演会 実行委員

    2017年8月 ~ 2018年3月

  • 日本機械学会流体工学部門 P-SCC13マイクロ熱流動に関する調査研究分科会 委員

    2015年10月 ~ 2017年9月

  • 可視化情報学会主催 第45回可視化情報シンポジウム 実行委員

    2016年8月 ~ 2017年7月

  • 日本機械学会 流体工学部門 P-SCD382 せん断流の多様な機能の探求と先端科学技術への応用に関する研究分科会 委員

    2013年10月 ~ 2016年9月

  • 可視化情報学会主催 第44回可視化情報シンポジウム 実行委員

    2015年8月 ~ 2016年7月

  • 可視化情報学会主催 第43回可視化情報シンポジウム 実行委員

    2014年8月 ~ 2015年7月

  • 可視化情報学会主催 第42回可視化情報シンポジウム 幹事

    2013年8月 ~ 2014年7月

  • VSJ The 16th International Symposium on Flow Visualization Local Organizing Committee

    2013年6月 ~ 2014年7月

  • 可視化情報学会主催 The 16th International Symposium on Flow Visualization Local Organizing Committee

    2013年6月 ~ 2014年7月

  • 日本機械学会主催 流体工学部門 P-SCD366 噴流,後流,およびはく離流れの基礎と先進的応用に関する研究分科会 委員

    2011年10月 ~ 2013年9月

  • 可視化情報学会主催 第41回可視化情報シンポジウム 幹事

    2012年8月 ~ 2013年7月

  • JSME International Conference on Jet, Wake and Separated Flow (ICJWSF2013) Local Organizing Committee

    2012年4月 ~ 2013年6月

  • 日本機械学会 流体工学部門主催 International Conference on Jet, Wake and Separated Flow (ICJWSF2013) Local Organizing Committee

    2012年4月 ~ 2013年6月

︎全件表示 ︎最初の5件までを表示

所属学協会 4

  • アメリカ物理学会

  • 可視化情報学会

  • 日本流体力学会

  • 日本機械学会

研究キーワード 1

  • 生物流体力学、バイオメカニクス、生体流動可視化計測、原生知能

研究分野 1

  • ものづくり技術(機械・電気電子・化学工学) / 流体工学 /

受賞 11

  1. 可視化情報学会 功労賞

    2023年5月 可視化情報学会

  2. 東北大学ディスティングイッシュトリサーチャー

    2020年4月 東北大学

  3. 文部科学大臣表彰若手科学者賞

    2018年4月 文部科学省

  4. 生体医工学シンポジウム ベストレビュワーアワード

    2017年9月15日 日本生体医工学会

  5. World Congress on Engineering 2016 Best Paper Awards

    2016年10月13日 International Association of Engineering

  6. 可視化情報シンポジウムアートコンテスト金賞

    2015年4月21日 可視化情報シンポジウム実行委員会

  7. 可視化情報学会映像賞

    2015年4月21日 可視化情報学会

  8. 可視化情報学会奨励賞(研究)

    2015年4月21日 可視化情報学会

  9. 日本機械学会賞奨励賞(研究)

    2015年4月17日 日本機械学会

  10. Measurement Science and Technology, Highlights of 2011-2012 Collection

    2012年8月16日 IOP Publishing

  11. 2007年生体医工学シンポジウムベストリサーチアワード

    2007年9月21日 日本生体医工学会

︎全件表示 ︎最初の5件までを表示

論文 76

  1. Glucose stockpile in the intestinal apical brush border in C. elegans

    Takumi Saito, Kenji Kikuchi, Takuji Ishikawa

    Biochemical and Biophysical Research Communications 706 2024年4月

    DOI: 10.1016/j.bbrc.2024.149762  

    ISSN:0006-291X

    eISSN:1090-2104

    詳細を見る 詳細を閉じる

    Revealing the mechanisms of glucose transport is crucial for studying pathological diseases caused by glucose toxicities. Numerous studies have revealed molecular functions involved in glucose transport in the nematode Caenorhabditis elegans, a commonly used model organism. However, the behavior of glucose in the intestinal lumen-to-cell remains elusive. To address that, we evaluated the diffusion coefficient of glucose in the intestinal apical brush border of C. elegans by using fluorescent glucose and fluorescence recovery after photobleaching. Fluorescent glucose taken in the intestine of worms accumulates in the apical brush border, and its diffusion coefficient of ∼10−8 cm2/s is two orders of magnitude slower than that in bulk. This result indicates that the intestinal brush border is a viscous layer. ERM-1 point mutations at the phosphorylation site, which shorten the microvilli length, did not significantly affect the diffusion coefficient of fluorescent glucose in the brush border. Our findings imply that glucose enrichment is dominantly maintained by the viscous layer composed of the glycocalyx and molecular complexes on the apical surface.

  2. High shear flow prevents bundling of bacterial flagella and induces lateral migration away from a wall

    Jinyou Yang, Kenji Kikuchi, Takuji Ishikawa

    Communications Physics 6 (1) 2023年12月

    DOI: 10.1038/s42005-023-01471-y  

    eISSN:2399-3650

    詳細を見る 詳細を閉じる

    Since the discovery of bacteria in the 17th century, bacterial motion has been the focus of great research interest. As an example of bacterial chemotaxis, Escherichia coli exhibits run-and-tumble motion by bundling and unbundling flagella, propelling the cells along a concentration gradient. However, the behavior of bacteria in high-shear flow environments remains poorly understood. In this study, we showed experimentally that E. coli swimming is severely inhibited at shear rates above a few hundred per second. Our simulations revealed that E. coli flagellar bundling cannot occur in a high-shear regime, because the background shear flow is stronger than the flagellar-generated flow required to form a bundle. Bacteria under strong shear behave like deformable objects and exhibit lateral migration away from a wall. These results suggest that bacteria that are unable to bundle their flagella in strong shear near a wall alter their locomotion strategy to passively escape from the wall.

  3. 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. 国際誌 査読有り

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

    Journal of clinical monitoring and computing 2023年6月8日

    DOI: 10.1007/s10877-023-01038-w  

    詳細を見る 詳細を閉じる

    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.

  4. Visualization of droplets and aerosols in simulated dental treatments to clarify the effectiveness of oral suction devices. 査読有り

    Jun Watanabe, Yoko Iwamatsu-Kobayashi, Kenji Kikuchi, Tomonari Kajita, Hiromitsu Morishima, Kensuke Yamauchi, Wataru Yashiro, Hidekazu Nishimura, Hiroyasu Kanetaka, Hiroshi Egusa

    Journal of prosthodontic research 2023年2月22日

    DOI: 10.2186/jpr.JPR_D_23_00013  

    詳細を見る 詳細を閉じる

    PURPOSE: The hazards of aerosols generated during dental treatments are poorly understood. This study aimed to establish visualization methods, discover conditions for droplets/aerosols generated in simulating dental treatments and identify the conditions for effective suction methods. METHODS: The spreading area was evaluated via image analysis of the droplets/aerosols generated by a dental air turbine on a mannequin using a light emitting diode (LED) light source and high-speed camera. The effects of different bur types and treatment sites, reduction effect of intra-oral suction (IOS) and extra-oral suction (EOS) devices, and effect of EOS installation conditions were evaluated. RESULTS: Regarding the bur types, a bud-shaped bur on the air turbine generated the most droplets/aerosols compared with round-shaped, round end-tapered, or needle-tapered burs. Regarding the treatment site, the area of droplets/aerosols produced by an air turbine from the palatal plane of the anterior maxillary teeth was significantly higher. The generated droplet/aerosol area was reduced by 92.1% by using IOS alone and 97.8% by combining IOS and EOS. EOS most effectively aspirated droplets/aerosols when placed close (10 cm) to the mouth in the vertical direction (0°). CONCLUSIONS: The droplets/aerosols generated by an air turbine could be visualized using an LED light and a high-speed camera in simulating dental treatments. The bur shape and position of the dental air turbine considerably influenced droplet/aerosol diffusion. The combined use of IOS and EOS at a proper position (close and perpendicular to the mouth) facilitated effective diffusion prevention to protect the dental-care environment.

  5. Endotracheal tube, by the venturi effect, reduces the efficacy of increasing inlet pressure in improving pendelluft. 国際誌 査読有り

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

    PloS one 18 (9) e0291319 2023年

    DOI: 10.1371/journal.pone.0291319  

    詳細を見る 詳細を閉じる

    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.

  6. Reciprocating intestinal flows enhance glucose uptake in C. elegans. 国際誌 査読有り

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

    Scientific reports 12 (1) 15310-15310 2022年9月21日

    DOI: 10.1038/s41598-022-18968-1  

    詳細を見る 詳細を閉じる

    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.

  7. Rheotaxis and migration of an unsteady microswimmer 査読有り

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

    Journal of Fluid Mechanics 930 2022年1月10日

    出版者・発行元:Cambridge University Press (CUP)

    DOI: 10.1017/jfm.2021.921  

    ISSN:0022-1120

    eISSN:1469-7645

    詳細を見る 詳細を閉じる

    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.

  8. Influence of Respiratory Gas Density on Tidal Volume During Pressure-Controlled Ventilation: A Laboratory Investigation and Observational Study in Children. 査読有り

    Tohoku Journal of Experimental Medicine 256 (4) 271-281 2022年

    DOI: 10.21203/rs.3.rs-711979/v1  

  9. Microbial Brazil nut effect. 国際誌 査読有り

    Atul Srivastava, Kenji Kikuchi, Takuji Ishikawa

    Soft matter 17 (46) 10428-10436 2021年12月1日

    DOI: 10.1039/d1sm01327k  

    詳細を見る 詳細を閉じる

    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.

  10. Non-biodegradable objects can boost microbial growth in water bodies by harnessing bubbles 査読有り

    Atul Srivastava, Kenji Kikuchi, Takuji Ishikawa

    Royal Society Open Science 8 (210646) 1-15 2021年9月

    DOI: 10.1098/rsos.210646  

  11. Bacterial biomechanics-From individual behaviors to biofilm and the gut flora. 国際誌 査読有り

    Takuji Ishikawa, Toshihiro Omori, Kenji Kikuchi

    APL bioengineering 4 (4) 041504-041504 2020年12月

    DOI: 10.1063/5.0026953  

    詳細を見る 詳細を閉じる

    Bacteria inhabit a variety of locations and play important roles in the environment and health. Our understanding of bacterial biomechanics has improved markedly in the last decade and has revealed that biomechanics play a significant role in microbial biology. The obtained knowledge has enabled investigation of complex phenomena, such as biofilm formation and the dynamics of the gut flora. A bottom-up strategy, i.e., from the cellular to the macroscale, facilitates understanding of macroscopic bacterial phenomena. In this Review, we first cover the biomechanics of individual bacteria in the bulk liquid and on surfaces as the base of complex phenomena. The collective behaviors of bacteria in simple environments are next introduced. We then introduce recent advances in biofilm biomechanics, in which adhesion force and the flow environment play crucial roles. We also review transport phenomena in the intestine and the dynamics of the gut flora, focusing on that in zebrafish. Finally, we provide an overview of the future prospects for the field.

