搪瓷元件在脱销改造机组空气预热器的应用

阐述了SCR脱硝机组空预器硫酸氢铵的产生机理,为SCR脱硝机组空预器的改造提供了理论依旧,论述了搪瓷元件的应用原则及应用后的效果。     

二种除草剂对虎纹蛙蝌蚪的毒性研究

研究了二种常用除草剂施田补和百草枯对虎纹蛙Rana rugulosa蝌蚪的毒性。结果表明:随着除草剂浓度的增大,虎纹蛙蝌蚪的死亡率随之提高;百草枯对虎纹蛙蝌蚪的毒性大于施田补,施田补和百草枯对虎纹蛙蝌蚪72 h的半致死浓度(IC50)分别为1.23×10-6L和1.02×10-6L。本研究结果对于合理使用除草剂以有效保护虎纹蛙资源有积极意义。     

“决明山楂燕麦胶囊”的毒理学试验

目的观察决明山楂燕麦胶囊的急性及长期毒性反应,以确保用药安全性。方法急性毒性反应以10 g/kg（小鼠最大耐受量）的决明山楂燕麦给小鼠一次性灌胃,连续观察14 d,逐日记录毒性反应、死亡数,并作病理学检查。长期毒性反应以低剂量组1.6 g/kg、高剂量组2 g/kg给大鼠连续灌服8周,对大鼠进行一般状况、血液学指标、血液生化指标、主要脏器指数和组织病理学观察和检查。结果急性毒性实验未见小鼠出现毒性反应及死亡。长期毒性结果显示,低、高剂量组大鼠的一般状况、体质量、血液学指标、血液生化学指标及主要脏器系数与对照组比较无显著性差异;肉眼观察服药组心、肝、脾、肺、肾外观形态、颜色均无异常改变,光镜检查也未见各脏器组织结构和细胞形态异常。结论决明山楂燕麦对实验动物安全无毒,这可为临床应用提供有用信息。     

蛋白尿的肾毒性与运动性疲劳的伤肾病机及恢复探讨

蛋白尿具有肾毒性，会刺激多种炎症介质、免疫介质及细胞因子的分泌。蛋白尿属中医“尿浊”之范畴，过度运动所致的肾虚、湿热、血瘀是运动性蛋白尿产生的中医病机。蛋白尿与湿、热、瘀是运动性疲劳发生、发展的重要影响因素，是疲劳中导致肾气亏损的发生途径。提示疲劳恢复要补清并重，防治湿、热、瘀等实邪，并注意用微观指标弥补宏观辩证的不足。     

Assessing potential dietary toxicity of heavy metals in selected vegetables and food crops

Heavy metals, such as cadmium, copper, lead, chromium and mercury, are important environmental pollutants, particularly in areas with high anthropogenic pressure. Their presence in the atmosphere, soil and water, even in traces can cause serious problems to all organisms, and heavy metal bioaccumulation in the food chain especially can be highly dangerous to human health. Heavy metals enter the human body mainly through two routes namely： inhalation and ingestion, ingestion being the main route of exposure to these elements in human population. Heavy metals intake by human populations through food chain has been reported in many countries. Soil threshold for heavy metal toxicity is an important factor affecting soil environmental capacity of heavy metal and determines heavy metal cumulative loading limits. For soil-plant system, heavy metal toxicity threshold is the highest permissible content in the soil （total or bioavailable concentration） that does not pose any phytotoxic effects or heavy metals in the edible parts of the crops does not exceed food hygiene standards. Factors affecting the thresholds of dietary toxicity of heavy metal in soil-crop system include： soil type which includes soil pH, organic matter content, clay mineral and other soil chemical and biochemical properties; and crop species or cultivars regulated by genetic basis for heavy metal transport and accumulation in plants. In addition, the interactions of soil-plant root-microbes play important roles in regulating heavy metal movement from soil to the edible parts of crops. Agronomic practices such as fertilizer and water managements as well as crop rotation system can affect bioavailability and crop accumulation of heavy metals, thus influencing the thresholds for assessing dietary toxicity of heavy metals in the food chain. This paper reviews the phytotoxic effects and bioaccumulation of heavy metals in vegetables and food crops and assesses soil heavy metal thresholds for potential dietary toxicity.     

