The twisted aromatics, functional dibenzo[d,f][1,3]dioxepine derivatives were synthesized in high yields from reactions of 5,5＇-dibromo-2,2＇-biphenol with corresponding ketal or ketone compounds under acid catalysis...The twisted aromatics, functional dibenzo[d,f][1,3]dioxepine derivatives were synthesized in high yields from reactions of 5,5＇-dibromo-2,2＇-biphenol with corresponding ketal or ketone compounds under acid catalysis. The structures of these compounds were characterized by ^1H NMR, elemental analysis, UV-Vis absorption spectrum and X-ray diffraction analysis. The conformation of O--C--O bridged biphenyl derivatives with varied substitute groups on 6,6＇-position was studied by X-ray crystallography and force-field simulation. The result of calculations by UNIVERSAL 1.02 force field in Cerius2 package（4.6） indicates that dibenzo[d,f][1,3]dioxepine derivatives show twisted conformations and the twisted angle between the phenyl rings is about 40°, which is accordant with the result from crystal structure determination, though the obtained angles in the crystal of dibenzo[d,f][1,3]dioxepine derivatives with the varied substitute groups on 6,6＇-position are shown to be slightly shifted to 40° owing to intermolecular interactions in crystal stacking. DSC studies exhibit that the substitute groups on 6,6＇-position can induce a large variation of endothermic peaks ranging from 80 to 135 ℃. The conjugated polymers based on dibenzo[d,f][1,3]dioxepine derivatives, which have ultraviolet emitting with a quantum efficiency of 10%, were obtained by Yamamoto coupling.展开更多
目的:探讨机械牵拉后人肺微血管内皮细胞(human pul monary microvascular endothelial cells,HPMVECs)单层通透性、F-肌动蛋白(F-actin)的变化及它们之间的关系,并探讨Rho激酶抑制剂Y27632对上述变化的影响。方法:体外培养HPMVECs,磁...目的:探讨机械牵拉后人肺微血管内皮细胞(human pul monary microvascular endothelial cells,HPMVECs)单层通透性、F-肌动蛋白(F-actin)的变化及它们之间的关系,并探讨Rho激酶抑制剂Y27632对上述变化的影响。方法:体外培养HPMVECs,磁扭力刺激(magnetic twisting sti mulation,MTS)实施机械牵拉,随机分为3组,对照组(C组):细胞不经MTS,在细胞培养箱中培养1h、2h;机械牵拉组(M组):MTS1h、2h;抑制剂组(Y组):细胞与Rho激酶抑制剂Y27632(10μmol/L)孵育2h后给予MTS1h、2h;用FITC标记的右旋糖苷在transwell模型中的通透率检测HPMVECs单层通透性,用免疫荧光染色检测HPMVECs的F-actin分布。结果:M组的HPMVECs单层通透性较C组显著增加(P<0.05),且MTS2h后HPMVECs单层通透性较MTS1h高(P<0.05);Y组则较M组显著降低(P<0.05)。C组细胞F-actin主要分布在细胞边缘;而MTS引起F-actin聚合形成应力纤维,而以刺激2h明显;而Y组应力纤维形成较M组明显减少。结论:机械牵拉可引起HPMVECs的单层通透性增高,F-actin聚集形成应力纤维,且HPMVECs单层通透性增高的机制可能与F-actin聚集成应力纤维密切相关。Y27632可通过抑制应力纤维形成而减轻机械牵拉对HPMVECs单层通透性的影响。展开更多
A useful reduction is presented to determine the finiteness of Δ -good module category F(Δ) of a quasi-hereditary algebra.As an application of the reduction, the F(Δ) -finiteness of quasihereditary M-twis...A useful reduction is presented to determine the finiteness of Δ -good module category F(Δ) of a quasi-hereditary algebra.As an application of the reduction, the F(Δ) -finiteness of quasihereditary M-twisted double incidence algebras of posets is discussed. In particular, a complete classification of F(Δ)- finite M-twisted double incidence algebras is given in case the posets are linearly ordered.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.20125421 and 90101026)the Ministry of Science and Technology of China(No.2002CB6134003)
文摘The twisted aromatics, functional dibenzo[d,f][1,3]dioxepine derivatives were synthesized in high yields from reactions of 5,5＇-dibromo-2,2＇-biphenol with corresponding ketal or ketone compounds under acid catalysis. The structures of these compounds were characterized by ^1H NMR, elemental analysis, UV-Vis absorption spectrum and X-ray diffraction analysis. The conformation of O--C--O bridged biphenyl derivatives with varied substitute groups on 6,6＇-position was studied by X-ray crystallography and force-field simulation. The result of calculations by UNIVERSAL 1.02 force field in Cerius2 package（4.6） indicates that dibenzo[d,f][1,3]dioxepine derivatives show twisted conformations and the twisted angle between the phenyl rings is about 40°, which is accordant with the result from crystal structure determination, though the obtained angles in the crystal of dibenzo[d,f][1,3]dioxepine derivatives with the varied substitute groups on 6,6＇-position are shown to be slightly shifted to 40° owing to intermolecular interactions in crystal stacking. DSC studies exhibit that the substitute groups on 6,6＇-position can induce a large variation of endothermic peaks ranging from 80 to 135 ℃. The conjugated polymers based on dibenzo[d,f][1,3]dioxepine derivatives, which have ultraviolet emitting with a quantum efficiency of 10%, were obtained by Yamamoto coupling.
文摘目的:探讨机械牵拉后人肺微血管内皮细胞(human pul monary microvascular endothelial cells,HPMVECs)单层通透性、F-肌动蛋白(F-actin)的变化及它们之间的关系,并探讨Rho激酶抑制剂Y27632对上述变化的影响。方法:体外培养HPMVECs,磁扭力刺激(magnetic twisting sti mulation,MTS)实施机械牵拉,随机分为3组,对照组(C组):细胞不经MTS,在细胞培养箱中培养1h、2h;机械牵拉组(M组):MTS1h、2h;抑制剂组(Y组):细胞与Rho激酶抑制剂Y27632(10μmol/L)孵育2h后给予MTS1h、2h;用FITC标记的右旋糖苷在transwell模型中的通透率检测HPMVECs单层通透性,用免疫荧光染色检测HPMVECs的F-actin分布。结果:M组的HPMVECs单层通透性较C组显著增加(P<0.05),且MTS2h后HPMVECs单层通透性较MTS1h高(P<0.05);Y组则较M组显著降低(P<0.05)。C组细胞F-actin主要分布在细胞边缘;而MTS引起F-actin聚合形成应力纤维,而以刺激2h明显;而Y组应力纤维形成较M组明显减少。结论:机械牵拉可引起HPMVECs的单层通透性增高,F-actin聚集形成应力纤维,且HPMVECs单层通透性增高的机制可能与F-actin聚集成应力纤维密切相关。Y27632可通过抑制应力纤维形成而减轻机械牵拉对HPMVECs单层通透性的影响。
文摘A useful reduction is presented to determine the finiteness of Δ -good module category F(Δ) of a quasi-hereditary algebra.As an application of the reduction, the F(Δ) -finiteness of quasihereditary M-twisted double incidence algebras of posets is discussed. In particular, a complete classification of F(Δ)- finite M-twisted double incidence algebras is given in case the posets are linearly ordered.
