目的提高对肺毛霉菌病临床特征的认识,进一步分析肺毛霉菌病患者死亡的危险因素。方法回顾性收集2017年1月至2023年6月于首都医科大学附属北京朝阳医院住院的25例肺毛霉菌病病例的易患因素、临床表现、实验室检查、影像学特征、治疗预...目的提高对肺毛霉菌病临床特征的认识,进一步分析肺毛霉菌病患者死亡的危险因素。方法回顾性收集2017年1月至2023年6月于首都医科大学附属北京朝阳医院住院的25例肺毛霉菌病病例的易患因素、临床表现、实验室检查、影像学特征、治疗预后等资料,其中易患因素、临床表现、影像学特征及预后资料分析应用Fisher精确检验,实验室检查数据应用独立样本t检验或Mann-Whitney U检验进行分析,对差异有统计学意义的参数进行单因素回归分析,以寻找肺毛霉菌病死亡的危险因素。结果25例患者中男性15例,平均年龄(52.64±13.74)(32~76)岁,住院时间15(10.5,21.5)d,最常见的肺毛霉菌病易患因素有糖尿病(20/25)、糖皮质激素暴露(13/25)、毛霉不敏感抗真菌药物应用(10/25)和实体器官移植(5/25)。最常见的临床症状为发热(21/25)和咳嗽(21/25),其次为呼吸困难(10/25)、咯血或痰中带血(9/25)。其中死亡患者8例,与存活患者相比,死亡组患者住院时间较短(P=0.003),有实体器官移植史占比更高(P=0.023),余一般情况及易患因素在两组间差异无统计学意义。死亡组患者血小板水平低于存活组患者[174(78,227)×10^(9)/L vs 310(229,347)×10^(9)/L],两组间差异有统计学意义(P=0.030)。25例患者中最常见的毛霉目真菌为根霉属(包括少根根霉、小孢根霉等)和根毛霉属(主要为微小根毛霉)。肺内多发结节影是存活组患者更为多见的影像学改变,两组间差异有统计学意义(P=0.042)。肺毛霉菌治疗包括敏感的抗真菌药物和手术或介入治疗,存活组和死亡组患者治疗方案无明显差异。实体器官移植增加了肺毛霉菌病患者的死亡风险(OR=16.000,95%CI:1.381~185.405,P=0.027)。结论肺毛霉菌病病死率高,存在糖尿病以及糖皮质激素暴露、使用免疫抑制剂、实体器官移植等是目前较常见的易患因素,其临床表现和实验室检查大多无特异性,多叶病变、胸腔积液、气管狭窄或闭塞、楔形实变、肺内多发结节等是常见的影像学特征。在上述临床特征中,实体器官移植受者、血小板水平偏低的患者病死率更高,其中实体器官移植增加了肺毛霉菌病患者死亡的风险。展开更多
通常采用大量掺加辅助性胶凝材料的方式提高胶凝材料的抗Cl^(–)渗透性能,进而提升混凝土结构的耐久性和服役寿命,但会显著降低早期力学性能.为提高早期强度和抗Cl^(–)渗透性能,基于初始浆体密堆积与水化过程孔隙有效填充,设计细、中...通常采用大量掺加辅助性胶凝材料的方式提高胶凝材料的抗Cl^(–)渗透性能,进而提升混凝土结构的耐久性和服役寿命,但会显著降低早期力学性能.为提高早期强度和抗Cl^(–)渗透性能,基于初始浆体密堆积与水化过程孔隙有效填充,设计细、中、粗粒度区间胶凝材料的种类和掺量,提高浆体的初始堆积密度和水化产物固氯能力,从而细化孔径并增大孔隙曲折度,采用59%的水泥熟料(粒径范围4~55μm),成功制备了3 d抗压强度27.3 MPa、28 d Cl^(–)扩散系数低至0.36×10^(–12)m^(2)/s的高抗渗透复合胶凝材料,为水泥基材料微结构调控和抗渗性能提升奠定基础.展开更多
拖延是指个体明知有害却仍自愿推迟执行任务的一种不理智行为.拖延不仅会对人们的情绪、学业表现以及社会成就等产生不利的影响,而且会降低人们的主观幸福感,更有甚者会损害人们的身心健康.关于拖延的神经基础,目前研究只探索了拖延和...拖延是指个体明知有害却仍自愿推迟执行任务的一种不理智行为.拖延不仅会对人们的情绪、学业表现以及社会成就等产生不利的影响,而且会降低人们的主观幸福感,更有甚者会损害人们的身心健康.关于拖延的神经基础,目前研究只探索了拖延和脑区局部活动及简单的功能连接的关系.然而,拖延行为涉及任务价值表征、认知控制、趋近与回避动机等复杂的心理过程,以单变量和局部的脑活动来对拖延的神经基础进行描述会存在可见的局限.因此本研究采用图论拓扑分析的方法从大尺度脑网络连接角度考察拖延的神经基础.首先,定义Power等人的全脑264个感兴趣区(regions of interest, ROIs)为网络的节点,进一步采用图论分析的方法重构了全脑10个固有大尺度脑网络,结果发现构建的脑网络具有较好的网络拓扑属性(如较高的局部效率和全局效率).其次,采用皮尔逊相关的方法计算了10个脑网络内以及网络间的功能连接的强度.最后,考察了脑网络连接的强度与拖延行为之间的关系.结果发现,拖延与扣带执行网络的内部连接存在显著的负相关,而与皮层下网络的内部连接存在显著的正相关;进一步的网络间的功能连接发现,突显网络与皮层下网络间的功能连接与拖延存在显著的正相关.这些结果表明,皮层下网络和扣带执行网络内的连接以及突显网络对皮层下网络的调节可能是特质性拖延的神经基础.本研究的结果证明了认知控制与冲动性价值表征等认知能力在拖延行为中的重要作用.展开更多
The Dongsha submarine canyon is a large canyon belonging to a group of canyons on the northeastern South China Sea margin Investigation of the Dongsha canyon is important for understanding the origin of this canyon gr...The Dongsha submarine canyon is a large canyon belonging to a group of canyons on the northeastern South China Sea margin Investigation of the Dongsha canyon is important for understanding the origin of this canyon group as well as the transport mechanism of sediments on the margin, and the evolution of the Taixinan foreland basin and the associated Taiwan orogenic belt. In this study, the morphology, sedimentary characteristics, and origin of the Dongsha canyon were investigated by inte- grating high-resolution multi-channel seismic reflection