纳米材料的生物安全性研究进展

概述了近年来国内外在纳米材料的生物安全性研究方面的工作,并介绍了4个主要研究方向,包括纳米材料在环境中的传播、纳米材料的尺寸和结构与其生物效应之间的关系研究、纳米材料与生物体相互作用机理研究以及纳米材料生物安全性评价体系的研究。最后对纳米材料生物安全性研究的发展前景提出了展望。     

生物体内硒蛋白的计算机识别方法

硒是人体必需的微量元素,在人体内主要形成硒蛋白。硒蛋白的计算机识别,不仅能预测生物体中硒的形态,而且可为硒的生化性质研究提供理论基础,以阐明硒的生物功能。本文以斑马鱼为研究对象,结合已有生物分析软件,采用PERL语言编程,建立了计算机识别硒蛋白的新方法。它根据硒蛋白基因的判断标准、以目前公布的不同物种的基因组注释信息为基础,将以TGA码终止的基因的再分析、3′-UTR区域中硒代半胱氨酸插入序列(SECIS)结构的检索、同源相似基因中硒代半胱氨酸/半胱氨酸的比对,以及硒蛋白基因编码区的识别等步骤,从已注释的基因组中用计算机寻找和鉴定硒蛋白的形态。当前,已有一些识别硒蛋白的方法,但只能识别专一物种,而本文提出的方法,克服了该缺陷,而且对计算机运算速度和容量无苛刻要求,尤其是发现不同物种新硒蛋白方面有优势。本方法普遍适用于不同物种基因组中,硒蛋白的计算机预测与识别。     

酶解泥鳅蛋白的毒理学评价(二)

２．２．２小鼠骨髓嗜多染红细胞微核实验结果见表３,受试物各剂量组雌雄性别微核形成率与阴性对照结果比较,差异无显著性,表明该受试物骨髓微核试验结果为阴性。２．２．３小鼠精子畸形试验结果见表４,各与阴性对照组结果比较,差异无显著性,表明该精子畸形试验结果为阴性。２．３喂养３０d试验２．３．１动物一般表现试验过程中动物无死亡,毛发正常,无异常行为表现。２．３．２对大鼠体重的影响从表５可见,受试物各组体重与阴性对照组结果比较,差异无显著性（P＞０．０５）,各组间差异也无显著性（P＞０．０５）。２．３．３酶…     

酶解泥鳅蛋白的毒理学评价(一)

采用常规毒理学评价方法研究了酶解泥鳅蛋白对两种性别的SPF级昆明种小鼠经口毒性.二次灌胃总量达12.0g/kg@bw,一周内动物未见明显中毒症状,无动物死亡,按急性毒性分级标准规定,该受试物属实际无毒级.三项致突变试验(小鼠骨髓嗜多染红细胞微核试验、小鼠精子畸形试验、Ames试验)结果均为阴性.30d喂养试验结果表明该受试验0.4、1.0、2.0g/kg@bw剂量(分别相当于推荐人群日摄入量0.02g/kg@bw的20、50、100倍)对Wistar大鼠的临床检查、血液学、生化学、脏器重量和系数以及病理组织学等指标无明显影响,未发现该受试物明显的毒性作用.     

Temperature dependence on reaction of CaCO3 and SO2 in O2/CO2 coal combustion

The temperature dependence on the reaction of desulfurization reagent CaCO₃ and SO₂ in O₂/CO₂ coal combustion was investigated by thermogravimetric analysis, X-ray diffraction measurement and pore structure analysis. The results show that the conversion of the reaction of CaCO₃ and SO₂ in air is higher at 500–1 100 °C and lower at 1 200 °C compared with that in O₂/CO₂ atmosphere. The conversion can be increased by increasing the concentration of SO₂, which causes the inhibition of CaSO₄ decomposition and shifting of the reaction equilibrium toward the products. XRD analysis of the product shows that the reaction mechanism of CaCO₃ and SO₂ differs with temperature in O₂/CO₂ atmosphere, i.e. CaCO₃ directly reacts with SO₂ at 500 °C and CaO from CaCO₃ decomposition reacts with SO₂ at 1 000 °C. The pore analysis of the products indicates that the maximum specific surface area of the products accounts for the highest conversion at 1 100 °C in O₂/CO₂ atmosphere. The results reveal that the effect of the atmosphere on the conversion is temperature dependence.     

