Le Mormont (canton de Vaud, Suisse), lieu de culte de la fin de l’âge du Fer : résultats de la campagne de 2009-2010

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Review relationship between occupational exposure to formaldehyde and leukemia

Revisiones[ES] Introducción: El formaldehído es un cancerígeno conocido, su relación con un aumento del riesgo de leucemia en exposición ocupacional continua en debate a pesar de los diversos estudios realizados. Presentamos una revisión bibliográfica cuyo objetivo es conocer el nivel de evidencia existente entre la posible relación causal de la exposición laboral al formaldehído y la aparición de leucemia, mediante el análisis sistemático de la producción científica publicada entre los años 2008 y 2012. Metodología: Se realizó una búsqueda bibliográfica en las bases de datos Medline, IBECS, LILACS, CROCHRANE, OSH UPDATE, CISDOC, WEB OF KNOWLEDGE y SCOPUS, utilizando una estrategia de búsqueda a partir de términos “MeSH”. Se obtuvieron un total 302 artículos de los que finalmente se seleccionaron 7 que cumplían los requisitos establecidos. De ellos, 4 eran metaanálisis, 2 estudios de casos y controles, 1 estudio de cohortes. Para la asignación del nivel de evidencia se utilizaron los criterios de la Scottish Intercollegiate Guidelines Network (SIGN).Resultados: Se han encontrado riesgos elevados para los niveles de máxima exposición y también datos de mortalidad estadísticamente significativa para leucemia mieloide con aumento del número de años de prácticas de embalsamamiento. Tres metaanálisis aportan RR altos para leucemia mieloide. Un cuarto metaanálisis al excluir los estudios de mortalidad proporcional obtiene que los resultados basados en cohortes y estudios caso-control no sugieren una asociación entre exposición al formaldehído y leucemia.[EN] Background: Formaldehyde is a known carcinogen, its relationship to an increased risk of leukemia in occupational exposure continues being debated despite several studies. We present a literature review which aim is to know the level of evidence between the possible causal relationship of occupational exposure to formaldehyde and the development of leukemia, through the systematic analysis of the scientific production published from 2008 to 2012. Methods: We performed a literature search in the databases Medline, IBECS, LILACS, CROCHRANE, OSH UPDATE, CISDOC, WEB OF KNOWLEDGE and SCOPUS, using a search strategy based on terms “MeSH”. We obtained a total of 302 items, finally it were selected 7 that met all the requirements. Of these, 4 were meta-analyzes, two case-control studies and 1 cohort study. To assign the level of evidence we used the criteria of the Scottish Intercollegiate Guidelines Network (SIGN). Results: We found elevated risks for high levels of exposure and mortality data also statistically significant for myeloid leukemia with increased number of years of embalming practices. Three meta-analyzes provide high RR for myeloid leukemia. A fourth meta-analysis by excluding proportional mortality studies that the results obtained based on cohort and case-control studies do not suggest an association between formaldehyde exposure and leukemia. Discussion: The available studies have limitations that do not make it possible to establish sufficient levels of evidence confirming the conclusive relationship between formaldehyde exposure and the development of leukemia in workers. Our literature review contains heterogeneous studies in different populations ; we found values of association (RR, OR) greater than 1 in some studies and findings of chromosomal abnormalities in exposed individuals at the workplace. These data provide an interesting basis for future research about the use of accumulated internal dose biomarkers (DNA-formaldehyde adducts, Glutathione-induced DNA by formaldehyde) can better verify this association.N

COMPARATIVE ANALYTICAL DETERMINATION OF THERMAL PROTECTION BEHAVIOR FOR EXPERIMENTAL MODELS MADE OF STRATIFIED BIOCOMPOSITE BOARDS OF LIGNO-CELLULOSE NATURE

The paper addresses the comparative analytical determination of thermal insulation behavior for various experimental models made of stratified and hybrid biocomposites of ligno-cellulose nature. The analytical determination of the thermal resistance and the overall thermal insulation coefficient for each experimental model is performed using the calculation methodology for energy efficiency. The results obtained after the analysis of the thermal insulation behavior for the biocomposite panels highlighted the fact that they have thermal insulation properties with high values for thermal resistance and global thermal insulation coefficients

The Effect of Clay Type on the Physicochemical Properties of New Hydrogel Clay Nanocomposites

This study focuses on the investigation of clay type effect on the final properties of semi-interpenetrated Salecan/poly(methacrylic acid)/clay hydrogel nanocomposites. Previous studies have indicated that the presence of clay in polymer composites leads to better swelling capacity and mechanical properties as functions of clay type. On the other hand, Salecan, which is a water soluble extracellular polysaccharide, was proved to assure greater flexibility to hydrogels. These properties recommend clay and Salecan for semi-interpenetrated hydrogels preparation with specific application in biomedicine. The purpose was to determine the most suitable type of clay as well as Salecan influence for developing the desired water retention/delivery ability and mechanically enhanced semi-interpenetrating polymer network (SIPN) nanocomposites. For our investigations, we have chosen commercially available montmorillonite (ClNa) and different commercial organomodified clay (Cl30B, Cl20A and Cl15A). Several analyses results (FTIR, TGA, DMA, XRD, microscopy and swelling studies) demonstrated that not only the presence of Salecan but also the clay type influenced the structure and properties of the final nanocomposites

SOME COMPARATIVE OPINIONS REGARDING THE WORKING OF FIBERS AND MATRIX ON AXIAL STRESS LIMIT. MATRIX WITH LONGER FIBER EXTENSIONS

This paper falls within the current scientific and technical research concerns related to structures made of long fiber composite materials. An essential problem is the co-operation of the matrix material with that of the fibers in the composite layers under the action of external loads, until the structure is damaged. In the present case, the case is taken into account if the material of the matrix is characterized by elongations superior to those of the fibers, so that they will break before the damage of the matrix. The linear-elastic behavior of the fibers is considered until their rupture and, obviously, the destruction of the composite

SOME COMPARATIVE OPINIONS REGARDING THE WORKING OF FIBERS AND MATRIX ON AXIAL STRESS LIMIT. MATRIX WITH LONGER FIBER EXTENSIONS

This paper falls within the current scientific and technical research concerns related to structures made of long fiber composite materials. An essential problem is the co-operation of the matrix material with that of the fibers in the composite layers under the action of external loads, until the structure is damaged. In the present case, the case is taken into account if the material of the matrix is characterized by elongations superior to those of the fibers, so that they will break before the damage of the matrix. The linear-elastic behavior of the fibers is considered until their rupture and, obviously, the destruction of the composite

Nouvelles découvertes sur le site du Mormont (Vaud, Suisse, campagnes 2012-2015)

National audienc