铜在铜蛋白azurin分子构象及其促口腔肿瘤细胞凋亡中的作用

为了解铜对铜蓝蛋白azurin的构象和细胞毒性的影响,用重组表达的azurin作为研究材料,对结合铜的holo-azurin和除去铜的apo-azurin采用紫外、荧光和圆二色光谱进行了对比研究,其特征性变化为:去除铜离子后,该蛋白的紫外吸收光谱在628 nm的吸收峰消失,圆二色光谱出现轻微改变.采用两株p53呈阳性表达的中国人口腔癌细胞株Acc2和Acc3为研究对象,经四唑盐(MTT)比色法和流式细胞仪分析发现,azurin具有抑制上述肿瘤细胞株的生长,并促进肿瘤细胞凋亡的作用,而脱铜后的apo-azurin抗肿瘤活性降低.     

海洋微藻产生的不同粒级溶解有机物质的三维荧光光谱

通过过滤(0.7μm)和切向超滤(100kDa、10kDa、1kDa)技术将实验室内培养的赤潮异弯藻和中肋骨条藻藻液分离成100kDa-0.7μm、10～100kDa、1～10kDa的胶体浓缩液和＜1kDa的超滤液,利用激发-发射矩阵荧光光谱技术测定了不同粒级溶液中有机物的荧光性质,分析了三维荧光光谱图中的荧光峰位置、数量及荧光强度的变化情况.结果表明,两种微藻产生的类腐殖质荧光物质主要是＜1kDa的小分子物质.赤潮异湾藻产生的类蛋白荧光物质中,15%是100kDa-0.7μm的大胶体,8%是10～100kDa的中胶体,而大部分是＜1kDa的小分子物质.赤潮异弯藻各级超滤截留液的类蛋白荧光峰的发射波长与过滤液相比,发生蓝移,而超滤液的则发生红移,表明赤潮异湾藻产生的类蛋白荧光物质随着粒径的增大极性减弱.     

藻红蛋白含量可见光吸收光谱的测量

藻红蛋白(Phycoerythrin,PE)是衡量水体中藻类富营养化的一个重要指标,可见光吸收法具有测量快速、准确、无二次污染、可实现在线和原位测量等优点。因此,本文提出采用可见光吸收法测定水中藻红蛋白含量。以藻红蛋白标准液为研究对象,采集5~250 mg/L不同浓度标准液的可见光吸收光谱,对藻红蛋白进行定性定量分析。同时,对光谱的不同谱区预处理后,运用偏最小二乘法(PLS)建立可见光吸收光谱下的藻红蛋白校正分析模型,并与主成分回归法(PCR)进行比较。实验结果表明,采用PLS算法在谱区480~570 nm建立的校正分析模型的相关系数R2可达0.993,校正标准差RMSEC与相对标准差RSD最小,分别为5.578 3和3.92%。     

海洋浮游植物生长过程中溶解有机物质的三维荧光光谱研究

利用三维激发-发射矩阵荧光光谱技术,监测了赤潮异弯藻和中肋骨条藻培养过程中产生的溶解有机物,分析了三维荧光光谱图中的荧光峰位置、数量及荧光强度的变化情况.结果表明,微藻生长过程中会产生类蛋白和类腐殖质两类荧光有机物质,这两类有机物的荧光峰的位置及荧光强度有较大差异.在不同生长期,两类荧光有机物的产生机制不同.在指数生长期,两类有机物的荧光强度与藻密度成正相关,说明浮游植物释放了一定量的荧光物质;在平稳期和衰亡期,两类有机物的荧光强度迅速增加,这可能由于衰老、死亡藻细胞的破碎释放出大量的荧光有机物质所致,此外细菌对非荧光有机物进一步降解,也可能是产生该现象的一个原因.     

羟基磷灰石纳米颗粒诱导巨噬细胞凋亡及其与HSP70相互关系的研究

研究羟基磷灰石纳米颗粒(HAp nanoparticles)引起巨噬细胞凋亡,及其与热休克蛋白Hsp70的相关性.THP-1单核细胞株经PMA诱导成为巨噬细胞,分别加入0、20、100μg/ml HAp纳米颗粒,培养24h后经PI和AnexinV染色,在荧光显微镜下观察,用流式细胞仪检测细胞的凋亡情况,应用western blot 方法检测Hsp70蛋白分子表达的改变.显微镜观察显示THP-1单核细胞株能被诱导成巨噬细胞.荧光显微镜显示20、100μg/ml HAp纳米颗粒组凋亡的阳性信号明显强于0μg/ml对照组;流式细胞仪检测结果也证实HAp纳米颗粒组比对照组凋亡率明显增高(P1＜0.0001,P2＜0.0001),且凋亡的程度呈浓度依赖性(P3=0.025).Western Blot 检测显示20、100μg/ml HAp纳米颗粒组较对照组Hsp70蛋白表达增加,并且随颗粒浓度增高而表达增加.     

