Blood Flows and Blood-Vessel Interactions in the Microcirculation

血液的重要性怎么强调都不过分。血液在体内不断循环，执行许多重要的生物功能，包括向组织供应氧气和营养物以及从组织中清除代谢废物;白色血细胞、抗体和血小板的循环，用于免疫和自我修复;以及调节身体pH值和温度。这些血液功能主要是在由微血管和毛细血管组成的微血管网中完成的。在基础研究和临床观察中发现，异常的微观血流行为往往与心脏病、高血压、糖尿病、癌症、疟疾、贫血、动脉粥样硬化等多种疾病有关。在微循环中，由于血细胞的大小与微血管和毛细血管相当，因此不能将血液视为连续流体。为了研究微观血液流动，我们将开发以悬浮在血浆中的三维柔性胶囊表示的红细胞的数值模型。血流与微血管表面蛋白质纤维之间的动态相互作用将被仔细研究，因为它在许多生物功能和过程中起着重要作用。我们还将研究各种细胞，流量和血管参数对微血管网络中血流行为和功能的影响。该计划将提高我们对微循环中复杂血流行为的认识;因此，它可以提高我们对异常血液特性如何影响高血压，糖尿病或疟疾患者血液功能的理解。从这项研究中获得的信息也可以使相关的生物医学和临床应用受益，例如严重出血的血液替代品开发，生物芯片血液分析，以及微循环中血液流动的纳米颗粒运输用于药物输送。

The importance of blood can never be overemphasized. Continuously circulating through the body, blood performs many crucial biological functions, including supply of oxygen and nutrients to and removal of metabolic wastes from tissues; circulation of white blood cells, antibodies and platelets for immunization and self-repair; and regulation of body pH and temperature. These blood functions are mainly accomplished in the microvascular network composed of microvessels and capillaries. As observed in fundamental studies and clinical observations, abnormal microscopic blood flow behaviors are often associated with various diseases and disorders, such as heart diseases, hypertension, diabetes, cancers, malaria, anemia, and atherosclerosis.In the microcirculation, blood cannot be treated as a continuum fluid, since the blood cells are comparable to the microvessels and capillaries in size. To study microscopic blood flows, we will develop numerical models with red blood cells represented as three-dimensional flexible capsules suspended in plasma. The dynamic interaction between blood flows and the protein fibers on microvessel surfaces will be carefully examined for its important role in many biological functions and processes. We will also investigate the effects of various cell, flow, and vessel parameters on the blood flow behaviors and functions in the microvascular network.This program will advance our knowledge of the complex blood flow behaviors in the microcirculation; and it can therefore improve our understanding of how abnormal blood properties can affect blood functions in patients with, for example, hypertension, diabetes, or malaria. Information obtained from this research can also benefit relevant biomedical and clinical applications, such as blood substitute development for severe hemorrhage, blood analysis with biochips, and nanoparticle transport with blood flows in the microcirculation for drug delivery.