The Red River Fault Zone is a gigantic slide-slip fault zone extending up to 1000km from Tibet to SouthChina Sea. It has been divided into the north, central and south segments according to the difference of thegeomet...The Red River Fault Zone is a gigantic slide-slip fault zone extending up to 1000km from Tibet to SouthChina Sea. It has been divided into the north, central and south segments according to the difference of thegeometry, kinetics, and seismicity on the land, but according to the contacted relationship between the old pre-Cenozoic block in Indochina Peninsula and the South China block, the Red River Fault Zone was divided into two parts extending from land to ocean, the north and south segments. Since the Tertiary, the Red River Fault Zone suffered first the sinistral movement and then the dextral movement. The activities of the north and the south segments were different. Based on the analysis of earthquakes and focal mechanism solutions,earthquakes with the focus depths of 0-33km are distributed over the whole region and more deep earthquakes are distributed on the northeastern sides of the Red River fault. Types of faulting activities are the thrust in the northwest, the normal in the north and the strike-slip in the south, with the odd type, viz. the transition type, in the other region. These show the Red River Fault Zone and its adjacent region suffered the extruding force in NNW direction and the normal stress in NEE direction and it makes the fault in the region extrude-thrust,horizontal strike-slip and extensional normal movement.展开更多
缅甸作为全球受地震灾害影响甚为严重的国家之一,因缺乏区域地震观测资料,对其孕震构造环境的详细分析研究十分不足.本文利用中缅联合地球物理探测(CMGSMO)项目在缅甸布设的密集宽频带地震台阵观测数据,对印缅山脉至中央盆地的地震活动...缅甸作为全球受地震灾害影响甚为严重的国家之一,因缺乏区域地震观测资料,对其孕震构造环境的详细分析研究十分不足.本文利用中缅联合地球物理探测(CMGSMO)项目在缅甸布设的密集宽频带地震台阵观测数据,对印缅山脉至中央盆地的地震活动特征进行了分析.基于改进的剪切-粘贴法(generalized Cut And Paste,gCAP)新获得了28个ML3.0~5.0地震事件的震源机制解等震源参数信息,并结合全球矩心矩张量(Global Centroid Moment Tensor,GCMT)目录及其他已发表的震源机制解资料,应用区域阻尼应力场反演算法得到了研究区的应力分布状态,综合探讨了研究区域深浅部构造关系及孕震机制.研究表明印度板块持续的斜向俯冲控制着印缅山脉和中央盆地的地震活动,但其影响向东逐渐减弱,浅部最大主应力方向的变化可能反映的是局部应力集中或者是相对短时间内的应力调整,不同区域的地震活动差异主要受区域构造及其浅部断层的影响,中央盆地下方的两个邻区之间的最大主应力轴的偏转可能与深部活动相关.展开更多
目的探讨基于前列腺影像报告和数据系统(prostate imaging reporting and data system,PI-RADS)V2.1版的动态对比增强磁共振成像(dynamic contrast enhanced magnetic resonance imaging,DCE-MRI)定量值对外周带前列腺癌(prostate cance...目的探讨基于前列腺影像报告和数据系统(prostate imaging reporting and data system,PI-RADS)V2.1版的动态对比增强磁共振成像(dynamic contrast enhanced magnetic resonance imaging,DCE-MRI)定量值对外周带前列腺癌(prostate cancer,PCa)和局灶性慢性前列腺炎(chronic prostatitis,CP)的鉴别价值。材料与方法回顾性分析2022年1月至2023年4月期间芜湖市第二人民医院收治的57例外周带PCa患者(研究组)和21例局灶性CP患者(对照组),所有患者接受T2WI、扩散加权成像(diffusion weighted imaging,DWI)、DCE-MRI检查,比较两组双参数(bi-parameter,bp)-MRI(T2WI+DWI)、多参数(multi-parameter,mp)-MRI(T2WI+DWI+DCE-MRI)扫描方案的PI-RADS V2.1评分、DCE-MRI扫描定量值,采用受试者工作特征(receiver operating characteristic,ROC)曲线评估各诊断方案对外周带PCa的诊断价值。结果研究组bp-MRI、mp-MRI扫描方案PI-RADS V2.1评分分别为(4.12±0.88)、(4.31±0.70)分,分别高于对照组的(2.42±1.14)、(2.52±1.22)分,P<0.05。研究组DCE-MRI定量值容积转运常数(volume transport constant,K^(trans))、速率常数(rate constant,K_(ep))均高于对照组(P<0.001),两组血管外细胞外间隙容积分数(extravascular extracellular volume fraction,V_(e))比较差异无统计学意义(P>0.05)。ROC分析显示,bp-MRI、mp-MRI、K^(trans)、K_(ep)诊断外周带PCa的ROC曲线下面积(area under the curve,AUC)[95%置信区间(confidenceinterval,CI)]分别为0.780(0.672~0.866)、0.857(0.759~0.926)、0.734(0.622~0.828)、0.818(0.716~0.896),mp-MRI诊断效能较bp-MRI稍高(P<0.05),其余各项比较差异无统计学意义(P>0.05)。采用logit(p)法建立ROC拟合诊断模型,结果显示K_(ep)+K^(trans)、mp-MRI+K^(trans)、mp-MRI+K_(ep)对外周带PCa诊断效能差异均无统计学意义(P>0.05);K_(ep)+K^(trans)的诊断效能与bp-MRI、mp-MRI、K^(trans)、K_(ep)比较差异均无统计学意义(P>0.05);mp-MRI+K^(trans)的诊断效能分别高于bp-MRI、mp-MRI、K_(ep)、K^(trans)(P<0.05);mp-MRI+K_(ep)的诊断效能分别高于bp-MRI、K^(trans)(P<0.05)。结论基于PI-RADS V2.1 mp-MRI、bp-MRI与DCE-MRI定量值K^(trans)、K_(ep)对外周带PCa与局灶性CP的鉴别诊断效能相当,且两定量参数联合,或分别与mp-MRI联合能有效提高诊断效能,能够为临床不同适应症患者的诊断提供更多选择。展开更多
