Comparison of single and joint effects of Zn and Cu in continuous flow and batch reactors

BACKGROUND: Microbial behavior in batch reactors may be different from that in continuous flow reactors, which is expected to affect microbial response to heavy metal exposure. Four parallel continuous flow reactors and batch growth tests were used to investigate the single and joint toxicity of Zn and Cu to Artrobacter sp. JM018. RESULTS: The results indicated that Cu is more toxic than Zn under all conditions. In the batch reactors, all Zn concentrations showed a stimulatory effect on microbial growth. However in the continuous system, 125 µmol L^?1 Zn exposure produced inhibition. In the case of mixed Zn and Cu exposures in the batch system, the presence of Zn reduced the severity of Cu inhibition, with a net impact of reduced growth in all cases, whereas in the continuous system microbial growth and substrate utilization rates sharply decreased and ceased. CONCLUSION: The results clearly showed that growth in batch reactors underestimated significantly the heavy metal inhibition, compared with the continuous system. Therefore, the results of batch reactor tests should not be used directly when heavy metal inhibition is to be interpreted for continuous flow systems. Copyright © 2011 Society of Chemical Industry     

Impact of physicochemical properties of cerium oxide nanoparticles on their toxicity effects

The advancing production and application of cerium oxide nanoparticles (CeO₂-NPs) in recent years have raised scientists concern about their toxicity. Numerous investigations have been performed to study the toxicity of CeO₂-NPs although their results are sometimes contradictory. In this review, we display the most important factors that are effective in CeO₂-NPs toxicity. The studies are classified based on the target that is selected for toxicity assessment (cytotoxicity, respiratory toxicity, hepatotoxicity, neurotoxicity, dermal toxicity, phytotoxicity, and environmental toxicity). Various representative examples are presented in each class. It seems to be difficult to achieve a comprehensive view and a deterministic conclusion since several parameters are involved in interpreting the results. In order to reach repeatable and comparable results, it is necessary to design a standard protocol to study the toxicity of CeO₂-NPs. Physicochemical properties of nanoparticles, experiment set up, and toxicity assessment methods are some parameters that should be considered in this standardization.     

Neuroprotective Effects of Triterpene Glycosides from Glycine max against Glutamate Induced Toxicity in Primary Cultured Rat Cortical Cells

To examine the neuroprotective effects of Glycine max, we tested its protection against the glutamate-induced toxicity in primary cortical cultured neurons. In order to clarify the neuroprotective mechanism(s) of this observed effect, isolation was performed to seek and identify active fractions and components. From such fractionation, two triterpene glycosides, 3-O-[α-l-rhamnopyranosyl(1-2)-β-d-glucopyranosyl(1-2)-β-d-glucuronopyranosyl]olean-12-en-3β,22β,24-triol (1) and 3-O-[β-d-glucopyranosyl(1-2)-β-d-galactopyranosyl(1-2)-β-d-glucuronopyranosyl]olean-12-en-3β,22β,24-triol (2) were isolated with the methanol extracts with of air-dried Glycine max. Among these compounds, compound 2 exhibited significant neuroprotective activities against glutamate-induced toxicity, exhibiting cell viability of about 50% at concentrations ranging from 0.1 μM to 10 μM. Therefore, the neuroprotective effect of Glycine max might be due to the inhibition of glutamate-induced toxicity by triterpene glycosides.     

水质的生物毒性检测方法

水质生物毒性检测是水环境质量评价的重要内容。生物检测技术随着各学科间交叉发展的深入而产生了新的活力。该文综述了当前生物毒性检测技术的主要类型以及应用现状,并对未来的重点研究方向提出了一些建议,以期为水毒理学的持续发展提供科学参考。     

丙烷脒杀菌剂的研究进展

丙烷脒是一种新型杀菌剂。主要阐述了丙烷脒的合成方法、杀菌作用、应用优势、现状和发展前景及研究发展方向。     

低毒性刨花板用脲醛树脂胶的研制

对低毒脲醛树脂制造挤压刨花板 (抽空 )的研究结果表明 :采用低毒脲醛树脂 ,不仅挤压刨花板甲醛释放量可以满足E2 级标准 ,而且甲醛释放量可以满足E1 级标准。     

应用发光细菌检测润滑油急性生物毒性评定方法的研究

利用发光细菌为受试生物建立了一套检测润滑油急性毒性的评定方法，该方法具有快速、简便、灵敏、准确、稳定、经济、测定只需微量样品等特点。参照ASTM标准建立了一套样品液的制备方法，引入水融合组分（WAF）和水溶性组分（WSF）概念，采用半数效应载荷皿。作为润滑油在水中生物毒性的判定指标，使润滑油等难溶物质的生物毒性判定更加科学和准确。建立了难溶物质发光菌法水质急性毒性分级标准，为润滑油等难溶物质的毒性评定提供了依据。本文还对相关润滑油进行了评定试验和分级。     

防治美洲斑潜蝇有效药剂的研究及试验方法评价

测定了６种药剂对美洲斑潜蝇成虫的毒力、５种药剂对卵、幼虫和蛹的毒杀作用,并进行了田间药效试验。结果表明,齐墩螨素和高效氯氰菊酯对美液斑潜蝇成虫最敏感,ＬＣ５０分别为０．３２８３及１．５０８６ｍｇ／Ｌ,其毒力分别是乙酰甲胺磷的５８９．２及１２８．２倍。齐墩螨素的混剂菜蝇净和单剂灭虫灵杀卵及杀幼虫的效果优异。５种药剂对蛹均不敏感。２０％菜蝇净乳油和１％灭虫灵乳油分别加水稀释至１０００及３０００倍喷雾,     

95%氟吗啉原药亚慢性经口毒性研究

９５％氟吗啉原药对Ｗｉｓｔａｒ大鼠１３周经口喂饲毒性研究结果表明：３０００ｍｇ／ｋｇ及５０００ｍｇ／ｋｇ浓度组雄鼠体重增长受以不同程度的抑制,肝脏也出现不同程度的肿大,肝功能异常,全部雄鼠肝小叶中心部的细胞肿大;５０００ｍｇ／ｋｇ浓度组雄鼠还表现为平均摄食量减少,食物利用率下降,肾功能异常,并有１只雄鼠记异常、双后肢及爪部红肿。３０００ｍｇ／ｋｇ及５０００ｍｇ／ｋｇ浓度组雌鼠体重增长受到抑制,摄食