As an important indicator parameter of fluid identification,fluid factor has always been a concern for scholars.However,when predicting Russell fluid factor or effective pore-fluid bulk modulus,it is necessary to intr...As an important indicator parameter of fluid identification,fluid factor has always been a concern for scholars.However,when predicting Russell fluid factor or effective pore-fluid bulk modulus,it is necessary to introduce a new rock skeleton parameter which is the dry-rock VP/VS ratio squared(DVRS).In the process of fluid factor calculation or inversion,the existing methods take this parameter as a static constant,which has been estimated in advance,and then apply it to the fluid factor calculation and inversion.The fluid identification analysis based on a portion of the Marmousi 2 model and numerical forward modeling test show that,taking the DVRS as a static constant will limit the identification ability of fluid factor and reduce the inversion accuracy.To solve the above problems,we proposed a new method to regard the DVRS as a dynamic variable varying with depth and lithology for the first time,then apply it to fluid factor calculation and inversion.Firstly,the exact Zoeppritz equations are rewritten into a new form containing the fluid factor and DVRS of upper and lower layers.Next,the new equations are applied to the four parameters simultaneous inversion based on the generalized nonlinear inversion(GNI)method.The testing results on a portion of the Marmousi 2 model and field data show that dynamic DVRS can significantly improve the fluid factor identification ability,effectively suppress illusion.Both synthetic and filed data tests also demonstrate that the GNI method based on Bayesian deterministic inversion(BDI)theory can successfully solve the above four parameter simultaneous inversion problem,and taking the dynamic DVRS as a target inversion parameter can effectively improve the inversion accuracy of fluid factor.All these results completely verified the feasibility and effectiveness of the proposed method.展开更多
Geothermal resources are a promising approach to clean renewable energy;90%of them are deep reservoirs of hot dry rock that require hydraulic fracturing to create a network of connections among wells to enable efficie...Geothermal resources are a promising approach to clean renewable energy;90%of them are deep reservoirs of hot dry rock that require hydraulic fracturing to create a network of connections among wells to enable efficient heat exchange,known as an Enhanced Geothermal System(EGS).The Pohang EGS project in south Korea led to a devasting Mw5.5 earthquake,triggered by the reservoir's EGS stimulation,the largest earthquake known to have been induced by EGS development.Detailed investigations have been conducted to understand the cause of the Pohang earthquake;the conclusion has been that overpressurized injected fluids migrated into an unknown fault triggering this large earthquake.Detailed velocity images for the source zone of the 2017 Pohang earthquake,which could be helpful for further understanding its inducing mechanism,are unavailable.However,we have assembled detailed aftershock data recorded by 41 local stations installed within about three months after the Mw5.5 Pohang earthquake,and have then applied the V_(p)/V_(s)model's consistency-constrained double-difference seismic tomography method to determine the high-resolution three-dimensional Vp(compressional wave velocity),Vs(shear wave velocity),and V_(p)/V_(s)models of the source region that we report here,as well as earthquake locations within the source region.The velocity images reveal that the deep source area of the 2017 Pohang earthquake is dominated by low Vp,high Vs,and low V_(p)/V_(s)anomalies,a pattern that can be caused by overpressurized vapors due to high temperatures at these depths.Based on aftershock locations and velocity features,our studies support the conclusion that the 2017Pohang earthquake was triggered by injected EGS fluids that migrated into a blind fault.展开更多
