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  1 / 8194 MEDLINE  
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PMID:28278773
Autor:Feng Y; Liao C; Li H; Liu C; Shih K
Endereço:a Department of Civil Engineering , The University of Hong Kong , Hong Kong.
Título:Cu O-promoted degradation of sulfamethoxazole by α-Fe O -catalyzed peroxymonosulfate under circumneutral conditions: synergistic effect, Cu/Fe ratios, and mechanisms.
Fonte:Environ Technol; 39(1):1-11, 2018 Jan.
ISSN:0959-3330
País de publicação:England
Idioma:eng
Resumo:To promote the application of iron oxides in sulfate radical-based advanced oxidation processes, a convenient approach using Cu O as a catalyst additive was proposed. Composite catalysts based on α-Fe O (CTX%Cu O, X = 1, 2.5, 5, and 10) were prepared for peroxymonosulfate (PMS) activation, and sulfamethoxazole was used as a model pollutant to probe the catalytic reactivity. The results show that a synergistic catalytic effect exists between Cu O and α-Fe O , which was explained by the promoted reduction of Fe(III) by Cu(I). Iron K-edge X-ray absorption spectroscopy investigations indicated that the promoted reduction probably occurred with PMS acting as a ligand that bridges the redox centers of Cu(I) and Fe(III). The weight ratio between Cu O and α-Fe O influenced the degradation of sulfamethoxazole, and the optimal ratio depended on the dosage of PMS and catalysts. With 40 mg L PMS and 0.6 g L catalyst, a pseudo-first-order constant of ∼0.019 min was achieved for CT2.5%Cu O, whereas only 0.004 min was realized for α-Fe O . Nearly complete degradation of the sulfamethoxazole was achieved within 180 min under the conditions of 40 mg L PMS, 0.4 g L CT2.5%Cu O, and pH 6.8. In contrast, less than 20% degradation was realized with α-Fe O under similar conditions. The CT2.5%Cu O catalyst had the best stoichiometric efficiency of PMS (0.317), which was 4.5 and 5.8 times higher than those of Cu O (0.070) and α-Fe O (0.054), respectively. On the basis of the products identified, the cleavage of the S-N bond was proposed as a major pathway for the degradation of sulfamethoxazole.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Ferric Compounds); 0 (Peroxides); 0 (Water Pollutants, Chemical); 1K09F3G675 (ferric oxide); 22047-43-4 (peroxymonosulfate); 789U1901C5 (Copper); E1UOL152H7 (Iron); JE42381TNV (Sulfamethoxazole)


  2 / 8194 MEDLINE  
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PMID:28271743
Autor:Wu H; Sun L; Wang H; Wang X
Endereço:a Key Laboratory of Regional Environment and Eco-Remediation , Ministry of Education, Shenyang University , Shenyang , People's Republic of China.
Título:In situ sodium persulfate/calcium peroxide oxidation in remediation of TPH-contaminated soil in 3D-sand box.
Fonte:Environ Technol; 39(1):91-101, 2018 Jan.
ISSN:0959-3330
País de publicação:England
Idioma:eng
Resumo:The aim of this article was to obtain the application parameters and conditions of in situ sodium persulfate/calcium peroxide oxidation. For the purposes of remediation, soil from a total petroleum hydrocarbons (TPH)-contaminated site was collected and prepared to reflect the actual stratum condition in a newly developed soil remediation modeling apparatus. Application methods of soil mixture, natural infiltration, direct injection and groundwater circulation were used to simulate in situ sodium persulfate oxidation in TPH-contaminated soil. Results showed that the transfer capability of Na S O in simulated soil was strong Na S O migrated to the saturated layer after 3 days of in situ injection, which then continued both horizontal and vertical migration. After 7 days the oxidant was widespread in the saturated layer with a radius of influence of 0.4 m. It was found that mixing CaO /Fe /CA with soil and spraying Na S O can effectively repair the surface-contaminated soil, and the longitudinal migration of Na S O in the reaction process can further strengthen the remediation of the upper layer soil. Due to the buffering effect of the soil, the effect of oxidation on the pH and temperature of different soil layers was small, but detectable in comparison to natural environmental factors.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Hydrocarbons); 0 (Peroxides); 0 (Petroleum); 0 (Sodium Compounds); 0 (Soil Pollutants); 0 (Sulfates); 7FRO2ENO91 (calcium peroxide); J49FYF16JE (sodium persulfate)


