To promote the production and application of artificial aggregates,save natural sand resources and protect the ecological environment,we evaluated the feasibility of using spherical porous functional aggregates(SPFAs)...To promote the production and application of artificial aggregates,save natural sand resources and protect the ecological environment,we evaluated the feasibility of using spherical porous functional aggregates(SPFAs) formed by basalt saw mud under autoclave curing in ordinary structural concrete.In our work,two types of prewetted functional aggregates were taken as replacements for natural aggregates with different volume substitution rates(0%,5%,10%,15%,20%,25%,and 30%) in the preparation of ordinary structural concrete with water-to-binder ratios(W/B) of 0.48 and 0.33.The effects of the functional aggregate properties and content,W/B,and curing age on the fluidity,density,mechanical properties and autogenous shrinkage of ordinary concrete were analyzed.The experimental results showed that the density of concrete declined at a rate of not more than 5%,and the 28 d compressive strength could reach 31.0-68.2 MPa.Low W/B,long curing age and high-quality functional aggregates were conducive to enhancing the mechanical properties of SPFAs concrete.Through the rolling effects,SPFAs can optimize the particle gradation of aggregate systems and improve the fluidity of concrete,and the water stored inside SPFAs provides an internal curing effect,which prolongs the cement hydration process and considerably reduces the autogenous shrinkage of concrete.SPFAs exhibits high strength and high density,as well as being more cost-effective and ecological,and is expected to be widely employed in ordinary structural concrete.展开更多
背景口服中药在慢性阻塞性肺疾病急性加重(AECOPD)的治疗中应用广泛,但相关临床试验的结局指标尚未得到统一和规范。目的通过筛选已发表的以口服中药为AECOPD治疗措施的随机对照试验(RCT),总结其文献特征和选用的结局指标情况,为中医药...背景口服中药在慢性阻塞性肺疾病急性加重(AECOPD)的治疗中应用广泛,但相关临床试验的结局指标尚未得到统一和规范。目的通过筛选已发表的以口服中药为AECOPD治疗措施的随机对照试验(RCT),总结其文献特征和选用的结局指标情况,为中医药治疗AECOPD临床试验设计和结局指标选择提供参考。方法计算机检索中国知网、万方数据知识服务平台、维普网、中国生物医学文献数据库、PubMed、Embase、Web of Science、Cochrane Library、ClinicalTrials.gov、中国临床试验注册中心,获取口服中药治疗AECOPD的RCT和临床试验注册方案,检索时限为2018年1月—2022年10月。由2位评价员独立筛选文献、提取资料后,采用定性分析的方法,对纳入研究的结局指标选择情况进行描述。结果纳入578篇文献,包含574篇已报告试验结果的RCT及4个临床试验注册方案。574篇RCT共纳入51508例患者。88篇文献在纳入标准中限定了患者的疾病分级,361篇文献在纳入标准中限定了中医证型,6篇文献报告了盲法,6篇文献提及了随访。纳入文献共涉及4030个结局指标,单篇文献结局指标数量范围为1~24个。按照结局指标的功能属性,将其归为8个指标域:中医症状/证候、症状/体征、理化检测、生活质量、远期预后、经济学评估、安全性评价、其他,报告率最高的指标域是理化检测,报告频次排名前5位的结局指标项目是:有效率(11.5%)、第1秒用力呼气容积(7.5%)、中医症状/证候评分(7.0%)、第1秒用力呼气容积/用力肺活量(6.8%)、用力肺活量(4.6%)。445篇文献报告了有效率的组成,报告率排名前5位的研究指标依次为症状(423篇)、体征(281篇)、中医证候评分(203篇)、实验室检查(89篇)、肺功能(71篇)。结论口服中药治疗AECOPD的RCT涉及的结局指标数量多、范围广,纳入的文献在不同程度上关注了口服中药对AECOPD患者的症状体征、理化检测指标、生活质量、远期预后、经济学评价和安全性结局等方面的影响。但结局指标的选择仍存在多方面的问题:结局指标主次不清;主要关注替代终点,对临床终点的关注不足;对卫生经济学指标关注不足;有效性参考来源不一、判断标准不一。研究者可参考已发表的核心指标集,合理设计结局指标,以提高中医药临床研究的质量。展开更多
