Artykuły w czasopismach: „Hydrogen peroxide production”

1

Kusakabe, Ryo. "Hydrogen Peroxide Bleaching. Production, Properties and Handling of Hydrogen Peroxide." JAPAN TAPPI JOURNAL 52, nr 5 (1998): 608–15. http://dx.doi.org/10.2524/jtappij.52.608.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

2

Moy, Terence I., Eleftherios Mylonakis, Stephen B. Calderwood i Frederick M. Ausubel. "Cytotoxicity of Hydrogen Peroxide Produced by Enterococcus faecium". Infection and Immunity 72, nr 8 (sierpień 2004): 4512–20. http://dx.doi.org/10.1128/iai.72.8.4512-4520.2004.

Pełny tekst źródła

Streszczenie:

ABSTRACT Although the opportunistic bacterial pathogen Enterococcus faecium is a leading source of nosocomial infections, it appears to lack many of the overt virulence factors produced by other bacterial pathogens, and the underlying mechanism of pathogenesis is not clear. Using E. faecium-mediated killing of the nematode worm Caenorhabditis elegans as an indicator of toxicity, we determined that E. faecium produces hydrogen peroxide at levels that cause cellular damage. We identified E. faecium transposon insertion mutants with altered C. elegans killing activity, and these mutants were altered in hydrogen peroxide production. Mutation of an NADH oxidase-encoding gene eliminated nearly all NADH oxidase activity and reduced hydrogen peroxide production. Mutation of an NADH peroxidase-encoding gene resulted in the enhanced accumulation of hydrogen peroxide. E. faecium is able to produce hydrogen peroxide by using glycerol-3-phosphate oxidase, and addition of glycerol to the culture medium enhanced the killing of C. elegans. Conversely, addition of glucose, which leads to the down-regulation of glycerol metabolism, prevented both C. elegans killing and hydrogen peroxide production. Lastly, detoxification of hydrogen peroxide either by exogenously added catalase or by a C. elegans transgenic strain overproducing catalase prevented E. faecium-mediated killing. These results suggest that hydrogen peroxide produced by E. faecium has cytotoxic effects and highlight the utility of C. elegans pathogenicity models for identifying bacterial virulence factors.

Style APA, Harvard, Vancouver, ISO itp.

3

Mikashinowich, Z. I., i Ye V. Olempieva. "State of antioxidant blood system at physiological pregnancy and pregnancy complicated with bleeding". Bulletin of Siberian Medicine 7, nr 2 (30.06.2008): 101–5. http://dx.doi.org/10.20538/1682-0363-2008-2-101-105.

Pełny tekst źródła

Streszczenie:

The task of our investigation was the analysis of enzyme activity of antioxidant defense in women blood at physiological pregnancy and pregnancy complicated with hypertension. It was established that hyper production of hydrogen peroxide and glutathione peroxidase activation at physiological pregnancy improved microcirculation due to vasodilatation effect of hydrogen peroxide. It was established that activation of superoxiddysmutase and myeloperoxidase at pregnancy complicated with hypertension developed endothelial dysfunction owing to citotoxic effects of hydrogen peroxide.

Style APA, Harvard, Vancouver, ISO itp.

4

Meizler, A., F. A. Roddick i N. A. Porter. "Continuous enzymatic treatment of 4-bromophenol initiated by UV irradiation". Water Science and Technology 62, nr 9 (1.11.2010): 2016–20. http://dx.doi.org/10.2166/wst.2010.550.

Pełny tekst źródła

Streszczenie:

Horseradish peroxidase (HRP) can be used for the treatment of halogenated phenolic substances. In the presence of hydrogen peroxide phenols are oxidized to form polymers which undergo partial dehalogenation. However, when immobilized, the peroxidase is subject to inactivation due to blockage of the active sites by the growing polymers and to deactivation by elevated levels of hydrogen peroxide. When HRP immobilized on a novel glass-based support incorporating titanium dioxide is subjected to UV irradiation, hydrogen peroxide is produced and the nascent polymer is removed. In this work a reactor was constructed that utilized HRP immobilized on the novel support and the in situ production of hydrogen peroxide to treat 4-bromophenol as a model substrate. The system was operated for almost 17 hours with no apparent decline in activity.

Style APA, Harvard, Vancouver, ISO itp.

5

Šnyrychová, Iva, Péter B. Kós i Éva Hideg. "Hydroxyl radicals are not the protagonists of UV-B-induced damage in isolated thylakoid membranes". Functional Plant Biology 34, nr 12 (2007): 1112. http://dx.doi.org/10.1071/fp07151.

Pełny tekst źródła

Streszczenie:

The production of reactive oxygen species (ROS) was studied in isolated thylakoid membranes exposed to 312 nm UV-B irradiation. Hydroxyl radicals (•OH) and hydrogen peroxide were measured directly, using a newly developed method based on hydroxylation of terephthalic acid and the homovanillic acid/peroxidase assay, respectively. At the early stage of UV-B stress (doses lower than 2.0 J cm–2), •OH were derived from superoxide radicals via hydrogen peroxide. Production of these ROS was dependent on photosynthetic electron transport and was not exclusive to UV-B. Both ROS were found in samples exposed to the same doses of PAR, suggesting that the observed ROS are by-products of the UV-B-driven electron transport rather than specific initiators of the UV-B-induced damage. After longer exposure of thylakoids to UV-B, leading to the inactivation of PSII centres, a small amount of •OH was still observed in thylakoids, even though no free hydrogen peroxide was detected. At this late stage of UV-B stress, •OH may also be formed by the direct cleavage of organic peroxides by UV-B. Immunodetection showed that the presence of the observed ROS alone was not sufficient to achieve the degradation of the D1 protein of PSII centres.

Style APA, Harvard, Vancouver, ISO itp.

6

Marto, Carlos Miguel, Mafalda Laranjo, Anabela Paula, Ana Sofia Coelho, Ana Margarida Abrantes, João Casalta-Lopes, Ana Cristina Gonçalves i in. "Cytotoxic Effects of Zoom® Whitening Product in Human Fibroblasts". Materials 13, nr 7 (25.03.2020): 1491. http://dx.doi.org/10.3390/ma13071491.

Pełny tekst źródła

Streszczenie:

Tooth whitening procedures are increasing; however, side effects can occur, such as damage to pulp cells, by the whitening products. This study aims to assess the cellular effects promoted by a whitening product, namely, the oxidative stress fostered by the active agent hydrogen peroxide, with and without photoactivation. Additionally, if cellular recovery occurred, we intended to determine the time point where cells recover from the tooth whitening induced damage. Human fibroblasts were exposed to hydrogen peroxide, Zoom®, Zoom® + irradiation, and irradiation alone. The following analysis was performed: metabolic activity evaluation by the MTT assay; cell viability, mitochondrial membrane potential, peroxides production, superoxide radical production, and reduced glutathione expression by flow cytometry. We determined the IC50 value for all groups, and a dose-dependent cytotoxic effect was verified. At the times analyzed, hydrogen peroxide groups showed no metabolic activity recovery while a cell recovery was observed after 24 h (Zoom®) and 48 h (Zoom® + irradiation). Cell death was seen in hydrogen peroxide and Zoom® + irradiation groups, mainly by apoptosis, and the irradiation had a cytotoxic effect per se. This in vitro study supports that whitening products with moderate hydrogen peroxide (HP) concentration have a temporary effect on cells, allowing a cellular recovery.