profiles and high-precision multibeam bathymetric data. This is a slope-confined canyon that originates in the upper slope east of the Dongsha Islands, extends downslope in the SEE direction, and finally merges with the South Taiwan Shoal canyon at a water depth of 3000 m. The total length and average width of the canyon are around 190 and 10 km, respectively. Eleven seismic sequence boundaries within the canyon fills were identified and interpreted as incision surfaces of the canyon. In the canyon fills, four types of seismic facies were defined： parallel onlap fill, chaotic fill, mounded divergent facies, and migrated wavy facies. The parallel onlap fill facies is interpreted as altemating coarser turbidites or other gravity-flow deposits and fine hemipelagic sediments filling the canyon valley. The chaotic fill faci- es is presumed to be debrites and/or basal lag deposits filling the thalwegs. The mounded divergent and migrated wavy seismic facies can be explained as canyon levees consisting mainly of overspilled fine turbidites and sediment waves on the levees or on the canyon-mouth submarine fans. Age correlation between the sequence boundaries and the ODP Site 1144 data suggests that the Dongsha canyon was initiated at approximately 0.9 Ma in the middle Pleistocene. Mapping of the canyon indicates that the canyon originated at the upstream portion of the middle reach of the modem canyon, and has been continuously expanding both upstream and downstream by retrogressive erosion, incision, and deposition of turbidity currents and other gravity transport processes. The ages of the sequence boundaries representing major canyon incision events are in good agreement with those of global sea-level lowstands, indicating that sea-level changes may have played an important role in the canyon＇s development. The Dongsha canyon developed in a region with an active tectonic background characterized by the Taiwan up- lifting and the development of the Taixinan foreland basin. However, no evidence suggests that the canyon formation is directly associated with local or regional faulting and magmatic activities. Turbidity currents and other gravity transport processes （includ- ing submarine slides and slumps） may have had an important influence on the formation and evolution of the canyon.展开更多
Modern atolls have been studied systematically and thoroughly in the South China Sea.However,the knowledge of a paleo-atoll and related sedimentary system is very limited.Here we used the newly acquired high resolutio...Modern atolls have been studied systematically and thoroughly in the South China Sea.However,the knowledge of a paleo-atoll and related sedimentary system is very limited.Here we used the newly acquired high resolution 2D seismic data,and discovered three late Miocene atoll systems in the offshore Xisha Islands for the first time.We named them atoll system A,B,C,respectively.These three atoll systems,all developed on the horsts dominated by