As the basic administrative unit of China,counties have grown rapidly in recent years in the context of rapid urbanization,especially for counties located in mountainous areas.The drastic changes in land in mountainou...As the basic administrative unit of China,counties have grown rapidly in recent years in the context of rapid urbanization,especially for counties located in mountainous areas.The drastic changes in land in mountainous areas can easily cause irreversible damage to the sensitive ecological environment.Through the dual-objective suitability zoning of ecological and construction balance,regional sustainable land use patterns can be realized.In this study,Hantai District in Southern Shaanxi province,China,was chosen as the research area aiming at creating a balance between ecological supply and the development of construction in spatial planning.A dual-objective process evaluation system for ecological protection and construction development was proposed with 15 resistance factors selected from three attributes:natural ecology,economic society,and policy.The minimum resistance surface discrimination methods for ecological land and construction development land were proposed based on vertical space superposition and horizontal minimum cumulative resistance models.Finally,the land in Hantai District was divided into four development grades from the optimal angle of dual goals,i.e.,the construction core zone being 134.56 km^(2),the suitable construction zone 115.77 km2,the ecological buffer zone 153.74 km^(2),and the ecological control zone 151.93 km^(2),using the method combining resistance difference and threshold division.In addition,the development direction of each town under jurisdiction was identified.This study compensates for the deficiency of traditional methods that evaluate land only from a single vertical or horizontal process.展开更多
目的探讨肿瘤患者经外周静脉置入中心静脉导管(peripherally inserted central catheters,PICC)置管后2周内导管相关性血栓(PICC-related thrombosis,PICCRT)形成情况及其对置管静脉血流状态的动态影响,为实施血栓防控措施提供依据。方...目的探讨肿瘤患者经外周静脉置入中心静脉导管(peripherally inserted central catheters,PICC)置管后2周内导管相关性血栓(PICC-related thrombosis,PICCRT)形成情况及其对置管静脉血流状态的动态影响,为实施血栓防控措施提供依据。方法2019年5月–2020年7月,前瞻性纳入四川大学华西医院PICC置管的实体肿瘤患者,用彩色多普勒超声仪检测患者置管后2周内PICCRT形成情况,根据是否发生PICCRT以及有无血栓相关症状和体征,分为无血栓组、非症状性血栓组和症状性血栓组。比较每个时点PICCRT患者检出情况,及其置管前1天和置管后2周内置管静脉的血管直径和血流速度。结果有173例患者完成试验,126例(72.8%)形成了PICCRT,且均发生在置管后1周内。其中非症状性血栓95例,症状性血栓31例。PICC置管前后,非症状性血栓组和症状性血栓组的血管直径均小于无血栓组,血流速度慢于无血栓组,且差异随着导管留置时间延长而持续增加,差异均有统计学意义。结论PICC置管时选择血管直径大、血流速度快的静脉穿刺置管,可能有助于降低PICCRT;置管后1周是预防PICCRT的重点干预时间。展开更多
基金the Natural Science Foundation of Shaanxi(2021SF-458)National Key R&D Program of China(2019YFD1100901)。
文摘As the basic administrative unit of China,counties have grown rapidly in recent years in the context of rapid urbanization,especially for counties located in mountainous areas.The drastic changes in land in mountainous areas can easily cause irreversible damage to the sensitive ecological environment.Through the dual-objective suitability zoning of ecological and construction balance,regional sustainable land use patterns can be realized.In this study,Hantai District in Southern Shaanxi province,China,was chosen as the research area aiming at creating a balance between ecological supply and the development of construction in spatial planning.A dual-objective process evaluation system for ecological protection and construction development was proposed with 15 resistance factors selected from three attributes:natural ecology,economic society,and policy.The minimum resistance surface discrimination methods for ecological land and construction development land were proposed based on vertical space superposition and horizontal minimum cumulative resistance models.Finally,the land in Hantai District was divided into four development grades from the optimal angle of dual goals,i.e.,the construction core zone being 134.56 km^(2),the suitable construction zone 115.77 km2,the ecological buffer zone 153.74 km^(2),and the ecological control zone 151.93 km^(2),using the method combining resistance difference and threshold division.In addition,the development direction of each town under jurisdiction was identified.This study compensates for the deficiency of traditional methods that evaluate land only from a single vertical or horizontal process.
文摘目的探讨肿瘤患者经外周静脉置入中心静脉导管(peripherally inserted central catheters,PICC)置管后2周内导管相关性血栓(PICC-related thrombosis,PICCRT)形成情况及其对置管静脉血流状态的动态影响,为实施血栓防控措施提供依据。方法2019年5月–2020年7月,前瞻性纳入四川大学华西医院PICC置管的实体肿瘤患者,用彩色多普勒超声仪检测患者置管后2周内PICCRT形成情况,根据是否发生PICCRT以及有无血栓相关症状和体征,分为无血栓组、非症状性血栓组和症状性血栓组。比较每个时点PICCRT患者检出情况,及其置管前1天和置管后2周内置管静脉的血管直径和血流速度。结果有173例患者完成试验,126例(72.8%)形成了PICCRT,且均发生在置管后1周内。其中非症状性血栓95例,症状性血栓31例。PICC置管前后,非症状性血栓组和症状性血栓组的血管直径均小于无血栓组,血流速度慢于无血栓组,且差异随着导管留置时间延长而持续增加,差异均有统计学意义。结论PICC置管时选择血管直径大、血流速度快的静脉穿刺置管,可能有助于降低PICCRT;置管后1周是预防PICCRT的重点干预时间。