The seismicity of Longrnenshan fault zone and its vicinities before the 12 May 2008 Wenchuan Ms8.0 earthquake is studied. Based on the digital seismic waveform data observed from regional seismic networks and mobile s...The seismicity of Longrnenshan fault zone and its vicinities before the 12 May 2008 Wenchuan Ms8.0 earthquake is studied. Based on the digital seismic waveform data observed from regional seismic networks and mobile stations, the focal mechanism solutions are determined. Our analysis results show that the seismicities of Longmenshan fault zone before the 12 May 2008 Wenchuan earthquake were in stable state. No obvious phenomena of seismic activity intensifying appeared. According to focal mechanism solutions of some small earthquakes before the 12 May 2008 Wenchuan earthquake, the direction of principal compressive stress P-axis is WNW-ESE. The two hypocenter fault planes are NE-striking and NW-striking. The plane of NE direction is among N50°-70°E, the dip angles of fault planes are 60°-70° and it is very steep. The faultings of most earthquakes are dominantly characterized by dip-slip reverse and small part of faultings present strike-slip. The azimuths of principal compressive stress, the strikes of source fault planes and the dislocation types calculated from some small earthquakes before the 12 May 2008 Wenchuan earthquake are in accordance with that of the main shock. The average stress field of micro-rupture along the Longmenshan fault zone before the great earthquake is also consistent with that calculated from main shock. Zipingpu dam is located in the east side 20 km from the initial rupture area of the 12 May 2008 Wenchuan earthquake. The activity increment of small earthquakes in the Zipingpu dam is in the period of water discharging. The source parameter results of the small earthquakes which occurred near the initial rupture area of the 12 May 2008 Wenchuan earthquake indicate that the focal depths are 5 to 14 km and the source parameters are identical with that of earthquake.展开更多
We estimate the focal depths and fault plane solutions of 46 moderate earthquakes in the Himalayan- Tibetan region by modeling the broadband waveforms of teleseismic P waves. The depths of 38 of these earth- quakes ra...We estimate the focal depths and fault plane solutions of 46 moderate earthquakes in the Himalayan- Tibetan region by modeling the broadband waveforms of teleseismic P waves. The depths of 38 of these earth- quakes range between 0-40 km, with a peak at -5 km. One earthquake is located within the lower crust of the Indian shield. The remaining eight earthquakes occurred between depths of 80 -120 km and are all located in the Pamir-Hindu Kush and the Indo-Myanmar deep seismic zones. None of the earthquakes outside these deep seismic zones are located in the mantle. Global centroid moment tensor （CMT） solutions indicate that most earthquakes in northern Tibet and northern India had thrust-faulting mechanisms and that normal and strike-slip faulting earthquakes occurred primarily in central Tibet. These mechanisms are consistent with the predominantly NNW-SSE compression in the direction of current Himalayan-Tibetan continental collision.展开更多
