Search results for "Oxidation reduction"

Biopolyester-based systems containing naturally occurring compounds with enhanced thermooxidative stability

2016

Background This work presents a sustainable approach for the stabilization of polylactic acid (PLA) against thermo-oxidative aging. Methods Naturally occurring phenolic and polyphenolic compounds, such as ferulic acid (FerAc), vanillic acid (VanAc), quercetin (Querc) and vitamin E (VitE), were introduced into PLA. Results The preliminary characterization of the systems formulated containing different amounts of natural stabilizers showed that all compounds used acted as plasticizers, leading to a decrease in rheological functions with respect to neat PLA, without significantly modifying the crystallinity of the raw material. The study of the thermo-oxidative behavior of neat PLA and PLA/nat…

Correspondence: Strongly-driven Re+CO2 redox reaction at high-pressure and high-temperature.

2016

Correspondence: Strongly-driven Re+CO 2 redox reaction at high-pressure and high-temperature

Monitoring pH and ORP in a SHARON reactor

2011

This paper analyses the valuable information provided by the on-line measurements of pH and oxidation reduction potential (ORP) in a continuous single high ammonia removal over nitrite (SHARON) reactor. A laboratory-scale SHARON reactor equipped with pH, ORP, electric conductivity and dissolved oxygen (DO) probes has been operated for more than one year. Nitrogen removal over nitrite has been achieved by adding methanol at the beginning of anoxic stages. Time evolution of pH and ORP along each cycle allows identifying the decrease in nitritation rate when ammonia is consumed during the aerobic phase and the end of the denitrification process during the anoxic phase. Therefore, monitoring pH…

Synthesis, characterization and a voltammetric study of (Bu4N)2[Mo2Br6]. Oxidation-reduction mechanism of related compounds

1984

The synthesis and characterization of (Bu4N)2[Mo2Br6], obtained from Mo(CO)6, (Bu4N)Br and 1,2-dibromoethane, is described. The electrochemical behaviour of [Mo2Br6]−2 and related species is studied, and an oxidation-reduction mechanism is proposed.

7-Ketocholesterol as marker of cholesterol oxidation in model and food systems: when and how.

2014

Cholesterol can undergo oxidation through enzymatic or chemical mechanisms, generating a wide range of oxidation products (COPs) with adverse biological effects. COPs are characterized by different functional groups and are produced in different ratios or amounts, depending on the treatment and storage conditions. To follow the cholesterol oxidation process, 7-ketocholesterol (7-KC) has been often used as an oxidation marker in both model and food systems, since it is easily formed and is one of the most representative ring COPs. However, 7-KC does not always rise with increasing time/temperature conditions, especially in complex systems and high-protein or extensively processed foods. The …

Screening of lactic acid bacteria for reducing power using a tetrazolium salt reduction method on milk agar.

2013

WOS:000315703100020 ; www.elsevier.com/locate/jbiosc; International audience; Reducing activity is a physiological property of lactic acid bacteria (LAB) of technological importance. We developed a solid medium with tetrazolium dyes enabling weakly and strongly reducing LAB to be discriminated. It was used to quantify populations in a mixed culture (spreading method) and screen strains (spot method).

Expression of NO synthases and redox enzymes in umbilical arteries from newborns born small, appropriate, and large for gestational age.

2012

Modified expression of nitric oxide synthases (NOSs) and an imbalance between the pro-oxidative and the antioxidative system accompany endothelial dysfunction, the first stage of atherosclerosis. Humans born small (SGA) or large (LGA) for gestational age are at higher risk of developing atherosclerosis later in life than humans born appropriate for gestational age (AGA). We hypothesized that indicators of endothelial dysfunction could be detectable at birth. The purpose of this study was to find out whether the expression patterns of NO synthases (endothelial NOS (eNOS), inducible NOS (iNOS), and neuronal NOS (nNOS)), pro-oxidative enzymes (components of nicotinamide adenine dinucleotide ph…

Untersuchungen zur mikrobiellen Benzoloxydation

1958

Dicopper(II) Anthraquinophanes as Multielectron Reservoirs for Oxidation and Reduction: A Joint Experimental and Theoretical Study

2014

Two new dinuclear copper(II) metallacyclophanes with 1,4-disubstituted 9,10-anthraquinonebis(oxamate) bridging ligands are reported that can reversibly take and release electrons at the redox-active ligand and metal sites, respectively, to give the corresponding mono- and bis(semiquinonate and/or catecholate) Cu(II)2 species and mixed-valent Cu(II)/Cu(III) and high-valent Cu(III)2 ones. Density functional calculations allow us to give further insights on the dual ligand- and metal-based character of the redox processes in this novel family of antiferromagnetically coupled di- copper(II) anthraquinophanes. This unique ability for charge storage could be the basis for the development of new k…

Electroorganic synthesis of nitriles via a halogen-free domino oxidation–reduction sequence

2015

A direct electroorganic sequence yielding nitriles from oximes in undivided cells is reported. Despite the fact that intermediate nitrile oxides might be formed, the method is viable to prepare benzonitriles without substituents ortho to the aldoxime moiety. This constant current method is easy to perform for a broad scope of substrates and employs common electrodes, such as graphite and lead.