This study investigates the influence of the elastic modulus(E)of the composite strata on the trough width coefficient(i).It is hypothesized that,in composite strata,the relationship between the trough width coefficie...This study investigates the influence of the elastic modulus(E)of the composite strata on the trough width coefficient(i).It is hypothesized that,in composite strata,the relationship between the trough width coefficient(i)and the stratum thickness(H)follows a piecewise linear trend.Specifically,within strata of identical elastic modulus(E),i exhibits a linear correlation with H,while variations in E affect the slope of this correlation.Building upon the non-iterative analytical method(NIAM)for evaluating tunnel excavation responses in composite strata,this study proposes two novel approaches:the crucial point method(CPM)and the standard curve method(SCM).These methods incorporate the elastic modulus into the estimation of i.The values of i obtained via NIAM and refined through CPM and SCM are validated against field data using the parameter K.The results are consistent with existing research findings,thereby confirming the reliability of the proposed methodology.Furthermore,the study investigates the relationship between tunnel depth(h0)and tunnel radius(R),and explores the interactions among the layer number of stratum(n),elastic modulus(E),and layer thickness(H).A reduction coefficient(η)is introduced to improve the model's accuracy.The proposed approach is applied to nine tunnel engineering cases,and comparisons with measured data demonstrate its accuracy and practical applicability.展开更多
Statistical characteristics and the classification of the topside ionospheric mid-latitude trough are systemically analyzed,using observations from the Defense Meteorological Satellite Program F18(DMSP-F18)satellite.T...Statistical characteristics and the classification of the topside ionospheric mid-latitude trough are systemically analyzed,using observations from the Defense Meteorological Satellite Program F18(DMSP-F18)satellite.The data was obtained at an altitude of around 860 km in near polar orbit,throughout 2013.Our study identified the auroral boundary based on the in-situ electron density and electron spectrum,allowing us to precisely determine the location of the mid-latitude trough.This differs from most previous works,which only use Total Electron Content(TEC)or in-situ electron density.In our study,the troughs exhibited a higher occurrence rate in local winter than in summer,and extended to lower latitudes with increasing geomagnetic activity.It was found that the ionospheric mid-latitude trough,which is associated with temperature changes or enhanced ion drift,exhibited distinct characteristics.Specifically,the ionospheric mid-latitude troughs related to electron temperature(Te)peak were located more equatorward of auroral oval boundary in winter than in summer.The ionospheric mid-latitude troughs related to Te-maximum were less frequently observed at 60−70°S magnetic latitude and 90−240°E longitude.Furthermore,the troughs related to ion temperature(Ti)maximums were observed at relatively higher latitudes,occurring more frequently in winter.In addition,the troughs related to ion velocity(Vi)maximums could be observed in all seasons.The troughs with the maximum-Ti and maximum-Vi were located closer to the equatorward boundary of the auroral oval at the nightside,and in both hemispheres.This implies that enhanced ion drift velocity contributes to increased collisional frictional heating and enhanced ion temperatures,resulting in a density depletion within the trough region.展开更多
BACKGROUND Ulcerative colitis(UC)is a chronic inflammatory condition requiring continuous treatment and monitoring.There is limited pharmacokinetic data on vedolizumab during maintenance therapy and the effect of thio...BACKGROUND Ulcerative colitis(UC)is a chronic inflammatory condition requiring continuous treatment and monitoring.There is limited pharmacokinetic data on vedolizumab during maintenance therapy and the effect of thiopurines on vedolizumab trough concentrations is unknown.AIM To investigate the exposure-response relationship of vedolizumab and the impact of thiopurine withdrawal in UC patients who have achieved sustained clinical and endoscopic remission during maintenance therapy.METHODS This is a post-hoc analysis of prospective randomized clinical trial(VIEWS)involving UC patients across 8 centers in Australia from 2018 to 2022.Patients in clinical and endoscopic remission were randomized to continue or withdraw thiopurine while receiving vedolizumab.We evaluated vedolizumab serum trough