Objective Ependymal cells are thought to be the primary source of neural stem cells in the adult central nervous system. The purpose of this study is to examine spatial and temporal profiles of ependymal cell prolife...Objective Ependymal cells are thought to be the primary source of neural stem cells in the adult central nervous system. The purpose of this study is to examine spatial and temporal profiles of ependymal cell proliferation and migration after focal cerebral ischemia. Methods Eighty male Sprague Dawley rats underwent permanent middle cerebral artery occlusion after injection of 10 μL of 0.2% Dil into the lateral ventricle. Rats were sacrificed and brain sections were acquired for pathological evaluation and laser confocal imaging at day 1,3,7,11,14,21 and 28 after ischemia. Results The density of Dil-labeled cells in the ischemic ipsilateral subventricular zone was significantly higher than that in the control group and these labeled cells dispersed in the ischemic ipsilateral subventricular zone and/or were located in ependyma from day 1 to 11. In the ischemic ipsilateral cortex, some Dil-labeled cells occurred in peri-infarction and infarction of parietal region at day14 and peaked at day 21 when some Dil-labeled cell nodules were found in this region. During postischemic day 14-28, a significant decrease in labeled cell density in the ischemic ipsilateral subventricular zone was coincident with a significant increase in labeled cells density in the cortex (peri-infarction and infarction). Conclusion The results indicate that ependymal cells proliferate and migrate after focal cerebral ischemia in the adult rat brain.展开更多
基金supported by the Chinese Academy of Sciences(Project No.KZCX2-209-01)National Science Foundation(Project No.40276015)Guangdong Province Science Foundation(Project No.021561).
文摘The Red River Fault Zone is a gigantic slide-slip fault zone extending up to 1000km from Tibet to SouthChina Sea. It has been divided into the north, central and south segments according to the difference of thegeometry, kinetics, and seismicity on the land, but according to the contacted relationship between the old pre-Cenozoic block in Indochina Peninsula and the South China block, the Red River Fault Zone was divided into two parts extending from land to ocean, the north and south segments. Since the Tertiary, the Red River Fault Zone suffered first the sinistral movement and then the dextral movement. The activities of the north and the south segments were different. Based on the analysis of earthquakes and focal mechanism solutions,earthquakes with the focus depths of 0-33km are distributed over the whole region and more deep earthquakes are distributed on the northeastern sides of the Red River fault. Types of faulting activities are the thrust in the northwest, the normal in the north and the strike-slip in the south, with the odd type, viz. the transition type, in the other region. These show the Red River Fault Zone and its adjacent region suffered the extruding force in NNW direction and the normal stress in NEE direction and it makes the fault in the region extrude-thrust,horizontal strike-slip and extensional normal movement.
