以罗氏沼虾转录组数据为数据来源,通过研究罗氏沼虾转录组的密码子使用参数(如有效密码子的数量和相关密码子碱基的具体组成信息等),并且采用Codon W 1.4.4深入开展了统计和计算.研究结果显示,同义密码子第三位核苷酸和表达基因密码子G...以罗氏沼虾转录组数据为数据来源,通过研究罗氏沼虾转录组的密码子使用参数(如有效密码子的数量和相关密码子碱基的具体组成信息等),并且采用Codon W 1.4.4深入开展了统计和计算.研究结果显示,同义密码子第三位核苷酸和表达基因密码子GC含量均值分别为0.40和0.45.从整体上看,ENC的平均值等于52.72,其中绝大部分的ENC值小于35.采用高频密码子的研究方法获得GAU、GAA、UUU、AAU、CCA等5个高频密码子.通过最优码子分析法确定16个最优密码子,编码10个氨基酸,最优密码子除UUG外均以A/T结尾.而且把它和大肠杆菌、酵母、果蝇以及人类等6种生物的密码子使用频率开展比较,结果表明,与大肠杆菌和果蝇存在较大差异,而与酵母最为接近.研究结果可为罗氏沼虾功能基因和分子育种等提供理论基础.展开更多
A continuous wave carbon dioxide (CO2) laser (λ=10.6μm) was employed to treat the surface of Si3N4 MOR (modulus of rupture) bars. The effects of the CO2 laser process on physical and mechanical properties of ground ...A continuous wave carbon dioxide (CO2) laser (λ=10.6μm) was employed to treat the surface of Si3N4 MOR (modulus of rupture) bars. The effects of the CO2 laser process on physical and mechanical properties of ground Si3N4 samples were investigated. Scanning electron microscopy (SEM) analysis shows that the area occupied by cavities and fracture is decreased by about 49.4% after laser treatments. Cross-sectional metallography results indicate that the secondary YSiAlON phase in the Si3N4 ceramic is softened/melted and flowed into the defects. Four-point bending tests show that the flexural strength of the treated samples is improved to 10.9%. Fractographic analysis show that the fracture origins move from the surface to subsurface. It is concluded that laser surface processing have significant effects on fracture behavior of flexure Si3N4 ceramic.展开更多
In recent years, the indications of cardiac pacing have extended continuously with the rapid development of pacing technique. Pacemaker treatment has not only limited in arrhythmias of bradycardia and the number of pa...In recent years, the indications of cardiac pacing have extended continuously with the rapid development of pacing technique. Pacemaker treatment has not only limited in arrhythmias of bradycardia and the number of pacemaker treatment has increased year by year. However, more and more new congestive heart failure （ CHF ） and aggravated CHF have appeared in patients after pacing therapy. Therefore, it is a hot topic that how to select reasonable pacing mode to reduce CHF occurrence or relieve CHF symptoms in patients with CHF.展开更多
文摘以罗氏沼虾转录组数据为数据来源,通过研究罗氏沼虾转录组的密码子使用参数(如有效密码子的数量和相关密码子碱基的具体组成信息等),并且采用Codon W 1.4.4深入开展了统计和计算.研究结果显示,同义密码子第三位核苷酸和表达基因密码子GC含量均值分别为0.40和0.45.从整体上看,ENC的平均值等于52.72,其中绝大部分的ENC值小于35.采用高频密码子的研究方法获得GAU、GAA、UUU、AAU、CCA等5个高频密码子.通过最优码子分析法确定16个最优密码子,编码10个氨基酸,最优密码子除UUG外均以A/T结尾.而且把它和大肠杆菌、酵母、果蝇以及人类等6种生物的密码子使用频率开展比较,结果表明,与大肠杆菌和果蝇存在较大差异,而与酵母最为接近.研究结果可为罗氏沼虾功能基因和分子育种等提供理论基础.
基金Project(DMI-0085233) supported by the National Science Foundation of USA
文摘A continuous wave carbon dioxide (CO2) laser (λ=10.6μm) was employed to treat the surface of Si3N4 MOR (modulus of rupture) bars. The effects of the CO2 laser process on physical and mechanical properties of ground Si3N4 samples were investigated. Scanning electron microscopy (SEM) analysis shows that the area occupied by cavities and fracture is decreased by about 49.4% after laser treatments. Cross-sectional metallography results indicate that the secondary YSiAlON phase in the Si3N4 ceramic is softened/melted and flowed into the defects. Four-point bending tests show that the flexural strength of the treated samples is improved to 10.9%. Fractographic analysis show that the fracture origins move from the surface to subsurface. It is concluded that laser surface processing have significant effects on fracture behavior of flexure Si3N4 ceramic.
文摘In recent years, the indications of cardiac pacing have extended continuously with the rapid development of pacing technique. Pacemaker treatment has not only limited in arrhythmias of bradycardia and the number of pacemaker treatment has increased year by year. However, more and more new congestive heart failure （ CHF ） and aggravated CHF have appeared in patients after pacing therapy. Therefore, it is a hot topic that how to select reasonable pacing mode to reduce CHF occurrence or relieve CHF symptoms in patients with CHF.