  3 / 8194 MEDLINE  
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PMID:29478663
Autor:Zhang Q; Liu J; He Y; Yang J; Gao J; Liu H; Tang W; Chen Y; Fan W; Chen X; Chai F; Hatakeyama S
Endereço:College of Environmental & Resource Sciences of Zhejiang University, Hangzhou 310058, China.
Título:Measurement of hydrogen peroxide and organic hydroperoxide concentrations during autumn in Beijing, China.
Fonte:J Environ Sci (China); 64:72-81, 2018 Feb.
ISSN:1001-0742
País de publicação:Netherlands
Idioma:eng
Resumo:Gaseous peroxides play important roles in atmospheric chemistry. To understand the pathways of the formation and removal of peroxides, atmospheric peroxide concentrations and their controlling factors were measured from 7:00 to 20:00 in September, October, and November 2013 at a heavily trafficked residential site in Beijing, China, with average concentrations of hydrogen peroxide (H O ) and methyl hydroperoxide (MHP) at 0.55ppb and 0.063ppb, respectively. H O concentrations were higher in the afternoon and lower in the morning and evening, while MHP concentrations did not exhibit a regular diurnal pattern. Both H O and MHP concentrations increased at dusk in most cases. Both peroxides displayed monthly variations with higher concentrations in September. These results suggested that photochemical activity was the main controlling factor on variations of H O concentrations during the measurement period. Increasing concentrations of volatile organic compounds emitted by motor vehicles were important contributors to H O and MHP enrichment. High levels of H O and MHP concentrations which occurred during the measurement period probably resulted from the transport of a polluted air mass with high water vapor content passing over the Bohai Bay, China.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Air Pollutants); 0 (Peroxides); 0 (Volatile Organic Compounds); BBX060AN9V (Hydrogen Peroxide)


  4 / 8194 MEDLINE  
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PMID:29024887
Autor:Liu Y; Wang Y; Wang Q; Pan J; Zhang J
Endereço:School of Energy and Power Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China. Electronic address: liuyx1984@126.com.
Título:Simultaneous removal of NO and SO using vacuum ultraviolet light (VUV)/heat/peroxymonosulfate (PMS).
Fonte:Chemosphere; 190:431-441, 2018 Jan.
ISSN:1879-1298
País de publicação:England
Idioma:eng
Resumo:Simultaneous removal process of SO and NO from flue gas using vacuum ultraviolet light (VUV)/heat/peroxymonosulfate (PMS) in a VUV spraying reactor was proposed. The key influencing factors, active species, reaction products and mechanism of SO and NO simultaneous removal were investigated. The results show that vacuum ultraviolet light (185 nm) achieves the highest NO removal efficiency and yield of and under the same test conditions. NO removal is enhanced at higher PMS concentration, light intensity and oxygen concentration, and is inhibited at higher NO concentration, SO concentration and solution pH. Solution temperature has a double impact on NO removal. CO concentration has no obvious effect on NO removal. and produced from VUV-activation of PMS play a leading role in NO removal. O and ·O produced from VUV-activation of O also play an important role in NO removal. SO achieves complete removal under all experimental conditions due to its very high solubility in water and good reactivity. The highest simultaneous removal efficiency of SO and NO reaches 100% and 91.3%, respectively.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Air Pollutants); 0 (Gases); 0 (Peroxides); 059QF0KO0R (Water); 0UZA3422Q4 (Sulfur Dioxide); 22047-43-4 (peroxymonosulfate); 31C4KY9ESH (Nitric Oxide); S88TT14065 (Oxygen)