Acute and chronic toxicity studies on partially purified hypoglycemic preparation from water extract of bark ofFicus bengalensis

Acute and chronic toxicity studies were conducted to assess toxicity of a partially purified preparation from the water extract of the bark ofFicus bengalensis, which was demonstrated in our earlier studies to have significant hypoglycemic and hypocholesteroiemic effect on alloxan induced, mild and severe diabetes in rabbits. LD₅₀ of this preparation was found to be ∼1 gm/kg in rats when given orally. For chronic toxicity studies 3 doses of aqueous preparation were given to 3 groups of rats. First group received 5 times ED₅₀ (50 mg/kg), second group 10 times ED₅₀ (100 mg/kg) and the third group 15 times ED₅₀ (150 mg/kg) for 3 months. Fourth group which served as control was given water. After three months, blood was collected for studying biochemical and hematological parameters. Blood glucose, serum cholesterol, liver and kidney function tests, haemoglobin, total and differential leukocyte count were determined. Animals were sacrificed and histopathological examination of liver, heart and kidneys was carried out. Results of the study showed that partially purified preparation fromFicus bengalensis is not toxic by all the above mentioned parameters.     

Ammonium affects cell viability to inhibit root growth in Arabidopsis

Ammonium (NH₄ ⁺) is an important form of nitrogen nutrient for most plants, yet is also a stressor for many of them. However, the primary events of NH₄ ⁺ toxicity at the cellular level are still unclear. Here, we showed that NH₄ ⁺ toxicity can induce the root cell death in a temporal pattern which primarily occurs in the cells of root maturation and elongation zones, and then spreads to the cells in the meristem and root cap. The results from the NH₄ ⁺-hypersensitive mutant hsn1 further confirmed our findings. Taken together, NH₄ ⁺ toxicity inhibits primary root growth by inhibiting cell elongation and division and inducing root cell death.     

草甘膦对3种滩涂动物的急性毒性及安全评价

采用静水法和半静水法检测不同浓度下除草剂草甘膦对缢蛏、可口革囊星虫和大弹涂鱼的急性毒性,并根据·化学农药环境安全评价试验准则·中农药的毒性分级,评价了草甘膦对三种滩涂生物的安全性．结果显示：草甘膦对于缢蛏、可口革囊星虫和大弹涂鱼的96 h LC50分别为233．60,1267．00,1068．00 mg·L－1,均属于低毒;安全浓度分别为23．36,126．70,106．80 mg·L－1,毒性顺序为缢蛏＞大弹涂鱼＞可口革囊星虫．     

广西几种常用中药材药理毒性研究新进展

人们对中药材的毒性及正确的药酒炮制方法不太了解,导致自制药酒毒害性命案件不时发生。因此,必须全面认识中药材的药理毒性作用,高度重视具有一定毒性的中药材,关注其不良反应和毒性反应。文章综述近年来广西几种常用中药材的药理毒性研究新进展,以期进一步掌握广西几种常用中药材的毒性研究新进展,为刑事侦查提供科技支撑。     

Developmental characteristics and response to iron toxicity of root border cells in rice seedlings

To investigate the Fe2 effects on root tips in rice plant, experiments were carded out using border cells in vitro. The border cells were pre-planted in aeroponic culture and detached from root tips. Most border cells have a long elliptical shape. The number and the viability of border cells in situ reached the maxima of 1600 and 97.5%, respectively, at 20～25 mm root length. This mortality was more pronounced at the first 1～12 h exposure to 250 mg/L Fe2 than at the last 12～36 h. After 36 h, the cell viability exposed to 250 mg/L Fe2 decreased to nought, whereas it was 46.5% at 0 mg/L Fe2 . Increased Fe2 dosage stimulated the death of detached border cells from rice cultivars. After 4 h Fe2 treatment, the cell viabilities were≥80% at 0 and 50 mg/L Fe2 treatment and were <62% at 150, 250 and 350 mg/L Fe2 treatment; The viability of border cells decreased by 10% when the Fe2 concentration increased by 100 mg/L. After 24 h Fe2 treatment, the viabilities of border cells at all the Fe2 levels were <65%; The viability of border cells decreased by 20% when the Fe2 concentration increased by 100 mg/L. The decreased viabilities of border cells indicated that Fe2 dosage and treatment time would cause deadly effect on the border cells. The increased cell death could protect the root tips from toxic harm. Therefore, it may protect root from the damage caused by harmful iron toxicity.