Group Entwining Structures and Group Coalgebra Galois Extensions

Abstract

The notions of group coalgebra Galois extension and group entwining structure are defined. It is proved that any group coalgebra Galois extension induces a unique group-entwining map ψ = {ψ_{α, β}}_{α, β∈π} compatible with the right group coaction, generalizing the recent work of Brzeziński and Hajac [Brzeziński, T., Hajac, P. M. (1999). Coalgebra extensions and algebra coextensions of Galois type. Comm. Algebra 27:1347–1368].     

Petrographic, chemical and microprobe analysis of an oxidized iron nodule from Dahr Safra, NW Syria: Is it an iron ore, or a meteorite called shale-ball?

The iron nodule DS-S revealed the concentrations of Ni, Co, Ga, Ge, As, Sb, P, S, many trace and rare earth elements, Fe (> 93 wt.%), and 2 wt.% silicates. The plotting of Ga, Ge, Cr, Cu, As, Au, W, and Ir-concentrations vs. Ni/Co in the classes (groups) IIAB, IIIAB, IVA, ungrouped (ung), NBS 809B steel (st), and DS-S, confirmed the meteoritic origin for DS-S. Magnetite-hematite resulted from oxidation during the melting/solidification process of the original meteorite across the atmosphere. The silicates suggested the presence of Ca-rich plagioclase, and traces of opx, cpx, and/or olivine which explained the low concentrations of Ni-Co. The plotting of Ga/Ge vs. Ni/Co; Ni/Co, Ga vs. P; and Ni/Co, Ga/Ge vs. As revealed the affinity of the DS-S nodule with the ungrouped Bellsbank trio. The compositional homogeneity in the DS-S nodule was probably due to O-fugacity. The conformable REE-graphs, for chondrite and DS-S, and the presence of silicates with the same phases suggested a mesosideritic origin for DS-S.     

在结构化学教学中增设量子化学计算实验课的探索

结构化学是化学专业本科生的主干核心课程,对培养高水平人才具有重要作用。立足于学生兴趣和课程特点,本文提出在结构化学教学中增设量子化学计算实验课。紧扣教学大纲重难点,设计制作了4个基础实验,阐述了内容及实施细节。该改革让学生以计算机为仪器、应用结构化学知识来解决和理解化学问题,提升了学习兴趣和教学效果。     

The First Intramolecular Charge Transfer Transition Based on 2-Ureido-4[1H]-pyrimidinone Binding Module

The first intramolecular charge transfer transition based on 2-ureido-4[1H]-pyrimidinone binding module was reported.     

Structural insights of a cellobiose dehydrogenase enzyme from the basidiomycetes fungus Termitomyces clypeatus

Filamentous fungi secrete various oxidative enzymes to degrade the glycosidic bonds of polysaccharides. Cellobiose dehydrogenase (CDH) (E.C.1.1.99.18) is one of the important lignocellulose degrading enzymes produced by various filamentous fungi. It contains two stereo specific ligand binding domains, cytochrome and dehydrogenase - one for heme and the other for flavin adenine dinucleotide (FAD) respectively. The enzyme is of commercial importance for its use in amperometric biosensor, biofuel production, lactose determination in food, bioremediation etc. Termitomyces clypeatus, an edible fungus belonging to the basidiomycetes group, is a good producer of CDH. In this paper we have analyzed the structural properties of this enzyme from T. clypeatus and identified a distinct carbohydrate binding module (CBM) which is not present in most fungi belonging to the basidiomycetes group. In addition, the dehydrogenase domain of T. clypeatus CDH exhibited the absence of cellulose binding residues which is in contrast to the dehydrogenase domains of CDH of other basidiomycetes. Sequence analysis of cytochrome domain showed that the important residues of this domain were conserved like in other fungal CDHs. Phylogenetic tree, constructed using basidiomycetes and ascomycetes CDH sequences, has shown that very surprisingly the CDH from T. clypeatus, which is classified as a basidiomycetes fungus, is clustered with the ascomycetes group. A homology model of this protein has been constructed using the CDH enzyme of ascomycetes fungus Myricoccum thermophilum as a template since it has been found to be the best match sequence with T. clypeatus CDH. We also have modelled the protein with its substrate, cellobiose, which has helped us to identify the substrate interacting residues (L354, P606, T629, R631, Y649, N732, H733 and N781) localized within its dehydrogenase domain. Our computational investigation revealed for the first time the presence of all three domains - cytochrome, dehydrogenase and CBM - in the CDH of T. clypeatus, a basidiomycetes fungus. In addition to discovering the unique structural attributes of this enzyme from T. clypeatus, our study also discusses the possible phylogenetic status of this fungus.     

