目的:探讨冠心病患者介入术前血小板体积分布宽度(platelet distribution width,PDW)与预后的相关性。方法:采用回顾性研究的方法,收集2014年10月至2020年10月期间在首都医科大学附属北京安贞医院住院治疗的PCI患者13090例,所有患者均...目的:探讨冠心病患者介入术前血小板体积分布宽度(platelet distribution width,PDW)与预后的相关性。方法:采用回顾性研究的方法,收集2014年10月至2020年10月期间在首都医科大学附属北京安贞医院住院治疗的PCI患者13090例,所有患者均于我院术前完善静脉血常规检测,该项检测中包括PDW。将上述所有PCI患者基于PDW数值四等分分组,第一组(PDW≤11.6%)3286例,第二组(11.6%<PDW≤13.3%)3281例,第三组(13.3%<PDW≤17.4%)3280例,第四组(PDW>17.4%)3243例。收集患者资料并进行随访,记录主要的心脑血管不良事件(major adverse cardiovascular and cerebrovascular events,MACCE)及死亡。采用多因素矫正混杂因素的Cox回归分析,研究术前PDW对PCI患者预后的影响。结果:不同PDW组间年龄、陈旧性心肌梗死、心房颤动等,差异均有统计学意义(P<0.05),不同PDW组间MACCE比较,差异有统计学意义(P<0.05)。校正混杂因素后Cox回归分析显示,术前PDW与PCI术后发生缺血性卒中、不稳定性心绞痛、急性ST段抬高性心肌梗死、急性非ST段抬高性心肌梗死及随访死亡均呈正相关,是患者预后的危险因素(HR均>1,P均<0.05)。结论:术前PDW是PCI患者术后独立的危险因素,可以作为未来预测PCI患者预后的指标。展开更多
The relief degree of land surface （RDLS） is an important factor for describing the landform at macro-scales. This study defines a concept for RDLS and applies the concept for population distribution study of the ent...The relief degree of land surface （RDLS） is an important factor for describing the landform at macro-scales. This study defines a concept for RDLS and applies the concept for population distribution study of the entire country. Based on the concept and macro-scale digital elevation model datum and ARC/INFO software, the RDLS at a 10 km×10 km grid size of China is extracted. This paper depicts systemically the spatial distributions of RDLS through analyzing the ratio structure and altitudinal characters of RDLS in China. The conclusions are drawn as follows： the RDLS in more than 63% of the area is less than one （1） （relative altitude is less than 500 m）, reflecting the fact that most of RDLS in China is low. In general, the RDLS in the west is larger than that in the east and so is the south than that of the north in China. The RDLS decreases with the increase of longitude and latitude and the change of RDLS at the latitudes of 28°N, 35°N, 42°N, as well as at the longitudes of 85°E, 102°E, 115°E could reflect the three major ladders of China. In the vertical direction, the RDLS increases with the increase of altitude. Analysis of the correlation between RDLS and population distribution in China and its regional difference shows that the R2 value between RDLS and population density is 0.91 and RDLS is an important factor influencing the spatial distribution of population. More than 85% of the people in China live in areas where the RDLS is less than one （1）, while the population in areas with RDLS greater than 3 accounts only for 0.57% of the total. The regional difference of correlation between RDLS and population within China is significant and such correlation is significant in Central China and South China and weak in Inner Mongolia and Tibet.展开更多
Climate is one important environmental variable that affects human life.As the regions along the Belt and Road(B&R)encompass vast territories and large populations,it is significant to assess climate suitability f...Climate is one important environmental variable that affects human life.As the regions along the Belt and Road(B&R)encompass vast territories and large populations,it is significant to assess climate suitability for human settlements,which will influence the migration of various surrounding countries.We selected seven regions including 65 countries along the B&R for the research area and adopted the temperature-humidity index(THI),to assess the climate suitability.We analyzed the spatial characteristics of THI and the correlation between population distribution and THI,the results of which enabled us to adjust the THI classification criteria.We finally assessed the climate suitability of each region.The results reveal that outside the Qinghai-Tibet Plateau,the THI values generally tend to decrease from west to east as longitude increases and downward with increasing latitude.The population distribution is significantly correlated with the THI.Regions with relative suitable climate,including high suitability areas(HASs),moderately suitable areas(MSAs)and low suitability areas(LSAs),account for 50.62%of the total area and encompass in excess of 90%of total population.These areas are widely distributed in the southern regions of 45°N latitude,again with the exception of the Qinghai-Tibet Plateau.Critical suitable area includes 19.48%of the entire area and 8.98%of total population.The non-suitable area accounts for less than 30%of total area,concentrated in the cold high-latitude and high-altitude areas.展开更多
