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Clinical Value of Hepatitis B Virus RNA Detection in Patients with Chronic Hepatitis B Infection
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作者 Yu Li Yifei Lyu Feng-Yu Xi 《Proceedings of Anticancer Research》 2023年第4期29-32,共4页
Objective:To study the clinical value of hepatitis B virus pregenomic RNA(HBV-pgRNA)detection in the treatment of hepatitis B.Methods:60 patients with hepatitis B were included in the study.Serum HBV-pgRNA and HBV DNA... Objective:To study the clinical value of hepatitis B virus pregenomic RNA(HBV-pgRNA)detection in the treatment of hepatitis B.Methods:60 patients with hepatitis B were included in the study.Serum HBV-pgRNA and HBV DNA levels in different phases of infection and during treatment were detected,and serum hepatitis B surface antigen(HbsAg)titer was detected by chemiluminescent immunoassay.DNA was extracted from liver biopsy tissue,and covalently closed circular DNA was detected to predict the therapeutic value in patients.Results:At the initial stage of treatment,the level of HBV-pgRNA in phase I,II,III,and IV showed a gradual decrease.Comparing the levels of HBV-pgRNA before and after treatment,we found that the level of HBV-pgRNA was significantly lower after treatment(P<0.05).Among the indicators for predicting HBsAg seroconversion,the accuracy of HBV-pgRNA level was 85.0%(51/60).Conclusion:The clinical value of HBV-pgRNA detection in the treatment of hepatitis B is high. 展开更多
关键词 Hepatitis b virus pregenomic RNA HbV-pgRNA Detection Hepatitis b Treatment Clinical value
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Predictive Value of Serum pgRNA on HBeAg Clearance in Patients with Chronic Hepatitis B with Low HBeAg Levels Treated with Pegylated Interferon
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作者 Yu Li Yifei Lyu +1 位作者 Feng-Yu Xi Ying Gao 《Journal of Clinical and Nursing Research》 2023年第4期165-169,共5页
Objective:To study the predictive value of serum pregenomic RNA(pgRNA)on HBeAg clearance in patients with chronic hepatitis B with low HBeAg levels during pegylated interferon therapy.Methods:Twenty chronic hepatitis ... Objective:To study the predictive value of serum pregenomic RNA(pgRNA)on HBeAg clearance in patients with chronic hepatitis B with low HBeAg levels during pegylated interferon therapy.Methods:Twenty chronic hepatitis B patients with HBeAg positive and quantitative<50S/CO were selected for this study.The subjects underwent pegylated interferon therapy for 48-96 weeks and were followed up in the outpatient clinic after treatment.The patients were then divided into groups based on whether their HbeAg turned negative.The predictive ability of each indicator for HBeAg negative conversion was evaluated in the HBeAg negative group and the HBeAg positive group.Results:The results of logistic regression analysis suggested that pgRNA and HBcrAg were better indicators for predicting the clearance of HBeAg after treatment.Conclusion:For patients with chronic hepatitis B with low HBeAg levels,pgRNA is a good indicator in predicting HBeAg clearance during pegylated interferon therapy. 展开更多