The Hi-CLIMB seismic array is located in the central-western Tibetan Plateau.The H-κ-c method(Li JT et al.,2019)was applied to receiver function data on the HiCLIMB,which corrects the back-azimuthal variations in the...The Hi-CLIMB seismic array is located in the central-western Tibetan Plateau.The H-κ-c method(Li JT et al.,2019)was applied to receiver function data on the HiCLIMB,which corrects the back-azimuthal variations in the arrival times of Ps and crustal multiples caused by crustal anisotropy and dipping interfaces before performing H-κstacking.Compared to the traditional H-κmethod,the H-κstacking results after harmonic corrections showed considerable improvements,including greatly reduced errors,significantly less scattered H(crustal thickness)andκ(crustal v_(P)/v_(S)ratio)values,and clearer patterns of H andκin different Tibetan blocks.This demonstrates that the H-κ-c method works well even for regions with complex crustal structures,such as the Tibetan Plateau,when there are helpful references from nearby stations or other constraints.The variation in crustal thickness agrees with previous studies but tends to be relatively shallower beneath most of the plateau.Two regions with particularly high crustal v_(P)/v_(S)were observed,namely,one in the northern Himalaya block and beneath the YarlungZangbo suture,and the other in the Qiangtang block.Their correlation with mid-crust low S velocities from previous studies suggests the possible presence of fluid or partial melt in the two regions,which may have implications for the crustal flow model.In contrast,the Lhasa block had relatively lower crustal v_(P)/v_(S)and relatively higher crustal S velocity within the plateau,which is interpreted to be mechanically stronger than the Himalaya and Qiangtang blocks,and without mid-crust partial melt.展开更多
The North China Craton(NCC)is one of the oldest cratons on earth.Several important tectonic transformations of MesozoicCenozoic tectonic regime led to the destruction of the North China craton.The knowledge of crustal...The North China Craton(NCC)is one of the oldest cratons on earth.Several important tectonic transformations of MesozoicCenozoic tectonic regime led to the destruction of the North China craton.The knowledge of crustal structure can provide important constraints for the formation and evolution of cratons.New maps of sediment thickness,crustal thickness(H)and v_(P)/v_(S)(κ)in the central and western NCC were obtained using sequential H-κstacking.P-wave receiver functions are calculated using teleseismic waveform data recorded by 405 stations from Chin Array project.Benefiting from the densely distribution of temporary seismic stations,our results reveal details of the crustal structure in the study area.The thickness of sedimentary layer in North China ranges from 0–6.4 km,and the thickest sedimentary layer is in Ordos block and its surroundings(about 2.8–6 km);The thickness of sedimentary layer in the Mongolia fold belt and Yinshan orogenic belt is relatively thin(less than 1 km).The crustal thickness of the study area varies between 27–48 km,of which the crust of the North China Plain is about 30–33 km,the central NCC is about 33–40 km,and the Ordos block is 40–48 km thick.The average v_(P)/v_(S)ratios in the study area is mostly between 1.66 and 1.90,and that in the Yanshan-Taihang mountain fold belt is between 1.70 and 1.85,and that in the Ordos block is between 1.65 and 1.90,with an average value of 1.77,indicating the absence of a thick basaltic lower crust.The obvious negative correlation between crustal thickness and average v_(P)/v_(S)ratio within Ordos and Central Asia orogenic belt