Background:It remains unclear whether the outcomes of ST-elevation myocardial infarction(STEMI)patients treated with primary percutaneous coronary intervention(PPCI)during off-hours are as favorable as those treated d...Background:It remains unclear whether the outcomes of ST-elevation myocardial infarction(STEMI)patients treated with primary percutaneous coronary intervention(PPCI)during off-hours are as favorable as those treated during on-hours,especially those with a first medical contact-to-device(FMC-to-device)time within 90 min.We aimed to determine whether off-hours admission impacted late outcomes in patients undergoing PPCI and with an FMC-to-device time<90 min.Methods:This multicenter retrospective study included 670 STEMI patients who underwent successful PPCI and had an FMC-to-device time<90 min from 19 chest pain centers in Beijing from January 2018 to December 2018.Patients were divided into on-hours group and off-hours group based on their arrival time.Baseline characteristics,clinical data,and key time intervals during treatment were collected from the Quality Control&Improvement Center of Cardiovascular Intervention of Beijing by the 4tHeart and Brain Green Channel”app.Results:Overall,the median age of the patients was 58.8 years and 19.9%(133/670)were female.Of these,296(44.2%)patients underwent PPCI during on-hours and 374(55.8%)patients underwent PPCI during off-hours.Compared with the on-hours group,the off-hours group had a longer FMC-to-device time and fewer patients with FMC-to-device time<60 min(P<0.05).During the mean follow-up period of 24 months,a total of 64(9.6%)participants experienced a major adverse cardiovascular event(MACE),with 28(9.1%)in the on-hours group and 36(9.6%)in the off-hours group(P>0.05).According to the Cox regression analyses,off-hours admission was not a predictor of 2-year MACEs(P=0.788).Similarly,the Kaplan-Meier curves showed that the risks of a MACE,all-cause death,reinfarction,and target vessel revascularization were not significantly different between the two groups(P>0.05).Conclusions:This real-world,multicenter retrospective study demonstrated that for STEMI patients who underwent PPCI within 90 min,off-hours admission was safe,with no difference in the risk of 2-year展开更多
在轨道交通中,接触式验电器用于接触网停电作业中检测接触网是否停电,以确保作业地线的正确操作和检修工作安全进行。接触电极作为接触式验电器的重要组成部分,直接影响验电信号的采集。为研究接触式验电器的接触电极结构对验电结果的影...在轨道交通中,接触式验电器用于接触网停电作业中检测接触网是否停电,以确保作业地线的正确操作和检修工作安全进行。接触电极作为接触式验电器的重要组成部分,直接影响验电信号的采集。为研究接触式验电器的接触电极结构对验电结果的影响,以GSY-II型27.5 k V交流验电器和ZGD型1 500 V直流验电器为例,分析了其工作原理,并仿真研究了接触电极形状和长度的改变对验电结果的影响。仿真结果表明:对于交流验电器,改变接触电极形状为圆钩型和V型,内部电路的感应信号电压分别变化了3.1%和2.3%,该变化对验电结果影响较小;增加接触电极长度会提高感应信号电压,从而提高验电灵敏度。对于直流验电器,其接触电极形状和长度改变后,内部电路的信号电压保持不变,因此接触电极的形状和长度不影响验电结果。仿真结果为设计和优化验电器结构提供了参考依据。展开更多
基金a grant from the National Natural Science Foundation of China(No.81670415).
文摘Background:It remains unclear whether the outcomes of ST-elevation myocardial infarction(STEMI)patients treated with primary percutaneous coronary intervention(PPCI)during off-hours are as favorable as those treated during on-hours,especially those with a first medical contact-to-device(FMC-to-device)time within 90 min.We aimed to determine whether off-hours admission impacted late outcomes in patients undergoing PPCI and with an FMC-to-device time<90 min.Methods:This multicenter retrospective study included 670 STEMI patients who underwent successful PPCI and had an FMC-to-device time<90 min from 19 chest pain centers in Beijing from January 2018 to December 2018.Patients were divided into on-hours group and off-hours group based on their arrival time.Baseline characteristics,clinical data,and key time intervals during treatment were collected from the Quality Control&Improvement Center of Cardiovascular Intervention of Beijing by the 4tHeart and Brain Green Channel”app.Results:Overall,the median age of the patients was 58.8 years and 19.9%(133/670)were female.Of these,296(44.2%)patients underwent PPCI during on-hours and 374(55.8%)patients underwent PPCI during off-hours.Compared with the on-hours group,the off-hours group had a longer FMC-to-device time and fewer patients with FMC-to-device time<60 min(P<0.05).During the mean follow-up period of 24 months,a total of 64(9.6%)participants experienced a major adverse cardiovascular event(MACE),with 28(9.1%)in the on-hours group and 36(9.6%)in the off-hours group(P>0.05).According to the Cox regression analyses,off-hours admission was not a predictor of 2-year MACEs(P=0.788).Similarly,the Kaplan-Meier curves showed that the risks of a MACE,all-cause death,reinfarction,and target vessel revascularization were not significantly different between the two groups(P>0.05).Conclusions:This real-world,multicenter retrospective study demonstrated that for STEMI patients who underwent PPCI within 90 min,off-hours admission was safe,with no difference in the risk of 2-year
文摘在轨道交通中,接触式验电器用于接触网停电作业中检测接触网是否停电,以确保作业地线的正确操作和检修工作安全进行。接触电极作为接触式验电器的重要组成部分,直接影响验电信号的采集。为研究接触式验电器的接触电极结构对验电结果的影响,以GSY-II型27.5 k V交流验电器和ZGD型1 500 V直流验电器为例,分析了其工作原理,并仿真研究了接触电极形状和长度的改变对验电结果的影响。仿真结果表明:对于交流验电器,改变接触电极形状为圆钩型和V型,内部电路的感应信号电压分别变化了3.1%和2.3%,该变化对验电结果影响较小;增加接触电极长度会提高感应信号电压,从而提高验电灵敏度。对于直流验电器,其接触电极形状和长度改变后,内部电路的信号电压保持不变,因此接触电极的形状和长度不影响验电结果。仿真结果为设计和优化验电器结构提供了参考依据。