Style APA, Harvard, Vancouver, ISO itp.

7

Shvinka, Juris E., Lolita M. Pankova, Ineta N. Mežbårde i Leons J. Licis. "Hydrogen peroxide production by Zymomonas mobilis". Applied Microbiology and Biotechnology 31, nr 3 (wrzesień 1989): 240–45. http://dx.doi.org/10.1007/bf00258402.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

8

Hou, Yan, Fan Gong Kong, Shou Juan Wang i Gui Hua Yang. "Novel Gas Diffusion Electrode System for Effective Production of Hydrogen Peroxide". Applied Mechanics and Materials 496-500 (styczeń 2014): 159–62. http://dx.doi.org/10.4028/www.scientific.net/amm.496-500.159.

Pełny tekst źródła

Streszczenie:

Hydrogen peroxide production via cathodic reduction of oxygen on self-made gas diffusion electrode was investigated in an undivided electrochemical system. The effects of mass ratio between graphite and PTFE in cathode, the calcination temperature, current density, pH, and plate distance on hydrogen peroxide generation were discussed. The results showed that the self-made gas diffusion cathode had high catalyze capacity for production of hydrogen peroxide using cathodic oxygen-reducing reaction. The hydrogen peroxide concentration could reach 80.52 mg·L- 1 within 2 h. The optimal conditions for this system are as follows: mass ratio of graphite to PTFE in cathode, 21, calcination temperature, 300 °C, current density,4.69mA/cm2, pH 13.0, and the distance between anode and cathode, 8cm. The high concentration of hydrogen peroxide generated gives a promising application of this novel gas diffusion electrode system in pulp bleaching and waste-water treatment.

Style APA, Harvard, Vancouver, ISO itp.

9

Fukuzumi, Shunichi, i Yusuke Yamada. "Thermal and Photocatalytic Production of Hydrogen Peroxide and its Use in Hydrogen Peroxide Fuel Cells". Australian Journal of Chemistry 67, nr 3 (2014): 354. http://dx.doi.org/10.1071/ch13436.

Pełny tekst źródła

Streszczenie:

This mini review describes our recent developments on the thermal and photocatalytic production of hydrogen peroxide and its use in hydrogen peroxide fuel cells. Selective two-electron reduction of dioxygen to hydrogen peroxide by one-electron reductants has been made possible by using appropriate metal complexes with an acid. Protonation of the ligands of the complexes facilitates the reduction of O2. The photocatalytic two-electron reduction of dioxygen to hydrogen peroxide also occurs using organic photocatalysts and oxalic acid as an electron source in buffer solutions. The control of the water content and pH of a reaction solution is significant for improving the catalytic activity and durability. A hydrogen peroxide fuel cell can be operated with a one-compartment structure without a membrane, which is certainly more promising for the development of low-cost fuel cells as compared with two compartment hydrogen fuel cells that require membranes. Utilisation of iron complexes as cathode materials are reviewed.

Style APA, Harvard, Vancouver, ISO itp.

10

Leont'eva, S. V., M. R. Flid, M. A. Trushechkina, M. V. Babotina, V. R. Flid i A. V. Sulimov. "LOW-WASTE TECHNOLOGY OF GLYCIDOL PRODUCTION BY PEROXIDE METHOD". Fine Chemical Technologies 13, nr 3 (28.06.2018): 49–56. http://dx.doi.org/10.32362/24106593-2018-13-3-49-56.

Pełny tekst źródła

Streszczenie:

A technological process of manufacturing glycidol designed for the production capacity of 10 thousand tons per year and consisting in the direct oxidation of allyl alcohol with an aqueous solution of hydrogen peroxide in the presence of nanostructured titanium silicate in methanol is proposed. Due to the exothermic process, the solvent is not only a homogenizer of the mixture of the initial reagents of the epoxy process - allyl alcohol and hydrogen peroxide ensuring their interaction on the surface of the solid catalyst: it also prevents overheating of the reaction mass. On the basis of the research trial of the process the optimal parameters of the process were determined: temperature 30-40 °C; pressure 0.25 MPa; the initial hydrogen peroxide : allyl alcohol ratio = 1:(3-4) mass., methanol concentration in the reaction mixture 12-13 mol/l. Hydrogen peroxide conversion is 98%, the yield of the glycidol - 94%, the selectivity is no less than 95%. The process includes three main stages: (1) raw materials preparation, (2) liquid-phase epoxidation of allyl alcohol, (3) distillation of the target product. The scheme involves recirculation of unreacted allyl alcohol and the solvent - methanol. The developed technological process provides the following indicators (per 1 t of commercial glycidol): consumption of allyl alcohol no more than 0.843 t; consumption of hydrogen peroxide no more than 0.50 t (calculated for 100% hydrogen peroxide); consumption of methanol is no more than 0.022 tons All the waste products correspond to the 3-rd or 4-th hazard class.

Style APA, Harvard, Vancouver, ISO itp.

11

dos Reis, Valdison Pereira, Sulamita da Silva Setúbal, Alex A. Ferreira e Ferreira, Hallison Mota Santana, Milena Daniela Souza Silva, Ortência De Oliveira Sousa, Charles Nunes Boeno, Andreimar M. Soares, Stella R. Zamuner i Juliana P. Zuliani. "Light Emitting Diode Photobiomodulation Enhances Oxidative Redox Capacity in Murine Macrophages Stimulated with Bothrops jararacussu Venom and Isolated PLA2s". BioMed Research International 2022 (15.07.2022): 1–9. http://dx.doi.org/10.1155/2022/5266211.

Pełny tekst źródła

Streszczenie:

Photobiomodulation therapy associated with conventional antivenom treatment has been shown to be effective in reducing the local effects caused by bothropic venoms in preclinical studies. In this study, we analyzed the influence of photobiomodulation using light emitting diode (LED) on the oxidative stress produced by murine macrophages stimulated with Bothrops jararacussu venom and it isolated toxins BthTX-I and BthTX-II. Under LED treatment, we evaluated the activity of the antioxidant enzymes catalase, superoxide dismutase, and peroxidase as well as the release of hydrogen peroxide and the enzyme lactate dehydrogenase. To investigate whether NADPH oxidase complex activation and mitochondrial pathways could contribute to hydrogen peroxide production by macrophages, we tested the effect of two selective inhibitors, apocynin and CCCP3, respectively. Our results showed that LED therapy was able to decrease the production of hydrogen peroxide and the liberation of lactate dehydrogenase, indicating less cell damage. In addition, the antioxidant enzymes catalase, superoxide dismutase, and peroxidase increased in response to LED treatment. The effect of LED treatment on macrophages was inhibited by CCCP3, but not by apocynin. These findings show that LED photobiomodulation treatment protects macrophages, at least in part, by reducing oxidative stress caused B. jararacussu venom and toxins.

Style APA, Harvard, Vancouver, ISO itp.

