The Experts below are selected from a list of 408 Experts worldwide ranked by ideXlab platform
Nadeeshani Maheshika Geekiyanage - One of the best experts on this subject based on the ideXlab platform.
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Deformation behaviour of stomatocyte, discocyte and Echinocyte red blood cell morphologies during optical tweezers stretching
Biomechanics and Modeling in Mechanobiology, 2020Co-Authors: Nadeeshani Maheshika Geekiyanage, Emilie Sauret, Suvash C. Saha, Robert L. Flower, Y. T. GuAbstract:The red blood cell (RBC) deformability is a critical aspect, and assessing the cell deformation characteristics is essential for better diagnostics of healthy and deteriorating RBCs. There is a need to explore the connection between the cell deformation characteristics, cell morphology, disease states, storage lesion and cell shape-transformation conditions for better diagnostics and treatments. A numerical approach inspired from the previous research for RBC morphology predictions and for analysis of RBC deformations is proposed for the first time, to investigate the deformation characteristics of different RBC morphologies. The present study investigates the deformability characteristics of stomatocyte, discocyte and Echinocyte morphologies during optical tweezers stretching and provides the opportunity to study the combined contribution of cytoskeletal spectrin network and the lipid-bilayer during RBC deformation. The proposed numerical approach predicts agreeable deformation characteristics of the healthy discocyte with the analogous experimental observations and is extended to further investigate the deformation characteristics of stomatocyte and Echinocyte morphologies. In particular, the computer simulations are performed to investigate the influence of direct stretching forces on different equilibrium cell morphologies on cell spectrin link extensions and cell elongation index, along with a parametric analysis on membrane shear modulus, spectrin link extensibility, bending modulus and RBC membrane–bead contact diameter. The results agree with the experimentally observed stiffer nature of stomatocyte and Echinocyte with respect to a healthy discocyte at experimentally determined membrane characteristics and suggest the preservation of relevant morphological characteristics, changes in spectrin link densities and the primary contribution of cytoskeletal spectrin network on deformation behaviour of stomatocyte, discocyte and Echinocyte morphologies during optical tweezers stretching deformation. The numerical approach presented here forms the foundation for investigations into deformation characteristics and recoverability of RBCs undergoing storage lesion.
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A coarse-grained red blood cell membrane model to study stomatocyte-discocyte-Echinocyte morphologies
PLOS ONE, 2019Co-Authors: Nadeeshani Maheshika Geekiyanage, Emilie Sauret, Suvash C. Saha, Robert L. Flower, Marie Anne Balanant, Chwee Teck LimAbstract:An improved red blood cell (RBC) membrane model is developed based on the bilayer coupling model (BCM) to accurately predict the complete sequence of stomatocyte-discocyte-Echinocyte (SDE) transformation of a RBC. The coarse-grained (CG)–RBC membrane model is proposed to predict the minimum energy configuration of the RBC from the competition between lipid-bilayer bending resistance and cytoskeletal shear resistance under given reference constraints. In addition to the conventional membrane surface area, cell volume and bilayer-leaflet-area-difference constraints, a new constraint: total-membrane-curvature is proposed in the model to better predict RBC shapes in agreement with experimental observations. A quantitative evaluation of several cellular measurements including length, thickness and shape factor, is performed for the first time, between CG-RBC model predicted and three-dimensional (3D) confocal microscopy imaging generated RBC shapes at equivalent reference constraints. The validated CG-RBC membrane model is then employed to investigate the effect of reduced cell volume and elastic length scale on SDE transformation, to evaluate the RBC deformability during SDE transformation, and to identify the most probable RBC cytoskeletal reference state. The CG-RBC membrane model can predict the SDE shape behaviour under diverse shape-transforming scenarios, in-vitro RBC storage, microvascular circulation and flow through microfluidic devices.