may be related to magmatic underplating during the crustal formation.There is no significant correlation between the crustal thickness and the v_(P)/v_(S)ratio in the Lüliang-Taihang mountain fold belt,which may be related to the multiple geological processes such as underplating and crustal extension and thinning in this area.The lack of correlation between crust thickness and topography in the central orogenic belt and the North China Basin indicates the topography of these areas are controlled not only by crustal isostatic adjustment but also by the lithospheric mantle processes.展开更多
[目的]研究术前心电图V1导联P波终末电势值(P terminal force in lead V1,PtfV_(1))和肺功能评分对老年非小细胞肺癌(non-small cell lung cancer,NSCLC)患者术后呼吸衰竭的预测价值。[方法]选取湖南省肿瘤医院2018年9月至2020年12月收...[目的]研究术前心电图V1导联P波终末电势值(P terminal force in lead V1,PtfV_(1))和肺功能评分对老年非小细胞肺癌(non-small cell lung cancer,NSCLC)患者术后呼吸衰竭的预测价值。[方法]选取湖南省肿瘤医院2018年9月至2020年12月收治的116例行手术治疗的老年NSCLC患者为研究对象,术前3 d检测PtfV_(1)水平和肺功能评分。根据术后7 d内是否发生呼吸衰竭分为呼吸衰竭组(24例)和非呼吸衰竭组(92例),比较两组患者PtfV_(1)水平、肺功能评分及其他可能影响因素。采用Logistic回归分析影响老年NSCLC患者术后呼吸衰竭的相关因素。绘制受试者工作特征(receiver operating characteristic curve,ROC)曲线,分析PtfV_(1)水平、肺功能评分对老年NSCLC患者术后呼吸衰竭的预测价值。[结果]Logistic回归分析显示病理分期、术前化疗、PtfV_(1)和肺功能评分均是影响老年NSCLC癌患者术后发生呼吸衰竭的相关因素(P<0.05)。ROC曲线分析显示,PtfV_(1)联合肺功能评分预测老年NSCLC患者术后发生呼吸衰竭的灵敏度、准确率、曲线下面积分别为91.26%、85.97%和0.814,均高于PtfV_(1)(70.31%、68.34%、0.718)、肺功能评分(84.24%、72.64%、0.739)单独预测;但特异度(60.32%)低于PtfV_(1)(85.69%)、肺功能评分(68.39%)单独预测。[结论]PtfV_(1)和肺功能评分是老年NSCLC患者术后发生呼吸衰竭独立危险因素,两者联合检测对老年NSCLC患者术后发生呼吸衰竭具有较高预测价值。展开更多
The Yangbi M_(S)6.4 earthquake occurred on May 21,2021 in western Yunnan,China,where moderate earthquakes strike frequently.It exhibited a typical“foreshock-mainshock-aftershock”sequence and did not occur on a pre-e...The Yangbi M_(S)6.4 earthquake occurred on May 21,2021 in western Yunnan,China,where moderate earthquakes strike frequently.It exhibited a typical“foreshock-mainshock-aftershock”sequence and did not occur on a pre-existing active fault.The seismogenic environment and mechanism of this earthquake have aroused considerable research attention.In this study,we obtain the three-dimensional v_(P),v_(S)and v_(P)/v_(S)images using the v_(P)/v_(S)consistency-constrained double-difference tomography method,which improves the accuracy of v_(P)/v_(S)models.We focus on characteristics of v_(P)/v_(S)images in areas with a lateral resolution of 0.1°,and reveal the seismogenic environment of the Yangbi M_(S)6.4 earthquake.The conclusions are as follows:(1)Low velocity and high-v_(P)/v_(S)anomalies are revealed at different depths around the northern segment of the Red River fault.v_(S)and v_(P)/v_(S)images along the Weixi-Qiaohou-Weishan fault and the buried faults on its west show obviously segmented feature.(2)The source region of the Yangbi M_(S)6.4 earthquake is located in a low-v_(P)/v_(S)zone implying high medium strength.High-v_(P)/v_(S)anomalies in its NW direction indicate cracks development and the existence of fluids or partial melts,which are unfavorable for stress accumulation and triggering large earthquakes.Such conditions have also prevented the earthquake sequence from extending northwestward.(3)With the southeastward extrusion of materials from the Tibetan Plateau,fluid migration was blocked by the low-v_(P)/v_(S)body in the source region.The high-v_(P)/v_(S)anomaly beneath the source region may implies that the fluids or partial melts in the middle and lower crust gradually weakened medium strength at the bottom of the seismogenic layer,and preparing the largest foreshock in the transition zone of high to low v_(P)/v_(S).Meanwhile,tectonic stress incessantly accumulated in the brittle upper crust,eventually led to the M_(S)6.4 earthquake occurrence.展开更多