关键词 Serum pgRNA Pegylated interferon Low HbeAg level Chronic hepatitis b HbeAg clearance Predictive value
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地震统计区地震活动性参数b值和ν_(4)计算分析−以华北地区为例
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作者 沈得秀 王庆民 +2 位作者 许洪泰 葛孚刚 蒋其峰 《震灾防御技术》 CSCD 北大核心 2024年第2期241-252,共12页
本文通过收集最新现代地震资料,采用历史地震与现代地震联合求取地震活动性参数的方法,按不同地震统计时段和震级段,基于Matlab程序中给定函数计算并拟合了华北平原地震统计区、郯庐地震统计区、长江下游-南黄海地震统计区、汾渭地震统... 本文通过收集最新现代地震资料,采用历史地震与现代地震联合求取地震活动性参数的方法,按不同地震统计时段和震级段,基于Matlab程序中给定函数计算并拟合了华北平原地震统计区、郯庐地震统计区、长江下游-南黄海地震统计区、汾渭地震统计区的b值和ν_(4),并将结果与五代图推荐的b值和ν_(4)进行地震危险性分析对比,进而分析最新现代地震资料对b值和ν_(4)的影响。研究结果对地震统计区确定b值和ν_(4)有一定参考意义,对地震区划、工程场地地震安全性评价、省级地震危险性区划编制工作具有实际意义。 展开更多
关键词 地震活动性参数 b ν_(4) 华北地区
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唐山老震区M≥4.0地震前b值变化异常特征研究
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作者 岳晓媛 李艳娥 +3 位作者 钟世军 王薇 王燕 马梁 《地震》 CSCD 北大核心 2024年第1期94-108,共15页
选取2009年1月至2022年12月唐山老震区的地震目录资料计算b值,利用格点搜索法确定b值下降幅度较大(≥20%)的区域作为异常区,分析该区域b值的时间变化特征,结合b值的时空变化研究该区域发生M4.0以上地震的危险性。研究发现,唐山老震区7次... 选取2009年1月至2022年12月唐山老震区的地震目录资料计算b值,利用格点搜索法确定b值下降幅度较大(≥20%)的区域作为异常区,分析该区域b值的时间变化特征,结合b值的时空变化研究该区域发生M4.0以上地震的危险性。研究发现,唐山老震区7次(组)M4.0以上地震均发生在b值下降幅度较大的区域边缘或附近,表明应力较高的区域是地震危险区。异常区域内b值的时间变化显示,7次(组)M4.0以上地震多在震前半年至一年出现b值下降的变化过程,也反映了异常区域应力逐渐积累的过程。总体来说,b值的时空下降变化对唐山老震区M4.0以上地震的研判具有指示意义。 展开更多
关键词 唐山老震区 异常特征 b 格点搜索
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基于声发射b值分析的风力机叶片材料损伤特性研究
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作者 廖力达 陆正鹏 +3 位作者 叶捍 黄斌 舒王咏 张芝铭 《太阳能学报》 EI CAS CSCD 北大核心 2024年第2期172-180,共9页
风力发电机叶片主要材料玻璃纤维环氧树脂增强复合材料(GFRP)的损伤,会造成叶片寿命减少甚至断裂,必须进行损伤检测。采用声发射方法可分析GFRP复合材料损伤特性,实现在线监测叶片性能。该文采用声发射b值特征来表征GFRP损伤程度,并通... 风力发电机叶片主要材料玻璃纤维环氧树脂增强复合材料(GFRP)的损伤,会造成叶片寿命减少甚至断裂,必须进行损伤检测。采用声发射方法可分析GFRP复合材料损伤特性,实现在线监测叶片性能。该文采用声发射b值特征来表征GFRP损伤程度,并通过主成分分析和k-均值++算法进行声发射参数聚类来分析GFRP损坏模式。结果表明:1)对整个声发射事件进行b值分析,观察到GFRP试样在断裂前b值呈明显下降趋势,表明b值的变化率可作为材料断裂的预警信号。2)根据主成分分析9种声发射参数所占主成分比重,选择声发射信号的幅度、峰值频率两个特征参数。通过k-均值++算法对特征参数进行聚类分析,发现拉伸过程的声发射信号分为了4个簇,并找到每个簇的特征频率。3)通过使用扫描电子显微镜(SEM)对GFRP试样拉伸断口进行观察,得到4个簇分别对应于基体开裂、纤维/基体脱粘、分层和纤维断裂4种损伤模式。基于声发射b值分析方法适用于GFRP损伤特性研究,可在风力发电机叶片损伤检测领域推广。 展开更多
关键词 风力机叶片 声发射 复合材料 b值分析
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乙肝肝硬化失代偿期并发肝功能衰竭患者血清Autotaxin、Copeptin、LBP与预后的关系研究
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作者 张帆 毛屏 +2 位作者 张晨 金星 李丹 《现代消化及介入诊疗》 2024年第5期534-538,共5页
