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排序方式: 共有3733条查询结果,搜索用时 15 毫秒
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Nitro and chlorobenzene compounds, which are widely used in dye industries, have been associated recently with groundwater contamination. Because of their potential toxicity and for taste and odor considerations, three main actions were undertaken to solve the problem. First, to follow the advance of pollution toward the wells, samples were collected automatically and analyzed using GC-MS. Results indicate that o-chloronitrobenzene was the main pollutant in concentrations ranging from 10 to 2000μg/L. Second, to monitor the drinking water quality, an on-line spectrophotometer was used to measure the optical density at 254 nm at the inlet and outlet of the plant. Third, the feasibility of using the O3/H2O9 combination was determined at a 450 L/h pilot plant. Reduction of concentrations of chloronitrobenzenes from 1900 μ/L to less than 20 μg/L could be reached by the application of 8 mg O3/L and 3 mg H2O9/L with a 20-minute contact time. To avoid an eventual bacterial egrowfn in the network due to biodegradability of the oxidation by-products, sand and GAC filtration were tested after oxidation. An evaluation of the costs of these different treatments is also presented. 相似文献
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袁淑云 《柴油机设计与制造》2012,18(2):46-51
燃气计量阀、减压器、低压截止阀是天然气发动机燃气系统中重要的专用件,市场反应D系列天然气发动机专用件报修事故高,为了降低其故障,通过对故障件的外观、基本测试和台架试验分析等,分析出根本原因,提出有效解决措施和管理对策,取得了一定成效. 相似文献
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针对低压计量箱检测信息化、自动化程度较低,存在检测数据孤立、数据记录方式原始、数据难以追溯和数据应用程度较低等问题。文章对现有的低压计量箱检测流程及检测方式进行分析,将现有检测流程与AGV智能调度相融合,将检测流程数字化、信息化,研制了一套低压计量箱智能检测管理系统,实现了低压计量箱检测的信息化。通过实际投运应用和员工调研表明,该系统显著提高了低压计量箱的检测效率,降低了员工的劳动强度,提高检测的公平性、公正性,保障了供货的一致性、可靠性,进一步提升计量箱检测管理水平。 相似文献
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Timo M. Buetler Hélia Latado Estelle Leclerc Bernd Weigle Alexandra Baumeyer Claus W. Heizmann Gabriele Scholz 《Molecular nutrition & food research》2011,55(2):291-299
Scope: Advanced glycation endproducts (AGEs) are suspected to stimulate inflammatory signaling pathways in target tissues via activation of the receptor for AGEs. Endotoxins are generally recognized as potential contamination of AGE preparations and stimulate biological actions that are very similar as or identical to those induced by AGEs. Methods and results: In our study, we used glycolaldehyde‐modified β‐lactoglobulin preparations as model AGEs and employed two methods to remove endotoxin using either affinity columns or extraction with Triton X‐114 (TX‐114). Affinity column‐purified AGEs retained their ability to stimulate inflammatory signaling as measured by mRNA expression of inflammatory cytokines in the human lung epithelial cell line Beas2b. However, glycolaldehyde‐modified AGEs purified by extraction with TX‐114 did not show any stimulation of mRNA expression of inflammatory cytokines. The presence of a cell stimulating endotoxin‐like activity was demonstrated in the detergent phase after extraction with TX‐114, thus indicating that not AGEs but a lipophilic contamination was responsible for the stimulation of inflammatory signaling. Conclusion: Our results demonstrate that glycolaldehyde‐modified AGEs are unable to induce inflammatory signaling in receptor for AGE‐expressing cells. The observed cell‐activating activity can be ascribed to an endotoxin‐like lipophilic contamination present in AGE preparations and affinity column purification was insufficient to remove this contamination. 相似文献
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Formula‐derived advanced glycation end products are involved in the development of long‐term inflammation and oxidative stress in kidney of IUGR piglets 下载免费PDF全文
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The effects of resveratrol on the prevention of apoptosis as well as insulin production are unclear. To examine the effects, we treated insulin-secreting beta cells with methylglyoxal (MG), a metabolite known to induce apoptosis and diabetes in the presence or absence of resveratrol. The MG treatment induced the expression of apoptotic signaling molecules and decreased insulin production. Pretreatment with resveratrol resulted in an increase in insulin synthesis via upregulation of peroxisome proliferator-activated receptor gamma (PPARgamma) and pancreatic-duodenal homeobox-1 (PDX-1). Resveratrol also inhibited MG-mediated expression of CCAAT/enhancer-binding protein beta (C/EBPbeta), a negative regulator of insulin production. Moreover, resveratrol strongly activated the expression of nuclear factor erythroid 2-related factor 2 (Nrf2), which resulted in the attenuation of oxidative stress. These results suggest that resveratrol can attenuate MG-induced oxidative stress in pancreatic cells and increase insulin levels. 相似文献
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George L.J. Hull Jayne V. WoodsideJennifer M. Ames Geraldine J. Cuskelly 《Food chemistry》2012,131(1):170-174
The potential adverse effects on health of diet-derived advanced glycation end-products (AGEs) is of current interest, due to their proposed involvement in the disease progression of diabetic and uraemic conditions. However, accurate information about levels of AGEs in foods is lacking. The objective of this investigation was to determine the level of one particular AGE, Nε-(carboxymethyl)lysine (CML), a marker of AGE formation, in a wide range of foods commonly consumed in a Western style diet. Individual foods (n = 257) were mixed, lyophilised, ground, reduced, fat-extracted, hydrolysed, and underwent solid-phase extraction. Extracts were analysed by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Cereal (2.6 mg/100 g food) and fruit and vegetable (0.13 mg/100 g food) categories had the highest and lowest mean level of CML, respectively, when expressed in mg/100 g food. These data can be used for estimating potential consumer intakes, and provide information that can be used to educated consumers on how to reduce their CML intake. 相似文献