  5 / 8194 MEDLINE  
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PMID:29410988
Autor:Ribar A; Huber SE; Smialek MA; Tanzer K; Neustetter M; Schürmann R; Bald I; Denifl S
Endereço:Institute for Ion Physics and Applied Physics and Center of Molecular Biosciences Innsbruck, Leopold Franzens University of Innsbruck, Technikerstr. 25, 6020 Innsbruck, Austria. stephan.denifl@uibk.ac.at.
Título:Hydroperoxyl radical and formic acid formation from common DNA stabilizers upon low energy electron attachment.
Fonte:Phys Chem Chem Phys; 20(8):5578-5585, 2018 Feb 21.
ISSN:1463-9084
País de publicação:England
Idioma:eng
Resumo:2-Amino-2-(hydroxymethyl)-1,3-propanediol (TRIS) and ethylenediaminetetraacetic acid (EDTA) are key components of biological buffers and are frequently used as DNA stabilizers in irradiation studies. Such surface or liquid phase studies are done with the aim to understand the fundamental mechanisms of DNA radiation damage and to improve cancer radiotherapy. When ionizing radiation is used, abundant secondary electrons are formed during the irradiation process, which are able to attach to the molecular compounds present on the surface. In the present study we experimentally investigate low energy electron attachment to TRIS and methyliminodiacetic acid (MIDA), an analogue of EDTA, supported by quantum chemical calculations. The most prominent dissociation channel for TRIS is through hydroperoxyl radical formation, whereas the dissociation of MIDA results in the formation of formic and acetic acid. These compounds are well-known to cause DNA modifications, like strand breaks. The present results indicate that buffer compounds may not have an exclusive protecting effect on DNA as suggested previously.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Formates); 0 (Free Radicals); 0 (Peroxides); 0YIW783RG1 (formic acid); 9007-49-2 (DNA)


  6 / 8194 MEDLINE  
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PMID:28458145
Autor:Bischin C; Mot A; Stefancu A; Leopold N; Hathazi D; Damian G; Silaghi-Dumitrescu R
Endereço:Department of Chemistry, Babes-Bolyai University, 11 Arany Janos Street, Cluj-Napoca 400028, Romania.
Título:Chlorite reactivity with myoglobin: Analogy with peroxide and nitrite chemistry?
Fonte:J Inorg Biochem; 172:122-128, 2017 Jul.
ISSN:1873-3344
País de publicação:United States
Idioma:eng
Resumo:Stopped-flow UV-vis data allow for the first time direct spectroscopic detection of a ferryl species during the reaction of met myoglobin (Mb) with chlorite, analogous to what is observed in the reaction with peroxides. Ferryl is also observed in the reaction of oxy Mb+chlorite. A pathway involving Fe-O-O-ClO is explored by analogy with the Fe-O-O-NO and Fe-O-O-NO previously proposed as intermediates in the reactions of oxy globins with nitric oxide and nitrite, respectively. However, Fe-O-O-ClO is not detectable in these stopped-flow experiments and is in fact, unlike its nitrogenous congeners, predicted by density functional theory (DFT) to be impossible for a heme complex. Deoxy Mb reacts with chlorite faster than met - suggesting that, unlike with hydrogen peroxide (with which deoxy Mb reacts slower than met), binding of chlorite to the heme is not a rate-determining step (hence, most likely, an outer-sphere electron transfer mechanism); to correlate this, a Fe-O-Cl-O adduct was not observed experimentally for the met or for the deoxy reactions - even though prior DFT calculations suggest it to be feasible and detectable.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Chlorides); 0 (Myoglobin); 0 (Nitrites); 0 (Peroxides); 42VZT0U6YR (Heme); Z63H374SB6 (chlorite)