concentrations,presence of anti-vedolizumab antibodies,and clinical outcomes over 48 weeks to assess exposure-response asso-ciation and impact of thiopurine withdrawal.RESULTS There were 62 UC participants with mean age of 43.4 years and 42%were females.All participants received vedolizumab as maintenance therapy with 67.7%withdrew thiopurine.Vedolizumab serum trough concentrations remained stable over 48 weeks regardless of thiopurine use,with no anti-vedolizumab antibodies detected.Pa-tients with clinical remission had higher trough concentrations at week 48.In quartile analysis,a threshold of>11.3μg/mL was associated with sustained clinical remission,showing a sensitivity of 82.4%,specificity of 60.0%,and an area of receiver operating characteristic of 0.71(95%CI:0.49-0.93).Patients discontinuing thiopurine required higher vedolizumab concentrations for achieving remission.CONCLUSION A positive exposure-response relationship between vedolizumab trough concentrations and UC outcomes suggests that monitoring drug levels may be beneficial.While thiopurine did not influence vedolizumab levels,its with-drawal may necessitate higher vedolizumab trough concentrations to maintain remission.展开更多
To investigate groundwater flow and solute transport characteristics of the karst trough zone in China,tracer experiments were conducted at two adjacent typical karst groundwater flow systems(Yuquandong(YQD)and Migong...To investigate groundwater flow and solute transport characteristics of the karst trough zone in China,tracer experiments were conducted at two adjacent typical karst groundwater flow systems(Yuquandong(YQD)and Migongquan(MGQ))in Sixi valley,western Hubei,China.Highresolution continuous monitoring was utilized to obtain breakthrough curves(BTCs),which were then analyzed using the multi-dispersion model(MDM)and the two-region nonequilibrium model(2RNE)with basic parameters calculated by CXTFIT and QTRACER2.Results showed that:(1)YQD flow system had a complex infiltration matrix with overland flow,conduit flow and fracture flow,while the MGQ flow system was dominated by conduit flow with fast flow transport velocity,but also small amount of fracture flow there;(2)They were well fitted based on the MDM(R^2=0.928)and 2RNE(R^2=0.947)models,indicating that they had strong adaptability in the karst trough zone;(3)conceptual models for YQD and MGQ groundwater systems were generalized.In YQD system,the solute was transported via overland flow during intense rainfall,while some infiltrated down into fissures and conduits.In MGQ system,most were directly transported to spring outlet in the fissureconduit network.展开更多
Three extreme cold events occurred in eastern Asia in January 2016,January 2021,and December 2023.As important factors in atmospheric circulation anomalies,the Blocking High and East Asian Trough(BH-ET)structure playe...Three extreme cold events occurred in eastern Asia in January 2016,January 2021,and December 2023.As important factors in atmospheric circulation anomalies,the Blocking High and East Asian Trough(BH-ET)structure played key roles during these three extreme cold wave events.Among these two dynamic patterns,the BH affected the development of the cold waves in two different ways:(1)before the cold waves in 2016 and 2023,the BH pushed the cold air southward,resulting in a slow and gradual cooling,with a cooling rate(CR)in eastern Asia of 1.34℃d^(-1)and 1.2℃d^(-1),respectively,and(2)in January 2021,the sudden collapse of BH caused the cold air to rapidly attack mid-latitude regions,with a CR of 1.87℃d^(-1).In terms of the spatial CR,the temperature drop in 2021 occurred 38.8%and 55%faster than those in 2016 and 2023,respectively.At the same time,the ET influences the wind direction of cold waves by modulating the pressure gradient.Before the cold waves occurred,the meridional wind field near the ET showed negative values,forming northwesterly or northeasterly winds,which continued to affect the southern part of East Asia.The meridional wind in January 2021 was stronger than those in 2016 and 2023,which is thought to be the reason for the strength of the 2021 cold wave.Finally,results from the temperature Empirical Orthogonal Function(EOF)analysis from 1980-2023 verify an obvious BH-ET structure in the three cold wave events,which suggests that this particular climatological state provides a climatic background for the occurrence of cold waves.展开更多
