Numerical simulations are performed to examine the packing behavior of human red blood cells(RBCs). A combined ?nite-discrete element method(FDEM) is utilized, in which the RBCs are modeled as no-friction and no-adhes...Numerical simulations are performed to examine the packing behavior of human red blood cells(RBCs). A combined ?nite-discrete element method(FDEM) is utilized, in which the RBCs are modeled as no-friction and no-adhesion solid bodies. The packed volume and the void ratio of a large number of randomly packed RBCs are clari?ed,and the effects of the RBC shape, the mesh size, the cell number, and the container size are investigated. The results show that the packed human RBCs with normal shape have a void ratio of 28.45%, which is slightly higher than that of the ?at or thick cells used in this study. Such information is bene?cial to the further understanding on the geometric features of human RBCs and the research on RBC simulations.展开更多
Human red blood cells (RBCs) are responsible to transport oxygen and carbon dioxide for human bodies. The physiological functions of RBCs are greatly influenced by their mechanical properties. When RBC is infected by ...Human red blood cells (RBCs) are responsible to transport oxygen and carbon dioxide for human bodies. The physiological functions of RBCs are greatly influenced by their mechanical properties. When RBC is infected by Malaria parasite called Plasmodium falciparum, it shows progressive changes in mechanical properties and loses its deformability. The infected red blood cells (IRBCs) develop properties of cytoadherence (stickiness) and rosetting (the binding of non-infected RBCs to parasitized RBCs). In this paper to analyze the mechanical properties and deformability of the IRBC, we applied stress-stretch ratio relation of its biomembrane .To express this constitutive relation, we proposed a mathematical model (Neo-Hookean model) based on membrane theory. On this model, we present continuous stress-stretch ratio curves for the relation derived from the model for different intracellular developmental stages of the parasite, to determine the mechanical properties of IRBC. The analytical results obtained from the mathematical model are more closed with the experimental data [1] which demonstrates the validity of the model. By restricting our attention to spherically symmetric deformation in the final schizont stage of parasite development, the pressure-extension ratio relation curve also adapted from the proposed strain energy function. The change in osmotic pressure versus volumetric ratio has been also considered for IRBC before hemolysis.展开更多
The changes of blood perfusion and oxygen transport in tumors during tumor vascular normalization are studied with 3-dimensional mathematical modeling and numerical simulation. The models of tumor angiogenesis and vas...The changes of blood perfusion and oxygen transport in tumors during tumor vascular normalization are studied with 3-dimensional mathematical modeling and numerical simulation. The models of tumor angiogenesis and vascular-disrupting are used to simulate ＂un-normalized＂ and ＂normalized＂ vasculatures. A new model combining tumor hemodynamics and oxygen transport is developed. In this model, the intravasculartransvascular-interstitial flow with red blood cell（RBC） delivery is tightly coupled, and the oxygen resource is produced by heterogeneous distribution of hematocrit from the flow simulation. The results show that both tumor blood perfusion and hematocrit in the vessels increase, and the hypoxia microenvironment in the tumor center is greatly improved during vascular normalization. The total oxygen content inside the tumor tissue increases by about 67%, 51%, and 95% for the three approaches of vascular normalization,respectively. The elevation of oxygen concentration in tumors can improve its metabolic environment, and consequently reduce malignancy of tumor cells. It can also enhance radiation and chemotherapeutics to tumors.展开更多
