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Porosity dependence of electron percolation in nanoporus TiO2 layers

  • Bisquert, Juan
  • Ofir, Ashi
  • Dor, Snir
  • Grinis, Larisa
  • Zaban, Arie
  • Dittrich, Thomas
The electron diffusion coefficient at varying porosity has been determined in a series of nanostructured TiO2 films of different initial thicknesses. The porosity was changed by applying different pressures prior to sintering, thereby modifying the internal morphology of the films though not their chemical and surface conditions. A systematic increase of the effective diffusion coefficient was observed as the porosity was decreased, indicating the improvement of the internal connectivity of the network of nanoparticles. The experimental results have been rationalized using percolation theory. First of all, applying a power law dependence, the diffusion coefficient as a function of porosity from different films collapsed in a single master curve. In addition, application of the models of effective medium approximation EMA allows us to compare the experimental results with previous data from Monte Carlo simulation. The different data show a similar dependence in agreement with the EMA predictions, indicating that the geometrical effect of electron transport due to variation of porous morphology in TiO2 nanoparticulate networks is well described by the percolation concept
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Base Supported Ionic Liquid-Like Phases as catalysts for the Batch and Continuous-Flow Henry Reaction

  • Garcia-Verdugo, Eduardo
  • Erythropel, Hanno
  • Burguete, M. Isabel
  • Sans, Victor
  • Luis Lafuente, Santiago Vicente
New solid basic catalysts immobilised onto supported ionic liquid-like phases have been prepared, having suitable mechanical stability for their use for the continuous-flow Henry reaction
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Photonic and Nanobiophotonic Properties of Luminescent Lanthanide-Doped Hybrid Organic-Inorganic Materials

  • Planelles Aragó, José
  • Julian-Lopez, Beatriz
  • Escribano López, Purificación
  • Viana, Bruno
  • Cordoncillo, Eloisa
  • Sánchez, Clément
Research into lanthanide-doped organic–inorganic hybrid materials emerged in the 1990s with the development of interesting materials for optics: high efficiency and stable solid-state lasers, new fiber amplifiers and sensors, devices with upconversion, fast photochromic and non-linear responses, etc. Their interest relies on the possibility of combining properties of sol–gel host materials (shaping, tunable refractive index and mechanical properties, corrosion protection, specific adhesion, etc.) and the well-known luminescence of lanthanide ions (Ln). The fast development of photonic hybrids allowed the commercial exploitation of products with new or enhanced characteristics (megajoule pulsed Nd-YAG laser, protective coatings of glasses, screens or glasswares). However, recently, Ln-hybrid nanocomposites have found new applications in bio-sensors, bio-analytics and even clinical imaging diagnostics. These applications make use of the fluorescence properties of lanthanides that make luminescent hybrids ideal candidates for time-resolved fluoroimmunoassays, DNA hybridation assays, fluorescence imaging microscopy, or in vivo imaging. As a consequence, the goal of this review is twofold: (i) as a reminder of some general considerations that must be taken into account to design new optically active Ln-doped nanocomposites whatever the application field, and (ii) to show the most important advances achieved in the past years in different areas, paying special attention to bio-medical applications
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La senda revolucionaria del liberalismo doceañista en España y México

  • Frasquet, Ivana
En este estudio intentamos abordar la significación del liberalismo doceañista en la transformación de la monarquía hispánica y su trascendencia en la construcción del Estado-nación mexicano a partir de 1821. Para ello interpretamos desde la metodología histórica la noción de «liberalismo doceañista» al tiempo que argumentamos su importancia en los debates del congreso constituyente mexicano de 1822
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Escenografía virtual en TV. Análisis del uso de la escenografía virtual en la realización de un programa de televisión, Virtual set on television. Analysis of the use of virtual set in the realization of a TV program