贝克曼AllegraTM21R型超高速离心机故障排除一例

贝克曼Allegra^TM 21R型超高速离心机开机后，操作面板上出现错误代码“28”，离心机不旋转。离心机的电机采用无刷感应驱动，由电机驱动电源模块BSMl0GD60DN2驱动离心机的电机。故障是由于电源模块BSMl0GD60DN2损坏引起的。采用东芝三相桥式IGBT电源模块MG25Q6ES42代替BSMl0GD60DN2，并更换已烧毁的栅极电阻后。开机试验，仪器恢复正常。     

基于结构的新型CDK7抑制剂的设计、合成及其抗肿瘤活性

根据细胞周期依赖性激酶7(CDK7)的蛋白结构, 利用Discovery Studio 2.1程序包中的LigandFit模块建立了CDK7抑制剂的分子对接模型, 采用受试者工作特征曲线(ROC)方法选择LigScore2为最佳打分函数(ROC曲线下的面积为0.95), 并验证了该模型的准确性. 利用该模型对设计的化合物与CDK7蛋白进行对接分析, 得到了2个打分最高的化合物16、17, 进而通过13步的合成路线, 以中等至高的收率得到目标化合物, 并测定其体外抗肿瘤活性. 结果表明, 所合成的化合物对急性前髓细胞性白血病细胞(HL60)、鼻咽癌细胞(KB)、肝肿瘤细胞(SMMC-7721)、结肠腺癌细胞(HCT-116)、肺癌细胞(A549)细胞株均有抑制作用(IC50值为0.84-19.70 μmol·L-1), 其中化合物16对HL60细胞株的IC50值最低, 为0.84 μmol·L-1.     

High performance polyethersulfone UF membrane for manufacturing spiral wound module: preparation,morphology, performance,and chemical cleaning

Large sheet asymmetric polyethersulfone (PES) ultrafiltration membranes were prepared via phase inversion process in a continuous conveyor system with addition of PVP to the casting solution. Dimethylacetamide (DMAc) and mixture of water and isopropyl alcohol (70/30 v%) were used as solvent and non‐solvent respectively. The prepared membrane was 0.96 m wide and 3 m long. The pieces of the membrane were selected randomly for characterization in terms of performance using cross flow filtration for milk concentration, image analysis, scanning electron microscopy (SEM), and cleaning procedures. It was found that the prepared membrane has high porosity and high water flux during milk filtration. In addition, cleaning experiments indicated that NaOH/HCl/NaOH sequence is an effective procedure for cleaning the fouled membrane during milk concentration. Copyright © 2007 John Wiley & Sons, Ltd.     

钙钛矿太阳能电池的商业化进展与挑战

钙钛矿太阳电池是一项颠覆性的光伏技术,具有能量转化效率高、生产成本低、制备工艺简单等优势。当前,钙钛矿太阳能电池的认证效率已达25.7%,但其面临着严重的商业化瓶颈,如稳定性差、模组效率相对低、铅毒性等,且这些问题相互关联。本文简述了钙钛矿太阳能电池的工作原理和器件结构,并归纳总结了在解决钙钛矿太阳能电池稳定性、封装和模组化等商业化瓶颈问题方面的主要研究进展。最后,本文提出了钙钛矿光伏商业化进程中值得关注的解决措施。     

结构DNA纳米技术应用新进展

DNA具有非凡的分子识别性能和显著的结构特征,这使得它在材料的纳米级调控方面具有独特的优越性,在许多领域也展现出广阔的应用前景。本文从模块化DNA自组装和DNA折纸术两个方面综述了近些年DNA纳米技术,包括近年来DNA纳米技术中比较新型的组装方法;并从DNA纳米结构作为模板定位纳米粒子和蛋白以及用于生物医药等方面介绍了DNA纳米技术的应用;同时,对DNA纳米技术发展及应用进行了展望。