目的遴选并获取ICU机械通气患者误吸管理及预防的相关证据,并对最佳证据进行总结。方法使用计算机检索BMJ Best Practice、Up To Date、Joanna Briggs Institute循证卫生保健中心数据库、国际指南图书馆、美国指南网、英国国家临床医学...目的遴选并获取ICU机械通气患者误吸管理及预防的相关证据,并对最佳证据进行总结。方法使用计算机检索BMJ Best Practice、Up To Date、Joanna Briggs Institute循证卫生保健中心数据库、国际指南图书馆、美国指南网、英国国家临床医学研究所指南库、中国指南网、Cochrane Library、Pub Med、荷兰医学文摘数据库、护理文献累积索引数据库、中国生物医学文献数据库关于成人危重症患者误吸管理及预防的所有证据,包括指南、证据总结、最佳临床实践信息册、推荐实践、系统评价及原始研究。由2名研究者对纳入的文献质量进行评价,并对符合质量标准的文献进行证据提取。结果共纳入证据13篇,包括指南4篇,临床决策2篇、证据总结1篇、专家共识1篇、系统评价3篇、1篇随机对照试验和1篇类实验,最终总结了14条最佳证据。结论建议临床应用证据时,需要评估所在医疗机构的临床环境/条件、医护人员应用证据的促进因素及阻碍因素、患者意愿等进行有针对性的证据选择。同时,由于最佳证据随着时间的推移不断更新,应用人员还需对证据进行持续更新,最终通过应用最佳证据,以科学的护理方法解决成人危重症患者误吸的问题,从而提升护理质量。展开更多
Selective laser melting(SLM) is an attractive rapid prototyping technology for the fabrication of metallic components with complex structure and high performance. Aluminum alloy, one of the most pervasive structural m...Selective laser melting(SLM) is an attractive rapid prototyping technology for the fabrication of metallic components with complex structure and high performance. Aluminum alloy, one of the most pervasive structural materials, is well known for high specific strength and good corrosion resistance. But the poor laser formability of aluminum alloy restricts its application. There are problems such as limited processable materials, immature process conditions and metallurgical defects on SLM processing aluminum alloys. Some efforts have been made to solve the above problems. This paper discusses the current research status both related to the scientific understanding and technology applications. The paper begins with a brief introduction of basic concepts of aluminum alloys and technology characterization of laser selective melting. In addition, solidification theory of SLM process and formation mechanism of metallurgical defects are discussed. Then, the current research status of microstructure, properties and heat treatment of SLM processing aluminum alloys is systematically reviewed respectively. Lastly, a future outlook is given at the end of this review paper.展开更多
The research and development status of casting magnesium alloys including the commercial casting alloys and the new types casting alloys are reviewed,with more attention to microstructure and mechanical properties of ...The research and development status of casting magnesium alloys including the commercial casting alloys and the new types casting alloys are reviewed,with more attention to microstructure and mechanical properties of modified-AZ91,AM60 and WE43 alloys with various additions,and new types of low cost casting alloys and high strength casting alloys.The modification and/or refinement of Mg2 Si phase in Mg-Al-Si based casting alloys by various additions are discussed and new purifying technologies for casting magnesium alloys are introduced to improve the performance.The modified AZ81 alloy with reduced impurities is found to have the tensile strength of 280 ± 6 MPa and elongation of 16% ± 0.7%.The fatigue strength of AZ91 D alloy could be obviously improved by addition of Ce and Nd.The Mg-16Gd-2Ag-0.3Zr alloy exhibits very high tensile and yield strengths（UTS：423 MPa and YS：328 MPa）;however,its elongation still needs to be improved.展开更多
Research on magnesium alloys continues to attract great attention,with more than 3000 papers on magnesium and magnesium alloys published and indexed in SCI in 2020 alone.The results of bibliometric analyses show that ...Research on magnesium alloys continues to attract great attention,with more than 3000 papers on magnesium and magnesium alloys published and indexed in SCI in 2020 alone.The results of bibliometric analyses show that microstructure control and mechanical properties of Mg alloys are continuously the main research focus,and the corrosion and protection of Mg alloys are still widely concerned.The emerging research hot spots are mainly on functional magnesium materials,such as Mg ion batteries,hydrogen storage Mg materials,and bio-magnesium alloys.Great contributions to the research and development of magnesium alloys in 2020 have been made by Chongqing University,Chinese Academy of Sciences,Central South University,Shanghai Jiaotong University,Northeastern University,Helmholtz Zentrum Geesthacht,etc.The directions for future research are suggested,including:1)the synergistic control of microstructures to achieve high-performance magnesium alloys with concurrent high strength and superior plasticity along with high corrosion resistance and low cost;2)further development of functional magnesium materials such as Mg batteries,hydrogen storage Mg materials,structural-functional materials and bio-magnesium materials;3)studies on the effective corrosion protection and control of degradation rate of magnesium alloys;4)further improvement of advanced processing technology on Mg alloys.展开更多
