近几年来,左心室舒张功能异常在产生心脏病症状和体征方面的重要性越来越受到重视。研究表明,临床上部分心力衰竭不是因为收缩功能异常,而是由于舒张功能异常所致。鉴于两者的处理不同,对其鉴别就显得非常重要。舒张功能的估测通常包含...近几年来,左心室舒张功能异常在产生心脏病症状和体征方面的重要性越来越受到重视。研究表明,临床上部分心力衰竭不是因为收缩功能异常,而是由于舒张功能异常所致。鉴于两者的处理不同,对其鉴别就显得非常重要。舒张功能的估测通常包含3方面的内容:1.心室松驰:由等容松驰指数如-dp/dt和 T 表示,2.心腔硬度:即相对于心腔容量改变所发生的压力改变(dp/dv),该比值的倒数即为心腔顺应性,3.心肌硬度:代表当心肌承受一个拉力时对心肌伸展的一种阻力。展开更多
The dioecious plant,Hippophae rhamnoides,is a pioneer species in community succession on the Qinghai-Tibet Plateau(QTP),plays great roles in various ecosystem services.However,the males and females of the species diff...The dioecious plant,Hippophae rhamnoides,is a pioneer species in community succession on the Qinghai-Tibet Plateau(QTP),plays great roles in various ecosystem services.However,the males and females of the species differ both in their morphology and physiology,resulting in a change in the ratio of male to female plants depending on the environment.To further explore the functional traits critical to this sex-based distinctive response in the alpine grassland,we have surveyed the sex ratios,measured their photosynthetic parameters,height,leaf area and biomass allocation.The results showed that(i)The males had higher Pn,light saturation point,apparent quantum efficiency,A_(max) and lower water-use efficiency(WUE),which exhibited higher utilization efficiency or tolerance to strong light,while the females indicated higher utilization efficiency for low light and water.And it showed sex-specific biomass allocation patterns.(ii)H.rhamnoides populations across the successional stages all showed a male-biased sexual allocation,which was closely related to sex-specific WUE,Pn,root biomass/total biomass and root-crown ratio.(iii)The leaf traits of H.rhamnoides changed from higher N_(area),P_(area) and leaf mass per area in the early and late to lower in the middle,which meant they moved their growth strategy from resource rapid acquisition to conservation as the succession progressed.(iv)The increasing soil total phosphorus mostly contributed to regulating the sex bias of populations and variations of traits during the succession.The results are vital for the management of grassland degradation and restoration due to shrub encroachment on the QTP.展开更多
文摘近几年来,左心室舒张功能异常在产生心脏病症状和体征方面的重要性越来越受到重视。研究表明,临床上部分心力衰竭不是因为收缩功能异常,而是由于舒张功能异常所致。鉴于两者的处理不同,对其鉴别就显得非常重要。舒张功能的估测通常包含3方面的内容:1.心室松驰:由等容松驰指数如-dp/dt和 T 表示,2.心腔硬度:即相对于心腔容量改变所发生的压力改变(dp/dv),该比值的倒数即为心腔顺应性,3.心肌硬度:代表当心肌承受一个拉力时对心肌伸展的一种阻力。
基金supported by National Natural Science Foundation of China(32201525)the Gansu province’s Key Research and Development Plan(21YF5NA069)+2 种基金the Longyuan Talent Youth Innovation and Entrepreneurship Team projectthe Key Laboratory of Eco-functional Polymer Materials of the Ministry of Education(YDZX20216200001007)the Foreign Expert Introduction Special Project of Gansu Province(22JR10KA010).
文摘The dioecious plant,Hippophae rhamnoides,is a pioneer species in community succession on the Qinghai-Tibet Plateau(QTP),plays great roles in various ecosystem services.However,the males and females of the species differ both in their morphology and physiology,resulting in a change in the ratio of male to female plants depending on the environment.To further explore the functional traits critical to this sex-based distinctive response in the alpine grassland,we have surveyed the sex ratios,measured their photosynthetic parameters,height,leaf area and biomass allocation.The results showed that(i)The males had higher Pn,light saturation point,apparent quantum efficiency,A_(max) and lower water-use efficiency(WUE),which exhibited higher utilization efficiency or tolerance to strong light,while the females indicated higher utilization efficiency for low light and water.And it showed sex-specific biomass allocation patterns.(ii)H.rhamnoides populations across the successional stages all showed a male-biased sexual allocation,which was closely related to sex-specific WUE,Pn,root biomass/total biomass and root-crown ratio.(iii)The leaf traits of H.rhamnoides changed from higher N_(area),P_(area) and leaf mass per area in the early and late to lower in the middle,which meant they moved their growth strategy from resource rapid acquisition to conservation as the succession progressed.(iv)The increasing soil total phosphorus mostly contributed to regulating the sex bias of populations and variations of traits during the succession.The results are vital for the management of grassland degradation and restoration due to shrub encroachment on the QTP.
