Search results for " radical"

Spin trapping as tool for investigating radiation induced free radicals in biologically active molecules

2017

Since from the second half of the last century the spin trapping has found wide applications in chemistry, biology and medicine [1]. Of particular interest are the studied of the free radicals induced in biologically active molecules, such as DNA and proteins, when they are exposed to ionizing radiation. Their characterization allows to investigate the radiation-induced primary processes inside living cells. Indeed, ionizing radiations produce many kinds of free radicals through direct action; radicals can be formed also by indirect actions. However, the direct detection of these radicals is hard to obtain as they have a too short lifetime and this makes difficult to record them by conventi…

ESR spectroscopy for analyzing the spatial distribution of free radicals in ammonium tartrate

2013

Economic conditions and populist radical right voting: The role of issue salience

2021

Contains fulltext : 245174.pdf (Publisher’s version ) (Open Access) In this article, we show with the European Election Study from nine Western European countries that issue salience of the economy and immigration contributes to our understanding of the puzzling relation between economic conditions and populist radical right support. In countries with relatively weak or worsening economic conditions, the economy is considered more salient, whereas immigration loses salience – also compared to other issues. Voters who perceive the economy as most important problem are less likely to opt for the populist radical right than people who perceive immigration or even other issues as most important…

The role of roles in risk management change: the case of an Italian bank

2014

This paper explores the role of roles (i.e. groups of actors characterised by the same functional tasks within an organisation), and of their interactions, within processes of change in risk management (RM). By combining insights from the literature on RM and from institutional studies, this paper suggests that change in RM can be interpreted as a process that involves both enabling and precipitating dynamics [Greenwood, R., & Hinings, C. R. (1996). Understanding radical organizational change: Bringing together the old and the new institutionalism. The Academy of Management Review, 21, 1022–1054. doi:10.5465/AMR.1996.9704071862] between different roles. Aiming to address these dynamic…

ESR Spectra o f Normal Human Serum after Treatment with Complement Activating Agents*

1980

Abstract We describe the appearance of a free-radical signal in the ESR spectrum of normal human serum incubated with several complement activating agents. The intensity of this signal is dependent of dose of activating agents, time and temperature. Signals elicited by different complement activators differ in morphology and kinetics. Inhibition by treatment with EDTA and the presence of the signal in activated C 6-deficient rabbit serum suggest that the con-vertase forming steps of complement activation (C2 to 5) could be the source of free-radical containing molecules.

Computational modeling of isotropic electron paramagnetic resonance spectra of doublet state main group radicals

2007

The combined use of theoretical and mathematical methods in the analysis of electron paramagnetic resonance data has greatly increased the ability to interpret even the most complex spectra reported for doublet state inorganic main group radicals. This personal account summarizes the theoretical basis of such an approach and provides an in-depth discussion of some recent illustrative examples of the utilization of this methodology in practical applications. The emphasis is on displaying the enormous potential embodied within the approach. peerReviewed

Measurement of white wines resistance against oxidation by Electron Paramagnetic Resonance spectroscopy

2018

International audience; Free radical theory of aging hypothesizes that oxygen-derived radicals are responsible for the storage-related flavor instability in wine. In an optimal situation, a balanced-distribution exists between oxidants and antioxidants among wines intrinsic/extrinsic metabolites. Based on the kinetic study of POBN-1-hydroxyethyl spin adduct (POBN-1-HER) formation in wines initiated via the Fenton reaction, a novel tool based on EPR spin trapping methodology was developed to quantify wines resistance against oxidation. Antioxidant capacities of wines were evaluated according to POBN-1-HER maximum signal intensity (Imax POBN-1-HER) and rate formation (r(POBN-1-HER)) kinetic p…

Polynitroxylated hemoglobin-based oxygen carrier: inhibition of free radical-induced microcirculatory dysfunction.

1999

Reactive oxygen species have been identified as key mediators of leukocyte/endothelial cell interaction under various pathological conditions and diseases such as ischemia/reperfusion injury, inflammation, and after exposure to cigarette smoke. Consequently, antioxidants have been shown to successfully prevent the sequelae of these conditions, ranging from tissue infarction to atherogenesis. In this study we investigated whether, via its established superoxide dismutase-like activity, a novel polynitroxyl hemoglobin-based oxygen carrier (PNH), could affect the stimulation of leukocyte rolling and adhesion to endothelial cells in response to cigarette smoke. Using the dorsal skin fold chambe…

Features and application of coupled cold plasma and photocatalysis processes for decontamination of water

2020

Dielectric barrier discharge plasma and photocatalysis have been proposed as tools for decontamination of process water, especially in food industry. The present investigation aims to redefine and identify the features of coupling the two technologies in terms of degradation efficiency of a model compound. Results show that, when the process is carried out in plasma activated water in the presence of irradiated TiO2, the efficiency of the integrated process is lower than the sum of the two processes acting separately. It is proposed that afterglow species, e.g. hydrogen peroxide and/or peroxynitrites could be activated by UVA light irradiation producing hydroxyl radicals in the liquid phase…

Superoxide-driven autocatalytic dark production of hydroxyl radicals in the presence of complexes of natural dissolved organic matter and iron.

2019

Abstract We introduced superoxide as potassium superoxide (KO2) to artificial lake water containing dissolved organic matter (DOM) without or with introduced ferric iron complexes (DOM-Fe(III)), and monitored the production rate of hydroxyl radicals as well as changes in the absorption and fluorescence properties of DOM. The introduction of KO2 decreased the absorption by DOM but increased the spectral slope coefficient of DOM more with complexed ferric Fe than without it. The introduction of KO2 increased the fluorescence of humic-like components in DOM without introduced ferric Fe but resulted in the loss of fluorescence in DOM with introduced ferric Fe. A single introduction of 13 μmol L…