Defect formation is a common problem in selective laser melting （SLM）. This paper provides a review of defect formation mechanisms in SLM. It sum- marizes the recent research outcomes on defect findings and classifi...Defect formation is a common problem in selective laser melting （SLM）. This paper provides a review of defect formation mechanisms in SLM. It sum- marizes the recent research outcomes on defect findings and classification, analyzes formation mechanisms of the common defects, such as porosities, incomplete fusion holes, and cracks. The paper discusses the effect of the process parameters on defect formation and the impact of defect formation on the mechanical properties of a fabri- cated part. Based on the discussion, the paper proposes strategies for defect suppression and control in SLM.展开更多
There is an increasing interest in the development of magnesium alloys both for industrial and biomedical applications. Industrial interest in magnesium alloys is based on strong demand of weight reduction of transpor...There is an increasing interest in the development of magnesium alloys both for industrial and biomedical applications. Industrial interest in magnesium alloys is based on strong demand of weight reduction of transportation vehicles for better fuel efficiency, so higher strength, and better ductility and corrosion resistance are required. Nevertheless, biomedical magnesium alloys require appropriate mechanical properties, suitable degradation rate in physiological environment, and what is most important, biosafety to human body. Rather than simply apply commercial magnesium alloys to biomedical field, new alloys should be designed from the point of view of nutriology and toxicology. This article provides a review of state-of-the-art of magnesium alloy implants and devices for orthopedic, cardiovascular and tissue engineering applications. Advances in new alloy design, novel structure design and surface modification are overviewed. The factors that influence the corrosion behavior of magnesium alloys are discussed and the strategy in the future development of biomedical magnesium alloys is proposed.展开更多
文摘目的遴选并获取ICU机械通气患者误吸管理及预防的相关证据,并对最佳证据进行总结。方法使用计算机检索BMJ Best Practice、Up To Date、Joanna Briggs Institute循证卫生保健中心数据库、国际指南图书馆、美国指南网、英国国家临床医学研究所指南库、中国指南网、Cochrane Library、Pub Med、荷兰医学文摘数据库、护理文献累积索引数据库、中国生物医学文献数据库关于成人危重症患者误吸管理及预防的所有证据,包括指南、证据总结、最佳临床实践信息册、推荐实践、系统评价及原始研究。由2名研究者对纳入的文献质量进行评价,并对符合质量标准的文献进行证据提取。结果共纳入证据13篇,包括指南4篇,临床决策2篇、证据总结1篇、专家共识1篇、系统评价3篇、1篇随机对照试验和1篇类实验,最终总结了14条最佳证据。结论建议临床应用证据时,需要评估所在医疗机构的临床环境/条件、医护人员应用证据的促进因素及阻碍因素、患者意愿等进行有针对性的证据选择。同时,由于最佳证据随着时间的推移不断更新,应用人员还需对证据进行持续更新,最终通过应用最佳证据,以科学的护理方法解决成人危重症患者误吸的问题,从而提升护理质量。
基金sponsored by National Key Research and Development Program "Additive Manufacturing and Laser Manufacturing" (No. 2016YFB1100101)Natural and Science Foundation of China (Grant Nos. 51775208, 51505166)+4 种基金Hubei Science Fund for Distinguished Young Scholars (No. 0216110085)Wuhan Morning Light Plan of Youth Science and Technology (No. 0216110066)Graduates’ Innovation Fund, Huazhong University of Science and Technology (No. 5003110027)Fundamental Research Funds for the Central University (No. 2017JYCXJJ004)the Academic frontier youth team at Huazhong University of Science and Technology (HUST)
文摘Selective laser melting(SLM) is an attractive rapid prototyping technology for the fabrication of metallic components with complex structure and high performance. Aluminum alloy, one of the most pervasive structural materials, is well known for high specific strength and good corrosion resistance. But the poor laser formability of aluminum alloy restricts its application. There are problems such as limited processable materials, immature process conditions and metallurgical defects on SLM processing aluminum alloys. Some efforts have been made to solve the above problems. This paper discusses the current research status both related to the scientific understanding and technology applications. The paper begins with a brief introduction of basic concepts of aluminum alloys and technology characterization of laser selective melting. In addition, solidification theory of SLM process and formation mechanism of metallurgical defects are discussed. Then, the current research status of microstructure, properties and heat treatment of SLM processing aluminum alloys is systematically reviewed respectively. Lastly, a future outlook is given at the end of this review paper.
