目的探讨3.0 T MRI联合小剂量高浓度对比剂(钆布醇)行对比增强磁共振血管成像(CE-MRA)及动态磁敏感对比增强灌注加权成像(DSC-PWI)对于急性缺血性脑卒中(AIS)患者的应用价值。方法前瞻性纳入临床怀疑AIS且需行CE-MRA及DSC-PWI的患者50例...目的探讨3.0 T MRI联合小剂量高浓度对比剂(钆布醇)行对比增强磁共振血管成像(CE-MRA)及动态磁敏感对比增强灌注加权成像(DSC-PWI)对于急性缺血性脑卒中(AIS)患者的应用价值。方法前瞻性纳入临床怀疑AIS且需行CE-MRA及DSC-PWI的患者50例,随机分为常规浓度组(25例,钆喷酸葡胺0.2 mL/kg)和高浓度组(25例,钆布醇0.06 mL/kg)。比较两组患者的图像质量评分、信号差异、血管狭窄情况及缺血半暗带情况。结果高浓度组与常规浓度组间图像质量评分的差异无统计学意义(3.54±0.32比3.44±0.58;t=0.752,P=0.457)。高浓度组颈总动脉分叉处信号强度(SI)(448.57±180.93)、信噪比(SNR)(196.05±70.86)、对比噪声比(CNR)(183.32±68.08)稍高于常规浓度组(426.99±147.88、189.39±55.89、178.34±53.68),差异无统计学意义(均P>0.05)。高浓度组大脑中动脉起始处SI(393.67±133.02)、SNR(254.61±81.03)、CNR(235.46±77.72)均高于常规浓度组(353.67±139.78、197.78±58.62、183.44±56.52),两组间SI差异无统计学意义(P>0.05),而两组间SNR、CNR的差异均有统计学意义(均P<0.05)。两组CE-MRA诊断动脉狭窄观察者之间一致性均较强(κ=0.763、0.819)。两组DSC-PWI诊断缺血半暗带观察者之间一致性均较强(κ=0.84、0.883)。结论使用小剂量高浓度对比剂行3.0 T MRI是一种可行的急性缺血性脑卒中MRI扫描方案。展开更多
The distinctive estuary hydrodynamics and nutrient input make the estuary ecosystem play a key role in lake ecosystems.The Nanfei River and Zhaohe River are two main inlets of Chaohu Lake,Anhui,East China.We selected ...The distinctive estuary hydrodynamics and nutrient input make the estuary ecosystem play a key role in lake ecosystems.The Nanfei River and Zhaohe River are two main inlets of Chaohu Lake,Anhui,East China.We selected estuaries of the two rivers as representative areas to study temporal and spatial changes of bacterial communities.In August(summer)and November(autumn)2016 and February(winter)and May(spring)2017,16 water and sediment samples were collected from the estuaries.Physicochemical characteristics indicate significant differences in the nutritional status and eutrophication index of the estuaries due mainly to organic input.Examination of the number of operational taxonomic units,the diversity index,the community composition,and redundancy analysis revealed the following.First,the existence of varying degrees of seasonal differences in the distribution of almost all bacteria.In addition,the species diversity in the sediment samples was higher than that in the water samples,and the dominant species differed also among these samples.Second,a large number of unknown genera were detected,especially in the sediment samples,such as unclassified Xanthomonadales incertae sedis,unclassified Anaerolineaceae,and unclassified Alcaligenaceae.Last,TP,TN,and TOC were the main influential factors that affected the bacterial community structure.展开更多
Based on 11004 satellite images from CBERS CCD and Landsat TM/ETM,changes in the spatial characteristics of all lakes in China were determined following pre-established interpretation rules.This dataset was supported ...Based on 11004 satellite images from CBERS CCD and Landsat TM/ETM,changes in the spatial characteristics of all lakes in China were determined following pre-established interpretation rules.This dataset was supported by 6843 digital raster images(1:100000 and 1:50000),a countrywide digital vector dataset(1:250000),and historical literature.Comparative data were corrected for seasonal variations using precipitation data.There are presently 2693 natural lakes in China with an area greater than 1.0 km2,excluding reservoirs.These lakes are distributed in 28 provinces,autonomous regions and municipalities and have a total area of 81414.6 km2,accounting for-0.9% of China's total land area.In the past 30 years,the number of newly formed and newly discovered lakes with an area greater than 1.0 km2 is 60 and 131,respectively.Conversely,243 lakes have disappeared in this time period.展开更多