  12. The bubble-induced population dynamics of fermenting yeasts. 国際誌 査読有り

    Atul Srivastava, Kenji Kikuchi, Takuji Ishikawa

    Journal of the Royal Society, Interface 17 (172) 20200735-20200735 2020年11月

    DOI: 10.1098/rsif.2020.0735  

    詳細を見る 詳細を閉じる

    Bubble-induced transport is a ubiquitous natural and industrial phenomenon. In brewery, such transport occurs due to gas bubbles generated through anaerobic fermentation by yeasts. Two major kinds of fermentation viz. top (ale) and bottom (lager) fermentation, display a difference in their yeast distributions inside a sugar broth. The reason for this difference is believed to be yeast-bubble adhesion arising due to surface hydrophobicity of the yeast cell wall; however, the physical mechanism is still largely a mystery. In this report, through in vivo experiments, we develop a novel theoretical model for yeast distribution based on the general conservation law. This work clarifies that bubble-induced diffusion is the dominant transport mechanism in bottom-fermentation by lagers whereas, yeast-bubble adhesion plays a leading role in transporting ales in top-fermentation, thereby corroborating the centuries-old belief regarding distribution difference in yeast population in two kinds of fermentation.

  13. Vulnerability of the skin barrier to mechanical rubbing. 国際誌 査読有り

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

    International journal of pharmaceutics 587 119708-119708 2020年7月31日

    DOI: 10.1016/j.ijpharm.2020.119708  

    詳細を見る 詳細を閉じる

    Skin barrier function is the battlefront for preventing permeation of harmful substances and infectious diseases. However, it can be destroyed by mechanical forces, as shown in many studies. Excess rubbing may increase the permeability of the skin to aqueous material. Although the skin barrier plays an important physiological role in humans, the vulnerability of skin to mechanical rubbing is poorly understood. Therefore, we investigated the effects of rubbing on the skin in vitro; skin damage was quantified by laser-induced fluorescence. Microscopic observation showed that keratinocytes in the stratum corneum sustained traumatic damage, which reduced the barrier function in that region. The permeability of the skin to an aqueous solution increased with rubbing frequency and load, and rubbing markedly reduced the barrier function of the stratum corneum. To understand the mechanisms underlying the skin damage, we developed a simple mathematical model assuming that the skin is a viscoelastic material. We hypothesized that the increased skin permeability was caused by the damage sustained by keratinocytes in the stratum corneum, and that the permeability was proportional to the time-averaged strain. Our theoretical results showed quantitative agreement with the experimental results and illustrated that rubbing and strain relaxation play key roles in rubbing-induced permeation.

  14. How do C. elegans worms survive in highly viscous habitats? 国際誌 査読有り

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

    The Journal of experimental biology 2020年6月25日

    DOI: 10.1242/jeb.224691  

    詳細を見る 詳細を閉じる

    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.

  15. Mechanical roles of anterograde and retrograde intestinal peristalses after feeding in a larval fish (Danio rerio). 国際誌 査読有り

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

    American journal of physiology. Gastrointestinal and liver physiology 318 (6) G1013-G1021 2020年6月1日

    DOI: 10.1152/ajpgi.00165.2019  

    詳細を見る 詳細を閉じる

    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 h, 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 h 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.NEW & NOTEWORTHY Transport in gut is important, not only for digestion, metabolism, and nutrient uptake, but also for microbiotic circumstance; however, hydrodynamic effects in the intestine have not been fully clarified. We provide the first quantitative evidence of the mechanical roles of anterograde and retrograde intestinal peristalses in the larval fish of Danio rerio by adopting physical parameters of diffusivity and pressure rise. The intestine transitionally regulates mixing and pumping functions by peristaltic propagations after feeding.

  16. Cilia and centrosomes: Ultrastructural and mechanical perspectives. 国際誌 査読有り

    Takuji Ishikawa, Hironori Ueno, Toshihiro Omori, Kenji Kikuchi

    Seminars in cell & developmental biology 110 61-69 2020年4月16日

    出版者・発行元:Elsevier BV

    DOI: 10.1016/j.semcdb.2020.03.007  

    ISSN:1084-9521

    eISSN:1096-3634

    詳細を見る 詳細を閉じる

    Cilia and centrosomes of eukaryotic cells play important roles in cell movement, fluid transport, extracellular sensing, and chromosome division. The physiological functions of cilia and centrosomes are generated by their dynamics, motions, and forces controlled by the physical, chemical, and biological environments. How an individual cilium achieves its beat pattern and induces fluid flow is governed by its ultrastructure as well as the coordination of associated molecular motors. Thus, a bottom-up understanding of the physiological functions of cilia and centrosomes from the molecular to tissue levels is required. Correlations between the structure and motion can be understood in terms of mechanics. This review first focuses on cilia and centrosomes at the molecular level, introducing their ultrastructure. We then shift to the organelle level and introduce the kinematics and mechanics of cilia and centrosomes. Next, at the tissue level, we introduce nodal ciliary dynamics and nodal flow, which play crucial roles in the organogenetic process of left-right asymmetry. We also introduce respiratory ciliary dynamics and mucous flow, which are critical for protecting the epithelium from drying and exposure to harmful particles and viruses, i.e., respiratory clearance function. Finally, we discuss the future research directions in this field.

  17. The shape effect of flagella is more important than bottom-heaviness on passive gravitactic orientation in Chlamydomonas reinhardtii. 国際誌 査読有り

    Azusa Kage, Toshihiro Omori, Kenji Kikuchi, Takuji Ishikawa

    The Journal of experimental biology 223 (Pt 5) 2020年3月3日

    DOI: 10.1242/jeb.205989  

    詳細を見る 詳細を閉じる

    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.

  18. Particle selectivity of filtering by C. elegans 査読有り

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

    THEORETICAL AND APPLIED MECHANICS LETTERS 9 (2) 61-65 2019年3月

    出版者・発行元:ELSEVIER SCIENCE BV

    DOI: 10.1016/j.taml.2019.02.001  

    ISSN:2095-0349

    詳細を見る 詳細を閉じる

    A nematode Caenorhabditis elegans (C. elegans) is a filter feeder, which draws a suspension of bacteria and separates bacteria from the solvent by using pharyngeal pumping motions and specific mouth parts. This mechanism has not been fully understood. We investigated the mechanism of filtering of bacteria in the pharynx of C. elegans by visualization by fluorescent particles and dyed E. coli. We succeeded in quantifying the selectivity of bacteria-sized particles by C. elegans. The most accumulated particles were those of 0.5 mu m in diameter. The quantity of accumulated particles of 0.2 mu m or 1.0 mu m in diameter was about one third of that of particles of 0.5 mu m in diameter. The least accumulated particles were those of 0.05 mu m in diameter. These results suggest that the pharyngeal structures of C. elegans would be suitable for eating bacteria because the size of bacteria ingested by C. elegans worms is about 0.5 mu m in diameter. We also succeeded in visualizing pharyngeal structures and pumping motions and flow in the pharynx. We found that there were phase differences in the motions among procorpus, metacorpus and isthmus. This result suggests filtering would occur at the two tips of procorpus and isthmus by the phase differences. We found that bacteria-sized particles and bacteria were flowed and trapped in the channels, which existed along the central lumen from tip of procorpus to isthmus. From our results, we proposed the novel mechanism of filtering of bacteria through the channels for flowing and trapping. In future, this selective filtering mechanism of C. elegans would be applied to development of microfluidic filtration devices for medical and biological equipment. (C) 2019 The Authors. Published by Elsevier Ltd on behalf of The Chinese Society of Theoretical and Applied Mechanics.

  19. Depth measurement of molecular permeation using inclined confocal microscopy. 国際誌 査読有り

    Kenji Kikuchi, Shunsuke Shigeta, Takuji Ishikawa

    PloS one 14 (3) e0214504 2019年

    DOI: 10.1371/journal.pone.0214504  

    詳細を見る 詳細を閉じる

    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.

  20. Burst mode pumping: A new mechanism of drinking in mosquitoes 査読有り

    Kenji Kikuchi, Mark A. Stremler, Souvick Chatterjee, Wah-Keat Lee, Osamu Mochizuki, John J. Socha

    Scientific Reports 8 (1) 4885 2018年12月1日

    出版者・発行元:Nature Publishing Group

    DOI: 10.1038/s41598-018-22866-w  

    ISSN:2045-2322

    詳細を見る 詳細を閉じる

    Mosquitoes transport liquid foods into the body using two muscular pumps in the head. In normal drinking, these pumps reciprocate in a stereotyped pattern of oscillation, with a high frequency but small stroke volume. Do mosquitoes modulate their neuromotor programs for pumping to produce different drinking modes? More broadly, what are the mechanical consequences of a two-pump system in insects? To address these questions, we used synchrotron x-ray imaging and fluid mechanical modeling to investigate drinking performance in mosquitoes. X-ray imaging of the pumps during drinking revealed two modes of pumping: continuous reciprocation with multiple small strokes, and a newly discovered 'burst mode' involving a single, large-volume stroke. Results from modeling demonstrate that burst mode pumping creates a very large pressure drop and high volume flow rate, but requires a massive increase in power, suggesting that continuous pumping is more economical for drinking. Modeling also demonstrates that, from one mode of pumping to the other, the mechanical role of the individual pumps changes. These results suggest that the advantage of a two-pump system in insects lies in its flexibility, enabling the animal to pump efficiently or powerfully as demanded by environmental considerations.

  21. Collective spreading of red blood cells flowing in a microchannel. 国際誌

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

    Journal of biomechanics 69 64-69 2018年3月1日

    DOI: 10.1016/j.jbiomech.2018.01.009  

    ISSN:0021-9290

    詳細を見る 詳細を閉じる

    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.

  22. Biomechanics of Tetrahymena escaping from a dead end 査読有り

    Takuji Ishikawa, Kenji Kikuchi

    Proceedings of the Royal Society B: Biological Sciences 285 (1873) 2018年2月28日

    出版者・発行元:Royal Society Publishing

    DOI: 10.1098/rspb.2017.2368  

    ISSN:1471-2954 0962-8452

    詳細を見る 詳細を閉じる

    Understanding the behaviours of swimming microorganisms in various environments is important for understanding cell distribution and growth in nature and industry. However, cell behaviour in complex geometries is largely unknown. In this study, we used Tetrahymena thermophila as a model microorganism and experimentally investigated cell behaviour between two flat plates with a small angle. In this configuration, the geometry provided a ‘dead end’ line where the two flat plates made contact. The results showed that cells tended to escape from the dead end line more by hydrodynamics than by a biological reaction. In the case of hydrodynamic escape, the cell trajectories were symmetric as they swam to and from the dead end line. Near the dead end line, T. thermophila cells were compressed between the two flat plates while cilia kept beating with reduced frequency those cells again showed symmetric trajectories, although the swimming velocity decreased. These behaviours were well reproduced by our computational model based on biomechanics. The mechanism of hydrodynamic escape can be understood in terms of the torque balance induced by lubrication flow. We therefore conclude that a cell’s escape from the dead end was assisted by hydrodynamics. These findings pave the way for understanding cell behaviour and distribution in complex geometries.

  23. Biomechanics of Tetrahymena escaping from dead ends

    TAKUJI ISHIKAWA, KENJI KIKUCHI

    Bulletin of the American Physical Society DFD2017 62 (14) 407-407 2017年11月

  24. Effect of Fluid Viscosity on the Cilia-Generated Flow on a Mouse Tracheal Lumen 査読有り

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

    ANNALS OF BIOMEDICAL ENGINEERING 45 (4) 1048-1057 2017年4月

    出版者・発行元:SPRINGER

    DOI: 10.1007/s10439-016-1743-y  

    ISSN:0090-6964

    eISSN:1573-9686

    詳細を見る 詳細を閉じる

    Mucous flow in a tracheal lumen is generated by the beat motion of ciliated cells to provide a clearance function by discharging harmful dust particles and viruses. Due to its physiological importance, the cilia-generated flow and the rheological properties of mucus have been investigated intensively. The effects of viscosity on the cilia-generated flow, however, have not been fully clarified. In this study, we measured bulk background velocity of ciliary flow using a micro particle tracking velocimetry method under various viscosity conditions in mice. The results showed that the flow velocity decreased as the increase with viscosity of ambient fluid. Moreover, no previous study has clarified the pump power generated by cilia, which provides important information with regard to understanding the molecular motor properties of cilia. Measurements of both the ciliary flow and the ciliary motion were conducted to determine the cilia pump power. Our results indicated that the cilia pump during the effective stroke did not drive the ciliary flow efficiently under high viscosity conditions; these findings are necessary to resolve the clearance function.

