背景:当前针对患者骨健康/骨密度相关疾患结局指标的影响,传统太极功法干预仍然存在较大的争议,亟待作进一步探讨。目的:系统评价传统太极功法干预对改善骨密度流失的临床疗效与安全性。方法:通过计算机对中国知网CNKI、万方、维普VIP...背景:当前针对患者骨健康/骨密度相关疾患结局指标的影响,传统太极功法干预仍然存在较大的争议,亟待作进一步探讨。目的:系统评价传统太极功法干预对改善骨密度流失的临床疗效与安全性。方法:通过计算机对中国知网CNKI、万方、维普VIP和中国生物医学文献数据库、以及国外数据库PubMed、MEDLINE、EMbase、CochraneLibrary等进行全面检索;配合对大学图书馆的馆藏期刊进行手工检索,检索时间截于2019年1月;系统搜集传统太极功法(包括太极拳、太极推手、太极柔力球等)干预对骨健康/骨密度相关疾患结局指标影响的随机对照研究(RCT)文献。参考Cochrane系统评价方法进行文献筛选、资料提取以及方法学质量评价;并采用Rev Man 5.3软件进行Meta分析。结果与结论:共纳入14篇文献(16个RCT研究),Meta分析结果表明:接受传统太极功法干预后,脊柱腰椎L2-4骨密度(SMD=0.40,95%CI[0.16,0.65],P=0.001)、以及股骨颈骨密度(SMD=0.75,95%CI [0.27,1.24],P=0.002)改善方面均优于对照组;然而在Ward’s三角骨密度(SMD=0.50,95%CI[-0.10,1.10],P=0.10)、股骨干骨密度(SMD=0.16,95%CI[-0.11,0.44],P=0.25)、股骨近端转子骨密度(SMD=0.54,95%CI[-0.01,1.09],P=0.05)、以及桡骨远端1/3处骨密度(SMD=0.20,95%CI[-0.26,0.66],P=0.040)与对照组比较,组间差异无统计学意义;且传统太极功法干预尚未发现严重不良事件。当前证据发现,传统太极功法干预在特定人群(例如老年人、骨质疏松人群、围绝经期与绝经后妇女)脊柱腰椎、股骨颈等部位的骨密度流失改善方面疗效明确,不良反应较少。鉴于纳入文献数量偏少以及研究本身局限性,有待开展高质量的、设计严谨的临床试验予以进一步验证。展开更多
In the present investigation, electroless Ni-Cu-P/n-TiN composite coating was prepared using alkaline citrate-based bath. X-ray diffraction （XRD）, scanning electron microscopy（SEM）, energy-dispersive spectroscopy...In the present investigation, electroless Ni-Cu-P/n-TiN composite coating was prepared using alkaline citrate-based bath. X-ray diffraction （XRD）, scanning electron microscopy（SEM）, energy-dispersive spectroscopy（EDS）, electrochemical measurements, weight loss tests and Raman spectrometer were used to character the properties of the coating. As the Cu content increased from 7.3 wt% to 24.8 wt%, the corrosion current density of the Ni-Cu-P/n-TiN coating decreased from 10.80 to 4.34 ~tA. And the inclusion of Cu in NiP alloy resulted in refinement and less porosity in microstructure. The addition of TiN resulted in a slight decline in anti-corrosion property of the coating. As the mass loss test showed, Ni-24.8%Cu-P exhibited perfect corrosion resistance. Studies by Raman spectroscopy on coatings proved that Cu（II）3（PO4）（OH）3, Cu（OH）2 and CuO were examined while no compound of nickel was found, and Cu exhibited preferred corrosion in saline solution, providing cathodic protection to Ni alloy.展开更多
One of the most important and effective hardware elements for improvement of efficiency and power density of proton exchange membrane fuel cells is the flow field plate. The design and the pattern of the flow field pl...One of the most important and effective hardware elements for improvement of efficiency and power density of proton exchange membrane fuel cells is the flow field plate. The design and the pattern of the flow field plate have a considerable effect on the effectiveness of mass transport as well as on the electrochemical reactions inside the cell. The configuration of the flow field plate aims at ensuring a low pressure-drop over all channels in the stack. In this work, a FPFFP （fractal parallel flow field plate）, with bio-inspired configuration by insertion of fractals in a classic PFFP （parallel flow field plate）, is proposed, increasing the flow area of the hydrogen at anode side without increasing the section＇s area of the flow field plate. By simulating was observed that, the use of channels in fractal shape can increase the hydrogen flow area without occuring pressure loss in the cell. The fluid dynamic behavior in the FPFFP at smaller scales was replicated in the same plate, with better advantage of the active area of the electrode. Increasing the hydrogen flow area without causing pressure loss could be a good tactic to increase the power density of fuel cells, and consequently improving the cell performance.展开更多
