目的评价掺铒钇铝石榴石(Er:YAG)激光光子引导的光声流(PIPS)效应在根管荡洗中的作用效果。方法计算机检索中国知网、万方数据知识服务平台、维普中文科技期刊数据库、PubMed、Embase、Cochrane Library、Web of Science、SCOPUS数据库...目的评价掺铒钇铝石榴石(Er:YAG)激光光子引导的光声流(PIPS)效应在根管荡洗中的作用效果。方法计算机检索中国知网、万方数据知识服务平台、维普中文科技期刊数据库、PubMed、Embase、Cochrane Library、Web of Science、SCOPUS数据库,纳入有关PIPS根管荡洗作用的随机对照试验,检索时间从2010年1月至2020年7月,所选文献按照纳入和排除标准进行筛选,根据Cochrane系统评价的方法进行风险评估,根据《系统综述和荟萃分析优先报告的条目:PRISMA声明》确定的项目进行评价。结果最终共纳入45篇文章,通过归类描述和系统评价,这些文章体现了PIPS技术在灭菌、去除玷污层及牙本质碎屑、去除根管内氢氧化钙、增加牙本质小管渗透性等方面有显著的成效,但是仍有部分实验结果未能体现PIPS技术的优势。目前,PIPS技术的研究中存在实验对象(离体牙根管长度和弯曲度的差异)以及实验过程和方法未标准化、研究方法存在差异等问题,缺少根管微裂、根尖溢出冲洗液和碎屑、标准参数、不同根管荡洗方法作用效果的比较、随机对照的临床试验等方面的相关研究。结论大多数实验结果表明PIPS在灭菌、去除玷污层及牙本质碎屑、去除根管内氢氧化钙、增加牙本质小管渗透性等方面有显著的成效,但仍有实验结果存在争议,需要更多长期、大样本、高质量、设计严谨的实验来验证这些结论。展开更多
Photocatalytic splitting of water over p-type semiconductors is a promising strategy for production of hydrogen.However,the determination of rate law is rarely reported.To this purpose,copper oxide(CuO)is selected as ...Photocatalytic splitting of water over p-type semiconductors is a promising strategy for production of hydrogen.However,the determination of rate law is rarely reported.To this purpose,copper oxide(CuO)is selected as a model photocathode in this study,and the photogenerated surface charge density,interfacial charge transfer rate constant and their relation to the water reduction rate(in terms of photocurrent)were investigated by a combination of(photo)electrochemical techniques.The results showed that the charge transfer rate constant is exponential-dependent on the surface charge density,and that the photocurrent equals to the product of the charge transfer rate constant and surface charge density.The reaction is first-order in terms of surface charge density.Such an unconventional rate law contrasts with the reports in literature.The charge density-dependent rate constant results from the Fermi level pinning(i.e.,Galvani potential is the main driving force for the reaction)due to accumulation of charge in the surface states and/or Frumkin behavior(i.e.,chemical potential is the main driving force).This study,therefore,may be helpful for further investigation on the mechanism of hydrogen evolution over a CuO photocathode and for designing more efficient CuO-based photocatalysts.展开更多
文摘目的评价掺铒钇铝石榴石(Er:YAG)激光光子引导的光声流(PIPS)效应在根管荡洗中的作用效果。方法计算机检索中国知网、万方数据知识服务平台、维普中文科技期刊数据库、PubMed、Embase、Cochrane Library、Web of Science、SCOPUS数据库,纳入有关PIPS根管荡洗作用的随机对照试验,检索时间从2010年1月至2020年7月,所选文献按照纳入和排除标准进行筛选,根据Cochrane系统评价的方法进行风险评估,根据《系统综述和荟萃分析优先报告的条目:PRISMA声明》确定的项目进行评价。结果最终共纳入45篇文章,通过归类描述和系统评价,这些文章体现了PIPS技术在灭菌、去除玷污层及牙本质碎屑、去除根管内氢氧化钙、增加牙本质小管渗透性等方面有显著的成效,但是仍有部分实验结果未能体现PIPS技术的优势。目前,PIPS技术的研究中存在实验对象(离体牙根管长度和弯曲度的差异)以及实验过程和方法未标准化、研究方法存在差异等问题,缺少根管微裂、根尖溢出冲洗液和碎屑、标准参数、不同根管荡洗方法作用效果的比较、随机对照的临床试验等方面的相关研究。结论大多数实验结果表明PIPS在灭菌、去除玷污层及牙本质碎屑、去除根管内氢氧化钙、增加牙本质小管渗透性等方面有显著的成效,但仍有实验结果存在争议,需要更多长期、大样本、高质量、设计严谨的实验来验证这些结论。
基金the National Basic Research Development of China(2011CB936003)the National Natural Science Foundation of China(50971116)。
文摘Photocatalytic splitting of water over p-type semiconductors is a promising strategy for production of hydrogen.However,the determination of rate law is rarely reported.To this purpose,copper oxide(CuO)is selected as a model photocathode in this study,and the photogenerated surface charge density,interfacial charge transfer rate constant and their relation to the water reduction rate(in terms of photocurrent)were investigated by a combination of(photo)electrochemical techniques.The results showed that the charge transfer rate constant is exponential-dependent on the surface charge density,and that the photocurrent equals to the product of the charge transfer rate constant and surface charge density.The reaction is first-order in terms of surface charge density.Such an unconventional rate law contrasts with the reports in literature.The charge density-dependent rate constant results from the Fermi level pinning(i.e.,Galvani potential is the main driving force for the reaction)due to accumulation of charge in the surface states and/or Frumkin behavior(i.e.,chemical potential is the main driving force).This study,therefore,may be helpful for further investigation on the mechanism of hydrogen evolution over a CuO photocathode and for designing more efficient CuO-based photocatalysts.