  25. Sponge Pump

    HÉLÈNE DE MALEPRADE, KENJI KIKUCHI, RAYMOND E. GOLDSTEIN

    Flow17 2017年

  26. Transdermal Drug Delivery Enhancement by Unidirectional Skin Extention

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

    The 26th Congress of the International Society of Biomechanics 2017年

  27. ViscousLload Change 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 2017年

  28. 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年4月

    出版者・発行元:SPRINGER

    DOI: 10.1007/s10439-016-1570-1  

    ISSN:0090-6964

    eISSN:1573-9686

  29. Inhomogeneous distribution of Chlamydomonas in a cylindrical container with a bubble plume 査読有り

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

    BIOLOGY OPEN 5 (2) 154-160 2016年2月

    出版者・発行元:COMPANY OF BIOLOGISTS LTD

    DOI: 10.1242/bio.015669  

    ISSN:2046-6390

    詳細を見る 詳細を閉じる

    Swimming microalgae show various taxes, such as phototaxis and gravitaxis, which sometimes result in the formation of a cell-rich layer or a patch in a suspension. Despite intensive studies on the effects of shear flow and turbulence on the inhomogeneous distribution of microalgae, the effect of a bubble plume has remained unclear. In this study, we used Chlamydomonas as model microalgae, and investigated the spatial distribution of cells in a cylindrical container with a bubble plume. The results illustrate that cells become inhomogeneously distributed in the suspension due to their motility and photo-responses. A vortical ring distribution was observed below the free surface when the bubble flow rate was sufficiently small. We performed a scaling analysis on the length scale of the vortical ring, which captured the main features of the experimental results. These findings are important in understanding transport phenomena in a microalgae suspension with a bubble plume.

  30. Bio-Micropump by Using A Flagellate Propulsive Force of Escherichia coli 査読有り

    Kenji Kikuchi, Ryo Matsuura, Hironori Ueno, Yohsuke Imai, Noriaki Matsuki, Takami Yamaguchi, Takuji Ishikawa

    The World Congress on Engineering 2016 ICSBB15 515-518 2016年

  31. Diffusive Promotion by Velocity Gradient of Cytoplasmic Streaming (CPS) in Nitella Internodal Cells 査読有り

    Kenji Kikuchi, Osamu Mochizuki

    PLOS ONE 10 (12) 0144938-1-12 2015年12月

    出版者・発行元:PUBLIC LIBRARY SCIENCE

    DOI: 10.1371/journal.pone.0144938  

    ISSN:1932-6203

    詳細を見る 詳細を閉じる

    Cytoplasmic streaming (CPS) is well known to assist the movement of nutrients, organelles and genetic material by transporting all of the cytoplasmic contents of a cell. CPS is generated by motility organelles that are driven by motor proteins near a membrane surface, where the CPS has been found to have a flat velocity profile in the flow field according to the sliding theory. There is a consistent mixing of contents inside the cell by CPS if the velocity gradient profile is flattened, which is not assisted by advection diffusion but is only supported by Brownian diffusion. Although the precise flow structure of the cytoplasm has an important role for cellular metabolism, the hydrodynamic mechanism of its convection has not been clarified. We conducted an experiment to visualise the flow of cytoplasm in Nitella cells by injecting tracer fluorescent nanoparticles and using a flow visualisation system in order to understand how the flow profile affects their metabolic system. We determined that the velocity field in the cytosol has an obvious velocity gradient, not a flattened gradient, which suggests that the gradient assists cytosolic mixing by Taylor-Aris dispersion more than by Brownian diffusion.

  32. 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年9月1日

  33. 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年9月1日

  34. Velocity profile of thin film flows measured using a confocal microscopy particle image velocimetry system with simultaneous multi depth position 査読有り

    K. Kikuchi, O. Mochizuki

    MEASUREMENT SCIENCE AND TECHNOLOGY 26 (2) 025301-1-8 2015年2月

    出版者・発行元:IOP PUBLISHING LTD

    DOI: 10.1088/0957-0233/26/2/025301  

    ISSN:0957-0233

    eISSN:1361-6501

    詳細を見る 詳細を閉じる

    In this paper, we report a technique for simultaneously visualizing flows near walls at nanodepth positions. To achieve such a high interval of depth gradient, we developed a tilted observation technique in a particle image velocimetry (PIV) system based on confocal microscopy. The focal plane along the bottom of the flow channel was tilted by tilting the micro-channel, enabling depth scanning in the microscopic field of view. Our system is suitable for measuring 3D two-component flow fields. The depth interval was approximately 220 nm over a depth range of 10 mu m, depending on the tilt angle of the micro-channel. Applying the proposed system, we visualized the near-wall flow in a drainage film flow under laminar conditions to the depth of approximately 30 mu m via vertical scanning from the bottom to the free surface. The velocity gradient was proportional to the distance from the wall, consistent with theoretical predictions. From the measured near-wall velocity gradient, we calculated the wall shear stress. The measurement accuracy was approximately 1.3 times higher in our proposed method than in the conventional confocal micro-PIV method.

  35. Hemodynamics in the Microcirculation and in Microfluidics

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

    ANNALS OF BIOMEDICAL ENGINEERING 43 (1) 238-257 2015年1月

    出版者・発行元:SPRINGER

    DOI: 10.1007/s10439-014-1180-8  

    ISSN:0090-6964

    eISSN:1573-9686

    詳細を見る 詳細を閉じる

    Hemodynamics in microcirculation is important for hemorheology and several types of circulatory disease. Although hemodynamics research has a long history, the field continues to expand due to recent advancements in numerical and experimental techniques at the micro-and nano-scales. In this paper, we review recent computational and experimental studies of blood flow in microcirculation and microfluidics. We first focus on the computational studies of red blood cell (RBC) dynamics, from the single cellular level to mesoscopic multiple cellular flows, followed by a review of recent computational adhesion models for white blood cells, platelets, and malaria-infected RBCs, in which the cell adhesion to the vascular wall is essential for cellular function. Recent developments in optical microscopy have enabled the observation of flowing blood cells in microfluidics. Experimental particle image velocimetry and particle tracking velocimetry techniques are described in this article. Advancements in micro total analysis system technologies have facilitated flowing cell separation with microfluidic devices, which can be used for biomedical applications, such as a diagnostic tool for breast cancer or large intestinal tumors. In this paper, cell-separation techniques are reviewed for microfluidic devices, emphasizing recent advances and the potential of this fast-evolving research field in the near future.

  36. 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年

  37. Noninvasive Measurement of Drug Permeation in the Skin

    Shunsuke Shigeta, Kenji Kikuchi, Keiko Numayama, Takuji Ishikawa

    The 8th Asian-Pacific Conference on Biomechanics 2015年

  38. 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 2015年

  39. Measurement of Drug Permeation in the Skin by a Two Photon Microscopy

    Shunsuke Shigeta, Kenji Kikuchi, Keiko Numayama, Takuji Ishikawa

    The 22nd Congress of the European Society of Biomechanics 2015年

  40. 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年7月5日

  41. Micro PIV measurement of slip flow on a hydrogel surface 査読有り

    K. Kikuchi, O. Mochizuki

    MEASUREMENT SCIENCE AND TECHNOLOGY 25 (6) 065702-1-632 2014年6月

    出版者・発行元:IOP PUBLISHING LTD

    DOI: 10.1088/0957-0233/25/6/065702  

    ISSN:0957-0233

    eISSN:1361-6501

    詳細を見る 詳細を閉じる

    Slip flow on a hydrogel surface was investigated in order to clarify the effect of drag reduction on the aqueous surface of living things. Thin-film flow along the hydrogel surface was measured by using a micro PIV (particle image velocimetry) system for comparison with theoretical velocity distribution which satisfied the non-slip condition on a solid surface. The slip flow on the hydrogel was found to be related to the degree of swelling and molecular weight of the hydrogel materials. This shows the possibility of a reduction in wall shear stress as a result of the decrease in the velocity gradient near a wall surface.

  42. Morphological considerations of fish fin shape on thrust generation 査読有り

    K. Kikuchi, Y. Uehara, Y. Kubota, O. Mochizuki

    Journal of Applied Fluid Mechanics 7 (4) 625-632 2014年

    DOI: 10.36884/jafm.7.04.21358  

    ISSN:1735-3572

    eISSN:1735-3645

    詳細を見る 詳細を閉じる

    In this study, we aimed to determine the relationship between thrust generation and fish fin shape. To compare the effect fin shape had on thrust generation, we categorized the morphological shapes of fish fins into equilateral polygonal shapes. Polygonal fins were used to generate thrust that depended only on shape. These fins were constructed of a hard elastic material to eliminate any influence of shape deformation. A servomotor with a reciprocal rotation moved a fin cyclically, and thrust was experimentally measured using a strain gage system. Thrust tended to be proportional to the inertia moment of a fin, which indicated difficulty with rotation. Moreover, this trend for thrust generation was directly related to the number of apexes of a polygonal fin. The force translated ratio, which was thrust divided by the force required for fin rotation, was evaluated to determine the hydrodynamic characteristics of fins. This finding showed that the force translated ratio of a fin increased with increased movable perimeter length. The greatest thrust was generated by a triangular fin rotated at its apex, which is often seen in general fish tail fins, whereas the hydrodynamic characteristics were the worst in polygonal fins.

  43. Some remarks on surface conditions of solid body plunging into water with particle method 査読有り

    Masao Yokoyama, Yoshihiro Kubota, Kenji Kikuchi, Genki Yagawa, Osamu Mochizuki

    Advanced Modeling and Simulation in Engineering Science 1 (9) 1-14 2014年

  44. Effect of Rheological Properties on Cilliary Flow in the Airway

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

    International Symposium on Integrated Nanobiomechanics 23-24 2014年

  45. In Vivo Visualization of Cytoplasmic Streaming by Using Confocal Micro PTV Measurement

    Kenji Kikuchi, Osamu Mochizuki

    International Symposium on Integrated Nanobiomechanics 25-26 2014年

  46. Falling dynamics of immobilized Chlamydomonas reinhardtii

    Azusa Kage, Kenji Kikuchi, Takuji Ishikawa

    The Sixth International Symposium on Aero Aqua Bio-mechanisms2014 16-17 2014年

  47. 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-mechanisms2014 39-40 2014年

  48. 水中を落下する球に作用する非定常抵抗の係数

    菊地謙次, 今野友博, 市川誠司, 窪田佳寛, 望月修

    日本機械学会論文集 B編(Web) 79 (798) WEB ONLY 151-163-163 2013年

    出版者・発行元:The Japan Society of Mechanical Engineers

    DOI: 10.1299/kikaib.79.151  

    ISSN:1884-8346

    eISSN:1884-8346

    詳細を見る 詳細を閉じる

    The purpose of this study is to know differences between steady and unsteady drag coefficients of a sphere. Though we often have to estimate unsteady drag-forces acting on a moving obstacle, we are obliged to use the well-known steady drag coefficient for the first estimation because of lack of information about effects of unsteadiness on the drag coefficient. The usual way to take account of unsteadiness is an added mass. However, its application is restricted within the simple shape of an obstacle. We propose a way based on the equation of motion to obtain the unsteady drag coefficient. To confirm validity of the way, we measured and analyzed the motion of the falling sphere in water by using a high-speed camera and a motion capture method. The drag coefficients as a function of time were obtained by substituting measured values of velocity and acceleration into the equation of motion. The drag coefficient was 0.52 when the sphere attains the terminal velocity, being quite large at the beginning of motion. Comparing with the values obtained by the other previous studies, our result is reasonable.