目的分析心电图P波特征指标、心房颤动血栓危险度评分(congestive heart failure hypertension age diabete mellitus stroke-vascular disease age sex category,CHA_(2)DS_(2)-VASc)联合血清糖链抗原125(carbohydrate antigen 125,CA1...目的分析心电图P波特征指标、心房颤动血栓危险度评分(congestive heart failure hypertension age diabete mellitus stroke-vascular disease age sex category,CHA_(2)DS_(2)-VASc)联合血清糖链抗原125(carbohydrate antigen 125,CA125)指标对住院心力衰竭患者新发心房颤动的预测价值。方法选取2022年1月至2023年8月在南京市浦口人民医院治疗的235例心力衰竭患者为研究对象,根据患者心房颤动的发生情况将其分为新发心房颤动组和非新发心房颤动组,收集患者的临床资料,对比新发心房颤动组和非新发心房颤动组患者的心电图P波特征指标,包括最小P波时限(minimum P-wave duration,P_(min))、最大P波时限(maximum P-wave duration,P_(max))、V_(1)导联P波终末电势(P terminal force in lead V_(1),PTFV_(1))、CHA_(2)DS_(2)-VASc评分、CA125等指标的差异,应用Pearson相关性分析P_(min),P_(max),PTFV_(1),CHA_(2)DS_(2)-VASc评分,CA125与心力衰竭患者新发心房颤动的相关性,最后通过受试者工作特征(receiver operating characteristic,ROC)及曲线下面积(area under curve,AUC)评价P_(min),P_(max),PTFV_(1),CHA_(2)DS_(2)-VASc评分,CA125对心力衰竭患者新发心房颤动的诊断价值。结果新发心房颤动组患者心电图P波特征指标P_(min)低于非新发心房颤动组患者,而P_(max),PTFV_(1)和CHA_(2)DS_(2)-VASc评分及CA125高于非新发心房颤动组患者[(68.05±9.34)ms/(75.36±10.61)ms、(163.76±14.35)ms/(148.90±12.47)ms、(0.065±0.015)mm/s/(0.059±0.008)mm/s、(3.91±1.52)分/(3.05±1.15)分、(84.62±18.54)U/mL/(71.28±16.34)U/mL];logistic回归分析显示,P_(max),PTFV_(1),CHA_(2)DS_(2)-VASc评分,CA125水平升高和P_(min)降低是新发心房颤动的危险因素(OR=1.059,95%CI:1.021~1.098,P<0.05;OR=1.963,95%CI:1.185~3.250,P<0.05;OR=1.474,95%CI:1.064~2.042,P<0.05;OR=1.049,95%CI:1.016~1.082,P<0.05;OR=-0.051,95%CI:0.913~0.989,P<0.05)。P_(max),PTFV_(1),CHA_(2)DS_(2)-VASc评分及CA125与心力衰竭患者新发心房颤动呈正相关(r=0.374,P<0.001;r=0.334,P<0.001;r=0.302,P<0.001;r=0.288,P<0.001),而P_(min)与心力衰竭患者新发心房颤动呈负相关(r=-0.278,P<0.001)。ROC曲线结果显示,P_(min),P_(max),PTFV_(1),CHA_(2)DS_(2)-VASc评分,CA125联合检测预测心力衰竭患者新发心房颤动的AUC值高于各指标单独检测(0.916/0.687、0.771、0.707、0.671、0.729,P<0.05)。结论心力衰竭住院患者P_(min),P_(max),PTFV_(1),CHA_(2)DS_(2)-VASc评分及CA125水平与心力衰竭住院患者新发心房颤动的发生有较高相关性,且心电图P波特征指标、CHA_(2)DS_(2)-VASc评分和血清CA125联合检测心力衰竭住院患者新发心房颤动的诊断效能优于各指标单独检测。展开更多
基金the National Natural Science Foundation of China(41904116,41874156,42074167 and 42204135)the Natural Science Foundation of Hunan Province(2020JJ5168)the China Postdoctoral Science Foundation(2021M703629)for their funding of this research.
文摘As an important indicator parameter of fluid identification,fluid factor has always been a concern for scholars.However,when predicting Russell fluid factor or effective pore-fluid bulk modulus,it is necessary to introduce a new rock skeleton parameter which is the dry-rock VP/VS ratio squared(DVRS).In the process of fluid factor calculation or inversion,the existing methods take this parameter as a static constant,which has been estimated in advance,and then apply it to the fluid factor calculation and inversion.The fluid identification analysis based on a portion of the Marmousi 2 model and numerical forward modeling test show that,taking the DVRS as a static constant will limit the identification ability of fluid factor and reduce the inversion accuracy.To solve the above problems,we proposed a new method to regard the DVRS as a dynamic variable varying with depth and lithology for the first time,then apply it to fluid factor calculation and inversion.Firstly,the exact Zoeppritz equations are rewritten into a new form containing the fluid factor and DVRS of upper and lower layers.Next,the new equations are applied to the four parameters simultaneous inversion based on the generalized nonlinear inversion(GNI)method.The testing results on a portion of the Marmousi 2 model and field data show that dynamic DVRS can significantly improve the fluid factor identification ability,effectively suppress illusion.Both synthetic and filed data tests also demonstrate that the GNI method based on Bayesian deterministic inversion(BDI)theory can successfully solve the above four parameter simultaneous inversion problem,and taking the dynamic DVRS as a target inversion parameter can effectively improve the inversion accuracy of fluid factor.All these results completely verified the feasibility and effectiveness of the proposed method.
