目的探讨急性缺血性脑卒中(AIS)患者血栓四项、凝血指标与患者神经功能损伤严重程度及短期预后的相关性。方法将2022年6月至2024年6月溧阳市人民医院收治的100例AIS患者纳入本次回顾性研究,依据入院时美国国立卫生研究院卒中量表(NIHSS...目的探讨急性缺血性脑卒中(AIS)患者血栓四项、凝血指标与患者神经功能损伤严重程度及短期预后的相关性。方法将2022年6月至2024年6月溧阳市人民医院收治的100例AIS患者纳入本次回顾性研究,依据入院时美国国立卫生研究院卒中量表(NIHSS)评分分成轻度组(n=28)、中度组(n=50)和重度组(n=22);根据出院后90 d mRS评分将患者分为预后良好组(n=72)和预后不良组(n=28)。比较不同神经功能损伤程度患者、不同预后患者的血栓四项[凝血酶-抗凝血酶复合物(TAT)、纤溶酶-α2纤溶酶抑制物复合物(PIC)、血栓调节蛋白(TM)、组织纤溶酶原激活物/纤溶酶原激活物抑制剂-1复合物(tPAI-C)]和凝血指标[活化部分凝血酶原时间(APTT)、凝血酶原时间(PT)、D-二聚体、纤维蛋白原(FIB)];用Spearman相关性分析血栓四项、凝血指标与NIHSS评分的相关性;并采用多因素Logistic回归分析法分析影响AIS患者的短期预后的因素。结果3组的APTT、PT比较,差异均无统计学意义(P>0.05);3组的D-二聚体和FIB比较,差异均有统计学意义(P<0.05),重度组的D-二聚体、FIB分别为(1.50±0.17)mg/L、(3.57±0.61)g/L,均显著高于中度组[(1.17±0.25)mg/L、(3.10±0.72)g/L]、轻度组[(0.69±0.12)mg/L、(2.75±0.56)g/L],中度组的D-二聚体、FIB均显著高于轻度组,差异均有统计学意义(P<0.05)。3组的TM、TAT、PIC和t-PAIC比较,差异均有统计学意义(P<0.05),重度组的TM、TAT、PIC和t-PAIC分别为(23.76±3.40)IU/mL、(42.80±4.33)ng/mL、(1.90±0.32)mg/L、(34.78±3.50)μg/L,均显著高于中度组[(17.50±3.27)IU/mL、(35.55±4.62)ng/mL、(1.58±0.24)mg/L、(25.51±4.12)μg/L]和轻度组[(12.61±2.34)IU/mL、(26.39±3.77)ng/mL、(1.15±0.13)mg/L、(18.44±3.13)μg/L],中度组的TM、TAT、PIC和t-PAIC均显著高于轻度组,差异均有统计学意义(P<0.05)。Spearman相关性分析显示,血浆D-二聚体、FIB、TM、TAT、PIC、t-PAIC与AIS患者的NIHSS评分均呈正相关(r=0.798、0.630、0.695、0.753、0.673、0.720,P<0.05)。相比于预后良好组,预后不良组的D-二聚体、FIB和血栓四项均显著升高,差异均有统计学意义(P<0.05)。Logistic回归分析显示,D-二聚体、FIB、血栓四项均为影响AIS短期预后的独立危险因素(P<0.05)。结论D-二聚体、FIB、血栓四项与AIS患者病情严重程度密切相关,也是AIS患者短期预后不良的危险因素。展开更多
The expanding of material library of laser powder bed fusion(L-PBF)is of great significance to the development of material science.In this study,the biomedical Ti-13Nb-13Zr powder was mixed with the tantalum particles...The expanding of material library of laser powder bed fusion(L-PBF)is of great significance to the development of material science.In this study,the biomedical Ti-13Nb-13Zr powder was mixed with the tantalum particles(2 wt%−8 wt%)and fabricated by L-PBF.The microstructure consists of aβmatrix with partially unmelted pure tantalum distributed along the boundaries of molten pool owing to the Marangoni convention.Because the melting process of Ta absorbs lots of energy,the size of molten pool becomes smaller with the increase of Ta content.The fine microstructure exists in the center of melt pool while coarse microstructure is on the boundaries of melt pool because of the existence of heat-affected zone.The columnar-to-equiaxed transitions(CETs)happen in the zones near the unmelted Ta,and the low lattice mismatch induced by solid Ta phase is responsible for this phenomenon.The recrystallization texture is strengthened while the fiber texture is weakened when the tantalum content is increased.Due to the formation of refined martensiteα′grains during L-PBF,the compressive strengths of L-PBF-processed samples are higher than those fabricated by traditional processing technologies.The present research will provide an important reference for biomedical alloy design via L-PBF process in the future.展开更多
