The potential of ALOS-2 SAR data for the estimation of tropical forest structural characteristics was assessed in Vietnam by collecting forest inventory data. The effect of polarization and seasonality of the SAR data...The potential of ALOS-2 SAR data for the estimation of tropical forest structural characteristics was assessed in Vietnam by collecting forest inventory data. The effect of polarization and seasonality of the SAR data on the estimation of forest biomass was analyzed. The combination of HH, HV, and HH/HV polarizations using multiple linear regression did not improve the estimation of biomass compared to using the HV channel independently, as the HH and HH/HV variables were not statistically significant. The dry season HV backscattering intensity was highly sensitive to the biomass compared to the rainy season backscattering intensity. The SAR data acquired in the rainy season with humid and wet canopies was not very sensitive to the biomass. The strong dependence of the biomass estimates with the season of SAR data acquisition confirmed that the choice of right season SAR data is very important for improving the satellite based estimates of the biomass. The validation results showed that the dry season HV polarization could explain 54% variation of the biomass.展开更多
等级保护2.0(以下简称“等保2.0”)对数据中心信息安全架构提出了合规与技术要求。文章构建四层联动架构模型,涵盖网络安全、计算环境、应用数据与安全运营4个层面,通过引入零信任访问控制、虚拟化隔离机制、数据全生命周期防护及安全...等级保护2.0(以下简称“等保2.0”)对数据中心信息安全架构提出了合规与技术要求。文章构建四层联动架构模型,涵盖网络安全、计算环境、应用数据与安全运营4个层面,通过引入零信任访问控制、虚拟化隔离机制、数据全生命周期防护及安全编排自动化响应(Security Orchestration Automation and Response,SOAR)机制,提出了一套面向等保2.0的优化实施方案。实验结果表明,优化架构在检测率、响应效率、资源占用等关键指标上相较传统架构均有显著提升。因此,优化架构具备良好的工程适配性与合规落地能力。展开更多
The increase in CO_(2)injectivity and shifting of CO_(2)-absorbing layers in multilayered geological CO_(2)sequestration(GCS)reservoirs in Ordos,China indicate significantpermeability variations in certain layers.To c...The increase in CO_(2)injectivity and shifting of CO_(2)-absorbing layers in multilayered geological CO_(2)sequestration(GCS)reservoirs in Ordos,China indicate significantpermeability variations in certain layers.To capture these system changes,a numerical model incorporating all 21 aquifers and internal aquitards was developed.The monitored pressure was well matched through multiphase and thermalhydraulic-mechanical(THM)coupling numerical simulations by introducing permeability variations.The results revealed that the permeability in the second layer increased on approximately day 13 due to the abrupt pressure buildup and temperature decrease.Even such a low rate of CO_(2)(2.8 kg/s)injected into the low permeability system initiated some fractures and the permeability in the second layer around the wellbore increased by 722 times.The second critical system change occurred on approximately day 386.As demonstrated in the numerical simulation,the substantial injection of cold CO_(2)induced strong thermal stress,leading to rock contraction and the initiation of several cracks.The permeability of the firstlayer around the wellbore unexpectedly increased by 4 orders of magnitude.Since no additional pressure could drive the CO_(2)into the remaining 17 layers,the total storage capability of the multilayered system was reduced.A whole picture of the system variation is fully presented and the underlying mechanisms are analyzed.It is believed that the phenomenon of thermal-hydraulic fracturing observed in this fieldand the simulation procedures will benefitother fluidinjection and production works in various geotechnical settings.展开更多
目的分析急性脑梗死患者沉默信息调节因子2(silent information regulator 2,SIRT2)与认知功能障碍发生及病情程度的关系。方法回顾性选择2022年5月至2024年5月武汉市第一医院神经内科收治的急性脑梗死合并认知功能障碍患者150例(研究...目的分析急性脑梗死患者沉默信息调节因子2(silent information regulator 2,SIRT2)与认知功能障碍发生及病情程度的关系。方法回顾性选择2022年5月至2024年5月武汉市第一医院神经内科收治的急性脑梗死合并认知功能障碍患者150例(研究组),研究组依据认知功能障碍严重程度分为轻度组45例、中度组66例和重度组39例。另选取同期武汉市第一医院就诊的急性脑梗死未合并认知功能障碍患者125例(对照组)。采用Spearman相关性分析血清SIRT2水平与认知功能障碍及病情程度的相关性,ROC曲线分析血清SIRT2水平对认知功能障碍及病情的评估价值,并计算曲线下面积(area under curve,AUC)。结果研究组血清SIRT2水平明显高于对照组,差异有统计学意义[(20.38±5.19)mg/L vs(14.66±4.49)mg/L,P<0.05]。重度组血清SIRT2水平明显高于中度组和轻度组,中度组血清SIRT2水平明显高于轻度组,差异有统计学意义(P<0.05)。Spearman相关性分析显示,血清SIRT2水平与认知功能障碍发生及严重程度呈正相关(r=0.510,r=0.527,P<0.01)。ROC曲线分析显示,血清SIRT2水平评估急性脑梗死患者认知功能障碍发生的AUC为0.796(95%CI:0.743~0.842),临界值为19.0 mg/L,敏感性为63.33%,特异性为84.00%;血清SIRT2水平评估急性脑梗死患者认知功能障碍严重程度的AUC为0.747(95%CI:0.655~0.824),临界值为17.2 mg/L,敏感性为75.76%,特异性为71.11%(P<0.05)。结论急性脑梗死患者血清SIRT2水平与认知功能障碍发生及病情密切相关。展开更多