目的探讨乙肝肝硬化失代偿期(HBV-DC)并发肝功能衰竭(LF)患者血清自分泌运动因子(Autotaxin)、和肽素(Copeptin)、内毒素结合蛋白(LBP)与预后的关系。方法选取2018年2月至2023年8月我院收治的143例HBV-DC并发LF患者为研究对象,随访90 d... 目的探讨乙肝肝硬化失代偿期(HBV-DC)并发肝功能衰竭(LF)患者血清自分泌运动因子(Autotaxin)、和肽素(Copeptin)、内毒素结合蛋白(LBP)与预后的关系。方法选取2018年2月至2023年8月我院收治的143例HBV-DC并发LF患者为研究对象,随访90 d,根据预后情况分组为死亡组(55例)与存活组(88例),比较两组血清Autotaxin、Copeptin、LBP水平。收集HBV-DC并发LF患者的临床资料,采用单因素和多因素Logistic回归模型分析HBV-DC并发LF患者预后的影响因素。采用受试者工作特征(ROC)曲线分析血清Autotaxin、Copeptin、LBP单独或联合预测HBV-DC并发LF患者预后的临床价值。结果143例HBV-DC并发LF患者随访90 d时,有55例死亡,88例存活,死亡率38.46%。与存活组比较,死亡组血清Autotaxin、Copeptin、LBP水平明显增加(P<0.05)。与存活组比较,死亡组住院时间≥14 d比例、并发腹水比例、并发肝性脑病比例、谷丙转氨酶、总胆红素、终末期肝病模型(MELD)评分显著升高(P<0.05),白蛋白显著降低(P<0.05),年龄、性别、合并糖尿病、合并高血压、血肌酐、血小板计数、纤维蛋白原无显著性差异(P>0.05)。总胆红素升高、并发肝性脑病、MELD评分升高以及血清Autotaxin、Copeptin、LBP水平升高均为HBV-DC并发LF患者预后不良的危险因素(P<0.05)。ROC曲线结果显示,血清Autotaxin、LBP、Copeptin标联合检测预测HBV-DC并发LF患者预后不良的曲线下面积(AUC)、灵敏度、特异度分别为0.930、85.45%、88.64%,显著优于单项指标检测预测的效能。结论血清Autotaxin、Copeptin、LBP高表达与HBV-DC并发LF患者短期死亡发生风险有关,且联合检测对HBV-DC并发LF患者短期死亡的发生具有较高的临床预测价值。 展开更多
关键词 乙肝肝硬化失代偿期 肝功能衰竭 自分泌运动因子 和肽素 内毒素结合蛋白 预后 预测价值
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NT-proBNP、D-D、CRP检测在中老年急性脑梗死患者中的临床诊断价值分析 被引量:1
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作者 张伟 《中国实用医药》 2024年第10期81-84,共4页
目的 分析氨基末端脑钠肽前体(NT-proBNP)、D-二聚体(D-D)、C反应蛋白(CRP)检测对中老年急性脑梗死(ACI)患者的诊断价值。方法 选取中老年急性脑梗死患者52例为观察组[根据病灶直径不同分为大面积梗死组(>5 cm)10例、中面积梗死组(≤... 目的 分析氨基末端脑钠肽前体(NT-proBNP)、D-二聚体(D-D)、C反应蛋白(CRP)检测对中老年急性脑梗死(ACI)患者的诊断价值。方法 选取中老年急性脑梗死患者52例为观察组[根据病灶直径不同分为大面积梗死组(>5 cm)10例、中面积梗死组(≤5 cm,>3 cm)16例、小面积梗死组(≤3 cm,>1.5 cm)26例],另选取健康体检者50例为对照组。观察组及对照组均进行D-D、CRP、NT-proBNP水平检测。比较观察组及对照组的CRP、D-D、NT-proBNP水平,观察组不同脑梗死面积患者的CRP、D-D、NT-proBNP水平。结果观察组CRP、D-D、NT-proBNP水平均高于对照组,差异具有统计学意义(P<0.05)。观察组中,大面积梗死组的NT-proBNP、D-D、CRP水平分别为(3351.70±940.97)pg/ml、(898.43±323.19)ng/ml、(41.79±11.08)mg/L,中面积梗死组的NT-proBNP、D-D、CRP水平分别为(1338.06±345.23)pg/ml、(573.88±312.67)ng/ml、(32.05±11.77)mg/L,小面积梗死组的NT-proBNP、D-D、CRP水平分别为(447.00±195.72)pg/ml、(334.15±229.81)ng/ml、(18.03±10.14)mg/L。大面积梗死组患者的NT-proBNP、D-D、CRP水平均高于中面积梗死组及小面积梗死组,中面积梗死组患者的NT-proBNP、D-D、CRP水平均高于小面积梗死组,差异具有统计学意义(P<0.05)。结论 D-D、CRP、NT-proBNP在诊断中老年急性脑梗死患者中存在较高的应用价值。 展开更多
关键词 D-二聚体 C反应蛋白 氨基末端脑钠肽前体 急性脑梗死 诊断价值
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基于声发射断层总面积和b值的钢筋混凝土梁损伤表征
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作者 顾爱军 关庆圆 +2 位作者 徐波 苏铭 李非凡 《中国测试》 CAS 北大核心 2024年第7期147-154,198,共9页
为研究钢筋混凝土构件破坏过程中的声发射特性,对钢筋混凝土梁进行四点弯曲加载破坏试验,利用声发射技术对破坏过程进行监测。为综合考虑声发射信号的事件数、幅度和能量等因素所反映的损伤特性,引用地震学领域的断层总面积理论与声发射... 为研究钢筋混凝土构件破坏过程中的声发射特性,对钢筋混凝土梁进行四点弯曲加载破坏试验,利用声发射技术对破坏过程进行监测。为综合考虑声发射信号的事件数、幅度和能量等因素所反映的损伤特性,引用地震学领域的断层总面积理论与声发射b值理论进行联合表征。断层总面积反映事件数和能量的关系,声发射b值反映事件数和幅度的关系,两者的结合可以更好地反映钢筋混凝土梁的破坏规律。实验表明,该损伤表征方法可进一步提升对混凝土结构损伤预警识别的精准性,从而在实际工程运用声发射技术进行损伤识别和预警提出合理的声发射信号监测方法。 展开更多
关键词 钢筋混凝土梁 声发射 b 断层总面积
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急性阵发性房颤患者基线NT-proBNP对胺碘酮复律疗效的影响