12

Palenik, Brian, O. C. Zafiriou i F. M. M. Morel. "Hydrogen peroxide production by a marine phytoplankter1". Limnology and Oceanography 32, nr 6 (listopad 1987): 1365–69. http://dx.doi.org/10.4319/lo.1987.32.6.1365.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

13

Zhu, Chongqin, i Joseph S. Francisco. "Production of hydrogen peroxide enabled by microdroplets". Proceedings of the National Academy of Sciences 116, nr 39 (4.09.2019): 19222–24. http://dx.doi.org/10.1073/pnas.1913311116.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

14

Liu, Jiali, Yousheng Zou, Bingjun Jin, Kan Zhang i Jong Hyeok Park. "Hydrogen Peroxide Production from Solar Water Oxidation". ACS Energy Letters 4, nr 12 (13.11.2019): 3018–27. http://dx.doi.org/10.1021/acsenergylett.9b02199.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

15

Jiang, Zhen-Yue, Alison C. S. Woollard i Simon P. Wolff. "Hydrogen peroxide production during experimental protein glycation". FEBS Letters 268, nr 1 (30.07.1990): 69–71. http://dx.doi.org/10.1016/0014-5793(90)80974-n.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

16

Grivennikova, Vera G., Gary Cecchini i Andrei D. Vinogradov. "Ammonium-dependent hydrogen peroxide production by mitochondria". FEBS Letters 582, nr 18 (11.07.2008): 2719–24. http://dx.doi.org/10.1016/j.febslet.2008.06.054.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

17

Giulivi, Cecilia, Paul Hochstein i Kelvin J. A. Davies. "Hydrogen peroxide production by red blood cells". Free Radical Biology and Medicine 16, nr 1 (styczeń 1994): 123–29. http://dx.doi.org/10.1016/0891-5849(94)90249-6.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

18

Hou, Huilin, Xiangkang Zeng i Xiwang Zhang. "Production of Hydrogen Peroxide by Photocatalytic Processes". Angewandte Chemie International Edition 59, nr 40 (18.05.2020): 17356–76. http://dx.doi.org/10.1002/anie.201911609.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

19

De Baerdemaeker, F., M. Šimek, M. Člupek, P. Lukeš i C. Leys. "Hydrogen peroxide production in capillary underwater discharges". Czechoslovak Journal of Physics 56, S2 (październik 2006): B1132—B1139. http://dx.doi.org/10.1007/s10582-006-0339-4.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

20

Papagiannis, Ioannis, Elias Doukas, Alexandros Kalarakis, George Avgouropoulos i Panagiotis Lianos. "Photoelectrocatalytic H2 and H2O2 Production Using Visible-Light-Absorbing Photoanodes". Catalysts 9, nr 3 (6.03.2019): 243. http://dx.doi.org/10.3390/catal9030243.

Pełny tekst źródła

Streszczenie:

Hydrogen and hydrogen peroxide have been photoelectrocatalytically produced by electrocatalytic reduction using simple carbon electrodes made by depositing a mesoporous carbon film on carbon cloth. Visible-light-absorbing photoanodes have been constructed by depositing mesoporous CdS/TiO2 or WO3 films on transparent fluorine-doped tin oxide (FTO) electrodes. Both produced substantial photocurrents of up to 50 mA in the case of CdS/TiO2 and 25 mA in the case of WO3 photoanodes, and resulting in the production of substantial quantities of H2 gas or aqueous H2O2. Maximum hydrogen production rate was 7.8 µmol/min, and maximum hydrogen peroxide production rate was equivalent, i.e., 7.5 µmol/min. The same reactor was employed for the production of both solar fuels, with the difference being that hydrogen was produced under anaerobic and hydrogen peroxide under aerated conditions. The present data promote the photoelectrochemical production of solar fuels by using simple inexpensive materials for the synthesis of catalysts and the construction of electrodes.

Style APA, Harvard, Vancouver, ISO itp.

21

Kregar, Ambroz, Andraž Kravos i Tomaž Katrašnik. "Mathematical Model of Hydrogen Peroxide Production in Anode, Cathode, and Membrane of LT-PEMFC". ECS Meeting Abstracts MA2022-01, nr 35 (7.07.2022): 1524. http://dx.doi.org/10.1149/ma2022-01351524mtgabs.

Pełny tekst źródła

Streszczenie:

Degradation of proton exchange membrane in low-temperature fuel cells represents one of the main limiting factors for wider adoption of this clean, carbon emission free energy device. In combination with mechanical degradation caused by membrane swelling and shrinkage during water content change, chemical degradation of the membrane is considered to be the main mechanism leading to loss of membrane conductivity, membrane thinning and eventual pinhole formation. Chemical degradation is caused by the attack of reactive radical species on the perfluorinated polymer chains of the membrane, which are formed in Fenton reaction between hydrogen peroxide and ions of transition metals, which are inevitably present in the membrane in small traces. Since the metal ions are recycled in Fenton reactions, the rate of chemical degradation is mainly determined by the production of hydrogen peroxide, formed as a side product to water in reaction between oxygen and protons in the fuel cell. [1] The source of hydrogen peroxide production in low-temperature fuel cells have long been debated in scientific literature. On one hand, the abundance of oxygen in the cathode suggest that the production takes place there, but high local electric potential strongly promotes 4-electron reaction, forming water, over 2-electron reaction required for production of hydrogen peroxide [2]. The conditions in the anode are reversed, low electric potential is well suited for peroxide production, but the concentration of oxygen, present in the anode due to diffusion through the membrane, is in general expected to be quite low, making it a rate limiting factor for the peroxide production in the anode. The last possible source of hydrogen peroxide is closely related to the degradation of platinum (Pt) catalyst in the cathode. When Pt catalyst nanoparticles dissolve due to high local electric potential on the cathode, part of the dissolved ions diffuses into the membrane, where it is reduced by counter-diffusing hydrogen from the anode. These Pt particles in the membrane, the so-called Pt band, serve as a catalyst for the reaction between diffusing oxygen from cathode and hydrogen in anode. Since these particles are not electrically connected to either anode or cathode, their electric potential is determined by the rates of oxygen reduction and hydrogen oxidation on their surface, which result in production of water and potentially also hydrogen peroxide. The complex interplay between the processes determining the peroxide production, explained above, suggest that different sources of peroxide might be relevant in different fuel cell operation conditions and at different states of health of the fuel cell. To explore this question quantitatively, we propose a mathematical model of peroxide production which describes physical and electrochemical processes for hydrogen peroxide production in fuel cell catalysts and the membrane, relevant for hydrogen peroxide production: oxygen and hydrogen diffusion in the membrane, electrochemical oxygen reduction in the cathode, anode and on Pt band inside membrane, hydrogen oxidation on Pt band and electric charging of Pt particles in the band due to electrochemical reactions on their surface. To provide realistic internal states of the fuel cell during operation, the model is coupled with advanced spatially and temporally resolved model of the fuel cell operation. [3] Preliminary results of the model indicate that main source of peroxide production depends on the fuel cell operating conditions. In fresh fuel cell, where Pt band in membrane is not yet formed, low current densities and high fuel cell voltages promote the peroxide formation mainly on the anode from the diffused oxygen, while at high current densities the electric potential on the cathode is low enough to allow for significant peroxide production there, outweighing the production on the anode. The formation of the Pt band shifts the production of peroxide from anode to the Pt particles in the band, since large amount of the oxygen is consumed there and therefore its diffusion to the anode is reduced. The results indicate that the question of where the peroxide is formed cannot be resolved by a single answer and that the use of sufficiently complex models, coupling physical and electrochemical processes in different fuel cell components, are required to properly manage fuel cell operation in order to avoid or at least mitigate its detrimental effects of chemical membrane degradation. [1] Frühwirt, P., Kregar, A., Törring, J. T., Katrašnik, T., Gescheidt, G. (2020). Physical Chemistry Chemical Physics, 22(10), 5647–5666. [2] Sethuraman, V. A., Weidner, J. W., Haug, A. T., Motupally, S., Protsailo, L. V. (2008). Journal of The Electrochemical Society, 155(1), B50. [3] Kregar, A., Tavčar, G., Kravos, A., Katrašnik, T. (2020). Applied Energy, 263(March), 114547.

