生物现象中的力学问题参考资料电子教案全套课件.pptxVIP

中国力学学会 青年学术沙龙第三十二次活动;生物现象中的几个力学问题;;1、生物材料的缺陷非敏感尺度;1、生物材料的缺陷非敏感尺度;1、生物材料的缺陷非敏感尺度;1、生物材料的缺陷非敏感尺度;1、生物材料的缺陷非敏感尺度;;Living cells can sense mechanical forces and convert them into biological responses. Similarly, biological and biochemical signals are known to influence the abilities of cells to sense, generate and bear mechanical forces. Details of mechanical, chemical and biological interactions in cells remain elusive. ;After 24h cyclic stretch, the cells in the control cultures, left column, have no apparent preferential orientation; The 4% stretch clearly reduced the number of cells oriented in the stretch direction; This effect increased at 8% and 12% stretches.; ;Gang Bao, J. Mech. Phy. Solids, 2002, 50, 2237; Bausch et al., 1998, Biophysical Journal, 75, 2038;;;界面应力：;;;封闭解：;;Receptor–ligand binding can be affected by protein deformation. (a) A good conformational match between the receptor and ligand leads to strong binding and reaction. (b) When the receptor deforms under force, the binding affinity decreases due to poor conformational match.;A、三维模型;;;;A2）能量分析 ;;;Autumn et al., (2000, 2002)；Huber et al. (2005);Gao, et al. (2005);The toy (15 cm high; weighing 40 g) has its hand covered with the microfabricated gecko tape, which provides a 0.5 cm2 contact with the glass and a carrying capacity of 100 g.;研究背景;;研究背景;;4、壁虎、蟋蟀等昆虫的可逆黏附;;;;;;利用简单的模型讨论了生物材料的缺陷不敏感概念及相关尺度。 建立了二维广义JKR 及广义MD 模型：发现外界应变存在两个临界值将脱黏过程分为三个阶段，与细胞重新排列方向的过程非常相似，提供了解释的可能性。 建立了二维及三维广义JKR模型，分析了环境压力、温度的变化对生物分子之间黏附的影响。 建立了各向异性广义JKR模型，解释了壁虎、蚱蜢等昆虫通过黏附与脱黏的交替，实现自由运动的机理：刚度大的方向黏附强度最强，刚度小的方向黏附强度最弱。改变角度实现黏附及脱黏的交替。;致谢