Electroless nickel plating on AZ91D substrate with a new and eco-friendly pretreatment process based on tuning an electrochemical homogeneous surface was investigated. The morphology, deposition process, chemical comp...Electroless nickel plating on AZ91D substrate with a new and eco-friendly pretreatment process based on tuning an electrochemical homogeneous surface was investigated. The morphology, deposition process, chemical composition and microstructure of Ni-P coating were studied. It is indicated that β phases are selectively removed, producing a microstructural homogeneous surface and the subsequent uniform and compact Zn immersion layer. A defect-free and well adhesive Ni-P coating can be successfully obtained due to its uniform nucleation and growth based on such pretreatment. Potentiodynamic polarization and electrochemical impedance spectroscopy （EIS） tests reveal that Ni-P coating could significantly improve the corrosion resistance of AZ91D substrate.展开更多
目的探索组织均质前处理赘生物标本适宜条件,验证组织均质处理临床标本的使用效果,提高赘生物病原体检出率。方法首先通过定量培养,选择条件验证菌株的菌液稀释度。在不同温度、转速和时长条件下验证金黄色葡萄球菌、大肠埃希菌、近平...目的探索组织均质前处理赘生物标本适宜条件,验证组织均质处理临床标本的使用效果,提高赘生物病原体检出率。方法首先通过定量培养,选择条件验证菌株的菌液稀释度。在不同温度、转速和时长条件下验证金黄色葡萄球菌、大肠埃希菌、近平滑念珠菌、戈登链球菌及艾肯菌均质处理后的存活数。选择菌株存活数无差异的均质程序进行菌株和赘生物组织的同时处理,确定组织破碎程度较高和菌株存活数较多的最佳条件。最后进行临床赘生物标本均质处理,将均质后的标本进行增菌分离培养和染色镜检后统计阳性率,与传统剪碎、研磨方法进行比对。结果1麦氏浊度的菌悬液取10μL进行定量培养时1∶1000稀释是适宜的稀释倍数;在温度为4℃、-20℃及-80℃,转速和时长分别为6 m/s 1 min、4 m/s 1 min 30 s、4 m/s 1 min条件下,验证菌株的存活数与对照菌液差异无统计学意义(P>0.05);在-20℃放置30 min,6 m/s 1 min条件下,组织破碎效果和菌株存活状况最佳;30份感染性心内膜炎患者心脏瓣膜赘生物直接培养阳性率为20.0%,剪碎培养阳性率为16.7%,研磨培养阳性率为20.0%,均质直接培养阳性率为23.3%,均质增菌培养阳性率为36.7%,均质增菌培养联合镜检阳性率为76.7%。结论均质处理临床心脏瓣膜赘生物标本的最佳条件是6 m/s 1 min、-20℃;均质处理后培养阳性率明显提高;组织均质前处理后,培养联合镜检的方法能够进一步提高病原体检出率;在组织病原体分离培养中,均质处理的方法是目前最佳的前处理方法,推荐临床验证和使用。展开更多
基金Project(51371116)supported by the National Natural Science Foundation of ChinaProject(2009AA033501)supported by the Ministry of Science and Technology,China
文摘Electroless nickel plating on AZ91D substrate with a new and eco-friendly pretreatment process based on tuning an electrochemical homogeneous surface was investigated. The morphology, deposition process, chemical composition and microstructure of Ni-P coating were studied. It is indicated that β phases are selectively removed, producing a microstructural homogeneous surface and the subsequent uniform and compact Zn immersion layer. A defect-free and well adhesive Ni-P coating can be successfully obtained due to its uniform nucleation and growth based on such pretreatment. Potentiodynamic polarization and electrochemical impedance spectroscopy （EIS） tests reveal that Ni-P coating could significantly improve the corrosion resistance of AZ91D substrate.
文摘目的探索组织均质前处理赘生物标本适宜条件,验证组织均质处理临床标本的使用效果,提高赘生物病原体检出率。方法首先通过定量培养,选择条件验证菌株的菌液稀释度。在不同温度、转速和时长条件下验证金黄色葡萄球菌、大肠埃希菌、近平滑念珠菌、戈登链球菌及艾肯菌均质处理后的存活数。选择菌株存活数无差异的均质程序进行菌株和赘生物组织的同时处理,确定组织破碎程度较高和菌株存活数较多的最佳条件。最后进行临床赘生物标本均质处理,将均质后的标本进行增菌分离培养和染色镜检后统计阳性率,与传统剪碎、研磨方法进行比对。结果1麦氏浊度的菌悬液取10μL进行定量培养时1∶1000稀释是适宜的稀释倍数;在温度为4℃、-20℃及-80℃,转速和时长分别为6 m/s 1 min、4 m/s 1 min 30 s、4 m/s 1 min条件下,验证菌株的存活数与对照菌液差异无统计学意义(P>0.05);在-20℃放置30 min,6 m/s 1 min条件下,组织破碎效果和菌株存活状况最佳;30份感染性心内膜炎患者心脏瓣膜赘生物直接培养阳性率为20.0%,剪碎培养阳性率为16.7%,研磨培养阳性率为20.0%,均质直接培养阳性率为23.3%,均质增菌培养阳性率为36.7%,均质增菌培养联合镜检阳性率为76.7%。结论均质处理临床心脏瓣膜赘生物标本的最佳条件是6 m/s 1 min、-20℃;均质处理后培养阳性率明显提高;组织均质前处理后,培养联合镜检的方法能够进一步提高病原体检出率;在组织病原体分离培养中,均质处理的方法是目前最佳的前处理方法,推荐临床验证和使用。