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作者 邓水清 黄小辉 《中国卫生标准管理》 2024年第10期142-145,共4页
目的 探讨N末端B型利钠肽原(N-terminal pro B-type natriuretic peptide,NT-proBNP)在胺碘酮用于急性阵发性房颤(acute atrial fibrillation,AF)复律疗效评估中的价值。方法纳入2019年2月—2022年7月三明市第二医院急诊科明确诊断为AF... 目的 探讨N末端B型利钠肽原(N-terminal pro B-type natriuretic peptide,NT-proBNP)在胺碘酮用于急性阵发性房颤(acute atrial fibrillation,AF)复律疗效评估中的价值。方法纳入2019年2月—2022年7月三明市第二医院急诊科明确诊断为AF(非瓣膜病)的68例患者,所有患者排除禁忌后均给予胺碘酮复律治疗,根据复律后转复情况分为2组,即成功转复组(n=57)与转复失败组(n=11)。对比2组症状与体征(心悸、胸痛)、心电图表现(是否合并ST段压低)、既往病史(是否合并糖尿病、高血压病、冠心病等)、房颤持续时间和基线NT-proBNP水平。采用二元logistic回归分析AF患者胺碘酮复律疗效的影响因素。结果 2组胸痛、合并糖尿病、合并冠心病、ST段压低、房颤持续时间、合并高血压比较,差异无统计学意义(P>0.05)。成功转复组心悸发生率为28.07%、NT-proBNP水平为(229.43±7.24)pmol/L,优于转复失败组的63.64%、(679.99±8.67)pmol/L,差异有统计学意义(P<0.05)。入院时存在心悸症状、NT-proBNP是影响AF患者应用胺碘酮转复的主要因素(P<0.05)。结论 胺碘酮对AF(非瓣膜病)患者复律治疗安全有效,入院时存在心悸症状、基线NT-proBNP水平是预测胺碘酮复律成功的重要因素。 展开更多
关键词 N末端b型利钠肽原 胺碘酮 房颤 复律 非瓣膜病 评估价值
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CTRP3联合NT-proBNP对MVD患者发生HHcy的预测价值
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作者 李欣 张明亮 +2 位作者 曲超 邢丽婷 王嵬民 《中国实用医药》 2024年第3期68-71,共4页
目的探讨补体C1q/肿瘤坏死因子相关蛋白3(CTRP3)联合N末端B型利钠肽前体(NT-proBNP)对冠状动脉(冠脉)多支病变(MVD)患者发生高同型半胱氨酸血症(HHcy)的预测价值。方法回顾性分析200例MVD患者的临床资料,根据血浆同型半胱氨酸(Hcy)水平... 目的探讨补体C1q/肿瘤坏死因子相关蛋白3(CTRP3)联合N末端B型利钠肽前体(NT-proBNP)对冠状动脉(冠脉)多支病变(MVD)患者发生高同型半胱氨酸血症(HHcy)的预测价值。方法回顾性分析200例MVD患者的临床资料,根据血浆同型半胱氨酸(Hcy)水平是否>15μmol/L分为高Hcy组(111例)和正常Hcy组(89例)。比较两组基线资料[年龄、性别、冠心病病程、吸烟史、糖尿病病史、高血压病史、体质量指数(BMI)],生化指标(NT-proBNP、尿酸(UA)、甘油三酯(TG)、总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)、Hcy、CTRP3),采用二元Logistic回归分析法分析影响MVD患者发生HHcy危险因素,绘制受试者工作特征(ROC)曲线分析CTRP3联合NT-proBNP对MVD患者发生HHcy的预测效能。结果两组年龄、高血压病史、BMI、UA、TG、TC、HDL-C比较均无统计学差异(P>0.05);高Hcy组男性患者数量70例、冠心病病程(6.66±4.49)年、吸烟史55例、糖尿病病史60例,均大于正常Hcy组的36例、(3.67±2.31)年、28例、17例,NT-proBNP(5234.95±7476.76)pg/ml、LDL-C(3.55±0.95)mmol/L、Hcy(44.75±12.48)μmol/L均高于正常Hcy组的(1296.94±3864.78)pg/ml、(2.95±0.88)mmol/L、(10.58±2.80)μmol/L,CTRP3(65.20±13.61)μg/L低于正常Hcy组的(88.69±14.94)μg/L,两组间比较差异均具有统计学意义(P<0.05)。多因素Logistic回归分析显示:男性[OR=3.745,95%CI=(1.398,10.030)]、糖尿病病史[OR=3.262,95%CI=(1.264,8.417)]、冠心病病程[OR=1.194,95%CI=(1.022,1.394)]、LDL-C[OR=2.254,95%CI=(1.337,3.800)]为导致MVD患者发生HHcy的独立危险因素,而CTRP3[OR=0.902,95%CI=(0.873,0.933)]为其独立保护因素(P<0.05)。ROC曲线结果显示:CTRP3联合NT-proBNP预测MVD患者发生HHcy的AUC为0.901,敏感度为83.8%,特异度为86.5%,优于LDL-C、NT-proBNP或CTRP3单独预测(P<0.05)。结论性别、糖尿病病史、冠心病病程、LDL-C为导致MVD患者发生HHcy的独立危险因素,而CTRP3为其独立保护因素。血清CTRP3联合NT-proBNP可提高MVD患者发生HHcy的预测价值。 展开更多
关键词 冠状动脉多支病变 高同型半胱氨酸血症 N末端b型利钠肽前体 补体C1q/肿瘤坏死因子相关蛋白3 预测价值
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Importance of b value in diffusion weighted imaging for the diagnosis of pancreatic cancer 被引量:12
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作者 Jin-Gang Hao Jia-Ping Wang +1 位作者 Ya-Lv Gu Ming-Liang Lu 《World Journal of Gastroenterology》 SCIE CAS 2013年第39期6651-6655,共5页