  49. Effects of slip condition on flow near the surface of hydro-gel

    M. Yokoyama, Y. Kubota, K. Kikuchi, O. Mochizuki, G. Yagawa

    Computational Methods for Coupled Problems in Science and Engineering V - A Conference Celebrating the 60th Birthday of Eugenio Onate, COUPLED PROBLEMS 2013 643-650 2013年

    詳細を見る 詳細を閉じる

    The influence of surface properties of a wall of the body on the flow behavior is investigated numerically by the Moving Particle Semi-implicit (MPS) method. Considering the difference between the no-slip condition and the with-slip condition of a wall, a new method to calculate the flow near the hydro-gel wall and that inside the hydro-gel is proposed in this paper.

  50. 水中を落下する球に作用する非定常抵抗の係数 査読有り

    菊地謙次, 今野友博, 市川誠司, 窪田佳寛, 望月修

    日本機械学会論文集B編 79 (798) 151-163 2013年

    DOI: 10.1299/kikaib.79.151  

    ISSN:0387-5016

  51. 物体壁面の表面性状を考慮した流れのシミュレーション 査読有り

    横山真男, 菊地謙次, 窪田佳寛, 望月修

    ながれ;日本流体力学会誌 32 (4) 319-326 2013年

    出版者・発行元:日本流体力学会

    ISSN:0286-3154

  52. Visualization of Cytoplasmic Streaming 査読有り

    Kenji Kikuchi, Narihisa Suzuki, Osamu Mochizuki

    The 14th Asia Congress of Fluid Mechanics 16 (5) 1-4 2013年

  53. Near wall flow visualization by inclined-observation using confocal micro PIV method

    K Kikuchi, O Mochizuki

    The 12th International Symposium on Fluid Control, Measurement and Visualization 2013年

  54. Multi-modal pumping in drinking mosquitoes

    K. Kikuchi, S. Chatterjee, W. -K Lee, M. A. Stremler, O. Mochizuki, J. J. Socha, U. Toyo

    INTEGRATIVE AND COMPARATIVE BIOLOGY 52 E93-E93 2012年4月

    出版者・発行元:OXFORD UNIV PRESS INC

    ISSN:1540-7063

  55. Fluid dynamics on fish’s tail fin

    Kenji Kikuchi, Yusuke Uehara, Yoshihiro Kubota, Osamu Mochizuki

    The 5th International Symposium on Aero Aqua Bio-Mechanisms 2012年

  56. Measurement of water-movement on a hydrogel

    Kenji KIKUCHI, Osamu MOCHIZUKI

    The 8th KSME-JSME Thermal and Fluids Engineering Conference 2012年

  57. Drag coefficient of an accelerated sphere

    Kenji KIKUCHI, Tomohiro KONNO, Seiji ICHIKAWA, Yoshihiro KUBOTA, Osamu MOCHIZUKI

    Joint international conference of ISEM-ACEM-SEM-7th ISEM12 2012年

  58. Micro-PIV (micro particle image velocimetry) visualization of red blood cells (RBCs) sucked by a female mosquito 招待有り 査読有り

    K. Kikuchi, O. Mochizuki

    MEASUREMENT SCIENCE AND TECHNOLOGY 22 (6) 064002-1-9 2011年6月

    出版者・発行元:IOP PUBLISHING LTD

    DOI: 10.1088/0957-0233/22/6/064002  

    ISSN:0957-0233

    eISSN:1361-6501

    詳細を見る 詳細を閉じる

    A mosquito's pump is a highly effective system in the small suction domain. To understand a mosquito's blood suction mechanism, we analysed the characteristics of red blood cells (RBCs) in human blood during and after suction by a female mosquito. Focussing on the flow patterns of the RBCs in human blood being sucked by a mosquito, we visualized blood flow by using a micro-particle image velocimetry (mu-PIV) system, which combines an optical microscope and a PIV method. In an ex vivo experiment, a female mosquito was supplied diluted blood at the tip of the proboscis. We examined the blood flow around the tip of the proboscis and observed that RBCs were periodically sucked towards a hole around the tip. The sucked RBCs then homogeneously flowed parallel to the inner surface of the proboscis without adhering to the wall. Furthermore, using a bioelectric recording system, we directly measured electrical signals generated during suction by the pump muscles located in the mosquito's head. We found that the electrical signal power was synchronized with the acceleration of the RBCs in the sucking phase. A histological stain method was adapted for the observation of the form and internal structure of RBCs in the mosquito. Although the blood flow analysis revealed that the RBCs underwent shear stress during suction, RBCs in the mosquito's stomach maintained their original shape.

  59. Study of the pump of a mosquito 査読有り

    Kenji Kikuchi, Osamu Mochizuki

    ASME-JSME-KSME 2011 Joint Fluids Engineering Conference, AJK 2011 1 (D) 2001-2007 2011年

    DOI: 10.1115/AJK2011-19003  

    詳細を見る 詳細を閉じる

    Structures and functions of a mosquito's pump system were investigated experimentally to clarify the mechanistic aspects of this optimized bio-pump. The three-dimensional strucure of the pump that was reconstructed by 1500 slices of the mosquito's head was obtained using a histopathological method. The mosquito's pump motion is predictable, and the pump volume can be estimated by the three-dimensional structural observations. The pump volume of the pumps, an oral cavity pump and pharynx pump, were estimated as being 7.92×10 -4mm3, 63.3×10--4mm3 respectively. The frequency of the mosquito's pumps was predicted to be 2.09-16.7 Hz, and was estimated using the pump volume and the volumetric blood flow rate. The motion of the mosquito's pumps was visualized directly by an x-ray phase contrast imaging method using synchrotron radiation. It was found that the mosquito's pumps (i.e., the oral cavity pump and the pharynx pump) worked alternately with a 4.23 Hz pump frequency. Moreover, the phase difference of each pump was almost 0.5, suggesting that the mosquito's pumps worked in opposite phases. In addition, the mosquito's pumps were found to work as a inline pump, which is suitable for increasing the pressure head of pump. Copyright © 2011 by ASME.

  60. Thrust of a thin plate starting impulsively 査読有り

    Seiji Ichikawa, Kenji Kikuchi, Osamu Mochizuki

    ASME-JSME-KSME 2011 Joint Fluids Engineering Conference, AJK 2011 1 (D) 2857-2862 2011年

    DOI: 10.1115/AJK2011-16004  

    詳細を見る 詳細を閉じる

    We studied on a vortex ring generated by a suddenly accelerated thin plate to understand a relation between the circulation and necessary force to accelerate the thin plate. The motion of thin plate is operated by trust force. We measured velocity fields around a circular disk, using a PIV system and high speed CMOS camera. We showed that the time derivative of the circulation related to the force to drive the disk because the disk gave energy impulsively to the vortex ring. This gives us the way to estimate thrust if we could measure the change in circulation of the starting vortex ring by the disk. We applied it to the estimation of thrust by an accelerated non-circular disk by introducing an equivalent circle that has the same area as the non-circular disk. Copyright © 2011 by ASME.

  61. S0502-4-4 急加速する板の後流([S0502-4]噴流,後流および剥離流れ現象の解明と制御(4))

    市川 誠司, 菊地 謙次, 望月 修

    年次大会講演論文集 2010 185-186 2010年

    出版者・発行元:一般社団法人日本機械学会

    DOI: 10.1299/jsmemecjo.2010.2.0_185  

    詳細を見る 詳細を閉じる

    We studied on a vortex ring generated by a suddenly accelerated disk to understand a relation between the circulation and necessary force to accelerate the disk. To estimate a propulsive force of small swimming animals is our motivation. We measured velocity fields using a PIV system and high speed CMOS camera around a circular disk as a model of a fin and paddle. We showed that the time derivative of the circulation related to the force to drive the disk. Thus, the disk gives energy impulsively to the vortex ring. This gives us the way to estimate thrust if we could measure the change in circulation of the starting vortex ring by the disk. We applied it to the estimation of thrust by an accelerated non-circular disk by introducing an equivalent circle that has the same area as the non-circular disk.

  62. J0205-4-3 生体を模擬したハイドロゲル上の流れ([J0205-4]バイオメカニズム/バイオミメティクス/バイオインスパイアー(4))

    菊地 謙次, 市川 誠司, 望月 修

    年次大会講演論文集 2010 69-70 2010年

    出版者・発行元:一般社団法人日本機械学会

    DOI: 10.1299/jsmemecjo.2010.6.0_69  

    詳細を見る 詳細を閉じる

    The purpose of our study is to know the interaction between a flow and a surface of hydro gel. Tissue of living organ like blood vessel, cartilage and eyeball is a hydro gel. It contains water, so that the surface of hydro gel is considered to be water. Thus, it is a hydrophilic material. We expect it to show good reduction of friction if we use it the wall of a conduit. To check the concept, we measured velocity profile of a film flow on the hydro gel by a micro PIV method, estimating wall share stress from the velocity gradient at the wall. We confirmed slip-velocity depending on degree of swelling of hydro gel and the flow inside of gel induced by shear stress.

  63. アメンボはなぜ浮けるのか 査読有り

    望月修, 菊地謙次

    可視化情報学会誌 30 (119) 232-237 2010年

    DOI: 10.3154/jvs.30.028  

  64. Consideration of thrust in escaping motion of a mosquito larva 査読有り

    Kenji Kikuchi, Osamu Mochizuki

    Journal of Aero Aqua Bio-mechanism 1 (1) 111-116 2010年

    出版者・発行元:Society of Aero Aqua Bio-mechanisms

    DOI: 10.5226/jabmech.1.111  

    ISSN:2185-1522

    詳細を見る 詳細を閉じる

    Purpose of this study is to understand a thrust generation mechanism of a swimming mosquito larva. A quick escaping swimming behaved in their dangerous situations. A time-varying motion of a tail related a thrust was investigated by a motion capture method. Moreover, the velocity fields around the tail were measured by micro Particle Image Velocimetry (PIV) system. It was found that their unique wriggling motion generated the thrust in all sequence whereby an effective utilization of a vortex ring. The convenient way to estimate the thrust according to kinetic energy of the vortex ring was proposed in this paper.

  65. A flow on a hydrogel surface mimicked a living cell

    Kenji KIKUCHI, Osamu MOCHIZUKI

    The 21st International Symposium on Transport Phenomena 2010年

  66. Visualization of RBC sucked by female mosquito

    Kenji KIKUCHI, Osamu MOCHIZUKI

    The 14th International Symposium on Flow Visualization 2010年

  67. J0202-2-5 動物プランクトン-ボウフラ-の遊泳(生物の機能・運動と模倣(1))

    菊地 謙次, 望月 修

    年次大会講演論文集 2009 145-146 2009年

    出版者・発行元:一般社団法人日本機械学会

    DOI: 10.1299/jsmemecjo.2009.6.0_145  

    詳細を見る 詳細を閉じる

    The purpose of our study is to analyze swimming motion of a mosquito larva which is well called as a wriggler. When it meets some dangerous situations, it escapes actively from air-water surface to bottom with rapid swimming motion. A swimming thrust is obtained by a paddling motion of its tail fin with a separation of a vortex in the power stroke. We measured velocity vector fields around the body and wake by micro PIV measurements. It was found that a snapping motion of its tail fin yielded thrust.

