毛细管电泳-柱端安培检测法用于抗癌药物2-氨基-6-巯基嘌呤和8-氮杂鸟嘌呤的研究

采用毛细管电泳-安培检测法建立一种简单、快速、有效的同时分析抗癌药物2-氨基-6-巯基嘌呤和8-氮杂鸟嘌呤的新方法.在长50 cm、内径为25μm的未涂层毛细管中,采用20 mmol/L磷酸盐(pH为7.0)缓冲液作为运行液,当分离电压为21 kV时,两组分在12 min内达到基线分离.在上述最佳分离条件下,当电极电位为1.050V、进样时间为10 s时,2-氨基-6-巯基嘌呤和8-氮杂鸟嘌呤的峰电流和浓度之间呈良好的线性关系,其相关系数分别为0.999 20、.999 0,检测限分别为3.0×10-7、2.0×10-7mol/L.7次重复实验2-氨基-6-巯基嘌呤和8-氮杂鸟嘌呤的日间峰电流RSD分别为2.44%3、.46%.利用该法检测了牛血清蛋白中的2-氨基-6-巯基嘌呤和8-氮杂鸟嘌呤,回收率分别为100%-113%,93.0-102%.     

BOUNDEDNESS OF FRACTIONAL INTEGRAL OPERATORS IN HERZ—TYPE SPACES ON LOCALLY COMPACT VILENKIN GROUPS

Let G be a locally compact Vilenkin group.In this paper we first establish the Hardy-Littlewood-Sobolev theorem on G.Then some boundedness theorems of fractional integral operators in Herz-type spaces on G are obtained.     

1-(2-羟甲基-1,3-氧硫杂环戊基)吡啶酮类化合物的合成

研究了1,3-氧硫杂环戊烷核苷类似物的合成. 以吡啶酮为碱基, 利用三甲基硅基三氟甲磺酸酯(TMSOTf)催化, 与1,3-氧硫杂环戊烷发生Vorbruggen缩合反应, 合成了一系列的保护的核苷类似物, 经过进一步脱保护或者还原得到目标产物. 并测试了合成化合物的抗菌活性, 发现该类化合物对革兰氏阳性菌具有中等抑制活性.     

Notes on piecewise-Koszul algebras

The relationships between piecewise-Koszul algebras and other “Koszul-type” algebras are discussed. The Yoneda-Ext algebra and the dual algebra of a piecewise-Koszul algebra are studied, and a sufficient condition for the dual algebra A ^! to be piecewise-Koszul is given. Finally, by studying the trivial extension algebras of the path algebras of Dynkin quivers in bipartite orientation, we give explicit constructions for piecewise-Koszul algebras with arbitrary “period” and piecewise-Koszul algebras with arbitrary “jump-degree”.     

还原氧化石墨烯/碳纳米管/Co_3O_4三元复合材料的制备与电化学性能

将低温水热反应和低温热处理相结合,制备了含还原氧化石墨烯(RGO)、碳纳米管(CNTs)和Co3O4的三元纳米复合材料RGO-CNTs-Co3O4;利用X射线衍射仪、扫描电子显微镜、透射电子显微镜分析了合成产物的相组成和微观结构,分析了其形成过程;并利用电化学测试装置测定了其作为锂离子电池负极材料的电化学性能.结果表明,在合成反应过程中,氧化石墨烯被还原剂肼还原为石墨烯,同时在石墨烯和CNTs表面生成氢氧化钴;再经低温热处理得到RGO-CNTs-Co3O4三元复合材料.Co3O4纳米颗粒均匀分散在由RGO片层和CNTs组成的三维网络结构中;这种三维网络结构既有利于电子和离子的传输,又能够有效抑制Co3O4在脱嵌锂过程中因体积变化引起的结构破坏.总体而言,合成的新型三元复合材料具有高的比容量以及良好的循环性能与倍率性能.     

Radical Addition Reactions of α-Substituted β,β-Difluorovinyl Sulfones

The radical addition reactions of α-substituted β,β-difluorovinyl sulfones 1 with α-oxy and acyl radical species, such as 1,3-dioxolane, tetrahydrofuran, 1,4-dioxane, butanal and hexanal, afforded radical addition products 2--16 in good yields.     

Kr/Xe气体在塑料闪烁体表面的吸附与扩散行为研究

采用基于Compass力场的分子动力学(MD)方法,研究了惰性气体氙(Xe)和氪(Kr)在塑料闪烁体(聚乙烯基对甲苯)的平整和粗糙表面的吸附和扩散行为.由惰性气体吸附曲线的均方根位移(MSD),得到了Xe/Kr气体在聚乙烯基对甲苯表面的扩散系数.研究结果表明,Kr/Xe气体均被稳定地吸附在塑料闪烁体表面,其稳定性随着温度的升高而增加,Xe分子的吸附性强于Kr分子. Kr/Xe气体在聚乙烯基对甲苯表面具有较强的扩散性能,扩散深度随着温度与厚度的增加而增加,最大为22.865?,Kr分子扩散能力强于Xe分子.基底粗糙表面增加了两种惰性气体分子的吸附和扩散.     

Palladium‐Catalyzed Asymmetric [8+2] Dipolar Cycloadditions of Vinyl Carbamates and Photogenerated Ketenes

Higher‐order cycloadditions, particularly [8+2] cycloadditions, are a straightforward and efficient strategy for constructing significant medium‐sized architectures. Typically, configuration‐restrained conjugated systems are utilized as 8π‐components for higher‐order concerted cycloadditions. However, for this reason, 10‐membered monocyclic skeletons have never been constructed via catalytic asymmetric [8+2] cycloaddition with high peri‐ and stereoselectivity. Here, we accomplished an enantioselective [8+2] dipolar cycloaddition via the merger of visible‐light activation and asymmetric palladium catalysis. This protocol provides a new route to 10‐membered monocyclic architectures bearing chiral quaternary stereocenters with high chemo‐, peri‐, and enantioselectivity. The success of this strategy relied on the facile in situ generation of Pd‐containing 1,8‐dipoles and their enantioselective trapping by ketene dipolarophiles, which were formed in situ via a photo‐Wolff rearrangement.     

卡维地洛印迹聚合物的合成及其识别性能的研究

以卡维地洛药物分子为模板,甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,采用紫外光引发聚合的分子印迹技术,成功制备出卡维地洛分子印迹聚合物。用热重分析、扫描电镜对聚合物进行了表征,通过Scatchard方程研究了印迹聚合物对模板分子的结合特性。结果表明,在所研究的浓度范围内,印迹聚合物存在一类等价的结合位点,并计算出印迹聚合物与模板分子的平衡离解常数为0.5642 mmol/L,最大表观吸附量为97.44μmol/g,为理论值的63.53%。对不同底物的结合实验表明,该聚合物对卡维地洛具有优良的吸附选择性。