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Modelling the deformation behavior of stomatocyte, discocyte and Echinocyte red blood cell morphologies during optical tweezers stretching
2019Co-Authors: Nadeeshani Maheshika Geekiyanage, Emilie Sauret, Suvash C. Saha, Robert L. FlowerAbstract:A coarse-grained (CG) red blood cell (RBC) membrane model is used to investigate the deformation behavior of stomatocyte, discocyte and Echinocyte morphologies during optical tweezers stretching. First, the numerically predicted discocyte deformation behavior is validated against analogous experimental observations, and then the numerically predicted stomatocyte and Echinocyte deformation behavior is compared to the discocyte deformation behavior. The findings indicate that the CG-RBC membrane model is capable of accurately predicting the deformation behavior of stomatocyte, discocyte and Echinocyte RBC morphologies during optical tweezers stretching, and an applicable tool to investigate the evolution of RBC behavior and membrane properties for different morphologies.
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Shape Factor for CG-RBC membrane model predicted stomatocyte IV—Echinocyte IV RBC shapes.
2019Co-Authors: Nadeeshani Maheshika Geekiyanage, Emilie Sauret, Marie Anne Balanant, Suvash Saha, Robert Flower, Chwee Teck LimAbstract:Shape Factor for CG-RBC membrane model predicted stomatocyte IV—Echinocyte IV RBC shapes.
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CG-RBC membrane model predicted stomatocyte II, discocyte and Echinocyte II shapes at varying elastic length scale, = 0.11, 0.18, 0.25, 0.35 and 0.56. The coloured regions of the Echinocyte II shape represent the membrane curvature on its’ vertex po
2019Co-Authors: Nadeeshani Maheshika Geekiyanage, Emilie Sauret, Marie Anne Balanant, Suvash Saha, Robert Flower, Chwee Teck LimAbstract:CG-RBC membrane model predicted stomatocyte II, discocyte and Echinocyte II shapes at varying elastic length scale, = 0.11, 0.18, 0.25, 0.35 and 0.56. The coloured regions of the Echinocyte II shape represent the membrane curvature on its’ vertex points .
Ranjan Mukhopadhyay - One of the best experts on this subject based on the ideXlab platform.
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Echinocyte shapes: bending, stretching and shear determine spicule shape and spacing, Biophys
2015Co-Authors: Ranjan Mukhopadhyay, Gerald Lim H. W, Michael WortisAbstract:ABSTRACT We study the shapes of human red blood cells using continuum mechanics. In particular, we model the crenated, echinocytic shapes and show how they may arise from a competition between the bending energy of the plasma membrane and the stretching/shear elastic energies of the membrane skeleton. In contrast to earlier work, we calculate spicule shapes exactly by solving the equations of continuum mechanics subject to appropriate boundary conditions. A simple scaling analysis of this competition reveals an elastic length el, which sets the length scale for the spicules and is, thus, related to the number of spicules experimentally observed on the fully developed Echinocyte
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stomatocyte discocyte Echinocyte sequence of the human red blood cell evidence for the bilayer couple hypothesis from membrane mechanics
Proceedings of the National Academy of Sciences of the United States of America, 2002Co-Authors: Michael Wortis, Ranjan MukhopadhyayAbstract:Red-cell shape is encoded in the mechanical properties of the membrane. The plasma membrane contributes bending rigidity; the protein-based membrane skeleton contributes stretch and shear elasticity. When both effects are included, membrane mechanics can reproduce in detail the full stomatocyte–discocyte–Echinocyte sequence by variation of a single parameter related to the bilayer couple originally introduced by Sheetz and Singer [Sheetz, M. P. & Singer, S. J. (1974) Proc. Natl. Acad. Sci. USA 71, 4457–4461].
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Stomatocyte–discocyte–Echinocyte sequence of the human red blood cell: Evidence for the bilayer– couple hypothesis from membrane mechanics
Proceedings of the National Academy of Sciences of the United States of America, 2002Co-Authors: H.w. Gerald Lim, Michael Wortis, Ranjan MukhopadhyayAbstract:Red-cell shape is encoded in the mechanical properties of the membrane. The plasma membrane contributes bending rigidity; the protein-based membrane skeleton contributes stretch and shear elasticity. When both effects are included, membrane mechanics can reproduce in detail the full stomatocyte–discocyte–Echinocyte sequence by variation of a single parameter related to the bilayer couple originally introduced by Sheetz and Singer [Sheetz, M. P. & Singer, S. J. (1974) Proc. Natl. Acad. Sci. USA 71, 4457–4461].