  68. Swimming motion of a mosquito larva

    Kenji KIKUCHI, Osamu MOCHIZUKI

    The 4th International Symposium on Aero Aqua Bio-Mechanisms 2009年

  69. 蚊の吸血ポンプ特性評価 査読有り

    菊地謙次, 寺田信幸, 望月修

    生体医工学 46 (2) 232-237 2008年

    DOI: 10.11239/jsmbe.46.232  

  70. Micro-PIV Measurements in Micro-Tubes and Proboscis of Mosquito 査読有り

    Kenji KIKUCHI, Osamu MOCHIZUKI

    Journal of Fluid Science and Technology 3 (8) 957-986 2008年

    出版者・発行元:The Japan Society of Mechanical Engineers

    DOI: 10.1299/jfst.3.975  

    ISSN:1880-5558

    詳細を見る 詳細を閉じる

    Effects of the relative size of a particle to the diameter of a micro-tube on velocity profiles obtained by the micro-PIV measurement of the flow through the micro-tube were investigated to achieve the accuracy of measurements of the flow in a proboscis of a mosquito. The velocity profiles obtained for different diameter-ratios of a fluorescent particle and fused silica micro-tube were compared with the exact solution of the velocity profile of flow through a circular pipe at a low Reynolds number. A suitable diameter-ratio was found to be less than 0.04. The velocity profile of flow through the proboscis of a mosquito measured by using the suitable micro-PIV method satisfying the above condition was found to be different from the exact solution of the circular-pipe flow near the center of the proboscis. The velocity profile in the proboscis was similar to that of a rectangular cross section which was verified by a SEM observation.

  71. Inside Flow of Mosquito's Proboscis

    Kenji Kikuchi, Osamu Mochizuki

    DFD06 Meeting of The American Physical Society 2006年

  72. Pump system of Mosquito

    Kenji KIKUCHI, Nobuyuki TERADA, Osamu MOCHIZUKI

    The 3rd International Symposium on Aero Aqua Bio-Mechanisms 2006年

  73. Mosquito’s sucking mechanism

    Kenji Kikuchi, Osamu Mochizuki

    DFD05 Meeting of The American Physical Society 2005年

  74. Mosquito’s Sucking Blood Mechanism

    Kenji KIKUCHI, Osamu MOCHIZUKI

    The 4th KSME-JSME Thermal and Fluids Engineering Conference 24 (1) 133-134 2005年

    出版者・発行元:The Visualization Society of Japan

    DOI: 10.3154/jvs.24.Supplement1_133  

    ISSN:0916-4731

    詳細を見る 詳細を閉じる

    The purpose of our study is to apply Mosquito's sucking blood mechanism to a pump of μ-TAS for checking blood. We want to know how high the power of Mosquitos pump is have. This paper presents a structure of Mosquitos bio-pump, and its characteristics as mechanical pump. We made the mosquito feed blood of an arm. Pictures are taken by SEM, and many slices of a mosquito with 2μm thickness after fixed by wax were made. We anatomized the mosquito's head and picked up the bio-pump under the microscope. The mosquitos bio-pump is found to be enough power to apply a pump of μ-TAS.

  75. Mosquito's proboscis 査読有り

    K Kikuchi, O Mochizuki

    JOURNAL OF VISUALIZATION 8 (1) 7-7 2005年

    出版者・発行元:IOS PRESS

    DOI: 10.1007/BF03181596  

    ISSN:1343-8875

  76. Performance of mosquito’s pump

    Kenji Kikuchi, Osamu Mochizuki

    DFD04 Meeting of The American Physical Society 2004年

︎全件表示 ︎最初の5件までを表示

MISC 54

  1. 歯科治療における飛沫エアロゾルの可視化 招待有り

    渡辺隼, 菊地謙次, 小林洋子, 矢代航, 金髙弘恭, 江草宏

    光アライアンス 34 (8) 35-39 2023年8月

  2. 歯科治療で発生するエアロゾル挙動の可視化

    小林 洋子, 渡辺 隼, 梶田 倫功, 山内 健介, 金高 弘恭, 江草 宏, 五十嵐 薫, 矢代 航, 菊地 謙次, 西村 秀一, 森島 浩允, 佐藤 舜, 菅井 優生

    東北大学歯学雑誌 39/40/41 (2/1-2/1) 49-49 2022年6月

    出版者・発行元:東北大学歯学会

    ISSN:0287-3915

  3. ジオラマ環境における酵母発酵流れの力学的理解 ~微生物由来ブラジルナッツ効果の発見~ 招待有り

    菊地謙次, 石川拓司

    アグリバイオ 50 1154-1158 2021年11月

  4. 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年11月

    出版者・発行元:(株)ニュー・サイエンス社

    ISSN:1346-7557

    詳細を見る 詳細を閉じる

    生体における生理的現象は、細胞スケールでの熱的ゆらぎや生化学的反応が支配的なシステムから、組織・臓器スケールでの流動拡散現象が支配的なシステムまで幅広い物理スケールで恒常的に行われている。生体外においては、個体と外界(周囲流体:空気や水など)との干渉は、巨視的な確率論(個体の遭遇確率や数密度)や周囲の構造的制約、周囲流動場により変化し、数理的また工学的に理解されうることが多い。本稿では、モデル生物を用いた生体流動の医学的・生物学的機能を推し量る方法論として、これまでに筆者らが工学的手法を用いて解析してきた研究の概略を解説したい。医学的知見として、ゼブラフィッシュ稚魚を用いた「食後の消化器蠕動運動の変化と腸内における輸送と撹拌」の研究と、ブタ皮膚を用いた「皮膚上皮への機械的摩擦刺激によって生ずる皮膚の物質透過脆弱化」の研究を紹介する。また、生物学的知見として、線虫C.elegansを用いた「餌捕食量と生存率」の研究と、酵母を用いた「生物誘起流れの細胞増殖への自己還元」の研究を紹介する。(著者抄録)

  5. 知って得する最新情報 マスクや衣服の擦れによる皮膚の脆弱化 皮膚のバイオメカニクスと摩擦刺激によるひずみの積み残し

    菊地 謙次

    皮膚病診療 43 (3) 268-269 2021年3月

    出版者・発行元:(株)協和企画

    ISSN:0387-7531

  6. 知って得する最新情報 マスクや衣服の擦れによる皮膚の脆弱化 摩擦刺激と角化細胞の塑性変形

    菊地 謙次

    皮膚病診療 43 (2) 172-173 2021年2月

    出版者・発行元:(株)協和企画

    ISSN:0387-7531

  7. Drug Permeation Measurement through the Skin by using a Two-Photon Laser Induced Fluorescent Microscopy 査読有り

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

    8th International Conference on Fluid Mechanics (ICFM8) S10BM0-04 2018年9月

  8. Behavior of motile unicellular alga flowing in a microchannel 査読有り

    Cheng-Hsi Chuang, Kenji Kikuchi, Azusa Kage, Takuji Ishikawa

    8th International Conference on Fluid Mechanics (ICFM8) S10BM0-01 2018年9月

  9. Gut Bacterial Flow in Zebrafish Larva

    Masahiro Takahashi, Kenji Kikuchi, Keiko Numayama-Tsuruta, Takuji Ishikawa

    The Seven International Symposium on Aero Aqua Bio-mechanisms ISABMEC 2018 26 2018年8月

  10. 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年6月

  11. 197 コラーゲンゲル上に培養したがん細胞挙動の計測

    岩崎 悠和, 今井 陽介, 菊地 謙次, 沼山 恵子, 重田 峻輔, 石川 拓司

    東北支部総会・講演会 講演論文集 2016 (0) 191-192 2016年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmeth.2016.51.191  

  12. 201 ゼブラフィッシュの腸内の蠕動運動のリアルタイム可視化

    ノ ヒョンタク, 菊地 謙次, 沼山 恵子, 石川 拓司

    東北支部総会・講演会 講演論文集 2016 (0) 199-200 2016年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmeth.2016.51.199  

  13. PS8-13 Effect of mucous viscosity on ciliary beat in the tracheal lumen(PS8: Poster Short Presentation VIII,Poster Session)

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

    Proceedings of the ... Asian Pacific Conference on Biomechanics : emerging science and technology in biomechanics 2015 (8) 364-364 2015年9月16日

    出版者・発行元:一般社団法人日本機械学会

  14. 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年9月16日

    出版者・発行元:一般社団法人日本機械学会

  15. 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年9月16日

    出版者・発行元:一般社団法人日本機械学会

  16. W052002 蚊の吸血機構に学ぶ血球との干渉低減について

    菊地 謙次

    年次大会 : Mechanical Engineering Congress, Japan 2015 "W052002-1"-"W052002-2" 2015年9月13日

    出版者・発行元:一般社団法人日本機械学会

    詳細を見る 詳細を閉じる

    We have been focusing on a possibility of low interference within blood flow in a micro scale channel. The RBC is at once taken heavy shear stress from velocity fields, the hemolysis, which put inside hemoglobin out, occurs. In that case, the RBC is broken by shear stress and makes to change to ghost RBC. Such blood isn't suitable for blood checking of healthcare hence we have to suck blood under pressure loss restriction. The final goal of this research is an inspired design for micro needle learned by mosquito blood sucking mechanism. We perform that a consideration of low RBC interference in micro channel learned by mosquito blood sucking mechanism by an analytical method of basic fluid mechanics.

  17. クラミドモナスの鞭毛は上向きトルク発生に寄与する 招待有り

    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年4月

    出版者・発行元:京都大学

    ISSN:1880-2818

  18. 2B35 クラミドモナスの分布に及ぼすエアレーションの影響(OS1-2:自然界のバイオメカニクス・バイオミメティクス(2))

    野中 佑樹, 菊地 謙次, 沼山 恵子, 鹿毛 あずさ, 上野 裕則, 石川 拓司

    バイオエンジニアリング講演会講演論文集 2015 (0) 371-372 2015年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2015.27.371  

  19. 2B41 気道上皮の繊毛運動と流れに及ぼす粘液粘度の影響(OS1-3:自然界のバイオメカニクス・バイオミメティクス(3))

    垪和 智文, 菊地 謙次, 上野 裕則, 沼山 恵子, 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 2015 (0) 373-374 2015年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebio.2015.27.373  

  20. 1316 気道繊毛上の流れ

    垪和 智文, 菊地 謙次, 上野 裕則, 沼山 恵子, 山口 隆美, 石川 拓司

    流体工学部門講演会講演論文集 2015 (0) _1316-1_-_1316-2_ 2015年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmefed.2015._1316-1_  

    ISSN:1348-0251

    詳細を見る 詳細を閉じる

    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.

  21. J0260202 微小流路内における赤血球の拡散現象の計測

    チェンシー チャン, 菊地 謙次, 沼山 恵子, 山口 隆美, 石川 拓司

    年次大会 2015 (0) _J0260202--_J0260202- 2015年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmemecj.2015._J0260202-  

    詳細を見る 詳細を閉じる

    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.

