Rapid drawdown is a critical design condition for the upstream or riverside slope of earth dams and levees. A new total stress rapid drawdown method based on finite element analysis is used to analyze the rapid drawdo...Rapid drawdown is a critical design condition for the upstream or riverside slope of earth dams and levees. A new total stress rapid drawdown method based on finite element analysis is used to analyze the rapid drawdown failure that occurred at Pilarcitos Dam in 1969. Effective consolidation stresses in the slope prior to drawdown are determined using linear elastic finite element analysis. Undrained strengths from isotropically consolidated undrained （ICU） triaxial compression tests are related directly to the calculated consolidation stresses and assigned to the elements in the model by interpolation. Two different interpretations of the undrained strength envelope are examined. Strength reduction finite element analyses are used to evaluate stability of the dam. Back analysis suggests that undrained strengths from ICU tests must be reduced by 30% for use with this rapid drawdown method. The failure mechanism predicted for Pilarcitos Dam is sensitive to the relationship between undrained strength and consolidation stress.展开更多
为探讨菊茎叶总黄酮(total flavonoids from stems and leaves of Chrysanthemum morifolium,TFCSL)抗氧化应激的活性成分,阐明其药效物质基础和作用机制。采用HPLC建立不同批次TFCSL指纹图谱;以高浓度葡萄糖诱导人脐静脉内皮细胞建立...为探讨菊茎叶总黄酮(total flavonoids from stems and leaves of Chrysanthemum morifolium,TFCSL)抗氧化应激的活性成分,阐明其药效物质基础和作用机制。采用HPLC建立不同批次TFCSL指纹图谱;以高浓度葡萄糖诱导人脐静脉内皮细胞建立氧化损伤模型,将丙二醛含量、乳酸脱氢酶含量和超氧化物歧化酶活性作为药效指标;采用灰色关联度和偏最小二乘法分析其谱-效关系确定抗氧化药效物质基础;基于网络药理学结合分子对接探究核心靶点及作用通路。从12批次TFCSL指纹图谱中确定12个共有峰,指认其中9个化学成分;各批次总黄酮样品均可减少细胞凋亡、降低丙二醛及乳酸脱氢酶含量、提高超氧化物歧化酶活性;综合2种数学模型确定峰5(芹菜素-7-O-β-D-葡萄糖苷)、峰6(异绿原酸C)、峰7(香叶木素-7-O-β-D-葡萄糖苷)为抗氧化物质基础;筛选出的3个活性成分作用于抗氧化应激的33个靶点;关键靶点为TNF、CASP3、EDNRA、XDH、PTGS2、MMP2,主要涉及脂质和动脉粥样硬化信号通路、IL-17信号通路、糖尿病并发症AGE-RAGE信号通路、TNF通路、MPKA通路等信号通路;分子对接结果显示活性成分与关键靶点之间均有较好的结合力。表明TFCSL抗氧化应激的物质基础可能为芹菜素-7-O-β-D-葡萄糖苷、异绿原酸C、香叶木素-7-O-β-D-葡萄糖苷,推测通过TNF、CASP3等靶点作用动脉粥样硬化信号通路、IL17信号通路发挥作用,体现菊茎叶多成分、多靶点抗氧化的作用特点。展开更多
Cemented paste backfill(CPB) is largely used in underground mines worldwide.A key issue associated with application of CPB is to estimate the stresses in backfilled stopes and on barricades.Recent numerical and experi...Cemented paste backfill(CPB) is largely used in underground mines worldwide.A key issue associated with application of CPB is to estimate the stresses in backfilled stopes and on barricades.Recent numerical and experimental results show that arching effect is absent shortly after the placement of CPB in stopes.However,stress decreases in barricade drift with increasing distance between the measurement points and drawpoint have also been