To enhance the gasoline octane number,low-octane linear n-alkanes should be converted into their high-octane di-branched isomers via n-alkane hydroisomerization.Therefore,hierarchical SAPO-11-based catalysts are prepa...To enhance the gasoline octane number,low-octane linear n-alkanes should be converted into their high-octane di-branched isomers via n-alkane hydroisomerization.Therefore,hierarchical SAPO-11-based catalysts are prepared by adding different contents of sodium dodecylbenzene sulfonate(SDBS),and they are applied in n-nonane hydroisomerization.When n(SDBS)/n(SiO2)is less than or equal to 0.125,the synthesized hierarchical molecular sieves are all pure SAPO-11,and as the SDBS content increases,the submicron particle size decreases,and the external surface area(ESA)increases.Additionally,these hierarchical SAPO-11 have smaller submicron particles and higher ESA values than conventional SAPO-11.When n(SDBS)/n(SiO2)is greater than 0.125,with increasing SDBS content(n(SDBS)/n(SiO2)=0.25),the synthesized SAPO-11 contains amorphous materials,which leads to a decline in the ESA;with the further increase in SDBS content(n(SDBS)/n(SiO2)=0.5),the products are all amorphous materials.These results indicate that in the case of n(SDBS)/n(SiO2)=0.125,the synthesized SAPO-11 molecular sieve(S–S3)has the most external Brønsted acid centers and the highest ESA of these SAPO-11,and these advantages favor generation of the di-branched isomers in hydrocarbon hydroisomerization.Among these Pt/SAPO-11 catalysts,Pt/S–S3 displays the highest selectivity to entire isomers(83.4%),the highest selectivity to di-branched isomers(28.1%)and the minimum hydrocracking selectivity(15.7%)in n-nonane hydroisomerization.展开更多
目的:探讨不同梯度浓度顺铂(CDDP)处理不同肺癌细胞后新发现的剪接因子SRSF7 m RNA异构体在同浓度CDDP处理后不同的细胞中的水平变化。方法:采用梯度浓度的CDDP处理肺癌细胞A549(8、18、24、32、40、48及56μmol/L)和H1299(12、24、36...目的:探讨不同梯度浓度顺铂(CDDP)处理不同肺癌细胞后新发现的剪接因子SRSF7 m RNA异构体在同浓度CDDP处理后不同的细胞中的水平变化。方法:采用梯度浓度的CDDP处理肺癌细胞A549(8、18、24、32、40、48及56μmol/L)和H1299(12、24、36、48、60、72及84μmol/L),处理24 h后提取总RNA,进行RT-PCR检测SRSF7 m RNA剪接异构体,并选取NCBI中未确定的异构体进行TA克隆后测序并分析鉴定异构体类型;用56μmol/L的CDDP处理人胚肾细胞293FT,宫颈癌细胞Ca Ski、Si Ha、C33A细胞24 h,提取总RNA后验证新发现的SRSF7 m RNA剪切异构体是否存在这些细胞中。结果:发现3种新的SRSF7 m RNA剪接异构体(分别标记为New1、New2及New3),在肺癌细胞A549、H1299,人胚肾细胞293FT,宫颈癌细胞Ca Ski、Si Ha、C33A细胞等多种肿瘤细胞中均存在,根据NCBI的预测New1,New2,New3异构体均为非编码蛋白的m RNA异构体,随着处理CDDP浓度的增加,其比例明显上升;而编码蛋白的m RNA异构体a和(或)b所占比例明显下降;同时SRSF7的总m RNA水平逐渐降低。结论:新发现的3种非编码的m RNA异构体的变化揭示细胞可能通过SRSF7自身的m RNA选择性剪接来应对DNA损伤。展开更多
1,3-偶极环加成反应有多种选择性,因此产物往往也是由多个异构体组成.天然产物青藤碱进行1,3-偶极环加成反应杂环化时,产物理论上有四个异构体,实验中只发现两个异构体.本文分析了青藤碱1,3-偶极环加成反应中的选择性,再根据产物的1 H ...1,3-偶极环加成反应有多种选择性,因此产物往往也是由多个异构体组成.天然产物青藤碱进行1,3-偶极环加成反应杂环化时,产物理论上有四个异构体,实验中只发现两个异构体.本文分析了青藤碱1,3-偶极环加成反应中的选择性,再根据产物的1 H NMR、13C NMR、NOESY相关谱、电子效应、空间效应的分析,结合理论计算和软件模拟,最终确定了所得两种产物异构体-1和异构体-2的构型.本文的推定方法,在判定具有类似电子效应和空间效应的1,3-偶极环加成反应产物结构时,能起到一定的借鉴作用.展开更多
A copper-catalyzed stereoselective 1,3-dipolar cycloaddition of methyleneindolinones and N,N0-cyclic azomethine imines has been developed under mild reaction conditions.The spiro[pyrazolidin-3,30-oxindoles] were obtai...A copper-catalyzed stereoselective 1,3-dipolar cycloaddition of methyleneindolinones and N,N0-cyclic azomethine imines has been developed under mild reaction conditions.The spiro[pyrazolidin-3,30-oxindoles] were obtained in moderate to high isolated yields（up to 82%） with good stereoselevtivities（up to 15：1） in the presence of 5 mol% of Cu（OAc）2at room temperature.展开更多