The Cambrian Qiongzhusi Formation in the Sichuan Basin harbors significant potential for shale gas harvesting.However,systematic disparities in mineral composition and reservoir architecture have been observed between...The Cambrian Qiongzhusi Formation in the Sichuan Basin harbors significant potential for shale gas harvesting.However,systematic disparities in mineral composition and reservoir architecture have been observed between intra-and extra-trough reservoirs within the Deyang-Anyue Rift Trough.These variations were primarily determined by divergences in the sedimentary environments developed during the evolution of the rift trough,which were a main factor in fostering the heterogeneous distribution of shale gas enrichment found today.However,the genetic mechanisms that govern reservoir heterogeneity across distinct structural domains(intra-trough,trough margin,and extra-trough)remain poorly understood,particularly regarding the coupling relationships between depositional environments,reservoir characteristics,and gas-bearing properties.This study adopts a multidisciplinary approach to investigating this issue that integrates core analysis,well-log interpretations,and geochemical data.Through systematic comparisons conducted using X-ray diffraction mineralogy,organic carbon quantification,and spontaneous imbibition experiments,we characterize the mineral assemblages,organic geochemical signatures,and pore structures found across the three structural domains of the Deyang-Anyue Rift Trough.The key findings are as follows:(1)The depositional environment is the main influence on reservoir distribution and organic matter enrichment,with intra-trough shales exhibiting a higher abundance of organic matter than their trough-margin and extra-trough counterparts.(2)Enhanced brittleness in intra-trough zones correlates with the predominance of biogenic silica therein.(3)Synergistic organic-inorganic interactions govern pore system development.(4)Gas-bearing capacity is jointly determined by effective porosity and organic matter content.These findings establish the rift trough as a preferential exploration target,providing critical geological guidance for optimizing shale gas exploration strategies in the Cambrian Qiongzhusi Formation.展开更多
BACKGROUND Plasma concentration monitoring is crucial for optimizing vancomycin use,particularly in patients in the intensive care unit(ICU).However,the reference interval for vancomycin plasma concentration remains u...BACKGROUND Plasma concentration monitoring is crucial for optimizing vancomycin use,particularly in patients in the intensive care unit(ICU).However,the reference interval for vancomycin plasma concentration remains undetermined.AIM To evaluate the correlations of area under the curve(AUC_(0-24))and trough concentration(C_(min))with efficacy and nephrotoxicity in patients in the ICU.METHODS A total of 103 patients treated with vancomycin for methicillin-resistant Staphylococcus aureus infections were analyzed in this study.The associations of clinicodemographic characteristics(including sex,age,weight,infection sites,main etiologies of ICU cases,comorbidities,acute physiological chronic health evaluation II score,and mechanical ventilation)and pharmacokinetics(daily dose,C_(min),AUC_(0-24),and AUC_(0-24)/minimum inhibitory concentration)with efficacy and nephrotoxicity of vancomycin were evaluated with univariate and multivariate logistic regression analyses.AUC_(0-24)was calculated using VCM-TDM software based on vancomycin population pharmacokinetics and Bayesian feedback method.RESULTS Cmin over 9.4μg/mL and AUC_(0-24)exceeding 359.6μg×hour/mL indicated good efficacy against infection.Cmin below 14.0μg/mL predicted no significant nephrotoxicity.CONCLUSION In this study,the effective and safe concentration interval for vancomycin in patients in the ICU was Cmin 9.4-14.0μg/mL.Close attention should be paid to adverse effects and renal function during vancomycin treatment.展开更多
Taking the natural gas reservoirs of the Sinian Dengying Formation on the east and west sides(Gaoshiti-Moxi area and north slope of central Sichuan paleo-uplift on the east;Weiyuan and Well Datan-1 block on the west)o...Taking the natural gas reservoirs of the Sinian Dengying Formation on the east and west sides(Gaoshiti-Moxi area and north slope of central Sichuan paleo-uplift on the east;Weiyuan and Well Datan-1 block on the west)of the Deyang-Anyue rift trough in the Sichuan Basin,China,as the research object,the geochemical parameters(component,isotopic composition)of natural gas from the Dengying Formation in different areas are compared,and then the differences in geochemical characteristics of Dengying natural gas on the east and west sides of the Deyang-Anyue rift trough and their genesis are clarified.First,the Dengying gas reservoirs on both sides of the rift trough are predominantly composed of oil-cracking gas with