Aim Evidence has shown that stimulation of alA-adrenorecetors receptor （alA-AR） or angiotensin II type 1 receptor （AT1R） acutely down-regulates the rapid component of the delayed rectifier K ＋ current （IKr） via...Aim Evidence has shown that stimulation of alA-adrenorecetors receptor （alA-AR） or angiotensin II type 1 receptor （AT1R） acutely down-regulates the rapid component of the delayed rectifier K ＋ current （IKr） via protein kinase C （PKC）. This study was designed to investigate which PKC isozymes mediate down-regulations of IKr by alA-AR and AT1R. Method The whole-cell patch-clamp technique was used to record IKr in native cardio- myocytes and in human embryonic kidney （HEK） 293 cells co-transfected with human ether-a-go-go related gene （hERG） encoding α-subunit of IKr and human alA-AR or AT1R gene. Result In isolated guinea-pig ventricular cardiomyocytes the inhibitory action of Ang II on IKr was little affected by Go6976 （selectively inhibiting PKCα, β and γ） and Go6983 （selectively inhibiting PKCα, β, γ , δ, and ζ）, but was significantly antagonized by an inter- nal dialysis with PKCe-selective inhibitory peptide εV1 -2. In contrast, the inhibitory action of alA-AR agonist A61603 on IKr was remarkably attenuated by Go6976 or Go6983, but not affected by peptide εV1 -2. Moreover, specific PKC-selective inhibitory peptide antagonized the effect of A61603. The results suggested that PKCe and PKCα isoform respectively mediated the inhibitory effect of AT1R and a1A-AR. In heterologous expression system, both PKCα and e-selective activator peptides down regulated hERG current with different manner. PKCα activator peptide shifted the activation curve of the channel to the right, but PKCe-selective activator peptide did not. Simi- larly, A61603 shifted the activation curve to the right, whereas Ang Ⅱ had no effect. In addition, both A61603 and PKCα activator peptide showed inhibitory action on bERG A PKC current （an bERG mutant in which 17 of the 18 ROSITE-predicted PKC acceptor serines/threonines were changed to alanine） with a similar potency to wild type bERG current. But, both Ang Ⅱ and PKCe-selective activator peptide exhibited no effects on bERG △ PKC cur- rent. The results indicated that PKCα and PKCe isoforms down-regulated bERG current through different mecha- nism. Conclusion PKCα and PKCe isoform respectively mediates the inhibition on IKr by stimulation of AT1R and alA-AR via different molecular mechanism.展开更多
Rectifying circuit,as a crucial component for converting alternating current into direct current,plays a pivotal role in energy harvesting microsystems.Traditional silicon-based or germanium-based rectifier diodes hin...Rectifying circuit,as a crucial component for converting alternating current into direct current,plays a pivotal role in energy harvesting microsystems.Traditional silicon-based or germanium-based rectifier diodes hinder system integration due to their specific manufacturing processes.Conversely,metal oxide diodes,with their simple fabrication techniques,offer advantages for system integration.The oxygen vacancy defect of oxide semiconductor will greatly affect the electrical performance of the device,so the performance of the diode can be effectively controlled by adjusting the oxygen vacancy concentration.This study centers on optimizing the performance of diodes by modulating the oxygen vacancy concentration within InGaZnO films through control of oxygen flows during the sputtering process.Experimental results demonstrate that the diode exhibits a forward current density of 43.82 A·cm^(−2),with a rectification ratio of 6.94×10^(4),efficiently rectifying input sine signals with 1 kHz frequency and 5 V magnitude.These results demonstrate its potential in energy conversion and management.By adjusting the oxygen vacancy,a methodology is provided for optimizing the performance of rectifying diodes.展开更多
The group of peasant laborer, being a beneficial group in present Chinese society, has already come into being, which is both outcome of duality and the important strength breaking duality in Chinese society. However,...The group of peasant laborer, being a beneficial group in present Chinese society, has already come into being, which is both outcome of duality and the important strength breaking duality in Chinese society. However, for a long time the severe maladjustments of peasant laborer group＇s not only engender the injustice of their position but also do harm to the development of social structure and economic growth in China. Therefore, describing the position of peasant laborer group and analyzing the consequence which causes by their imbalance position may have significant impact on perfecting Chinese social structure and attaining the objectives of combining the city with countryside in theory and practice.展开更多
