Land use reflects human activities on land.Urban land use is the highest level human alteration on Earth,and it is rapidly changing due to population increase and urbanization.Urban areas have widespread effects on lo...Land use reflects human activities on land.Urban land use is the highest level human alteration on Earth,and it is rapidly changing due to population increase and urbanization.Urban areas have widespread effects on local hydrology,climate,biodiversity,and food production[1,2].However,maps,that contain knowledge on the distribution,pattern and composition of various land use types in urban areas,are limited to city level.The mapping standard on data sources,methods,land use classification schemes varies from city to city,due to differences in financial input and skills of mapping personnel.To address various national and global environmental challenges caused by urbanization,it is important to have urban land uses at the national and global scales that are derived from the same or consistent data sources with the same or compatible classification systems and mapping methods.This is because,only with urban land use maps produced with similar criteria,consistent environmental policies can be made,and action efforts can be compared and assessed for large scale environmental administration.However,despite of the fact that a number of urban-extent maps exist at global scales[3,4],more detailed urban land use maps do not exist at the same scale.Even at big country or regional levels such as for the United States,China and European Union,consistent land use mapping efforts are rare[5,6](e.g.,https://sdi4apps.eu/open_land_use/).展开更多
Starting from December 2019,Wuhan,China,encountered the first outbreak of coronavirus disease 2019(COVID-19)(1-2).The epidemic was successfully suppressed by strict containment so that the number of infected people wa...Starting from December 2019,Wuhan,China,encountered the first outbreak of coronavirus disease 2019(COVID-19)(1-2).The epidemic was successfully suppressed by strict containment so that the number of infected people was reduced to 0 on April 8,2020(3–4).After that,China experienced roughly 3 dozen outbreaks with local transmission caused by imported severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).展开更多
目的:探讨急性A型主动脉夹层(acute type A aortic dissection,ATAAD)患者围手术期血浆P-选择素水平与急性肺损伤(acute lung injury,ALI)的关系。方法:ATAAD患者46例,根据围手术期ALI诊断标准分为两组:术前ALI组(A组,24例)和术前非ALI...目的:探讨急性A型主动脉夹层(acute type A aortic dissection,ATAAD)患者围手术期血浆P-选择素水平与急性肺损伤(acute lung injury,ALI)的关系。方法:ATAAD患者46例,根据围手术期ALI诊断标准分为两组:术前ALI组(A组,24例)和术前非ALI组(NA组,22例)。所有患者均在全身麻醉和深低温停循环(deep hypothermic circulatory arrest,DHCA)下行孙氏手术(主动脉弓人工血管替换和象鼻支架植入术)。分别于麻醉诱导前(T0)、手术结束时(T1)和术后12 h(T2)抽取动脉血行血气分析,计算氧合指数(oxygenation index,OI),并同时抽取静脉血检测血浆P-选择素水平、血小板计数(platelet count,PC)、平均血小板体积(mean platelet volume,MPV)、血小板分布宽度(platelet distribution width,PDW)。结果:A组患者各时点OI低于NA组(P<0.05);与T0比较,A组患者T1时OI降低、T2时增高,NA组患者T1、T2时OI均降低(P<0.05)。A组患者各时点血浆P-选择素水平高于NA组(P<0.05),T0时PC低于NA组(P<0.05)。与T0比较,两组患者T1时血浆P-选择素水平、PDW增高,PC、MPV降低(P<0.05);T2时血浆P-选择素水平增高,PC降低(P<0.05)。血浆P-选择素水平与OI呈负相关(r=-0.793,P<0.05)。结论:ATAAD患者围手术期多种因素导致血小板活化、血浆P-选择素水平增高,是围手术期发生ALI的重要因素。围手术期采取措施减少血小板活化、降低血浆P-选择素水平可能有助于ALI的防治。展开更多
基金partially supported by the National Key Research and Development Program of China(2016YFA0600104)supported by donations made by Delos Living LLC,and the Cyrus Tang Foundation+2 种基金supported by the National Natural Science Foundation of China(41471419)Beijing Institute of Urban Planningsupported by the Fundamental Research Funds for the Central Universities(CCNU19TD002).
文摘Land use reflects human activities on land.Urban land use is the highest level human alteration on Earth,and it is rapidly changing due to population increase and urbanization.Urban areas have widespread effects on local hydrology,climate,biodiversity,and food production[1,2].However,maps,that contain knowledge on the distribution,pattern and composition of various land use types in urban areas,are limited to city level.The mapping standard on data sources,methods,land use classification schemes varies from city to city,due to differences in financial input and skills of mapping personnel.To address various national and global environmental challenges caused by urbanization,it is important to have urban land uses at the national and global scales that are derived from the same or consistent data sources with the same or compatible classification systems and mapping methods.This is because,only with urban land use maps produced with similar criteria,consistent environmental policies can be made,and action efforts can be compared and assessed for large scale environmental administration.However,despite of the fact that a number of urban-extent maps exist at global scales[3,4],more detailed urban land use maps do not exist at the same scale.Even at big country or regional levels such as for the United States,China and European Union,consistent land use mapping efforts are rare[5,6](e.g.,https://sdi4apps.eu/open_land_use/).
基金Supported by the National Natural Science Foundation(grant number 71934002)of the People’s Republic of China.
文摘Starting from December 2019,Wuhan,China,encountered the first outbreak of coronavirus disease 2019(COVID-19)(1-2).The epidemic was successfully suppressed by strict containment so that the number of infected people was reduced to 0 on April 8,2020(3–4).After that,China experienced roughly 3 dozen outbreaks with local transmission caused by imported severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).
