The collection of furniture and decorative objects of a sevillian noblewoman: Catalina Ponce de León y Fernández de Córdoba (1629-1701)

La relación intrínseca del mueble con la vida cotidiana, así como su función ornamental dentro de la decoración de la vivienda, ha propiciado la progresiva consideración del mismo como artículo de lujo y como elemento que otorga prestigio a su propietario. La presencia de valiosas piezas de mobiliario en las colecciones reunidas por las clases acomodadas es una constante a lo largo de la Edad Moderna. En este trabajo presentamos un breve estudio de los muebles y los objetos decorativos referidos en el inventario de los bienes de la aristócrata sevillana doña Catalina Ponce de León y Fernández de Córdoba (1629-1701), realizado en 1674, como ejemplo del aprecio por el mueble como obra de arte en el siglo XVII, reflejo de un gusto artístico exquisito.The intrinsic relationship of furniture with daily life and its ornamental function in the decoration of the house has gradually led to the consideration of the first one as a luxury item and as an element which confers prestige to its owner. The presence of valuable pieces of furniture in the collections gathered by the upper classes is a constant throughout the Modern Age. In this article we present a study of the furniture and the decorative objects referred in the inventory of the properties of the Sevillian noblewoman doña Catalina Ponce de León y Fernández de Córdoba (1629-1701), conducted in 1674, as an example of the appreciation for furniture as a work of art in the seventeenth century, reflection of an exquisite artistic taste

Medidas generales en la prevención y el control del contagio hospitalario

Cartel presentado en la Segunda Conferencia Internacional de Comunicación en Salud, celebrada el 23 de octubre de 2015 en la Universidad Carlos III de MadridLa frecuencia de las infecciones hospitalarias oscila entre un 5-10% de los pacientes hospitalizados, por lo que, constituye uno de los problemas de salud pública más graves y de gran importancia epidemiológica porque aumentan las tasas de mortalidad y morbilidad, aumentan la estancia hospitalaria del paciente y con ello, los costes económicos. El objetivo de este trabajo es analizar las medidas preventivas actuales y las actuaciones para el control de dichas infecciones mediante una revisión bibliográfica. Las bases de datos requeridas para la búsqueda bibliográfica fueron: IME, SciELO, Cuiden y Dialnet, limitándose la búsqueda a publicaciones desde el año 2005 hasta la actualidad con los descriptores “infección y hospitalaria y prevención” y “infección y hospitalaria y control”. Los resultados obtenidos indican que las medidas de prevención se adecuan a la infección que se pretende evitar, pero existen métodos generales aplicables a todos los casos, como son: Correcta asepsia de las manos del personal sanitario antes y después de toda intervención realizada con el paciente; Uso de guantes propios al procedimiento; Asepsia del material en toda actuación realizada sobre el paciente; Control de los procedimientos que se le realizan a los pacientes, como: sondaje vesical, sondaje nasogástrico,…Correcta distribución, control y contacto con los pacientes; Asepsia de las dependencias hospitalarias donde están internados los pacientes. En base a los resultados obtenidos podemos concluir que para evitar las infecciones en los servicios sanitarios se cuentan con medidas que reducen satisfactoriamente la frecuencia de las mismas y que éstas deberían ser cumplidas con estricto control. La primera y más importante es la medida de prevención y la segunda es el control de la misma cuando ya está instaurada

Comparative analysis of crystallization behavior induced by different mineral fillers in polypropylene nanocomposites

A comparative analysis of crystallization behavior induced by several mineral fillers in polypropylene nanocomposites was performed. Morphological changes and thermal properties of nanocomposites were evaluated, considering the influence of shape, crystalline morphology, and concentration of mineral particles. For this study, hydrated magnesium silicates with different particle morphologies, such as platelets (talc) and fibers (sepiolite), were used for nanocomposites. In addition, to analyze the effect of mineral crystallinity on nanocomposites, talc and sepiolite from different origin and genesis were selected. Nanocomposites were compounded and injection molded, using different filler concentration (0, 1, and 3% w/w) for each mineral particle. To evaluate the particle influence on nanocomposite crystallinity, X-ray diffraction was used to determine crystalline phases and crystal orientation, meanwhile differential scanning calorimetry was performed to obtain thermal properties. Main results revealed that talc has a higher nucleating effect on polypropylene matrix than sepiolite fibers, regardless of their origin and genesis. Meanwhile, a transcrystalline layer that surrounds the fiber surface is observed for nanocomposite containing sepiolite. Moreover, Argentinean talc induces different crystalline phases in nanocomposite with respect to Australian one, which partly influences on mechanical properties.Fil: Castillo, Luciana Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería Química; ArgentinaFil: Barbosa, Silvia Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería Química; Argentin

