A series of Poly(arly ether sulfone ether ketone)s containing pendant methyl groups were synthesized by the reaction of 4,4'-[sulfonylbis (1,4-phenylene)dioxy] dibenzoyl chloride (SODBC) with 4,4'- diphenoxy d...A series of Poly(arly ether sulfone ether ketone)s containing pendant methyl groups were synthesized by the reaction of 4,4'-[sulfonylbis (1,4-phenylene)dioxy] dibenzoyl chloride (SODBC) with 4,4'- diphenoxy diphenylsulfone (DPODPS), 4,4'- di(2-methylphenoxy) diphenylsulfone (o-Me-DPODPS), 4,4'- di(3-methylphenoxy) diphenylsulfone (m-Me-DPODPS), 4,4'- di (2,6-bimethylphenoxy) biphenylsulfone(o-Me2-DPODPS) respectively, in a mixture of 1,2-dichloroethane (DCE) and N-methylpyrrolidone (NMP). These reactions were catalyzed by anhydrous aluminum chloride (AlCl). The characteristic of copolymers were studied by means of advanced analytical techniques such as FT-IR,1H-NMR, DSC, TGA and WAXD. The results show glass transition temperature (Tg) in the range of 193-206℃, thermally stable in excess of 434℃ and excellent solubility in polar solvents. Methyl-substituted Poly(aryl ether sulfone ketone)s had higher glass transition temperatures, lower initial decomposition temperatures than the unsubstituted ones.展开更多
Mexico is a large producer of table grape (Vitis vinifera L.) and therefore it is important to develop protocols to store the grape varieties germplasm. The objective of the present work was to design a protocol for...Mexico is a large producer of table grape (Vitis vinifera L.) and therefore it is important to develop protocols to store the grape varieties germplasm. The objective of the present work was to design a protocol for the cryopreservation by vitrification of zygotic embryos of V. vinifera cv. "Red Globe" and evaluate possible epigenetics changes. The plant vitrification solution 2 (PVS2) was utilized before the utilization of liquid nitrogen (LN). The effect of this protocol on embryo viability was tested by the triphenyl-tetrazolium chloride solution, as well as by the in vitro development of grape embryos into plantlet. A cDNA expression library of grape zygotic embryos was created to isolate expressed sequence tags of several DNA methyltrasferases. Gene expression of domains rearranged methyltransferase type 1 (DMR1) and DNA (cytosine-5)-methyltransferase 1 (MET1-2) isozymes was analyzed by quantitative reverse transcriptase PCR. The optimal conditions for vitrification were 10 min in 50% PVS2, followed by I0 min in 100% PVS2. Under these conditions, about 30% of plantlet was obtained from embryos after cryopreservation. It was recorded a reduction in the MET1-2 gene expression, which plays a role in the maintenance of DNA methylation. It is possible to cryopreserve viable grape zygotic embryos, although the treatment seems to induce alterations in the normal DNA methylation pattern of the zygotic embryo genome.展开更多
We present the phase diagrams for neutral patchy colloidal particles whose surface is decorated by different number of identical patches,where each patch serves as an associating site.The hard-core Lennard-Jones(LJ)po...We present the phase diagrams for neutral patchy colloidal particles whose surface is decorated by different number of identical patches,where each patch serves as an associating site.The hard-core Lennard-Jones(LJ)potential and associating interaction are incorporated into the free energies of patchy particles in phases of the uid(F),random close packing(RCP),and face-centered-cubic(FCC)crystal.A rich phase structure of patchy particles with F-F,F-RCP,and F-FCC transitions can be observed.Meanwhile,the sol-gel transition(SGT)characterizing the connectivity of patchy particles is also investigated.It is shown that,depending on the number of patches and associating energy,the F-F transition might be metastable or stable with respect to the F-RCP and F-FCC transitions.Meanwhile,the critical temperatures,critical densities,triple points,and SGT can be significantly regulated by these factors.展开更多
基金This work was supported by National Science Foundation of China (No. 20264001 ), National Science Foundation of Jiangxi Province, Innovation Fund for Technology Based Firms of China (No. 06C26213601342).
