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71.
72.
Thays de Andrade Guedes Cristina Moreira-de-Sousa Hellen Maria Soares Lima Tatiane Caroline Grella Priscila Cintra Socolowski Carmem Silvia Fontanetti 《Journal of environmental science and health. Part. B》2020,55(8):687-693
AbstractThe objective of this research was to investigate the potential damage caused by the residual concentrations of the insecticides Regent® WS 800 and Curbix® SC 200, containing fipronil and ethiprole, respectively as active ingredients, on the liver of Oreochromis niloticus. The analyses of HSP70 shock protein labelling and cell death process by TUNEL method were performed in order to measure the effects of the exposure of cell repair system of fish to both insecticides. Statistical analyses showed no significant molecular damage to the hepatic tissue of animals. Nevertheless, variations in HSP70 and DNA fragmentation levels, endpoint of cell repair system response and cellular death, respectively, were observed in several groups. These results indicate that the cell repair machinery was efficient when in contact with residual concentrations of insecticides. However, the DNA fragmentation detected by the TUNEL method suggests that even in face of the cytoprotective action of the HSP70 protein, there are damages that become irreparable. To finish, it is worth mentioning that given the results obtained from residual concentrations, use in the field should be with caution. 相似文献
73.
Schmid A 《Environmental science and pollution research international》2002,9(4):227-229
Mechanical oscillations as well as electrical oscillations (e.g. in an electrical oscillatory circuit) can lead to resonance conditions by external agitation with the natural frequency of the system. During the microbial protein synthesis, the induction and repression mechanisms also cause oscillations in the form of varying protein concentrations. The aim of this work concentrates on an induced resonance case of the biological system, comparable with physical resonance phenomena, by external periodic stimulations. For this, system theoretical computer simulations with a structured genetic model were carried out, which built the theoretical fundament for describing the effect of 'Biological Resonance'. Based on that, lab-scale experiments using a mixed microbial culture (activated sludge) and skimmed milk as an inducing substrate revealed an enhanced microbial productivity of around 60%-75% compared to values of the productivity under steady-state conditions in a narrow range of process parameters. The optimum (resonance case) was confirmed by a repetition of the variation experiments and is characterised by a substrate supply period of approx. 18 min and a following starvation period of about 9 min. Long-term investigations under optimised process conditions indicate adaptation mechanisms of the microorganisms to evade the imposed stress conditions. The productivity will not remain constant without additional stimulation and declines to its original level. However, temporal modulation of the starvation period permanently increases the productivity (elevated catabolism) to about 60%, which was observed over a period of several weeks. 相似文献
74.
采用呼吸计量法考察蛋白泡沫灭火剂组分对其降解性的影响,明确几种国内典型蛋白泡沫灭火剂的生物降解性能。20 d快速生物降解试验结果表明:水解蛋白浓缩液易于生物降解,防腐剂苯酚的添加不会抑制蛋白泡沫灭火剂的生物降解,泡沫稳定剂硫酸亚铁则会对蛋白泡沫灭火剂的生物降解有所影响;6种市售典型蛋白泡沫灭火剂的20 d生物降解率均超过60%,抗溶型蛋白泡沫灭火剂的生物降解性普遍较高;国内蛋白泡沫灭火剂产品的20 d生物降解率远高于国外同类产品,在生物降解性能方面比国外同类产品更具有优势。 相似文献
75.
针对煤质粉末活性炭最显著的热危险特性——自燃危险性进行试验。采用粉尘层最低着火温度测定系统对煤质粉末活性炭进行自燃试验,测定煤质粉末活性炭的最低着火温度;采用SDT Q600热重分析仪测定煤质粉末活性炭在氮气和空气气氛中以20℃/min的速率升温至700℃时的热解和燃烧特性,通过TG/DTG曲线计算其着火温度,并进行热稳定性评价。粉尘层自燃试验结果表明,煤质粉末活性炭最低着火温度为400℃,具有自燃危险性,易形成阴燃;氮气气氛中热解试验表明,热解过程经历了室温~120.0℃和280.0~700.0℃两次轻缓失重阶段,646.44℃时挥发分热失重速率最大,对应热失重速率峰值为0.082 6%/℃,自燃危险性较低;空气气氛中燃烧试验表明,燃烧过程经历了室温~95.5℃和300.0~600.0℃两次剧烈失重阶段,分别为吸附水分受热蒸发和氧化生成的有机官能团分解脱附导致,565.35℃时挥发分热失重速率最大,对应热失重速率峰值为13.20%/min,粉末较强的氧气吸附效应和较低的导热系数导致其自燃倾向较高,火灾危险性较大。 相似文献
76.
77.
78.
蛋白质模式构建消防战勤保障体系的探讨 总被引:1,自引:0,他引:1
战勤保障是一个系统工程,利用蛋白质模式分层次、分功能组建战勤保障中队,不同层级区域战勤保障中心,形成一个多功能的战勤保障网络,在建设中加强评估监督增强战勤保障体系的保障能力. 相似文献
79.
80.
Degradation and detoxification of microcystin-LR in drinking water by
sequential use of UV and ozone
Microcystins (MCs) produced by cyanobacteria are strong hepatotoxins and classified as possible carcinogens.MCs pose a considerable threat to human health through tainted drinking and surface waters.Herein filtrated water from a waterworks in Harbin,China,was spiked with microcystin-LR (MC-LR) extracted from a toxic scum of microcystis aeruginosa,and the spiked sample waters were treated using UV irradiation with consequent ozonation process (UV/O3),compared with ozonation at a dose range commonly applied in water treatment plants,UV irradiation at 254 nm and UV irradiation combined with ozonation (UV+O3),respectively.The remaining of toxins were analyzed using high-performance liquid chromatography and also determined using a protein phosphatase type 2A inhibition assay,which was utilized to evaluate the reduction in toxicity.Results indicated that in comparison to other three processes (O3,UV,and UV+O3),UV/O 3 process could effectively decrease both the concentration and toxicity of MC-LR at 100 μg/L level after 5 min UV irradiation with consequent 5 min ozonation at 0.2 mg/L (below 1 μg/L),while 0.5 mg/L ozone dose was required for the level below 0.1 μg/L.The addition of an UV treatment step to the existing treatment train may induce significant transformation of micropollutants and breaks down the natural organic matters into moieties unfavorable for ozone decomposition,stabilizing the ozone residual.These findings suggested that sequential use of UV and ozone may be a suitable method for the removal of these potentially hazardous microcystins from drinking water. 相似文献