normal fault,consist mainly of atoll reefs,patch reefs,fore-reef slope deposits,and lagoons.On the basis of the interpreted sequence stratigraphic framework and the identification of fore-reef slope deposits,we suggested only the atoll system A continued to grow until Quaternary,and both of atoll system B and C had been drowned in Pliocene.In late Miocene,the atoll systems in the study area were most developed,either in magnitude or in maturity,which indicated late Miocene was the most flourishing period of reef builders,and this was in accordance with the drilling result of ODP Leg 184 in the South China Sea.Pliocene was an important reef drowning period in the study area,and both atoll systems B and C were drowned and hemipelagic deposits prevailed gradually.Quaternary was another reef drowning period in the study area,two large atoll reefs grown on the atoll system A were finally drowned,and hemipelagic deposits begun to drape and fill the palaeo-atoll systems.The growth and drowning of atolls are controlled mainly by tectonic subsidence in long term,but global eustatic can impact it in short term also.展开更多
文摘目的提高对肺毛霉菌病临床特征的认识,进一步分析肺毛霉菌病患者死亡的危险因素。方法回顾性收集2017年1月至2023年6月于首都医科大学附属北京朝阳医院住院的25例肺毛霉菌病病例的易患因素、临床表现、实验室检查、影像学特征、治疗预后等资料,其中易患因素、临床表现、影像学特征及预后资料分析应用Fisher精确检验,实验室检查数据应用独立样本t检验或Mann-Whitney U检验进行分析,对差异有统计学意义的参数进行单因素回归分析,以寻找肺毛霉菌病死亡的危险因素。结果25例患者中男性15例,平均年龄(52.64±13.74)(32~76)岁,住院时间15(10.5,21.5)d,最常见的肺毛霉菌病易患因素有糖尿病(20/25)、糖皮质激素暴露(13/25)、毛霉不敏感抗真菌药物应用(10/25)和实体器官移植(5/25)。最常见的临床症状为发热(21/25)和咳嗽(21/25),其次为呼吸困难(10/25)、咯血或痰中带血(9/25)。其中死亡患者8例,与存活患者相比,死亡组患者住院时间较短(P=0.003),有实体器官移植史占比更高(P=0.023),余一般情况及易患因素在两组间差异无统计学意义。死亡组患者血小板水平低于存活组患者[174(78,227)×10^(9)/L vs 310(229,347)×10^(9)/L],两组间差异有统计学意义(P=0.030)。25例患者中最常见的毛霉目真菌为根霉属(包括少根根霉、小孢根霉等)和根毛霉属(主要为微小根毛霉)。肺内多发结节影是存活组患者更为多见的影像学改变,两组间差异有统计学意义(P=0.042)。肺毛霉菌治疗包括敏感的抗真菌药物和手术或介入治疗,存活组和死亡组患者治疗方案无明显差异。实体器官移植增加了肺毛霉菌病患者的死亡风险(OR=16.000,95%CI:1.381~185.405,P=0.027)。结论肺毛霉菌病病死率高,存在糖尿病以及糖皮质激素暴露、使用免疫抑制剂、实体器官移植等是目前较常见的易患因素,其临床表现和实验室检查大多无特异性,多叶病变、胸腔积液、气管狭窄或闭塞、楔形实变、肺内多发结节等是常见的影像学特征。在上述临床特征中,实体器官移植受者、血小板水平偏低的患者病死率更高,其中实体器官移植增加了肺毛霉菌病患者死亡的风险。
文摘通常采用大量掺加辅助性胶凝材料的方式提高胶凝材料的抗Cl^(–)渗透性能,进而提升混凝土结构的耐久性和服役寿命,但会显著降低早期力学性能.为提高早期强度和抗Cl^(–)渗透性能,基于初始浆体密堆积与水化过程孔隙有效填充,设计细、中、粗粒度区间胶凝材料的种类和掺量,提高浆体的初始堆积密度和水化产物固氯能力,从而细化孔径并增大孔隙曲折度,采用59%的水泥熟料(粒径范围4~55μm),成功制备了3 d抗压强度27.3 MPa、28 d Cl^(–)扩散系数低至0.36×10^(–12)m^(2)/s的高抗渗透复合胶凝材料,为水泥基材料微结构调控和抗渗性能提升奠定基础.
文摘拖延是指个体明知有害却仍自愿推迟执行任务的一种不理智行为.拖延不仅会对人们的情绪、学业表现以及社会成就等产生不利的影响,而且会降低人们的主观幸福感,更有甚者会损害人们的身心健康.关于拖延的神经基础,目前研究只探索了拖延和脑区局部活动及简单的功能连接的关系.然而,拖延行为涉及任务价值表征、认知控制、趋近与回避动机等复杂的心理过程,以单变量和局部的脑活动来对拖延的神经基础进行描述会存在可见的局限.因此本研究采用图论拓扑分析的方法从大尺度脑网络连接角度考察拖延的神经基础.首先,定义Power等人的全脑264个感兴趣区(regions of interest, ROIs)为网络的节点,进一步采用图论分析的方法重构了全脑10个固有大尺度脑网络,结果发现构建的脑网络具有较好的网络拓扑属性(如较高的局部效率和全局效率).其次,采用皮尔逊相关的方法计算了10个脑网络内以及网络间的功能连接的强度.最后,考察了脑网络连接的强度与拖延行为之间的关系.结果发现,拖延与扣带执行网络的内部连接存在显著的负相关,而与皮层下网络的内部连接存在显著的正相关;进一步的网络间的功能连接发现,突显网络与皮层下网络间的功能连接与拖延存在显著的正相关.这些结果表明,皮层下网络和扣带执行网络内的连接以及突显网络对皮层下网络的调节可能是特质性拖延的神经基础.本研究的结果证明了认知控制与冲动性价值表征等认知能力在拖延行为中的重要作用.