一种超支化共轭聚合物的合成与2,4-二硝基甲苯的荧光猝灭

以2,4,6-三甲基均三嗪和甲酰基咔唑、二甲酰基咔唑为原料,通过羟醛缩合反应合成了化合物I及超支化荧光共轭聚合物II,其中I可以视为II的组成单体。聚合物II在常见有机溶剂中有较好的溶解度,其X射线衍射谱图中2θ=24.2°的位置有1个较宽的峰;其吸收和荧光光谱与I的相比仅有轻微红移(3nm),这些结果都说明聚合物II分子间没有紧密的π-π堆积作用。聚合物II的荧光强度是化合物I的2倍。2,4-二硝基甲苯对其荧光猝灭研究结果表明,超支化聚合物II具有比化合物I更大的荧光猝灭常数(Ksv=95.52L/mol),表现出了一定的分子导线效应。     

含硅羟基磷灰石粉体的合成及其与蛋白质的相互作用研究

将硅掺入羟基磷灰石(HA)晶格中能有效地提高HA的生物相容性.采用湿法合成了含硅羟基磷灰石微粉(Si-HA),用X射线荧光光谱(XRF)、X射线衍射(XRD)、红外光谱(FTIR)、扫描电镜(TEM)和荧光光谱等对Si-HA的晶相、结构、化学组成、形貌及其与牛血清白蛋白(BSA)的相互作用进行了表征和分析.结果表明:Si元素溶入磷灰石晶格中,使HA晶胞参数和结构发生变化,随着Si含量的增加,HA中-OH和PO3-4的吸收峰呈减弱趋势,表明SiO4-4可能部分取代了PO3-4.Si-HA与BSA作用后的PO3-4吸收峰发生变化,在Si-HA图谱中出现了蛋白质的酰胺Ⅰ带和酰胺Ⅱ带吸收峰,随着Si-HA与BSA作用时间由2h～3d的变化,BSA溶液酰胺I带位置出现蓝移,半峰宽减小且峰型变得尖锐,酰胺II带则向低频区移动.Si-HA与BSA作用3d后,开始在1139处出现PO3-4的吸收峰.荧光光谱显示:加入相同质量的HA和Si-HA后蛋白质内源荧光强度较纯BSA溶液下降,随着Si-HA中Si质量分数的增加BSA荧光强度下降幅度增大,发射峰也出现红移,且Si-HA与BSA作用较纯HA与BSA的作用强,说明Si-HA使蛋白质二级结构发生改变,Si-HA中的Ca、PO3-4、SiO4-4与BSA之间发生了相互溶解、吸附和键合等作用,证明了Si-HA与生命物质蛋白质之间具有较高的反应性能,对Si-HA的生物活性及其与BSA相互作用的机理进行了详尽的阐述.     

羧基功能化聚苯乙烯荧光微球的制备及表征

以苯乙烯、丙烯酸为单体,引入疏水性荧光染料罗丹明6G(Rh6G),采用微乳聚合法制备羧基聚苯乙烯荧光微球,并分析了表面活性剂、引发剂、丙烯酸用量对产物粒径分布的影响,考察了羧基聚苯乙烯荧光微球的浓度对荧光强度的影响。通过粒度分析仪、扫描电子显微镜、红外光谱仪、紫外吸收光谱以及荧光光谱仪对样品的纳米特性、形貌、结构和荧光性能进行了表征。结果表明,用微乳聚合法制备出50~250nm的羧基聚苯乙烯荧光微球,粒径均一且呈单分散性。紫外光谱图测试表明,在533nm左右有吸收峰。荧光光谱测试表明,羧基功能化的荧光聚苯乙烯微球浓度≤0.01%,其荧光最大激发峰为527nm,最大发射峰在555nm处;浓度高于0.01%时,荧光光谱出现红移,且荧光强度减弱。     

亮绿与十二烷基苯磺酸钠褪色反应光谱特征初步研究

研究了亮绿与阴离子表面活性剂十二烷基苯磺酸钠的褪色反应.吸收光谱和荧光光谱表明,亮绿在溶液中有两种结构,一种是亮绿阳离子结构,在625nm有较强的吸收;另一种是醇结构,在428nm有较弱的吸收.亮绿阳离子结构不发荧光,而醇结构在430nm有较弱的荧光.625nm的吸收峰强度随反应时间呈线性减小,随反应温度先增加后减小,随溶液浓度增加而减弱,并且峰位发生红移.这可能是十二烷基苯磺酸钠对亮绿的静电效应和疏水效应引起的.通过高斯双峰拟合,亮绿在625nm的吸收峰可以拆分成两个,这两个吸收峰的吸光度随十二烷基苯磺酸钠浓度增加的变化程度基本一致,推测可能形成两种聚集体.     