Style APA, Harvard, Vancouver, ISO itp.

22

Papagiannis, Ioannis, Nikolaos Balis, Vassilios Dracopoulos i Panagiotis Lianos. "Photoelectrocatalytic Hydrogen Peroxide Production Using Nanoparticulate WO3 as Photocatalyst and Glycerol or Ethanol as Sacrificial Agents". Processes 8, nr 1 (30.12.2019): 37. http://dx.doi.org/10.3390/pr8010037.

Pełny tekst źródła

Streszczenie:

Photoelectrochemical production of hydrogen peroxide was studied by using a cell functioning with a WO3 photoanode and an air breathing cathode made of carbon cloth with a hydrophobic layer of carbon black. The photoanode functioned in the absence of any sacrificial agent by water splitting, but the produced photocurrent was doubled in the presence of glycerol or ethanol. Hydrogen peroxide production was monitored in all cases, mainly in the presence of glycerol. The presence or absence of the organic fuel affected only the obtained photocurrent. The Faradaic efficiency for hydrogen peroxide production was the same in all cases, mounting up to 74%. The duplication of the photocurrent in the presence of biomass derivatives such as glycerol or ethanol and the fact that WO3 absorbed light in a substantial range of the visible spectrum promotes the presently studied system as a sustainable source of hydrogen peroxide production.

Style APA, Harvard, Vancouver, ISO itp.

23

Pravda, Jay. "Systemic Lupus Erythematosus: Pathogenesis at the Functional Limit of Redox Homeostasis". Oxidative Medicine and Cellular Longevity 2019 (26.11.2019): 1–11. http://dx.doi.org/10.1155/2019/1651724.

Pełny tekst źródła

Streszczenie:

Systemic lupus erythematosus (SLE) is a disease characterized by the production of autoreactive antibodies and cytokines, which are thought to have a major role in disease activity and progression. Immune system exposure to excessive amounts of autoantigens that are not efficiently removed is reported to play a significant role in the generation of autoantibodies and the pathogenesis of SLE. While several mechanisms of cell death-based autoantigenic exposure and compromised autoantigen removal have been described in relation to disease onset, a significant association with the development of SLE can be attributed to increased apoptosis and impaired phagocytosis of apoptotic cells. Both apoptosis and impaired phagocytosis can be caused by hydrogen peroxide whose cellular production is enhanced by exposure to endogenous hormones or environmental chemicals, which have been implicated in the pathogenesis of SLE. Hydrogen peroxide can cause lymphocyte apoptosis and glutathione depletion, both of which are associated with the severity of SLE. The cellular accumulation of hydrogen peroxide is facilitated by the myriad of stimuli causing increased cellular bioenergetic activity that enhances metabolic production of this toxic oxidizing agent such as emotional stress and infection, which are recognized SLE exacerbating factors. When combined with impaired cellular hydrogen peroxide removal caused by xenobiotics and genetically compromised hydrogen peroxide elimination due to enzymatic polymorphic variation, a mechanism for cellular accumulation of hydrogen peroxide emerges, leading to hydrogen peroxide-induced apoptosis and impaired phagocytosis, enhanced autoantigen exposure, formation of autoantibodies, and development of SLE.

Style APA, Harvard, Vancouver, ISO itp.

24

Wolin, M. S., J. M. Rodenburg, E. J. Messina i G. Kaley. "Oxygen metabolites and vasodilator mechanisms in rat cremasteric arterioles". American Journal of Physiology-Heart and Circulatory Physiology 252, nr 6 (1.06.1987): H1159—H1163. http://dx.doi.org/10.1152/ajpheart.1987.252.6.h1159.

Pełny tekst źródła

Streszczenie:

The effects of oxygen metabolites (superoxide anion and hydrogen peroxide) on male Wistar rat cremasteric arterioles and the involvement of these species in the mechanism of vasodilation to arachidonic acid and bradykinin were examined by in vivo television microscopy. In the present study, xanthine oxidase-derived oxygen metabolites from endogenous substrates elicited vasodilation that was selectively and almost completely inhibited by catalase but not by superoxide dismutase. These findings implicate hydrogen peroxide as the vasoactive metabolite generated. Topical application of hydrogen peroxide itself on cremasteric arterioles caused concentration-dependent dilation over the range of 10(-7) to 10(-4) M. Responses to hydrogen peroxide concentrations of up to 10(-5) M were completely inhibited by indomethacin, suggesting that hydrogen peroxide-induced increases in vessel diameter are primarily mediated through the production of vasodilator prostaglandins. In this study, we have not found any evidence to suggest that dilator responses to arachidonic acid or bradykinin are mediated through the extracellular generation of oxygen metabolites. Hydrogen peroxide-induced vasodilation might be involved in the events linking the sensing of oxygen tension through intracellular peroxide formation to the production of vasoactive mediators in the cremasteric microcirculation.

Style APA, Harvard, Vancouver, ISO itp.

25

Bunik, Victoria I., i Martin D. Brand. "Generation of superoxide and hydrogen peroxide by side reactions of mitochondrial 2-oxoacid dehydrogenase complexes in isolation and in cells". Biological Chemistry 399, nr 5 (25.04.2018): 407–20. http://dx.doi.org/10.1515/hsz-2017-0284.

Pełny tekst źródła

Streszczenie:

Abstract Mitochondrial 2-oxoacid dehydrogenase complexes oxidize 2-oxoglutarate, pyruvate, branched-chain 2-oxoacids and 2-oxoadipate to the corresponding acyl-CoAs and reduce NAD+ to NADH. The isolated enzyme complexes generate superoxide anion radical or hydrogen peroxide in defined reactions by leaking electrons to oxygen. Studies using isolated mitochondria in media mimicking cytosol suggest that the 2-oxoacid dehydrogenase complexes contribute little to the production of superoxide or hydrogen peroxide relative to other mitochondrial sites at physiological steady states. However, the contributions may increase under pathological conditions, in accordance with the high maximum capacities of superoxide or hydrogen peroxide-generating reactions of the complexes, established in isolated mitochondria. We assess available data on the use of modulations of enzyme activity to infer superoxide or hydrogen peroxide production from particular 2-oxoacid dehydrogenase complexes in cells, and limitations of such methods to discriminate specific superoxide or hydrogen peroxide sources in vivo.

