论文标题
永久性电荷对离子流的影响：通量比的数值研究及其分叉
Permanent charge effects on ionic flow: a numerical study of flux ratios and their bifurcation
论文作者
论文摘要
离子流带有电信号，以使细胞相互通信。离子通道的永久电荷是流量特性的关键蛋白质结构，而边界条件起驱动力的作用。它们对流量性能的影响已经通过准二维泊松泊松型尼尔斯特（Nernst-Nernst-Planck）模型分析，以实现小且相对较大的永久性电荷。分析研究导致引入了反映永久电荷效应并具有普遍特性的通量比。研究还表明，通量比对大小永久性充电具有不同的行为。但是，现有的分析技术不能揭示通量比的行为，也不能揭示小型和大型永久性电荷之间的过渡。在这项工作中，我们提出了有关小额和大型永久性电荷之间桥梁的通量比的数值研究。数值结果验证了两个极端区域的分析预测。更重要的是，由于永久性电荷从小到大，因此检测到非平凡行为的出现。特别是，揭示了通量比的鞍节点分叉，通过结合分析和数值技术的能力显示了永久性电荷效应的丰富现象。数值研究中使用了自适应移动网格有限元法。
Ionic flow carries electrical signals for cells to communicate with each other. The permanent charge of an ion channel is a crucial protein structure for flow properties while boundary conditions play a role of the driving force. Their effects on flow properties have been analyzed via a quasi-one-dimensional Poisson-Nernst-Planck model for small and relatively large permanent charges. The analytical studies have led to the introduction of flux ratios that reflect permanent charge effects and have a universal property. The studies also show that the flux ratios have different behaviors for small and large permanent charges. However, the existing analytical techniques can reveal neither behaviors of flux ratios nor transitions between small and large permanent charges. In this work we present a numerical investigation on flux ratios to bridge between small and large permanent charges. Numerical results verify the analytical predictions for the two extremal regions. More significantly, emergence of non-trivial behaviors is detected as the permanent charge varies from small to large. In particular, saddle-node bifurcations of flux ratios are revealed, showing rich phenomena of permanent charge effects by the power of combining analytical and numerical techniques. An adaptive moving mesh finite element method is used in the numerical studies.
