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I.IntroductionCancerhasbeenthekillerinmanywesterncountriesonlysecondtothecardiovasculardiseaseformanyyears.Ditficultiesinearlydiagnosisisoneofthemajorobstaclesincancertreatment.However,recentlyitisreportedthatthetumorphysiologicalbarrier,whichpreventsdrugsfrompenetratingintothecoreoftumor,'mayconstituteanothermajorobstacleinkillingcancercallseffectivelyl'].Therefore,tostudythemasstransp.ortprocessintumorbecomesimportantinthatitmayprovidesomecriteriafordrugdesignanddrug-giningstrategies.Tradit… 相似文献
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A numerical analysis of the steady/pulsatile flow and macromolecular (such as LDL and Albumin) transport in curved blood vessels was carried out. The computational results predict that the vortex of the secondary flow is time-dependent in the aortic arch. The concentration of macromolecule concentrates at the region of sharp curve, and the wall concentration at the outer part is higher than that at the inner part. Atherosclerosis and thrombosis are prone to develop in such regions with sharp flow. 相似文献
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T型分叉血管的定常/脉动流动和大分子传质 总被引:1,自引:1,他引:0
采用计算流体动力学方法,数值求解了T型分叉流动的定常/脉动流场和低密度脂蛋白(LDL)以及血清白蛋白(Albumin)的浓度分布。计算了雷诺数、主管和支管的流量比等参数对流场和大分子传质的影响,计算结果表明,流体动力学因素影响大分子的分布和跨壁渗透,在动脉硬化的发生和发展过程中起着重要的作用。在流动发生分离处,即支管入口外侧壁面剪应力变化最剧烈,这儿LDL和Albumin的壁面浓度变化也是最剧烈,是动脉硬化危险区。 相似文献
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IntroductionCardiovascularsystemisanextremelycomplexcouplingsysteminwhichleftventricle(LV)andsystemicarteries(SA)interactwith... 相似文献
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心室的后负荷、泵功能及与动脉的耦合 总被引:4,自引:0,他引:4
近20年来心室后负荷、泵功能及心室-动脉耦合的研究已有了很大的发展和某些医疗应用.在静态情况下,这一问题的研究已比较成熟.对于动态情形,目前已作了不少动物实验,并提出一些理论模型.本文首先评述20多年来这一问题的发展概况,然后报告笔者近期的研究结果,最后提出进一步需要研究的问题 相似文献
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The formation of atherosclerosis in a curved a-orta is closely related to the existence of separa-ted vortex region.This paper deals with the steadylaminar motion of an incompressible Newtonian fluidthrough a curved tube with circular cross-sectionwhose curvature is small and whose curvature gra-dient is not too large.Using the momentum integralmethod and the approximation of quasi-constant cur-vature.an equation which determines the location ofseparation and reattachment is derived.From thisequation the earliest point of separation and thecorresponding critical Reynolds number are obtained.and the relation between the position of separationand reattachment and Reynolds number R_e for differ-ent azimuthal angle are revealed.It is concludedthat the separation first emerges at the positionwhose curvature qradient has the maximum absolute va-lue.with increasing R_e,the separation region ex-tends in the direction of mainstream.azimuthal angleand radius vector,and then forms a three-dimensionalseparated vort 相似文献
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在磁场作用下竖直管中有限长液柱的粘性流体运动 总被引:2,自引:0,他引:2
血栓的形成与血液动力学有密切关系.Chandler环的实验及进一步的研究表明,Chandler环中下弯月面处血栓的形成或许是因为流冲击下弯月面,使血小板和红细胞发生聚集所致。本文研究了竖直管中有限长液柱的粘性流体在磁场作用下的流动状况,应用有限差分方法进行了数值求解。计算结果表明,在适当的磁场强度下,管的下半部分管轴附近的轴向流速度较未加磁时有所减弱,从而减轻了流对下弯月面的撞击作用,可以有效地防止下弯月面处血栓的形成,而且磁场越强,这种减弱作用越明显,这一结果为进一步探求血栓的防治及其形成机制的实验研究有一定指导意义。 相似文献
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Moving Boundary Problem for Diffusion Release of Drug from a Cylinder Polymeric Matrix 总被引:1,自引:0,他引:1
IntroductionThediffusionreleaseofdrugfromapolymericmatrixisanimportantprobleminthedrugcontrolledreleasesystem .Itisoneofthemaincurrentdirectionsforexploitingnewdrugsthatthecontrolledreleasedrugwasmadebyputtingtheeffectivetreatmentdrugintopolymericmatr… 相似文献