high maturity,which is typical dry gas.Second,severely modified by thermochemical sulfate reduction(TSR)reaction,the Dengying gas reservoirs on the east side exhibit high H2S and CO_(2) contents,with an elevated δ^(13)C_(2) value(average value higher than-29‰).The Dengying gas reservoirs in the Weiyuan area are less affected by TSR modification,though the δ^(13)C_(1) values are slightly greater than that of the reservoirs on the east side with partial reversal of carbon isotope composition,likely due to the water-soluble gas precipitation and accumulation mechanism.The Dengying gas reservoir of Well Datan-1 shows no influence from TSR.Third,the Dengying gas reservoirs reflect high helium contents(significantly higher than that on the east side)in the Weiyuan and Datan-1 areas on the west side,which is supposed to attribute to the widespread granites in basement and efficient vertical transport along faults.Fourth,controlled by the paleo-salinity of water medium in the depositional period of the source rock,the δ^(2)HCH_(4) values of the Dengying gas reservoirs on the west side are slightly lighter than those on the east side.Fifth,the Dengying natural gas in the Datan-1 area is contributed by the source rocks of the Sinian Doushantuo Formation and the third member of the Dengying Formation,in addition to the Cambrian Qiongzhusi Formation.展开更多
The coal resources of Nigeria occur mainly within the Benue Trough which includes the Anambra Basin. In the Lower Benue Trough/Anambra Basin, sub-bituminous coals occur within the Maastrichtian Mamu Formation in Enugu...The coal resources of Nigeria occur mainly within the Benue Trough which includes the Anambra Basin. In the Lower Benue Trough/Anambra Basin, sub-bituminous coals occur within the Maastrichtian Mamu Formation in Enugu （Enugu State）, Owukpa （Benue State）, Okaba （Kogi State） and Ogboyaga （Kogi State）. High-volatile bituminous coals occur within the Turonian-Coniacian Awgu Formation in the Middle Benue Trough around Obi/Lafia （Nasarawa State） with outcrop exposures at Jangwa-Shankodi. Organic petrographic results show that huminites dominate the maceral composition of the Anambra Basin coals and have vitrinite reflectance values that range from 0.40% to 0.63 Ro%. In the coals from the Middle Benue Trough, vitrinite macerals predominate the petrographic composition and Ro values range from 0.81% to 1.25%. Based on the petrographic composition and rank evaluation, the sub-bituminous coals in Enugu, Owukpa, Okaba and Ogboyaga （Anambra Basin） are optimum for combustion and electric power generation and sub-optimum for liquefaction, while the high-volatile bituminous coals in the Obi/Lafia area （Middle Benue Trough）, apart from being optimum for liquefaction, are the most suitable as raw material for coke making （carbonization） in steel manufacture and as exploration targets for coal-bed methane gas and liquid hydrocarbons.展开更多
Based on the data of seismic reflection, seismic refraction and magnetism collected in the research area and geology obtained from adjacent areas, this paper deals with the issue of basement constitution of the southe...Based on the data of seismic reflection, seismic refraction and magnetism collected in the research area and geology obtained from adjacent areas, this paper deals with the issue of basement constitution of the southern part of the Okinawa Trough. In the shelf basin of the East China Sea, Taiwan folded belt and Ryukyu Islands folded belt which surround the trough, outcrop Later Paleozoic, Mesozoic and Eogene strata. In the southern trough, multichannel seismic reflection data indicate that the overlying strata are composed of Neogene and Quaternary deposits, and the acoustic basement consists of Eogent and even older strata. Seismic refraction profiles show that there are Eogene and Mesozoic velocity layers with longitudinal velocities of 4.7 - 5.3 km/s and 6.3 km/s respectively beneath the Quaternary-Miocene Layers. Qualitative analysis and forward and reversed calculation of magnetic data show that the magnetic basement is mainly formed by metamorphic rocks, the Yanshanian neutral-acid magmatic rocks and the Himalayan neutral-basic magmatic rocks being the next components, and the magnetic basement is mostly corresponding to the acoustic basement. Comprehensive analyses demonstrate that the basement of the southern Okinawa Trough is mainly formed by Eogene system and Mesozoic and Upper Paleozoic groups metamorphosed in varying degrees, and the basic magmatic rocks of Himalayan epoch have been formed in some parts of the basin.展开更多
基金support from the National Natural Science Foundation of China(Grant No.52278387).
