乙型肝炎病毒X蛋白（hepatitis B virus X protein,HBx）全长154个氨基酸,与肝癌发生密切相关.为确定HBx的优势氨基酸序列和热点突变位点,在GenBank中下载所有HBx的氨基酸序列13950条,剔除插入突变、缺失突变和起始密码子非甲硫氨酸的序...乙型肝炎病毒X蛋白（hepatitis B virus X protein,HBx）全长154个氨基酸,与肝癌发生密切相关.为确定HBx的优势氨基酸序列和热点突变位点,在GenBank中下载所有HBx的氨基酸序列13950条,剔除插入突变、缺失突变和起始密码子非甲硫氨酸的序列,最后保留7126条.通过分析这7126条序列,计算出HBx每个位点的氨基酸分布情况,出现频率最高的氨基酸为该位点的优势氨基酸,其他氨基酸为突变氨基酸.154个位点的优势氨基酸组成HBx优势氨基酸序列.突变率〉10.0%的热点突变位点有32个.其中第36、42、44、87、88和127位氨基酸有4种（突变率〉1.0%）以上突变形式,具有较高的多态性.与肝癌密切相关的K130M/V131I双突变率为34.7%.通过7126条HBx序列与优势序列的同源性比较,随机选出其中50条序列（2条与优势序列同源性〈75%,48条同源性为76%~99%）,与23条参考序列及优势序列共同构建系统发生树.结果显示,HBx优势氨基酸序列属于基因型C,这与基因型C为全球主要流行型一致.本研究首次系统性分析了GenBank中HBx的优势序列,确定了32个HBx热点突变位点和6个多态性较高的位点,为基于HBx突变的基础和应用研究奠定了基础.展开更多
The economic development bring serious environmental problems to China, the quality of atmospheric environment has an important bearing on the forecast. Be aimed at the complexity and non-linear of the quality of atmo...The economic development bring serious environmental problems to China, the quality of atmospheric environment has an important bearing on the forecast. Be aimed at the complexity and non-linear of the quality of atmospheric environment, chaos theory has been put forward which takes full advantage of using date information. Based on the reconstruction of time-series phase space of the quality of atmospheric environment with the use of least squares support vector machine theory, the atmospheric environment prediction model was built up, and 25 years of historical data viewed as the raw data of the quality of the environment in Benxi City, giving a practical example, it shows that the results forecasted by the least squares support vector machine and the actual results match the better the forecast accuracy also meet the engineering application.展开更多
文摘乙型肝炎病毒X蛋白（hepatitis B virus X protein,HBx）全长154个氨基酸,与肝癌发生密切相关.为确定HBx的优势氨基酸序列和热点突变位点,在GenBank中下载所有HBx的氨基酸序列13950条,剔除插入突变、缺失突变和起始密码子非甲硫氨酸的序列,最后保留7126条.通过分析这7126条序列,计算出HBx每个位点的氨基酸分布情况,出现频率最高的氨基酸为该位点的优势氨基酸,其他氨基酸为突变氨基酸.154个位点的优势氨基酸组成HBx优势氨基酸序列.突变率〉10.0%的热点突变位点有32个.其中第36、42、44、87、88和127位氨基酸有4种（突变率〉1.0%）以上突变形式,具有较高的多态性.与肝癌密切相关的K130M/V131I双突变率为34.7%.通过7126条HBx序列与优势序列的同源性比较,随机选出其中50条序列（2条与优势序列同源性〈75%,48条同源性为76%~99%）,与23条参考序列及优势序列共同构建系统发生树.结果显示,HBx优势氨基酸序列属于基因型C,这与基因型C为全球主要流行型一致.本研究首次系统性分析了GenBank中HBx的优势序列,确定了32个HBx热点突变位点和6个多态性较高的位点,为基于HBx突变的基础和应用研究奠定了基础.
文摘The economic development bring serious environmental problems to China, the quality of atmospheric environment has an important bearing on the forecast. Be aimed at the complexity and non-linear of the quality of atmospheric environment, chaos theory has been put forward which takes full advantage of using date information. Based on the reconstruction of time-series phase space of the quality of atmospheric environment with the use of least squares support vector machine theory, the atmospheric environment prediction model was built up, and 25 years of historical data viewed as the raw data of the quality of the environment in Benxi City, giving a practical example, it shows that the results forecasted by the least squares support vector machine and the actual results match the better the forecast accuracy also meet the engineering application.