  7 / 8194 MEDLINE  
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PMID:29121567
Autor:Li Y; Li L; Chen ZX; Zhang J; Gong L; Wang YX; Zhao HQ; Mu Y
Endereço:CAS Key Laboratory of Urban Pollutant Conversion, Collaborative Innovation Centre of Suzhou Nano Science and Technology, Department of Chemistry, University of Science and Technology of China, Hefei, China.
Título:Carbonate-activated hydrogen peroxide oxidation process for azo dye decolorization: Process, kinetics, and mechanisms.
Fonte:Chemosphere; 192:372-378, 2018 Feb.
ISSN:1879-1298
País de publicação:England
Idioma:eng
Resumo:Advanced oxidation processes offer effective solutions in treating wastewater from various industries. This study is the first time to investigate the potential of carbonate-activated hydrogen peroxide (CAP) oxidation process for the removal of organic pollutant from highly alkaline wastewaters. Azo dye acid orange 7 (AO7) was selected as a model pollutant. The influences of various parameters on AO7 decolorization by the CAP oxidation were evaluated. Furthermore, the active species involved in AO7 degradation were explored using scavenger experiments and electron spin resonance analysis. Additionally, AO7 degradation products by the CAP oxidation were identified to elucidate possible transformation pathways. Results showed that the CAP oxidation had better AO7 decolorization performance compared to bicarbonate-activated hydrogen peroxide method. The AO7 decolorization efficiency augmented from 3.70 ± 0.76% to 54.27 ± 2.65% when carbonate concentration was increased from 0 to 50 mM at pH 13.0, and then changed slightly with further increasing carbonate concentration to 70 mM. It increased almost linearly from 5.95 ± 0.32% to 94.03 ± 0.39% as H O concentration was increased from 5 to 50 mM. Moreover, trace amount of Co(II) could facilitate AO7 decolorization by the CAP reaction. Superoxide and carbonate radicals might be the main reactive oxygen species involved in the CAP process. Finally, a possible degradation pathway of AO7 by the CAP oxidation was proposed based on the identified products.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Azo Compounds); 0 (Benzenesulfonates); 0 (Bicarbonates); 0 (Carbonates); 0 (Coloring Agents); 0 (Environmental Pollutants); 0 (Peroxides); BBX060AN9V (Hydrogen Peroxide); Q1LIY3BO0U (2-naphthol orange)


  8 / 8194 MEDLINE  
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PMID:28599858
Autor:Shalan H; Kato M; Cheruzel L
Endereço:San José State University, Department of Chemistry, One Washington Square, San José, CA, United States.
Título:Keeping the spotlight on cytochrome P450.
Fonte:Biochim Biophys Acta; 1866(1):80-87, 2018 01.
ISSN:0006-3002
País de publicação:Netherlands
Idioma:eng
Resumo:This review describes the recent advances utilizing photosensitizers and visible light to harness the synthetic potential of P450 enzymes. The structures of the photosensitizers investigated to date are first presented along with their photophysical and redox properties. Functional photosensitizers range from organic and inorganic complexes to nanomaterials as well as the biological photosystem I complex. The focus is then on the three distinct approaches that have emerged for the activation of P450 enzymes. The first approach utilizes the in situ generation of reactive oxygen species entering the P450 mechanism via the peroxide shunt pathway. The other two approaches are sustained by electron injections into catalytically competent heme domains either facilitated by redox partners or through direct heme domain reduction. Achievements as well as pitfalls of each approach are briefly summarized. This article is part of a Special Issue entitled: Cytochrome P450 biodiversity and biotechnology, edited by Erika Plettner, Gianfranco Gilardi, Luet Wong, Vlada Urlacher, Jared Goldstone.
Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.; REVIEW
Nome de substância:0 (Cadmium Compounds); 0 (Light-Harvesting Protein Complexes); 0 (Peroxides); 0 (Photosensitizing Agents); 0 (Sulfides); 0 (Thioglycolates); 057EZR4Z7Q (cadmium sulfide); 11062-77-4 (Superoxides); 42VZT0U6YR (Heme); 7857H94KHM (2-mercaptoacetate); 9035-51-2 (Cytochrome P-450 Enzyme System); TDQ283MPCW (Eosine Yellowish-(YS))