Previous studies have shown that reanalysis products contain large uncertainties in the Tibetan Plateau(TP),and the biases are location dependent.Therefore,these products must be evaluated with in situ observations pr...Previous studies have shown that reanalysis products contain large uncertainties in the Tibetan Plateau(TP),and the biases are location dependent.Therefore,these products must be evaluated with in situ observations prior to their applications.In this study,the authors compare the results of several reanalysis projects with independent sounding observations recorded in the Yarlung Tsangpo River valley in the Eastern Himalayas in June 2010.These reanalysis projects include Climate Forecast System Reanalysis(CFSR),Interim European Centre for Medium Range Weather Forecasts Reanalysis(ERA- Interim),Japanese 25-year Reanalysis(JRA-25),Modern Era Retrospective Analysis for Research and Applications(MERRA),National Center for Environmental Prediction and the Department of Energy Reanalysis 2(NCEP-R2),and NCEP Final Analysis(FNL).Statistical quantities such as average,mean bias(MB),root-mean-square difference(RMSD),and correlation coefficient(R) of temperature,specific humidity,u-wind,and v-wind between 100 hPa and 650 hPa were calculated.The authors determined that the performance of each product differed with variables at different levels.The average profiles of the variables were captured by the reanalysis products,with large biases appearing at lower levels.ERA-Interim and NCEP-R2 showed the best and worst performances,respectively,for all variables.This study suggests that users should select appropriate reanalysis products according to their specific purposes for TP research.展开更多
To investigate the impacts of the quasi-biennial oscillation （QBO） on high-latitude circulation and the Arctic vortex, stratospheric zonal wind at 55-65°N is analyzed. The seasonal cycle, solar cycle, and linea...To investigate the impacts of the quasi-biennial oscillation （QBO） on high-latitude circulation and the Arctic vortex, stratospheric zonal wind at 55-65°N is analyzed. The seasonal cycle, solar cycle, and linear trend in the zonal wind at these latitudes are analyzed and removed, and the QBO signal is retrieved from the monthly zonal wind for the period 1979-2014. The zonal wind has a strong decreasing trend in winter, with a maximum decrease （less than -0.35 m s-1 yr-1） occurring within 70-100°E. The zonal wind has an in-phase response of 1.6 m s-1 to the solar cycle, with a maximum within 100-140°E. A clear QBO signal is detected in the zonal wind during the period 1979-2014, with an amplitude of 2.5 m s-1 and a period of 30 months. The latitudinal distribution of the QBO signal is inhomogeneous, with a maximum within 120-180°E and a minimum within 25-45°E.展开更多
Using observed wind and water vapor data from June 2006,water vapor exchange between the Rongbuk Valley and its above atmosphere is estimated for the first time.The water vapor level shows a high value from 23-29 June...Using observed wind and water vapor data from June 2006,water vapor exchange between the Rongbuk Valley and its above atmosphere is estimated for the first time.The water vapor level shows a high value from 23-29 June and a low from 12-21 June,which co-incide with the South Asian summer monsoon (SASM) active and break stages,respectively.The water vapor can be strongly injected into the closed region of the Rongbuk Valley from the outside atmosphere,with an average strength of 0.4 g s-1 m-2 in June 2006,given that no evaporation occurred.The air moisture exchange proc-esses can be greatly affected by the SASM evolution through changes in local radiation forcing.展开更多