基金supported by the National Natural Science Foundation of China(42304056)the Natural Science Foundation of Hebei Province(D2023305007)+1 种基金supported by the Basic Research Project(GP2020-017,GP2020027)of the Korea Institute of Geoscience and Mineral Resources(KIGAM)funded by the Ministry of Science and ICT of Korea。
文摘Geothermal resources are a promising approach to clean renewable energy;90%of them are deep reservoirs of hot dry rock that require hydraulic fracturing to create a network of connections among wells to enable efficient heat exchange,known as an Enhanced Geothermal System(EGS).The Pohang EGS project in south Korea led to a devasting Mw5.5 earthquake,triggered by the reservoir's EGS stimulation,the largest earthquake known to have been induced by EGS development.Detailed investigations have been conducted to understand the cause of the Pohang earthquake;the conclusion has been that overpressurized injected fluids migrated into an unknown fault triggering this large earthquake.Detailed velocity images for the source zone of the 2017 Pohang earthquake,which could be helpful for further understanding its inducing mechanism,are unavailable.However,we have assembled detailed aftershock data recorded by 41 local stations installed within about three months after the Mw5.5 Pohang earthquake,and have then applied the V_(p)/V_(s)model's consistency-constrained double-difference seismic tomography method to determine the high-resolution three-dimensional Vp(compressional wave velocity),Vs(shear wave velocity),and V_(p)/V_(s)models of the source region that we report here,as well as earthquake locations within the source region.The velocity images reveal that the deep source area of the 2017 Pohang earthquake is dominated by low Vp,high Vs,and low V_(p)/V_(s)anomalies,a pattern that can be caused by overpressurized vapors due to high temperatures at these depths.Based on aftershock locations and velocity features,our studies support the conclusion that the 2017Pohang earthquake was triggered by injected EGS fluids that migrated into a blind fault.
基金the National Natural Science Foundation of China(Nos.U1939204,and 41774056).
文摘The Hi-CLIMB seismic array is located in the central-western Tibetan Plateau.The H-κ-c method(Li JT et al.,2019)was applied to receiver function data on the HiCLIMB,which corrects the back-azimuthal variations in the arrival times of Ps and crustal multiples caused by crustal anisotropy and dipping interfaces before performing H-κstacking.Compared to the traditional H-κmethod,the H-κstacking results after harmonic corrections showed considerable improvements,including greatly reduced errors,significantly less scattered H(crustal thickness)andκ(crustal v_(P)/v_(S)ratio)values,and clearer patterns of H andκin different Tibetan blocks.This demonstrates that the H-κ-c method works well even for regions with complex crustal structures,such as the Tibetan Plateau,when there are helpful references from nearby stations or other constraints.The variation in crustal thickness agrees with previous studies but tends to be relatively shallower beneath most of the plateau.Two regions with particularly high crustal v_(P)/v_(S)were observed,namely,one in the northern Himalaya block and beneath the YarlungZangbo suture,and the other in the Qiangtang block.Their correlation with mid-crust low S velocities from previous studies suggests the possible presence of fluid or partial melt in the two regions,which may have implications for the crustal flow model.In contrast,the Lhasa block had relatively lower crustal v_(P)/v_(S)and relatively higher crustal S velocity within the plateau,which is interpreted to be mechanically stronger than the Himalaya and Qiangtang blocks,and without mid-crust partial melt.