Autumn Arctic sea ice has been declining since the beginning of the era of satellite sea ice observations.In this study,we examined the factors contributing to the decline of autumn sea ice concentration.From the Beau...Autumn Arctic sea ice has been declining since the beginning of the era of satellite sea ice observations.In this study,we examined the factors contributing to the decline of autumn sea ice concentration.From the Beaufort Sea to the Barents Sea,autumn sea ice concentration has decreased considerably between 1982 and 2020,and the rates of decline were the highest around the Beaufort Sea.We calculated the correlation coefficients between sea ice extent(SIE)anomalies and anomalies of sea surface temperature(SST),surface air temperature(SAT)and specific humidity(SH).Among these coefficients,the largest absolute value was found in the coefficient between SIE and SAT anomalies for August to October,which has a value of−0.9446.The second largest absolute value was found in the coefficient between SIE and SH anomalies for September to November,which has a value of−0.9436.Among the correlation coefficients between SIE and SST anomalies,the largest absolute value was found in the coefficient for August to October,which has a value of−0.9410.We conducted empirical orthogonal function(EOF)analyses of sea ice,SST,SAT,SH,sea level pressure(SLP)and the wind field for the months where the absolute values of the correlation coefficient were the largest.The first EOFs of SST,SAT and SH account for 39.07%,63.54%and 47.60%of the total variances,respectively,and are mainly concentrated in the area between the Beaufort Sea and the East Siberian Sea.The corresponding principal component time series also indicate positive trends.The first EOF of SLP explains 41.57%of the total variance.It is mostly negative in the central Arctic.Over the Beaufort,Chukchi and East Siberian seas,the zonal wind weakened while the meridional wind strengthened.Results from the correlation and EOF analyses further verified the effects of the ice-temperature,ice-SH and ice-SLP feedback mechanisms in the Arctic.These mechanisms accelerate melting and decrease the rate of formation of sea ice.In addition,stronger meridional winds favor the flow of warm air from lower latitudes towards the polar region,further promoting Arctic sea ice decline.展开更多
文摘目的:探讨冠心病患者介入术前血小板体积分布宽度(platelet distribution width,PDW)与预后的相关性。方法:采用回顾性研究的方法,收集2014年10月至2020年10月期间在首都医科大学附属北京安贞医院住院治疗的PCI患者13090例,所有患者均于我院术前完善静脉血常规检测,该项检测中包括PDW。将上述所有PCI患者基于PDW数值四等分分组,第一组(PDW≤11.6%)3286例,第二组(11.6%<PDW≤13.3%)3281例,第三组(13.3%<PDW≤17.4%)3280例,第四组(PDW>17.4%)3243例。收集患者资料并进行随访,记录主要的心脑血管不良事件(major adverse cardiovascular and cerebrovascular events,MACCE)及死亡。采用多因素矫正混杂因素的Cox回归分析,研究术前PDW对PCI患者预后的影响。结果:不同PDW组间年龄、陈旧性心肌梗死、心房颤动等,差异均有统计学意义(P<0.05),不同PDW组间MACCE比较,差异有统计学意义(P<0.05)。校正混杂因素后Cox回归分析显示,术前PDW与PCI术后发生缺血性卒中、不稳定性心绞痛、急性ST段抬高性心肌梗死、急性非ST段抬高性心肌梗死及随访死亡均呈正相关,是患者预后的危险因素(HR均>1,P均<0.05)。结论:术前PDW是PCI患者术后独立的危险因素,可以作为未来预测PCI患者预后的指标。
基金Knowledge Innovation Project of the CAS,No.KZCX2-YW-323
文摘The relief degree of land surface （RDLS） is an important factor for describing the landform at macro-scales. This study defines a concept for RDLS and applies the concept for population distribution study of the entire country. Based on the concept and macro-scale digital elevation model datum and ARC/INFO software, the RDLS at a 10 km×10 km grid size of China is extracted. This paper depicts systemically the spatial distributions of RDLS through analyzing the ratio structure and altitudinal characters of RDLS in China. The conclusions are drawn as follows： the RDLS in more than 63% of the area is less than one （1） （relative altitude is less than 500 m）, reflecting the fact that most of RDLS in China is low. In general, the RDLS in the west is larger than that in the east and so is the south than that of the north in China. The RDLS decreases with the increase of longitude and latitude and the change of RDLS at the latitudes of 28°N, 35°N, 42°N, as well as at the longitudes of 85°E, 102°E, 115°E could reflect the three major ladders of China. In the vertical direction, the RDLS increases with the increase of altitude. Analysis of the correlation between RDLS and population distribution in China and its regional difference shows that the R2 value between RDLS and population density is 0.91 and RDLS is an important factor influencing the spatial distribution of population. More than 85% of the people in China live in areas where the RDLS is less than one （1）, while the population in areas with RDLS greater than 3 accounts only for 0.57% of the total. The regional difference of correlation between RDLS and population within China is significant and such correlation is significant in Central China and South China and weak in Inner Mongolia and Tibet.