Style APA, Harvard, Vancouver, ISO itp.

26

Walker, P. D., i S. V. Shah. "Gentamicin enhanced production of hydrogen peroxide by renal cortical mitochondria". American Journal of Physiology-Cell Physiology 253, nr 4 (1.10.1987): C495—C499. http://dx.doi.org/10.1152/ajpcell.1987.253.4.c495.

Pełny tekst źródła

Streszczenie:

Agents that affect mitochondrial respiration have been shown to enhance the generation of reactive oxygen metabolites. On the basis of the well-demonstrated ability of gentamicin to alter mitochondrial respiration (stimulation of state 4 and inhibition of state 3), it was postulated that gentamicin may enhance the generation of reactive oxygen metabolites by renal cortical mitochondria. The aim of this study was to examine the effect of gentamicin on the production of hydrogen peroxide (measured as the decrease in scopoletin fluorescence) in rat renal cortical mitochondria. The hydrogen peroxide generation by mitochondria was enhanced from 0.17 +/- 0.02 nmol . mg-1 . min-1 (n = 14) in the absence of gentamicin to 6.21 +/- 0.67 nmol . mg-1 . min-1 (n = 14) in the presence of 4 mM gentamicin. This response was dose dependent with a significant increase observed at even the lowest concentration of gentamicin tested, 0.01 mM. Production of hydrogen peroxide was not increased when gentamicin was added to incubation media in which mitochondria or substrate was omitted or heat-inactivated mitochondria were used. The gentamicin-induced change in fluorescence was completely inhibited by catalase (but not by heat-inactivated catalase), indicating that the decrease in fluorescence was due to hydrogen peroxide. Thus this study demonstrates that gentamicin enhances the production of hydrogen peroxide by mitochondria. Because of their well-documented cytotoxicity, reactive oxygen metabolites may play a critical role in gentamicin nephrotoxicity.

Style APA, Harvard, Vancouver, ISO itp.

27

Szymczak, R., i TD Waite. "Generation and decay of hydrogen peroxide in estuarine waters". Marine and Freshwater Research 39, nr 3 (1988): 289. http://dx.doi.org/10.1071/mf9880289.

Pełny tekst źródła

Streszczenie:

Apart from its central role in photosynthesis, one of the most dramatic effects of light in marine and freshwater systems is its ability to generate reactive chemical intermediates. Of these, hydrogen peroxide is one of the more stable and easily detected. Aspects of the generation and decay of hydrogen peroxide in the Port Hacking River estuary, New South Wales, have been investigated in a number of field and laboratory studies. Peroxide concentrations in surface waters in the early morning are relatively uniform over the estuary and typically less than 35 nM, whereas concentrations in mid-afternoon in excess of 100 nM have been observed. Variation of peroxide concentration with depth in the deep basins of Port Hacking is dependent on the extent of structure within the water column, with little mixing of surface- generated peroxide into poorly-illuminated bottom waters under stratified conditions. Laboratory studies confirmed that light induces the production of hydrogen peroxide, the initial rate of production increasing with increasing molar absorptivity of the filtered water sample. Filtration of samples had little effect on the generation of hydrogen peroxide but dramatically reduced the rate of decay of photogenerated hydrogen peroxide.

Style APA, Harvard, Vancouver, ISO itp.

28

Monteiro, Mayra K. S., Ángela Moratalla, Cristina Sáez, Elisama V. Dos Santos i Manuel A. Rodrigo. "Production of Chlorine Dioxide Using Hydrogen Peroxide and Chlorates". Catalysts 11, nr 12 (2.12.2021): 1478. http://dx.doi.org/10.3390/catal11121478.

Pełny tekst źródła

Streszczenie:

Chlorine dioxide was produced by the reduction of chlorate with hydrogen peroxide in strongly acidic media. To avoid reaction interference during measuring procedures, UV spectra were acquired to monitor the chlorate reduction. This reduction led to the formation of chlorine dioxide and notable concentrations of chlorite and hypochlorous acid/chlorine, suggesting that the hydrogen peroxide:chlorate ratio is important. Once chlorates are transformed to chlorine dioxide, the surplus hydrogen peroxide promoted the further reaction of the chlorinated species down to less-important species. Moreover, chlorine dioxide was stripped with the outlet gas flow. A linear relationship was established between the amount of limiting reagent consumed and the maximum height of the absorption peak at 360 nm after testing with different ratios of hydrogen peroxide and chlorate, allowing calculations of the maximum amount of chlorine dioxide formed. To verify the reproducibility of the method, a test with four replicates was conducted in a hydrogen peroxide/chlorate solution where chlorine dioxide reduction was not promoted due to the presence of surplus chlorate in the reaction medium after the test. Results confirmed the efficient formation of this oxidant, with maximum concentrations of 8.0 ± 0.33 mmol L−1 in 400–450 min and a conversion percentage of 97.6%. Standard deviations of 0.14–0.49 mmol L−1 were obtained during oxidation (3.6–6.5% of the average), indicating good reproducibility.

Style APA, Harvard, Vancouver, ISO itp.

29

TOIVONEN, PETER M. A., CHANGWEN LU, SUSAN BACH i PASCAL DELAQUIS. "Modulation of Wound-Induced Hydrogen Peroxide and Its Influence on the Fate of Escherichia coli O157:H7 in Cut Lettuce Tissues". Journal of Food Protection 75, nr 12 (1.12.2012): 2208–12. http://dx.doi.org/10.4315/0362-028x.jfp-12-208.

Pełny tekst źródła

Streszczenie:

Wounding of lettuce tissue has been examined previously by others in regard to browning reactions, and treatments to modulate wounding responses were evaluated for reduction of browning. However, the wounding process also releases oxygen radicals such as hydrogen peroxide. This study focused on the evaluation of two treatments that reduce hydrogen peroxide at cut surfaces (heat treatment and pyruvate addition) and one treatment that enhances its production (infusion with the fungal elicitor harpin). Hydrogen peroxide changes in response to treatment were also associated with resultant survival of Escherichia coli O157:H7, which was inoculated onto the lettuce before cutting. Heat-treated lettuce produced significantly less hydrogen peroxide, and microbial analysis showed that E. coli O157:H7 survival on packaged, heat-treated lettuce was higher than on non–heat-treated controls. Lettuce was also cut under a solution of sodium pyruvate (a well-known hydrogen peroxide quencher), and E. coli O157:H7 survival was found to be enhanced with that treatment. When lettuce was infused with harpin before cutting, hydrogen peroxide production was enhanced, and this was associated with reduced survival of E. coli O157:H7. These results collectively support the hypothesis that modulation of wound-generated hydrogen peroxide can have an influence on E. coli O157:H7 survival on cut and packaged romaine lettuce.

Style APA, Harvard, Vancouver, ISO itp.