基金supported by the National Science Foundation of China(No.U1839210)。
文摘The North China Craton(NCC)is one of the oldest cratons on earth.Several important tectonic transformations of MesozoicCenozoic tectonic regime led to the destruction of the North China craton.The knowledge of crustal structure can provide important constraints for the formation and evolution of cratons.New maps of sediment thickness,crustal thickness(H)and v_(P)/v_(S)(κ)in the central and western NCC were obtained using sequential H-κstacking.P-wave receiver functions are calculated using teleseismic waveform data recorded by 405 stations from Chin Array project.Benefiting from the densely distribution of temporary seismic stations,our results reveal details of the crustal structure in the study area.The thickness of sedimentary layer in North China ranges from 0–6.4 km,and the thickest sedimentary layer is in Ordos block and its surroundings(about 2.8–6 km);The thickness of sedimentary layer in the Mongolia fold belt and Yinshan orogenic belt is relatively thin(less than 1 km).The crustal thickness of the study area varies between 27–48 km,of which the crust of the North China Plain is about 30–33 km,the central NCC is about 33–40 km,and the Ordos block is 40–48 km thick.The average v_(P)/v_(S)ratios in the study area is mostly between 1.66 and 1.90,and that in the Yanshan-Taihang mountain fold belt is between 1.70 and 1.85,and that in the Ordos block is between 1.65 and 1.90,with an average value of 1.77,indicating the absence of a thick basaltic lower crust.The obvious negative correlation between crustal thickness and average v_(P)/v_(S)ratio within Ordos and Central Asia orogenic belt may be related to magmatic underplating during the crustal formation.There is no significant correlation between the crustal thickness and the v_(P)/v_(S)ratio in the Lüliang-Taihang mountain fold belt,which may be related to the multiple geological processes such as underplating and crustal extension and thinning in this area.The lack of correlation between crust thickness and topography in the central orogenic belt and the North China Basin indicates the topography of these areas are controlled not only by crustal isostatic adjustment but also by the lithospheric mantle processes.
文摘[目的]研究术前心电图V1导联P波终末电势值(P terminal force in lead V1,PtfV_(1))和肺功能评分对老年非小细胞肺癌(non-small cell lung cancer,NSCLC)患者术后呼吸衰竭的预测价值。[方法]选取湖南省肿瘤医院2018年9月至2020年12月收治的116例行手术治疗的老年NSCLC患者为研究对象,术前3 d检测PtfV_(1)水平和肺功能评分。根据术后7 d内是否发生呼吸衰竭分为呼吸衰竭组(24例)和非呼吸衰竭组(92例),比较两组患者PtfV_(1)水平、肺功能评分及其他可能影响因素。采用Logistic回归分析影响老年NSCLC患者术后呼吸衰竭的相关因素。绘制受试者工作特征(receiver operating characteristic curve,ROC)曲线,分析PtfV_(1)水平、肺功能评分对老年NSCLC患者术后呼吸衰竭的预测价值。[结果]Logistic回归分析显示病理分期、术前化疗、PtfV_(1)和肺功能评分均是影响老年NSCLC癌患者术后发生呼吸衰竭的相关因素(P<0.05)。ROC曲线分析显示,PtfV_(1)联合肺功能评分预测老年NSCLC患者术后发生呼吸衰竭的灵敏度、准确率、曲线下面积分别为91.26%、85.97%和0.814,均高于PtfV_(1)(70.31%、68.34%、0.718)、肺功能评分(84.24%、72.64%、0.739)单独预测;但特异度(60.32%)低于PtfV_(1)(85.69%)、肺功能评分(68.39%)单独预测。[结论]PtfV_(1)和肺功能评分是老年NSCLC患者术后发生呼吸衰竭独立危险因素,两者联合检测对老年NSCLC患者术后发生呼吸衰竭具有较高预测价值。
基金This work was jointly supported by the National Key R&D Program of China(No.2021YFC3000700)the National Natural Science Foundation of China(No.42174066).
文摘The Yangbi M_(S)6.4 earthquake occurred on May 21,2021 in western Yunnan,China,where moderate earthquakes strike frequently.It exhibited a typical“foreshock-mainshock-aftershock”sequence and did not occur on a pre-existing active fault.The seismogenic environment and mechanism of this earthquake have aroused considerable research attention.In this study,we obtain the three-dimensional v_(P),v_(S)and v_(P)/v_(S)images using the v_(P)/v_(S)consistency-constrained double-difference tomography method,which improves the accuracy of v_(P)/v_(S)models.We focus on characteristics of v_(P)/v_(S)images in areas with a lateral resolution of 0.1°,and reveal the seismogenic environment of the Yangbi M_(S)6.4 earthquake.The conclusions are as follows:(1)Low velocity and high-v_(P)/v_(S)anomalies are revealed at different depths around the northern segment of the Red River fault.v_(S)and v_(P)/v_(S)images along the Weixi-Qiaohou-Weishan fault and the buried faults on its west show obviously segmented feature.(2)The source region of the Yangbi M_(S)6.4 earthquake is located in a low-v_(P)/v_(S)zone implying high medium strength.High-v_(P)/v_(S)anomalies in its NW direction indicate cracks development and the existence of fluids or partial melts,which are unfavorable for stress accumulation and triggering large earthquakes.Such conditions have also prevented the earthquake sequence from extending northwestward.(3)With the southeastward extrusion of materials from the Tibetan Plateau,fluid migration was blocked by the low-v_(P)/v_(S)body in the source region.The high-v_(P)/v_(S)anomaly beneath the source region may implies that the fluids or partial melts in the middle and lower crust gradually weakened medium strength at the bottom of the seismogenic layer,and preparing the largest foreshock in the transition zone of high to low v_(P)/v_(S).Meanwhile,tectonic stress incessantly accumulated in the brittle upper crust,eventually led to the M_(S)6.4 earthquake occurrence.