文摘This study investigates the influence of the elastic modulus(E)of the composite strata on the trough width coefficient(i).It is hypothesized that,in composite strata,the relationship between the trough width coefficient(i)and the stratum thickness(H)follows a piecewise linear trend.Specifically,within strata of identical elastic modulus(E),i exhibits a linear correlation with H,while variations in E affect the slope of this correlation.Building upon the non-iterative analytical method(NIAM)for evaluating tunnel excavation responses in composite strata,this study proposes two novel approaches:the crucial point method(CPM)and the standard curve method(SCM).These methods incorporate the elastic modulus into the estimation of i.The values of i obtained via NIAM and refined through CPM and SCM are validated against field data using the parameter K.The results are consistent with existing research findings,thereby confirming the reliability of the proposed methodology.Furthermore,the study investigates the relationship between tunnel depth(h0)and tunnel radius(R),and explores the interactions among the layer number of stratum(n),elastic modulus(E),and layer thickness(H).A reduction coefficient(η)is introduced to improve the model's accuracy.The proposed approach is applied to nine tunnel engineering cases,and comparisons with measured data demonstrate its accuracy and practical applicability.
基金supported by the National Key R&D Program of China(2022YFF0504400)the National Natural Science Foundation of China(42188101,42274195,42174193)+2 种基金the International Partnership Program Of Chinese Academy of Sciences(Grant No.183311KYSB20200003)the USTC Research Funds of the Double First-Class Initiative(YD2080002013)the Joint Open Fund of Mengcheng National Geophysical Observatory(MENGO-202408).
文摘Statistical characteristics and the classification of the topside ionospheric mid-latitude trough are systemically analyzed,using observations from the Defense Meteorological Satellite Program F18(DMSP-F18)satellite.The data was obtained at an altitude of around 860 km in near polar orbit,throughout 2013.Our study identified the auroral boundary based on the in-situ electron density and electron spectrum,allowing us to precisely determine the location of the mid-latitude trough.This differs from most previous works,which only use Total Electron Content(TEC)or in-situ electron density.In our study,the troughs exhibited a higher occurrence rate in local winter than in summer,and extended to lower latitudes with increasing geomagnetic activity.It was found that the ionospheric mid-latitude trough,which is associated with temperature changes or enhanced ion drift,exhibited distinct characteristics.Specifically,the ionospheric mid-latitude troughs related to electron temperature(Te)peak were located more equatorward of auroral oval boundary in winter than in summer.The ionospheric mid-latitude troughs related to Te-maximum were less frequently observed at 60−70°S magnetic latitude and 90−240°E longitude.Furthermore,the troughs related to ion temperature(Ti)maximums were observed at relatively higher latitudes,occurring more frequently in winter.In addition,the troughs related to ion velocity(Vi)maximums could be observed in all seasons.The troughs with the maximum-Ti and maximum-Vi were located closer to the equatorward boundary of the auroral oval at the nightside,and in both hemispheres.This implies that enhanced ion drift velocity contributes to increased collisional frictional heating and enhanced ion temperatures,resulting in a density depletion within the trough region.
基金Supported by Takeda Australia,No.IISR-2016-101883.
文摘BACKGROUND Ulcerative colitis(UC)is a chronic inflammatory condition requiring continuous treatment and monitoring.There is limited pharmacokinetic data on vedolizumab during maintenance therapy and the effect of thiopurines on vedolizumab trough concentrations is unknown.AIM To investigate the exposure-response relationship of vedolizumab and the impact of thiopurine withdrawal in UC patients who have achieved sustained clinical and endoscopic remission during maintenance therapy.METHODS This is a post-hoc analysis of prospective randomized clinical trial(VIEWS)involving UC patients across 8 centers in Australia from 2018 to 2022.Patients in clinical and endoscopic remission were randomized to continue or withdraw thiopurine while receiving vedolizumab.We evaluated vedolizumab serum trough concentrations,presence of anti-vedolizumab antibodies,and clinical outcomes over 48 weeks to assess exposure-response asso-ciation and impact of thiopurine withdrawal.RESULTS There were 62 UC participants with mean age of 43.4 years and 42%were females.All participants received vedolizumab as maintenance therapy with 67.7%withdrew thiopurine.Vedolizumab serum trough concentrations remained stable over 48 weeks regardless of thiopurine use,with no anti-vedolizumab antibodies detected.Pa-tients with clinical remission had higher trough concentrations at week 48.In quartile analysis,a threshold of>11.3μg/mL was associated with sustained clinical remission,showing a sensitivity of 82.4%,specificity of 60.0%,and an area of receiver operating characteristic of 0.71(95%CI:0.49-0.93).Patients discontinuing thiopurine required higher vedolizumab concentrations for achieving remission.CONCLUSION A positive exposure-response relationship between vedolizumab trough concentrations and UC outcomes suggests that monitoring drug levels may be beneficial.While thiopurine did not influence vedolizumab levels,its with-drawal may necessitate higher vedolizumab trough concentrations to maintain remission.
