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
In this article we consider the kth-order discrete delay survival red blood cells model. The general form of the discrete dynamical system is rewritten as Xn＋l = f（Pn,δn,xn,... ,xn＋1） where Pn,δn converge to the...In this article we consider the kth-order discrete delay survival red blood cells model. The general form of the discrete dynamical system is rewritten as Xn＋l = f（Pn,δn,xn,... ,xn＋1） where Pn,δn converge to the parametric values P and 6. We show that when the parameters are replaced by sequences, the stability results of the original system still hold.展开更多
In this paper, we deal with a model for the survival of red blood cells with periodic coefficients x＇（g）=-μ（t）x（t）＋P（t）e^-γ（t）x（t-τ（t））,t≥0.（＊）A new sufficient condition for global attractivity ...In this paper, we deal with a model for the survival of red blood cells with periodic coefficients x＇（g）=-μ（t）x（t）＋P（t）e^-γ（t）x（t-τ（t））,t≥0.（＊）A new sufficient condition for global attractivity of positive periodic solutions of Eq. （＊） is obtained. Our criterion improves corresponding result obtained by Li and Wang in 2005.展开更多
In this article, a computational model and related methodologies have been tested for simulating the motion of a malaria infected red blood cell （iRBC for short） in Poiseuille flow at low Reynolds numbers. Besides t...In this article, a computational model and related methodologies have been tested for simulating the motion of a malaria infected red blood cell （iRBC for short） in Poiseuille flow at low Reynolds numbers. Besides the deformability of the red blood cell membrane, the migration of a neutrally buoyant particle （used to model the malaria parasite inside the membrane） is another factor to determine the iRBC motion. Typically an iRBC oscillates in a Poiseuille flow due to the competition between these two factors. The interaction of an iRBC and several RBCs in a narrow channel shows that, at lower flow speed, the iRBC can be easily pushed toward the wall and stay there to block the channel. But, at higher flow speed, RBCs and iRBC stay in the central region of the channel since their migrations axe dominated by the motion of the RBC membrane.展开更多
In this paper,we are concerned with a class of fractional-order Lasota-Wazewska red blood ccll modcls.By applying a fixed point theorem on a normal cone,we first obtain the sufficient conditions for the existence of a...In this paper,we are concerned with a class of fractional-order Lasota-Wazewska red blood ccll modcls.By applying a fixed point theorem on a normal cone,we first obtain the sufficient conditions for the existence of a unique almost periodic positive solution of the considered models.Then,considering that all of the red blood cells in animals survive in a finite-time interval,we study the finite-time stability of the almost periodic positive solution by using some inequality techniques.Our results and methods of this paper are new.Finally,we give numerical examples to show the feasibility of the obtained results.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.
文摘In this article we consider the kth-order discrete delay survival red blood cells model. The general form of the discrete dynamical system is rewritten as Xn＋l = f（Pn,δn,xn,... ,xn＋1） where Pn,δn converge to the parametric values P and 6. We show that when the parameters are replaced by sequences, the stability results of the original system still hold.
基金the National Natural Science Foundation of China(No.10271044)Research Fund of Hunan Provincial Education Department(No.06C719)
文摘In this paper, we deal with a model for the survival of red blood cells with periodic coefficients x＇（g）=-μ（t）x（t）＋P（t）e^-γ（t）x（t-τ（t））,t≥0.（＊）A new sufficient condition for global attractivity of positive periodic solutions of Eq. （＊） is obtained. Our criterion improves corresponding result obtained by Li and Wang in 2005.
基金supported by the National Science Foundation of the United States(Nos.DMS-0914788,DMS-1418308)
文摘In this article, a computational model and related methodologies have been tested for simulating the motion of a malaria infected red blood cell （iRBC for short） in Poiseuille flow at low Reynolds numbers. Besides the deformability of the red blood cell membrane, the migration of a neutrally buoyant particle （used to model the malaria parasite inside the membrane） is another factor to determine the iRBC motion. Typically an iRBC oscillates in a Poiseuille flow due to the competition between these two factors. The interaction of an iRBC and several RBCs in a narrow channel shows that, at lower flow speed, the iRBC can be easily pushed toward the wall and stay there to block the channel. But, at higher flow speed, RBCs and iRBC stay in the central region of the channel since their migrations axe dominated by the motion of the RBC membrane.
基金the National Natural Sciences Foundation of People's Republic of China under Grants Nos.11861072 and 11361072the Applied Basic Research Programs of Science and Technology Department of Yunnan Province under Grant No.2019FBO03.
文摘In this paper,we are concerned with a class of fractional-order Lasota-Wazewska red blood ccll modcls.By applying a fixed point theorem on a normal cone,we first obtain the sufficient conditions for the existence of a unique almost periodic positive solution of the considered models.Then,considering that all of the red blood cells in animals survive in a finite-time interval,we study the finite-time stability of the almost periodic positive solution by using some inequality techniques.Our results and methods of this paper are new.Finally,we give numerical examples to show the feasibility of the obtained results.
