Effects of radio-frequency fields on bacterial cell membranes and nematode temperature-sensitive mutants

Membrane-related bioeffects have been reported in response to both radio-frequency (RF) and extremely low-frequency (ELF) electromagnetic fields (EMFs), particularly in neural cells. We have tested whether RF fields might cause inner membrane leakage in ML35 E. coli cells, which express β-galactosidase (lacZ) constitutively, but lack the lacY permease required for substrate entry. The activity of lacZ (indicating substrate leakage through the inner cell membrane) was increased only slightly by RF exposure (1 GHz, 0.5 W) over 45 min. Since lacZ activity showed no further increase with a longer exposure time of 90 min, this suggests that membrane permeability per se is not significantly affected by RF fields, and that slight heating (≤ 0.1°C) could account for this small difference. Temperature-sensitive (ts) mutants of the nematode, Caenorhabditis elegans, are wild-type at 15°C but develop the mutant phenotype at 25°C; an intermediate temperature of 21°C results in a reproducible mixture of both phenotypes. For two ts mutants affecting transmembrane receptors (TRA-2 and GLP-1), RF exposure for 24 h during the thermocritical phase strongly shifts the phenotype mix at 21°C towards the mutant end of the spectrum. For ts mutants affecting nuclear proteins, such phenotype shifts appear smaller (PHA-1) or non-significant (LIN-39), apparently confirming suggestions that RF power is dissipated mainly in the plasma membrane of cells. However, these phenotype shifts are no longer seen when microwave treatment is applied at 21°C in a modified exposure apparatus that minimises the temperature difference between sham and exposed conditions. Like other biological effects attributed to microwaves in the C. elegans system, phenotype shifts in ts mutants appear to be an artefact caused by very slight heating

Epidemiology of procedural pain in neonatal intensive care units of Portugal

Frequency of painful procedures, analgesia practices and related factors in neonates across neonatal intensive care units of Portugal

CO76 - Observational Study Research, Audit & Feedback, Or Benchmarking (One Of Them Or All Together?)

The potential of a research project about the epidemiology of painful procedures in neonates involving audit, feedback and benchmarking of current practices, to improve the quality of pain management

The effect of hydrogen cyanamide on bud break and yield of kiwifruit in Northwest-Portugal

Kiwifruit (Actinidia deliciosa cv. Hayward) was introduced into Northwest Portugal at the early 1970's increasing its importance up to date. The main objective of orchard management is to find out the cultural techniques suitable for the region, in order to obtain good yield and quality fruit. Winter chilling (less than or equal to7.2degreesC) plays a significant role in kiwifruit break dormancy. Insufficient chilling can be countered by chemical agents as hydrogen cyanamid (Dormex). The objective of this research was to quantify the efficiency of hydrogen cyanamide (0%, 4%, and 6%) on bud break dormancy and yield and fruit quality. Experiments were carried out over two years on a mature 'Hayward' kiwifruit orchard. The results showed that 4% Dormex was the most efficient in increasing marketable yield due to increase of flower bud formation and higher level of fruit set. There were no significant differences among treatments in soluble solids content, flesh firmness and dry weight. Titrable acidity showed higher values with increased Dormex concentration

Aromatic hydroxylation reactions by electrogenerated HO radicals : a kinetic study

The oxidation of benzoic acid (BA) and of 4-hydroxybenzoic acid (4-HBA) by galvanostatic electrolysis with simultaneous oxygen evolution, using BDD or Pt as anode materials is studied. Results concerning the oxidation kinetics as well as the identification and quantification of hydroxylated products are reported. First order kinetics are used to describe the consumption rates of both compounds despite of the anode material and of the applied current density. A simple kinetic model that accounts for the anode surface coverage by HO radicals is proposed. Based on this model it is possible to correlate the apparent rate constant of the organic consumption with kinetic parameter related to the organics reactivity and to the degree of the adsorption of HO radicals to the anode surface.FCT (Fundação para a Ciência e Tecnologia); FEDER (European Fund for Regional Development); COMPETE-QREN-EU; CQ/UM (Centro de Química / Universidade do Minho), POPH Programa Operacional Potencial Humano); FSE (Fundo Social Europeu

Electrogenerated HO radical reactions: the role of competing reactions on the degradation kinetics of hydroxy-containing aromatic compounds

The rate of degradation of some aromatic compounds, benzoic acid, 2-hydroxybenzoic acid, 4-hydroxybenzoic acid and 2,3-hydroxybenzoic acid, by electrogenerated HO radicals is investigated. The effect of the addition of secondary species, that can either be a reaction product of the target compound or not is analysed. The presence of the actual reaction products is also considered. The action of these secondary species is integrated in a general model that accounts for the dependency of the anode coverage by HO radicals on the concentration and on the reactivity of HO radical scavengers. From the magnitude of the effect of competing reactions, the reactivity of the hydroxybenzoic acid derivatives was estimated as the product between the stoichiometric coefficients and the rate constants. A possible mechanistic interpretation is provided to explain the unexpected high values of the stoichiometric coefficients estimated that largely exceed the number of radicals required for the complete mineralization of the species. (C) 2014 Elsevier Ltd. All rights reserved.- We would like to acknowledge the contribution of Prof. Paula M.T. Ferreira on the mechanistic interpretation of the HO radical stoichiometric coefficients. Thanks are due to FCT (Fundacao para a Ciencia e Tecnologia) and FEDER (European Fund for Regional Development)-COMPETE-QREN-EU for financial support to the Research Centre, CQ/UM [PEst-C/QUI/UI0686/2011 (FCOMP-01-0124-FEDER-022716)]. Raquel Oliveira thanks to FCT, POPH (Programa Operacional Potencial Humano) and FSE (Fundo Social Europeu) for the PhD Grant (SFRH/BD/64189/2009).info:eu-repo/semantics/publishedVersio

Hydroxylation of benzoic acid by electrochemical generated hydroxyl radicals

The generation of hydroxyl radicals is an important process in many applications such as organic synthesis [1], oxidative stress studies [2] and detoxification of effluents [3]. Due to the high instability of these radicals they are usually produced in situ by means of different methods, such as disproportionation of peroxynitrous acid or dissociation of hydrogen peroxide by UV action. The generation of hydroxyl radicals based on metal catalyzed decomposition of hydrogen peroxide, Fenton or Fenton-like reactions, is the most spread method. The electrochemical generation of hydroxyl radical, as an intermediate in the oxygen formation from the oxidation of water is a well-known process. The ability of boron doped diamond electrodes (BDD) to produce hydroxyl radicals is extensively described on the oxidation of organics for wastewater [4]. Although the mineralization of several electroactive species is reported, the role of hydroxyl radicals in the initial phase of these reactions is not well established. In this work we present a study on the performance of Pt and BDD anodes on the hydroxylation of benzoic acid (a non-electroactive species) comparatively to electroactive species, such as quinol and p-hydroxybenzoic acid. The reactions were monitored by fluorescence, cyclic voltammetry and HPLC (UV detection).Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BD/64189/200