细胞质黏度对微血管中红细胞悬浮液流动行为的影响
Effect of cytosol viscosity on the flow behavior of red blood cell suspensions in microvessels
AI总结：
本研究通过介观流体动力学模拟发现，生理高黏度比（$C\approx5$）下红细胞悬浮液的流动阻力与$C=1$时几乎相同，因为更黏稠的细胞质抑制了膜形变，形成更紧凑的细胞核和略厚的无红细胞层，从而解释了高血红蛋白浓度下流动阻力不显著增加的机制。
摘要：
微血管中血液的流动行为与组织灌注和氧气输送直接相关。当前对血液流动的建模工作主要集中在红细胞（RBCs）具有细胞质与悬浮介质之间黏度比 $C$ 为 1 的流动特性上，而在生理条件下，细胞质黏度大约是血浆黏度的五倍（即 $C\approx 5$）。$C$ 对流体流动中单个红细胞行为的重要性已被证实，但 $C$ 对血液流动的影响却鲜有研究。我们采用介观流体动力学模拟，对圆柱形微通道中不同细胞质黏度的红细胞悬浮液在各种流动条件下的流动特性进行了系统研究。我们的主要目的是将流动阻力等宏观流动特性与作为 $C$ 函数的单细胞变形及动力学联系起来。从分散的细胞构型出发，我们发现流动收敛和无红细胞层（RBC-FL）的发展仅微弱地依赖于 $C$，并且需要 $25D-50D$ 范围内的收敛长度，其中 $D$ 是通道直径。$C=5$ 时的流动阻力与 $C=1$ 时几乎相同，这是由 $C=5$ 时略厚的 RBC-FL 厚度所促成的。该效应是由于 $C=5$ 时更黏稠的细胞质抑制了膜运动和动态形状变形，导致与 $C=1$ 相比形成了更紧凑的流动细胞核。细胞质黏度对流动阻力和 RBC-FL 的微弱影响解释了为什么细胞能够拥有高浓度的血红蛋白以实现高效的氧气输送，而流动阻力却不会显著增加。
英文摘要：
The flow behavior of blood in microvessels is directly associated with tissue perfusion and oxygen delivery. Current efforts on modeling blood flow have primarily focused on the flow properties of blood with red blood cells (RBCs) having a viscosity ratio $C$ of unity between the cytosol and suspending medium, while under physiological conditions the cytosol viscosity is about five times larger than the plasma viscosity (i.e., $C\approx 5$). The importance of $C$ for the behavior of single RBCs in fluid flow has already been demonstrated, while the effect of $C$ on blood flow has only been sparsely studied. We employ mesoscopic hydrodynamic simulations to perform a systematic investigation of flow properties of RBC suspensions with different cytosol viscosities for various flow conditions in cylindrical microchannels. Our main aim is to link macroscopic flow properties such as flow resistance to single cell deformation and dynamics as a function of $C$. Starting from a dispersed cell configuration, we find that the flow convergence and the development of a RBC-free layer (RBC-FL) depend only weakly on $C$, and require a convergence length in the range of $25D-50D$, where $D$ is the channel diameter. The flow resistance for $C=5$ is nearly the same as that for $C=1$, which is facilitated by a slightly larger RBC-FL thickness for $C=5$. This effect is due to the suppression of membrane motion and dynamic shape deformations by a more viscous cytosol for $C=5$, resulting in a more compact cellular core of the flow in comparison to $C=1$. The weak effect of cytosol viscosity on the flow resistance and RBC-FL explains why cells can have a high concentration of hemoglobin for efficient oxygen delivery, without a pronounced increase in the flow resistance.
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。