AIM:To investigate the use of multi-b-value diffusionweighted imaging in diagnosing pancreatic cancer.METHODS:We retrospectively analyzed 33 cases of pancreatic cancer and 12 cases of benign pancreatic tumors at the S... AIM:To investigate the use of multi-b-value diffusionweighted imaging in diagnosing pancreatic cancer.METHODS:We retrospectively analyzed 33 cases of pancreatic cancer and 12 cases of benign pancreatic tumors at the Second Affiliated Hospital of Kunming Medical University from December 2008 to January2011.The demographic characteristics,clinical presentation,routine magnetic resonance imaging and diffusion weighted imaging(DWI)features with different b values were reviewed.Continuous data were expressed as mean±SD.Comparisons between pancreatic cancer and benign pancreatic tumors were performed using the Student’s t test.A probability of P<0.05 was considered statistically significant.RESULTS:Thirty-three patients with pancreatic cancer were identified.The mean age at diagnosis was 60±5.6 years.The male:female ratio was 21:12.Twenty cases were confirmed by surgical resection and 13 by biopsy of metastases.T1 weighted images demonstrated a pancreatic head mass in 16 patients,a pancreatic body mass in 10 cases,and a pancreatic tail mass with pancreatic atrophy in 7 cases.Eight patients had hepatic metastases,13 had invasion or envelopment of mesenteric vessels,4 had bone metastases,and 8had lymph node metastases.DWI demonstrated an irregular intense mass with unclear margins.Necrotic tissue demonstrated an uneven low signal.A b of 1100s/mm2was associated with a high intensity signal with poor anatomical delineation.A b of 700 s/mm2was associated with apparent diffusion coefficients(ADCs)that were useful in distinguishing benign and malignant pancreatic tumors(P<0.05).b values of 50,350,400,450 and 1100 s/mm2were associated with ADCs that did not differentiate the two tumors.CONCLUSION:Low b value images demonstrated superior anatomical details when compared to high b value images.Tumor tissue definition was high and contrast with the surrounding tissues was good.DWI was useful in diagnosing pancreatic cancer. 展开更多
关键词 PANCREATIC cancer Magnetic resonance IMAGING b value APPARENT DIFFUSION coefficient DIFFUSION weighted IMAGING
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Optimal b value of diffusion-weighted imaging on a 3.0T magnetic resonance scanner in Crohn's disease 被引量:4
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作者 Qi Feng Yun-Qi Yan +2 位作者 Jiong Zhu Jin-Lu Tong Jian-Rong Xu 《World Journal of Gastroenterology》 SCIE CAS 2014年第35期12621-12627,共7页
AIM: To determine the optimal b value of diffusion-weighted imaging for detecting active inflammation in Crohn&#x02019;s disease.