文摘A series of Poly(arly ether sulfone ether ketone)s containing pendant methyl groups were synthesized by the reaction of 4,4'-[sulfonylbis (1,4-phenylene)dioxy] dibenzoyl chloride (SODBC) with 4,4'- diphenoxy diphenylsulfone (DPODPS), 4,4'- di(2-methylphenoxy) diphenylsulfone (o-Me-DPODPS), 4,4'- di(3-methylphenoxy) diphenylsulfone (m-Me-DPODPS), 4,4'- di (2,6-bimethylphenoxy) biphenylsulfone(o-Me2-DPODPS) respectively, in a mixture of 1,2-dichloroethane (DCE) and N-methylpyrrolidone (NMP). These reactions were catalyzed by anhydrous aluminum chloride (AlCl). The characteristic of copolymers were studied by means of advanced analytical techniques such as FT-IR,1H-NMR, DSC, TGA and WAXD. The results show glass transition temperature (Tg) in the range of 193-206℃, thermally stable in excess of 434℃ and excellent solubility in polar solvents. Methyl-substituted Poly(aryl ether sulfone ketone)s had higher glass transition temperatures, lower initial decomposition temperatures than the unsubstituted ones.
文摘Mexico is a large producer of table grape (Vitis vinifera L.) and therefore it is important to develop protocols to store the grape varieties germplasm. The objective of the present work was to design a protocol for the cryopreservation by vitrification of zygotic embryos of V. vinifera cv. "Red Globe" and evaluate possible epigenetics changes. The plant vitrification solution 2 (PVS2) was utilized before the utilization of liquid nitrogen (LN). The effect of this protocol on embryo viability was tested by the triphenyl-tetrazolium chloride solution, as well as by the in vitro development of grape embryos into plantlet. A cDNA expression library of grape zygotic embryos was created to isolate expressed sequence tags of several DNA methyltrasferases. Gene expression of domains rearranged methyltransferase type 1 (DMR1) and DNA (cytosine-5)-methyltransferase 1 (MET1-2) isozymes was analyzed by quantitative reverse transcriptase PCR. The optimal conditions for vitrification were 10 min in 50% PVS2, followed by I0 min in 100% PVS2. Under these conditions, about 30% of plantlet was obtained from embryos after cryopreservation. It was recorded a reduction in the MET1-2 gene expression, which plays a role in the maintenance of DNA methylation. It is possible to cryopreserve viable grape zygotic embryos, although the treatment seems to induce alterations in the normal DNA methylation pattern of the zygotic embryo genome.
基金supported by the National Natural Science Foundation of China(No.21374028 and No.21306034)the Natural Science Foundation of Hebei Province(No.B2014201103)+2 种基金the Project for Talent Engineering of Hebei Province(No.A2016015001)the Project for Top Young Talent of Hebei Provincethe Project for Top Young Talent of General Colleges of Hebei Province(No.BJ2017017)
文摘We present the phase diagrams for neutral patchy colloidal particles whose surface is decorated by different number of identical patches,where each patch serves as an associating site.The hard-core Lennard-Jones(LJ)potential and associating interaction are incorporated into the free energies of patchy particles in phases of the uid(F),random close packing(RCP),and face-centered-cubic(FCC)crystal.A rich phase structure of patchy particles with F-F,F-RCP,and F-FCC transitions can be observed.Meanwhile,the sol-gel transition(SGT)characterizing the connectivity of patchy particles is also investigated.It is shown that,depending on the number of patches and associating energy,the F-F transition might be metastable or stable with respect to the F-RCP and F-FCC transitions.Meanwhile,the critical temperatures,critical densities,triple points,and SGT can be significantly regulated by these factors.