牛奶中抗生素的液相芯片检测方法研究

利用悬液芯片系统建立了一种快速、多成份、高灵敏、高通量的抗生素残留的检测方法.使用表面具有羧基的微球作为固相载体,将人工合成的抗生素全抗原键合到微球上作为捕获抗原,与样品中的抗生素竞争体系中抗生素的单克隆抗体,使用藻红蛋白标记的二抗作为荧光探针,构建间接竞争反应体系.反应体系经悬液芯片系统可对荧光探针进行测定并对包被不同抗原的不同型号微球进行分类识别,实现抗生素的高通量检测.以检测牛奶中头孢氨苄、卡那霉素为例,头孢氨苄、卡那霉素的检测限分别为13.98 ng/mL、23.44 ng/mL,50%抑制的质量浓度(IC50)分别为56.88 ng/mL、190.09 ng/mL.     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.     

Low-Temperature Properties of Silver

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.     

Early ironwork in Biscay: Survey,excavation, experimentation and materials characterization. An integral study of the mountainside ironworks (ferrerías de monte or “haizeolak”)

ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.     

Mechanism Study on the Wear of CrAlTiN Coated High-Speed Steel Twist Drills Under Dry Cutting Conditions

As demands about environment protection are growing up, dry cutting technology is getting more and more concerns from all over the world. Main works performed here are study on dry cutting performances and wear mechanisms of M2high-speed steel (HSS) twist drills with CrAlTiN multicomponent coatings, which was deposited using magnetron sputter ion plating system, in drilling 45 and 30CrMnSiA steel, and their comparisons to those in drilling the same steel but using monolayer CrN and commercial TiN coated drills. Drilling performances of drills are evaluated mainly through the measurements of width on outer corner flank land and the cutting forces. Results show that performances of CrAlTiN coated drills are better than those of monolayer CrN and TiN coated drills. In drilling 45 and 30CrMnSiA steel, the average tool life of the CrAlTiN coated drills are 17.2 and 11.8 times higher than those of the uncoated drills. Observing wear of the drill with scanning electronic microscope, results show that there is no crack or spallation of the CrAlTiN coatings in wear zones. Main mechanism of the wear here is adhesion.     

Study on Bond Ability of Arc-Spraying Coatings with Different Surface Pretreatment on Cast-Iron

Arc spraying coatings are widely used in various applications, but uncommon in cast iron substrate. Different surface pretreatment technology is tested on substrates of gray cast iron. Surface roughness and residual stress were measured by TR200 and X-ray diffraction analyzer. Influence of different surface pretreatment methods ( dry blasting and fusebond) on roughness and residual stress was analyzed. The arc-sprayed coatings of wire 3Cr13 (φ2mm) on gray cast iron substrate is studied. The microstructure and interface of bonding layer were observed by SEM. The bond strength was taken by tensile test. Results show that bond strength with grit blasting is higher than fuse-bond; it is feasible to make wire 3Cr13 coating with arc spraying on cast iron substrate roughened by grit blasting.     

Structural Characteristics of TiO2 Ceramic Coating by Micro-Plasma Oxidation

TiO2 ceramic coatings with thickness of 20 μm were formed on the surface of pure titanium by micro-plasma oxidation. Their micro-structures were investigated by by using X-ray diffraction and their surface images were detected by using scan electronic microscope. There were three kinds of TiO2 coatings, pure anatase type TiO2 phase, mixed phases consisted of rutile type TiO2 phase and anatase type TiO2 phase, pure rutile type TiO2 phase. The coating surface with the pure anatase type TiO2 phase is rough, while the coating surface with the pure rutile type TiO2phase is smooth. The upper coating surface with the mixed type TiO2 phases is anatase type TiO2 structure and the subsurface of the TiO2 coating is rutile type TiO2structure.     

Evaluation of fatigue life of steel using steel grain size

The insightful discussion of the relationship between the construction of metallographic and fatigue life and proposition of mathematical relationships describing this relationship was conducted in the paper. This paper presents a method for estimating the fatigue life, based on the construction of the microstructural material taking into account the grain size and the participation of ferrite and pearlite phase.