G115 steel,co-developed by China Iron and Steel Research Institute and Baosteel,is suitable for use in 600650℃ultra-supercritical boilers.Creep tests were carried out on a G115 hot extrusion tube at 625℃and a stress...G115 steel,co-developed by China Iron and Steel Research Institute and Baosteel,is suitable for use in 600650℃ultra-supercritical boilers.Creep tests were carried out on a G115 hot extrusion tube at 625℃and a stress of 130 MPa.Microstructure observation samples were obtained at different creep stages.The creep curve showed that the creep rate of G115 steel increased continuously after the creep test entered the steady-state stage,whereas fracture did not occur for an extended period of time.The scanning electron microscopy observation showed that the martensite lath did not appear to degenerate during the creep test,and its width increased.The transmission electron microscopy observation showed that the size and quantity of M 23 C 6 and the Laves phase increased;however,the increase in size was not obvious.The precipitation mainly gathered at the grain boundaries and the martensite lath boundaries,strengthening them.展开更多
目的分析CCDC115(Coiled-Coil Domain-Containing Protein 115)的蛋白性质,利用Ccdc115基因缺失的小鼠单核巨噬细胞白血病细胞(RAW264.7),探究CCDC115对胞内鼠伤寒沙门菌生存的影响,为开展CCDC115功能研究及调控胞内沙门菌生存的机制研...目的分析CCDC115(Coiled-Coil Domain-Containing Protein 115)的蛋白性质,利用Ccdc115基因缺失的小鼠单核巨噬细胞白血病细胞(RAW264.7),探究CCDC115对胞内鼠伤寒沙门菌生存的影响,为开展CCDC115功能研究及调控胞内沙门菌生存的机制研究提供理论基础。方法采用生物信息学分析,对CCDC115的基本性质进行探究。依据CRISPR/Cas9基因编辑技术构建RAW264.7-Ccdc115-KO细胞系。将鼠伤寒沙门菌感染RAW264.7及RAW264.7-Ccdc115-KO细胞,通过RT-qRCR、Western Blot、CFU(Colony-Forming Units)计数、酸化成像研究CCDC115在鼠伤寒沙门菌胞内生存中的作用。结果CCDC115是由2个α螺旋及中间无序区组成的不稳定蛋白,无跨膜结构域。成功构建敲除Ccdc115基因的RAW264.7细胞系。鼠伤寒沙门菌感染细胞后,在RAW264.7细胞中mRNA水平和蛋白水平CCDC115表达增加,并且在RAW264.7-Ccdc115-KO细胞内增殖数量是RAW264.7细胞的1.5倍。在吞噬体酸化成像中,鼠伤寒沙门菌吞噬体在RAW264.7细胞中发生酸化,而在RAW264.7-Ccdc115-KO细胞中没有发生酸化。结论成功构建RAW264.7-Ccdc115-KO细胞系;CCDC115在鼠伤寒沙门菌感染过程中表达增加,并可能通过使吞噬体发生酸化抑制鼠伤寒沙门菌在细胞内生存。展开更多
文摘G115 steel,co-developed by China Iron and Steel Research Institute and Baosteel,is suitable for use in 600650℃ultra-supercritical boilers.Creep tests were carried out on a G115 hot extrusion tube at 625℃and a stress of 130 MPa.Microstructure observation samples were obtained at different creep stages.The creep curve showed that the creep rate of G115 steel increased continuously after the creep test entered the steady-state stage,whereas fracture did not occur for an extended period of time.The scanning electron microscopy observation showed that the martensite lath did not appear to degenerate during the creep test,and its width increased.The transmission electron microscopy observation showed that the size and quantity of M 23 C 6 and the Laves phase increased;however,the increase in size was not obvious.The precipitation mainly gathered at the grain boundaries and the martensite lath boundaries,strengthening them.