基金supported by the National Natural Science Foundation of China(Grant Nos.91028003,41076020)the Guangzhou Marine Geological Survey(GMGS)(Grant No.GZH2011003-05)
文摘The Dongsha submarine canyon is a large canyon belonging to a group of canyons on the northeastern South China Sea margin Investigation of the Dongsha canyon is important for understanding the origin of this canyon group as well as the transport mechanism of sediments on the margin, and the evolution of the Taixinan foreland basin and the associated Taiwan orogenic belt. In this study, the morphology, sedimentary characteristics, and origin of the Dongsha canyon were investigated by inte- grating high-resolution multi-channel seismic reflection profiles and high-precision multibeam bathymetric data. This is a slope-confined canyon that originates in the upper slope east of the Dongsha Islands, extends downslope in the SEE direction, and finally merges with the South Taiwan Shoal canyon at a water depth of 3000 m. The total length and average width of the canyon are around 190 and 10 km, respectively. Eleven seismic sequence boundaries within the canyon fills were identified and interpreted as incision surfaces of the canyon. In the canyon fills, four types of seismic facies were defined： parallel onlap fill, chaotic fill, mounded divergent facies, and migrated wavy facies. The parallel onlap fill facies is interpreted as altemating coarser turbidites or other gravity-flow deposits and fine hemipelagic sediments filling the canyon valley. The chaotic fill faci- es is presumed to be debrites and/or basal lag deposits filling the thalwegs. The mounded divergent and migrated wavy seismic facies can be explained as canyon levees consisting mainly of overspilled fine turbidites and sediment waves on the levees or on the canyon-mouth submarine fans. Age correlation between the sequence boundaries and the ODP Site 1144 data suggests that the Dongsha canyon was initiated at approximately 0.9 Ma in the middle Pleistocene. Mapping of the canyon indicates that the canyon originated at the upstream portion of the middle reach of the modem canyon, and has been continuously expanding both upstream and downstream by retrogressive erosion, incision, and deposition of turbidity currents and other gravity transport processes. The ages of the sequence boundaries representing major canyon incision events are in good agreement with those of global sea-level lowstands, indicating that sea-level changes may have played an important role in the canyon＇s development. The Dongsha canyon developed in a region with an active tectonic background characterized by the Taiwan up- lifting and the development of the Taixinan foreland basin. However, no evidence suggests that the canyon formation is directly associated with local or regional faulting and magmatic activities. Turbidity currents and other gravity transport processes （includ- ing submarine slides and slumps） may have had an important influence on the formation and evolution of the canyon.
基金supported by the National Natural Science Foundation of China(Grant Nos.91028003,41406068)Open Foundation of Key Laboratory of Marine Mineral Resources,Ministry of Land and Resources(Grant No.KLMMR-2013-A-22)
文摘Modern atolls have been studied systematically and thoroughly in the South China Sea.However,the knowledge of a paleo-atoll and related sedimentary system is very limited.Here we used the newly acquired high resolution 2D seismic data,and discovered three late Miocene atoll systems in the offshore Xisha Islands for the first time.We named them atoll system A,B,C,respectively.These three atoll systems,all developed on the horsts dominated by normal fault,consist mainly of atoll reefs,patch reefs,fore-reef slope deposits,and lagoons.On the basis of the interpreted sequence stratigraphic framework and the identification of fore-reef slope deposits,we suggested only the atoll system A continued to grow until Quaternary,and both of atoll system B and C had been drowned in Pliocene.In late Miocene,the atoll systems in the study area were most developed,either in magnitude or in maturity,which indicated late Miocene was the most flourishing period of reef builders,and this was in accordance with the drilling result of ODP Leg 184 in the South China Sea.Pliocene was an important reef drowning period in the study area,and both atoll systems B and C were drowned and hemipelagic deposits prevailed gradually.Quaternary was another reef drowning period in the study area,two large atoll reefs grown on the atoll system A were finally drowned,and hemipelagic deposits begun to drape and fill the palaeo-atoll systems.The growth and drowning of atolls are controlled mainly by tectonic subsidence in long term,but global eustatic can impact it in short term also.