Prostate cancer （PCa） is one of the most common cancers among men globally. The authors aimed to evaluate the ability of the Prostate Imaging Reporting and Data System version 2 （PI-RADS v2） to classify men with P...Prostate cancer （PCa） is one of the most common cancers among men globally. The authors aimed to evaluate the ability of the Prostate Imaging Reporting and Data System version 2 （PI-RADS v2） to classify men with PCa, clinically significant PCa （CSPCa）, or no PCa, especially among those with serum total prostate-specific antigen （tPSA） levels in the ＂gray zone＂ （4-10 ng ml-1）. A total of 308 patients （355 lesions） were enrolled in this study. Diagnostic efficiency was determined. Univariate and multivariate analyses, receiver operating characteristic curve analysis, and decision curve analysis were performed to determine and compare the predictors of PCa and CSPCa. The results suggested that PI-RADS v2, tPSA, and prostate-specific antigen density （PSAD） were independent predictors of PCa and CSPCa. A PI-RADS v2 score L≥4 provided high negative predictive values （91.39% for PCa and 95.69% for CSPCa）. A model of PI-RADS combined with PSA and PSAD helped to define a high-risk group （PI-RADS score = 5 and PSAD L≥0 15 ng ml-1 cm-3, with tPSA in the gray zone, or PI-RADS score L≥4 with high tPSA level） with a detection rate of 96.1% for PCa and 93.0% for CSPCa while a low-risk group with a detection rate of 6.1% for PCa and 2.2% for CSPCa. It was concluded that the PI-RADS v2 could be used as a reliable and independent predictor of PCa and CSPCa. The combination of PI-RADS v2 score with PSA and PSAD could be helpful in the prediction and diagnosis of PCa and CSPCa and, thus, may help in preventing unnecessary invasive procedures.展开更多
Atmospheric CO_(2)is one of key parameters to estimate air-sea CO_(2)flux.The Orbiting Carbon Observatory-2(OCO-2)satellite has observed the column-averaged dry-air mole fractions of global atmospheric carbon dioxide(...Atmospheric CO_(2)is one of key parameters to estimate air-sea CO_(2)flux.The Orbiting Carbon Observatory-2(OCO-2)satellite has observed the column-averaged dry-air mole fractions of global atmospheric carbon dioxide(XCO_(2))since 2014.In this study,the OCO-2 XCO_(2)products were compared between in-situ data from the Total Carbon Column Network(TCCON)and Global Monitoring Division(GMD),and modeling data from CarbonTracker2019 over global ocean and land.Results showed that the OCO-2 XCO_(2)data are consistent with the TCCON and GMD in situ XCO_(2)data,with mean absolute biases of 0.25×10^(-6)and 0.67×10^(-6),respectively.Moreover,the OCO-2 XCO_(2)data are also consistent with the CarbonTracker2019 modeling XCO_(2)data,with mean absolute biases of 0.78×10^(-6)over ocean and 1.02×10^(-6)over land.The results indicated the high accuracy of the OCO-2 XCO_(2)product over global ocean which could be applied to estimate the air-sea CO_(2)flux.展开更多
文摘The potential of ALOS-2 SAR data for the estimation of tropical forest structural characteristics was assessed in Vietnam by collecting forest inventory data. The effect of polarization and seasonality of the SAR data on the estimation of forest biomass was analyzed. The combination of HH, HV, and HH/HV polarizations using multiple linear regression did not improve the estimation of biomass compared to using the HV channel independently, as the HH and HH/HV variables were not statistically significant. The dry season HV backscattering intensity was highly sensitive to the biomass compared to the rainy season backscattering intensity. The SAR data acquired in the rainy season with humid and wet canopies was not very sensitive to the biomass. The strong dependence of the biomass estimates with the season of SAR data acquisition confirmed that the choice of right season SAR data is very important for improving the satellite based estimates of the biomass. The validation results showed that the dry season HV polarization could explain 54% variation of the biomass.
