Blood cell aggregation and adhesion to endothelial cells under shear flow are crucial to many biological processes such as thrombi formation, inflammatory cascade, and tumor metastasis, in which these cellular interac...Blood cell aggregation and adhesion to endothelial cells under shear flow are crucial to many biological processes such as thrombi formation, inflammatory cascade, and tumor metastasis, in which these cellular interactions are mainly mediated by the underlying receptor-ligand bindings. While theoretical modeling of aggregation dynamics and adhesion kinetics of interacting cells have been well studied separately, how to couple these two processes remains unclear. Here we develop a combined model that couples cellular aggregation dynamics and adhesion kinetics under shear flow. The impacts of shear rate （or shear stress） and molecular binding affinity were elucidated. This study provides a unified model where the action of a fluid flow drives cell aggregation and adhesion under the modulations of the mechanical shear flow and receptor-ligand interaction kinetics. It offers an insight into understanding the relevant biological processes and functions.展开更多
The kinetics of solvent.extraction of aluminum with di-2-ethylhexyl phosphoric acid(DEHPA)in n-heptane have been studied in a constant interfacial area cell.A HC1-KHC8H404(potassium biphthalate.KHL)buffer solution was...The kinetics of solvent.extraction of aluminum with di-2-ethylhexyl phosphoric acid(DEHPA)in n-heptane have been studied in a constant interfacial area cell.A HC1-KHC8H404(potassium biphthalate.KHL)buffer solution was used to maintain a constant pH during extraction.The effects of the concentration of aluminum,pH,the concentration of the extractant,the interfacial area and the temperature on the extraction rate were investigated.A method has been invented to determine amont of the extracted aluminum in the organic phase with 8-hydroxyquinoline.Based on calculation of the coordination states of the aluminum ions and their contribution to the reaction rate,a raaction mechanism which includes two main reaction paths,has been proposed to describe the process.One path starts from Al(H_(2)O)6^(+).and the other starts from Al(H_(2)O)6^(+).The reaction could take place both in the aqueous phase and at the interface.The main reaction region could be changed as the conditions of extraction were changed.When[HA]<0.03 mol/L the process was controlled by the interfacial reaction,and when[HA]>0.03 mol/L it was shifted to a homogeneous aqueous solution reaction.展开更多
A single potential step chronoabsorptometric method for the determination of ki- netic parameters of simple quasi-reversible reactions is described.It is verified by determining the kinetic parameters for the electror...A single potential step chronoabsorptometric method for the determination of ki- netic parameters of simple quasi-reversible reactions is described.It is verified by determining the kinetic parameters for the electroreduction of ferricyanide.A long-optical-path electro- chemical cell with a plug-in electrode is used.The thickness of solution layer is 0.55 mm展开更多
基金supported by National Natural Science Foundation of China (grants 31230027, 31110103918 and 11172207)National Key Basic Research Foundation of China (grant 2011CB710904)Strategic Priority Research Program (grants XDA01030102 and XDA04020219)
文摘Blood cell aggregation and adhesion to endothelial cells under shear flow are crucial to many biological processes such as thrombi formation, inflammatory cascade, and tumor metastasis, in which these cellular interactions are mainly mediated by the underlying receptor-ligand bindings. While theoretical modeling of aggregation dynamics and adhesion kinetics of interacting cells have been well studied separately, how to couple these two processes remains unclear. Here we develop a combined model that couples cellular aggregation dynamics and adhesion kinetics under shear flow. The impacts of shear rate （or shear stress） and molecular binding affinity were elucidated. This study provides a unified model where the action of a fluid flow drives cell aggregation and adhesion under the modulations of the mechanical shear flow and receptor-ligand interaction kinetics. It offers an insight into understanding the relevant biological processes and functions.
基金supported by China National Natural Science Foundation。
文摘The kinetics of solvent.extraction of aluminum with di-2-ethylhexyl phosphoric acid(DEHPA)in n-heptane have been studied in a constant interfacial area cell.A HC1-KHC8H404(potassium biphthalate.KHL)buffer solution was used to maintain a constant pH during extraction.The effects of the concentration of aluminum,pH,the concentration of the extractant,the interfacial area and the temperature on the extraction rate were investigated.A method has been invented to determine amont of the extracted aluminum in the organic phase with 8-hydroxyquinoline.Based on calculation of the coordination states of the aluminum ions and their contribution to the reaction rate,a raaction mechanism which includes two main reaction paths,has been proposed to describe the process.One path starts from Al(H_(2)O)6^(+).and the other starts from Al(H_(2)O)6^(+).The reaction could take place both in the aqueous phase and at the interface.The main reaction region could be changed as the conditions of extraction were changed.When[HA]<0.03 mol/L the process was controlled by the interfacial reaction,and when[HA]>0.03 mol/L it was shifted to a homogeneous aqueous solution reaction.
文摘A single potential step chronoabsorptometric method for the determination of ki- netic parameters of simple quasi-reversible reactions is described.It is verified by determining the kinetic parameters for the electroreduction of ferricyanide.A long-optical-path electro- chemical cell with a plug-in electrode is used.The thickness of solution layer is 0.55 mm
