Through research on the application of hydroviscous speed-adjusting clutch in belt conveyor, this paper concluded that hydroviscous speed-adjusting clutch has many advantages such as controllable start and stop, overl...Through research on the application of hydroviscous speed-adjusting clutch in belt conveyor, this paper concluded that hydroviscous speed-adjusting clutch has many advantages such as controllable start and stop, overload protection and multi-motor power equilibrium. But its theory when used in large power fan and pump could not meet the needs of belt conveyor soft-start operation. Focusing on the theo- retical analysis of the lubrication oil flow needed by the transmission procedure to form the oil-film. Put forward concrete calculation methods of lubrication flow and how to de- cide number of oil-films used in belt conveyor.展开更多
This paper aims to the research of the impact of fluid shear stress on the adhesion between vascular endothelial cells and leukocyte induced by tumor necrosis factor-α(TNF-α) by microfliudic chip technology.Microflu...This paper aims to the research of the impact of fluid shear stress on the adhesion between vascular endothelial cells and leukocyte induced by tumor necrosis factor-α(TNF-α) by microfliudic chip technology.Microfluidic chip was fabricated by soft lithograph; Endothelial microfluidic chip was constructed by optimizing types of the extracellular matrix proteins modified in the microchannel and cell incubation time;human umbilical vein endothelial cells EA.Hy926 lined in the microchannel were exposed to fluid shear stress of 1.68 dynes/cm^2 and 8.4 dynes/cm^2 respectively.Meanwhile,adhesion between EA.Hy926 cells and leukocyte was induced by TNF-αunder a flow condition.EA.Hy926 cell cultured in the static condition was used as control group.The numbers of fluorescently-labeled leukocyte in microchannel were counted to quantize the adhesion level between EA.Hy926 cells and leukocyte; cell immunofluorescence technique was used to detect the intercellular adhesion molecule(ICAM-1) expression.The constructed endothelial microfluidic chip can afford to the fluid shear stress and respond to exogenous stimulus of TNF-α; compared with the adhesion numbers of leukocyte in control group,adhesion between EA.Hy926 cells exposed to low fluid shear stress and leukocyte was reduced under the stimulus of TNF-α at a concentration of 10 ng/ml(P<0.05); leukocyte adhesion with EA.Hy926 cells exposed to high fluid shear stress was reduced significantly than EA.Hy926 cells in control group and EA.1Hy926 cells exposed to low fluid shear stress(P<0.01); the regulation mechanism of fluid shear stress to the adhesion between EA.Hy926 cells and leukocyte induced by TNF-αwas through the way of ICAM-1.The endothelial microfluidic chip fabricated in this paper could be used to study the functions of endothelial cell in vitro and provide a new technical platform for exploring the pathophysiology of the related cardiovascular system diseases under a flow environment.展开更多
文摘Through research on the application of hydroviscous speed-adjusting clutch in belt conveyor, this paper concluded that hydroviscous speed-adjusting clutch has many advantages such as controllable start and stop, overload protection and multi-motor power equilibrium. But its theory when used in large power fan and pump could not meet the needs of belt conveyor soft-start operation. Focusing on the theo- retical analysis of the lubrication oil flow needed by the transmission procedure to form the oil-film. Put forward concrete calculation methods of lubrication flow and how to de- cide number of oil-films used in belt conveyor.
文摘This paper aims to the research of the impact of fluid shear stress on the adhesion between vascular endothelial cells and leukocyte induced by tumor necrosis factor-α(TNF-α) by microfliudic chip technology.Microfluidic chip was fabricated by soft lithograph; Endothelial microfluidic chip was constructed by optimizing types of the extracellular matrix proteins modified in the microchannel and cell incubation time;human umbilical vein endothelial cells EA.Hy926 lined in the microchannel were exposed to fluid shear stress of 1.68 dynes/cm^2 and 8.4 dynes/cm^2 respectively.Meanwhile,adhesion between EA.Hy926 cells and leukocyte was induced by TNF-αunder a flow condition.EA.Hy926 cell cultured in the static condition was used as control group.The numbers of fluorescently-labeled leukocyte in microchannel were counted to quantize the adhesion level between EA.Hy926 cells and leukocyte; cell immunofluorescence technique was used to detect the intercellular adhesion molecule(ICAM-1) expression.The constructed endothelial microfluidic chip can afford to the fluid shear stress and respond to exogenous stimulus of TNF-α; compared with the adhesion numbers of leukocyte in control group,adhesion between EA.Hy926 cells exposed to low fluid shear stress and leukocyte was reduced under the stimulus of TNF-α at a concentration of 10 ng/ml(P<0.05); leukocyte adhesion with EA.Hy926 cells exposed to high fluid shear stress was reduced significantly than EA.Hy926 cells in control group and EA.1Hy926 cells exposed to low fluid shear stress(P<0.01); the regulation mechanism of fluid shear stress to the adhesion between EA.Hy926 cells and leukocyte induced by TNF-αwas through the way of ICAM-1.The endothelial microfluidic chip fabricated in this paper could be used to study the functions of endothelial cell in vitro and provide a new technical platform for exploring the pathophysiology of the related cardiovascular system diseases under a flow environment.
