'15 セミナー日程表

seminar top

市川研究室主催

Time 2016/3/4(Fri.) 16:00-18:00
Place 理学部5号館401号室 (Kyoto Univ. Science Bldg. V, Rm. 401)
Speaker Ms. Salome Mielke
Affiliation Institute of Physical Chemistry, University of Heidelberg, Germany
Title Nonlinear viscoelasticity of novel fluorocarbon materials
Abstract Novel fluorocarbon/hydrocarbon diblock amphiphiles were shown to self- assemble into hemi-micelles (d ~ 30 - 60 nm) on water [1]. Viscoelastic properties of such monolayers were investigated under periodic compression/ expansion of the monolayers [2,3]. The emergence of nonlinear response was shown, reflecting the interplay of intermolecular (long-range) and intermicellar (short-range) correlations.

[1] Krafft, M. P., Acc. Chem. Res., 2012, 45(4), 514-524.
[2] Makino, M. & Yoshikawa, K., Langmuir, 1997, 13, 7125-7134
[3] Lopez-Montero, et al., Langmuir, 2013, 29, 6634-6644.
Time 2016/3/3(Thu.) 14:00-16:00
Place 理学部5号館401号室 (Kyoto Univ. Science Bldg. V, Rm. 401)
Speaker Mr. Naoki Takeishi
Affiliation Graduate School of Biomedical Engineering, Tohoku University
Title A numerical analysis of cellular flow and adhesion in microcirculation
Abstract Cell adhesion is a multistep process consisting of margination, tethering, rolling, and stable adhesion. Each intravital event is of crucial importance in both pathological and physiological processes such as leukocyte immune function and cancer metastasis. Because this process involves not only the biochemical interaction of adhesion proteins, but also the mechanics of cell and cellular environment, the biomechanics of cell adhesion has not been fully understood yet. In this study, we developed a numerical model of cellular flow and adhesion in microcirculation. The fluid mechanics of plasma and cytoplasm was coupled with the solid mechanics of cell membrane, and the ligand-receptor interaction of adhesion proteins. All procedures were fully implemented on Graphics processing unit (GPU) to accelerate the numerical simulation. Our results suggested that the passing motion of red blood cells effectively induced leukocyte margination [1] and also CTC margination [2]. We found that the cell velocity was faster than mean blood velocity even when the leukocyte and CTC were marginated [2]. We also analyzed cell adhesion during $B!H(Bbullet motion$B!I(B in capillaries. We showed that bullet motion effectively decreased the cell velocity (in submission). This result suggests that weak ligand-receptor bindings such as PSGL-1-P-selectin, which are responsible for leukocyte rolling, allow the cell to firmly adhere to the wall in capillaries. These results will gain insight into biomechanics of cell adhesion, and will be helpful for various clinical problems, for example, diagnosing a leukocyte immune response and cancer metastasis.

[1] Takeishi N., Imai Y., Nakaaki K., Yamgacuhi T. and Ishikawa T. Leukocyte margination at arteriole shear rate. Physiol. Rep. 2:e10237, 2014.
[2] Takeishi N., Imai Y., Yamgacuhi T. and Ishikawa T. Flow of a circulating tumor cell and red blood cesss. Phys. Rev. E. 92:063011, 2015.
Time 9/10(Thu.) 10:30-12:00
Place 理学部5号館413号室 (Kyoto Univ. Science Bldg. V, Rm. 413)
Speaker1 鳥澤 嵩征氏
Affiliation1 情報通信研究機構 未来ICT研究所
Speaker2 谷口大相氏
Affiliation2 明治大学理工学部物理学科
Title Spontaneous formation and rupture of a multiscale contractile network in a microtubule-motor system
Abstract In eukaryotic cells, dynamical microtubule-based structures play key roles in mitosis, morphogenesis, and migration. Although for the formation, maintenance, and regulation of these structures, many kinds of elements are orchestrated in living cells, we demonstrated that a simple reconstituted microtubule system including only a single kind of motile crosslinker, kinesin-5, exhibited various spatiotemporal dynamics. In addition to the previously reported patterns, our system exhibited the global contraction: the network initially formed was abruptly self-ruptured while releasing elastic energy stored in the early slow contraction phase. These dynamics were controllable via the molecular biological modulation of motor properties, such as velocity or affinity to microtubules. On the basis of experiments, a coarse-grained model focusing on the contractile dynamics of networks was developed and shown to reproduce all of the experimentally observed patterns. These experimental and theoretical findings revealed the essential factors in the formation and regulation of the dynamical microtubule architectures.
Time 7/3(Fri.) 10:30-12:00
Place 理学部5号館401号室 (Kyoto Univ. Science Bldg. V, Rm. 401)
Speaker 貞包浩一朗氏
Affiliation 同志社大学 生命医科学部医情報学科
Title 光・X線・中性子散乱や光ピンセットを用いたソフトマター研究
Abstract 1) 界面不活性の働きをする界面活性剤
2) 界面活性剤水溶液や高分子ゲルのような振る舞いをする水/有機溶媒/塩の混合溶液
3) メゾ構造形成による臨界揺らぎの2次元的な振舞い
4) 光ピンセットを用いたマイクロレオロジーシステムの設計

過去のセミナー

セミナー主催研究室について

京都大学大学院 理学研究科  物理学第一教室 
市川研究室



Please contact this E-mail address, whenever you have some questions about seminars.
(semimaster@chem.scphys.kyoto-u.ac.jp)