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Echinocyte shapes bending stretching and shear determine spicule shape and spacing
Biophysical Journal, 2002Co-Authors: Ranjan Mukhopadhyay, H Gerald W Lim, Michael WortisAbstract:Abstract We study the shapes of human red blood cells using continuum mechanics. In particular, we model the crenated, echinocytic shapes and show how they may arise from a competition between the bending energy of the plasma membrane and the stretching/shear elastic energies of the membrane skeleton. In contrast to earlier work, we calculate spicule shapes exactly by solving the equations of continuum mechanics subject to appropriate boundary conditions. A simple scaling analysis of this competition reveals an elastic length Λ el , which sets the length scale for the spicules and is, thus, related to the number of spicules experimentally observed on the fully developed Echinocyte.
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Echinocyte shapes bending stretching and shear determine spicule shape and spacing
arXiv: Soft Condensed Matter, 2001Co-Authors: Ranjan Mukhopadhyay, H Gerald W Lim, Michael WortisAbstract:We study the shapes of human red blood cells using continuum mechanics. In particular, we model the crenated, echinocytic shapes and show how they may arise from a competition between the bending energy of the plasma membrane and the stretching/shear elastic energies of the membrane skeleton. In contrast to earlier work, we calculate spicule shapes exactly by solving the equations of continuum mechanics subject to appropriate boundary conditions. A simple scaling analysis of this competition reveals an elastic length which sets the length scale for the spicules and is, thus, related to the number of spicules experimentally observed on the fully developed Echinocyte.
F Jung - One of the best experts on this subject based on the ideXlab platform.
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effect of radiographic contrast media iodixanol iopromide on the spectrin actin network of the membranous cytoskeleton of erythrocytes
Clinical Hemorheology and Microcirculation, 2013Co-Authors: R P Franke, Tim Scharnweber, R Fuhrmann, Christof Mrowietz, F JungAbstract:Red blood cells demonstrate a unique ability for repeated large deformation. Under the influence of a variety of agents, shapes other than the discocyte - e.g. stomatocytes or Echinocytes - can be observed. Some radiographic agents induce shape changes from discocytic to echinocytic cells. Especially the Echinocyte formation is associated with a rigidification of the cells bearing the risk of a hindered capillary passage of the Echinocytes. The mechanisms leading to the formation of Echinocytes are not well understood assuming that the membrane cytoskeleton is a key player. That is why this examination was focused on the participation of components of the membrane cytoskeleton in the formation of Echinocytes and the protrusions accompanying the formation of Echinocytes. Two radiographic contrast media approved for intra-arterial application were used to study Echinocyte formation (Iodix- anol320; Iopromide370). In the in vitro study serious changes in the membrane cytoskeleton were only found in those erythrocytes incubated in plasma supplemented with Iopromide370 (30%v/v). The shape of the spectrin net was completely altered; from the more homogeneous distribution - typical of cells in autologous plasma and also of cells in plasma supplemented with Iodixanol320 - to a distribution of spectrin concentrated in the membrane-near regions with the appearance of spectrin-actin co-localization. Co-localized spectrin with actin was also found around the membranous roots of protrusions which resemble exocytotic processes. In central parts of the cells there was a pronounced dissociation of spectrin and actin; green coloured condensed spectrin bundles originating from the cell membrane reached up to the root of the protrusions. Separate from this there were also fine long actin fibres passing through the whole cell. The incubation of erythrocytes in plasma supplemented with Iopromide370 induced rounded bubble-like protrusions from the cell membrane containing almost completely long bundles of actin fibres. The examination confirmed earlier studies showing that some radiographic contrast media are able to induce Echinocyte formation. Furthermore, subcellular mechanisms were revealed explaining the different effects of Iodixanol in comparison to Iopromide.
