Flow boiling in open microchannels offers highly efficient heat transfer performance and has attracted increasing attention in the fields of heat transfer and thermalmanagement of electronic devices in recent years.Ho...Flow boiling in open microchannels offers highly efficient heat transfer performance and has attracted increasing attention in the fields of heat transfer and thermalmanagement of electronic devices in recent years.However,the continuous rise in power density of electronic components imposesmore stringent requirements on the heat transfer capability of microchannel flow boiling.HFE-7100,a dielectric coolant with favorable thermophysical properties,has become a focal point of research for enhancing flow boiling performance in open microchannels.The flow boiling heat transfer performance ofHFE-7100 was investigated in this study by fabricating micro-nano composite structures on the bottom surface of open microchannels using laser ablation technology.Based on visualization results,a comparative analysis was conducted on the bubble dynamics and flow pattern characteristics of HFE-7100 flow boiling in micronano structured open microchannels(MNSOMC)and smooth-surface open microchannels(SSOMC),to elucidate the enhancement mechanism of micro-nano structures on flow boiling heat transfer in open microchannels.The results indicate that the surface structures and strong wettability of MNSOMC accelerated bubble nucleation and departure.Moreover,bubbles in the channel tended to coalesce along the flow direction,forming elongated slug bubbles with high aspect ratios,which enabled efficient thin film evaporation in conjunction with intense nucleate boiling,thereby significantly enhancing flow boiling heat transfer.Under the experimental conditions of this study,the maximum enhancements in the heat transfer coefficient(HTC)and critical heat flux(CHF)of HFE-7100 inMNSOMC were 33.4%and 133.1%,respectively,with the CHF reaching up to 1542.3 kW⋅m^(−2).Furthermore,due to the superior wettability and capillary wicking capability of the micro-nano composite structures,the significant enhancement in flow boiling heat transfer was achieved without incurring a noticeable pressure drop penalty.展开更多
Heart rate variability(HRV)is an important marker for assessing the balance of the autonomic nervous system and clinical prognosis,because it can be non-invasively and easily measured,and the results are accurate and ...Heart rate variability(HRV)is an important marker for assessing the balance of the autonomic nervous system and clinical prognosis,because it can be non-invasively and easily measured,and the results are accurate and valuable.HRV is widely applied in cardiovascular disease fields.Exercise training is an important part of cardiac rehabilitation.Personalized sports rehabilitation therapy can effectively prevent the emergence of cardiovascular diseases,decrease the risk of recurrent cardiovascular events,and ameliorate dysfunction,as well as limitations in life,work,and social participation,caused by adverse cardiovascular events.However,sports rehabilitation can have drawbacks,in that improper training can cause injury,excessive fatigue,or even harmful cardiovascular events.To support future applica-tions,this article reviews recent applications of HRV in sports rehabilitation for cardiovascular diseases.展开更多
Background/aim:This study was aimed at evaluating 5-year effectiveness and safety in participants after XIENCE PRIME Everolimus Elution Coronary Stent System(EECSS)implantation.Materials and methods:From December 2013...Background/aim:This study was aimed at evaluating 5-year effectiveness and safety in participants after XIENCE PRIME Everolimus Elution Coronary Stent System(EECSS)implantation.Materials and methods:From December 2013 to May 2014,108 patients(127 lesions)were treated with the XIENCE PRIME EECSS.The entire follow-up included annual assessments for 5 years after treatment or until one of the clinical endpoints was reached.We evaluated the 5-year clinical outcomes with Kaplan-Meier analysis and the Cox regression model.Results:Nearly three-quarters of the participants were men(76.8%),and the average age was 65.6±10.8 years.Bifurcation lesions accounted for 96.1%(122 lesions),and left main lesions accounted for 3.9%(five lesions),with a total count of 127 lesions.The cumulative rate of major adverse cardiac events was as follows:1 year,1.9%;2 year,4.0%;and 5 year,10.0%.No definite or probable stent thrombosis was observed,and the rate of target lesion failure was only 3.3%over 5 years.The cumulative rate of major bleeding eventually increased to only 4.4%.Conclusions:The 5-year clinical outcomes were favorable in patients treated with XIENCE PRIME EECSS,and the incidence of stent thrombosis and target lesion failure was relatively low.The incidence of major bleeding gradually increased but remained moderate.展开更多
Lockdown and re-opening may become cyclical due to the recurrent waves of the COVID-19 epidemic.Few studies have examined temporal trends and determinants of in-hospital mortality among patients with ST-segment elevat...Lockdown and re-opening may become cyclical due to the recurrent waves of the COVID-19 epidemic.Few studies have examined temporal trends and determinants of in-hospital mortality among patients with ST-segment elevation myocardial infarction(STEMI),a life-threatening condition that requires emergency medical care.Using nation-wide data before,during and after the Wuhan lockdown,we aimed to depict temporal patterns and major determinants of STEMI in-hospital mortality in China across five time periods of the COVID-19 epidemic.We analyzed the data of 283,661 STEMI patients who were admitted to 4,487 chest-pain-centers across China,from January 1,2019 to May 31,2020.Compared with the period before the lockdown,STEMI in-hospital mortality increased by 25%(OR 1.25,95%CI 1.16–1.34)during Early Lockdown,by 12%(OR 1.12,95%CI 1.03–1.22)during Later Lockdown,by 35%(OR 1.35,95%CI 1.21–1.50)during Early Lift,and returned to pre-COVID risk(OR 1.04,95%CI 0.95–1.14)during Later Lift.For each time-period,we observed a clear mortality gradient by timing and types of revascularization procedure.In conclusion,the COVID-19 epidemic had a significant adverse impact on STEMI in-hospital mortality,with bimodal peaks during early lockdown and early lift periods and clear mortality gradients by timing and types of revascularization procedure,independent of the time periods.展开更多
基金funded by the National Natural Science Foundation of China(Grant No.52276047)the Open Fund of NationalKey Laboratory of SpacecraftThermal Control(Grant No.NKLST-JJ-202401011)the Beijing Municipal Science&Technology Commission(Grant No.Z231100006123010).