基金Funded by the National Natural Science Foundation of China(No.52378213)the Technology Development Project(No.20201902977180010) of CABR Technology Co.,Ltd。
文摘To promote the production and application of artificial aggregates,save natural sand resources and protect the ecological environment,we evaluated the feasibility of using spherical porous functional aggregates(SPFAs) formed by basalt saw mud under autoclave curing in ordinary structural concrete.In our work,two types of prewetted functional aggregates were taken as replacements for natural aggregates with different volume substitution rates(0%,5%,10%,15%,20%,25%,and 30%) in the preparation of ordinary structural concrete with water-to-binder ratios(W/B) of 0.48 and 0.33.The effects of the functional aggregate properties and content,W/B,and curing age on the fluidity,density,mechanical properties and autogenous shrinkage of ordinary concrete were analyzed.The experimental results showed that the density of concrete declined at a rate of not more than 5%,and the 28 d compressive strength could reach 31.0-68.2 MPa.Low W/B,long curing age and high-quality functional aggregates were conducive to enhancing the mechanical properties of SPFAs concrete.Through the rolling effects,SPFAs can optimize the particle gradation of aggregate systems and improve the fluidity of concrete,and the water stored inside SPFAs provides an internal curing effect,which prolongs the cement hydration process and considerably reduces the autogenous shrinkage of concrete.SPFAs exhibits high strength and high density,as well as being more cost-effective and ecological,and is expected to be widely employed in ordinary structural concrete.
文摘背景口服中药在慢性阻塞性肺疾病急性加重(AECOPD)的治疗中应用广泛,但相关临床试验的结局指标尚未得到统一和规范。目的通过筛选已发表的以口服中药为AECOPD治疗措施的随机对照试验(RCT),总结其文献特征和选用的结局指标情况,为中医药治疗AECOPD临床试验设计和结局指标选择提供参考。方法计算机检索中国知网、万方数据知识服务平台、维普网、中国生物医学文献数据库、PubMed、Embase、Web of Science、Cochrane Library、ClinicalTrials.gov、中国临床试验注册中心,获取口服中药治疗AECOPD的RCT和临床试验注册方案,检索时限为2018年1月—2022年10月。由2位评价员独立筛选文献、提取资料后,采用定性分析的方法,对纳入研究的结局指标选择情况进行描述。结果纳入578篇文献,包含574篇已报告试验结果的RCT及4个临床试验注册方案。574篇RCT共纳入51508例患者。88篇文献在纳入标准中限定了患者的疾病分级,361篇文献在纳入标准中限定了中医证型,6篇文献报告了盲法,6篇文献提及了随访。纳入文献共涉及4030个结局指标,单篇文献结局指标数量范围为1~24个。按照结局指标的功能属性,将其归为8个指标域:中医症状/证候、症状/体征、理化检测、生活质量、远期预后、经济学评估、安全性评价、其他,报告率最高的指标域是理化检测,报告频次排名前5位的结局指标项目是:有效率(11.5%)、第1秒用力呼气容积(7.5%)、中医症状/证候评分(7.0%)、第1秒用力呼气容积/用力肺活量(6.8%)、用力肺活量(4.6%)。445篇文献报告了有效率的组成,报告率排名前5位的研究指标依次为症状(423篇)、体征(281篇)、中医证候评分(203篇)、实验室检查(89篇)、肺功能(71篇)。结论口服中药治疗AECOPD的RCT涉及的结局指标数量多、范围广,纳入的文献在不同程度上关注了口服中药对AECOPD患者的症状体征、理化检测指标、生活质量、远期预后、经济学评价和安全性结局等方面的影响。但结局指标的选择仍存在多方面的问题:结局指标主次不清;主要关注替代终点,对临床终点的关注不足;对卫生经济学指标关注不足;有效性参考来源不一、判断标准不一。研究者可参考已发表的核心指标集,合理设计结局指标,以提高中医药临床研究的质量。