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influence of different radiographic contrast media on the Echinocyte formation of human erythrocytes
16th International Conference of the European Society for Clinical Hemorheology and Microcirculation (ESCHM) and the 30th Annual Conference of the Ger, 2011Co-Authors: Christof Mrowietz, R P Franke, F JungAbstract:Echinocyte formation is associated with a rigidification of the cells that may affect capillary perfusion and, consequently, the tissue oxygen supply. This study examines how many Echinocytes appeared after the addition of radiographic contrast media (RCM) (Iodixanol320, Ioversol300, Iopamidol300, and Iomeprol400) compared to red blood cells in autologous plasma and in isotonic saline solution. Isotonic saline solution, Iodixanol, Ioversol, Iopamidol and Iomeprol in concentrations of 10 vol%, 20 vol%, and 40 vol% were added to the plasma of seven healthy subjects. Subsequently, the erythrocytes were resuspended in these plasma/RCM mixtures, incubated for 5 minutes and then examined under the microscope. The concentrations and the RCM in the mixture had a significant effect on the number of discocytes (factor concentration: p < 0.0001; factor RCM: p < 0.0001). The percentage of discocytes for all concentrations depended significantly on the RCM/plasma mixture (concentration × RCM: p < 0.002). Of all RCM/plasma mixtures used, the Iodixanol/plasma mixture showed the most similar discocyte fraction compared to red blood cells in the autologous plasma. Importantly, while Iodixanol differed from all other RCMs, the other RCMs did not differ from one another with respect to the discocyte fraction.
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reversibility of Echinocyte formation after contact of erythrocytes with various radiographic contrast media
Clinical Hemorheology and Microcirculation, 2008Co-Authors: C Mrowietz, B Hiebl, R P Franke, Jaiwun Park, F JungAbstract:Various radiographic contrast media (RCM) significantly influence the morphology of erythrocytes, especially the formation of Echinocytes [Scand. J. Clin. Lab. Invest. 35 (1975), 1-43; Microvasc. Res. 60 (2000), 193-200; Herz 23 (2003), 35-41]. Microscopic studies, however, have shown that these changes of erythrocyte morphology are possibly reversible [Acta Radiol. 37 (1996), 214-217]. The aim of this study was to proof if the RCM-induced Echinocyte formation can be reversed by a resuspension in autologous plasma. In this study four RCMs were tested (Iodixanol, Iohexol, Iomeprol and Iopromide). These RCM induced Echinocyte formation (after suspension of erythrocytes in plasma/RCM mixtures for 10 min at 37 degrees C), which was reversible after resuspension in autologous RCM-free plasma (resuspension time 5 min at 37 degrees C). Especially for Iomeprol and Iopromide - the RCMs which induced the strongest Echinocyte formation - an Echinocyte reduction from 94.2% to 44.5% and for Iopromide from 80.6% to 50.4% occurred. The Echinocyte formation was influenced by the type of RCM as well as by the RCM concentration. The same was true for the reversibility of Echinocyte formation due to resuspension in autologous plasma (type of RCM: pEchinocytes formed (after suspension in the plasma/RCM-mixture as well as after the resuspension in autologous plasma). A 100% reversibility back to discocytes was observed in none of the RCMs after resuspension in autologous RCM-free plasma.In conclusion, a significant reversibility of RCM-induced Echinocyte formation in autologous plasma could be observed.
Michael Wortis - One of the best experts on this subject based on the ideXlab platform.
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Echinocyte shapes: bending, stretching and shear determine spicule shape and spacing, Biophys
2015Co-Authors: Ranjan Mukhopadhyay, Gerald Lim H. W, Michael WortisAbstract:ABSTRACT We study the shapes of human red blood cells using continuum mechanics. In particular, we model the crenated, echinocytic shapes and show how they may arise from a competition between the bending energy of the plasma membrane and the stretching/shear elastic energies of the membrane skeleton. In contrast to earlier work, we calculate spicule shapes exactly by solving the equations of continuum mechanics subject to appropriate boundary conditions. A simple scaling analysis of this competition reveals an elastic length el, which sets the length scale for the spicules and is, thus, related to the number of spicules experimentally observed on the fully developed Echinocyte
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stomatocyte discocyte Echinocyte sequence of the human red blood cell evidence for the bilayer couple hypothesis from membrane mechanics
Proceedings of the National Academy of Sciences of the United States of America, 2002Co-Authors: Michael Wortis, Ranjan MukhopadhyayAbstract:Red-cell shape is encoded in the mechanical properties of the membrane. The plasma membrane contributes bending rigidity; the protein-based membrane skeleton contributes stretch and shear elasticity. When both effects are included, membrane mechanics can reproduce in detail the full stomatocyte–discocyte–Echinocyte sequence by variation of a single parameter related to the bilayer couple originally introduced by Sheetz and Singer [Sheetz, M. P. & Singer, S. J. (1974) Proc. Natl. Acad. Sci. USA 71, 4457–4461].