observed,demonstrating arching effect shortly after the pouring of CPB.To explain these paradoxes,CPB is considered as Bingham fluid having a yield shear stress.Three dimensional analytical solutions are proposed to evaluate the short-term total stresses in backfilled stopes and on barricades,accounting for the CPB's yield shear stress-induced arching effect.Stress diminution due to such arching effect in the backfilled stopes and on barricades is indeed obtained.But the reduction becomes insignificant using typical yield shear stress and stope geometry.More analyses indicate that the typical yield shear stress values do not fully correspond to field conditions where the yield shear stress would increase exponentially due to apparent consolidation(loss of water by drainage,a phenomenon similar to the desiccation of overly saturated fine-grained materials).展开更多
目的探讨隐神经联合膝关节囊后阻滞对全膝关节置换患者术后应激反应、镇痛效应及关节功能恢复的影响。方法纳入2021年1月至2022年1月我院择期行全膝关节置换术的98例患者,按照随机数字表法分为观察组(采用隐神经联合膝关节囊后阻滞)和...目的探讨隐神经联合膝关节囊后阻滞对全膝关节置换患者术后应激反应、镇痛效应及关节功能恢复的影响。方法纳入2021年1月至2022年1月我院择期行全膝关节置换术的98例患者,按照随机数字表法分为观察组(采用隐神经联合膝关节囊后阻滞)和对照组(采用单纯隐神经阻滞),每组49例。比较术后6 h、12 h、24 h 2组患者静息和动态疼痛视觉模拟量表(VAS)评分;比较术前、术后3 d、术后5 d、术后7 d 2组患者膝关节活动度;比较术前、术后4 h、术后12 h、术后24 h、术后48 h 2组患者应激指标[皮质醇(Cor)、促肾上腺皮质激(ACTH)]及疼痛介质指标[降钙素基因相关肽(CGRP)、β-内啡肽(β-EP)、6-酮前列腺素E1α(6-keto-PGE1α)、P物质(SP)];记录2组患者治疗期间不良反应发生情况。结果2组患者不同时间点静息和动态VAS评分在时间因素、组间因素和时间与组间交互作用方面比较,差异具有统计学意义(P<0.05);2组患者不同时间点膝关节活动度在时间因素、组间因素和时间与组间交互作用方面比较,差异具有统计学意义(P<0.05);2组患者不同时间点Cor、ACTH含量在时间因素、组间因素和时间与组间交互作用方面比较,差异具有统计学意义(P<0.05);2组患者不同时间点β-EP、SP、CGRP、6-keto-PGE1α含量在时间因素、组间因素和时间与组间交互作用方面比较,差异具有统计学意义(P<0.05);2组患者不良反应发生率比较,差异无统计学意义(P>0.05)。结论全膝关节置换术中采用隐神经联合膝关节囊后阻滞,可减少患者应激反应,提升术后镇痛效应,改善早期运动功能,安全性高。展开更多
文摘Rapid drawdown is a critical design condition for the upstream or riverside slope of earth dams and levees. A new total stress rapid drawdown method based on finite element analysis is used to analyze the rapid drawdown failure that occurred at Pilarcitos Dam in 1969. Effective consolidation stresses in the slope prior to drawdown are determined using linear elastic finite element analysis. Undrained strengths from isotropically consolidated undrained （ICU） triaxial compression tests are related directly to the calculated consolidation stresses and assigned to the elements in the model by interpolation. Two different interpretations of the undrained strength envelope are examined. Strength reduction finite element analyses are used to evaluate stability of the dam. Back analysis suggests that undrained strengths from ICU tests must be reduced by 30% for use with this rapid drawdown method. The failure mechanism predicted for Pilarcitos Dam is sensitive to the relationship between undrained strength and consolidation stress.
