SYNTHESIS AND CRYSTAL-STRUCTURES OF THE BIMETALLIC RARE-EARTH COMPLEXES AND STUDIES ON INSERTION MECHANISM OF DIENES POLYMERIZATION

The deepening of the studies on essentials of rare earth coordination catalyst brings about more and more reports on model compounds as active centre of the catalyst. Among them the most significant researches are those with identification of the crystal structures of compounds.

A novel anti-tumor protein extracted from Meretrix meretrix Linnaeus induces cell death by increasing cell permeability and inhibiting tubulin polymerization

Discovery and development of new pharmaceuticals from marine organisms are attracting increasing interest. Several agents derived from marine organisms are under preclinical and clinical evaluation as potential anticancer drugs. We extracted and purified a novel anti-tumor protein from the coelomic fluid of Meretrix meretrix Linnaeus by ammonium sulphate fractionation, ion exchange and hydrophobic interaction chromatography. The molecular weight of the highly purified protein, designated MML, was 40 kDa as determined by SDS-PAGE analysis. MML exhibited significant cytotoxicity to several cancer cell types, including human hepatoma BEL-7402, human breast cancer MCF-7 and human colon cancer HCT116 cells. However, no inhibitory effect was found when treating murine normal fibroblasts NIH3T3 and benign human breast MCF-10A cells with MML. The cell death induced by MML was characterized by cell morphological changes. The induction of apoptosis of BEL-7402 cells by MML was weak by DNA ladder assay. The possible mechanisms of its anti-tumor effect might be the changes in cell membrane permeability and inhibition of tubulin polymerization. MML may be developed as a novel, highly selective and effective anti-cancer drug.

Haematopoietic lineage cell-specific protein 1 (HS1) promotes actin-related protein (Arp) 2/3 complex-mediated actin polymerization

HS1 (haematopoietic lineage cell-specific gene protein 1), a prominent substrate of intracellular protein tyrosine kinases in haematopoietic cells, is implicated in the immune response to extracellular stimuli and in cell differentiation induced by cytokines. Although HS1 contains a 37-amino acid tandem repeat motif and a C-terminal Src homology 3 domain and is closely related to the cortical-actin-associated protein cortactin, it lacks the fourth repeat that has been shown to be essential for cortactin binding to filamentous actin (F-actin). In this study, we examined the possible role of HS1 in the regulation of the actin cytoskeleton. Immunofluorescent staining demonstrated that HS1 co-localizes in the cytoplasm of cells with actin-related protein (Arp) 2/3 complex, the primary component of the cellular machinery responsible for de novo actin assembly. Furthermore, recombinant HS1 binds directly to Arp2/3 complex with an equilibrium dissociation constant (K-d) of 880 nM. Although HS1 is a modest F-actin-binding protein with a Kd of 400 nM, it increases the rate of the actin assembly mediated by Arp2/3 complex, and promotes the formation of branched actin filaments induced by Arp2/3 complex and a constitutively activated peptide of N-WASP (neural Wiskott-Aldrich syndrome protein). Our data suggest that HS1, like cortactin, plays an important role in the modulation of actin assembly.

The Key Factors In Fabrication Of High-Quality Ordered Macroporous Copper Film

The template-directed fabrication of highly-ordered porous film is of significant importance in implementation of the photonic band gap structure. The paper reports a simple and effective method to improve the electrodeposition of metal porous film by utilizing highly-ordered polystyrene spheres (PSs) template. By surface-modification method, the hydrophobic property of the PSs template surfaces was changed into hydrophilic one. It was demonstrated that the surface modi. cation process enhanced the permeability of the electrolyte solution in the nanometer-sized voids of the colloidal template. The homogeneously deposited copper film with the highly-ordered voids in size of less than 500 nm was successfully obtained. In addition, it was found that large defects, such as microcracks in the template, strongly influenced the macroporous films quality. An obvious preferential growth in the cracked area was observed. (C) 2008 Elsevier B. V. All rights reserved.

飞秒激光微加工：激光精密加工领域的新前沿

飞秒激光微加工技术具有加工精度高、热效应小、损伤阈值低以及能够实现真正的三维微结构加工等优点,这些特性是传统的激光加工技术所无法取代的。首先回顾了激光微加工和超短脉冲激光技术的发展历史,然后介绍超短脉冲激光与金属和介质材料相互作用的机制,接着阐述了飞秒激光直写、干涉和投影制备等各种加工方法的原理,重点讨论飞秒激光在三维光子器件集成、微流体芯片制备及其在生化传感方面的应用等,最后展望了飞秒激光微加工领域所面临的机遇和挑战,指出了未来的研究方向。

光致聚合物中单体及粘结剂对全息性能的影响

研究了单体及粘结剂等成份对全息光致聚合物薄膜光存储性能的影响。在相同引发条件下．以丙烯酰胺作为单体时，光聚物的衍射效率明显高于以丙烯酸和N羟甲基丙烯酰胺作为单体时光聚物的衍射效率。向丙烯酰胺中加入少量N-羟甲基丙烯酰胺，可以改善膜表面的光学质量．降低散射光强度，并提高膜的保存时间。在聚乙烯醇膜中单体聚合程度明显优于在聚乙烯吡咯烷酮中的程度，在大分子量的聚乙烯醇中的衍射效率及感光灵敏度高于在小分子量中的衍射效率和感光灵敏度，而且大分子量的聚乙烯醇能够制备厚膜，这是实现全息海量存储的一个重要因素。