目的探讨炎症条件的动物输注贮存红细胞对巨噬细胞(BMDMs)的调节作用以及贮存红细胞输注与细菌感染引发炎症反应的关系。方法将6~8周龄成年雄性C57BL/6小鼠[(18~22)g/只]40只随机均分为实验组和实验对照组(对照组),均通过动物尾静脉注...目的探讨炎症条件的动物输注贮存红细胞对巨噬细胞(BMDMs)的调节作用以及贮存红细胞输注与细菌感染引发炎症反应的关系。方法将6~8周龄成年雄性C57BL/6小鼠[(18~22)g/只]40只随机均分为实验组和实验对照组(对照组),均通过动物尾静脉注射铜绿假单胞菌200μL/只,并使用吸入式麻醉剂异氟烷(1%~3%)麻醉后,通过小鼠眼后静脉丛,实验组输注鼠源贮存悬浮红细胞(>14 d)400μL/只、对照组每只输注等量新鲜悬浮红细胞(贮存<24 h);于输注后2、4、8 h脱就猝死各结束2组小鼠生命5只,摘取鼠肝,体外培养铜绿假单胞菌感染(200μL/只)小鼠的股骨、胫骨骨髓来源的BMDMs,流式细胞术检测BMDMs中分化簇86(CD86)、分化簇197(CD197)[巨噬细胞1型(M1)基因特异性标志物]、分化簇209(CD209)[巨噬细胞2型(M2)基因特异性标记]表达水平,实时荧光定量PCR(qRT-PCR)法检测小鼠肝脏F4/80、M1、M2基因表达水平,并使用SPSS17.0统计学软件分析数据。结果实验组与对照组BMDMs中CD86和CD197的表达(%)分别为8688±1.01 vs 79.24±2.65、38.59±3.73 vs 25.95±0.86(P<0.05),CD209(%)为23.88±2.23 vs 21.91±3.58(P>0.05)。输注红细胞后2、4 h,小鼠肝F4/80基因表达水平实验组和对照组分别为1.83±0.11 vs 0.75±0.06、0.46±0.06 vs 0.33±0.06(P<0.05),8 h后分别为0.33±0.03 vs 0.35±0.05(P>0.05);输注红细胞2、4、8 h,小鼠肝M1基因中诱导型一氧化氮合酶(iNOS)基因表达水平实验组和对照组分别为3.44±0.20 vs 2.46±0.08、9.25±0.55 vs 2.67±0.12、2.80±0.08 vs 2.39±0.01,肿瘤坏死因子-α(TNF-α)分别为1.69±0.22 vs 1.13±0.03、1.44±0.24 vs 0.96±0.09、1.31±0.05 vs 0.96±0.06,单核细胞趋化蛋白1(MCP1)分别为4.96±0.08 vs 4.28±0.27、4.63±0.04 vs 2.07±0.09、2.28±0.19 vs 1.33±0.03(P<0.05);M2基因中精氨酸1(Arg1)基因表达水平实验组和对照组分别为0.81±0.21 vs 0.82±0.18、0.66±0.11 vs 0.58±0.09、0.39±0.17 vs 0.37±0.15,甘露糖受体C型2(Mrc2)分别为0.99±0.91 vs 0.97±0.08、0.98±0.12 vs 1.02±0.11、0.59±0.19 vs 0.57±0.08,重组蛋白163(CD163)分别为1.75±0.20 vs 1.69±0.18、0.22±0.02 vs 0.21±0.01、0.04±0.01 vs 0.03±0.01(P>0.05)。结论实验小鼠输注贮存红细胞明显促进其肝脏组织巨噬细胞朝向M1表型的极化。展开更多
基金Project supported by the Engineering and Physical Sciences Research Council(EPSRC)Turbulence Consortium Grant(No.EP/G069581/1)the Marie Curie International Incoming Fellowship(No.PIIF-GA-253453)
文摘Numerical simulations are performed to examine the packing behavior of human red blood cells(RBCs). A combined ?nite-discrete element method(FDEM) is utilized, in which the RBCs are modeled as no-friction and no-adhesion solid bodies. The packed volume and the void ratio of a large number of randomly packed RBCs are clari?ed,and the effects of the RBC shape, the mesh size, the cell number, and the container size are investigated. The results show that the packed human RBCs with normal shape have a void ratio of 28.45%, which is slightly higher than that of the ?at or thick cells used in this study. Such information is bene?cial to the further understanding on the geometric features of human RBCs and the research on RBC simulations.
文摘Human red blood cells (RBCs) are responsible to transport oxygen and carbon dioxide for human bodies. The physiological functions of RBCs are greatly influenced by their mechanical properties. When RBC is infected by Malaria parasite called Plasmodium falciparum, it shows progressive changes in mechanical properties and loses its deformability. The infected red blood cells (IRBCs) develop properties of cytoadherence (stickiness) and rosetting (the binding of non-infected RBCs to parasitized RBCs). In this paper to analyze the mechanical properties and deformability of the IRBC, we applied stress-stretch ratio relation of its biomembrane .To express this constitutive relation, we proposed a mathematical model (Neo-Hookean model) based on membrane theory. On this model, we present continuous stress-stretch ratio curves for the relation derived from the model for different intracellular developmental stages of the parasite, to determine the mechanical properties of IRBC. The analytical results obtained from the mathematical model are more closed with the experimental data [1] which demonstrates the validity of the model. By restricting our attention to spherically symmetric deformation in the final schizont stage of parasite development, the pressure-extension ratio relation curve also adapted from the proposed strain energy function. The change in osmotic pressure versus volumetric ratio has been also considered for IRBC before hemolysis.
