Atomically Precise Metal Nanoclusters as Single Electron Transferers for Hydroborylation

The emergence of metal nanoclusters with atomically precise compositions and structures provides an opportunity for in-depth investigation of catalysis mechanisms and structure−property correlations at the nanoscale.However,a serious problem for metal nanocluster catalysts is that the ligands inhibit the catalytic activity through deactivating the surface of the nanoclusters.Here,we introduce a novel catalytic mode for metal nanoclusters,in which the nanoclusters initiate the catalysis via single electron transfer(SET)without destroying the integrity of nanoclusters,providing a solution for the contradiction between activity and stability of metal nanoclusters.We illustrated that the novel activation mode featured low catalyst loading(0.01 mol%),high TOF,mild reaction conditions,and easy recycling of catalyst in alkyne hydroborylation,which often suffered from poor selectivity,low functional group tolerance,etc.Furthermore,the catalyst[Au_(1)Cu_(14)(TBBT)_(12)(PPh_(3))_(6)]^(+)(TBBTH:p-tert-butylthiophenol)can be applied in highly efficient tandem processes such as hydroborylation−deuteration and hydroborylation−isomerization,demonstrating the utility of the introduced activation mode for metal nanoclusters.

温阳补肾灸对血管性痴呆大鼠NF-κB信号通路的影响（英文）

目的:观察温阳补肾灸对血管性痴呆(VD)大鼠行为学、海马IL-1β、TNF-α及NF-κB相关基因与蛋白表达的影响,探讨温阳补肾灸抑制VD炎性反应的机制。方法:SD大鼠随机分为假手术组、模型组、艾灸组、西药组,每组10只。采用双侧颈总动脉缺血再灌注法制造VD大鼠模型。造模后,艾灸组大鼠悬灸"大椎""命门""关元",每次15 min,每日一次,连续治疗4周;西药组大鼠用尼莫地平灌胃(2 mg·kg^(-1)·d^(-1))连续治疗4周。运用Morris水迷宫测试对各组大鼠进行行为学检测。用HE染色观察其组织病理学改变。运用RT-qPCR法和Westernblot法检测海马IL-1β、TNF-α及NF-κB相关蛋白与基因的表达。结果:造模后手术组大鼠Morris水迷宫逃避潜伏期较假手术组明显延长(P<0.05)。HE染色显示模型组神经元细胞排列松散,细胞膜模糊,细胞质不均匀,核固缩,坏死量增多,炎细胞显著增加。与模型组相比,艾灸组与西药组炎细胞数目明显减少,神经元坏死减少。治疗后,与模型组比较,艾灸组、西药组大鼠海马组织TNF-α、p-IκB、NF-κBp65蛋白表达量显著降低(P<0.05);与模型组比较,艾灸组、西药组大鼠海马组织IL-1β、TNF-α、NF-κBp65 mRNA表达显著降低(P<0.05)。结论:温阳补肾灸可能通过降低脑内IL-1β、TNF-α及NF-κB相关基因的表达水平,抑制NF-κB信号通路,降低炎性反应,以达到治疗VD的目的。