For a better understanding of the air mass exchange processes between the surface and free atmos-phere in the Himalayas,a Himalayan exchange between the surface and troposphere 2007 (HEST2007) campaign was carried out...For a better understanding of the air mass exchange processes between the surface and free atmos-phere in the Himalayas,a Himalayan exchange between the surface and troposphere 2007 (HEST2007) campaign was carried out in the Rongbuk Valley,on the northern slope of Mt.Qomolangma,in June 2007.The wind,tem-perature and radiation conditions were measured during the campaign.Using these observation data,together with the National Centers for Environmental Prediction/the National Center for Atmospheric Research (NCEP/NCAR) reanalysis data,the air mass exchange between the inside of the valley and the outside of the valley is quantitatively estimated,based on a closed-valley method.The air mass is strongly injected into the Rongbuk Valley in the after-noon,which dominates the diurnal cycle,by a strong downward along-valley wind,with a maximum down-ward transfer rate of 9.4 cm s?1.The total air volume flux injected into the valley was 2.6×1011 m3 d?1 in 24 hours in June 2007,which is 15 times the total volume of the val-ley.The air mass transfer into the valley also exhibited a clear daily variation during the HEST2007 campaign,which can be affected by the synoptic situations through the adjustment of local radiation conditions.展开更多
In the summers of 2006 and 2007, the atmospheric CO2 concentration and the wind speed in the Rongbuk Valley on the northern slope of Mr. Everest were measured by an ultrasonic anemometer with an Li-7500 CO2/H2O gas an...In the summers of 2006 and 2007, the atmospheric CO2 concentration and the wind speed in the Rongbuk Valley on the northern slope of Mr. Everest were measured by an ultrasonic anemometer with an Li-7500 CO2/H2O gas analyzer. The average CO2 concentration was 370.23±0.59 and 367.45±1.91 ppm in June of 2006 and 2007, respectively. The values are much lower than those at sites with similar latitudes and altitudes worldwide. The observed atmospheric CO2 concentration in Rongbuk Valley can be affected by the transportation of prevailing down-valley winds from the up-valley direction to the observation site. Our results suggest that the Mt. Everest region could be ideal for background atmospheric and environmental studies.展开更多
文摘目的探讨急性缺血性脑卒中(AIS)患者血栓四项、凝血指标与患者神经功能损伤严重程度及短期预后的相关性。方法将2022年6月至2024年6月溧阳市人民医院收治的100例AIS患者纳入本次回顾性研究,依据入院时美国国立卫生研究院卒中量表(NIHSS)评分分成轻度组(n=28)、中度组(n=50)和重度组(n=22);根据出院后90 d mRS评分将患者分为预后良好组(n=72)和预后不良组(n=28)。比较不同神经功能损伤程度患者、不同预后患者的血栓四项[凝血酶-抗凝血酶复合物(TAT)、纤溶酶-α2纤溶酶抑制物复合物(PIC)、血栓调节蛋白(TM)、组织纤溶酶原激活物/纤溶酶原激活物抑制剂-1复合物(tPAI-C)]和凝血指标[活化部分凝血酶原时间(APTT)、凝血酶原时间(PT)、D-二聚体、纤维蛋白原(FIB)];用Spearman相关性分析血栓四项、凝血指标与NIHSS评分的相关性;并采用多因素Logistic回归分析法分析影响AIS患者的短期预后的因素。结果3组的APTT、PT比较,差异均无统计学意义(P>0.05);3组的D-二聚体和FIB比较,差异均有统计学意义(P<0.05),重度组的D-二聚体、FIB分别为(1.50±0.17)mg/L、(3.57±0.61)g/L,均显著高于中度组[(1.17±0.25)mg/L、(3.10±0.72)g/L]、轻度组[(0.69±0.12)mg/L、(2.75±0.56)g/L],中度组的D-二聚体、FIB均显著高于轻度组,差异均有统计学意义(P<0.05)。3组的TM、TAT、PIC和t-PAIC比较,差异均有统计学意义(P<0.05),重度组的TM、TAT、PIC和t-PAIC分别为(23.76±3.40)IU/mL、(42.80±4.33)ng/mL、(1.90±0.32)mg/L、(34.78±3.50)μg/L,均显著高于中度组[(17.50±3.27)IU/mL、(35.55±4.62)ng/mL、(1.58±0.24)mg/L、(25.51±4.12)μg/L]和轻度组[(12.61±2.34)IU/mL、(26.39±3.77)ng/mL、(1.15±0.13)mg/L、(18.44±3.13)μg/L],中度组的TM、TAT、PIC和t-PAIC均显著高于轻度组,差异均有统计学意义(P<0.05)。Spearman相关性分析显示,血浆D-二聚体、FIB、TM、TAT、PIC、t-PAIC与AIS患者的NIHSS评分均呈正相关(r=0.798、0.630、0.695、0.753、0.673、0.720,P<0.05)。相比于预后良好组,预后不良组的D-二聚体、FIB和血栓四项均显著升高,差异均有统计学意义(P<0.05)。Logistic回归分析显示,D-二聚体、FIB、血栓四项均为影响AIS短期预后的独立危险因素(P<0.05)。结论D-二聚体、FIB、血栓四项与AIS患者病情严重程度密切相关,也是AIS患者短期预后不良的危险因素。
