Particle trapping by an external body force in the limit of large Peclet number: applications to magnetic targeting in the blood flow
Particle trapping by an external body force in the limit of large Peclet number: applications to magnetic targeting in the blood flow
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大佩克莱数极限下的外部体力捕获粒子：在血流中磁靶向的应用
DOI：
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发表时间：
2010
影响因子：
1.9
通讯作者：
H. Byrne
中科院分区：
文献类型：
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作者：
G. Richardson;K. Kaouri;H. Byrne
受磁性靶向药物和基因递送技术（其中磁场用于将磁性载体颗粒从循环引导至目标位点）的推动，我们开发了一种连续体模型，用于在中性浮力颗粒（血液）的浓缩悬浮液流中受到外部体力（磁场）影响的颗粒（磁性载体）的运动。平流扩散方程描述了载体颗粒在外部体力的作用下在流动中平流时的演变，并由于与中性浮力颗粒悬浮液的随机相互作用而扩散（剪切诱导扩散）。该模型针对圆柱形容器中存在稳定泊肃叶流、扩散效应较弱且沿容器壁的载流子吸收较弱的情况进行分析。匹配渐近展开的方法用于表明载流子集中在沿容器壁的边界层中，此外，沿该层存在载流子通量，这导致沿容器一侧的子层，其中载流子更加高度集中。确定了三个不同的限制：它们对应于以下情况：（i）力足够弱，使得大多数颗粒移动穿过容器而不会沿着容器壁进入边界层，以及（ii）和（iii）力足够强，使得大部分颗粒进入边界层，并且根据容器壁的载流子吸收，这些层中存在微不足道/显着的轴向载流子通量。
Motivated by the technology of magnetically targeted drug and gene delivery, in which a magnetic field is used to direct magnetic carrier particles from the circulation to a target site, we develop a continuum model for the motion of particles (magnetic carriers) subject to an external body force (magnetic field) in a flow of a concentrated suspension of a species of neutrally buoyant particles (blood). An advection–diffusion equation describes the evolution of the carrier particles as they advect in the flow under the action of an external body force, and diffuse as a result of random interactions with the suspension of neutrally buoyant particles (shear-induced diffusion). The model is analysed for the case in which there is steady Poiseuille flow in a cylindrical vessel, the diffusive effects are weak and there is weak carrier uptake along the walls of the vessel. The method of matched asymptotic expansions is used to show that carriers are concentrated in a boundary layer along the vessel wall and, further, that there is a carrier flux along this layer which results in a sub-layer, along one side of the vessel, in which carriers are even more highly concentrated. Three distinguished limits are identified: they correspond to cases for which (i) the force is sufficiently weak that most particles move through the vessel without entering the boundary layers along the walls of the vessel and (ii) and (iii) to a force which is sufficiently strong that a significant fraction of the particles enter the boundary layers and, depending upon the carrier absorption from the vessel walls, there is insignificant/significant axial carrier flux in these layers.
影响因子：
12.4
作者：
Mah, C;Fraites, TJ;Byrne, BJ
通讯作者：
Byrne, BJ