591 research outputs found

    Energía y productos de hidrólisis a partir de cultivos industriales y forestales

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    Se caracterizan química y energéticamente diversas especiesvegetales de elevada producción de biomasa (Eucalyptus globulus, tallos de girasol, Chamaecitysus proliferus, Paulownia fortunei, Leucaena diversifolia y Arundo donax) y se estudia el proceso de autohidrólisis en condiciones no isotermas en un marco general de evaluación de la valorización por fraccionamiento y aprovechamiento integral de las fracciones lignocelulósicas con posterior aprovechamiento energético de la fase sólida post-hidrólisis. Los procesos de autohidrólisis se han revelado particularmente interesantes en el caso de las especies madereras estudiadas frente a las especies herbáceas con variaciones en la extracción de la fracción de xilano a 180ºC entre el 19,7% de Eucalyptus globulus y el 36,8% de Leucaenadiversifolia y a 200ºC entre el 57,9% de Paulownia fortunei y el 79,1% de Chamaecytisus proliferus. Las especies madereras de corta rotación de cultivo ensayadas se manifiestan más susceptibles que la especie de referencia (Eucalyptus globulus) al proceso de autohidrólisis a bajas temperaturas. La explotación de las especies madereras de corta rotación ensayadas por combustión directa de la fracción sólida post-autohidrólisis a 200ºC aporta, además de la valorización inherente a los oligómeros y monosacáridos de la fracción líquida, un aumento del poder calorífico relativo de la fracción sólida post-autohidrólisis del 3,4% en Paulownia fortunei y 6,7% en Leucaena diversifolia

    What are microRNAs? Potential biomarkers and therapeutic targets in osteoporosis

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    Los micro-ARN (miRs) son pequeñas moléculas de ARN no codificantes que regulan la expresión génica a nivel post-transcripcional. Generalmente actúan sobre la expresión genética mediante el silenciamiento o degradación de los ARNm, y están implicados en la regulación de varios procesos biológicos, como la diferenciación celular, la proliferación, la apoptosis y en el desarrollo embrionario y tisular. Actualmente son un importante foco de interés para el estudio de diversas enfermedades como el cáncer o la diabetes mellitus tipo 2. A nivel del metabolismo óseo, están surgiendo diversos miRs implicados en su regulación, abriendo un campo de investigación importante para identificar nuevos biomarcadores para el diagnóstico de la enfermedad osteoporótica, de su evolución, así como para diseñar nuevas terapias farmacológicas.Micro-RNAs (miRs) are small non-coding RNA molecules that regulate gene expression at post-transcriptional level. Generally, they act on gene expression by silencing or degrading mRNAs, and are involved in regulating various biological processes, such as cell differentiation, proliferation, apoptosis and in embryonic and tissue development. They are currently a major focus of interest in the study of various diseases such as cancer or type 2 diabetes mellitus. At level of bone metabolism, various miRs are emerging that are involved in their regulation, opening an important research field to identify new biomarkers for diagnosis of osteoporosis and its development, and to design new drug therapies

    Revealing hidden clonal complexity in Mycobacterium tuberculosis infection by qualitative and quantitative improvement of sampling

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    AbstractThe analysis of microevolution events, its functional relevance and impact on molecular epidemiology strategies, constitutes one of the most challenging aspects of the study of clonal complexity in infection by Mycobacterium tuberculosis. In this study, we retrospectively evaluated whether two improved sampling schemes could provide access to the clonal complexity that is undetected by the current standards (analysis of one isolate from one sputum). We evaluated in 48 patients the analysis by mycobacterial interspersed repetitive unit–variable number tandem repeat of M. tuberculosis isolates cultured from bronchial aspirate (BAS) or bronchoalveolar lavage (BAL) and, in another 16 cases, the analysis of a higher number of isolates from independent sputum samples. Analysis of the isolates from BAS/BAL specimens revealed clonal complexity in a very high proportion of cases (5/48); in most of these cases, complexity was not detected when the isolates from sputum samples were analysed. Systematic analysis of isolates from multiple sputum samples also improved the detection of clonal complexity. We found coexisting clonal variants in two of 16 cases that would have gone undetected in the analysis of the isolate from a single sputum specimen. Our results suggest that analysis of isolates from BAS/BAL specimens is highly efficient for recording the true clonal composition of M. tuberculosis in the lungs. When these samples are not available, we recommend increasing the number of isolates from independent sputum specimens, because they might not harbour the same pool of bacteria. Our data suggest that the degree of clonal complexity in tuberculosis has been underestimated because of the deficiencies inherent in a simplified procedure

