Étude radiolytique de la capture de radicaux peroxyles modèles par un analogue de vitamine E

La vitamine E constitue biologiquement l'ultime barrière de défense contre les phénomènes de peroxydation au sein des membranes lipidiques. Cette action antioxydante est due à la capture de radicaux peroxyles issus des acides gras insaturés. Les différentes étapes d'oxydation monoélectronique ont été étudiées par la méthode de la radiolyse continue, la vitamine E étant en solution éthanolique aérée. De manière analogue, la capture de radicaux peroxyles modèles par une molécule dérivée de la vitamine E a été caractérisée, tant sous l'aspect qualitatif que quantitatif

PHOTOCATALYTIC OXIDATION OF CYCLOHEXANE BY (nBu4N)4W10O32/Fe(III)PORPHYRINS INTEGRATED SYSTEMS

The oxidation of cyclohexane by photoexcited (nBu4N)W10O32 has been investigated in the presence of iron-meso-tetraarylporphyrins bearing different substituents in the beta-pyrrole positions and/or in the meso-aryl groups

Evaluation of Burnout Syndrome in Medical Residents Following a “Rest After Shift” Intervention

Background: The burnout syndrome generates a negative impact on professional performance, patients safety and residents life. Despite this problem has become important in the residency programs in Argentina, the effective measures to prevent burnout among residents have not been evaluated yet. Objective: The aim of this study is to evaluate the prevalence of the burnout syndrome before and after the implementation of rest after shift in cardiology residents. Methods: We conducted an analytic and prospective study. The Maslach burnout inventory was used in cardiology residents in an institution in the city of Buenos Aires, before and after the implementation of a day of rest (DOR) after a 24-hour duty shift. Results: The survey was responded by 42 residents (2014: 19; 2015: 23). There was a trend toward lower prevalence of burnout in the DOR group (26.1% vs. 47.4% p = 0.152) and better outcomes in the subscale depersonalization [19 (11-21) vs. 10 (1-17) p=0.023]. Women and residents who have moved to Buenos Aires presented lower degrees of exhaustion and depersonalization. Conclusions: The implementation of the DOR after a 24-hour duty shift was associated with a reduction in the scale depersonalization, particularly among women. We emphasize the importance of creating prevention strategies aimed at improving residents’ working conditions and quality of life.Introducción: El síndrome de Burnout hace referencia al desgaste emocional y físico secundario al estrés crónico laboral. Genera impacto negativo en la actuación profesional,  seguridad del paciente, la vida social del residente. Esta problemática ha tomado vigencia en las residencias médicas argentinas, sin embargo no se han evaluado medidas efectivas para prevenir su aparición. Objetivo: Evaluar y comparar la prevalencia del síndrome de burnout antes y después a la implementación del descanso post guardia en médicos residentes de cardiología clínica. Materiales y métodos: Estudio observacional analítico, prospectivo. Se implementó el cuestionario de Maslach en residentes de cardiología de una institución de la ciudad de Buenos Aires, antes y después de la implementación de un período de descanso de 24 hs. luego de una guardia de 24hs. Resultados: La encuesta fue respondida por 42 residentes (2014: 19; 2015: 23). Hubo una tendencia no significativa a menor prevalencia de Burnout en el grupo con descanso post guardia que sin descanso (26.1% vs 47.4% p =0.152) y además presentaron mejores resultados en la escala de despersonalización (19 [11-21] vs 10 [1-17] p = 0.023). Las mujeres presentaron menor agotamiento y despersonalización que los hombres Conclusiones: La implementación del DPG se asoció a la reducción de la escala de despersonalización, principalmente en mujeres. Esta investigación remarca la importancia de crear estrategias de prevención que mejoren las condiciones de trabajo, la calidad de vida y de aprendizaje del residente

PHOTOREDOX AND PHOTOCATALYTIC PROCESSES ON Fe(III)PORPHYRIN SURFACE MODIFIED NANOCRYSTALLINE TiO2

Surface derivatization of titanium dioxide nanoparticles with a Fe(III)-porphyrin has been carried out following a new procedure whereby the complex, rather than the surface, contains the aminopropylsilane functional group. Characterization of the light trasparent dispersions by laser flash photolysis, UV-vis spectroscopy and photoelectrochemical methods has shown that the nature of the solvent is an imporetant parameter in determining the redox processes involving the grafted porphyrin. The photocatalytic activity of the composite system was assessed in the process of monooxygenation of cyclohexane and cyclohexene by molecular oxygen

BIOMIMETIC PHOTOCATALYSIS: IRON PORPHYRINS IN OXYGEN ACTIVATION PROCESSES

An intramoleculr electron transfer can occur in iron porphyrin complexes when irradiated with light of wavelengths correspondign to axial ligand-to metal charge transfer transitions. This initiates the biomimetic activation of O2

Iron meso-tetra(2,6-dichlorophenyl)porphyrin as a very efficient catalyst for the photoreduction of carbon tetrachloride by alcohols.

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Oxidation of alkanes by dioxygen catalyzed by photoactivated iron porphyrins.

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