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Stomatocyte–discocyte–Echinocyte sequence of the human red blood cell: Evidence for the bilayer– couple hypothesis from membrane mechanics
Proceedings of the National Academy of Sciences of the United States of America, 2002Co-Authors: H.w. Gerald Lim, Michael Wortis, Ranjan MukhopadhyayAbstract:Red-cell shape is encoded in the mechanical properties of the membrane. The plasma membrane contributes bending rigidity; the protein-based membrane skeleton contributes stretch and shear elasticity. When both effects are included, membrane mechanics can reproduce in detail the full stomatocyte–discocyte–Echinocyte sequence by variation of a single parameter related to the bilayer couple originally introduced by Sheetz and Singer [Sheetz, M. P. & Singer, S. J. (1974) Proc. Natl. Acad. Sci. USA 71, 4457–4461].
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Echinocyte shapes bending stretching and shear determine spicule shape and spacing
Biophysical Journal, 2002Co-Authors: Ranjan Mukhopadhyay, H Gerald W Lim, Michael WortisAbstract:Abstract We study the shapes of human red blood cells using continuum mechanics. In particular, we model the crenated, echinocytic shapes and show how they may arise from a competition between the bending energy of the plasma membrane and the stretching/shear elastic energies of the membrane skeleton. In contrast to earlier work, we calculate spicule shapes exactly by solving the equations of continuum mechanics subject to appropriate boundary conditions. A simple scaling analysis of this competition reveals an elastic length Λ el , which sets the length scale for the spicules and is, thus, related to the number of spicules experimentally observed on the fully developed Echinocyte.
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Echinocyte shapes bending stretching and shear determine spicule shape and spacing
arXiv: Soft Condensed Matter, 2001Co-Authors: Ranjan Mukhopadhyay, H Gerald W Lim, Michael WortisAbstract:We study the shapes of human red blood cells using continuum mechanics. In particular, we model the crenated, echinocytic shapes and show how they may arise from a competition between the bending energy of the plasma membrane and the stretching/shear elastic energies of the membrane skeleton. In contrast to earlier work, we calculate spicule shapes exactly by solving the equations of continuum mechanics subject to appropriate boundary conditions. A simple scaling analysis of this competition reveals an elastic length which sets the length scale for the spicules and is, thus, related to the number of spicules experimentally observed on the fully developed Echinocyte.
Emilie Sauret - One of the best experts on this subject based on the ideXlab platform.
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Deformation behaviour of stomatocyte, discocyte and Echinocyte red blood cell morphologies during optical tweezers stretching
Biomechanics and Modeling in Mechanobiology, 2020Co-Authors: Nadeeshani Maheshika Geekiyanage, Emilie Sauret, Suvash C. Saha, Robert L. Flower, Y. T. GuAbstract:The red blood cell (RBC) deformability is a critical aspect, and assessing the cell deformation characteristics is essential for better diagnostics of healthy and deteriorating RBCs. There is a need to explore the connection between the cell deformation characteristics, cell morphology, disease states, storage lesion and cell shape-transformation conditions for better diagnostics and treatments. A numerical approach inspired from the previous research for RBC morphology predictions and for analysis of RBC deformations is proposed for the first time, to investigate the deformation characteristics of different RBC morphologies. The present study investigates the deformability characteristics of stomatocyte, discocyte and Echinocyte morphologies during optical tweezers stretching and provides the opportunity to study the combined contribution of cytoskeletal spectrin network and the lipid-bilayer during RBC deformation. The proposed numerical approach predicts agreeable deformation characteristics of the healthy discocyte with the analogous experimental observations and is extended to further investigate the deformation characteristics of stomatocyte and Echinocyte morphologies. In particular, the computer simulations are performed to investigate the influence of direct stretching forces on different equilibrium cell morphologies on cell spectrin link extensions and cell elongation index, along with a parametric analysis on membrane shear modulus, spectrin link extensibility, bending modulus and RBC membrane–bead contact diameter. The results agree with the experimentally observed stiffer nature of stomatocyte and Echinocyte with respect to a healthy discocyte at experimentally determined membrane characteristics and suggest the preservation of relevant morphological characteristics, changes in spectrin link densities and the primary contribution of cytoskeletal spectrin network on deformation behaviour of stomatocyte, discocyte and Echinocyte morphologies during optical tweezers stretching deformation. The numerical approach presented here forms the foundation for investigations into deformation characteristics and recoverability of RBCs undergoing storage lesion.
