737MAX飞机半年内两次空难,全球停飞,各方针对事故原因及其事态的后续发展持续关注。狮航空难事件后波音发布的技术通告指出事故的关键因素是AOA(angle of attack-迎角)数据错误,但是同样的AOA传感器也安装在737NG系列飞机上,同样的事...737MAX飞机半年内两次空难,全球停飞,各方针对事故原因及其事态的后续发展持续关注。狮航空难事件后波音发布的技术通告指出事故的关键因素是AOA(angle of attack-迎角)数据错误,但是同样的AOA传感器也安装在737NG系列飞机上,同样的事故却没有发生在这系列飞机上。所以进一步的数据分析都指向Max系列飞机采用的全新技术MCAS(maneuvering characteristics augmentation system-机动特性增强系统),而波音公司一开始却否认了该技术和事故发生的直接关系,直到该系列飞机全球停飞后,波音才不得不承认该技术存在缺陷,而且目前所有恢复飞机认证的措施也都是围绕该技术的软件升级展开的。那么波音为什么在本已经很成功的机型上采用这一全新的技术,而这一技术为何又会导致事故频发,本文将探讨MCAS的来龙去脉。展开更多
Objective: The mucus production is an indicator for the histological grade of mucinous epithelial ovarian cancer (mEOC). In our previous study, Crk expression was targeted in the human ovarian mucinous adenocarcino...Objective: The mucus production is an indicator for the histological grade of mucinous epithelial ovarian cancer (mEOC). In our previous study, Crk expression was targeted in the human ovarian mucinous adenocarcinoma cell line MCAS through RNA interference, resulting in the establishment of Crk knock down cells. These cells exhibited decreased tumorigenic potential both in vitro and in vivo. The purpose of this study was to investigate if there is any change in the capability of forming mucus in these Crk knock down cells. Methods: Cytoplasmic periodic acid Schiff (PAS) staining and particle excluding assay were conducted to assess the mucus formation within and around cells, respectively. Additionally, the amount of mucus formed in tumor lumps from nude mice model was measured following HE and PAS staining. Results: The increased mucus production in Crk knockdown mEOC cells (MCAS) was manifested by increased number of enlarged cells filled with vacuoles-like mucus observed by phase-contrast microscope and cytoplasmic PAS staining; and enhanced mucus secretion was represented by the assembly of pericellular matrix in particle excluding assay and increased mucus area in tumor lumps from nude mice models. Conclusion: The course of carcinogenesis in mEOC is associated with the altered pattern of mucus production and secretion. The adaptor protein Crk is implicated in both pathways.展开更多
研究了聚磷酸铵APP、三聚氰胺氰尿酸盐MCA、乙酰丙酮锌以及ABS高胶粉对磷-氮复配无卤阻燃ABS材料的阻燃性能、力学性能及热学特性的影响。实验表明单独使用聚磷酸铵APP阻燃剂对ABS材料进行阻燃改性效果一般,阻燃等级无法达到V-0级别。将...研究了聚磷酸铵APP、三聚氰胺氰尿酸盐MCA、乙酰丙酮锌以及ABS高胶粉对磷-氮复配无卤阻燃ABS材料的阻燃性能、力学性能及热学特性的影响。实验表明单独使用聚磷酸铵APP阻燃剂对ABS材料进行阻燃改性效果一般,阻燃等级无法达到V-0级别。将APP与MCA复配使用后材料阻燃效果良好,能够达到1.6 mm V-0级别。在无卤阻燃ABS体系中添加部分ABS高胶粉能够改善阻燃ABS抗冲击性能不足的缺点,但会降低阻燃效果,添加部分乙酰丙酮锌能够将该影响消除,同时能提高阻燃ABS的抗冲击性能。展开更多
基金a grant from the National Natural Science Foundation of China(No.C30672432,No.30772330)the Natural Science Foundation of Chongqing City(No.2007BB5319)the Japan-China Sasakawa Medical Fellowship
文摘Objective: The mucus production is an indicator for the histological grade of mucinous epithelial ovarian cancer (mEOC). In our previous study, Crk expression was targeted in the human ovarian mucinous adenocarcinoma cell line MCAS through RNA interference, resulting in the establishment of Crk knock down cells. These cells exhibited decreased tumorigenic potential both in vitro and in vivo. The purpose of this study was to investigate if there is any change in the capability of forming mucus in these Crk knock down cells. Methods: Cytoplasmic periodic acid Schiff (PAS) staining and particle excluding assay were conducted to assess the mucus formation within and around cells, respectively. Additionally, the amount of mucus formed in tumor lumps from nude mice model was measured following HE and PAS staining. Results: The increased mucus production in Crk knockdown mEOC cells (MCAS) was manifested by increased number of enlarged cells filled with vacuoles-like mucus observed by phase-contrast microscope and cytoplasmic PAS staining; and enhanced mucus secretion was represented by the assembly of pericellular matrix in particle excluding assay and increased mucus area in tumor lumps from nude mice models. Conclusion: The course of carcinogenesis in mEOC is associated with the altered pattern of mucus production and secretion. The adaptor protein Crk is implicated in both pathways.
文摘研究了聚磷酸铵APP、三聚氰胺氰尿酸盐MCA、乙酰丙酮锌以及ABS高胶粉对磷-氮复配无卤阻燃ABS材料的阻燃性能、力学性能及热学特性的影响。实验表明单独使用聚磷酸铵APP阻燃剂对ABS材料进行阻燃改性效果一般,阻燃等级无法达到V-0级别。将APP与MCA复配使用后材料阻燃效果良好,能够达到1.6 mm V-0级别。在无卤阻燃ABS体系中添加部分ABS高胶粉能够改善阻燃ABS抗冲击性能不足的缺点,但会降低阻燃效果,添加部分乙酰丙酮锌能够将该影响消除,同时能提高阻燃ABS的抗冲击性能。