文摘背景:当前针对患者骨健康/骨密度相关疾患结局指标的影响,传统太极功法干预仍然存在较大的争议,亟待作进一步探讨。目的:系统评价传统太极功法干预对改善骨密度流失的临床疗效与安全性。方法:通过计算机对中国知网CNKI、万方、维普VIP和中国生物医学文献数据库、以及国外数据库PubMed、MEDLINE、EMbase、CochraneLibrary等进行全面检索;配合对大学图书馆的馆藏期刊进行手工检索,检索时间截于2019年1月;系统搜集传统太极功法(包括太极拳、太极推手、太极柔力球等)干预对骨健康/骨密度相关疾患结局指标影响的随机对照研究(RCT)文献。参考Cochrane系统评价方法进行文献筛选、资料提取以及方法学质量评价;并采用Rev Man 5.3软件进行Meta分析。结果与结论:共纳入14篇文献(16个RCT研究),Meta分析结果表明:接受传统太极功法干预后,脊柱腰椎L2-4骨密度(SMD=0.40,95%CI[0.16,0.65],P=0.001)、以及股骨颈骨密度(SMD=0.75,95%CI [0.27,1.24],P=0.002)改善方面均优于对照组;然而在Ward’s三角骨密度(SMD=0.50,95%CI[-0.10,1.10],P=0.10)、股骨干骨密度(SMD=0.16,95%CI[-0.11,0.44],P=0.25)、股骨近端转子骨密度(SMD=0.54,95%CI[-0.01,1.09],P=0.05)、以及桡骨远端1/3处骨密度(SMD=0.20,95%CI[-0.26,0.66],P=0.040)与对照组比较,组间差异无统计学意义;且传统太极功法干预尚未发现严重不良事件。当前证据发现,传统太极功法干预在特定人群(例如老年人、骨质疏松人群、围绝经期与绝经后妇女)脊柱腰椎、股骨颈等部位的骨密度流失改善方面疗效明确,不良反应较少。鉴于纳入文献数量偏少以及研究本身局限性,有待开展高质量的、设计严谨的临床试验予以进一步验证。
基金Project(K1403375-11)supported by Science and Technology Planning Project of Changsha,ChinaProject(2015D009)supported by the Planned Science and Technology Project of Qingyuan City,ChinaProject(2015B04)supported by the Planned Science and Technology Project of Qingcheng District,Qingyuan City,China
文摘In the present investigation, electroless Ni-Cu-P/n-TiN composite coating was prepared using alkaline citrate-based bath. X-ray diffraction （XRD）, scanning electron microscopy（SEM）, energy-dispersive spectroscopy（EDS）, electrochemical measurements, weight loss tests and Raman spectrometer were used to character the properties of the coating. As the Cu content increased from 7.3 wt% to 24.8 wt%, the corrosion current density of the Ni-Cu-P/n-TiN coating decreased from 10.80 to 4.34 ~tA. And the inclusion of Cu in NiP alloy resulted in refinement and less porosity in microstructure. The addition of TiN resulted in a slight decline in anti-corrosion property of the coating. As the mass loss test showed, Ni-24.8%Cu-P exhibited perfect corrosion resistance. Studies by Raman spectroscopy on coatings proved that Cu（II）3（PO4）（OH）3, Cu（OH）2 and CuO were examined while no compound of nickel was found, and Cu exhibited preferred corrosion in saline solution, providing cathodic protection to Ni alloy.
文摘One of the most important and effective hardware elements for improvement of efficiency and power density of proton exchange membrane fuel cells is the flow field plate. The design and the pattern of the flow field plate have a considerable effect on the effectiveness of mass transport as well as on the electrochemical reactions inside the cell. The configuration of the flow field plate aims at ensuring a low pressure-drop over all channels in the stack. In this work, a FPFFP （fractal parallel flow field plate）, with bio-inspired configuration by insertion of fractals in a classic PFFP （parallel flow field plate）, is proposed, increasing the flow area of the hydrogen at anode side without increasing the section＇s area of the flow field plate. By simulating was observed that, the use of channels in fractal shape can increase the hydrogen flow area without occuring pressure loss in the cell. The fluid dynamic behavior in the FPFFP at smaller scales was replicated in the same plate, with better advantage of the active area of the electrode. Increasing the hydrogen flow area without causing pressure loss could be a good tactic to increase the power density of fuel cells, and consequently improving the cell performance.