微量元素硒、锌用于“汉宝”卷烟的研究

1987年7月,我们完成了微量元素硒、锌应用于“汉宝”牌卷烟的研究。结果表明,在卷烟中加入人体必需的微量元素硒、锌,不但能提高吸烟者体内微量元素硒、锌的水平,增强吸烟者的免疫能力,而且对烟气中的有害成份——多环芳烃、焦油自由基有不     

富硒蚕蛹氨基酸水解液的制取及抗肿瘤的初步研究

以陕西紫阳富硒干蛹为原料,经脱脂、提取和酶解得到蚕蛹氨基酸溶液;通过原子荧光分光光度计检测到此溶液含有较高的硒,比非硒地区的蚕蛹硒含量高出几十到几百倍;再以人肝癌细胞株SMMC-7721为模型,用MTT比色法初步研究蚕蛹氨基酸溶液对细胞的作用,结果表明该溶液对细胞有明显的抑制作用,并呈现一定的时效和量效关系.     

载三氧化二砷的PEG—PLGA隐性纳米粒的制备及体外研究

The aim of this study was to prepare arsenic trioxide （ATO）-loaded stealth PEGylated PLGA nanoparticles （PEG-PLGA-NPs） and to assess the merits of PEG-PLGA-NPs as drug carriers for ATO delivery. PEG-PLGA copolymer was synthesized with methoxypolyethyleneglycol （Mw=5000）, D, L-lactide, and glycolide by the ring-opening polymerization method. Amorphous ATO was transformed into cubic crystal form to increase its solu-bility in the organic solvent. ATO-loaded PEG-PLGA-NPs were prepared by the modified spontaneous emulsification solvent diffusion （SESD） method, and the main experimental factors influencing the characteristics of nanopar- ticles were investigated, to optimize the preparation. To confirm the escape of PEG-PLGA-NPs from phagocytosis by phagocytes, PEG-PLGA-NPs labeled rhodamine B uptake by murine peritoneal macrophages （MPM） were analyzed by flow cytometry. The results showed that the physicochemical characteristics of PEG-PLGA-NPs were affected by the type and concentration of the emulsifiers, polymer concentration, and drug concentration. ATO-loaded PEG-PLGA-NPs, with particle size of 120.8nm, zeta potential of-10.73mV, encapsulation efficiency of 73.6%, and drug loading of 1.36%, were prepared under optimal conditions. The images of transmission electron micros-copy （TEM） indicated that the optimized nanoparticles were near spherical and without aggregation or adhesion. The release experiments in vitro showed the ATO release from PEG-PLGA-NPs exhibited consequently sustained release for more than 26d, which was in accordance with Higuchi equation. The uptake of PEG-PLGA-NPs by MPM was found to decrease markedly compared to PLGA-NPs. The experimental results showed that PEG-PLGA-NPs were potential nano drug delivery carriers for ATO.     

泥鳅及其提取物中营养成分的研究

采用国家标准方法测定了泥鳅干粉、活体提取物、胃蛋白酶解提取物中的总蛋白质、总糖、游离氨基酸、水解氨基酸、核黄素（VB2）、烟酸，以及K、Na、Mg、Fe、Zn、Cu、Mn、Se、Pb、Cd、Hg、As等12种无机元素的含量。结果表明：胃蛋白酶解提取物中人体所必需的氨基酸和微量元素含量较高，具有较高的开发价值，为泥鳅的进一步研究和综合利用提供了新的科学依据。