Spectroscopic and structural properties of YbF3-doped fluorophosphate glasses

Compositional influences on the spectroscopic properties of Yb3+ and the structural variations with the introduction of YbF3 were studied in fluorophosphate glasses. Emission cross-section (sigma(emi)) and gain coefficient (sigma(emi) x tau(f)) were calculated which exhibit maximum at RF2 = 33 mol%. YbF3 has an important effect on the glass forming ability of fluorophosphate glasses when RF2 is over 36 mol%. The study of Raman spectra showed big differences on the glass structure between non-Yb3+ and Yb3+ -doped glasses. The main building units in Yb3+-doped samples are metaphosphate groups, pyrophosphate groups (P-2(O,F)(7), PO3F), Al[F-6] +Al[O,F](6) and F3Al-O-AlF3 while those of the non-Yb3+-doped glasses are monophosphate group P(O,F)(4), little pyrophosphate group, Al[F-4] + Al[F-6] + Al[O,F](4) + Al[O,F](6) and F3Al-O-AlF3, which means Yb3+ ions contribute to a better glass polymerization and network uniformity. (C) 2004 Elsevier B.V. All rights reserved.

Special effects of YbF3 on the structural changes for fluorophosphate glass

From Raman and IR spectra, obvious differences of the glass structure were observed in non-Yb3+-doped and Yb3+ -doped fluorophosphate glasses. Results showed that Yb3+ ions can induce, in a better glass, polymerization and network uniformity. Compared with the monophosphate-mastered Yb3+-free glass, Yb3+-doped glass has a pyrophosphate environment. The main building blocks in Yb3+ -doped samples are metaphosphate groups, pyrophosphate groups (P-2(O,F)(7),PO3F), Al[F-6]+Al[O,F](6) and F3Al-O-AlF3 while those of the Yb3+ -free glasses are monophosphate groups P(O,F)(4), little pyrophosphate groups, Al[F-4]+Al[F-6]+Al[O,F](4)+Al[O,F](6) and F3Al-O-AlF3. The DSC analysis also showed a slight increase in crystallization stability. (c) 2005 Elsevier B.V. All rights reserved.

电子束蒸发镀膜速率控制

介绍了电子束蒸发镀膜速率控制的基本原理和方法,选取实际生产中大量使用且蒸发特性较难控制的SiO_2和HfO_2,对两者的电子束蒸发速率控制分别进行了实验研究。采用比例积分微分(PID)闭环反馈控制,通过Ziegler-Nichols工程经验公式进行原始参量整定,并在实验的基础上对控制器的原始参量进行调整以及对积分作用和微分作用进行分区处理,速率控制的实验结果表明,采用该参量整定方法并结合工艺流程的改进,能获得良好的速率控制。针对速率控制中存在的难点问题进行了分析,并提出改进措施:将速率控制和电子枪扫描控制相结合能进一步改善速率控制。

Extraction of genomic DNA using a new amino silica monolithic column

A new amino silica monolithic column was developed for DNA extraction in a miniaturized format. The monolithic column was prepared in situ by polymerization of tetraethoxysilane (TEOS) and N-(beta-aminoethyl)-gamma-aminopropylmethyldimethoxysilane (AEAPMDMS). DNA was loaded in 50 mM tris(hydroxylmethyl)aminomethane-EDTA buffer at pH 7.0 and eluted with 300 mM potassium phosphate solution at pH 10.0. Under optimal condition, a 6.0-cm monolithic column provided a capacity of 56 ng DNA with an extraction efficiency of 71 +/- 5.2% (X +/- RSD). When the amino silica monolithic column was applied to extract genomic DNA from the whole blood of crucian carp, an extraction efficiency of 52 +/- 5.6% (X +/- SD) was obtained by three extractions. Since the chaotropic-based sample loading and organic solvent wash steps were avoided in this procedure, the purified DNA was suitable for downstream processes such as PCR. This amino silica monolithic column was demonstrated to allow rapid and efficient DNA purification in microscale.

Effects of cell-cycle arrest agents on cleavage and development of loach (Misgurnus anguillicaudatus) embryos

The aim of this study was to determine the lowest concentration of nocodazole and colchicine to arrest blastomere division during the cleavage stage of loach embryos and to assess the reversibility and toxicity of the treatments in the treated embryos. Eight-cell loach embryos were incubated for 4, 8, 12, or 16 h in 1/10x Holtfreter supplemented with either nocodazole, an inhibitor of tubulin polymerization, or colchicine, an inhibitor of tubulin assembly. Complete arrest of cell cycle was observed, at a colchicine concentration of 0.996 mM and at a nocodazole concentration of 0.275 muM, respectively (the lowest effective concentration). No major morphological alteration in chromatin was observed. Reversibility and toxicity of both agents were dose and exposure period dependent. For both agents, prolonging cleavage arrest for more than 4 h (at the effective concentrations) is detrimental to development of embryos. Nocodazole treatment was less cytotoxic, whereas the concentrations of colchicine which induce cleavage arrest were detrimental to development beyond the blastula stage. Toxic effects beyond the blastula stage could be minimized for both agents by reducing the period of treatment and concentration.