基金supported by the National Natural Science Foundation of China(Nos.42007178 and 41907327)the Natural Science Foundation of Hubei(Nos.2020CFB463 and 2019CFB372)+4 种基金China Geological Survey(Nos.DD20160304 and DD20190824)Fundamental Research Funds for the Central Universities(Nos.CUG 190644 and CUGL180817)National Key Research and Development Program(No.2019YFC1805502)Key Laboratory of Karst Dynamics,MNR and GZAR(Institute of Karst Geology,CAGS)Guilin(No.KDL201703)Key Laboratory of Karst Ecosystem and Treatment of Rocky Desertification,MNR and IRCK by UNESCO(No.KDL201903)。
文摘To investigate groundwater flow and solute transport characteristics of the karst trough zone in China,tracer experiments were conducted at two adjacent typical karst groundwater flow systems(Yuquandong(YQD)and Migongquan(MGQ))in Sixi valley,western Hubei,China.Highresolution continuous monitoring was utilized to obtain breakthrough curves(BTCs),which were then analyzed using the multi-dispersion model(MDM)and the two-region nonequilibrium model(2RNE)with basic parameters calculated by CXTFIT and QTRACER2.Results showed that:(1)YQD flow system had a complex infiltration matrix with overland flow,conduit flow and fracture flow,while the MGQ flow system was dominated by conduit flow with fast flow transport velocity,but also small amount of fracture flow there;(2)They were well fitted based on the MDM(R^2=0.928)and 2RNE(R^2=0.947)models,indicating that they had strong adaptability in the karst trough zone;(3)conceptual models for YQD and MGQ groundwater systems were generalized.In YQD system,the solute was transported via overland flow during intense rainfall,while some infiltrated down into fissures and conduits.In MGQ system,most were directly transported to spring outlet in the fissureconduit network.
基金supported by the National Natural Science Foundation of China under Grant No.41821004,the National Key Research and Development Program of China under contract No.2022YFE0140500the National Key R&D Program of China under contract No.2022YFA1004403+2 种基金the Laoshan Laboratory Science and Technology Innovation Project No.LSKJ202202104the National Nature Science Foundation of China No.42130406the Project of Doctoral Found of Qingdao University of Science and Technology under contract No.210010022746.
文摘Three extreme cold events occurred in eastern Asia in January 2016,January 2021,and December 2023.As important factors in atmospheric circulation anomalies,the Blocking High and East Asian Trough(BH-ET)structure played key roles during these three extreme cold wave events.Among these two dynamic patterns,the BH affected the development of the cold waves in two different ways:(1)before the cold waves in 2016 and 2023,the BH pushed the cold air southward,resulting in a slow and gradual cooling,with a cooling rate(CR)in eastern Asia of 1.34℃d^(-1)and 1.2℃d^(-1),respectively,and(2)in January 2021,the sudden collapse of BH caused the cold air to rapidly attack mid-latitude regions,with a CR of 1.87℃d^(-1).In terms of the spatial CR,the temperature drop in 2021 occurred 38.8%and 55%faster than those in 2016 and 2023,respectively.At the same time,the ET influences the wind direction of cold waves by modulating the pressure gradient.Before the cold waves occurred,the meridional wind field near the ET showed negative values,forming northwesterly or northeasterly winds,which continued to affect the southern part of East Asia.The meridional wind in January 2021 was stronger than those in 2016 and 2023,which is thought to be the reason for the strength of the 2021 cold wave.Finally,results from the temperature Empirical Orthogonal Function(EOF)analysis from 1980-2023 verify an obvious BH-ET structure in the three cold wave events,which suggests that this particular climatological state provides a climatic background for the occurrence of cold waves.
