Objectives Endothelial senescence has been proposed to be involved in endothelial dysfunction and atherogenesis. This study investigates the effects of ginsenoside Rbl, a major constituent of ginseng,on H<sub>2&...Objectives Endothelial senescence has been proposed to be involved in endothelial dysfunction and atherogenesis. This study investigates the effects of ginsenoside Rbl, a major constituent of ginseng,on H<sub>2</sub>O<sub>2</sub>-induced endothelial senescence.Methods Primary human umbilical vein endothelial cells（HUVECs） senescence was induced by H<sub>2</sub>O<sub>2</sub> as judged by senescence-associated P-galactosidase assay （SA-P-gal）.Fntracellur superoxide dismutase（S0D1） activity and malondialdehyde（MDA） level were determined by commercial kit.S0D1 mRNA and protein expression were analyzed by real time PCR and Western blot.Reactive oxygen species（ROS） were determined by flow cytometry.Results Rb1 was found to reverse endothelial senescence,as witnessed by a significant decrease of senescent cell numbers. Rbl could markedly increase intracellular SOD activity, decrease the MDA level,and suppress the generation of intracellular ROS in H<sub>2</sub>O<sub>2</sub>-treated HUVECs.Consistent with these findings,Rbl can effectively restore SOD1 mRNA and protein expression which decreased in H<sub>2</sub>O<sub>2</sub> treated cells. Conclusions Our report demonstrates thatRbl can exert reversal effects on H<sub>2</sub>O<sub>2</sub>-induced cellular senescence through modulating cellular redox status.展开更多
Traveling wave differential protection has the ability,in theory,to entirely eliminate the effects of distributed capacitive current,but it cannot be applied on series-capacitor-compensated lines directly.In this pape...Traveling wave differential protection has the ability,in theory,to entirely eliminate the effects of distributed capacitive current,but it cannot be applied on series-capacitor-compensated lines directly.In this paper,unbalanced output of conventional forward and reverse traveling wave differential currents under normal operating conditions and external faults was analyzed.A new type of traveling wave differential current was defined by combining forward and reverse traveling wave differential currents.Expressions of the defined differential current when internal and external faults occur were deduced.On this basis,a new principle of traveling wave module differential protection on series-capacitor-compensated lines was proposed,and characteristics of module differential current under different faults were analyzed.The priniciple is immune to line distributed capacity,series capacitor positions,and presence or absence of MOV breakovers.The validity of this scheme was verified by PSACD simulations.展开更多
文摘Objectives Endothelial senescence has been proposed to be involved in endothelial dysfunction and atherogenesis. This study investigates the effects of ginsenoside Rbl, a major constituent of ginseng,on H<sub>2</sub>O<sub>2</sub>-induced endothelial senescence.Methods Primary human umbilical vein endothelial cells（HUVECs） senescence was induced by H<sub>2</sub>O<sub>2</sub> as judged by senescence-associated P-galactosidase assay （SA-P-gal）.Fntracellur superoxide dismutase（S0D1） activity and malondialdehyde（MDA） level were determined by commercial kit.S0D1 mRNA and protein expression were analyzed by real time PCR and Western blot.Reactive oxygen species（ROS） were determined by flow cytometry.Results Rb1 was found to reverse endothelial senescence,as witnessed by a significant decrease of senescent cell numbers. Rbl could markedly increase intracellular SOD activity, decrease the MDA level,and suppress the generation of intracellular ROS in H<sub>2</sub>O<sub>2</sub>-treated HUVECs.Consistent with these findings,Rbl can effectively restore SOD1 mRNA and protein expression which decreased in H<sub>2</sub>O<sub>2</sub> treated cells. Conclusions Our report demonstrates thatRbl can exert reversal effects on H<sub>2</sub>O<sub>2</sub>-induced cellular senescence through modulating cellular redox status.
文摘Traveling wave differential protection has the ability,in theory,to entirely eliminate the effects of distributed capacitive current,but it cannot be applied on series-capacitor-compensated lines directly.In this paper,unbalanced output of conventional forward and reverse traveling wave differential currents under normal operating conditions and external faults was analyzed.A new type of traveling wave differential current was defined by combining forward and reverse traveling wave differential currents.Expressions of the defined differential current when internal and external faults occur were deduced.On this basis,a new principle of traveling wave module differential protection on series-capacitor-compensated lines was proposed,and characteristics of module differential current under different faults were analyzed.The priniciple is immune to line distributed capacity,series capacitor positions,and presence or absence of MOV breakovers.The validity of this scheme was verified by PSACD simulations.
