566 research outputs found

    Biodisponibilidad. Concepto y cuantificación. Aplicación a emplazamientos contaminados con hidrocarburos policíclicos aromáticos

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    39 páginas.-- 25 figuras.-- 2 tablas.-- 36 referencias. Memoria del XL Curso Internacional de Edafología y Biología Vegetal, 2003Director del trabajo: Ortega Calvo, J. J.La presencia de contaminantes en la naturaleza representa una amenanza para la salud humana y para los ecosistemas. En este sentido es importante tener presente que la mencionada amenaza depende dedos factores relativamente independientes entre si; por una parte de la toxicidad de la sustancia en si misma y por otra de la probabilidad de que la sustancia en cuestión pueda entrar en contacto con la población que se ve amenazada, lo que puede tener lugar mediante el transporte del mismo en cualquiera de las fases móviles que constituyen el entorno, o mediante el contacto directo con el contaminante. El riesgo asociado a la presencia de estas sustancias en medios como el aire o el agua se cuantifica, normalmente, a través de la medida de su concentración en dichos medios y de modelos que representan los fenómenos que tienen lugar durante su transporte: dispersión, dilución, degradación, etc. A pesar de la complejidad de estos modelos, resultan considerablemente más simples que los necesarios para representar otros compartimentos del medio ambiente, como el suelo o los sedimentos.Peer reviewe

    Allelic and phenotypic characterization of CYP2D6 and its encoded P450 cytochrome enzyme in a serie of Spanish type 1 Gaucher disease patients

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    Background: Cytochrome p450 is the main drug metabolic pathway. CYP2D6 is a highly polymorphic gene that encodes a cytochrome p450 enzyme with three activity levels: null, reduced and normal. Apart from another type of mutations CYP2D6 can suffer duplications and deletions of the entire gene. This is the pathway to metabolize one of the Gaucher disease treatments, whose dose administration is regulated according to the metabolizer phenotype, this being one of the administration limitations. Objectives: The aim of this paper is to evaluate the allelic frequencies and the metabolizer status of Gaucher type 1 patients in the Spanish population and compare it with the general Spanish population and other Gaucher disease groups. Methods: In this study, 109 type 1 Gaucher disease patients were analyzed with the xTAG®CYP2D6 kit to identify the CYP2D6 gene alleles. Results: We observed that eighty-seven patients could be classified as extensive, 14 as intermediate, 6 as poor and 2 as ultra-rapid metabolizers. The allelic duplication frequency is 5.5% and deletion is 4.5%. The most common allele is wild-type and the second is the null *4 allele. Intermediate phenotype frequency is higher than expected (p < 0.05). Conclusions: Our Spanish GD series shows an unexpected distribution of some alleles and phenotypic metabolizer status, in contrast to that previously reported in the Spanish population

    Submicronic Filtering Media Based on Electrospun Recycled PET Nanofibers: Development, Characterization, and Method to Manufacture Surgical Masks

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    The disposal of single-use personal protective equipment has brought a notable environmental impact in the context of the COVID-19 pandemic. During these last two years, part of the global research efforts has been focused on preventing contagion using nanotechnology. This work explores the production of filter materials with electrohydrodynamic techniques using recycled polyethylene terephthalate (PET). PET was chosen because it is one of the materials most commonly present in everyday waste (such as in food packaging, bags, or bottles), being the most frequently used thermoplastic polymer in the world. The influence of the electrospinning parameters on the filtering capacity of the resulting fabric was analyzed against both aerosolized submicron particles and microparticulated matter. Finally, we present a new scalable and straightforward method for manufacturing surgical masks by electrospinning and we validate their performance by simulating the standard conditions to which they are subjected to during use. The masks were successfully reprocessed to ensure that the proposed method is able to reduce the environmental impact of disposable face masks. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

    The Entropy of Laughter: Discriminative Power of Laughter’s Entropy in the Diagnosis of Depression

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    Laughter is increasingly present in biomedical literature, both in analytical neurological aspects and in applied therapeutic fields. The present paper, bridging between the analytical and the applied, explores the potential of a relevant variable of laughter’s acoustic signature—entropy—in the detection of a widespread mental disorder, depression, as well as in gauging the severity of its diagnostic. In laughter, the Shannon–Wiener entropy of the distribution of sound frequencies, which is one of the key features distinguishing its acoustic signal from the utterances of spoken language, has not been a specific focus of research yet, although the studies of human language and of animal communication have pointed out that entropy is a very important factor regarding the vocal/acoustic expression of emotions. As the experimental survey of laughter in depression herein undertaken shows, it was possible to discriminate between patients and controls with an 82.1% accuracy just by using laughter’s entropy and by applying the decision tree procedure. These experimental results, discussed in the light of the current research on laughter, point to the relevance of entropy in the spontaneous bona fide extroversion of mental states toward other individuals, as the signal of laughter seems to imply. This is in line with recent theoretical approaches that rely on the optimization of a neuro-informational free energy (and associated entropy) as the main “stuff” of brain processing

    4D-Var Assimilation of MIPAS chemical observations: ozone and nitrogen dioxide analyses

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    International audienceThis paper discusses the global analyses of stratospheric ozone (O3) and nitrogen dioxide (NO2) obtained by the Belgian Assimilation System for Chemical Observations from Envisat (BASCOE). Based on a chemistry transport model (CTM) and the 4-dimensional variational (4D-Var) method, BASCOE has assimilated chemical observations of O3, NO2, HNO3, N2O, CH4 and H2O, made between July 2002 and March 2004 by the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) onboard the European Space Agency (ESA) Environment Satellite (ENVISAT). This corresponds to the entire period during which MIPAS was operating at its nominal resolution. Our analyses are evaluated against assimilated MIPAS data and independent HALOE (HALogen Occultation Experiment) and POAM-III (Polar Ozone and Aerosol Measurement) satellite data. A good agreement is generally found between the analyses and these datasets, in both cases within the estimated error bars of the observations. The benefit of data assimilation is also evaluated using a BASCOE free model run. For O3, the gain from the assimilation is significant during ozone hole conditions, and in the lower stratosphere. Elsewhere, the free model run is within the MIPAS uncertainties and the assimilation does not provide significant improvement. For NO2, the gain from the assimilation is realized through most of the stratosphere. Using the BASCOE analyses, we estimate the differences between MIPAS data and independent data from HALOE and POAM-III, and find results close to those obtained by classical validation methods involving only direct measurement-to-measurement comparisons. Our results extend and reinforce previous MIPAS data validation efforts by taking account of a much larger variety of atmospheric states and measurement conditions. This study discusses possible further developments of the BASCOE data assimilation system; these concern the horizontal resolution, a better filtering of NO2 observations, and the photolysis calculation near the lid of the model. The ozone analyses are publicly available via the PROMOTE project http://www.gse-promote.org)
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