Publications associées à Superoxyde

Charge-Transfer States in Organic Nanowires

Charge separation processes in organic semiconductors play a pivotal role in diverse applications ranging from photovoltaics to photocatalysis. Understanding these mechanisms, particularly the role of hybrid charge-transfer (CT) states, is essential for ad ...

EPFL2024

Evaluation of the role of superoxide radical as chain carrier for the formation of hydroxyl radical during ozonation

Urs von Gunten, Gang Yu, Yan Wang

Superoxide radicals (O-2(center dot-)) have been suggested as an important chain carrier in the radical chain reaction that promotes ozone (O-3) decomposition to hydroxyl radicals ((OH)-O-center dot) during ozonation. However, due to the difficulty in meas ...

PERGAMON-ELSEVIER SCIENCE LTD2023

Photochemical oxidation of phenols and anilines mediated by phenoxyl radicals in aqueous solution

Urs von Gunten, Silvio Canonica, Stephanie Christa Remke

Reactive intermediates formed upon irradiation of chromophoric dissolved organic matter (CDOM) contribute to the degradation of various organic contaminants in surface waters. Besides well-studied "short-lived" photo oxidants, such as triplet state CDOM (3 ...

PERGAMON-ELSEVIER SCIENCE LTD2022

Mechanistic modelling of solar disinfection (SODIS) kinetics of Escherichia coli, enhanced with H2O2 - Part 2: Shine on you, crazy peroxide

César Pulgarin, Stefanos Giannakis, Ling Feng

In this second part of the development of a mechanistic kinetic model of the solar inactivation of E. coli enhanced with hydrogen peroxide, we evaluate the mechanisms based on photonic inactivation and integrate them into the kinetic model of the dark proc ...

ELSEVIER SCIENCE SA2022

Permanganate Reduction by Hydrogen Peroxide: Formation of Reactive Manganese Species and Superoxide and Enhanced Micropollutant Abatement

Urs von Gunten, Ke Xu

Permanganate (MnO4-, Mn(VII)) is widely applied at the initial stage of water treatment to, e.g., abate taste and odor compounds, Mn(II) and Fe(II). However, its selectivity limits its application for micropollutant abatement. Hydrogen peroxide (H2O2), whi ...

AMER CHEMICAL SOC2021

Generation of hydroxyl radical during chlorination of hydroxyphenols and natural organic matter extracts

Urs von Gunten, Eva Maria Rodriguez Franco

The generation of hydroxyl radicals ((OH)-O-center dot) during the chlorination of air saturated solutions of different hydroxyphenols (hydroquinone, resorcinol, catechol, gallic and tannic acids) at pH 7 has been determined by the formation of phenol (in ...

2020

Mitochondrial Deacetylase Sirt3 Reduces Vascular Dysfunction and Hypertension While Sirt3 Depletion in Essential Hypertension Is Linked to Vascular Inflammation and Oxidative Stress

Johan Auwerx

Rationale: Hypertension represents a major risk factor for stroke, myocardial infarction, and heart failure and affects 30% of the adult population. Mitochondrial dysfunction contributes to hypertension, but specific mechanisms are unclear. The mitochondri ...

2020

Multimodal Response to Copper Binding in Superoxide Dismutase Dynamics

David Lyndon Emsley

Copper/zinc superoxide dismutase (SOD) is a homodimeric metalloenzyme that has been extensively studied as a benchmark for structure-function relationships in proteins, in particular because of its implication in the familial form of the neurodegenerative ...

AMER CHEMICAL SOC2020

Highly stable enzyme-mimicking nanocomposite of antioxidant activity

Bálint Náfrádi, Marko Pavlovic

A highly stable nanocomposite of antioxidant activity was developed by immobilization of a superoxide dismutase-mimicking metal complex on copolymer-functionalized nanoclay. The layered double hydroxide (LDH) nanoclays were synthesized and surface modifica ...

2019

Laser flash photolysis study of the photoinduced oxidation of 4-(dimethylamino)benzonitrile (DMABN)

Urs von Gunten, Frank Jonathan Leresche, Silvio Canonica

Aromatic amines are aquatic contaminants for which phototransformation in surface waters can be induced by excited triplet states of dissolved organic matter ((DOM)-D-3*). The first reaction step is assumed to consist of a one-electron oxidation process of ...