关键词 Crohn’ s disease Diffusion-weighted imaging b value Magnetic resonance image 3.0 Tesla
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Prognostic value of M30/M65 for outcome of hepatitis B virus-related acute-on-chronic liver failure 被引量:14
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作者 Su-Jun Zheng Shuang Liu +7 位作者 Mei Liu Malcolm A McCrae Jun-Feng Li Yuan-Ping Han Chun-Hui Xu Feng Ren Yu Chen Zhong-Ping Duan 《World Journal of Gastroenterology》 SCIE CAS 2014年第9期2403-2411,共9页
AIM: To determine the prognostic value of circulating indicators of cell death in acute-on-chronic liver failure (ACLF) patients with chronic hepatitis B virus (HBV) infection as the single etiology. METHODS: Full len... AIM: To determine the prognostic value of circulating indicators of cell death in acute-on-chronic liver failure (ACLF) patients with chronic hepatitis B virus (HBV) infection as the single etiology. METHODS: Full length and caspase cleaved cytokeratin 18 (detected as M65 and M30 antigens) represent circulating indicators of necrosis and apoptosis. M65 and M30 were identified by enzyme-linked immunosorbent assay in 169 subjects including healthy controls (n = 33), patients with chronic hepatitis B (CHB, n = 55) and patients with ACLF (n = 81). According to the 3-mo survival period, ACLF patients were defined as having spontaneous recovery (n = 33) and non-spontaneous recovery which included deceased patients and those who required liver transplantation (n = 48). RESULTS: Both biomarker levels significantly increased gradually as liver disease progressed (for M65: P < 0.001 for all; for M30: control vs CHB, P = 0.072; others: P < 0.001 for all). In contrast, the M30/M65 ratio was significantly higher in controls compared with CHB patients (P = 0.010) or ACLF patients (P < 0.001). In addition, the area under receiver operating characteristic curve (AUC) analysis demonstrated that both biomarkers had diagnostic value (AUC >= 0.80) in identifying ACLF from CHB patients. Interestingly, it is worth noting that the M30/M65 ratio was significantly different between spontaneous and non-spontaneous recovery in ACLF patients (P = 0.032). The prognostic value of the M30/M65 ratio was compared with the Model for End-Stage Liver Disease (MELD) and Child-Pugh scores at the 3-mo survival period, the AUC of the M30/M65 ratio was 0.66 with a sensitivity of 52.9% and the highest specificity of 92.6% (MELD:AUC = 0.71; sensitivity, 79.4%; specificity, 63.0%; Child-Pugh: AUC = 0.77; sensitivity, 61.8%; specificity, 88.9%). CONCLUSION: M65 and M30 are strongly associated with liver disease severity. The M30/M65 ratio may be a potential prognostic marker for spontaneous recovery in patients with HBV-related ACLF. (C) 2014 Baishideng Publishing Group Co., Limited. All rights reserved. 展开更多
关键词 Acute-on-chronic liver failure Chronic hepatitis b virus infection Liver disease stage Liver disease severity Serum M65 level Serum M30 level Prognostic value
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2022年9月5日四川泸定6.8级地震及其余震前后b值变化
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作者 李蒙亚 曾宪伟 +3 位作者 姚华建 李新艳 张志 杨硕 《地震工程学报》 CSCD 北大核心 2024年第5期1214-1222,共9页
收集2012年1月1日—2023年2月8日四川泸定地区(29.28°~30.04°N,101.82°~102.28°E)记录的地震资料,利用最大似然法进行b值的空间扫描,揭示泸定主震区及周边区域b值的时空变化特征。计算结果显示,2022年泸定6.8级地震... 收集2012年1月1日—2023年2月8日四川泸定地区(29.28°~30.04°N,101.82°~102.28°E)记录的地震资料,利用最大似然法进行b值的空间扫描,揭示泸定主震区及周边区域b值的时空变化特征。计算结果显示,2022年泸定6.8级地震前5个月,主震区及其东南区b值出现加速下降变化,可能预示着局部岩石受力变形接近临界状态;5.6级强余震前,震中区b值仍然维持低值异常,显示出区域内的应力水平仍然偏高,预示着可能会发生强余震;5.6级余震发生后,异常区域明显缩小但未消失,预示着余震可能还将持续,但再次发生强余震的可能性较小。 展开更多
关键词 泸定地震 b 极大似然法 地震危险性
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A discussion on the application of b-value to the prediction of seismic tendency 被引量:21
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作者 吴忠良 《地震学报》 CSCD 北大核心 2001年第5期548-551,共4页
