Igor Pivkin

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We develop a systematic coarse-graining procedure for modeling red blood cells (RBCs) using arguments based on mean-field theory. The three-dimensional RBC membrane model takes into account the bending energy, in-plane shear energy, and constraints of fixed surface area and fixed enclosed volume. The coarse-graining procedure is general, it can be used for(More)
Mural thrombi are composed dominantly of platelets and develop under a blood flow. Portions can break off and are carried in the blood flow as emboli. Thrombus growth rates are affected by the velocity of the blood flow, but they do not simply increase with it, they exhibit a maximum, with subsequent decrease. Whereas this variation indicates an interaction(More)
Malaria resulting from Plasmodium falciparum infection is a major cause of human suffering and mortality. Red blood cell (RBC) deformability plays a major role in the pathogenesis of malaria. Here we introduce an automated microfabricated "deformability cytometer" that measures dynamic mechanical responses of 10(3) to 10(4) individual RBCs in a cell(More)
Dissipative particle dynamics (DPD) is a potentially very effective approach in simulating mesoscale hydrodynamics. However, because of the soft potentials employed, the simple no-slip boundary conditions are difficult to impose. In this work, we first identify some of these difficulties and subsequently we propose a new method, based on an equivalent force(More)
We study the biomechanical interactions between the lipid bilayer and the cytoskeleton in a red blood cell (RBC) by developing a general framework for mesoscopic simulations. We treated the lipid bilayer and the cytoskeleton as two distinct components and developed a unique whole-cell model of the RBC, using dissipative particle dynamics (DPD). The model is(More)
Dissipative Particle Dynamics (DPD) simulations of wall-bounded flows exhibit density fluctuations that depend strongly on the no-slip boundary condition and increase with the level of coarse graining. We develop an adaptive model for wall-particle interactions that eliminates such oscillations and can target prescribed density profiles. Comparisons are(More)
Problem We present a method for simulating and visualizing air flow around a static bat (order Chiroptera) wing geometry. This demonstration serves as proof-of-concept for simulating and visualizing air flow around a time-varying geometry in order to understand the aerodynamic principles behind bat flight. By understanding the mechanics of bat flight, we(More)
The blood cell that plays a central role in the normal clotting process is the platelet. Blood platelets were first discovered by Donne in 1842 [1], but 40 years later, Bizzozero [2] recognized the importance of platelet clumping in the blood clotting process. It is now well established that platelet aggregation is not only important for primary hemostasis(More)