An exquisite mesostructure model was presented to predict the effective elastic modulus of concrete,in which concrete is realized as a four-phase composite material consisting of coarse aggregates,mortar matrix,interf...An exquisite mesostructure model was presented to predict the effective elastic modulus of concrete,in which concrete is realized as a four-phase composite material consisting of coarse aggregates,mortar matrix,interfacial transition zone(ITZ),and initial defects.With the three-dimensional(3D)finite element(FE)simulation,the highly heterogeneous composite elastic behavior of concrete was modeled,and the predicted results were compared with theoretical estimations for validation.Monte Carlo(MC)simulations were performed with the proposed mesostructure model to investigate the various factors of initial defects influencing the elastic modulus of concrete,such as the shape and concentration(pore volume fraction or crack density)of microspores and microcracks.It is found that the effective elastic modulus of concrete decreases with the increase of initial defects concentration,while the distribution and shape characteristics also exert certain influences due to the stress concentration caused by irregular inclusion shape.展开更多
目的:对稳心颗粒治疗心房颤动(房颤)的有效性及安全性进行全面系统的评价。方法:电子检索PubMed、Web of Science、Cochrane Library等外文数据库及中国知识基础设施工程(CNKI)、万方数据知识服务平台(Wan Fang Data)、维普期刊资源整...目的:对稳心颗粒治疗心房颤动(房颤)的有效性及安全性进行全面系统的评价。方法:电子检索PubMed、Web of Science、Cochrane Library等外文数据库及中国知识基础设施工程(CNKI)、万方数据知识服务平台(Wan Fang Data)、维普期刊资源整合服务平台(VIP)、中国生物医学文献服务系统(SinoMed)等中文数据库,时间截至2018年10月1日。按照Cochrane手册推荐的质量评价标准对纳入研究进行质量学评价,采用Rev Man 5.3软件进行数据分析,采用Stata 14软件Begg检验进行发表偏倚分析。结果:共纳入24篇随机对照试验(RCTs),涉及到2246名房颤患者。结果显示,稳心颗粒单用或者联合西药治疗在控制快速心室率(MD=-7.14,95%CI:-8.42--5.87),降低房颤发作次数和持续时间,缩短窦律转复时间(MD=-3.04,95%CI:-3.47--2.61),增加窦律转复率(RR=1.19,95%CI:1.09-1.29),减少房颤复发率(RR=0.28,95%CI:0.13-0.59),提高左室射血分数(LVEF)(MD=3.44,95%CI:0.87-6.01),改善左心室舒张末内径(LVEDD)(MD=-2.47,95%CI:-2.86--2.08),降低左心房内径(LAd)(MD=-0.91,95%CI:-1.58--0.25),减少P波离散度(Pd)(MD=-4.04,95%CI:-4.15--3.93)等方面效果优于空白对照、安慰剂或单用西药治疗。稳心颗粒联合小剂量胺碘酮在改善P波最大时限(Pmax)优于单用常规剂量胺碘酮治疗(MD=-8.25,95%CI:-10.33--6.17),而稳心颗粒联合常规剂量胺碘酮治疗效果更优(MD=-13.10,95%CI:-13.65--12.55)。与对照组相比,联合治疗组不良反应发生更少,且Begg检验未发现发表偏倚。结论:稳心颗粒单用或者联合西药在房颤治疗中有良好疗效,但仍需要高质量证据予以验证。展开更多
基金Founded by the National Natural Science Foundation of China(No.42002287)the Fundamental Research Funds for the Central Universities,China University of Geosciences(Wuhan)(No.CUG2106335)。
文摘An exquisite mesostructure model was presented to predict the effective elastic modulus of concrete,in which concrete is realized as a four-phase composite material consisting of coarse aggregates,mortar matrix,interfacial transition zone(ITZ),and initial defects.With the three-dimensional(3D)finite element(FE)simulation,the highly heterogeneous composite elastic behavior of concrete was modeled,and the predicted results were compared with theoretical estimations for validation.Monte Carlo(MC)simulations were performed with the proposed mesostructure model to investigate the various factors of initial defects influencing the elastic modulus of concrete,such as the shape and concentration(pore volume fraction or crack density)of microspores and microcracks.It is found that the effective elastic modulus of concrete decreases with the increase of initial defects concentration,while the distribution and shape characteristics also exert certain influences due to the stress concentration caused by irregular inclusion shape.
文摘目的:对稳心颗粒治疗心房颤动(房颤)的有效性及安全性进行全面系统的评价。方法:电子检索PubMed、Web of Science、Cochrane Library等外文数据库及中国知识基础设施工程(CNKI)、万方数据知识服务平台(Wan Fang Data)、维普期刊资源整合服务平台(VIP)、中国生物医学文献服务系统(SinoMed)等中文数据库,时间截至2018年10月1日。按照Cochrane手册推荐的质量评价标准对纳入研究进行质量学评价,采用Rev Man 5.3软件进行数据分析,采用Stata 14软件Begg检验进行发表偏倚分析。结果:共纳入24篇随机对照试验(RCTs),涉及到2246名房颤患者。结果显示,稳心颗粒单用或者联合西药治疗在控制快速心室率(MD=-7.14,95%CI:-8.42--5.87),降低房颤发作次数和持续时间,缩短窦律转复时间(MD=-3.04,95%CI:-3.47--2.61),增加窦律转复率(RR=1.19,95%CI:1.09-1.29),减少房颤复发率(RR=0.28,95%CI:0.13-0.59),提高左室射血分数(LVEF)(MD=3.44,95%CI:0.87-6.01),改善左心室舒张末内径(LVEDD)(MD=-2.47,95%CI:-2.86--2.08),降低左心房内径(LAd)(MD=-0.91,95%CI:-1.58--0.25),减少P波离散度(Pd)(MD=-4.04,95%CI:-4.15--3.93)等方面效果优于空白对照、安慰剂或单用西药治疗。稳心颗粒联合小剂量胺碘酮在改善P波最大时限(Pmax)优于单用常规剂量胺碘酮治疗(MD=-8.25,95%CI:-10.33--6.17),而稳心颗粒联合常规剂量胺碘酮治疗效果更优(MD=-13.10,95%CI:-13.65--12.55)。与对照组相比,联合治疗组不良反应发生更少,且Begg检验未发现发表偏倚。结论:稳心颗粒单用或者联合西药在房颤治疗中有良好疗效,但仍需要高质量证据予以验证。