ROYAL SOC CHEMISTRY2019

Pathogenic commonalities between spinal muscular atrophy and amyotrophic lateral sclerosis: Converging roads to therapeutic development

Bernard Schneider

Spinal muscular atrophy (SMA) and amyotrophic lateral sclerosis (ALS) are the two most common motoneuron disorders, which share typical pathological hallmarks while remaining genetically distinct. Indeed, SMA is caused by deletions or mutations in the surv ...

ELSEVIER SCIENCE BV2018

Microbiota-Derived Lactate Activates Production of Reactive Oxygen Species by the Intestinal NADPH Oxidase Nox and Shortens Drosophila Lifespan

Bruno Lemaitre, Jean Philippe Boquete, Igor Iatsenko

Commensal microbes colonize the gut epithelia of virtually all animals and provide several benefits to their hosts. Changes in commensal populations can lead to dysbiosis, which is associated with numerous pathologies and decreased lifespan. Peptidoglycan ...

2018

Oxidative stability and microstructure of 5% fish-oil-enriched granola bars added natural antioxidants derived from brown alga Fucus vesiculosus

Louise Helene Soegaard Jensen

The aims of this study were to (i) investigate the ability of Icelandic brown algae Fucus vesiculosus extracts to inhibit lipid oxidation in granola bars fortified with fish oil-in-water emulsion; (ii) investigate whether addition of the seaweed extracts a ...

Wiley-Blackwell2017

Role of ERK1/2 activation and nNOS uncoupling on endothelial dysfunction induced by lysophosphatidylcholine

Nikolaos Stergiopoulos, Luciano Dos Santos Aggum Capettini

Background and aims: Lysophosphatidylcholine (LPC) - a main component of oxidized LDL -is involved in endothelial dysfunction that precedes atherosclerosis, with an increased superoxide anions and a reduced NO production via endothelial NO synthase (eNOS) ...

Elsevier2017

Mild endothelial dysfunction in Sirt3 knockout mice fed a high-cholesterol diet: protective role of a novel C/EBP-β-dependent feedback regulation of SOD2

Johan Auwerx, Julien Weber

Sirtuin 3 (Sirt3) is an NAD(+)-dependent mitochondrial deacetylase associated with superoxide dismutase 2 (SOD2)-mediated protection from oxidative stress. We have reported accelerated weight gain and impaired metabolic flexibility in atherosclerotic Sirt3 ...

Springer2016

Halide removal from aqueous solution by novel silver-polymeric materials

Urs von Gunten

The objective of this study was to analyze the behavior of a new material, silver-doped polymeric cloth (Ag-cloth), in the removal of bromide and iodide from waters. Silver is immobilized on the cloth, guaranteeing selective adsorption of the halide ions a ...

Elsevier2016

Preparation, kinetics, mechanism and properties of semi-transparent photocatalytic stable films active in dye degradation

César Pulgarin, Juan Kiwi, Laura Victoria Suárez Murillo, Christophe Roussel

The photocatalytic activity, mechanism and characterization of polyethylene-TiO2 films (PE-TiO2) during the discoloration/degradation of methylene blue (MB) are reported in this study. PE-TiO2 films were prepared at moderate temperatures (similar to 90 deg ...

Elsevier2016

SOD1 silencing in motoneurons or glia rescues neuromuscular function in ALS mice

Patrick Aebischer, Bernard Schneider, Christopher Towne, Elisabeth Anne Dirren, Julianne Bobela, Cylia Cloé Rochat

Objective: Amyotrophic lateral sclerosis is an incurable disorder mainly characterized by motoneuron degeneration. Mutations in the superoxide dismutase 1 (SOD1) gene account for 20% of familial forms of the disease. Mutant SOD1 exerts multiple pathogenic ...

Wiley-Blackwell2015

Iron-oxides and iron-citrate as new photocatalysts in solar inactivation of Escherichia coli in water : mechanistic aspects

Cristina del Socorro Lonfat

This study addresses the bacterial inactivation mechanism by photo-Fenton process at near-neutral pH, focusing on iron-oxides and iron-citrate as photocatalysts for solar water disinfection and using E. coli as a bacteria model. Cell envelope damage during ...

EPFL2015

Transcriptomic characterization of the enzymatic antioxidants FeSOD, MnSOD, APX and KatG in the dinoflagellate genus Symbiodinium

Thomas Krüger

Background The diversity of the symbiotic dinoflagellate Symbiodinium sp., as assessed by genetic markers, is well established. To what extent this diversity is reflected on the amino acid level of functional genes such as enzymatic antioxidants that play ...

BioMed Central2015