文摘Aim Evidence has shown that stimulation of alA-adrenorecetors receptor （alA-AR） or angiotensin II type 1 receptor （AT1R） acutely down-regulates the rapid component of the delayed rectifier K ＋ current （IKr） via protein kinase C （PKC）. This study was designed to investigate which PKC isozymes mediate down-regulations of IKr by alA-AR and AT1R. Method The whole-cell patch-clamp technique was used to record IKr in native cardio- myocytes and in human embryonic kidney （HEK） 293 cells co-transfected with human ether-a-go-go related gene （hERG） encoding α-subunit of IKr and human alA-AR or AT1R gene. Result In isolated guinea-pig ventricular cardiomyocytes the inhibitory action of Ang II on IKr was little affected by Go6976 （selectively inhibiting PKCα, β and γ） and Go6983 （selectively inhibiting PKCα, β, γ , δ, and ζ）, but was significantly antagonized by an inter- nal dialysis with PKCe-selective inhibitory peptide εV1 -2. In contrast, the inhibitory action of alA-AR agonist A61603 on IKr was remarkably attenuated by Go6976 or Go6983, but not affected by peptide εV1 -2. Moreover, specific PKC-selective inhibitory peptide antagonized the effect of A61603. The results suggested that PKCe and PKCα isoform respectively mediated the inhibitory effect of AT1R and a1A-AR. In heterologous expression system, both PKCα and e-selective activator peptides down regulated hERG current with different manner. PKCα activator peptide shifted the activation curve of the channel to the right, but PKCe-selective activator peptide did not. Simi- larly, A61603 shifted the activation curve to the right, whereas Ang Ⅱ had no effect. In addition, both A61603 and PKCα activator peptide showed inhibitory action on bERG A PKC current （an bERG mutant in which 17 of the 18 ROSITE-predicted PKC acceptor serines/threonines were changed to alanine） with a similar potency to wild type bERG current. But, both Ang Ⅱ and PKCe-selective activator peptide exhibited no effects on bERG △ PKC cur- rent. The results indicated that PKCα and PKCe isoforms down-regulated bERG current through different mecha- nism. Conclusion PKCα and PKCe isoform respectively mediates the inhibition on IKr by stimulation of AT1R and alA-AR via different molecular mechanism.
文摘Rectifying circuit,as a crucial component for converting alternating current into direct current,plays a pivotal role in energy harvesting microsystems.Traditional silicon-based or germanium-based rectifier diodes hinder system integration due to their specific manufacturing processes.Conversely,metal oxide diodes,with their simple fabrication techniques,offer advantages for system integration.The oxygen vacancy defect of oxide semiconductor will greatly affect the electrical performance of the device,so the performance of the diode can be effectively controlled by adjusting the oxygen vacancy concentration.This study centers on optimizing the performance of diodes by modulating the oxygen vacancy concentration within InGaZnO films through control of oxygen flows during the sputtering process.Experimental results demonstrate that the diode exhibits a forward current density of 43.82 A·cm^(−2),with a rectification ratio of 6.94×10^(4),efficiently rectifying input sine signals with 1 kHz frequency and 5 V magnitude.These results demonstrate its potential in energy conversion and management.By adjusting the oxygen vacancy,a methodology is provided for optimizing the performance of rectifying diodes.
基金Social Sciences Fund of Heilongjiang Province(06B002)
文摘The group of peasant laborer, being a beneficial group in present Chinese society, has already come into being, which is both outcome of duality and the important strength breaking duality in Chinese society. However, for a long time the severe maladjustments of peasant laborer group＇s not only engender the injustice of their position but also do harm to the development of social structure and economic growth in China. Therefore, describing the position of peasant laborer group and analyzing the consequence which causes by their imbalance position may have significant impact on perfecting Chinese social structure and attaining the objectives of combining the city with countryside in theory and practice.
