饲喂不同浓度黄曲霉毒素B_1饲料对异育银鲫成鱼的生长和毒素积累的影响

以含不同浓度黄曲霉毒素B1(AFB1)的配合饲料饲喂异育银鲫(Carassius auratus gibelio)成鱼56d,研究异育银鲫成鱼[(122.3±0.7)g]生长、生理反应、肝脏组织学变化、卵巢发育以及鱼体各组织中的AFB1的毒素积累状况。实验分为5个实验组,不同实验组饲料中AFB1含量分别为0、5、20、50、500μg/kg饲料(实测值分别为2.59、4.12、12.39、46.23、454.07μg/kg饲料),每个处理3个平行。在整个实验过程中各实验组均未表现出外部形态和行为异常,各组存活率均达到100%。各实验组异育银鲫成鱼终末体重、摄食率(FR)、特定生长率(SGR)和饲料效率(FE)均无显著差异。饲料AFB1水平对异育银鲫血清总胆固醇(TC)含量、血清谷丙转氨酶(GPT)、谷草转氨酶(GOT)和碱性磷酸酶(AKP)活性均无显著影响。各毒素组血清超氧化物岐化酶(SOD)活性与对照无显著差异。各毒素组肝脏和卵巢均未见明显的组织学病理变化。肌肉和性腺中的AFB1积累量低于FDA食品安全限定标准(5μg/kg)。肝胰脏中的AFB1积累和饲料中的AFB1水平呈对数关系。饲喂AFB1≥50μg/kg饲料使异育银鲫成鱼肝脏AFB1积累超过安全限量标准。结果表明,异育银鲫成鱼至少可耐受AFB1含量达500μg/kg饲料(实测值:454.07μg/kg饲料)56d

Preparation and Characterization of TiO_2 Nanotubes Array by Anodic Oxidation in Anionic Modified Glycerol-Based Electrolyte

本文采用电化学阳极氧化法以含氟的甘油和水混合溶液为电解液在纯钛表面制备了一层排列规整的TIO2纳米管阵列,研究了电解液中额外添加3种2价阴离子、不同的电解时间及不同的添加物浓度等因素对所获得的TIO2纳米管阵列形貌的影响。结果表明,在改性电解液中制备的TIO2纳米管阵列的长度均超过了未改性的电解液中制备的,并随着氧化时间的增长,纳米管管口直径增大,管壁变薄;同时添加的(nH4)2TIf6浓度在0.025~0.1 MOl.l-1范围内均可获得管长更长且形貌较好的TIO2纳米管阵列。High-order TiO2 nanotube arrays on titanium foils were prepared in glycerol-based electrolyte containing fluorine and water by electrochemical anodic oxidation in this work.The influence of different dianion additives,different oxidation duration and concentration of electrolyte additives on the effect of the morphology of TiO2 nanotube arrays were investigated.Results showed that the length of TiO2 nanotube arrays in the modified electrolyte were longer than the samples in the unmodified electrolyte.And with the growth of oxidation duration,the diameter of the nanotubes increased,the wall were thinner;moreover better and longer TiO2 nanotube arrays can be prepared in the glycerol-based electrolyte with the range of the concentration of(NH4)2TiF6.国家自然科学基金(No.30970887;30600149); 卫生部科学研究基金(No.WKJ2008-02-037); 福建省杰青项目(No.2011J06019); 教育部重点项目(No.209061); 福建省纳米材料重点实验室科学基金(No.NM10-03)资助项

ERK干扰质粒的构建及对胃癌细胞株BGC823 DcR3表达的影响

目的探讨胃癌发展的分子机制,通过构建ERK1/2shRNA真核表达载体,体外研究其对人胃癌细胞株BGC823ERK1/2蛋白及DcR3表达水平的影响。方法应用PRNAT-U6.1/Neo载体构建ERK1/2基因shRNA重组质粒,经脂质体法导入BGC823细胞中,分别设置对照组、干扰组和U0126抑制剂组。Westernblot法检测转染后BGC823细胞及抑制剂使用后ERK1/2蛋白的表达变化,荧光显微镜检测质粒自带GFP基因的表达情况确认转染效率,ELISA法检测各组细胞上清中DcR3分泌蛋白的表达特点。结果成功构建ERK1/2基因shRNA重组质粒。证明了ERK1/2蛋白的表达与DcR3的分泌水平在BGC823细胞株中呈正相关。结论 ERK1/2干扰质粒明显降低BGC823细胞的ERK1/2蛋白表达水平,ERK信号通路对DcR3的分泌具有重要调控作用,为其下游调控机制的研究奠定了基础