30

Elsalamony, Radwa A., Dalia R. Abd El-Hafiz, Mohamed A. Ebiad, Abdo M. Mansour i Lamia S. Mohamed. "Enhancement of hydrogen production via hydrogen peroxide as an oxidant". RSC Advances 3, nr 45 (2013): 23791. http://dx.doi.org/10.1039/c3ra43560a.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

31

Kleinveld, H. A., W. Sluiter, A. M. C. Boonman, A. J. G. Swaak, C. E. Hack i J. F. Koster. "Differential stimulation by oxygen-free-radical-altered immunoglobulin G of the production of superoxide and hydrogen peroxide by human polymorphonuclear leucocytes". Clinical Science 80, nr 4 (1.04.1991): 385–91. http://dx.doi.org/10.1042/cs0800385.

Pełny tekst źródła

Streszczenie:

1. The effect of free-radical-altered IgG (monomer and polymer u.v.-irradiated IgG), compared with that of native and heat-aggregated IgG, on the production rate of superoxide anion and hydrogen peroxide by granulocytes (polymorphonuclear leucocytes) from normal blood and granulocytes obtained from the blood and synovial fluid of patients with rheumatoid arthritis was studied. 2. Similar rates of superoxide production by granulocytes from normal blood at rest and in the presence of any form of IgG were found. In contrast, the rate of hydrogen peroxide production could be stimulated in a dose-dependent fashion by monomer or polymer u.v.-irradiated IgG. 3. The stimulatory effect of free-radical-altered IgG on the rate of hydrogen peroxide production did not occur in the presence of 2-deoxyglucose, which deprives the NADPH:O2 oxidoreductase of its substrate NADPH by inhibition of glycolysis and the pentose phosphate pathway. This points to a stimulatory effect on the direct divalent reduction of oxygen without intermediate superoxide production by this enzyme complex. 4. Granulocytes obtained from the blood and synovial fluid of patients with rheumatoid arthritis reacted differently to polymer u.v.-irradiated IgG. In the presence of this stimulus the rate of release of both superoxide and hydrogen peroxide was increased. Furthermore, these granulocytes synthesized superoxide and hydrogen peroxide at a higher rate than did granulocytes from normal blood in the presence of serum-treated zymosan but not in the presence of phorbol myristate acetate. 5. Taken together, these results indicate that the rate of superoxide and hydrogen peroxide production by the granulocyte NADPH:O2 oxidoreductase depends on the pathological condition of the donor and the type of stimulus used.

Style APA, Harvard, Vancouver, ISO itp.

32

Salahudeen, A., K. Badr, J. Morrow i J. Roberts. "Hydrogen peroxide induces 21-aminosteroid-inhibitable F2-isoprostane production and cytolysis in renal tubular epithelial cells." Journal of the American Society of Nephrology 6, nr 4 (październik 1995): 1300–1303. http://dx.doi.org/10.1681/asn.v641300.

Pełny tekst źródła

Streszczenie:

F2-isoprostanes are the newly identified reactive oxygen species-catalyzed peroxidation products of arachidonate. The infusion of these prostaglandin F2-like prostanaoids into the rat kidney induces profound parallel reductions in RBF and GFR, suggesting that these metabolites may be partly responsible for the hemodynamic alterations seen in free radical-linked acute renal injury models. The present study examined directly in renal proximal tubular (LLC-PK1) cells whether hydrogen peroxide, a reactive oxygen species implicated in many models of acute renal injury, induces F2-isoprostane production and whether its production can be inhibited by the recently synthesized lipid peroxidation inhibitor 21-aminosteroid (lazaroid U-74389G). The incubation of LLC-PK1 cell layers with hydrogen peroxide for 3 h resulted in a dose-related six-fold increase in F2-isoprostane production, measured by the gas chromatographic-mass spectroscopic method. The preincubation of cells with 21-aminosteroid prevented hydrogen peroxide-induced F2-isoprostane production, a finding also demonstrable with other lipid peroxidation inhibitors, e.g., 2-methyl aminochroman (U-83836E) and diphenyl-p-phenylenediamine. Besides inhibiting isoprostane production, 21-aminosteroid reduced hydrogen peroxide-induced lipid degradation and peroxidation, and protected the cells against hydrogen peroxide-induced cytolysis. The novel finding that hydrogen peroxide induces 21-aminosteroid-inhibitable F2-isoprostane production in renal epithelial cells supports the in vivo report that its levels are elevated in reactive oxygen species-linked renal injury models such as ischemia-reperfusion. Besides direct cell injury, lipid peroxidation by generating F2-isoprostanes may further contribute to renal dysfunction through a vasoconstrictive mechanism. Thus, the inhibition of excess F2-isoprostane production may be one of the additional mechanisms, besides cytoprotection, by which antioxidants ameliorate renal dysfunction in experimental models of acute renal injury.

Style APA, Harvard, Vancouver, ISO itp.

33

Li, Tian, Jun Deng, Tang Tang Bao i Zhi Jun Wu. "Numerical Study on Effect of Hydrogen Peroxide Additive on Ethanol HCCI Engine". Advanced Materials Research 433-440 (styczeń 2012): 244–50. http://dx.doi.org/10.4028/www.scientific.net/amr.433-440.244.

Pełny tekst źródła

Streszczenie:

In this article, based on a combined chemical mechanism with detailed ethanol oxidization and NO production mechanisms, a single cylinder ethanol HCCI engine model was established using the software CHEMKIN. Comparing with experimental data, this model can well predict cylinder pressure and NO emission. By changing mole fraction of hydrogen peroxide in initial ethanol mixture at different conditions, the effect of hydrogen peroxide additive on ethanol HCCI engine performance was investigated. The results show that hydrogen peroxide can effectively improve cylinder pressure and advance heat release progress, without notably increasing NO production.

Style APA, Harvard, Vancouver, ISO itp.

34

KETTLE, Anthony J., Craig A. GEDYE i Christine C. WINTERBOURN. "Mechanism of inactivation of myeloperoxidase by 4-aminobenzoic acid hydrazide". Biochemical Journal 321, nr 2 (15.01.1997): 503–8. http://dx.doi.org/10.1042/bj3210503.

Pełny tekst źródła

Streszczenie:

Hypochlorous acid is the most powerful oxidant generated by neutrophils and is likely to contribute to the damage mediated by these inflammatory cells. The haem enzyme myeloperoxidase catalyses its production from hydrogen peroxide and chloride. 4-Aminobenzoic acid hydrazide (ABAH) is a potent inhibitor of hypochlorous acid production. In this investigation we show that, in the presence of hydrogen peroxide, ABAH irreversibly inactivates myeloperoxidase. ABAH was oxidized by myeloperoxidase, and kinetic analysis of the inactivation conformed to that for a mechanism-based inhibitor. Inactivation was exacerbated by concentrations of hydrogen peroxide greater than 50 ƁM and by the absence of oxygen. Hydrogen peroxide alone caused minimal inactivation. Reduced glutathione inhibited the oxidation of ABAH as well as the irreversible inhibition of myeloperoxidase. In the presence of oxygen, ABAH and hydrogen peroxide initially converted myeloperoxidase into compound III, which susequently lost haem absorbance. In the absence of oxygen, the enzyme was converted into ferrous myeloperoxidase and its haem groups were rapidly destroyed. We propose that myeloperoxidase oxidizes ABAH to a radical that reduces the enzyme to its ferrous intermediate. Ferrous myeloperoxidase reacts either with oxygen to allow enzyme turnover, or with hydrogen peroxide to give irreversible inactivation.