  9 / 8194 MEDLINE  
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PMID:29176872
Autor:Scrima R; Menga M; Pacelli C; Agriesti F; Cela O; Piccoli C; Cotoia A; De Gregorio A; Gefter JV; Cinnella G; Capitanio N
Endereço:Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy.
Título:Para-hydroxyphenylpyruvate inhibits the pro-inflammatory stimulation of macrophage preventing LPS-mediated nitro-oxidative unbalance and immunometabolic shift.
Fonte:PLoS One; 12(11):e0188683, 2017.
ISSN:1932-6203
País de publicação:United States
Idioma:eng
Resumo:Targeting metabolism is emerging as a promising therapeutic strategy for modulation of the immune response in human diseases. In the presented study we used the lipopolysaccharide (LPS)-mediated activation of RAW 264.7 macrophage-like cell line as a model to investigate changes in the metabolic phenotype and to test the effect of p-hydroxyphenylpyruvate (pHPP) on it. pHPP is an intermediate of the PHE/TYR catabolic pathway, selected as analogue of the ethyl pyruvate (EP), which proved to exhibit antioxidant and anti-inflammatory activities. The results obtained show that LPS-priming of RAW 264.7 cell line to the activated M1 state resulted in up-regulation of the inducible nitric oxide synthase (iNOS) expression and consequently of NO production and in release of the pro-inflammatory cytokine IL-6. All these effects were prevented dose dependently by mM concentrations of pHPP more efficiently than EP. Respirometric and metabolic flux analysis of LPS-treated RAW 264.7 cells unveiled a marked metabolic shift consisting in downregulation of the mitochondrial oxidative phosphorylation and upregulation of aerobic glycolysis respectively. The observed respiratory failure in LPS-treated cells was accompanied with inhibition of the respiratory chain complexes I and IV and enhanced production of reactive oxygen species. Inhibition of the respiratory activity was also observed following incubation of human neonatal fibroblasts (NHDF-neo) with sera from septic patients. pHPP prevented all the observed metabolic alteration caused by LPS on RAW 264.7 or by septic sera on NHDF-neo. Moreover, we provide evidence that pHPP is an efficient reductant of cytochrome c. On the basis of the presented results a working model, linking pathogen-associated molecular patterns (PAMPs)-mediated immune response to mitochondrial oxidative metabolism, is put forward along with suggestions for its therapeutic control.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Anti-Inflammatory Agents); 0 (Hypoxia-Inducible Factor 1, alpha Subunit); 0 (Interleukin-6); 0 (Lipopolysaccharides); 0 (Nitrates); 0 (Nitrites); 0 (Peroxides); 0 (Phenylpyruvic Acids); 0 (Pyruvates); 03O98E01OB (ethyl pyruvate); 156-39-8 (4-hydroxyphenylpyruvic acid); 31C4KY9ESH (Nitric Oxide); EC 1.14.13.39 (Nitric Oxide Synthase Type II)


  10 / 8194 MEDLINE  
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PMID:28939102
Autor:Nauser T; Gebicki JM
Endereço:Laboratorium für Anorganische Chemie, Departement für Chemie und Angewandte Biowissenschaften, Eidgenössische Technische Hochschule (ETH) Zürich, CH - 8093 Zürich, Switzerland. Electronic address: nauser@inorg.chem.ethz.ch.
Título:Reaction rates of glutathione and ascorbate with alkyl radicals are too slow for protection against protein peroxidation in vivo.
Fonte:Arch Biochem Biophys; 633:118-123, 2017 Nov 01.
ISSN:1096-0384
País de publicação:United States
Idioma:eng
Resumo:Reaction kinetics of amino acid and peptide alkyl radicals with GSH and ascorbate, the two most abundant endogenous antioxidants, were investigated by pulse radiolysis. Rate constants in the order of 10 M s were found. Alkyl radicals react at almost diffusion controlled rates and irreversibly with oxygen to form peroxyl radicals, and competition with this reaction is the benchmark for efficient repair in vivo. We consider repair of protein radicals and assume comparable rate constants for the reactions of GSH/ascorbate with peptide alkyl radicals and with alkyl radicals on a protein surface. Given physiological concentrations of oxygen, GSH and ascorbate, protein peroxyl radicals will always be a major product of protein alkyl radicals in vivo. Therefore, if they are formed by oxidative stress, protein alkyl radicals are a probable cause for biological damage.
Tipo de publicação: JOURNAL ARTICLE
Nome de substância:0 (Antioxidants); 0 (Peroxides); 0 (Piperazines); 3170-83-0 (perhydroxyl radical); 47E5O17Y3R (Phenylalanine); GAN16C9B8O (Glutathione); OF5P57N2ZX (Alanine); PQ6CK8PD0R (Ascorbic Acid); S88TT14065 (Oxygen)



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