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31.
The oil extracted from Jatropha seeds is an emerging biodiesel feedstock that also contains several pro-inflammatory phorbol esters. These phorbol esters can elicit adverse inflammatory responses through activation of the protein kinase C, as previously described for the prototypical phorbol ester 12-O-tetradecanoylphorbol-13-acetate. We extracted and purified the six phorbol esters identified in Jatropha oil and assessed their pro-inflammatory activities using a recently developed gene expression-based bioassay. Borrowing from an approach used for the assessment of dioxin toxicity, we expressed their pro-inflammatory potencies in relation to the potency of 12-O-tetradecanoylphorbol-13-acetate (in terms of 12-O-tetradecanoylphorbol-13-acetate toxic equivalency factors). The pro-inflammatory potencies of Jatropha phorbol esters were orders of magnitudes below the potency of 12-O-tetradecanoylphorbol-13-acetate. Interestingly, the cytotoxicity of phorbol esters did not appear to be directly related to their pro-inflammatory potencies. Calculations based on phorbol ester potencies and concentrations led to overestimation of the pro-inflammatory activity of Jatropha oil, as measured by the same gene expression-based bioassay. The preliminary results presented here suggest that further work on the described approach may lead to the development of valuable tools and metrics to quantify and predict the pro-inflammatory activities of complex phorbol ester mixtures.  相似文献   
32.
The People's Republic of China (PRC) has the fastest growing economy in the world and is the third largest producer and consumer of energy. At the same time, the PRC's industrial sector contributes heavily to air and water pollution. Because of the linkages between the production and use of energy and environmental degradation, the PRC, with the active support of bilateral and multilateral aid agencies, including the Asian Development Bank (ADB), is adopting measures that link economic growth to improvements in the environment. The PRC is pursuing a two-pronged strategy that involves implementing priority investment programs and promoting economic reforms. The ADB's experience shows that the concept of cleaner production (CP) has been widely accepted, but the widespread adoption of CP requires a new way of thinking and new management capacities. In this regard, the PRC is at an early stage of promoting CP, and inadequacies in coordination among relevant agencies remain a key obstacle. To support CP activities, the ADB is participating in a cluster of activities within China that include policy development, capacity building, and financing environmental investments. This article describes the ADB's current efforts to promote CP in PRC and analyzes the effectiveness of those efforts.  相似文献   
33.
The degradation of some organophosphorus pesticides (OPPs) in the presence of metal ions was studied by 31P-NMR spectroscopy. Both 31P-NMR and gas chromatography/mass spectroscopy results were used in order to determine the nature of metabolites formed after degradation. The degraded organophosphorus pesticide were investigated for chlorpyrifos and phoxim in the presence of several metal ions including Hg2+, Cu2+, Cd2+, Ni2+, Pb2+, and Ag+. 31P-NMR results indicated Ag+ and Hg2+ ion promoted degradation of OPPs and other metal ions formed complex with OPPs and cannot degrade OPPs. We found that the degradation of chlorpyrifos and phoxim with Ag+ or Hg2+ led to the formation of O,O-diethyl-O-methyl phosphorothionate, (C2H5O)2(CH3O)PS, at metal ion/pesticide mole ratios ≤1.0 and completely decomposed at a higher mole ratio of 10. Finally, the method was successfully applied to the degradation study of a number of technical and formulated pesticides in the presence of Ag+ ion at a metal ion/pesticide mole ratio of 10.  相似文献   
34.
Rapid chemical degradation of toxic RDX explosive in soil can be accomplished using zerovalent nanoiron suspension stabilized in dilute carboxymethyl cellulose solution (CMC-ZVINs). The effect of operating conditions (redox-potential, Fe/RDX molar ratio) was studied on batchwise removal of RDX in contaminated soil. While anaerobic conditions resulted in 98% RDX removal in 3 h, only slightly over 60% RDX removal could be attained under aerobic conditions. The molar ratio did not have any influence on the intermediate and final RDX degradation products (methylenedinitramine, nitroso derivative, N2, N2O, NO2?), however, their distribution changed. Dynamic studies were conducted using a flow-through short column packed with RDX-contaminated soil and fed with CMC-ZVINs. The column was operated at two interstitial velocities (2.2 and 1.6 cm min?1), resulting in the 76.6% and 95% removal of the initial RDX soil contamination load (60 mg kg?1), respectively. While the column operating conditions could be further optimized, 95% of the RDX initially present in the contaminated soil packed in the column was degraded when flushed with a CMC-ZVINs suspension in this work.  相似文献   
35.