文摘目的分析心电图P波特征指标、心房颤动血栓危险度评分(congestive heart failure hypertension age diabete mellitus stroke-vascular disease age sex category,CHA_(2)DS_(2)-VASc)联合血清糖链抗原125(carbohydrate antigen 125,CA125)指标对住院心力衰竭患者新发心房颤动的预测价值。方法选取2022年1月至2023年8月在南京市浦口人民医院治疗的235例心力衰竭患者为研究对象,根据患者心房颤动的发生情况将其分为新发心房颤动组和非新发心房颤动组,收集患者的临床资料,对比新发心房颤动组和非新发心房颤动组患者的心电图P波特征指标,包括最小P波时限(minimum P-wave duration,P_(min))、最大P波时限(maximum P-wave duration,P_(max))、V_(1)导联P波终末电势(P terminal force in lead V_(1),PTFV_(1))、CHA_(2)DS_(2)-VASc评分、CA125等指标的差异,应用Pearson相关性分析P_(min),P_(max),PTFV_(1),CHA_(2)DS_(2)-VASc评分,CA125与心力衰竭患者新发心房颤动的相关性,最后通过受试者工作特征(receiver operating characteristic,ROC)及曲线下面积(area under curve,AUC)评价P_(min),P_(max),PTFV_(1),CHA_(2)DS_(2)-VASc评分,CA125对心力衰竭患者新发心房颤动的诊断价值。结果新发心房颤动组患者心电图P波特征指标P_(min)低于非新发心房颤动组患者,而P_(max),PTFV_(1)和CHA_(2)DS_(2)-VASc评分及CA125高于非新发心房颤动组患者[(68.05±9.34)ms/(75.36±10.61)ms、(163.76±14.35)ms/(148.90±12.47)ms、(0.065±0.015)mm/s/(0.059±0.008)mm/s、(3.91±1.52)分/(3.05±1.15)分、(84.62±18.54)U/mL/(71.28±16.34)U/mL];logistic回归分析显示,P_(max),PTFV_(1),CHA_(2)DS_(2)-VASc评分,CA125水平升高和P_(min)降低是新发心房颤动的危险因素(OR=1.059,95%CI:1.021~1.098,P<0.05;OR=1.963,95%CI:1.185~3.250,P<0.05;OR=1.474,95%CI:1.064~2.042,P<0.05;OR=1.049,95%CI:1.016~1.082,P<0.05;OR=-0.051,95%CI:0.913~0.989,P<0.05)。P_(max),PTFV_(1),CHA_(2)DS_(2)-VASc评分及CA125与心力衰竭患者新发心房颤动呈正相关(r=0.374,P<0.001;r=0.334,P<0.001;r=0.302,P<0.001;r=0.288,P<0.001),而P_(min)与心力衰竭患者新发心房颤动呈负相关(r=-0.278,P<0.001)。ROC曲线结果显示,P_(min),P_(max),PTFV_(1),CHA_(2)DS_(2)-VASc评分,CA125联合检测预测心力衰竭患者新发心房颤动的AUC值高于各指标单独检测(0.916/0.687、0.771、0.707、0.671、0.729,P<0.05)。结论心力衰竭住院患者P_(min),P_(max),PTFV_(1),CHA_(2)DS_(2)-VASc评分及CA125水平与心力衰竭住院患者新发心房颤动的发生有较高相关性,且心电图P波特征指标、CHA_(2)DS_(2)-VASc评分和血清CA125联合检测心力衰竭住院患者新发心房颤动的诊断效能优于各指标单独检测。