  • Galán Cubillo, Esteban
La escenografía virtual es un fenómeno muy reciente que surge en la década de los 90’ como una aplicación de la realidad virtual al ámbito televisivo. En este artículo se analiza cómo la escenografía virtual modifica el proceso de realización televisiva afectando a sus diferentes fases de preproducción, producción y postproducción de un programa de televisión. Esta investigación se ha llevado a cabo contemplando las repercusiones a nivel tecnológico, creativo y económico que ofrece el uso de esta tecnología. El trabajo de campo que se ha empleado para llevar a cabo este análisis ha consistido en cuestionarios on line y entrevistas en profundidad a los profesionales que trabajan con escenografía virtual en España en televisiones públicas y privadas de cobertura nacional y autonómica, The virtual studio is a very recent phenomenon that emerged in the mid-90 'as an application of virtual reality to the television field. This article examines how virtual studio amending process of realizing television affecting their various stages of pre-production, production and post-production of a television program. This research has been carried out considering the impact in technology, creative and economic offered by the use of this technology. The field work that has been used to carry out this analysis has been on-line questionnaires and in-depth interviews with professionals who work with virtual scenery in Spain in public and private television channels with national and regional coverage
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El liderazgo upstream vs. downstream en la determinación de la estructura vertical de mercado

  • García-Gallego, Aurora
  • Camacho Cuena, Eva
En un modelo en el que dos marcas diferenciadas verticalmente pueden ser distribuidas por hasta dos minoristas potencialmente diferenciados, estudiamos la estructura distributiva del mercado en equilibrio resultante de la decisión de los minoristas o los productores. En términos de bienestar social, las estructuras de distribución de equilibrio decididas por los productores dominan débilmente a las resultantes de decisiones de los minoristas. Contrariamente a la preocupación habitual sobre el poder de mercado en el segmento upstream, nuestros resultados sugieren que la elección de la estructura de distribución por parte de minoristas con poder puede, per se, ser la causa de estructuras verticales socialmente ineficientes, In a model in which two vertically differentiated brands can be distributed by up to two potentially differentiated retailers, we study the equilibrium distribution market structure resulting from the decision of retailers or manufacturers. In terms of social welfare, equilibrium distribution structures decided by producers weakly dominate those resulting from retailers’ decisions. Contrary to usual concerns about upstream market power, our results suggest that the choice of the distribution structure by powerful retailers may be, per se, the cause of socially inefficient vertical structures
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El papel de los rendimientos y la diferenciación de productos como determinantes de la estabilidad del cártel

  • Georgantzis, Nikolaos
  • Contreras Marín, Roberto
  • Ginés Vilar, Miguel
Estudiamos las implicaciones que tienen sobre la estabilidad del cártel, los rendimientos de la producción en presencia de productos diferenciados, cuando las empresas compiten en cantidades. Mostramos que el cártel puede ser igualmente estable en presencia de un menor grado de diferenciación siempre que las deseconomías de escala sean mayores. Además demostramos que a partir de un determinado factor de descuento pueden existir tecnologías con rendimientos de escala constantes o decrecientes donde el cártel siempre es estable independiente del grado de diferenciación, We study cartel stability in a differentiated quantity-setting duopoly with decreasing returns to scale. We show that a cartel may be equally stable in the presence of lower differentiation, provided that the decreasing returns parameter is higher. Furthermore, we show that, above a given discount rate, a cartel may be stable for any degree of product differentiation
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Duelo: evaluación, diagnóstico y tratamiento