基金The authors gratefully acknowledge the financial support of the National Natural Science Foundation of China(Grant No.21978323)。
文摘To enhance the gasoline octane number,low-octane linear n-alkanes should be converted into their high-octane di-branched isomers via n-alkane hydroisomerization.Therefore,hierarchical SAPO-11-based catalysts are prepared by adding different contents of sodium dodecylbenzene sulfonate(SDBS),and they are applied in n-nonane hydroisomerization.When n(SDBS)/n(SiO2)is less than or equal to 0.125,the synthesized hierarchical molecular sieves are all pure SAPO-11,and as the SDBS content increases,the submicron particle size decreases,and the external surface area(ESA)increases.Additionally,these hierarchical SAPO-11 have smaller submicron particles and higher ESA values than conventional SAPO-11.When n(SDBS)/n(SiO2)is greater than 0.125,with increasing SDBS content(n(SDBS)/n(SiO2)=0.25),the synthesized SAPO-11 contains amorphous materials,which leads to a decline in the ESA;with the further increase in SDBS content(n(SDBS)/n(SiO2)=0.5),the products are all amorphous materials.These results indicate that in the case of n(SDBS)/n(SiO2)=0.125,the synthesized SAPO-11 molecular sieve(S–S3)has the most external Brønsted acid centers and the highest ESA of these SAPO-11,and these advantages favor generation of the di-branched isomers in hydrocarbon hydroisomerization.Among these Pt/SAPO-11 catalysts,Pt/S–S3 displays the highest selectivity to entire isomers(83.4%),the highest selectivity to di-branched isomers(28.1%)and the minimum hydrocracking selectivity(15.7%)in n-nonane hydroisomerization.
文摘目的:探讨不同梯度浓度顺铂(CDDP)处理不同肺癌细胞后新发现的剪接因子SRSF7 m RNA异构体在同浓度CDDP处理后不同的细胞中的水平变化。方法:采用梯度浓度的CDDP处理肺癌细胞A549(8、18、24、32、40、48及56μmol/L)和H1299(12、24、36、48、60、72及84μmol/L),处理24 h后提取总RNA,进行RT-PCR检测SRSF7 m RNA剪接异构体,并选取NCBI中未确定的异构体进行TA克隆后测序并分析鉴定异构体类型;用56μmol/L的CDDP处理人胚肾细胞293FT,宫颈癌细胞Ca Ski、Si Ha、C33A细胞24 h,提取总RNA后验证新发现的SRSF7 m RNA剪切异构体是否存在这些细胞中。结果:发现3种新的SRSF7 m RNA剪接异构体(分别标记为New1、New2及New3),在肺癌细胞A549、H1299,人胚肾细胞293FT,宫颈癌细胞Ca Ski、Si Ha、C33A细胞等多种肿瘤细胞中均存在,根据NCBI的预测New1,New2,New3异构体均为非编码蛋白的m RNA异构体,随着处理CDDP浓度的增加,其比例明显上升;而编码蛋白的m RNA异构体a和(或)b所占比例明显下降;同时SRSF7的总m RNA水平逐渐降低。结论:新发现的3种非编码的m RNA异构体的变化揭示细胞可能通过SRSF7自身的m RNA选择性剪接来应对DNA损伤。
文摘1,3-偶极环加成反应有多种选择性,因此产物往往也是由多个异构体组成.天然产物青藤碱进行1,3-偶极环加成反应杂环化时,产物理论上有四个异构体,实验中只发现两个异构体.本文分析了青藤碱1,3-偶极环加成反应中的选择性,再根据产物的1 H NMR、13C NMR、NOESY相关谱、电子效应、空间效应的分析,结合理论计算和软件模拟,最终确定了所得两种产物异构体-1和异构体-2的构型.本文的推定方法,在判定具有类似电子效应和空间效应的1,3-偶极环加成反应产物结构时,能起到一定的借鉴作用.
基金the National Natural Science Foundation of China (No.21172023)Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD) and STD of Jiangsu Province for their financial supports
文摘A copper-catalyzed stereoselective 1,3-dipolar cycloaddition of methyleneindolinones and N,N0-cyclic azomethine imines has been developed under mild reaction conditions.The spiro[pyrazolidin-3,30-oxindoles] were obtained in moderate to high isolated yields（up to 82%） with good stereoselevtivities（up to 15：1） in the presence of 5 mol% of Cu（OAc）2at room temperature.
基金the National Natural Science Foundation of China(21531003,21501024 and 21971035)Jilin Scientific and Technological Development Program(20170101198JC and 20190103017JH)+2 种基金Jilin Education Office(JJKH20180015KJ)“111”Program(B18012)open projects from the State Key Laboratory of Inorganic Synthesis&Preparative Chemistry and State Key Laboratory of Heavy Oil Processing(2018-8,SKLOP201902003)。
