19 research outputs found

    Modelling of platelet–fibrin clot formation in flow with a DPD–PDE method

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    International audienceThe paper is devoted to mathematical modelling of clot growth in bloodflow. Great complexity of the hemostatic system dictates the need of usage of themathematical models to understand its functioning in the normal and especially inpathological situations. In this work we investigate the interaction of blood flow,platelet aggregation and plasma coagulation. We develop a hybrid DPD–PDE modelwhere dissipative particle dynamics (DPD) is used to model plasma flow and platelets,while the regulatory network of plasma coagulation is described by a system of partialdifferential equations. Modelling results confirm the potency of the scenario of clotgrowth where at the first stage of clot formation platelets form an aggregate due toweak inter-platelet connections and then due to their activation. This enables the formationof the fibrin net in the centre of the platelet aggregate where the flow velocity issignificantly reduced. The fibrin net reinforces the clot and allows its further growth.When the clot becomes sufficiently large, it stops growing due to the narrowed vesseland the increase of flow shear rate at the surface of the clot. Its outer part is detachedby the flow revealing the inner part covered by fibrin. This fibrin cap does not allownew platelets to attach at the high shear rate, and the clot stops growing. Dependenceof the final clot size on wall shear rate and on other parameters is studied

    Mathematical Modeling of Thrombin Generation and Wave Propagation: From Simple to Complex Models and Backwards

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    Synthesis of spin crossover nano-objects with different morphologies and properties

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    Imidazolium camphorsulfonamides: Chiral catanionic liquid crystals with tunable thermal properties

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    International audienceWe report the synthesis of novel chiral catanionic liquid crystals bearing camphorsulfonamide substructures. The phase behaviour of these long-chain substituted imidazolium sulphates and sulfonates was investigated using X-ray diffraction (XRD), polarizing optical microscopy (POM) and differential scanning calorimetry (DSC). We observed that the phase behaviour clearly depends on the substitution of both cation and anion. The chiral camphorsulfonamide substructures have an unfavourable influence on the formation of liquid crystalline (LC-) phases. Contrary to N,N0-di-alkyl-imidazolium salts, the formation of LC phases was only observed when both cation and anion are substituted with long alkyl chains (C12 or C16). Furthermore, the phase transition temperatures depend on the chain length of the alkyl groups, as higher phase transition temperatures were observed for compounds bearing longer alkyl chains. However, no macroscopic evidence for the formation of chiral mesophases was obtained

    Toward Organization of Cyano-Bridged Coordination Polymer Nanoparticles within an Ionic Liquid Crystal

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    International audienceSize controlled cyano-bridged coordination polymer nanoparticles Mn1.5[Cr(CN)6] have been synthesized and organized at the nanolevel by using the room temperature ionic liquid crystal (ILC) C12-MIMBF4. The as-obtained material was studied by transmission electron microscopy (TEM), differential scanning calorimetry (DSC), optical microscopy, and X-ray diffraction. These analyses reveal the presence of a long-range organization of cyano-bridged nanoparticles at the nanoscale level within the ILC phase. The magnetic study of these nanoparticles reveals an appearance of a nanocluster-glass-like regime caused by magnetostatic interactions between neighboring nanoparticles. The properties of these organized nanoparticles have been compared with the properties of nanoparticles of the same composition and stoichiometry obtained and randomly dispersed into the isotropic IL C10-MIMBF4
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