  22. A104 せん断流れ中のツリガネムシの振る舞い(A1-1 生体計測1)

    吉田 尚人, 菊地 謙次, 鹿毛 あずさ, 沼山 恵子, 永井 萌土, 石川 拓司

    バイオフロンティア講演会講演論文集 2015 (0) 7-8 2015年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebiofro.2015.26.7  

    ISSN:1348-2939

  23. A108 二光子顕微鏡を用いた皮膚内薬物濃度の計測(A1-2 生体計測2)

    重田 峻輔, 菊地 謙次, 沼山 恵子, 石川 拓司

    バイオフロンティア講演会講演論文集 2015 (0) 15-16 2015年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmebiofro.2015.26.15  

    ISSN:1348-2939

  24. S0510103 尾ひれまわりの流れ([S051-01]噴流,後流およびはく離流れ現象の探求と先端的応用(1),流体工学部門)

    上原 裕介, 菊地 謙次, 窪田 佳寛, 望月 修

    年次大会 : Mechanical Engineering Congress, Japan 2014 (0) "S0510103-1"-"S0510103-4" 2014年9月7日

    出版者・発行元:一般社団法人日本機械学会

    詳細を見る 詳細を閉じる

    There are various shapes in the tail fin of fish in nature. The way to use of tail fin should differ by shapes. In this study, we aimed to determine the relationship between thrust generation and fish fin shape. To compare the effect of fin shape had on thrust generation, we categorized the morphological shapes of fish fins into equilateral polygonal shapes. Polygonal fins were used to generate thrust that depended only on shape. These fins were constructed of a hard elastic material to eliminate any influence of shape deformation. A servomotor with a reciprocal rotation moved a fin cyclically, and thrust was experimentally measured using a strain gage system. We experimented in static fluid and uniform flow. In static fluid, thrust tended to be proportional to the inertia moment of a fin, which indicated difficulty with rotation. Moreover, this trend for thrust generation was directly related to the length of the perimeter of a polygonal fin. In uniform flow, thrust is reduced relative to the static fluid. Highest thrust was generated by the diamond shape.

  25. 尾ひれまわりの流れ

    上原裕介, 菊地謙次, 窪田佳寛, 望月修

    日本機械学会年次大会講演論文集(CD-ROM) 2014 ROMBUNNO.S0510103 2014年9月6日

    ISSN:2424-2667

  26. 浸透流の蛇行について

    豊田睦, 菊地謙次, 窪田佳寛, 望月修

    可視化情報学会誌 34 (Suppl.1) 163‐164 2014年7月1日

    ISSN:0916-4731

  27. 2G35 葉脈内における水の流れ(OS1-1:自然界のバイオメカニクス・バイオミメティクス(1))

    菊地 謙次, 佐藤 慧拓, 望月 修

    バイオエンジニアリング講演会講演論文集 2014 (26) 541-542 2014年1月10日

    出版者・発行元:一般社団法人日本機械学会

  28. J0220101 微細藻類の分布に及ぼすエアレーションの影響([J022-01]生物規範メカニクス・システム:生物の運動、力学及びミメティクスセッション(1))

    野中 佑樹, 上野 裕則, 沼山 恵子, 菊地 謙次, 石川 拓司

    年次大会 2014 (0) _J0220101--_J0220101- 2014年

    出版者・発行元:一般社団法人 日本機械学会

    DOI: 10.1299/jsmemecj.2014._J0220101-  

    詳細を見る 詳細を閉じる

    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.

  29. J027024 葉脈における流れ([J027-02]生物規範メカニクス・システム:生物の運動,力学及びミメティクス(2))

    佐藤 慧拓, 菊地 謙次, 望月 修

    年次大会 : Mechanical Engineering Congress, Japan 2013 "J027024-1"-"J027024-2" 2013年9月8日

    出版者・発行元:一般社団法人日本機械学会

    詳細を見る 詳細を閉じる

    The Leaf has a complex network as leaf vein. The leaf vein supply water efficiently to the whole of own. If there is some worm hole on its leaf by bug biting, the water in leaf vein flows continuously. This network system might be applied bio-mimically for an electrical and water infrastructure in near future. We observed the flow patterns of water in the Nandina domestica's Leaf vein with three patterns of normal leaf, damaged leaf and only leaf vein. The flow in leaf vein ware visualized by fluorescent solution by own water suction of leaf. As a result, the most of sucked water was flowed in the main leaf vein in each leaves, then the flows were spread into the lateral veins gradually. In the case of damaged leaf, the flow in the main leaf vein stopped at the worm hole, the water was bypassing the hole through the other fine veins. We found that leaf veins supply the water to whole of leaf even if leaf has damage in leaf vein according as a capillary phenomenon.

  30. 魚の尾鰭形状と推進力に関する研究

    上原裕介, 菊地謙次, 窪田佳寛, 望月修

    バイオエンジニアリング講演会講演論文集 25th (25) 123-124 2013年1月8日

    出版者・発行元:一般社団法人日本機械学会

    ISSN:1348-2920

  31. 0701 蛙の跳び込みに伴うスプラッシュの形成(OS7 生物・生体に閧する流れ,オーガナイズドセッション)

    窪田 佳寛, 菊地 謙次, 望月 修

    流体工学部門講演会講演論文集 2012 (0) 277-278 2012年11月16日

    出版者・発行元:一般社団法人日本機械学会

    ISSN:1348-0251

    詳細を見る 詳細を閉じる

    The objective of this study is to understand the formation of water splash by the frog diving into water.Splash formation by the frog diving was investigated by using high speed camera.The characteristics of frog diving were studied with model experiments.The model experiments obtained the influence of both body shape and hydrophihcity as surface condition.Body shape was investigated with the influence of tail shape of body and NACA 0012 airfoil in cross-section.Frog diving caused the small water splash formation with air cavity under the water.The formation of splash was related to the film-flow caused by body impacted to water surface.The fore limb of frog set along the body during the dive.This is the reason to inhibit the formation of separation of film-flow.The strong hydrophihc body of frog was caused film separation.

  32. 蝶の滑空特性

    北島綾香, 窪田佳寛, 菊地謙次, 望月修

    可視化情報学会誌 32 (Suppl.2) 125‐126 2012年9月15日

    ISSN:0916-4731

  33. 生体を模擬したハイドロゲル壁面近傍における流れの数値シミュレーション

    横山真男, 菊地謙次, 窪田佳寛, 望月修

    可視化情報学会誌 32 (Suppl.2) 133‐134 2012年9月15日

    ISSN:0916-4731

  34. 加速する三次元物体の抵抗係数

    今野友博, 菊地謙次, 市川誠司, 窪田佳寛, 望月修

    日本機械学会年次大会講演論文集(CD-ROM) 2012 ROMBUNNO.S053046 2012年9月8日

    ISSN:2424-2667

  35. 魚の尾鰭形状と推進力に関する研究

    工藤裕司, 菊地謙次, 窪田佳寛, 望月修

    バイオエンジニアリング講演会講演論文集 24th (CD-ROM) (24) ROMBUNNO.8G36-1"-"8G36-2" 2012年1月6日

    出版者・発行元:一般社団法人日本機械学会

    ISSN:1348-2920

  36. 直列円錐群まわりの流れの可視化

    四元大, 菊地謙次, 窪田佳寛, 望月修

    バイオエンジニアリング講演会講演論文集 24th (CD-ROM) (24) ROMBUNNO.8G37-1"-"8G37-2" 2012年1月6日

    出版者・発行元:一般社団法人日本機械学会

    ISSN:1348-2920

  37. 蛙の跳び込みに伴うスプラッシュの形成

    窪田佳寛, 菊地謙次, 望月修

    日本機械学会流体工学部門講演会講演論文集(CD-ROM) 90th ROMBUNNO.0701 2012年

    ISSN:1348-2882

  38. 第39回可視化情報シンポジウムに参加して

    菊地 謙次

    可視化情報学会誌 = Journal of the Visualization Society of Japan 31 (123) 163-163 2011年10月1日

    ISSN:0916-4731

  39. 濃度差によってスポンジを透過する流れについて

    豊田睦, 菊地謙次, 窪田佳寛, 望月修

    可視化情報学会誌 31 (Suppl.2) 103-104 2011年9月13日

    ISSN:0916-4731

  40. カエルの行動の可視化

    田口綾乃, 窪田佳寛, 菊地謙次, 望月修

    可視化情報学会誌 31 (Suppl.2) 101-102 2011年9月13日

    ISSN:0916-4731

  41. 加速する三次元物体の抵抗係数

    菊地謙次, 今野友博, 市川誠司, 窪田佳寛, 望月修

    日本機械学会年次大会講演論文集 2011 (CD-ROM) ROMBUNNO.S054021 2011年9月10日

    ISSN:2424-2667

  42. 1106 生体表面近傍の流れ(OS11-2 生物・生体に関する流れ,オーガナイズドセッション)

    稲葉 利彦, 市川 誠司, 菊地 謙次, 望月 修

    流体工学部門講演会講演論文集 2010 317-318 2010年10月29日

    出版者・発行元:一般社団法人日本機械学会

    ISSN:1348-2882

    詳細を見る 詳細を閉じる

    It aims to establish a method of measuring friction drag of bio-material under unsteady moving condition by using a motion capture system. The model covered with several materials was fallen in a water tank by gravity, and measured each speed by using a high speed video camera. We carried out the estimation of friction drag of the bio-material surface by an unsteady motion equation. In this study, the materials we evaluated were a hydrophobic cloth, artificial skins and a sea snake skin. As a result, the hairless artificial skin showed the smallest drag-coefficient and the hydrophobic cloth the largest.

  43. 1105 植物細胞の原形質流動について(OS11-1 生物・生体に関する流れ,オーガナイズドセッション)

    住田 陽亮, 市川 誠司, 菊地 謙次, 望月 修

    流体工学部門講演会講演論文集 2010 315-316 2010年10月29日

    出版者・発行元:一般社団法人日本機械学会

    ISSN:1348-2882

    詳細を見る 詳細を閉じる

    Protoplasmic streaming is a phenomenon of particle movement in living cell. The particles were contained the cellular organelles and other particles called mitochondria and chloroplasts. We want to know the role of protoplasmic streaming in living plant cell. In this study we observed two types of protoplasmic streaming of Nitella and Tradescantia. The vesicle of moving speed and size were measured by microscopic observation. The cell division time was estimated from the volume of vesicle and cell, the moving speed and distribution of vesicles. As a result, the tradescantia cell division time was about 3.47×10^<17> hours. It was found that the protoplasmic streaming of Tradescantia was contributed 1.64×10^<-15>% for cell volume expansion

  44. 1129 小生物の遊泳時に見られる渦について(OS16:生物流体のバイオミメティクス)

    市川 誠司, 菊地 謙次, 望月 修

    バイオエンジニアリング講演会講演論文集 2009 (22) 387-387 2010年1月8日

    出版者・発行元:一般社団法人日本機械学会

  45. カエル皮膚表面上の流れ(生物の流れ(2),一般講演)

    菊地 謙次, 稲葉 利彦, 市川 誠司, 望月 修

    日本流体力学会年会講演論文集 2010 232-232 2010年

    出版者・発行元:日本流体力学会

    詳細を見る 詳細を閉じる

    A detail measurement of velocity gradient on wall surface is to better understand a friction drag against wall. We carried out the visualization of flow near the wall surface by confocal micro PIV system. In generally known, a surface of a living tissue has reduction of friction drag because of a tissue consisted of a hydro-gel. To know the effect of friction drag by surface materials, we developed the confocal micro PIV system for measurement of velocity gradient near the surface. It was found that the velocity profile of dropped flow on glass surface was similar to that of open channel flow. This system is suitable for measurement of friction drag effected on wall with free surface flow.

