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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。 相似文献
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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… 相似文献
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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. 相似文献
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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. 相似文献
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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. 相似文献
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