A solid acid catalyst has been prepared by grafting Boron trifluoride on mesoporous molecular sieve MCM 41 and characterized by XRD and FTIR techniques. The XRD and FTIR results indicated that the BF 3·Et 2O inte...A solid acid catalyst has been prepared by grafting Boron trifluoride on mesoporous molecular sieve MCM 41 and characterized by XRD and FTIR techniques. The XRD and FTIR results indicated that the BF 3·Et 2O interlocks with the silicon groups of MCM 41 surface to form strong solid acid. The solid acid catalyst would effectively promote the opening of epichlorohydrin with isobutanol to form 1 isobutoxy 3 chloropropanol, and showed a nice activity and selectivity.展开更多
Epigenetic information carried by histone modifications not only reflects the state of gene expression,but also participates in the maintenance of chromatin states and the regulation of gene expression.Recycling of pa...Epigenetic information carried by histone modifications not only reflects the state of gene expression,but also participates in the maintenance of chromatin states and the regulation of gene expression.Recycling of parental histones to daughter chromatin after DNA replication is vital to mitotic inheritance of epigenetic information and the maintenance of cell identity,because the locus-specific modifications of the parental histones need to be maintained.To assess the precision of parental histone recycling,we developed a synthetic local label-chasing system in budding yeast Saccharomyces cerevisiae.Using this system,we observed that parental histone H3 can be recycled to their original position,thereby recovering their position information after DNA replication at all tested loci,including heterochromatin boundary,non-transcribed region,and actively transcribed regions.Moreover,the recycling rate appears to be affected by local chromatin environment.We surveyed a number of potential regulatory factors and observed that histone H3-H4 chaperon Asf1 contributed to parental histone recycling,while the eukaryotic replisome-associated components Mcm2 and Dpb3 displayed compounding effects in this process.In addition,the FACT complex also plays a role in the recycling of parental histones and helps to stabilize the nucleosomes.展开更多
文摘A solid acid catalyst has been prepared by grafting Boron trifluoride on mesoporous molecular sieve MCM 41 and characterized by XRD and FTIR techniques. The XRD and FTIR results indicated that the BF 3·Et 2O interlocks with the silicon groups of MCM 41 surface to form strong solid acid. The solid acid catalyst would effectively promote the opening of epichlorohydrin with isobutanol to form 1 isobutoxy 3 chloropropanol, and showed a nice activity and selectivity.
基金supported by the National Key Research and Development Program of China(2019YFA0508900)the National Natural Science Foundation of China(32170608,32288102)+1 种基金the K.C.Wong Educational Foundation(GJTD-2020-06)supported by the Youth Innovation Promotion Association(2017133,2020097)of the Chinese Academy of Sciences。
文摘Epigenetic information carried by histone modifications not only reflects the state of gene expression,but also participates in the maintenance of chromatin states and the regulation of gene expression.Recycling of parental histones to daughter chromatin after DNA replication is vital to mitotic inheritance of epigenetic information and the maintenance of cell identity,because the locus-specific modifications of the parental histones need to be maintained.To assess the precision of parental histone recycling,we developed a synthetic local label-chasing system in budding yeast Saccharomyces cerevisiae.Using this system,we observed that parental histone H3 can be recycled to their original position,thereby recovering their position information after DNA replication at all tested loci,including heterochromatin boundary,non-transcribed region,and actively transcribed regions.Moreover,the recycling rate appears to be affected by local chromatin environment.We surveyed a number of potential regulatory factors and observed that histone H3-H4 chaperon Asf1 contributed to parental histone recycling,while the eukaryotic replisome-associated components Mcm2 and Dpb3 displayed compounding effects in this process.In addition,the FACT complex also plays a role in the recycling of parental histones and helps to stabilize the nucleosomes.