  46. 1608 微生物(ボウフラ)周りの流れ(OS16-3 生物・生体工学に関する流れ,オーガナイズドセッション)

    菊地 謙次, 望月 修

    流体工学部門講演会講演論文集 2009 497-498 2009年11月6日

    出版者・発行元:一般社団法人日本機械学会

    ISSN:1348-2882

    詳細を見る 詳細を閉じる

    The purpose of our study is to analyze swimming motion of a mosquito larva. When it meets some dangerous situations, it escapes actively from air-water surface to bottom with rapid swimming motion and some time later it is back to water surface for its breathing. A swimming thrust is obtained by a paddling motion of its tail fin with a separation of a vortex in the power stroke. We measured velocity vector fields around the body and wake by micro PIV measurements. It was found that a snapping motion of its tail fin yielded thrust.

  47. ビーズ間に保持される水

    長谷川 真知子, 菊地 謙次, 望月 修

    可視化情報学会誌. Suppl. = Journal of the Visualization Society of Japan 29 (2) 259-260 2009年10月15日

    ISSN:0916-4731

  48. 蚊の吸血針内部の速度分布測定

    菊地 謙次, 望月 修

    可視化情報学会誌. Suppl. = Journal of the Visualization Society of Japan 29 (2) 239-240 2009年10月15日

    ISSN:0916-4731

  49. 強制振動を受ける微小容器内の油膜流れ

    宇山 遼一, 横山 真男, 菊地 謙次, 望月 修

    可視化情報学会誌. Suppl. = Journal of the Visualization Society of Japan 29 (2) 199-200 2009年10月15日

    ISSN:0916-4731

  50. M4-4 回転磁場を用いたマイクロロータリーポンプの開発(M4 ポンプ,液滴・気泡駆動)

    菊地 謙次, 望月 修

    マイクロ・ナノ工学シンポジウム 2009 (1) 77-78 2009年10月15日

    出版者・発行元:一般社団法人日本機械学会

    詳細を見る 詳細を閉じる

    A micro pump has not been developed for a micro TAS to transport blood because of size effects. We have developed a micro rotary pump worked by a rotary magnetic field. The rotor was designed by morphology based on mimetics of a shape of mosquito's sucking blood pump system with high performance. This pump consists of a rotor implanted magnets, a square-shaped casing and four input-output ports. We measured pressure and flow rate of the scale-up model of the micro rotary pump and compared them with numerically estimated values.

  51. 生体表面を模擬したハイドロゲル上の流れ(解析・予測・制御 流れの制御(2),一般講演)

    菊地 謙次, 市川 誠司, 望月 修

    日本流体力学会年会講演論文集 2009 356-356 2009年

    出版者・発行元:日本流体力学会

    詳細を見る 詳細を閉じる

    The purpose of our study is to know the interaction between a flow and a surface of hydro gel. Tissue of living organ like blood vessel, cartilage and eyeball is a hydro gel. It contains water, so that the surface of hydro gel is considered to be water. Thus, it is a hydrophilic material. We expect it to show good reduction of friction if we use it the wall of a conduit. To check the concept, we measured velocity profile of a film flow on the hydro gel by a micro PIV method, estimating wall share stress from the velocity gradient at the wall. We confirmed slip-velocity depending on degree of swelling of hydro gel.

  52. 蚊の頭部組織の可視化

    菊地 謙次, 望月 修

    可視化情報学会誌. Suppl. 28 (1) 329-330 2008年7月1日

    ISSN:0916-4731

  53. AM06-28-001 蚊の吸血針内流れ(生物流体・生体流体(1),一般講演)

    菊地 謙次, 寺田 信幸, 望月 修

    日本流体力学会年会講演論文集 2006 376-376 2006年

    出版者・発行元:日本流体力学会

    詳細を見る 詳細を閉じる

    The purpose of our study is to apply mosquito's pump system to μ-TAS. To drive the μ-TAS, it is important to know necessary power of the pump. The mosquito's pump has surely excellent mechanism that we never know by our previous estimation. We focused on how high the power of mosquito's pump is and how small the resistance in a proboscis is. To know the sucking mechanism of mosquito, we measured the Blood flow by Mosquito's sucking by using micro-PIV measurements directly. Furthermore, to know the precise velocity distribution in Mosquito's proboscis, we used a confocal micro-PIV system. As result, we could obtain that there are a possibility of drag reductive effect at the interactions between flow and wall. In this paper, we suggested that Mosquito's pump system has the possibilities to apply a μ-TAS devise by the microscopic observation of a micro flow.

  54. 可視化シンポジウムに参加して

    菊地 謙次

    可視化情報学会誌 = Journal of the Visualization Society of Japan 24 (95) 260-260 2004年10月1日

    ISSN:0916-4731

︎全件表示 ︎最初の5件までを表示

書籍等出版物 1

  1. Integrated Nano-Biomechanics 1st Edition

    菊地 謙次

    Elsevier 2018年1月

講演・口頭発表等 23

  1. 流れ知り、生き物を知る~微生物からヒトにおける生物流体力学~ 招待有り

    菊地謙次

    第36回生命科学交流ミーティング 2023年2月

  2. Macro biological transports induced by micro-scale gas generation by fermenting yeast cells 招待有り

    Kikuchi Kenji

    33rd 2022 International Symposium on Micro-NanoMechatronics and Human Science 2022年11月

  3. 生体流動のライブイメージングとバイオメカニクス~微生物からヒトにおける生物流体力学~ 招待有り

    菊地謙次

    浅虫教育研究センター令和4年度 公開臨海実習(Aコース)異分野融合特別講義 2022年8月

  4. Microbial mixing and transport by yeast fermeting yeast

    Kenji Kikuchi, Atul Srivastava, Takuji Ishikawa

    Biological Fluids & Flows: A Conference to celebrate the 80th Birthday of Prof. Tim Pedley FRS 2022年3月31日

  5. 皮膚伸展刺激による経皮吸収促進効果と薬剤表面特性の関係性

    安田廉平, 石川拓司, 菊地謙次

    2022年1月13日

  6. 経皮的インターベンションにおける穿刺抵抗力低減を目指した振動針の開発

    杉山航二郎, 菊地謙次, 高瀬圭, 石川拓司

    第32回バイオフロンティア講演会, 講演論文集 医療機器・診断・治療4 2D28 (2022) 2022年1月13日

  7. Instantaneous puncture for accurate needle insertion in percutaneous intervention

    Kojiro Sugiyama, Kenji Kikuchi, Tomomi Sato, Sota Oguro, Satoru Yanagaki, Kei Takase, Takui Ishikawa

    The 11th Asian-Pacific Conference on Biomechanics 2021年12月3日

  8. 病原菌・ウイルスが皮膚を介して 感染するリスクに警鐘

    菊地謙次

    CSJ化学フェスタ 「コロナに負けるな!衛生分野からの挑戦」 2021年10月

  9. なぜ上面発酵ビール酵母は培養液中に浮遊できるのか? 招待有り

    菊地謙次

    日本機械学会第33回バイオエンジニアリング部門講演会 2021年6月

  10. 繊毛・鞭毛運動が織りなす生物流動,計測自動制御学会分子ロボティクス研究会 招待有り

    菊地謙次

    計測自動制御学会分子ロボティクス研究会 2020年10月

  11. バイオイメージングが拓く生物流体工学 招待有り

    菊地謙次

    日本機械学会東北支部第56期秋季講演会 2020年9月

  12. ゼブラフィッシュ稚魚を用いた腸蠕動による撹拌と輸送 招待有り

    菊地謙次

    せん断流の多様な機能の探究と先端科学技術への応用に関する研究分科会 2020年7月

  13. 生物流体から学ぶバイオミメティクス 招待有り

    菊地謙次

    2019 年度高分子・ハイブリッド材料研究センター(PHyM)若手フォーラム 2019年11月13日

  14. Phase contrast x-ray imaging in bio-mechanical aspects; mosquito bloody ingestion 国際会議 招待有り

    Kenji Kikuchi

    Next Generation Synchrotron Radiation Workshop 2019年8月18日

  15. 蚊の吸血ポンプの隠されたロバスト性 招待有り

    菊地謙次

    2018年度 研究集会 「生物流体力学の展望」 2018年11月12日

  16. 生体流動の可視化と生体ポンプの特性評価 招待有り

    菊地謙次

    第38回エアロ・アクアバイオメカニズム学会 2018年3月20日

  17. 生物における流れの可視化とバイオイメージング 招待有り

    菊地謙次

    フロンティアバイオイメージング研究会 2017年11月7日

  18. Visualization of Biological flow in small nature 国際会議 招待有り

    Kenji Kikuchi

    Fluid & Aerodynamics Research Group Seminar Series 2017年3月1日

  19. 生物における流れと運動 招待有り

    菊地謙次

    自動車技術会 流体技術部門委員会 2016年2月12日

  20. 蚊の吸血に学ぶ血球との干渉低減について 招待有り

    菊地謙次

    日本機械学会年次大会ワークショップ「血流を視る研究会」 2015年9月16日

  21. 自然界の忍者!血を吸う蚊のひみつ 招待有り

    菊地謙次

    第21回流れのふしぎ展 2015年8月11日

  22. 生物流れの可視化で未来を切り拓く!?バイオミメティクスとシンバイオシスへの展望? 招待有り

    菊地謙次

    可視化情報シンポジウム 2015年7月21日

  23. 蚊の吸血機能の解明と可視化 招待有り

    菊地謙次

    日本混相流学会・日本実験力学会合同研究会 2012年8月8日

︎全件表示 ︎最初の5件までを表示

産業財産権 5

  1. 鮮度計測装置及び鮮度計測方法

    菊地謙次, 望月修, 東洋, 杉田杏奈

    特許第6463906号

    産業財産権の種類: 特許権

  2. 解凍装置及び品質維持装置

    加藤正平, 菊地謙次, 畠一嘉(ヒガノ株式会社, 大川令, 東洋

    産業財産権の種類: 特許権

  3. Vibrating needle deveice and needle insertion method

    Kenji Kikuchi, Kojiro Sugiyama, Takuji Ishikawa, Kei Takase

    産業財産権の種類: 特許権

  4. 振動針装置及び針の挿入方法 (PCT国際出願)

    菊地謙次, 杉山航二郎, 石川拓司, 高瀬圭

    産業財産権の種類: 特許権

  5. 流体抵抗計測方法及びその装置

    鳴尾丈司, 津濃株式会社主任研究員, 荻野毅(美津濃株式会社主任研究員, 田中啓介, 濃株式会社主任研究員, 松崎健(美津濃株式会社アパレル開発生産部, 菊地謙次, 望月修, 東洋

    特許第5841631号

    産業財産権の種類: 特許権

共同研究・競争的資金等の研究課題 14

  1. 生体流動・濃度場非侵襲イメージング法の深化と生体内生理的免疫系干渉への展開

    菊地 謙次, 石川 拓司

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research

    研究種目:Grant-in-Aid for Scientific Research (B)