In the estimation of seismic tendency, using Gutenberg-Richters b-value and using Hurst exponent are two com-monly used methods. Based on the fractal geometry of earthquake time series, we point out that these two met... In the estimation of seismic tendency, using Gutenberg-Richters b-value and using Hurst exponent are two com-monly used methods. Based on the fractal geometry of earthquake time series, we point out that these two methods correlate to each other. In the perspective of fractional Brownian motion (FBM), an earthquake sequence with b>3/4 and that with b<3/4 have different dynamic properties. 展开更多
关键词 b HURST指数 地震预测 地震序列 分形几何 分数布郎运动
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2024年1月23日乌什M_(S)7.1地震序列b值随时间演化特征 被引量:1
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作者 翟娟 洪德全 +4 位作者 周康云 田雨桐 赵梦强 杨震 朱亮 《地震地磁观测与研究》 2024年第3期9-15,共7页
选取2024年1月23日乌什M_(S)7.1地震序列目录,利用最大似然法计算该地震序列b值大小,分析震中区b值随时间的演化特征,得到以下认识:①震中区b值在强余震前呈明显下降变化特征,但无法准确评估b值下降后强余震的发生次数;②b值能够反映研... 选取2024年1月23日乌什M_(S)7.1地震序列目录,利用最大似然法计算该地震序列b值大小,分析震中区b值随时间的演化特征,得到以下认识:①震中区b值在强余震前呈明显下降变化特征,但无法准确评估b值下降后强余震的发生次数;②b值能够反映研究区不同时间的应力水平,对强余震的预测具有一定指示意义。 展开更多
关键词 乌什M_(S)7.1地震序列 b 最大似然法 时间演化特征
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Continuous-cyclic variations in the b-value of the earthquake frequency-magnitude distribution 被引量:3
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作者 Z.H.El-Isa 《Earthquake Science》 2013年第5期301-320,共20页
Seismicity of the Earth (M ≥ 4.5) was compiled from NEIC, IRIS and ISC catalogues and used to compute b-value based on various time windows. It is found that continuous cyclic b-variations occur on both long and sh... Seismicity of the Earth (M ≥ 4.5) was compiled from NEIC, IRIS and ISC catalogues and used to compute b-value based on various time windows. It is found that continuous cyclic b-variations occur on both long and short time scales, the latter being of much higher value and sometimes in excess of 0.7 of the absolute b-value. These variations occur not only yearly or monthly, but also daily. Before the occurrence of large earthquakes, b-values start increasing with variable gradients that are affected by foreshocks. In some cases, the gradient is reduced to zero or to a negative value a few days before the earthquake occurrence. In general, calculated b-values attain maxima 1 day before large earthquakes and minima soon after their occurrence. Both linear regression and maximum likelihood methods give correlatable, but variable results. It is found that an expanding time window technique from a fixed starting point is more effective in the study of b-variations. The calculated b-variations for the whole Earth, its hemispheres, quadrants and the epicentral regions of some large earthquakes are of both local and regional character, which may indicate that in such cases, the geodynamic processes acting within a certain region have a much regional effect within the Earth. The b-variations have long been known to vary with a number of local and regional factors including tectonic stresses. The results reported here indicate that geotectonic stress remains the most significant factor that controls b-variations. It is found that for earthquakes with Mw ≥ 7, an increase of about 0.20 in the b-value implies a stress increase that will result in an earthquake with a magnitude one unit higher. 展开更多
关键词 Earthquake frequency-magnitude b-value Temporal b-variation Spatial b-variation
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Spatial Variations of b-Values in the Coastal Area of Guangdong 被引量:2
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作者 ZHOU Pengxiang XIA Shaohong +4 位作者 SUN Jinlong CAO Jinghe XU Huilong ZHAO Fang CHEN Chuanxu 《Journal of Ocean University of China》 SCIE CAS CSCD 2018年第1期177-185,共9页