Style APA, Harvard, Vancouver, ISO itp.

35

Zheltouhova, E. Y., A. N. Kravchenko i E. D. Kondrashina. "Optimization of the production process of solid household soap". Proceedings of the Voronezh State University of Engineering Technologies 81, nr 3 (20.12.2019): 23–27. http://dx.doi.org/10.20914/2310-1202-2019-3-23-27.

Pełny tekst źródła

Streszczenie:

In the study, the main emphasis is on improving organoleptic characteristics (color, smell, structure), as well as foaming ability and storage duration, the change of which will allow to obtain a better product. An organoleptic and qualitative analysis of solid laundry soap was carried out, due to which the main consumer shortcomings of the products were identified and the line and formulation of the production were optimized to eliminate them. The basis of the optimization is to equip additional containers with a peroxide supply and dosage masking system, the use of which is necessary due to the introduction of new formulation components, an additional pair of screws is also used to prevent the marble-like structure of the product. Hydrogen peroxide was included in the recipe, the use of which allows clarifying the product at the stage of carbonate saponification and obtaining a light beige soap in accordance with the standard, and maskirators to hide the smell of fatty acids characteristic of this type of solid soap. Hydrogen peroxide bleaching is based on the oxidation and color loss of coloring dark substances due to the release of active oxygen by heating the peroxide with soaps. The main parameters of the peroxide supply: pressure 0.6 MPa, concentration in the range from 2 to 5% by weight of the fat mixture. Given the possibility of abrupt foaming and ejection of soap in the process, the introduction of peroxide can stop or reduce the amount of hydrogen peroxide added, and in emergency situations a cold water supply is provided.

Style APA, Harvard, Vancouver, ISO itp.

36

Zhou, Li Na, Han Zhao, Yuan Liu, Jing Li, Hao Fei Shi, Yong Gang Wu i Dong Shan Wei. "Synthesis of Graphene Oxide Frameworks and their Application in Electrocatalytic Preparation of Hydrogen Peroxide". Advanced Materials Research 1090 (luty 2015): 43–49. http://dx.doi.org/10.4028/www.scientific.net/amr.1090.43.

Pełny tekst źródła

Streszczenie:

The electrocatalytic performance of graphene oxide frameworks (GOFs) for producing hydrogen peroxide is reported. Three different GOFs are synthesized by interlinking the graphene oxide sheets with different boronic acid deviates through the hydrothermal method and their electrochemical performance are investigated via cyclic voltammetry (CV) and rotating disk electrode (RDE) experiments. Through these electrochemical experiments, we find GOFs favor a 2e-reduction pathway and perform high activity and selectivity in the hydrogen peroxide production process. Taking advantage of these catalysts for the electrochemical synthesis of hydrogen peroxide has the potential to establish a safe, sustainable, and cheap flow-reactor-based production method.

Style APA, Harvard, Vancouver, ISO itp.

37

Miao, Jie, Yong Mei Chen i Ping Yu Wan. "Electrochemical Pre-Oxidation of Drinking Water by On-Site Electro-Generation of Hydrogen Peroxide". Advanced Materials Research 663 (luty 2013): 413–16. http://dx.doi.org/10.4028/www.scientific.net/amr.663.413.

Pełny tekst źródła

Streszczenie:

Hydrogen peroxide is a green oxidizer. On-site electrochemical production of hydrogen peroxide has potential to become a new way for raw water pre-oxidation. The performance of electro-generation hydrogen peroxide was studied in the electrochemical reactor equipped with graphite felt as cathode and RuO2-IrO2-coated titanium mesh as anode. The effect of water flow rate, air flow rate and current density on concentration of hydrogen peroxide and energy consumption was studied. Results indicate that the optimal condition for the lowest energy consumption is to directly produce 5 mg/L of hydrogen peroxide as compared with producing high concentration followed by dilution. It was found that electrochemical pre-oxidation technology had a good effect on sterilization and removing turbidity and stink for raw water.

Style APA, Harvard, Vancouver, ISO itp.

38

Alen’kina, S. A., K. A. Trutneva, V. А. Velikov i V. E. Nikitina. "Study of the Effect of Azospirillum Lectins on the Formation of Hydrogen Peroxide in Wheat Seedling Roots". Izvestiya of Saratov University. Chemistry. Biology. Ecology 12, nr 4 (2012): 56–63. http://dx.doi.org/10.18500/1816-9775-2012-12-4-56-63.

Pełny tekst źródła

Streszczenie:

We show that the lectins isolated from the surface of the nitrogenfixing soil bacterium Azospirillum brasilense Sp7 and its mutant defective in lectin activity, A. brasilense Sp7.2.3., can regulate the production of hydrogen peroxide in wheat seedling roots, which is associated with the activation of superoxide dismutase, peroxidase and oxalate oxidase, as well as with the inhibition of catalase activity. We show that activation of oxalate oxidase is the most rapidly inducible pathway for the formation of hydrogen peroxide in wheat seedling roots under the effect of lectins. The obtained data indicate that the Azospirillum lectins can act as inducers of adaptation processes in wheat seedling roots.

Style APA, Harvard, Vancouver, ISO itp.

39

RAOUF MAHDI, NITHAL. "PRODUCTION AND CHARACTERIZATION OF THREE BRUCELLA ANTIGENS, LIPOPOL- YSACCHRIDE (LPS), SONICATED CELLS AND WHOLE CELLS ANTIGEN". Iraqi Journal of Veterinary Medicine 20, nr 1 (28.06.1996): 13–23. http://dx.doi.org/10.30539/ijvm.v20i1.1569.

Pełny tekst źródła

Streszczenie:

Three types of Brucella abortus antigens were prepared: Lipopolysaccharide (LPS), sonicated cells and whole cells killed antigens. Enzyme-linked immunosorbent assay (ELSIA) was carried out in polysterene microtiter plates using horse-radish peroxidase conjugated to anti- normal bovine serum globuline with hydrogen peroxide and ortho-phenylenediamine as hydrogen as substrate. The results showed that the whole Brucella cells antigen gave the best distinguish between the positive and negative sera with lowest cross reactive with E. coli antiserum

Style APA, Harvard, Vancouver, ISO itp.

40

Santos Andrade, Tatiana, Ioannis Papagiannis, Vassilios Dracopoulos, Márcio César Pereira i Panagiotis Lianos. "Visible-Light Activated Titania and Its Application to Photoelectrocatalytic Hydrogen Peroxide Production". Materials 12, nr 24 (17.12.2019): 4238. http://dx.doi.org/10.3390/ma12244238.

