甲醛等挥发性物质对大鼠的亚慢性毒性实验

文章研究了不同剂量甲醛等挥发性物质对发育期大鼠体重、血液常规指标、肝肾功能的影响。研究结果表明：甲醛等挥发性物质的混合物能显著降低大鼠体重,而对肝、肾重量无明显影响;可明显提高大鼠血液中血小板（PLT）和嗜酸性粒细胞（EOS）的含量,但对血液中其它常规指标无明显影响;能明显提高大鼠血清中的谷丙转氨酶（ALT）和天冬氨酸氨基转移酶（AST）的活性．对血清中碱性磷酸酶（ALP）、γ-谷氨酰转肽酶（GGT）、血尿素氮（BUN）和肌酐（Cr）无明显影响。     

农药残留对人体健康的危害效应及毒理机制

有机磷农药和有机氯农药是农药残留的两大类型。探讨这两类农药残留对人体健康的危害效应及其毒理机制,提出一些相关防治农药残留的建议。     

三元体系LiCl-NH4Cl-H2O的相平衡研究（0℃，300℃）

测定了三元体系LiCl-NH4Cl-H2O在0℃、30℃时的溶解度和饱和溶液的折光率,绘制了相应的等温溶度图及折光指数图.结果表明0℃和30℃时体系均为简单共饱型,其溶度曲线和折光率曲线均由两支组成,分别对应于LiCl·H2O和NH4Cl.在0℃和30℃时LiCl和NH4Cl共饱点的组成质量分数分别为28.50%,3.50%;44.80%,3.51%.     

钙减缓植物矿质元素毒害的机理

因土壤酸化、盐碱化、重金属污染等多因素导致的矿质元素毒害严重限制了作物生长．钙作为植物必需的元素，在减缓植物矿质元素毒害中起着十分重要的作用．其减缓矿质元素毒害的主要机理可归纳为：施用某些含钙物质如石灰可提高土壤pH值；钙对有害矿质元素的颉颃作用；维持细胞结构和功能的稳定性；维持较高的保护酶系统活力；改善植物的光合作用和呼吸作用以及发挥钙信使系统的功能．     

两种常见农药对大弹涂鱼幼鱼的急性毒性研究

采用静态换水法检测了不同浓度下杀虫剂敌百虫和除草剂草甘膦对大弹涂鱼幼鱼的急性毒性．结果表明,大弹涂鱼幼鱼的死亡率随着农药浓度的升高而增加,并呈显著的相关关系;在水温24-28℃条件下,敌百虫对大弹涂鱼幼鱼48h和96h的半致死浓度（LC50）分别为1．25me4,和1．17mg/L,革甘膦对大弹涂鱼幼鱼48h和96h—LC50分别为335．47mg／L和308．55mg／L．显示了敌百虫和草甘膦对大弹涂鱼幼鱼具有一定潜在危害性．     

液体硝酸铵灌装装置运行总结

随着科学技术的发展进步,采用液体硝酸铵代替固体硝酸铵制备工业炸药,是行业跨越生产技术重点发展的方向之一。本文分析了液体硝酸铵灌装装置的工艺流程、运行效益、存在的问题,并提出相应的整改措施,使装置的稳定性有了很大提高。     

毒理学研究进展及热点

近年来,毒理学发展迅速,在很多领域的研究中发挥着越来越重要的作用。本文根据研究领域分别介绍了描述毒理学、机制毒理学、管理毒理学和人群研究的最新研究进展,并对主要研究热点进行分析,同时对毒理学发展趋势进行了预测。     

How an Evolution View of Workplace Mentoring Relationships Helps Avoid Negative Experiences: The Developmental Relationship Mentoring Model in Action

In this paper, we explore how the use of a specific mentoring model focusing on the evolution of the relationship between mentor and mentee, may influence the incidence of failure. In our research we employed a case study methodology to examine a regional public service mentoring scheme in the UK where a developmental relationship mentoring model had been developed and used to guide practice. Findings indicated toxicity and negative outcomes may be positively influenced by mentor motivation and emotional intelligence, and can be avoided when there is awareness of how relationships develop and evolve. For example, the use of contracting in the early stages can limit the mismatched expectations that provoke disappointment, but equally mentor actions at other stages play key roles in reducing potential failure. Our study has implications for the enhancement of mentor training and scheme coordination as well as contributing to the understanding of negative mentoring relationships.     

Pleurotus Ostreatus液体发酵生物学特性与产毒条件的探索

本试验着重探讨了粗皮侧耳在液体发酵条件下产生杀线虫毒素的影响因子，试验结果表明：粗皮侧耳液体发酵的最适温度为28℃，最适pH值范围5．0～6．5，群体发酵生长规律符合“S”型增长曲线，营养生长期8～10天，指数增长期从发酵的第2天开始，至第8天结束，对发酵液的活性初步测定结果表明，指数增长期间不产生杀线虫毒素，产生杀线虫毒素的时间在稳定期后期至衰亡期。活线虫及其未灭菌代谢物、酵母膏(1％)、乙醇(3％)能显著提高粗皮侧耳发酵液中的杀线虫毒素浓度。     

Purification and characterization of keratinase from a new Bacillus subtilis strain

The aim of this study was to purify and characterize a keratinase produced by a new isolated Bacillus subtilis KD-N2strain. The keratinase produced by the isolate was purified using ammonium sulphate precipitation, Sephadex G-75 and DEAE (diethylaminoethyl)-Sepharose chromatographic techniques. The purified enzyme was shown to have a molecular mass of 30.5kDa, as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis. The optimum pH at 50℃ was 8.5 and the optimum temperature at pH 8.5 was 55℃. The keratinase was partially inactivated by some metal ions, organic solvents and serine protease inhibitor phenylmethanesulfonyl fluoride (PMSF). Sodium dodecyl sulfate (SDS) and ethylene diamine tetraacetic acid (EDTA) had positive effect on the keratinase activity. Reducing agents including dithiothreitol (DTT),mercaptoethanol, L-cysteine, sodium sulphite, as well as chemicals of SDS, ammonium sulfamate and dimethylsulfoxide (DMSO)stimulated the enzyme activity upon a feather meal substrate. Besides feather keratin, the enzyme is active upon the soluble proteins ovalbumin, bovine serum albumin (BSA), casein and insoluble ones as sheep wool and human hair. Calf hair, silk and collagen could not be hydrolyzed by the keratinase.