文摘等级保护2.0(以下简称“等保2.0”)对数据中心信息安全架构提出了合规与技术要求。文章构建四层联动架构模型,涵盖网络安全、计算环境、应用数据与安全运营4个层面,通过引入零信任访问控制、虚拟化隔离机制、数据全生命周期防护及安全编排自动化响应(Security Orchestration Automation and Response,SOAR)机制,提出了一套面向等保2.0的优化实施方案。实验结果表明,优化架构在检测率、响应效率、资源占用等关键指标上相较传统架构均有显著提升。因此,优化架构具备良好的工程适配性与合规落地能力。
基金supports from the National Natural Science Foundation of China(Grant Nos.52179095,52378323,and 42407216)are gratefully acknowledged.
文摘The increase in CO_(2)injectivity and shifting of CO_(2)-absorbing layers in multilayered geological CO_(2)sequestration(GCS)reservoirs in Ordos,China indicate significantpermeability variations in certain layers.To capture these system changes,a numerical model incorporating all 21 aquifers and internal aquitards was developed.The monitored pressure was well matched through multiphase and thermalhydraulic-mechanical(THM)coupling numerical simulations by introducing permeability variations.The results revealed that the permeability in the second layer increased on approximately day 13 due to the abrupt pressure buildup and temperature decrease.Even such a low rate of CO_(2)(2.8 kg/s)injected into the low permeability system initiated some fractures and the permeability in the second layer around the wellbore increased by 722 times.The second critical system change occurred on approximately day 386.As demonstrated in the numerical simulation,the substantial injection of cold CO_(2)induced strong thermal stress,leading to rock contraction and the initiation of several cracks.The permeability of the firstlayer around the wellbore unexpectedly increased by 4 orders of magnitude.Since no additional pressure could drive the CO_(2)into the remaining 17 layers,the total storage capability of the multilayered system was reduced.A whole picture of the system variation is fully presented and the underlying mechanisms are analyzed.It is believed that the phenomenon of thermal-hydraulic fracturing observed in this fieldand the simulation procedures will benefitother fluidinjection and production works in various geotechnical settings.