基金supported by the National Natural Science Foundation of China(No.24A20592).
文摘The Cambrian Qiongzhusi Formation in the Sichuan Basin harbors significant potential for shale gas harvesting.However,systematic disparities in mineral composition and reservoir architecture have been observed between intra-and extra-trough reservoirs within the Deyang-Anyue Rift Trough.These variations were primarily determined by divergences in the sedimentary environments developed during the evolution of the rift trough,which were a main factor in fostering the heterogeneous distribution of shale gas enrichment found today.However,the genetic mechanisms that govern reservoir heterogeneity across distinct structural domains(intra-trough,trough margin,and extra-trough)remain poorly understood,particularly regarding the coupling relationships between depositional environments,reservoir characteristics,and gas-bearing properties.This study adopts a multidisciplinary approach to investigating this issue that integrates core analysis,well-log interpretations,and geochemical data.Through systematic comparisons conducted using X-ray diffraction mineralogy,organic carbon quantification,and spontaneous imbibition experiments,we characterize the mineral assemblages,organic geochemical signatures,and pore structures found across the three structural domains of the Deyang-Anyue Rift Trough.The key findings are as follows:(1)The depositional environment is the main influence on reservoir distribution and organic matter enrichment,with intra-trough shales exhibiting a higher abundance of organic matter than their trough-margin and extra-trough counterparts.(2)Enhanced brittleness in intra-trough zones correlates with the predominance of biogenic silica therein.(3)Synergistic organic-inorganic interactions govern pore system development.(4)Gas-bearing capacity is jointly determined by effective porosity and organic matter content.These findings establish the rift trough as a preferential exploration target,providing critical geological guidance for optimizing shale gas exploration strategies in the Cambrian Qiongzhusi Formation.
基金Supported by the Key Project Plan of Health and Medical Science Research in Hebei Provincial Health Commission,No.20190745.
文摘BACKGROUND Plasma concentration monitoring is crucial for optimizing vancomycin use,particularly in patients in the intensive care unit(ICU).However,the reference interval for vancomycin plasma concentration remains undetermined.AIM To evaluate the correlations of area under the curve(AUC_(0-24))and trough concentration(C_(min))with efficacy and nephrotoxicity in patients in the ICU.METHODS A total of 103 patients treated with vancomycin for methicillin-resistant Staphylococcus aureus infections were analyzed in this study.The associations of clinicodemographic characteristics(including sex,age,weight,infection sites,main etiologies of ICU cases,comorbidities,acute physiological chronic health evaluation II score,and mechanical ventilation)and pharmacokinetics(daily dose,C_(min),AUC_(0-24),and AUC_(0-24)/minimum inhibitory concentration)with efficacy and nephrotoxicity of vancomycin were evaluated with univariate and multivariate logistic regression analyses.AUC_(0-24)was calculated using VCM-TDM software based on vancomycin population pharmacokinetics and Bayesian feedback method.RESULTS Cmin over 9.4μg/mL and AUC_(0-24)exceeding 359.6μg×hour/mL indicated good efficacy against infection.Cmin below 14.0μg/mL predicted no significant nephrotoxicity.CONCLUSION In this study,the effective and safe concentration interval for vancomycin in patients in the ICU was Cmin 9.4-14.0μg/mL.Close attention should be paid to adverse effects and renal function during vancomycin treatment.