文摘Flow boiling in open microchannels offers highly efficient heat transfer performance and has attracted increasing attention in the fields of heat transfer and thermalmanagement of electronic devices in recent years.However,the continuous rise in power density of electronic components imposesmore stringent requirements on the heat transfer capability of microchannel flow boiling.HFE-7100,a dielectric coolant with favorable thermophysical properties,has become a focal point of research for enhancing flow boiling performance in open microchannels.The flow boiling heat transfer performance ofHFE-7100 was investigated in this study by fabricating micro-nano composite structures on the bottom surface of open microchannels using laser ablation technology.Based on visualization results,a comparative analysis was conducted on the bubble dynamics and flow pattern characteristics of HFE-7100 flow boiling in micronano structured open microchannels(MNSOMC)and smooth-surface open microchannels(SSOMC),to elucidate the enhancement mechanism of micro-nano structures on flow boiling heat transfer in open microchannels.The results indicate that the surface structures and strong wettability of MNSOMC accelerated bubble nucleation and departure.Moreover,bubbles in the channel tended to coalesce along the flow direction,forming elongated slug bubbles with high aspect ratios,which enabled efficient thin film evaporation in conjunction with intense nucleate boiling,thereby significantly enhancing flow boiling heat transfer.Under the experimental conditions of this study,the maximum enhancements in the heat transfer coefficient(HTC)and critical heat flux(CHF)of HFE-7100 inMNSOMC were 33.4%and 133.1%,respectively,with the CHF reaching up to 1542.3 kW⋅m^(−2).Furthermore,due to the superior wettability and capillary wicking capability of the micro-nano composite structures,the significant enhancement in flow boiling heat transfer was achieved without incurring a noticeable pressure drop penalty.
基金The research was financially supported by the Science and Technology Commission of Shanghai Municipality(Grant No.20dz1207200).
文摘Heart rate variability(HRV)is an important marker for assessing the balance of the autonomic nervous system and clinical prognosis,because it can be non-invasively and easily measured,and the results are accurate and valuable.HRV is widely applied in cardiovascular disease fields.Exercise training is an important part of cardiac rehabilitation.Personalized sports rehabilitation therapy can effectively prevent the emergence of cardiovascular diseases,decrease the risk of recurrent cardiovascular events,and ameliorate dysfunction,as well as limitations in life,work,and social participation,caused by adverse cardiovascular events.However,sports rehabilitation can have drawbacks,in that improper training can cause injury,excessive fatigue,or even harmful cardiovascular events.To support future applica-tions,this article reviews recent applications of HRV in sports rehabilitation for cardiovascular diseases.
基金This study was supported by grants from Clinical Research Plan of SHDC(SHDC2020CR1040B).
文摘Background/aim:This study was aimed at evaluating 5-year effectiveness and safety in participants after XIENCE PRIME Everolimus Elution Coronary Stent System(EECSS)implantation.Materials and methods:From December 2013 to May 2014,108 patients(127 lesions)were treated with the XIENCE PRIME EECSS.The entire follow-up included annual assessments for 5 years after treatment or until one of the clinical endpoints was reached.We evaluated the 5-year clinical outcomes with Kaplan-Meier analysis and the Cox regression model.Results:Nearly three-quarters of the participants were men(76.8%),and the average age was 65.6±10.8 years.Bifurcation lesions accounted for 96.1%(122 lesions),and left main lesions accounted for 3.9%(five lesions),with a total count of 127 lesions.The cumulative rate of major adverse cardiac events was as follows:1 year,1.9%;2 year,4.0%;and 5 year,10.0%.No definite or probable stent thrombosis was observed,and the rate of target lesion failure was only 3.3%over 5 years.The cumulative rate of major bleeding eventually increased to only 4.4%.Conclusions:The 5-year clinical outcomes were favorable in patients treated with XIENCE PRIME EECSS,and the incidence of stent thrombosis and target lesion failure was relatively low.The incidence of major bleeding gradually increased but remained moderate.
文摘Lockdown and re-opening may become cyclical due to the recurrent waves of the COVID-19 epidemic.Few studies have examined temporal trends and determinants of in-hospital mortality among patients with ST-segment elevation myocardial infarction(STEMI),a life-threatening condition that requires emergency medical care.Using nation-wide data before,during and after the Wuhan lockdown,we aimed to depict temporal patterns and major determinants of STEMI in-hospital mortality in China across five time periods of the COVID-19 epidemic.We analyzed the data of 283,661 STEMI patients who were admitted to 4,487 chest-pain-centers across China,from January 1,2019 to May 31,2020.Compared with the period before the lockdown,STEMI in-hospital mortality increased by 25%(OR 1.25,95%CI 1.16–1.34)during Early Lockdown,by 12%(OR 1.12,95%CI 1.03–1.22)during Later Lockdown,by 35%(OR 1.35,95%CI 1.21–1.50)during Early Lift,and returned to pre-COVID risk(OR 1.04,95%CI 0.95–1.14)during Later Lift.For each time-period,we observed a clear mortality gradient by timing and types of revascularization procedure.In conclusion,the COVID-19 epidemic had a significant adverse impact on STEMI in-hospital mortality,with bimodal peaks during early lockdown and early lift periods and clear mortality gradients by timing and types of revascularization procedure,independent of the time periods.