肝癌发展中FasL及其受体Fas/DcR3的表达分析

目的研究小鼠肿瘤发生早期肿瘤坏死因子超家族成员FasL及其受体的表达特点,及其与免疫调节相关分子表达的时空关系,探讨其在诱导肿瘤免疫耐受中的作用。方法建立小鼠实体瘤模型,采用RT-PCR方法检测肿瘤组织中可溶型FasL、Fas及DcR3、TGF-β、IL-10在肿瘤发生不同时相的表达,同时,应用ELISA方法定量检测血清中TGF-β、IL-10的表达。结果在早期的肿瘤组织中,Fas的表达先于DcR3,其后DcR3大量表达,而Fas的表达则下调直至丢失,DcR3、FasL同时表达并上调,TGF-β和IL-10也随肿瘤的表达而上调。TGF-β同DcR3的表达具有空间位置的一致性。FasL、DcR3、TGF-β和IL-10的表达水平同肿瘤的生长呈正相关。结论随着肿瘤不断的生长,肿瘤局部的免疫应答逐渐趋向于负调节,FasL、DcR3在诱导肿瘤免疫耐受的过程中可能发挥着重要作用

Determination of Lead Content in Standard Materials of Lake Sediment and Tea by ID-ICP-MS

采用2种微波消解体系(HNO3-H2O2和HNO3-H2O2-HF)及3种定量模式(同位素稀释法、标准工作曲线法和标准加入法),对沉积物和茶叶标准物质中的铅进行测定,结果表明:同位素稀释质谱法的各项检测指标显著优于其它两种定量模式(茶叶中铅含量测定值为4.30μg/g),标准加入法次之(3.75μg/g),标准工作曲线法较差(3.61μg/g)。二种微波消解体系中,加HF酸优于不加HF酸,不加HF,茶叶中铅的回收率仅有89%,加入HF则上升为98%。Three different quantitative modes,namely external calibration,standard addition and isotope diluˉtion were compared for the determination of lead contents in lake sediment and tea standard materials with two digestion systems.The results showed that the isotope dilution gave the highest accuracy and precision in comˉparison with the other two modes.But the results were affected by the digestion system.For example,the reˉcoveries of lead content for tea were98%and89%for HNO 3 -H 2 O 2 -HF and HNO 3 -H 2 O 2 digesting sysˉtem,respectively.福建省重大科技项目子课题(2003Y005-04);; 厦门大学现代分析科学教育部重点实验室开放课题(B40402

分子对接预测H5亚型禽流感病毒的广谱中和表位

H5N1禽流感病毒已经在亚洲、欧洲和非洲广泛传播,造成了巨大损失.最近我们鉴定出一株对多种来源的H5N1代表株均有良好中和活性的、识别H5亚型血凝素(hemagglutinin,HA)的广谱单克隆抗体8H5,它对寻找克服禽流感高变性的广谱治疗性抗体、疫苗和药物具有重要价值.本研究应用分子模拟技术,采用"典范结构"方法对8H5抗体Fab片段进行结构模建,并通过能量分析、SAS值分析、"拉曼强传图"检验、profile-3D分析等理论验证,获得较为合理的8H5Fab的三维空间结构.8H5Fab与3种HA蛋白晶体结构的分子对接结果表明,8H5抗体与HA蛋白的作用模式与HA宿主来源无关,但与HA结构的亚型相似性相关.综合抗原同源比对结果,推测8H5抗体识别的广谱中和表位是由HA上的Asp68,Asn72,Glu112,Lys113,Ile114,Pro118,Ser120,Tyr137,Tyr252不连续氨基酸残基组成的构象表位.这一模型将为H5亚型禽流感病毒广谱疫苗和治疗性药物的分子设计提供依据

Raman Spectroelectrochemical Study on Bioactive Molecules

本文概述了采用电化学现场拉曼光谱技术研究氧化物歧化酶在L 半胱氨酸修饰金电极表面的电子迁移反应以及腺嘌呤共存条件下超氧化物歧化酶在金电极表面的电子迁移反应和不同电位下银电极表面烟酰胺腺嘌呤二核苷酸的吸附等体系的反应吸附特性 .所得结果对于分析和研究生物活性分子电化学过程机理具有重要意义 .Electron?transfer reaction is known to be one of the key reactions for generating biological functions. Mechanism revelation at a molecular level of such kind reactions is to be very helpful for us to understand life essence. In fact, surface enhanced Raman scattering (SERS) is one of the most powerful tools for the study on metal?electrolyte and metal?vacuum interfaces since 1970's. Moreover, Raman spectroscopic study in enzymology has provided attractive results during last twenty?five years. For the study of electron?transfer reaction mechanism of some oxidoreductases and SERS of some other biological macromolecules, an electrochemical in situ Raman spectroscopic technique was established in author's lab and some research works have been done on it in the past two years. A brief review of these works is given in this paper. The electrochemical in situ Raman spectroscopic measurements were carried out using a Super LABRAM Raman spectrometer (Dilor, France) coupled with a CHI604A Electrochemical Analyzer (CH Instr., USA). A Teflon spectroelectrochemical cell with a quartz plate window was designed for the in situ measurements. The working electrode was pretreated with oxidation?reduction cycles for each measurement. The electrolyte solutions were purged with nitrogen prior to all measurements, and all the measurements were carried out under the nitrogen atmosphere. Copper, zinc superoxide dismutase (SOD) is an important oxidoreductase for organism metabolism. The established spectroelectrochemical technique was first used to characterize the cyclic voltammetric process of SOD at L?cysteine modified gold electrode as well as the process of electrochemical modification of L?cysteine molecules on a gold electrode. The obtained Raman spectra reveal that the L?cysteine modified gold electrode improves effectively the reversibility of electron?transfer reactions of SOD. Besides L?cysteine molecules, it was interesting that adenine was also an effective electron?transfer promoter for SOD at gold electrode. A strong peak at 355 cm -1 can be observed in the Raman spectrum of adenine molecules adsorbed on gold electrode. It was inferred that the peak maybe related to the chemical interaction between adenine molecules adsorbed and gold electrode surface. As shown in Fig.1, for the mixture of SOD and adenine at gold electrode under a polarization potential 55 mV (vs. SCE), both the characteristic Raman lines of SOD and adenine molecules appeared. Therefore it was reasonable to conclude that SOD and adenine molecules should be co?adsorbed on gold electrode surface under such a potential, which is slightly lower than the reduction peak potential of SOD on adenine?modified gold electrode. Moreover, two new peaks appeared remarkably at 445 cm -1 and 610 cm -1 are likely to be related to the active site of SOD. It suggests that the co?adsorption mechanism of SOD and adenine molecules on the gold electrode surface results in effective approaching of the active site of SOD to the electrode surface.作者联系地址：上海师范大学化学系!上海200234,上海师范大学化学系!上海200234,上海师范大学化学系!上海200234,上海师范大学化学系!上海200234,上海师范大学化学系!上海200234,上海师范大学化学系!上海200234Author's Address: Dept. of Chem., Shanghai Teachers Univ., Shanghai 200234,Chin

