Holcman D, Hoze N, Schuss Z
Ecole Normale Supérieure, Département de Mathématiques et de Biologie, 46 rue d'Ulm 75005 Paris, France.
Phys Rev E Stat Nonlin Soft Matter Phys. 2011 Aug;84(2 Pt 1):021906. doi: 10.1103/PhysRevE.84.021906. Epub 2011 Aug 5.
Particles diffusing on a membrane crowded with obstacles have to squeeze between them through funnel-shaped narrow straits. The computation of the mean passage time through the straits is a new narrow escape problem that gives rise to new, hitherto unknown, behavior that we communicate here. The motion through the straits on the coarse scale of the narrow escape time is an effective diffusion with coefficient that varies nonlinearly with the density of obstacles. We calculate the coarse-grained diffusion coefficient on a planar lattice of circular obstacles and use it to estimate the density of obstacles on a neuronal membrane and in a model of a cytoplasm crowded by identical parallel circular rods.
在布满障碍物的膜上扩散的粒子必须通过漏斗状的狭窄通道在障碍物之间挤过去。计算通过这些通道的平均通过时间是一个新的窄逃逸问题，它会产生新的、迄今未知的行为，我们在此进行阐述。在窄逃逸时间的粗粒度尺度上通过通道的运动是一种有效扩散，其系数随障碍物密度非线性变化。我们计算了圆形障碍物平面晶格上的粗粒化扩散系数，并利用它来估计神经元膜上以及由相同平行圆形杆拥挤而成的细胞质模型中的障碍物密度。