文摘为探讨菊茎叶总黄酮(total flavonoids from stems and leaves of Chrysanthemum morifolium,TFCSL)抗氧化应激的活性成分,阐明其药效物质基础和作用机制。采用HPLC建立不同批次TFCSL指纹图谱;以高浓度葡萄糖诱导人脐静脉内皮细胞建立氧化损伤模型,将丙二醛含量、乳酸脱氢酶含量和超氧化物歧化酶活性作为药效指标;采用灰色关联度和偏最小二乘法分析其谱-效关系确定抗氧化药效物质基础;基于网络药理学结合分子对接探究核心靶点及作用通路。从12批次TFCSL指纹图谱中确定12个共有峰,指认其中9个化学成分;各批次总黄酮样品均可减少细胞凋亡、降低丙二醛及乳酸脱氢酶含量、提高超氧化物歧化酶活性;综合2种数学模型确定峰5(芹菜素-7-O-β-D-葡萄糖苷)、峰6(异绿原酸C)、峰7(香叶木素-7-O-β-D-葡萄糖苷)为抗氧化物质基础;筛选出的3个活性成分作用于抗氧化应激的33个靶点;关键靶点为TNF、CASP3、EDNRA、XDH、PTGS2、MMP2,主要涉及脂质和动脉粥样硬化信号通路、IL-17信号通路、糖尿病并发症AGE-RAGE信号通路、TNF通路、MPKA通路等信号通路;分子对接结果显示活性成分与关键靶点之间均有较好的结合力。表明TFCSL抗氧化应激的物质基础可能为芹菜素-7-O-β-D-葡萄糖苷、异绿原酸C、香叶木素-7-O-β-D-葡萄糖苷,推测通过TNF、CASP3等靶点作用动脉粥样硬化信号通路、IL17信号通路发挥作用,体现菊茎叶多成分、多靶点抗氧化的作用特点。
基金the Natural Sciences and Engineering Research Council of Canada(NSERC)Institut de recherche Robert-Sauve en sante et en securite du travail(IRSST)industrial partners of the Research Institute on Mines and the Environment(RIME UQAT-Polytechnique)
文摘Cemented paste backfill(CPB) is largely used in underground mines worldwide.A key issue associated with application of CPB is to estimate the stresses in backfilled stopes and on barricades.Recent numerical and experimental results show that arching effect is absent shortly after the placement of CPB in stopes.However,stress decreases in barricade drift with increasing distance between the measurement points and drawpoint have also been observed,demonstrating arching effect shortly after the pouring of CPB.To explain these paradoxes,CPB is considered as Bingham fluid having a yield shear stress.Three dimensional analytical solutions are proposed to evaluate the short-term total stresses in backfilled stopes and on barricades,accounting for the CPB's yield shear stress-induced arching effect.Stress diminution due to such arching effect in the backfilled stopes and on barricades is indeed obtained.But the reduction becomes insignificant using typical yield shear stress and stope geometry.More analyses indicate that the typical yield shear stress values do not fully correspond to field conditions where the yield shear stress would increase exponentially due to apparent consolidation(loss of water by drainage,a phenomenon similar to the desiccation of overly saturated fine-grained materials).
文摘目的探讨隐神经联合膝关节囊后阻滞对全膝关节置换患者术后应激反应、镇痛效应及关节功能恢复的影响。方法纳入2021年1月至2022年1月我院择期行全膝关节置换术的98例患者,按照随机数字表法分为观察组(采用隐神经联合膝关节囊后阻滞)和对照组(采用单纯隐神经阻滞),每组49例。比较术后6 h、12 h、24 h 2组患者静息和动态疼痛视觉模拟量表(VAS)评分;比较术前、术后3 d、术后5 d、术后7 d 2组患者膝关节活动度;比较术前、术后4 h、术后12 h、术后24 h、术后48 h 2组患者应激指标[皮质醇(Cor)、促肾上腺皮质激(ACTH)]及疼痛介质指标[降钙素基因相关肽(CGRP)、β-内啡肽(β-EP)、6-酮前列腺素E1α(6-keto-PGE1α)、P物质(SP)];记录2组患者治疗期间不良反应发生情况。结果2组患者不同时间点静息和动态VAS评分在时间因素、组间因素和时间与组间交互作用方面比较,差异具有统计学意义(P<0.05);2组患者不同时间点膝关节活动度在时间因素、组间因素和时间与组间交互作用方面比较,差异具有统计学意义(P<0.05);2组患者不同时间点Cor、ACTH含量在时间因素、组间因素和时间与组间交互作用方面比较,差异具有统计学意义(P<0.05);2组患者不同时间点β-EP、SP、CGRP、6-keto-PGE1α含量在时间因素、组间因素和时间与组间交互作用方面比较,差异具有统计学意义(P<0.05);2组患者不良反应发生率比较,差异无统计学意义(P>0.05)。结论全膝关节置换术中采用隐神经联合膝关节囊后阻滞,可减少患者应激反应,提升术后镇痛效应,改善早期运动功能,安全性高。
