一种新型高价锰取代的多金属氧酸盐合成、结构及性质研究

在含有MnⅡ的夹心型多金属氧酸盐水溶液中加入强氧化剂KMnO4,制得一种新型的含有MnⅢ的多金属氧酸盐K5Na3[{MnⅢ(H2O)}2(WO)(H2O) (AsW9O33)2]·18H2O (KNa-1).该化合物的多阴离子结构是基于2个B-α-[AsW9]三缺位Keggin型构筑单元,中间夹着2个{MnⅢ(H2O)}和1个{WⅥO}片段而构成的夹心式构型.对KNa-1进行了变温磁化率测定并采用双核MnⅢ簇为模型进行了拟合,并对该化合物进行了电化学分析.结果表明:KNa-1 中的2个MnⅢ中心存在弱的反铁磁相互作用;化合物中的MnⅢ离子具有不可逆的氧化还原过程.     

Retinoblastoma family proteins: insights gained through genetic manipulation of mice

The retinoblastoma (Rb) gene was identified as the first tumor suppressor gene two decades ago. Since this initial discovery, it has become clear that deregulated Rb function constitutes a hallmark of human malignancies. Rb is a well-established regulator of the cell cycle. Rb has also been implicated in playing a role in a wide variety of cellular processes including DNA repair, cellular senescence, cell fate determination and apoptosis. Animals lacking Rb and/or its family members p107 and p130 have led scientists to uncover new and exciting roles for this protein family in development as well as tumor suppression. The ability to ablate Rb in a temporal and cell-type-specific manner has offered further, often unexpected, insights into Rb function. This review summarizes the phenotypic consequences of Rb family ablation in mice, and discusses how these findings contribute to the increasingly complex picture of Rb family function in development and tumor suppression. Received 11 October 2005; received after revision 16 November 2005; accepted 28 November 2005