  • Gil Juliá, Beatriz
  • Bellver, Ascensión
  • Ballester-Arnal, Rafael
A lo largo de la vida, todos los seres humanos sufren en mayor o menor medida el duelo por una pérdida. Es una experiencia inevitable que conlleva sufrimiento pero también puede ser una oportunidad de crecimiento. Objetivo: realizar una revisión bibliográfi - ca tanto de los artículos publicados durante los últimos años sobre estudios relacionados con el duelo, como de los aspectos más relevantes contenidos en la literatura reciente. Material y método: las referencias bibliográfi cas en las que nos hemos basado han sido recogidas de las bases computerizadas Medline y PsycINFO, siendo la mayoría de los artículos encontrados de procedencia anglosajona; además se han consultado las principales revistas españolas relacionadas con el tema. Resultados: en función del contenido de los resultados, hemos tratado de organizar el trabajo en las siguientes áreas: evaluación del duelo; diagnóstico de duelo complicado; predictores de duelo patológico; prevención y tratamiento. Conclusiones: la mayoría de estudios encontrados sobre el duelo son descriptivos, en cambio hay pocos estudios con un diseño experimental adecuado. No obstante, consideramos que es necesario investigar más sobre los aspectos fundamentales de esta compleja realidad, Throughout their life, all human beings suffer in greater or lesser extent the grief due to a loss. It is an inevitable experience which causes suffering, but it also can be an opportunity for growth. Objectives: with this study our goal is to conduct a bibliographical review both of the articles published over the last few years of studies related with bereavement, as well as of the most relevant details contained in recent literature. Materials and methods: the bibliographical references on which we have based our research have been gathered from Medline and PsycINFO computerized databases. The majority of the articles are of Anglo-Saxon origin and noteworthy Spanish journals related with the topic have also been consulted. Results: according to the content of the results, we have tried to organize the study in the following areas: evaluation of grief; diagnosis of complicated bereavement; predictors of pathological bereavement, prevention and treatment. Conclusions: the majority of the studies found on bereavement are descriptive; however, there are few studies with an adequate experimental design. Nevertheless, we believe that it is necessary to further investigate the fundamental aspects of this complex reality
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Assessment of disease named entity recognition on a corupus of annotated sentences

  • Jiménez Ruiz, Ernesto
  • Jimeno Yepes, Antonio José
  • Lee, Vivian
  • Gaudan, Sylvain
  • Berlanga Llavori, Rafael
  • Rebholz-Schuhmann, Dietrich
Background: In recent years, the recognition of semantic types from the biomedical scientific literature has been focused on named entities like protein and gene names (PGNs) and gene ontology terms (GO terms). Other semantic types like diseases have not received the same level of attention. Different solutions have been proposed to identify disease named entities in the scientific literature. While matching the terminology with language patterns suffers from low recall (e.g., Whatizit) other solutions make use of morpho-syntactic features to better cover the full scope of terminological variability (e.g., MetaMap). Currently, MetaMap that is provided from the National Library of Medicine (NLM) is the state of the art solution for the annotation of concepts from UMLS (Unified Medical Language System) in the literature. Nonetheless, its performance has not yet been assessed on an annotated corpus. In addition, little effort has been invested so far to generate an annotated dataset that links disease entities in text to disease entries in a database, thesaurus or ontology and that could serve as a gold standard to benchmark text mining solutions. Results: As part of our research work, we have taken a corpus that has been delivered in the past for the identification of associations of genes to diseases based on the UMLS Metathesaurus and we have reprocessed and re-annotated the corpus. We have gathered annotations for disease entities from two curators, analyzed their disagreement (0.51 in the kappa-statistic) and composed a single annotated corpus for public use. Thereafter, three solutions for disease named entity recognition including MetaMap have been applied to the corpus to automatically annotate it with UMLS Metathesaurus concepts. The resulting annotations have been benchmarked to compare their performance. Conclusions: The annotated corpus is publicly available at ftp://ftp.ebi.ac.uk/pub/software/textmining/corpora/diseases and can serve as a benchmark to other systems. In addition, we found that dictionary look-up already provides competitive results indicating that the use of disease terminology is highly standardized throughout the terminologies and the literature. MetaMap generates precise results at the expense of insufficient recall while our statistical method obtains better recall at a lower precision rate. Even better results in terms of precision are achieved by combining at least two of the three methods leading, but this approach again lowers recall. Altogether, our analysis gives a better understanding of the complexity of disease annotations in the literature. MetaMap and the dictionary based approach are available through the Whatizit web service infrastructure (Rebholz-Schuhmann D, Arregui M, Gaudan S, Kirsch H, Jimeno A: Text processing through Web services: Calling Whatizit. Bioinformatics 2008, 24:296-298)
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QM/MM simulations for methyl transfer in solution and catalysed by COMT: ensemble-averaging of kinetic isotope effects

  • Kanaan Izquierdo, Natalia
  • Ruiz-Pernía, José Javier
  • Williams, Ian H.
Sampling of structures from QM/MM molecular dynamics reveals distinct families of reactant-state conformers and yields kinetic isotope effects for reactions in enzyme active sites and in solution, averaged over thermal fluctuations of the environment, that allows meaningful comparison of computed with experimental values
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