标题： 一种能够增殖的向列相，能够集体感知各向异性基底 显示英文标题

标题： A Proliferating Nematic That Collectively Senses an Anisotropic Substrate

摘要： 受最近对生长成纤维细胞的实验启发，我们研究了在取向弹性体基底上增殖的长形细胞群中向列序的发展。 在稀疏接种后，细胞分裂并生长为局部有序但随机取向的区域，然后这些区域相互作用并与基底相互作用。 只有在临界密度以上，才能实现与基底的全局对齐，这表明了一种感知基底各向异性的集体机制。 在高密度时，系统发生堵塞，此时重新取向和增殖都会停止。 使用一个增殖向列液晶的连续模型，我们研究了生长驱动对齐和基底驱动对齐之间在控制最终堵塞状态的密度和结构方面的竞争。 我们提出，各向异性的牵引力以及细胞倾向于垂直于密度梯度方向对齐的倾向协同作用，提供了一种集体细胞对齐的机制。 显示英文摘要

摘要： Motivated by recent experiments on growing fibroblasts, we examine the development of nematic order in a colony of elongated cells proliferating on a nematic elastomer substrate. After sparse seeding, the cells divide and grow into locally ordered, but randomly oriented, domains that then interact with each other and the substrate. Global alignment with the substrate is only achieved above a critical density, suggesting a collective mechanism for the sensing of substrate anisotropy. The system jams at high density, where both reorientation and proliferation stop. Using a continuum model of a proliferating nematic liquid crystal, we examine the competition between growth-driven alignment and substrate-driven alignment in controlling the density and structure of the final jammed state. We propose that anisotropic traction forces and the tendency of cells to align perpendicular to the direction of density gradients act in concert to provide a mechanism for collective cell alignment.