目的对两步磁珠法提取血浆游离DNA的方法进行评价,初步探讨血浆游离DNA定量对于肺癌患者实验诊断的意义。方法在健康志愿者血浆中掺入DNA标准品127 bp,208 bp和Quick-load~@100 bp DNA ladder(由100-1 500 bp DNA片段组成),采用两步磁...目的对两步磁珠法提取血浆游离DNA的方法进行评价,初步探讨血浆游离DNA定量对于肺癌患者实验诊断的意义。方法在健康志愿者血浆中掺入DNA标准品127 bp,208 bp和Quick-load~@100 bp DNA ladder(由100-1 500 bp DNA片段组成),采用两步磁珠法和分离柱提取法提取血浆中掺入的DNA标准品;用Qubit测定DNA浓度,安捷伦2100生物芯片分析仪和琼脂糖凝胶电泳检测分析DNA片段大小分布。用两步磁珠法和分离柱提取法分别提取15例肺癌患者的血浆cfDNA,利用安捷伦2100生物芯片分析仪和琼脂糖凝胶电泳比较两种方法提取的cf-DNA片段大小分布,分析cf-DNA浓度与肺癌分期的相关性。结果两步磁珠法第二步分离的DNA浓度与掺入标准品DNA(127 bp,208 bp)片段浓度呈正相关(r^2=0. 985 7,P <0. 001);两步磁珠法提取的Quick-load~@100 bp DNA ladder第一步分离的DNA片段≥300 bp,第二步分离的DNA片段≤300 bp,分离柱提取法重提取的Quick-load~@DNA ladder≤1 500 bp。两步磁珠法第二步分离的肺癌患者血浆cf-DNA浓度与肺癌分期呈正相关(r^2=0. 866 4,P=0. 004 9)。分离柱提取法提取的cf-DNA浓度与肺癌分期无显著相关性(r^2=0. 500 9,P=0. 214 5)。结论两步磁珠法可分别提取不同大小片段的DNA标准品,同时有效提取肺癌患者血浆中小片段游离DNA,且其浓度与肺癌分期呈正相关。展开更多
Aimed at the problem of classification of non-hydrocarbons of crude oil, the theoretical standpoint that the polarity of a compound depends on the whole structure and composition of molecule instead of a kind of heter...Aimed at the problem of classification of non-hydrocarbons of crude oil, the theoretical standpoint that the polarity of a compound depends on the whole structure and composition of molecule instead of a kind of heteroatom or its functional group was presented. A method was established for the systematically structural identification of nitric compounds in crude oil. The pre-fractionation of a crude oil sample into 7 fractions was performed by di- adsorption column chromatography with neutral aluminum oxide and silica gel. Subsequently, the individual components were obtained by using capillary column gas chromatography, and the types of compounds were detected by a mass spectrometer. In combination with a chemometric resolution, the compounds of fraction were further identified. This method can relieve the difficulty of classical analysis in identifying those species with very low contents or without being completely separated. The structures of 168 nitric compounds in a crude oil sample were determined by this method.展开更多
Detachment size determination with an acoustic method has been carried out for two interacting bubble plumes formed at neighboring needles in quiescent water. Two sets of needle pairs, one with 1.5mm and 0.8mm inner d...Detachment size determination with an acoustic method has been carried out for two interacting bubble plumes formed at neighboring needles in quiescent water. Two sets of needle pairs, one with 1.5mm and 0.8mm inner diameters and the other with the equal 1.5mm inner diameters, were separately used as the bubble pair injectors in the experiments. Consequently, four typical patterns of bubble plumes interaction could be observed in the two cases of needle pair matches. Through measuring the pressure pulses radiated by the bubble pairs immediately after their 'pinching-off ' and by making use of a sophisticated relation between oscillation frequency of volume mode and radius of gas bubble, the detachment size of the bubble plumes have been determined from the amplitude/frequency spectrum of the sound pressure pulses. The experimental results demonstrate that the acoustical method is valid in both of the interacting and non-interacting circumstances in bubble field and the bubble size measurements by this acoustical method agree well with the measurements from photographic analysis. Finally, a comparison has been made on the strong and weak points of the acoustical method with the other size determination methods.展开更多
文摘Aimed at the problem of classification of non-hydrocarbons of crude oil, the theoretical standpoint that the polarity of a compound depends on the whole structure and composition of molecule instead of a kind of heteroatom or its functional group was presented. A method was established for the systematically structural identification of nitric compounds in crude oil. The pre-fractionation of a crude oil sample into 7 fractions was performed by di- adsorption column chromatography with neutral aluminum oxide and silica gel. Subsequently, the individual components were obtained by using capillary column gas chromatography, and the types of compounds were detected by a mass spectrometer. In combination with a chemometric resolution, the compounds of fraction were further identified. This method can relieve the difficulty of classical analysis in identifying those species with very low contents or without being completely separated. The structures of 168 nitric compounds in a crude oil sample were determined by this method.
基金Supported by the Post-Doctorate Science Foundation.
文摘Detachment size determination with an acoustic method has been carried out for two interacting bubble plumes formed at neighboring needles in quiescent water. Two sets of needle pairs, one with 1.5mm and 0.8mm inner diameters and the other with the equal 1.5mm inner diameters, were separately used as the bubble pair injectors in the experiments. Consequently, four typical patterns of bubble plumes interaction could be observed in the two cases of needle pair matches. Through measuring the pressure pulses radiated by the bubble pairs immediately after their 'pinching-off ' and by making use of a sophisticated relation between oscillation frequency of volume mode and radius of gas bubble, the detachment size of the bubble plumes have been determined from the amplitude/frequency spectrum of the sound pressure pulses. The experimental results demonstrate that the acoustical method is valid in both of the interacting and non-interacting circumstances in bubble field and the bubble size measurements by this acoustical method agree well with the measurements from photographic analysis. Finally, a comparison has been made on the strong and weak points of the acoustical method with the other size determination methods.