    研究機関:Tohoku University

    2022年4月1日 ~ 2026年3月31日

  2. 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

    2021年10月 ~ 2026年3月

  3. 生物系アクティブマターの予測 と制御を目指した移動現象論の 構築

    2021年10月 ~ 2026年3月

  4. ジオラマ環境における濃密微生物のin vivo4D-X線トモグラフィー法の開発

    2021年10月 ~ 2026年3月

  5. 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

    2021年10月7日 ~ 2025年3月31日

  6. 生物流体と生命現象のクロストークダイナミクスの創成

    2021年4月 ~ 2024年3月

  7. 振動穿刺システムによるIVRアブレーション治療の精度向上に関する研究

    2021年4月 ~ 2023年3月

  8. 微生物バイオメカニクスの深化

    石川 拓司, 菊地 謙次, 大森 俊宏, 今井 陽介, 鹿毛 あずさ

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research

    研究種目:Grant-in-Aid for Scientific Research (A)

    研究機関:Tohoku University

    2017年4月1日 ~ 2021年3月31日

    詳細を見る 詳細を閉じる

    本年度は、主に分子スケールと細胞スケール、メゾスケール、マクロスケールの研究課題を推進し、応用研究へと展開した。主要な研究実績は以下の通りである。 1.せん断流れ条件下において、細胞膜や赤血球膜を模擬したベシクル膜上の膜タンパク挙動をDPD手法により調べ、移流と拡散による膜タンパクの輸送現象を明らかにした(Nakamura, et al., Biophys. J. 2019) 2.繊毛の協調運動を表現できる微生物の数理モデル化に世界で初めて成功し、微生物遊泳中においては繊毛層のエネルギ損失が極めて高いことを発見した(Ito, et al., J. Fluid Mech., 2019) 3.微細藻類が走地性を示すメカニズムを調べ、従来言われたbottom-heavinessの効果よりも、形の非対称性の効果が重要であることを解明した(Kage, et al., J. Exp. Biol., 2020) 4.微細藻類のGoniumの走光性現象に対する実験と理論、数値シミュレーションを実施し、走光性を示すメカニズムを解明した(Maleprade, et al., Phys. Rev. E, 2020) 5.線虫がバクテリアを捕食するメカニズムを調べ、線虫のフィルターの微細構造と摂食メカニズム、および摂食機能を解明した(Suzuki, et al., Theor. Appl. Mech. Lett., 2019) 6.生体内の3次元的な物質輸送を、顕微鏡下で高時間解像度で計測する手法を開発した(Kikuchi, et al., PLoS ONE, 2019)

  9. in vivo経皮吸収計測法の開発と塗込による浸透促進効果の解明

    菊地 謙次

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research

    研究種目:Grant-in-Aid for Challenging Exploratory Research

    研究機関:Tohoku University

    2016年4月1日 ~ 2018年3月31日

    詳細を見る 詳細を閉じる

    経皮吸収薬の薬剤浸透量を能動的に制御するには、皮膚内部の三次元構造と薬剤物性および皮膚表面のひずみと薬液浸透量の関係を結びつける定量的解析が必要不可欠である。本研究では、経皮吸収薬の浸透を表皮における塗込動作による能動的制御を目的とし、二光子顕微鏡を用いた革新的な非侵襲皮膚三次元構造の計測と、共焦点顕微鏡を駆使した独創的な薬剤皮膚表面のひずみおよび浸透量計測を行い経皮吸収量の能動的制御法の開発を行った。塗込動作を付加した皮膚表面のひずみと皮膚内部への薬剤浸透量を計測し、定量評価することで、塗込動作による浸透促進効果について明らかにした。

  10. in vivo経皮吸収計測法の開発と塗込による浸透促進効果の解明 競争的資金

    菊地 謙次

    2016年4月 ~ 2017年3月

    詳細を見る 詳細を閉じる

    経皮吸収薬の薬剤浸透量を能動的に制御するには,皮膚内部の三次元構造と薬剤物性および塗込せん断速度と薬液浸透量の関係を結びつける定量的解析が必要不可欠である.本研究では,経皮吸収薬の浸透を表皮における塗込動作による能動的制御を目的とし,二光子顕微鏡を用いた革新的な非侵襲皮膚三次元構造の計測と,共焦点顕微鏡を駆使した独創的な薬剤せん断速度計測および浸透量計測を行い経皮吸収量の能動的制御法の開発を目的としている. 本年度は, 1)二光子顕微鏡を用いて,in vivoにおけるブタ皮膚の三次元組織構造の計測手法の構築を行なった.生体毒性がほとんどない蛍光分子ウラニンを薬剤モデルとし,薬剤モデルが皮膚内部根浸透した後に,二光子顕微鏡で皮膚内部を観察することで薬剤浸透経路の観察に成功した.また,皮膚表面の角質層をローダミンBにより可視化することで,薬剤と皮膚との境界となるミクロスケールの構造の計測に成功した.また,選択的組織染色により皮膚内部における乳頭層の配向構造を細胞核の分布とその局在を可視化することに成功し,薬剤浸透と皮膚内部の詳細な構造の計測を行なった. 2)共焦点顕微鏡を用いて,皮膚表面に付した薬剤の経皮吸収量の計測法の構築を行なった.皮膚に付した薬剤モデル内の蛍光輝度の時間的変化について,高速共焦点スキャナーを使用して計測することで,これまで我々が提案してきた共焦点顕微鏡による傾斜観察法を発展的に応用し,観察面を傾斜させ奥行き方向の浸透を同時刻に計測する手法を開発し,薬剤濃度の時間変化から皮膚内部へと浸透する経皮吸収薬剤量のリアルタイム計測に成功した.また,皮膚にせん断付加を作用させる機械的摺動装置の設計及び開発を行った.

  11. 血流との干渉が小さい生体材料の開発研究

    菊地 謙次

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B)

    研究種目:Grant-in-Aid for Young Scientists (B)

    2013年4月1日 ~ 2015年3月31日

    詳細を見る 詳細を閉じる

    低摩擦性を持つ生体高分子表面上の壁面せん断応力を非侵襲で計測する手法として,生体表面上の流れを直接計測することでせん断力を計測・評価する手法を提案した.従来法とは異なり力学センサを必要としない新たな壁面せん断力手法を開発したことにより,様々な表面状態によってもその表面上のせん断力計測を可能とした.また,表面における壁面せん断応力は,生体高分子表面における分子鎖間隙に深く関連し,本研究期間においてその分子鎖間隙と摩擦低減率について定量的に評価した.

  12. 血流との干渉が小さい生体材料の開発研究 競争的資金

    菊地 謙次

    2013年4月 ~ 2014年3月

    詳細を見る 詳細を閉じる

    低摩擦性を持つ生体高分子表面上の壁面せん断応力を非侵襲で計測する手法として,生体表面上の流れを直接計測することでせん断力を計測・評価する手法を提案した.従来法とは異なり力学センサを必要としない新たな壁面せん断力手法を開発したことにより,様々な表面状態によってもその表面上のせん断力計測を可能とした.また,表面における壁面せん断応力は,生体高分子表面における分子鎖間隙に深く関連し,本研究期間においてその分子鎖間隙と摩擦低減率について定量的に評価した.

  13. ハイドロゲル表面および内部と周囲流体とのマイクロ干渉 競争的資金

    菊地 謙次

    提供機関:Japan Society for the Promotion of Science

    制度名:Grants-in-Aid for Scientific Research Grant-in-Aid for Research Activity Start-up

    研究種目:Grant-in-Aid for Research Activity Start-up

    研究機関:Toyo University

    2009年4月 ~ 2010年3月

    詳細を見る 詳細を閉じる

    本研究では,ハイドロゲル材料における親水性表面のごく表面における流れを,微小領域速度勾配計測法を用いて計測し,またゲル内部の水の挙動観察を行った.ゲル表面近傍ではすべり流れとなることが確認され、ゲルの含水量の増加に比例しすべり速度が増加し,反比例して壁面せん断応力が低下することが確認された.ゲル内部の水は,すべり流れに誘起され流動していることが確認され,ゲル表面の摩擦低減の可能性を見出した.

  14. μ-TAS適用超小型ポンプ開発を目的とした蚊の吸血機能の解明 競争的資金

    菊地 謙次

    2007年4月 ~ 2008年3月

    詳細を見る 詳細を閉じる

    蚊の吸血性能に関して,工学的アプローチにより実験的に調べてきた結果.(1)周期的な吸い込みと1周期中の規則的血液吸い込み速度変動.(2)蚊吸血針内における速度分布,(3)蚊頭部(ポンプを含む)の断層像,(4)吸血針内部表面組織の表面構造,(5)頭部内に備わる2連ポンプのポンプ運動周期,を計測するに至った.その成果として,蚊の吸血機構における吸い込み流量1.32×10^<-11>m^3/s,吸い込み出力は2.37×10^<-7>Wであることが明らかとなった.蚊の頭部内に二つのポンプはほぼ逆位相で運動していることが明らかとなり,これまで未解明であったポンプの運動周期を定量的に計測するに至った.蚊の吸血機構の出力は,既存の人工マイクロポンプと出力を比較すると最小のマイクロポンプと比べ約10,000分の一であるものの,容積は約1,000分の一となり寸法に対する効率は非常に高く,高効率人工ポンプと同等の効率で駆動されていることが明らかとなった.その蚊の吸血ポンプの断面形状は,拡張時にルーローの三角形の形状を成すことが明らかとなった.さらに幾何学的にルーローの三角形の膨張比を算出すると,他の多角定幅図形より大きい膨張比であることが明らかとなった.このルーローの三角形を利用したマイクロロータリーポンプの設計を行い,その模型を作り性能評価を行った.

︎全件表示 ︎最初の5件までを表示

社会貢献活動 1

  1. 日本機械学会流体工学部門流れのふしぎ展

    2013年10月1日 ~ 継続中

    詳細を見る 詳細を閉じる

    身の回りの流れに関わる現象について,科学教室,体験型展示や工作教室を通じて紹介.日本科学未来館で開催し,例年約2000人が来展.

メディア報道 10

  1. 「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

    2022年12月21日

    メディア報道種別: 新聞・雑誌

  2. 「Yeast Cells Cause Embedded Objects to Rise via The Microbial Brazil Nut Effect」

    EurekAlert, Asia Research News, AlphaGalileo, NewsBreak, Flipboard, Florida News Times他

    2022年12月8日

    メディア報道種別: インターネットメディア

  3. 「Yeast Cells Cause Embedded Objects to Rise via The Microbial Brazil Nut Effect」

    東北大学プレスリリース

    2022年12月8日

    メディア報道種別: その他

  4. 腸の活発な運動で促進される糖質吸収の可視化に成功 執筆者本人

    東北大学プレスリリース

    2022年9月22日

    メディア報道種別: その他

  5. 「Visualization of the "Brazil nut effect," an interesting phenomenon of microbial origin」

    Science Japan

    2022年2月1日

    メディア報道種別: インターネットメディア

  6. 「东北大学实现“巴西果效应”可视化,大颗粒上浮、小颗粒下沉」

    客觀日本

    2021年12月21日

    メディア報道種別: インターネットメディア

  7. 「東北大、微粒子内に沈降したプラスチックごみなどの物体が酵母の発酵時の炭酸ガスの発泡によって浮上することを発見」

    日本経済新聞

    2021年11月18日

    メディア報道種別: インターネットメディア

  8. マスクなどの摩擦刺激で皮膚が脆弱化する仕組みを解明

    東北大学プレスリリース

    2020年8月21日

  9. 蚊がゴクゴクとゴックンを飲み分ける仕組みを発見 執筆者本人

    東北大学プレスリリース

    2018年3月22日

  10. デッドエンドを回避する微生物の仕組みを発見

    東北大学プレスリリース

    2018年3月1日

    メディア報道種別: その他

︎全件表示 ︎最初の5件までを表示