Bicyclic Sesquiterpanes （BSs） are ubiquitous components of crude oils and ancient sediments. BSs in crude oils and diesel oil were identified and characterized, the effects of moderate weathering on BS distributions...Bicyclic Sesquiterpanes （BSs） are ubiquitous components of crude oils and ancient sediments. BSs in crude oils and diesel oil were identified and characterized, the effects of moderate weathering on BS distributions were discussed, and a methodology using diagnostic indices of BSs was developed for oil correlation and dif- ferentiation. The results showed that crude oils and oil products had different abundances and distributions of BSs and, consequently, resulted in different diagnostic ratios. The selected diagnostic ratio indices of BSs, such as BS4/BS5 （ratio of 4,4,8,9,9-pentamethyl-decahydronaphthalene to 8/3 （H）-drimane）, BS6/BS5 （ratio of 4,4,9,9,10-pentamethyl-decahydronaphthalene to 8/3 （H）-drimane）, BS8/BS9 （ratio of the second peak to the third peak of C16 sequiterpane）, and BS8/BSIO （ratio of C16 sequiterpane to 8fl （H）-homodrimane）, still maintained better stabilities （%RSD 〈 5%） after weathering for 30 d. The longer weathering process （150 d） had some effect on such ratios （5% 〈 %RSD 〈 10%）. The facts of the uniqueness, abundance in petroleum, and chemical stability of BSs enable them to be suitable as an effective diagnostic means for identifying spilled oil with moderate weathering, particularly for lighter refined product samples that are difficult to identify by current techniques.展开更多
Objective： The aim of the study was to construct miRNA-451 expression vector pLMP-miRNA-451 which could help identify the functions of miRNA-451 in SGC-7901 cell. Methods： Total RNA was extracted from SGC-7901 cells...Objective： The aim of the study was to construct miRNA-451 expression vector pLMP-miRNA-451 which could help identify the functions of miRNA-451 in SGC-7901 cell. Methods： Total RNA was extracted from SGC-7901 cells to synthesized cDNA. The synthesized cDNA encoding pre-miRNA-451 was amplified by polymerase chain reaction （PCR）. The PCR product was separated by electrophoresis on 1% agarose gel and then recovered and purified. The purified cDNA fragments of miRNA-451 precursor sequence was then ligated with vector pLMP for 1 h by using DNA ligase to form pLMP- miRNA-451 plasmid. After that, the pLMP-miRNA-451 plasmid was transformed into E. coli DH5a strain expression system to clone and amplificate. The purified pLMP-miRNA-451 extracted from E. coli DH5a via transformation and clone screening was identificatied with restriction enzyme digestion and DNA sequencing. At last, pLMP-miRNA-451 was transfected into SGC-7901 cells with lip2000. Real-time PCR was used for detection of the miRNA-451, the transfection efficiency was ob- served under fluorescence microscopy and cell counting kit-8 assay was conduced to evaluate the effect of miRNA-451 on SGC-7901 cell proliferation. Results： Our results showed that pLMP-miRNA-451 expression vector was not only constructed successfully and effectively infected SGC-7901 cells, but also could repress the SGC-7901 cell proliferation. Conclusion： The constructed plasmid pLMP-miRNA-451 could used for further studies of miRNA-451 in SGC-7901 cell lines.展开更多
基金Key Projects in the Yantai Science & Technology Pillar Program under contract No. 2011060the National Natural Science Foundation of China under contract Nos 40806048 and 41206089Hundred Talents Program of Chinese Academy of Sciences
文摘Bicyclic Sesquiterpanes （BSs） are ubiquitous components of crude oils and ancient sediments. BSs in crude oils and diesel oil were identified and characterized, the effects of moderate weathering on BS distributions were discussed, and a methodology using diagnostic indices of BSs was developed for oil correlation and dif- ferentiation. The results showed that crude oils and oil products had different abundances and distributions of BSs and, consequently, resulted in different diagnostic ratios. The selected diagnostic ratio indices of BSs, such as BS4/BS5 （ratio of 4,4,8,9,9-pentamethyl-decahydronaphthalene to 8/3 （H）-drimane）, BS6/BS5 （ratio of 4,4,9,9,10-pentamethyl-decahydronaphthalene to 8/3 （H）-drimane）, BS8/BS9 （ratio of the second peak to the third peak of C16 sequiterpane）, and BS8/BSIO （ratio of C16 sequiterpane to 8fl （H）-homodrimane）, still maintained better stabilities （%RSD 〈 5%） after weathering for 30 d. The longer weathering process （150 d） had some effect on such ratios （5% 〈 %RSD 〈 10%）. The facts of the uniqueness, abundance in petroleum, and chemical stability of BSs enable them to be suitable as an effective diagnostic means for identifying spilled oil with moderate weathering, particularly for lighter refined product samples that are difficult to identify by current techniques.
基金supported by a grant from the Natural Science Foundation of China (No. 8100098)
文摘Objective： The aim of the study was to construct miRNA-451 expression vector pLMP-miRNA-451 which could help identify the functions of miRNA-451 in SGC-7901 cell. Methods： Total RNA was extracted from SGC-7901 cells to synthesized cDNA. The synthesized cDNA encoding pre-miRNA-451 was amplified by polymerase chain reaction （PCR）. The PCR product was separated by electrophoresis on 1% agarose gel and then recovered and purified. The purified cDNA fragments of miRNA-451 precursor sequence was then ligated with vector pLMP for 1 h by using DNA ligase to form pLMP- miRNA-451 plasmid. After that, the pLMP-miRNA-451 plasmid was transformed into E. coli DH5a strain expression system to clone and amplificate. The purified pLMP-miRNA-451 extracted from E. coli DH5a via transformation and clone screening was identificatied with restriction enzyme digestion and DNA sequencing. At last, pLMP-miRNA-451 was transfected into SGC-7901 cells with lip2000. Real-time PCR was used for detection of the miRNA-451, the transfection efficiency was ob- served under fluorescence microscopy and cell counting kit-8 assay was conduced to evaluate the effect of miRNA-451 on SGC-7901 cell proliferation. Results： Our results showed that pLMP-miRNA-451 expression vector was not only constructed successfully and effectively infected SGC-7901 cells, but also could repress the SGC-7901 cell proliferation. Conclusion： The constructed plasmid pLMP-miRNA-451 could used for further studies of miRNA-451 in SGC-7901 cell lines.