Electrocatalytic Oxidation of Formic Acid on Pd/Ni Heterostructured Catalyst

通过两步还原法制备了Pd/Ni双金属催化剂.由于金属Pd原子在先行还原的Ni纳米粒子表面的外延生长以及其在Ni表面及Pd表面生长表现出的吉布斯自由能差异，最终导致了异结构Pd/Ni纳米粒子的形成.高分辨电子透射显微镜结果证实了异结构的存在，然而X射线衍射测量表明Pd/Ni纳米粒子具有类似于Pd的面心立方结构.制备的Pd/Ni纳米粒子与同等条件下合成的Pd纳米粒子相比对甲酸氧化呈现了更高的电催化活性，而且电催化稳定性也要明显优于纯Pd纳米粒子，证明Pd/Ni双金属催化剂是可选的直接甲酸燃料电池阳极催化剂.双金属催化剂对甲酸氧化电催化活性和稳定性增强可能是Ni原子的修饰改变了Pd粒子表面配位不饱和原子的电子结构所致.A Pd/Ni bimetallic nanostructured electrocatalyst was fabricated via a two-step reduction route. Owing to an epitaxial growth of Pd atoms on the surface of Ni nanoparticles, heterostructured Pd/Ni nanocomposites were formed and verified by high resolution transmission electron microscopy combined with energy-dispersion X-ray spectroscopy. X-ray diffraction confirmed that the as-prepared Pd/Ni nanocomposites possessed a single face-centered-cubic (fcc) Pd structure, probably due to a weaker diffraction intensity of metallic Ni and/or overlapping by that of Pd. The intrinsic catalytic activity on the Pd/Ni is higher than that on the Pd. Moreover, the durability of formic acid oxidation on the Pd/Ni was much enhanced over the Pd nanoparticles. The change in electronic structure of the surface coordination unsaturated Pd atoms and the possible dissolution of Ni species from the Pd/Ni heterostructure may account for such an improved durability for formic acid oxidation.This work was supported by the National Basic Research Program of China (973 Program) (No. 2012CB932800), the Natural Science Foundation of China (No. 21073219), Shanghai Science and Technology Committee (No. 11DZ1200400) and the Knowledge Innovation Engineering of the CAS (No. 12406, 124091231).This work was supported by the National Basic Research Program of China (973 Program) (No. 2012CB932800), the Natural Science Foundation of China (No. 21073219), Shanghai Science and Technology Committee (No. 11DZ1200400) and the Knowledge Innovation Engineering of the CAS (No. 12406, 124091231).作者联系地址：1. 中国科学院上海高等研究院，上海 201210；2. 中国科学院研究生院，北京 100039Author's Address: 1. Shanghai Advanced Research Institute, Chinese Academy of Sciences CAS, Shanghai 201210, China; 2. Graduate School of the CAS, Beijing 100039, China通讯作者E-mail：[email protected] & [email protected]

关于“经济发展方式转变进程中的财税政策”的探讨(笔谈)

转变经济发展方式是当前中国的热门话题,而上海在城市发展中又肩负着率先转变的重要任务,在这一意义和背景下,2010年4月24日由上海金融学院学院主办、上海金融学院公共经济管理学院承办的“《中国城市财政发展报告2009/2010:促进‘两个中心’建设的上海城市财政》首发式暨‘经济发展方式转变进程中的财税政策’论坛“在我校举行。与会专家围绕经济发展方式转变进程中的财税政策的“趋势与目标“、“机遇和挑战“、“实施方略“和“地方实践“等四个专题进行研讨,各抒己见,智慧交锋。现将其真知灼见整理摘要与读者分享,以期待更多学者共同关注当前经济发展方式转变进程中的财税政策