基金Projects(51975061,51775055)supported by the National Natural Science Foundation of ChinaProject(2020JJ5599)supported by the Natural Science Foundation of Hunan Province,ChinaProjects(19C0032,19B033)supported by the Research Foundation of Education Bureau of Hunan Province,China。
文摘The expanding of material library of laser powder bed fusion(L-PBF)is of great significance to the development of material science.In this study,the biomedical Ti-13Nb-13Zr powder was mixed with the tantalum particles(2 wt%−8 wt%)and fabricated by L-PBF.The microstructure consists of aβmatrix with partially unmelted pure tantalum distributed along the boundaries of molten pool owing to the Marangoni convention.Because the melting process of Ta absorbs lots of energy,the size of molten pool becomes smaller with the increase of Ta content.The fine microstructure exists in the center of melt pool while coarse microstructure is on the boundaries of melt pool because of the existence of heat-affected zone.The columnar-to-equiaxed transitions(CETs)happen in the zones near the unmelted Ta,and the low lattice mismatch induced by solid Ta phase is responsible for this phenomenon.The recrystallization texture is strengthened while the fiber texture is weakened when the tantalum content is increased.Due to the formation of refined martensiteα′grains during L-PBF,the compressive strengths of L-PBF-processed samples are higher than those fabricated by traditional processing technologies.The present research will provide an important reference for biomedical alloy design via L-PBF process in the future.
基金supported by the Special Fund for Meteorological Research in the Public Interest (GYHY2012 06041)the National Natural Science Foundation of China (Grant No.40905067)and the Ministry of Science and Technology of the People’s Republic of China (2009CB421403)
文摘Previous studies have shown that reanalysis products contain large uncertainties in the Tibetan Plateau(TP),and the biases are location dependent.Therefore,these products must be evaluated with in situ observations prior to their applications.In this study,the authors compare the results of several reanalysis projects with independent sounding observations recorded in the Yarlung Tsangpo River valley in the Eastern Himalayas in June 2010.These reanalysis projects include Climate Forecast System Reanalysis(CFSR),Interim European Centre for Medium Range Weather Forecasts Reanalysis(ERA- Interim),Japanese 25-year Reanalysis(JRA-25),Modern Era Retrospective Analysis for Research and Applications(MERRA),National Center for Environmental Prediction and the Department of Energy Reanalysis 2(NCEP-R2),and NCEP Final Analysis(FNL).Statistical quantities such as average,mean bias(MB),root-mean-square difference(RMSD),and correlation coefficient(R) of temperature,specific humidity,u-wind,and v-wind between 100 hPa and 650 hPa were calculated.The authors determined that the performance of each product differed with variables at different levels.The average profiles of the variables were captured by the reanalysis products,with large biases appearing at lower levels.ERA-Interim and NCEP-R2 showed the best and worst performances,respectively,for all variables.This study suggests that users should select appropriate reanalysis products according to their specific purposes for TP research.