文摘缅甸作为全球受地震灾害影响甚为严重的国家之一,因缺乏区域地震观测资料,对其孕震构造环境的详细分析研究十分不足.本文利用中缅联合地球物理探测(CMGSMO)项目在缅甸布设的密集宽频带地震台阵观测数据,对印缅山脉至中央盆地的地震活动特征进行了分析.基于改进的剪切-粘贴法(generalized Cut And Paste,gCAP)新获得了28个ML3.0~5.0地震事件的震源机制解等震源参数信息,并结合全球矩心矩张量(Global Centroid Moment Tensor,GCMT)目录及其他已发表的震源机制解资料,应用区域阻尼应力场反演算法得到了研究区的应力分布状态,综合探讨了研究区域深浅部构造关系及孕震机制.研究表明印度板块持续的斜向俯冲控制着印缅山脉和中央盆地的地震活动,但其影响向东逐渐减弱,浅部最大主应力方向的变化可能反映的是局部应力集中或者是相对短时间内的应力调整,不同区域的地震活动差异主要受区域构造及其浅部断层的影响,中央盆地下方的两个邻区之间的最大主应力轴的偏转可能与深部活动相关.
文摘目的探讨基于前列腺影像报告和数据系统(prostate imaging reporting and data system,PI-RADS)V2.1版的动态对比增强磁共振成像(dynamic contrast enhanced magnetic resonance imaging,DCE-MRI)定量值对外周带前列腺癌(prostate cancer,PCa)和局灶性慢性前列腺炎(chronic prostatitis,CP)的鉴别价值。材料与方法回顾性分析2022年1月至2023年4月期间芜湖市第二人民医院收治的57例外周带PCa患者(研究组)和21例局灶性CP患者(对照组),所有患者接受T2WI、扩散加权成像(diffusion weighted imaging,DWI)、DCE-MRI检查,比较两组双参数(bi-parameter,bp)-MRI(T2WI+DWI)、多参数(multi-parameter,mp)-MRI(T2WI+DWI+DCE-MRI)扫描方案的PI-RADS V2.1评分、DCE-MRI扫描定量值,采用受试者工作特征(receiver operating characteristic,ROC)曲线评估各诊断方案对外周带PCa的诊断价值。结果研究组bp-MRI、mp-MRI扫描方案PI-RADS V2.1评分分别为(4.12±0.88)、(4.31±0.70)分,分别高于对照组的(2.42±1.14)、(2.52±1.22)分,P<0.05。研究组DCE-MRI定量值容积转运常数(volume transport constant,K^(trans))、速率常数(rate constant,K_(ep))均高于对照组(P<0.001),两组血管外细胞外间隙容积分数(extravascular extracellular volume fraction,V_(e))比较差异无统计学意义(P>0.05)。ROC分析显示,bp-MRI、mp-MRI、K^(trans)、K_(ep)诊断外周带PCa的ROC曲线下面积(area under the curve,AUC)[95%置信区间(confidenceinterval,CI)]分别为0.780(0.672~0.866)、0.857(0.759~0.926)、0.734(0.622~0.828)、0.818(0.716~0.896),mp-MRI诊断效能较bp-MRI稍高(P<0.05),其余各项比较差异无统计学意义(P>0.05)。采用logit(p)法建立ROC拟合诊断模型,结果显示K_(ep)+K^(trans)、mp-MRI+K^(trans)、mp-MRI+K_(ep)对外周带PCa诊断效能差异均无统计学意义(P>0.05);K_(ep)+K^(trans)的诊断效能与bp-MRI、mp-MRI、K^(trans)、K_(ep)比较差异均无统计学意义(P>0.05);mp-MRI+K^(trans)的诊断效能分别高于bp-MRI、mp-MRI、K_(ep)、K^(trans)(P<0.05);mp-MRI+K_(ep)的诊断效能分别高于bp-MRI、K^(trans)(P<0.05)。结论基于PI-RADS V2.1 mp-MRI、bp-MRI与DCE-MRI定量值K^(trans)、K_(ep)对外周带PCa与局灶性CP的鉴别诊断效能相当,且两定量参数联合,或分别与mp-MRI联合能有效提高诊断效能,能够为临床不同适应症患者的诊断提供更多选择。
基金supported by National Key Basic Research 973bNational Scientific technology support plan (2006BAC01B02-01-01).