基金Project supported by the National Natural Science Foundation of China(Nos.11102113 and81301816)the New Teachers Start Program of Shanghai Jiao Tong University+1 种基金the Chenxing Young Scholars Program B of Shanghai Jiao Tong University(No.13X100010070)the Natural Science Research Foundation of Shanghai Jiao Tong University School of Medicine(No.13XJ10037)
文摘The changes of blood perfusion and oxygen transport in tumors during tumor vascular normalization are studied with 3-dimensional mathematical modeling and numerical simulation. The models of tumor angiogenesis and vascular-disrupting are used to simulate ＂un-normalized＂ and ＂normalized＂ vasculatures. A new model combining tumor hemodynamics and oxygen transport is developed. In this model, the intravasculartransvascular-interstitial flow with red blood cell（RBC） delivery is tightly coupled, and the oxygen resource is produced by heterogeneous distribution of hematocrit from the flow simulation. The results show that both tumor blood perfusion and hematocrit in the vessels increase, and the hypoxia microenvironment in the tumor center is greatly improved during vascular normalization. The total oxygen content inside the tumor tissue increases by about 67%, 51%, and 95% for the three approaches of vascular normalization,respectively. The elevation of oxygen concentration in tumors can improve its metabolic environment, and consequently reduce malignancy of tumor cells. It can also enhance radiation and chemotherapeutics to tumors.
文摘目的探讨炎症条件的动物输注贮存红细胞对巨噬细胞(BMDMs)的调节作用以及贮存红细胞输注与细菌感染引发炎症反应的关系。方法将6~8周龄成年雄性C57BL/6小鼠[(18~22)g/只]40只随机均分为实验组和实验对照组(对照组),均通过动物尾静脉注射铜绿假单胞菌200μL/只,并使用吸入式麻醉剂异氟烷(1%~3%)麻醉后,通过小鼠眼后静脉丛,实验组输注鼠源贮存悬浮红细胞(>14 d)400μL/只、对照组每只输注等量新鲜悬浮红细胞(贮存<24 h);于输注后2、4、8 h脱就猝死各结束2组小鼠生命5只,摘取鼠肝,体外培养铜绿假单胞菌感染(200μL/只)小鼠的股骨、胫骨骨髓来源的BMDMs,流式细胞术检测BMDMs中分化簇86(CD86)、分化簇197(CD197)[巨噬细胞1型(M1)基因特异性标志物]、分化簇209(CD209)[巨噬细胞2型(M2)基因特异性标记]表达水平,实时荧光定量PCR(qRT-PCR)法检测小鼠肝脏F4/80、M1、M2基因表达水平,并使用SPSS17.0统计学软件分析数据。结果实验组与对照组BMDMs中CD86和CD197的表达(%)分别为8688±1.01 vs 79.24±2.65、38.59±3.73 vs 25.95±0.86(P<0.05),CD209(%)为23.88±2.23 vs 21.91±3.58(P>0.05)。输注红细胞后2、4 h,小鼠肝F4/80基因表达水平实验组和对照组分别为1.83±0.11 vs 0.75±0.06、0.46±0.06 vs 0.33±0.06(P<0.05),8 h后分别为0.33±0.03 vs 0.35±0.05(P>0.05);输注红细胞2、4、8 h,小鼠肝M1基因中诱导型一氧化氮合酶(iNOS)基因表达水平实验组和对照组分别为3.44±0.20 vs 2.46±0.08、9.25±0.55 vs 2.67±0.12、2.80±0.08 vs 2.39±0.01,肿瘤坏死因子-α(TNF-α)分别为1.69±0.22 vs 1.13±0.03、1.44±0.24 vs 0.96±0.09、1.31±0.05 vs 0.96±0.06,单核细胞趋化蛋白1(MCP1)分别为4.96±0.08 vs 4.28±0.27、4.63±0.04 vs 2.07±0.09、2.28±0.19 vs 1.33±0.03(P<0.05);M2基因中精氨酸1(Arg1)基因表达水平实验组和对照组分别为0.81±0.21 vs 0.82±0.18、0.66±0.11 vs 0.58±0.09、0.39±0.17 vs 0.37±0.15,甘露糖受体C型2(Mrc2)分别为0.99±0.91 vs 0.97±0.08、0.98±0.12 vs 1.02±0.11、0.59±0.19 vs 0.57±0.08,重组蛋白163(CD163)分别为1.75±0.20 vs 1.69±0.18、0.22±0.02 vs 0.21±0.01、0.04±0.01 vs 0.03±0.01(P>0.05)。结论实验小鼠输注贮存红细胞明显促进其肝脏组织巨噬细胞朝向M1表型的极化。