文摘目的探讨3.0 T MRI联合小剂量高浓度对比剂(钆布醇)行对比增强磁共振血管成像(CE-MRA)及动态磁敏感对比增强灌注加权成像(DSC-PWI)对于急性缺血性脑卒中(AIS)患者的应用价值。方法前瞻性纳入临床怀疑AIS且需行CE-MRA及DSC-PWI的患者50例,随机分为常规浓度组(25例,钆喷酸葡胺0.2 mL/kg)和高浓度组(25例,钆布醇0.06 mL/kg)。比较两组患者的图像质量评分、信号差异、血管狭窄情况及缺血半暗带情况。结果高浓度组与常规浓度组间图像质量评分的差异无统计学意义(3.54±0.32比3.44±0.58;t=0.752,P=0.457)。高浓度组颈总动脉分叉处信号强度(SI)(448.57±180.93)、信噪比(SNR)(196.05±70.86)、对比噪声比(CNR)(183.32±68.08)稍高于常规浓度组(426.99±147.88、189.39±55.89、178.34±53.68),差异无统计学意义(均P>0.05)。高浓度组大脑中动脉起始处SI(393.67±133.02)、SNR(254.61±81.03)、CNR(235.46±77.72)均高于常规浓度组(353.67±139.78、197.78±58.62、183.44±56.52),两组间SI差异无统计学意义(P>0.05),而两组间SNR、CNR的差异均有统计学意义(均P<0.05)。两组CE-MRA诊断动脉狭窄观察者之间一致性均较强(κ=0.763、0.819)。两组DSC-PWI诊断缺血半暗带观察者之间一致性均较强(κ=0.84、0.883)。结论使用小剂量高浓度对比剂行3.0 T MRI是一种可行的急性缺血性脑卒中MRI扫描方案。
基金Supported by the National Natural Science Foundation of China(Nos.41601573,41771235)the Key University Science Research Project of Anhui Province(No.KJ2019A0641)+1 种基金the Linkage Project of Anhui Public Welfare Technology Application Research(No.1704f0804053)the Science and the Technology Innovation Strategy and Soft Science Research Special Project of Anhui Province(No.1706a02020048)。
文摘The distinctive estuary hydrodynamics and nutrient input make the estuary ecosystem play a key role in lake ecosystems.The Nanfei River and Zhaohe River are two main inlets of Chaohu Lake,Anhui,East China.We selected estuaries of the two rivers as representative areas to study temporal and spatial changes of bacterial communities.In August(summer)and November(autumn)2016 and February(winter)and May(spring)2017,16 water and sediment samples were collected from the estuaries.Physicochemical characteristics indicate significant differences in the nutritional status and eutrophication index of the estuaries due mainly to organic input.Examination of the number of operational taxonomic units,the diversity index,the community composition,and redundancy analysis revealed the following.First,the existence of varying degrees of seasonal differences in the distribution of almost all bacteria.In addition,the species diversity in the sediment samples was higher than that in the water samples,and the dominant species differed also among these samples.Second,a large number of unknown genera were detected,especially in the sediment samples,such as unclassified Xanthomonadales incertae sedis,unclassified Anaerolineaceae,and unclassified Alcaligenaceae.Last,TP,TN,and TOC were the main influential factors that affected the bacterial community structure.
基金supported by the National Special Basic Research Project (Gran No. 2006FY110600)
文摘Based on 11004 satellite images from CBERS CCD and Landsat TM/ETM,changes in the spatial characteristics of all lakes in China were determined following pre-established interpretation rules.This dataset was supported by 6843 digital raster images(1:100000 and 1:50000),a countrywide digital vector dataset(1:250000),and historical literature.Comparative data were corrected for seasonal variations using precipitation data.There are presently 2693 natural lakes in China with an area greater than 1.0 km2,excluding reservoirs.These lakes are distributed in 28 provinces,autonomous regions and municipalities and have a total area of 81414.6 km2,accounting for-0.9% of China's total land area.In the past 30 years,the number of newly formed and newly discovered lakes with an area greater than 1.0 km2 is 60 and 131,respectively.Conversely,243 lakes have disappeared in this time period.