文摘The seismicity of Longrnenshan fault zone and its vicinities before the 12 May 2008 Wenchuan Ms8.0 earthquake is studied. Based on the digital seismic waveform data observed from regional seismic networks and mobile stations, the focal mechanism solutions are determined. Our analysis results show that the seismicities of Longmenshan fault zone before the 12 May 2008 Wenchuan earthquake were in stable state. No obvious phenomena of seismic activity intensifying appeared. According to focal mechanism solutions of some small earthquakes before the 12 May 2008 Wenchuan earthquake, the direction of principal compressive stress P-axis is WNW-ESE. The two hypocenter fault planes are NE-striking and NW-striking. The plane of NE direction is among N50°-70°E, the dip angles of fault planes are 60°-70° and it is very steep. The faultings of most earthquakes are dominantly characterized by dip-slip reverse and small part of faultings present strike-slip. The azimuths of principal compressive stress, the strikes of source fault planes and the dislocation types calculated from some small earthquakes before the 12 May 2008 Wenchuan earthquake are in accordance with that of the main shock. The average stress field of micro-rupture along the Longmenshan fault zone before the great earthquake is also consistent with that calculated from main shock. Zipingpu dam is located in the east side 20 km from the initial rupture area of the 12 May 2008 Wenchuan earthquake. The activity increment of small earthquakes in the Zipingpu dam is in the period of water discharging. The source parameter results of the small earthquakes which occurred near the initial rupture area of the 12 May 2008 Wenchuan earthquake indicate that the focal depths are 5 to 14 km and the source parameters are identical with that of earthquake.
基金funded by the grants of 100-talent program of Chinese Academy of Sciencesto L. Baithe US National Science Foundation (EAR-0944167) to J. Ritsemathe National Natural Science Foundation of China (40930317) to J. Zhao
文摘We estimate the focal depths and fault plane solutions of 46 moderate earthquakes in the Himalayan- Tibetan region by modeling the broadband waveforms of teleseismic P waves. The depths of 38 of these earth- quakes range between 0-40 km, with a peak at -5 km. One earthquake is located within the lower crust of the Indian shield. The remaining eight earthquakes occurred between depths of 80 -120 km and are all located in the Pamir-Hindu Kush and the Indo-Myanmar deep seismic zones. None of the earthquakes outside these deep seismic zones are located in the mantle. Global centroid moment tensor （CMT） solutions indicate that most earthquakes in northern Tibet and northern India had thrust-faulting mechanisms and that normal and strike-slip faulting earthquakes occurred primarily in central Tibet. These mechanisms are consistent with the predominantly NNW-SSE compression in the direction of current Himalayan-Tibetan continental collision.
文摘Objective Ependymal cells are thought to be the primary source of neural stem cells in the adult central nervous system. The purpose of this study is to examine spatial and temporal profiles of ependymal cell proliferation and migration after focal cerebral ischemia. Methods Eighty male Sprague Dawley rats underwent permanent middle cerebral artery occlusion after injection of 10 μL of 0.2% Dil into the lateral ventricle. Rats were sacrificed and brain sections were acquired for pathological evaluation and laser confocal imaging at day 1,3,7,11,14,21 and 28 after ischemia. Results The density of Dil-labeled cells in the ischemic ipsilateral subventricular zone was significantly higher than that in the control group and these labeled cells dispersed in the ischemic ipsilateral subventricular zone and/or were located in ependyma from day 1 to 11. In the ischemic ipsilateral cortex, some Dil-labeled cells occurred in peri-infarction and infarction of parietal region at day14 and peaked at day 21 when some Dil-labeled cell nodules were found in this region. During postischemic day 14-28, a significant decrease in labeled cell density in the ischemic ipsilateral subventricular zone was coincident with a significant increase in labeled cells density in the cortex (peri-infarction and infarction). Conclusion The results indicate that ependymal cells proliferate and migrate after focal cerebral ischemia in the adult rat brain.
