An Ms6.4 earthquake occurred in the Menyuan county of Qinghai Province on Jan 21, 2016. In order to recognize the development of horizontal deformation and distinguish precursory deformation anomalies, we obtained coo...An Ms6.4 earthquake occurred in the Menyuan county of Qinghai Province on Jan 21, 2016. In order to recognize the development of horizontal deformation and distinguish precursory deformation anomalies, we obtained coordinates time series, velocity and strain model around the seismic zones from processing of continuous observations from 2010 and 6 times of surveying Global Positioning System （GPS） data since 2009. The results show that, before the earthquake, the eastern segmentation of the Qilian tectonic zone where the Lenglongling Fault located is in strong crustal shortening and compressional strain state with dilatational rates of -15 to -25 ppb. The Lenglongling Fault has a strike-slip rate of 3.1 mm/a and a far-field differential orthogonal rate of 7 mm/a, while differential rate is only 1.2 mm/a near the fault, which reflects its locking feature with strain energy accumulation and high seismic risks. Dynamic evolution of deformation model shows that preevent dilatational rates around the seismic zones increases from 15 ppb/a to -20 ppb/a with its center moving to the source areas. Time series of N components of G337 station, which is 13.7 km away from the Lenglongling Fault, exhibit a 5 mm/a acceleration anomaly. Time series of base-station QHME （in Menyuan） displays a reverse acceleration from the end of Sep. to Dec., 2016 when it comes to a largest deviation, and the accumulative displacement is more than 4 mm and the value reverse till the earthquake. In our results, coseismic displacement of N, E, U components in QHME site are 3.0 mm, 3.0 mm, -5.4 mm, respectively. If we profile these values onto the Lenglongling Fault, we can achieve a 1.1 mm of strike slip and 4.1 mm updip slip relative to the hanging wall.展开更多
文摘目的:应用三维斑点追踪技术(three dimensional speckle tracking imaging,3D-STI)获取冠心病患者行经皮冠状动脉介入治疗(percutaneous coronary intervention,PCI)前后左室整体面积应变(global area strain,GAS)参数,并探讨面积应变参数预测PCI术后患者心功能改善的临床应用价值。方法:选取拟行PCI术的42例冠心病患者,分别于术前及术后6个月行常规三维超声心动图及3D-STI检查,记录左室舒张末期容积(end-diastolic volume,EDV)、左室收缩末期容积(end-systolic volume,ESV)、左室射血分数(left ventricular eject fraction,LVEF)、左室GAS值及PCI前后左室射血分数改变量(ΔLVEF)。根据PCI术后LVEF提高率是否≥5%将患者分为心功能改善组与未改善组,比较两组间各参数的差异并探讨面积应变参数与心功能改善间的相关性。结果:PCI术前与术后患者EDV,LVEF,ESV,LVEF,肌钙蛋白含量及GAS差异均无统计学意义(P>0.05)。与未改善组比较,改善组LVEF[(54.9±4.9)% vs (44.3±5.7)%,P<0.001],GAS[(?31.9±5.8)%vs (?26.0±5.9)%,P=0.003]均明显增高,但肌钙蛋白含量[(1.9±2.0)μg/L vs (4.0±3.4)μg/L]及ESV[(50.6±6.7) mL vs (63.2±10.9) mL]降低。冠心病患者PCI术前GAS与ΔLVEF呈正相关(r=0.58,P<0.001)。以术前GAS预测冠心病患者PCI术后心功能改善(LVEF提高率≥5%)的ROC曲线下面积为0.93,以GAS=28.9%为最佳截断点时敏感度为86.7%,特异度为88.9%。多元线性回归曲线结果显示:GAS(β=?0.73,P<0.001)可作为心功能改善的预测因素。结论:基于3D-STI的面积应变参数与PCI术后患者心功能改变相关,可用于预测冠心病患者PCI术后疗效。
基金support by National Natural Science Foundation of China(51479163,41174083)
文摘An Ms6.4 earthquake occurred in the Menyuan county of Qinghai Province on Jan 21, 2016. In order to recognize the development of horizontal deformation and distinguish precursory deformation anomalies, we obtained coordinates time series, velocity and strain model around the seismic zones from processing of continuous observations from 2010 and 6 times of surveying Global Positioning System （GPS） data since 2009. The results show that, before the earthquake, the eastern segmentation of the Qilian tectonic zone where the Lenglongling Fault located is in strong crustal shortening and compressional strain state with dilatational rates of -15 to -25 ppb. The Lenglongling Fault has a strike-slip rate of 3.1 mm/a and a far-field differential orthogonal rate of 7 mm/a, while differential rate is only 1.2 mm/a near the fault, which reflects its locking feature with strain energy accumulation and high seismic risks. Dynamic evolution of deformation model shows that preevent dilatational rates around the seismic zones increases from 15 ppb/a to -20 ppb/a with its center moving to the source areas. Time series of N components of G337 station, which is 13.7 km away from the Lenglongling Fault, exhibit a 5 mm/a acceleration anomaly. Time series of base-station QHME （in Menyuan） displays a reverse acceleration from the end of Sep. to Dec., 2016 when it comes to a largest deviation, and the accumulative displacement is more than 4 mm and the value reverse till the earthquake. In our results, coseismic displacement of N, E, U components in QHME site are 3.0 mm, 3.0 mm, -5.4 mm, respectively. If we profile these values onto the Lenglongling Fault, we can achieve a 1.1 mm of strike slip and 4.1 mm updip slip relative to the hanging wall.