基金supported by the Special Fund for Meteorological Research in the Public Interest[grant number GYHY201206041]the projects entitled‘Comprehensive Evaluation of Polar Areas in Global and Regional Climate Changes’[grant number CHINARE2015–2019]‘Polar Environment Comprehensive Investigation and Assessment’[grant number CHINARE2015–2019]
文摘To investigate the impacts of the quasi-biennial oscillation （QBO） on high-latitude circulation and the Arctic vortex, stratospheric zonal wind at 55-65°N is analyzed. The seasonal cycle, solar cycle, and linear trend in the zonal wind at these latitudes are analyzed and removed, and the QBO signal is retrieved from the monthly zonal wind for the period 1979-2014. The zonal wind has a strong decreasing trend in winter, with a maximum decrease （less than -0.35 m s-1 yr-1） occurring within 70-100°E. The zonal wind has an in-phase response of 1.6 m s-1 to the solar cycle, with a maximum within 100-140°E. A clear QBO signal is detected in the zonal wind during the period 1979-2014, with an amplitude of 2.5 m s-1 and a period of 30 months. The latitudinal distribution of the QBO signal is inhomogeneous, with a maximum within 120-180°E and a minimum within 25-45°E.
基金financed by the National Natural Science Foundation of China (Grant No.40533018)the Ministry of Science and Technology of the People’s Republic of China(Grant No.2009CB421403)the Chinese Academy of Sciences(Grants No.KZCX3-SW-231 and 8-070203)
文摘Using observed wind and water vapor data from June 2006,water vapor exchange between the Rongbuk Valley and its above atmosphere is estimated for the first time.The water vapor level shows a high value from 23-29 June and a low from 12-21 June,which co-incide with the South Asian summer monsoon (SASM) active and break stages,respectively.The water vapor can be strongly injected into the closed region of the Rongbuk Valley from the outside atmosphere,with an average strength of 0.4 g s-1 m-2 in June 2006,given that no evaporation occurred.The air moisture exchange proc-esses can be greatly affected by the SASM evolution through changes in local radiation forcing.
基金financed by the National Natural Science Foundation of China (Grant No.40533018)the Ministry of Science and Technology of the People’s Republic of China (Grant No.2009CB421403)the Chinese Academy of Sciences (Grant Nos.KZCX3-SW-231 and 8-070203)
文摘For a better understanding of the air mass exchange processes between the surface and free atmos-phere in the Himalayas,a Himalayan exchange between the surface and troposphere 2007 (HEST2007) campaign was carried out in the Rongbuk Valley,on the northern slope of Mt.Qomolangma,in June 2007.The wind,tem-perature and radiation conditions were measured during the campaign.Using these observation data,together with the National Centers for Environmental Prediction/the National Center for Atmospheric Research (NCEP/NCAR) reanalysis data,the air mass exchange between the inside of the valley and the outside of the valley is quantitatively estimated,based on a closed-valley method.The air mass is strongly injected into the Rongbuk Valley in the after-noon,which dominates the diurnal cycle,by a strong downward along-valley wind,with a maximum down-ward transfer rate of 9.4 cm s?1.The total air volume flux injected into the valley was 2.6×1011 m3 d?1 in 24 hours in June 2007,which is 15 times the total volume of the val-ley.The air mass transfer into the valley also exhibited a clear daily variation during the HEST2007 campaign,which can be affected by the synoptic situations through the adjustment of local radiation conditions.
基金financed by the Chinese Academy of Sciences(Grant No.KZCX2-YW-Q11-01)the National Basic Research Program of China(Grant No.2009CB421403)
文摘In the summers of 2006 and 2007, the atmospheric CO2 concentration and the wind speed in the Rongbuk Valley on the northern slope of Mr. Everest were measured by an ultrasonic anemometer with an Li-7500 CO2/H2O gas analyzer. The average CO2 concentration was 370.23±0.59 and 367.45±1.91 ppm in June of 2006 and 2007, respectively. The values are much lower than those at sites with similar latitudes and altitudes worldwide. The observed atmospheric CO2 concentration in Rongbuk Valley can be affected by the transportation of prevailing down-valley winds from the up-valley direction to the observation site. Our results suggest that the Mt. Everest region could be ideal for background atmospheric and environmental studies.