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A coarse-grained red blood cell membrane model to study stomatocyte-discocyte-Echinocyte morphologies
PLOS ONE, 2019Co-Authors: Nadeeshani Maheshika Geekiyanage, Emilie Sauret, Suvash C. Saha, Robert L. Flower, Marie Anne Balanant, Chwee Teck LimAbstract:An improved red blood cell (RBC) membrane model is developed based on the bilayer coupling model (BCM) to accurately predict the complete sequence of stomatocyte-discocyte-Echinocyte (SDE) transformation of a RBC. The coarse-grained (CG)–RBC membrane model is proposed to predict the minimum energy configuration of the RBC from the competition between lipid-bilayer bending resistance and cytoskeletal shear resistance under given reference constraints. In addition to the conventional membrane surface area, cell volume and bilayer-leaflet-area-difference constraints, a new constraint: total-membrane-curvature is proposed in the model to better predict RBC shapes in agreement with experimental observations. A quantitative evaluation of several cellular measurements including length, thickness and shape factor, is performed for the first time, between CG-RBC model predicted and three-dimensional (3D) confocal microscopy imaging generated RBC shapes at equivalent reference constraints. The validated CG-RBC membrane model is then employed to investigate the effect of reduced cell volume and elastic length scale on SDE transformation, to evaluate the RBC deformability during SDE transformation, and to identify the most probable RBC cytoskeletal reference state. The CG-RBC membrane model can predict the SDE shape behaviour under diverse shape-transforming scenarios, in-vitro RBC storage, microvascular circulation and flow through microfluidic devices.
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Modelling the deformation behavior of stomatocyte, discocyte and Echinocyte red blood cell morphologies during optical tweezers stretching
2019Co-Authors: Nadeeshani Maheshika Geekiyanage, Emilie Sauret, Suvash C. Saha, Robert L. FlowerAbstract:A coarse-grained (CG) red blood cell (RBC) membrane model is used to investigate the deformation behavior of stomatocyte, discocyte and Echinocyte morphologies during optical tweezers stretching. First, the numerically predicted discocyte deformation behavior is validated against analogous experimental observations, and then the numerically predicted stomatocyte and Echinocyte deformation behavior is compared to the discocyte deformation behavior. The findings indicate that the CG-RBC membrane model is capable of accurately predicting the deformation behavior of stomatocyte, discocyte and Echinocyte RBC morphologies during optical tweezers stretching, and an applicable tool to investigate the evolution of RBC behavior and membrane properties for different morphologies.
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Shape Factor for CG-RBC membrane model predicted stomatocyte IV—Echinocyte IV RBC shapes.
2019Co-Authors: Nadeeshani Maheshika Geekiyanage, Emilie Sauret, Marie Anne Balanant, Suvash Saha, Robert Flower, Chwee Teck LimAbstract:Shape Factor for CG-RBC membrane model predicted stomatocyte IV—Echinocyte IV RBC shapes.
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CG-RBC membrane model predicted stomatocyte II, discocyte and Echinocyte II shapes at varying elastic length scale, = 0.11, 0.18, 0.25, 0.35 and 0.56. The coloured regions of the Echinocyte II shape represent the membrane curvature on its’ vertex po
2019Co-Authors: Nadeeshani Maheshika Geekiyanage, Emilie Sauret, Marie Anne Balanant, Suvash Saha, Robert Flower, Chwee Teck LimAbstract:CG-RBC membrane model predicted stomatocyte II, discocyte and Echinocyte II shapes at varying elastic length scale, = 0.11, 0.18, 0.25, 0.35 and 0.56. The coloured regions of the Echinocyte II shape represent the membrane curvature on its’ vertex points .