We used earthquake catalogs recorded by Guangdong Seismological Network from 2008 to 2014 to resolve the spatial variations of b-values in the coastal area of Guangdong, particularly in three key research areas(Yangji... We used earthquake catalogs recorded by Guangdong Seismological Network from 2008 to 2014 to resolve the spatial variations of b-values in the coastal area of Guangdong, particularly in three key research areas(Yangjiang, Heyuan, and offshore Nanao Island) with strong seismicity. Our results revealed that b-values exhibited significant spatial variations, and zones with low b-values could indicate the most likely seismogenic area of large earthquakes. We observed three clear low b-value patches in the offshore Nanao Island. We found a distinct high b-value peak at the depth of 11 km and two minimum peaks at about 14 and 7–8 km in the Yangjiang area. The overall b-values generally decrease with depth in the Heyuan area. The spatial variations of b-values reflect tectonic anomalies; that is, the ‘low-high-low' distribution of b-values in the offshore Nanao Island and the Yangjiang area may indicate the anomaly of the crustal structure with a weak layer. The b-values of reservoir-induced seismicity are obviously lower than that induced by tectonism. This finding indicates that the reservoir area is generally at high stress state under the condition of high pore pressure. We inferred that large earthquakes might be prone to occur at 10–12 km depth in the offshore Nanao Island, at 12–15 km depth in the Yangjiang area, and at the lower part of the seismic activity zone in the Heyuan area. Moreover, the upstream area of the Xinfengjiang reservoir is the most likely area of future large earthquakes in the Heyuan area. 展开更多
关键词 b-valueS EARTHQUAKE GUANGDONG SEISMOGENIC area STRESS
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Atomic Decompositions of Weak Hardy Spaces of B-Valued Martingales 被引量:4
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作者 MA Tao LIU Peide 《Wuhan University Journal of Natural Sciences》 EI CAS 2006年第3期456-460,共5页
The atomic decompositions of weak Hardy spaces of Banach-space-valued martingales are given. With the help of the atomic decompositions, some inequalities for B-valued martingales are established in the case 0〈r≤1. ... The atomic decompositions of weak Hardy spaces of Banach-space-valued martingales are given. With the help of the atomic decompositions, some inequalities for B-valued martingales are established in the case 0〈r≤1. Here the results are connected closely with the p-uniform smoothness and q-uniform convexity of Banach spaces which the martingales take values in. 展开更多
关键词 atomic decomposition weak Hardy space b-valued martingale
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Fibrotouch联合血清标志物评估慢性乙型肝炎肝纤维化的价值
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作者 杨兆辉 陈珑斌 马龙 《中国卫生标准管理》 2024年第14期14-18,共5页
目的分析瞬时弹性成像技术(Fibrotouch)评估联合血清标志物在慢性乙型肝炎肝纤维化程度评估中的价值。方法选择厦门市第三医院2019年3月—2021年9月收治的180例慢性乙型肝炎患者作为研究对象。依病理结果分为无纤维化组72例、早期纤维化... 目的分析瞬时弹性成像技术(Fibrotouch)评估联合血清标志物在慢性乙型肝炎肝纤维化程度评估中的价值。方法选择厦门市第三医院2019年3月—2021年9月收治的180例慢性乙型肝炎患者作为研究对象。依病理结果分为无纤维化组72例、早期纤维化组68例和进展性纤维化组40例。所有患者均接受Fibrotouch检测肝脏硬度值(liver stiffness measurement,LSM)、血清透明质酸(hyaluronic acid,HA)、黏连蛋白(laminin,LN)、Ⅳ型胶原(collage typeⅣ,CⅣ)和Ⅲ型前胶原(precollagen typeⅢ,PCⅢ)水平。Spearman相关性分析LSM、HA、LN、CⅣ、PCⅢ水平与肝纤维化程度的相关性。受试者工作特征(receiver operating characteristic,ROC)曲线分析上述指标联合检测诊断肝纤维化的价值。结果不同肝纤维程度患者LSM、HA、LN、CⅣ、PCⅢ比较,差异有统计学意义(P<0.05);且进展性纤维化组各指标均高于早期纤维化组、无纤维化组,早期纤维化组各指标均高于无纤维化组(P<0.05);LSM、HA、LN、CⅣ、PCⅢ均与肝纤维化程度呈正相关,相关系数分别为0.949、0.912、0.898、0.867、0.893(P<0.05);ROC曲线分析显示,LSM、HA、LN、CⅣ、PCⅢ、联合检测肝纤维化曲线下面积(area under curve,AUC)分别为0.790、0.839、0.623、0.863、0.804、0.968,联合检测预测效果最好,且联合检测敏感度高于其他各项单独检测指标(P<0.05)。结论慢性乙型肝炎患者LSM、HA、LN、CⅣ、PCⅢ均与肝纤维化程度呈正相关,上述指标联合检查效果最好,敏感度最高,临床可联合检测上述指标诊断肝纤维化。 展开更多
关键词 瞬时弹性成像技术评估 血清标志物 慢性乙型肝炎 肝纤维化程度 肝脏硬度值 价值评估
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