The concentrations of polychlorinated biphenyls (PCBs) were assessed at four sites in Khour-e-Mousa (Mah-Shahr), Iran. Sea water, sediment and fish (cynoglossus bilineatus) samples were taken at each site and were analysed for PCB levels. To investigate the possible source of PCBs found in fish samples, sediments and waters were collected from four sites (D1, D2, D3, and D4) and studied. The relationship between PCB concentrations in sediment, water and fish is discussed. The results indicate that PCBs are detected in all fish samples and its concentration range from 3.2 to 102.7 μg kg?1 dry weight and 5.4–149.7 μg kg?1 dry weight in cold and warm seasons, respectively. The D2 and D4 sites were found to have the highest and lowest levels of PCB concentrations, respectively. Total congener PCB (CB, 28, 52, 44, 101, 149, 118, 153, 138, and 180) concentrations at the sediment samples for D1, D2, D3, and D4 sites ranged from 1.6 to 30.9 μg kg?1 dry weight and 2.3–47.1 μg kg?1 dry weight in cold and warm seasons, respectively. The total PCB concentrations for D2 site were found to be significantly higher than other three sites. Total water congener PCB (CB, 28, 52, 44, 101, 149, 118, 153, 138, and 180) concentrations ranged from 0.01 to 0.25 μg L?1 and 0.02–0.39 μg L?1 in cold and warm seasons, respectively.  相似文献   
36.
Ahammed GJ  Yuan HL  Ogweno JO  Zhou YH  Xia XJ  Mao WH  Shi K  Yu JQ 《Chemosphere》2012,86(5):546-555
The present study was carried out to investigate the effects of exogenously applied 24-epibrassinolide (BR) on growth, gas exchange, chlorophyll fluorescence characteristics, lipid peroxidation and antioxidant systems of tomato seedlings grown under different levels (0, 10, 30, 100 and 300 μM) of phenanthrene (PHE) and pyrene (PYR) in hydroponics. A concentration-dependent decrease in growth, photosynthetic pigment contents, net photosynthetic rate (Pn), stomatal conductance (Gs), maximal quantum yield of PSII (Fv/Fm), effective quantum yield of PSII (ΦPSII), photochemical quenching coefficient (qP) has been observed following PHE and PYR exposure. By contrast, non-photochemical quenching coefficient (NPQ) was increased. PHE was found to induce higher stress than PYR. However, foliar or root application of BR (50 nM and 5 nM, respectively) alleviated all those depressions with a sharp improvement in the activity of photosynthetic machinery. The activities of guaicol peroxidase (GPOD), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR) as well as content of malondialdehyde (MDA) were increased in a dose-dependent manner under PHE or PYR treatments. Compared with control the highest increments of GPOD, CAT, APX, GR and MDA by PHE/PYR alone treatments were observed following 300 μM concentration, which were 67%, 87%, 53%, 95% and 74% by PHE and 42%, 53%, 30%, 86% and 62% by PYR, respectively. In addition, both reduced glutathione (GSH) and oxidized glutathione (GSSG) were induced by PHE or PYR. Interestingly, BR application in either form further increased enzymatic and non enzymatic antioxidants in tomato roots treated with PHE or PYR. Our results suggest that BR has an anti-stress effect on tomato seedlings contaminated with PHE or PYR and this effect is mainly attributed by increased detoxification activity.  相似文献   
37.
Aroclor 1254 (1860 mg/l) in alkaline 2-propanol and in the presence of acetone (4% v/v) was photodechlorinated to biphenyl at λ >300 nm with exceptionally high quantum yield (Φ= 18). Under similar conditions photodechlorination of extracts of Aroclor 1254 contaminated soil (730 mg/kg) proceeded with lower quantum yield Φ= 0.4. While oxygen severely quenched photolysis, dechlorination was accomplished under thermal conditions using di-t-butyl peroxide, t-BuOOBu-t, as free radical initiator. A free radical chain reaction is suggested in which acetone triplet, T1(n,π*), or t-BuO· radical abstracts H-atom from 2-propanol to give the ketyl radical, (CH3)2 OH, which after losing a proton to the alkaline medium gives the ketyl radical anion, (CH3)2CHO·−. The Aroclor in turn reacts with the latter species through an electron-transfer process giving unstable aryl radical anion, , which cleaves releasing the chloride anion, Cl and the aryl radical, A·  相似文献   
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