基金国家自然科学基金项目“青藏高原露天煤矿排土场地形-土壤-植被响应机理及地貌重塑研究”(编号:41977415)中国地质调查局项目“全球冰川及荒漠化遥感地质调查”(编号:DD20190515)+1 种基金中欧科技合作“龙计划”五期项目“Integration of multi-source Remote Sensing Data to detect and monitoring large and rapid landslides and use of Artificial Intelligence for Cultural Heritage preservation”(编号:56796)JAXA EO-RA2项目“Application of Radar Remote Sensing Technology in Resource Environment Monitoring”(编号:P3073002)共同资助。
文摘目的分析急性脑梗死患者沉默信息调节因子2(silent information regulator 2,SIRT2)与认知功能障碍发生及病情程度的关系。方法回顾性选择2022年5月至2024年5月武汉市第一医院神经内科收治的急性脑梗死合并认知功能障碍患者150例(研究组),研究组依据认知功能障碍严重程度分为轻度组45例、中度组66例和重度组39例。另选取同期武汉市第一医院就诊的急性脑梗死未合并认知功能障碍患者125例(对照组)。采用Spearman相关性分析血清SIRT2水平与认知功能障碍及病情程度的相关性,ROC曲线分析血清SIRT2水平对认知功能障碍及病情的评估价值,并计算曲线下面积(area under curve,AUC)。结果研究组血清SIRT2水平明显高于对照组,差异有统计学意义[(20.38±5.19)mg/L vs(14.66±4.49)mg/L,P<0.05]。重度组血清SIRT2水平明显高于中度组和轻度组,中度组血清SIRT2水平明显高于轻度组,差异有统计学意义(P<0.05)。Spearman相关性分析显示,血清SIRT2水平与认知功能障碍发生及严重程度呈正相关(r=0.510,r=0.527,P<0.01)。ROC曲线分析显示,血清SIRT2水平评估急性脑梗死患者认知功能障碍发生的AUC为0.796(95%CI:0.743~0.842),临界值为19.0 mg/L,敏感性为63.33%,特异性为84.00%;血清SIRT2水平评估急性脑梗死患者认知功能障碍严重程度的AUC为0.747(95%CI:0.655~0.824),临界值为17.2 mg/L,敏感性为75.76%,特异性为71.11%(P<0.05)。结论急性脑梗死患者血清SIRT2水平与认知功能障碍发生及病情密切相关。
文摘Prostate cancer （PCa） is one of the most common cancers among men globally. The authors aimed to evaluate the ability of the Prostate Imaging Reporting and Data System version 2 （PI-RADS v2） to classify men with PCa, clinically significant PCa （CSPCa）, or no PCa, especially among those with serum total prostate-specific antigen （tPSA） levels in the ＂gray zone＂ （4-10 ng ml-1）. A total of 308 patients （355 lesions） were enrolled in this study. Diagnostic efficiency was determined. Univariate and multivariate analyses, receiver operating characteristic curve analysis, and decision curve analysis were performed to determine and compare the predictors of PCa and CSPCa. The results suggested that PI-RADS v2, tPSA, and prostate-specific antigen density （PSAD） were independent predictors of PCa and CSPCa. A PI-RADS v2 score L≥4 provided high negative predictive values （91.39% for PCa and 95.69% for CSPCa）. A model of PI-RADS combined with PSA and PSAD helped to define a high-risk group （PI-RADS score = 5 and PSAD L≥0 15 ng ml-1 cm-3, with tPSA in the gray zone, or PI-RADS score L≥4 with high tPSA level） with a detection rate of 96.1% for PCa and 93.0% for CSPCa while a low-risk group with a detection rate of 6.1% for PCa and 2.2% for CSPCa. It was concluded that the PI-RADS v2 could be used as a reliable and independent predictor of PCa and CSPCa. The combination of PI-RADS v2 score with PSA and PSAD could be helpful in the prediction and diagnosis of PCa and CSPCa and, thus, may help in preventing unnecessary invasive procedures.
基金The National Key Research and Development Programme of China under contract No.2017YFA0603004the Fund of Southern Marine Science and Engineering Guangdong Laboratory(Zhanjiang)(Zhanjiang Bay Laboratory)under contract No.ZJW-2019-08+1 种基金the National Natural Science Foundation of China under contract Nos 41825014,41676172 and 41676170the Global Change and Air-Sea Interaction Project of China under contract Nos GASI-02-SCS-YGST2-01,GASI-02-PACYGST2-01 and GASI-02-IND-YGST2-01。
文摘Atmospheric CO_(2)is one of key parameters to estimate air-sea CO_(2)flux.The Orbiting Carbon Observatory-2(OCO-2)satellite has observed the column-averaged dry-air mole fractions of global atmospheric carbon dioxide(XCO_(2))since 2014.In this study,the OCO-2 XCO_(2)products were compared between in-situ data from the Total Carbon Column Network(TCCON)and Global Monitoring Division(GMD),and modeling data from CarbonTracker2019 over global ocean and land.Results showed that the OCO-2 XCO_(2)data are consistent with the TCCON and GMD in situ XCO_(2)data,with mean absolute biases of 0.25×10^(-6)and 0.67×10^(-6),respectively.Moreover,the OCO-2 XCO_(2)data are also consistent with the CarbonTracker2019 modeling XCO_(2)data,with mean absolute biases of 0.78×10^(-6)over ocean and 1.02×10^(-6)over land.The results indicated the high accuracy of the OCO-2 XCO_(2)product over global ocean which could be applied to estimate the air-sea CO_(2)flux.