基金Supported by the National Natural Science Foundation of China(42272161)PetroChina Science and Technology Major Project(2023ZZ16)Research Institute of Exploration and Development,PetroChina Southwest Oil&Gasfield Company(2024D101-01-06)。
文摘Taking the natural gas reservoirs of the Sinian Dengying Formation on the east and west sides(Gaoshiti-Moxi area and north slope of central Sichuan paleo-uplift on the east;Weiyuan and Well Datan-1 block on the west)of the Deyang-Anyue rift trough in the Sichuan Basin,China,as the research object,the geochemical parameters(component,isotopic composition)of natural gas from the Dengying Formation in different areas are compared,and then the differences in geochemical characteristics of Dengying natural gas on the east and west sides of the Deyang-Anyue rift trough and their genesis are clarified.First,the Dengying gas reservoirs on both sides of the rift trough are predominantly composed of oil-cracking gas with high maturity,which is typical dry gas.Second,severely modified by thermochemical sulfate reduction(TSR)reaction,the Dengying gas reservoirs on the east side exhibit high H2S and CO_(2) contents,with an elevated δ^(13)C_(2) value(average value higher than-29‰).The Dengying gas reservoirs in the Weiyuan area are less affected by TSR modification,though the δ^(13)C_(1) values are slightly greater than that of the reservoirs on the east side with partial reversal of carbon isotope composition,likely due to the water-soluble gas precipitation and accumulation mechanism.The Dengying gas reservoir of Well Datan-1 shows no influence from TSR.Third,the Dengying gas reservoirs reflect high helium contents(significantly higher than that on the east side)in the Weiyuan and Datan-1 areas on the west side,which is supposed to attribute to the widespread granites in basement and efficient vertical transport along faults.Fourth,controlled by the paleo-salinity of water medium in the depositional period of the source rock,the δ^(2)HCH_(4) values of the Dengying gas reservoirs on the west side are slightly lighter than those on the east side.Fifth,the Dengying natural gas in the Datan-1 area is contributed by the source rocks of the Sinian Doushantuo Formation and the third member of the Dengying Formation,in addition to the Cambrian Qiongzhusi Formation.
文摘The coal resources of Nigeria occur mainly within the Benue Trough which includes the Anambra Basin. In the Lower Benue Trough/Anambra Basin, sub-bituminous coals occur within the Maastrichtian Mamu Formation in Enugu （Enugu State）, Owukpa （Benue State）, Okaba （Kogi State） and Ogboyaga （Kogi State）. High-volatile bituminous coals occur within the Turonian-Coniacian Awgu Formation in the Middle Benue Trough around Obi/Lafia （Nasarawa State） with outcrop exposures at Jangwa-Shankodi. Organic petrographic results show that huminites dominate the maceral composition of the Anambra Basin coals and have vitrinite reflectance values that range from 0.40% to 0.63 Ro%. In the coals from the Middle Benue Trough, vitrinite macerals predominate the petrographic composition and Ro values range from 0.81% to 1.25%. Based on the petrographic composition and rank evaluation, the sub-bituminous coals in Enugu, Owukpa, Okaba and Ogboyaga （Anambra Basin） are optimum for combustion and electric power generation and sub-optimum for liquefaction, while the high-volatile bituminous coals in the Obi/Lafia area （Middle Benue Trough）, apart from being optimum for liquefaction, are the most suitable as raw material for coke making （carbonization） in steel manufacture and as exploration targets for coal-bed methane gas and liquid hydrocarbons.
文摘Based on the data of seismic reflection, seismic refraction and magnetism collected in the research area and geology obtained from adjacent areas, this paper deals with the issue of basement constitution of the southern part of the Okinawa Trough. In the shelf basin of the East China Sea, Taiwan folded belt and Ryukyu Islands folded belt which surround the trough, outcrop Later Paleozoic, Mesozoic and Eogene strata. In the southern trough, multichannel seismic reflection data indicate that the overlying strata are composed of Neogene and Quaternary deposits, and the acoustic basement consists of Eogent and even older strata. Seismic refraction profiles show that there are Eogene and Mesozoic velocity layers with longitudinal velocities of 4.7 - 5.3 km/s and 6.3 km/s respectively beneath the Quaternary-Miocene Layers. Qualitative analysis and forward and reversed calculation of magnetic data show that the magnetic basement is mainly formed by metamorphic rocks, the Yanshanian neutral-acid magmatic rocks and the Himalayan neutral-basic magmatic rocks being the next components, and the magnetic basement is mostly corresponding to the acoustic basement. Comprehensive analyses demonstrate that the basement of the southern Okinawa Trough is mainly formed by Eogene system and Mesozoic and Upper Paleozoic groups metamorphosed in varying degrees, and the basic magmatic rocks of Himalayan epoch have been formed in some parts of the basin.