基金supported by the National Natural Science Foundation of China(Grant Nos.51531002,51474043 and 51571043)the Ministry of Education of China(SRFDR 20130191110018)+1 种基金Chongqing Municipal Government(CSTC2013JCYJC60001,CEC project,Two River Scholar Project and The Chief Scientist Studio Project)Fundamental Research Funds for the Central Universities(No.106112015CDJZR135515)
文摘The research and development status of casting magnesium alloys including the commercial casting alloys and the new types casting alloys are reviewed,with more attention to microstructure and mechanical properties of modified-AZ91,AM60 and WE43 alloys with various additions,and new types of low cost casting alloys and high strength casting alloys.The modification and/or refinement of Mg2 Si phase in Mg-Al-Si based casting alloys by various additions are discussed and new purifying technologies for casting magnesium alloys are introduced to improve the performance.The modified AZ81 alloy with reduced impurities is found to have the tensile strength of 280 ± 6 MPa and elongation of 16% ± 0.7%.The fatigue strength of AZ91 D alloy could be obviously improved by addition of Ce and Nd.The Mg-16Gd-2Ag-0.3Zr alloy exhibits very high tensile and yield strengths（UTS：423 MPa and YS：328 MPa）;however,its elongation still needs to be improved.
基金financially supported by the National Key Research and Development Program of China(Project No.2016YFB0301100&Project No.2016YFB0700403)the Chongqing Academician Special Fund(Project No.cstc2018jcyj-yszx X0007&Project No.cstc2020yszx-jcyj X0001)+1 种基金Chongqing Research Program of Basic Research and Frontier Technology(Project No.cstc2019jcyj-msxm0438)the 111 Project(Project No.B16007)by the Ministry of Education and the State Administration of Foreign Experts Affairs of China。
文摘Research on magnesium alloys continues to attract great attention,with more than 3000 papers on magnesium and magnesium alloys published and indexed in SCI in 2020 alone.The results of bibliometric analyses show that microstructure control and mechanical properties of Mg alloys are continuously the main research focus,and the corrosion and protection of Mg alloys are still widely concerned.The emerging research hot spots are mainly on functional magnesium materials,such as Mg ion batteries,hydrogen storage Mg materials,and bio-magnesium alloys.Great contributions to the research and development of magnesium alloys in 2020 have been made by Chongqing University,Chinese Academy of Sciences,Central South University,Shanghai Jiaotong University,Northeastern University,Helmholtz Zentrum Geesthacht,etc.The directions for future research are suggested,including:1)the synergistic control of microstructures to achieve high-performance magnesium alloys with concurrent high strength and superior plasticity along with high corrosion resistance and low cost;2)further development of functional magnesium materials such as Mg batteries,hydrogen storage Mg materials,structural-functional materials and bio-magnesium materials;3)studies on the effective corrosion protection and control of degradation rate of magnesium alloys;4)further improvement of advanced processing technology on Mg alloys.
基金Supported by National Natural Science Foundation of China(Grant No.51605077)Science Challenge Project(Grant No.CKY2016212A506-0101)Science Fund for Creative Research Groups of NSFC(Grant No.51621064)
文摘Defect formation is a common problem in selective laser melting （SLM）. This paper provides a review of defect formation mechanisms in SLM. It sum- marizes the recent research outcomes on defect findings and classification, analyzes formation mechanisms of the common defects, such as porosities, incomplete fusion holes, and cracks. The paper discusses the effect of the process parameters on defect formation and the impact of defect formation on the mechanical properties of a fabri- cated part. Based on the discussion, the paper proposes strategies for defect suppression and control in SLM.
基金supported by the National Basic Research Program of China(973 Program)(Nos.2012CB619102 and 2012CB619100)the National Science Fund for Distinguished Young Scholars(No.51225101)+4 种基金the National Natural Science Foundation of China(No.31170909)the Research Fund for the Doctoral Program of Higher Education(No.20100001110011) the Natural Science Foundation of Heilongjiang Province(No. ZD201012)the Project for Supervisor of Excellent Doctoral Dissertation of Beijing(No.20121000101)the Guangdong Province Innovation R&D Team Project(No.201001 C0104669453)
文摘There is an increasing interest in the development of magnesium alloys both for industrial and biomedical applications. Industrial interest in magnesium alloys is based on strong demand of weight reduction of transportation vehicles for better fuel efficiency, so higher strength, and better ductility and corrosion resistance are required. Nevertheless, biomedical magnesium alloys require appropriate mechanical properties, suitable degradation rate in physiological environment, and what is most important, biosafety to human body. Rather than simply apply commercial magnesium alloys to biomedical field, new alloys should be designed from the point of view of nutriology and toxicology. This article provides a review of state-of-the-art of magnesium alloy implants and devices for orthopedic, cardiovascular and tissue engineering applications. Advances in new alloy design, novel structure design and surface modification are overviewed. The factors that influence the corrosion behavior of magnesium alloys are discussed and the strategy in the future development of biomedical magnesium alloys is proposed.
