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Showing 1 to 20 of 21 for “"Fenton chemistry"”.
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Hydroxyl radical production via the photo-Fenton reaction in natural waters
… investigates the importance of photo-Fenton chemistry in natural waters. The Fenton reaction, H202 + Fe(ll) [right arrow] Fe(ll) + OH- + OH', can occur in sunlit waters because both H202 and Fe(ll) are photo-chemically produced. Photo-Fenton chemistry was investigated by irradiating …
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The Mechanism of Oxygen and Nitric Oxide Toxicity in Escherichia Coli
… killed cells by damaging their DNA through the Fenton reaction. NO also blocked respiration, an event which previous studies have shown can stimulate oxidative DNA damage. The resultant accumulation of NADH accelerates the reduction of free flavins by flavin reductase, and these reduced flavins …
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Secondary problems caused by the oxyr response to hydrogen peroxide stress in Escherichia coli
… into cells, where it reacts with iron via Fenton chemistry. Three cellular targets are damaged: DNA, mononuclear iron enzymes, and [4Fe-4S] cluster enzymes. E. coli uses the transcription factor OxyR to sense and respond to H2O2 stress. When the intracellular H2O2 levels rise to 0.2 μM, …
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Characterization of Complex Transcriptional Regulation Within the YQJH-YQJI Intergenic Region
… to the potential toxicity of iron as a result of Fenton chemistry, iron homeostasis in humans and other mammals is tightly controlled; this leaves only minute amounts of free iron available to invading pathogenic bacteria. This tight regulation forces pathogenic bacteria to scavenge for iron and …
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The detection and characterisation of novel alkyl spin-adducts of PBN and its derivatives using capillary gas chromatography coupled to electron-ionisation mass spectrometry
… Hydroxyl free radicals were generated by Fenton-based chemistry and reacted with aliphatic aldehydes to produce secondary radicals in the presence of the spin-trapping agent N-tert-butyl-a-phenylnitrone (PBN). Novel aldehyde related radicals were produced via Fenton chemistry and trapped …
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Enhancement in Degradation of Environmental Pollutants: Fenton Degradation of 2,4,6-Trinitrotoluene and Photodegradation of Deepwater Horizon Crude Oil
… has resulted in an urgent need for remediation. Fenton reagent provides an advanced oxidation process that is capable of remediating recalcitrant explosives, such as TNT. One drawback of Fenton chemistry is that the reaction requires acidic pH to prevent precipitation of iron. Our studies have …
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Complexation of Organic Guests and Coordination of Metal Ions by Cyclodextrins: Role of Cyclodextrins in Metal-Guest Interactions
… manufacture, testing, and disposal facilities. Fenton chemistry (ferrous ion catalyzed generation of hydroxyl radicals) has shown utility in the remediation of TNT in soils but it suffers from non-specificity and the need for acidic conditions to prevent loss of iron as iron hydroxides. …
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Detection and analysis of spin trapped radical adducts using thermal desorption gas chromatography mass spectrometry (TD-GC-MS)
… or Mass Spectrometry (MS). In the current study, Fenton chemistry has been used to generate hydroxyl radicals. Sincethe hydroxyl radical adduct of the spin-trap N-tert-butyl-α-phenylnitrone (PBN) is shortlivedat room temperature a secondary trapping technique is employed. The resultingspin-trapped …
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Probing Iron Accumulation in Sacchromyces cerevisiae Using Integrative Biophysical and Biochemical Techniques
… formation of reactive oxygen species (ROS) via Fenton chemistry. Therefore its uptake, trafficking and utilization must be regulated to avoid its toxicological effect. It has been recently discovered that Fe/S cluster biosynthesis machinery plays a key role in the cellular iron regulation and …
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Preparation of azidobrevianamide A and synthetic and biological studies of tetrazomine
… generate hydroxyl radical by Haber- Weiss/Fenton chemistry. Elucidation of this mechanism provided the first evidence of the relative stereochemical configuration of tetrazomine. It was also shown using a 32P-5'-end labeled synthetic oligionucleotide and high-resolution polyacrylamide gel …
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Interactions of Chitin and Lignin Thin Films with Other Molecules
… alcohol (C-alcohol), and degraded through Fenton chemistry with all processes observed by a QCM-D and AFM. The synthetic rate and yield for C-DHP films was lower than DHP films made from coniferyl alcohol (G-alcohol) and p-coumaryl alcohol (H-alcohol). The C-DHP film underwent complete …
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Preparation, Characterization, And Application of Liposomes in the Study of Lipid Oxidation Targeting Hydroxyl Radicals
… studies which generate hydroxyl radicals with Fenton chemistry through bolus additions of iron and hydrogen peroxide do not mimic conditions found physiologically because there is a steady-state concentration of hydrogen peroxide concentration found in normal cellular systems. Also, former …
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Studies of Sustainable Polymers: Novel Lignins to Reprocessable Polymers
… of monolignols and chelator-mediated Fenton chemistry was used to degrade the lignin. With constant monolignol concentration, we found that as the fraction of H in the polymerization feed increased, the amount of lignin formed increased, and the films became more rigid. For the …
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Hydrogen peroxide in the Halls Brook Holding Area, a small meromictic lake
… were used to characterize the lake structure and chemistry and to calculate groundwater inflow and vertical mixing coefficients. Hydrogen peroxide was measured at HBHA between May 1997 and February 1998. Large seasonal variations in hydrogen peroxide concentration were observed, with low (< 0.5 …
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Mechanisms of cell damage and recovery in cryopreserved freshwater protists
… of the highly cytotoxic hydroxyl radical through Fenton chemistry. Elevated antioxidant activities were also detected for those enzymes which remove H2O2, these changes in antioxidant status, when poorly regulated, may in themselves contribute to oxidative stress and imbalances in their complex …
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Identification and characterization of a novel class of hydrogen peroxide targets in escherichia coli
… to accumulation of damage to DAHP synthase by a Fenton reaction between H2O2 and the active-site Fe atom. This damage results in pathway failure and an inability to synthesize aromatic compounds. The cell attempts to compensate by inducing DAHP synthase transcription, but this is not enough. Mn2+ …
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Mechanisms of Iron Oxidation in the Ferroxidase Centre of Escherichia coli Bacterioferritin: A Comparison to Other Ferritins
… role, which may be to prevent uncontrolled Fenton chemistry occurring elsewhere within the bacterium. The experiments and results described in this thesis should be of broad interest to those who study ferritins and iron biochemistry in general.
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Mechanistic Study of Pollutant Degradation
… mechanism of organic pollutant degradation in Fenton reactions and sonochemical reactions. Fenton degradation uses hydroxyl radical to oxidize organic compounds. The radical is produced by catalytic decomposition of hydrogen peroxide with Fe(II). Further research has found that addition of …
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A Fungal secretome tailored to enable a radical (oxidative) wood decay mechanism in brown rot fungi
… of a two-step mechanism that segregated a Fenton-based oxidative phase from a hydrolytic phase in early and late wood decay, respectively. However, although some main differences between white and brown rot fungi have been identified, several details remain obscure. For example, it is …
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A Study of Anisotropic Molecular Rotations by Differential Polarized Phase Fluorometry
Made available in DSpace on 2014-12-14T04:27:46Z (GMT). No. of bitstreams: 1 7913655.pdf: 3356121 bytes, checksum: 81f1468e0929ce4da88ba9de7ea1c59d (MD5) Previous issue date: 1978
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