    Rasgos de personalidad y burnout en médicos de familia

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    ObjetivoInvestigar los rasgos de personalidad que podrían asociarse con puntuaciones altas en las escalas de burnout (Maslach Burnout Inventory) en médicos de atención primaria.DiseñoEstudio observacional, descriptivo, transversal.EmplazamientoNoventa y tres centros de atención primaria de la ciudad de Barcelona y las comarcas del norte de la provincia: Vallès Oriental, Vallès Occidental, Maresme, Osona, Bages y Berguedà (región sanitaria centro).MétodoEncuesta directa por entrevista personal o grupal a 528 médicos de atención primaria. Se administraron 3 cuestionarios: uno de datos sociodemográficos generales, el Maslasch Burnout Inventory (MBI) y el test de personalidad de Cattell 16 PF-5.ResultadosUn 40% de los encuestados presentaba algún síntoma de burnout sin diferencia entre sexos. De éstos, un 12,4% manifestaba niveles muy altos de «quemazón» profesional. Los sujetos con criterios de burnout obtuvieron puntuaciones significativamente diferentes en los rasgos de estabilidad, tensión y vigilancia y en la dimensión ansiedad.ConclusionesAlgunos rasgos de personalidad, como la baja estabilidad emocional, la tensión y la ansiedad, se asocian de manera significativa a puntuaciones altas de burnoutExisten algunas diferencias entre estos factores internos por sexo.ObjectiveWith this research we try to study personality traits that could be associated with high punctuation at burnout scales (Maslach Burnout Inventory) in primary care physicians.DesignObservational descriptive transversal studySetting93 primary care centres in Barcelona-city and the northern province's region: Vallès Oriental, Vallès Occidental, Maresme, Osona, Bages and Berguedà (centre sanitary region).MethodIndividual or collective direct interview to 528 primary care physicians. Three questioners were administrated: a sociodemographyc items one, the Maslach Burnout Inventory (MBI) and the Cattell personality test 16-PF.ResultsThe 40% of the interviewed physicians had some burnout symptom without any difference between sexes. The 12.4% of these ones showed very high burnout levels. Those subjects with burnout criteria punctuated different at stability, tension and vigilance traits and anxiety dimension.ConclusionSome personality traits like low stability, the tension and the anxiety are associated with high punctuation of burnout

    Collusion detection in public procurement auctions with machine learning algorithms

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    Collusion is an illegal practice by which some competing companies secretly agree on the prices (bids) they will submit to a future auction. Worldwide, collusion is a pervasive phenomenon in public sector procurement. It undermines the benefits of a competitive marketplace and wastes taxpayers' money. More often than not, contracting authorities cannot identify non-competitive bids and frequently award contracts at higher prices than they would have in collusion's absence. This paper tests the accuracy of eleven Machine Learning (ML) algorithms for detecting collusion using collusive datasets obtained from Brazil, Italy, Japan, Switzerland and the United States. While the use of ML in public procurement remains largely unexplored, its potential use to identify collusion are promising. ML algorithms are quite information-intensive (they need a substantial number of historical auctions to be calibrated), but they are also highly flexible tools, producing reasonable detection rates even with a minimal amount of information
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