基金Under the auspices of the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA20010203,XDA20010201)the Second Tibetan Plateau Scientific Expedition and Research Program(No.2019QZKK1006)+1 种基金Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.CAS2020055)National Natural Science Foundation of China(No.41901086)。
文摘Climate is one important environmental variable that affects human life.As the regions along the Belt and Road(B&R)encompass vast territories and large populations,it is significant to assess climate suitability for human settlements,which will influence the migration of various surrounding countries.We selected seven regions including 65 countries along the B&R for the research area and adopted the temperature-humidity index(THI),to assess the climate suitability.We analyzed the spatial characteristics of THI and the correlation between population distribution and THI,the results of which enabled us to adjust the THI classification criteria.We finally assessed the climate suitability of each region.The results reveal that outside the Qinghai-Tibet Plateau,the THI values generally tend to decrease from west to east as longitude increases and downward with increasing latitude.The population distribution is significantly correlated with the THI.Regions with relative suitable climate,including high suitability areas(HASs),moderately suitable areas(MSAs)and low suitability areas(LSAs),account for 50.62%of the total area and encompass in excess of 90%of total population.These areas are widely distributed in the southern regions of 45°N latitude,again with the exception of the Qinghai-Tibet Plateau.Critical suitable area includes 19.48%of the entire area and 8.98%of total population.The non-suitable area accounts for less than 30%of total area,concentrated in the cold high-latitude and high-altitude areas.
基金the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)(Grant no.2018SDKJ0106-1)Open Fund of the Key Laboratory of Ocean Circulation and Waves,Chinese Academy of Sciences(Grant no.KLOCW2003)the Project of Doctoral Found of Qingdao University of Science and Technology(Grant no.210010022746)。
文摘Autumn Arctic sea ice has been declining since the beginning of the era of satellite sea ice observations.In this study,we examined the factors contributing to the decline of autumn sea ice concentration.From the Beaufort Sea to the Barents Sea,autumn sea ice concentration has decreased considerably between 1982 and 2020,and the rates of decline were the highest around the Beaufort Sea.We calculated the correlation coefficients between sea ice extent(SIE)anomalies and anomalies of sea surface temperature(SST),surface air temperature(SAT)and specific humidity(SH).Among these coefficients,the largest absolute value was found in the coefficient between SIE and SAT anomalies for August to October,which has a value of−0.9446.The second largest absolute value was found in the coefficient between SIE and SH anomalies for September to November,which has a value of−0.9436.Among the correlation coefficients between SIE and SST anomalies,the largest absolute value was found in the coefficient for August to October,which has a value of−0.9410.We conducted empirical orthogonal function(EOF)analyses of sea ice,SST,SAT,SH,sea level pressure(SLP)and the wind field for the months where the absolute values of the correlation coefficient were the largest.The first EOFs of SST,SAT and SH account for 39.07%,63.54%and 47.60%of the total variances,respectively,and are mainly concentrated in the area between the Beaufort Sea and the East Siberian Sea.The corresponding principal component time series also indicate positive trends.The first EOF of SLP explains 41.57%of the total variance.It is mostly negative in the central Arctic.Over the Beaufort,Chukchi and East Siberian seas,the zonal wind weakened while the meridional wind strengthened.Results from the correlation and EOF analyses further verified the effects of the ice-temperature,ice-SH and ice-SLP feedback mechanisms in the Arctic.These mechanisms accelerate melting and decrease the rate of formation of sea ice.In addition,stronger meridional winds favor the flow of warm air from lower latitudes towards the polar region,further promoting Arctic sea ice decline.
