arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2007.13543math.AP
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具有自噬的肿瘤生长模型:反应-(交叉)扩散系统及其自由边界极限

A tumor growth model with autophagy: the reaction-(cross-)diffusion system and its free boundary limit

Xu'an Dou, Jian-Guo Liu, Zhennan Zhou

摘要:

在本文中,我们提出了一个肿瘤生长模型,并调查自噬的空间效应。细胞分为两个阶段:正常细胞和自噬细胞,其动力学也与营养物质相耦合。首先,我们构建了一个反应-(交叉)扩散系统描述的细胞密度的演变,其中的漂移是由负梯度的联合压力,和反应项体现了独特的自噬机制。接下来,在不可压缩极限中,这样的细胞密度模型自然地连接到自由边界系统,描述肿瘤区域的几何运动。对特殊情况下的自由边界模型进行了分析,证明了细胞两相之比指数收敛到一个"良好混合"极限。在这个"良好混合"的限制下,我们得到了一个自由边界系统的解析解,它表明在自噬存在下肿瘤大小的指数增长与没有自噬的线性增长形成对比。数值模拟也提供了说明的分析性质,并探索更多的情况。

英文摘要:

In this paper, we propose a tumor growth model to incorporate and investigate the spatial effects of autophagy. The cells are classified into two phases: normal cells and autophagic cells, whose dynamics are also coupled with the nutrients. First, we construct a reaction-(cross-)diffusion system describing the evolution of cell densities, where the drift is determined by the negative gradient of the joint pressure, and the reaction terms manifest the unique mechanism of autophagy. Next, in the incompressible limit, such a cell density model naturally connects to a free boundary system, describing the geometric motion of the tumor region. Analyzing the free boundary model in a special case, we show that the ratio of the two phases of cells exponentially converges to a ``well-mixed" limit. Within this ``well-mixed" limit, we obtain an analytical solution of the free boundary system which indicates the exponential growth of the tumor size in the presence of autophagy in contrast to the linear growth without it. Numerical simulations are also provided to illustrate the analytical properties and to explore more scenarios.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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