Pełny tekst źródła

Streszczenie:

Photoelectrochemical cells have been constructed with photoanodes based on mesoporous titania deposited on transparent electrodes and sensitized in the Visible by nanoparticulate CdS or CdS combined with CdSe. The cathode electrode was an air–breathing carbon cloth carrying nanoparticulate carbon. These cells functioned in the Photo Fuel Cell mode, i.e., without bias, simply by shining light on the photoanode. The cathode functionality was governed by a two-electron oxygen reduction, which led to formation of hydrogen peroxide. Thus, these devices were employed for photoelectrocatalytic hydrogen peroxide production. Two-compartment cells have been used, carrying different electrolytes in the photoanode and cathode compartments. Hydrogen peroxide production has been monitored by using various electrolytes in the cathode compartment. In the presence of NaHCO3, the Faradaic efficiency for hydrogen peroxide production exceeded 100% due to a catalytic effect induced by this electrolyte. Photocurrent has been generated by either a CdS/TiO2 or a CdSe/CdS/TiO2 combination, both functioning in the presence of sacrificial agents. Thus, in the first case ethanol was used as fuel, while in the second case a mixture of Na2S with Na2SO3 has been employed.

Style APA, Harvard, Vancouver, ISO itp.

41

Tiku, M. L., J. B. Liesch i F. M. Robertson. "Production of hydrogen peroxide by rabbit articular chondrocytes. Enhancement by cytokines." Journal of Immunology 145, nr 2 (15.07.1990): 690–96. http://dx.doi.org/10.4049/jimmunol.145.2.690.

Pełny tekst źródła

Streszczenie:

Abstract Recent evidence suggests that reactive oxygen intermediates may play a role in the etiology of cartilage matrix degradation in arthritis. We have previously established that normal articular chondrocytes can functionally act as macrophages. These functions include expression of class II MHC Ag, presentation of Ag and induction of mixed and autologous lymphocyte stimulation. Inasmuch as the production of reactive oxygen intermediates is a hallmark of macrophage activity during inflammatory response, we were interested in examining the ability of normal articular chondrocytes to produce reactive oxygen intermediates. Using the trapped indicator 2',7'-dichlorofluorescin diacetate (DCFH-DA), we measured the levels of intracellular hydrogen peroxide within normal rabbit articular chondrocytes. We found that Concanavalin A induces chondrocytes to rapidly oxidize 2',7'-dichlorofluorescin diacetate to a highly fluorescent dichlorofluorescin in a dose- and time-dependent manner. Fluorescent dichlorofluorescin oxidation by chondrocytes was inhibited by the addition of catalase, an enzyme that detoxifies hydrogen peroxide. Exposure of rabbit chondrocytes to either IFN-gamma or TNF primed the chondrocytes to produce significantly greater amounts of hydrogen peroxide with or without further stimulation. Using scopoletin oxidation as a measure of the release of hydrogen peroxide, we confirmed that chondrocytes released this reactive oxygen intermediate after adherence to serum coated culture plates. Rabbit articular chondrocytes produced and released greater amounts of hydrogen peroxide than pulmonary alveolar macrophages, a well characterized macrophage cell type. These observations suggest that chondrocytes are an important source of reactive oxygen intermediates. Furthermore, the production of reactive oxygen intermediates by chondrocytes may be an important mechanism by which chondrocytes induce structural and functional alterations in cartilage matrix observed during arthritis.

Style APA, Harvard, Vancouver, ISO itp.

42

Bhatt, Lavinia, Bryan C. Dickinson, David R. Gough, Donal P. O'Leary i Thomas G. Cotter. "Imaging Localised Hydrogen Peroxide Production in Living Systems". Current Chemical Biology 6, nr 2 (4.05.2012): 113–22. http://dx.doi.org/10.2174/187231312801254750.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

43

Nappi, A. J., i E. Vass. "Hydrogen Peroxide Production in Immune-Reactive Drosophila melanogaster". Journal of Parasitology 84, nr 6 (grudzień 1998): 1150. http://dx.doi.org/10.2307/3284664.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

44

Park, In Heon, Kee Byoung Lee, Kyoung Won Song, Jin Yong Lee i Jin Woo Chun. "Hydrogen Peroxide Production in Neutrophils after Tourniquet Release". Journal of the Korean Orthopaedic Association 31, nr 2 (1996): 388. http://dx.doi.org/10.4055/jkoa.1996.31.2.388.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

45

Yarahmadi, Hadis, i Ali Seifitokaldani. "Photocatalytic production of hydrogen peroxide at high throughput". Chem Catalysis 2, nr 7 (lipiec 2022): 1515–16. http://dx.doi.org/10.1016/j.checat.2022.06.013.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

46

Kim, Young Mi, Seung Joon Lee, Hyun Choi, Ho Yeong Kil, Young Joon Yoon, Jin Woo Chun, Kee Byoung Lee i Chan Jeoung Park. "Hydrogen Peroxide Production in Neutrophil after Tourniquet Release". Korean Journal of Anesthesiology 29, nr 1 (1995): 94. http://dx.doi.org/10.4097/kjae.1995.29.1.94.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

47

Moon, Gun-hee. "Design of Photocatalytic Materials for Hydrogen Peroxide Production". Ceramist 25, nr 2 (30.06.2022): 172–83. http://dx.doi.org/10.31613/ceramist.2022.25.2.05.

Pełny tekst źródła

Streszczenie:

Hydrogen peroxide (H2O2) has been widely utilized as an oxidant in diverse industries such as pulp and paper bleaching, chemical synthesis, wastewater treatment, fuel, etc., which has been supplied by anthraquinone process. However, this method needs explosive hydrogen and oxygen gases, high temperature/pressure, massive organic solvent, and noble metal catalysts. The photocatalytic production of H2O2 is cost-effective and environmentally-benign process since only oxygen, water, and light are required. In this review, titanium dioxide (TiO2) and graphitic carbon nitride (g-C3N4) as a representative UVand visible-light-active photocatalyst, respectively, are discussed with overviewing various structure and surface modification techniques in order to improve the photocatalytic H2O2 production. Furthermore, recent studies based on the photoelectrochemical(PEC) H2O2 production are briefly mentioned to understand how the separation of redox-reaction is important to obtain a high apparent quantum yield. Finally, the review proposes the outlook and perspective on the photocatalytic H2O2 production to build-up decentralized wastewater treatment system.

Style APA, Harvard, Vancouver, ISO itp.

48

Mavrikis, Sotirios, Maximilian Göltz, Samuel C. Perry, Felix Bogdan, Pui Ki Leung, Stefan Rosiwal, Ling Wang i Carlos Ponce de León. "Effective Hydrogen Peroxide Production from Electrochemical Water Oxidation". ACS Energy Letters 6, nr 7 (3.06.2021): 2369–77. http://dx.doi.org/10.1021/acsenergylett.1c00904.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

49

Cameli, Fabio, Panagiotis Dimitrakellis, Tai-Ying Chen i Dionisios G. Vlachos. "Modular Plasma Microreactor for Intensified Hydrogen Peroxide Production". ACS Sustainable Chemistry & Engineering 10, nr 5 (28.01.2022): 1829–38. http://dx.doi.org/10.1021/acssuschemeng.1c06973.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

50

Young, Michelle N., Sudeep C. Popat, Bruce E. Rittmann i Cesar I. Torres. "Continuous hydrogen peroxide production in microbial electrochemical cells". Proceedings of the Water Environment Federation 2015, nr 2 (1.01.2015): 1–5. http://dx.doi.org/10.2175/193864715819558154.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Artykuły w czasopismach na temat „Hydrogen peroxide production”

Utwórz poprawne odniesienie w stylach APA, MLA, Chicago, Harvard i wielu innych