Ferredoxinas

AbstractFerredoxins are soluble proteins that contain iron-sulfur clusters and have low redox potentials. They are present in bacteria, plants, algae and animals and function as electron carriers both in respiration and photosynthesis; and are found as: Type [2Fe-2S], Type [4Fe-4S] and Type [3Fe-4S]. Their ubiquitous presence especially in ancestral organisms has led to the idea that Fe-S proteins are very old proteins that appeared in early stages of evolution. They form a particularly versatile and useful, as well as modular and simple group of metalloproteins that achieve a vast number of functions. Here the characteristics of the different types of ferredoxins and their biological functions are discussed, together with an overview of the spectroscopic techniques employed for their study. Additionally, the result of kinetic studies of ferredoxins and inorganic compounds to learn about the reaction mechanisms are included

Study of paintability of polypropylene/talc nanocomposites

En este trabajo se propone la inclusión de partículas minerales en películas a base de polipropileno (PP) para incrementar su pintabilidad. Para tales efectos, se aplicaron diferentes clases de pinturas comerciales en aerosol sobre películas de nanocompuestos a base de PP conteniendo 0, 1 y 5% p/p de talco. El grado de cubrimiento y homogeneidad de las pinturas sobre las películas se observó mediante microscopía óptica, en tanto que la adhesión de la pintura a la superficie polimérica se evaluó mediante ensayos bajo norma ASTM. De todas las pinturas analizadas, los mejores resultados de adhesión se obtuvieron con los aerosoles para plásticos y acrílicos. Sin embargo, la presencia de las nanopartículas de talco indujo mejoras en la adhesión pintura-película para el caso de los aerosoles que no son apropiados para aplicar sobre superficies plásticas, tal es el caso de los de secado rápido y para melamina.In this work the incorporation of mineral particles in films based on polypropylene (PP) to increase their paintability, is proposed. For this purpose, several kinds of commercial spray paints were applied on nanocomposite films based on PP containing 0, 1 and 5% w/w of talc. The coating degree and homogeneity of the paints on the films was observed by optical microscopy, meanwhile the paint adhesion to the polymeric surface was evaluated using ASTM standard tests. From all analyzed paints, the best adhesion results were obtained with sprays for plastics and acrylics. However, the presence of talc nanoparticles induced improvements on paint-film adhesion for spray paints that are not suitable for application on plastic surfaces, such as quick dry and melamine paints.Fil: Amaya, Tomás. Universidad Nacional del Sur. Departamento de Ingeniería Química; ArgentinaFil: Castillo, Luciana Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; ArgentinaFil: Barbosa, Silvia Elena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentin

Theoretical studies of the hydrolysis of antibiotics catalyzed by a metallo-B-lactamase

In this paper, hybrid QM/MM molecular dynamics (MD) simulations have been performed to explore the mechanisms of hydrolysis of two antibiotics, Imipenen (IMI), an antibiotic belonging to the subgroup of carbapenems, and the Cefotaxime (CEF), a third-generation cephalosporin antibiotic, in the active site of a mono-nuclear β- lactamase, CphA from Aeromonas hydrophila. According to our results, significant different transition state structures are obtained for the hydrolysis of both antibiotics: while the TS of the CEF is a ionic species with negative charge on nitrogen, the IMI TS presents a tetrahedral-like character with negative charge on oxygen atom of the carbonyl group of the lactam ring. Thus, dramatic conformational changes can take place in the cavity of CphA to accommodate different substrates, which would be the origin of its substrate promiscuity. This feature of the β-lactamase would be in turn, associated to the different mechanisms that the protein employs to hydrolyze the different antibiotics; i.e. the catalytic promiscuity. Since CphA shows only activity against carbapenem antibiotic, this study will be used to shed some light into the origin of the selectivity of the different MbL and, as a consequence, into the discovery of specific and potent MβL inhibitors against a broad spectrum of bacterial pathogens.We thank FEDER and the Spanish Ministerio de Economía y Competitividad (project CTQ2012-36253-C03), Universitat Jaume I (project P1 1B2011-23) and Generalitat Valenciana (PROMETEOII/2014/022 and ACOMP/2014/277 projects

QM/MM Calculations Suggest a Novel Intermediate Following the Proton Abstraction Catalyzed by Thymidylate Synthase

The cleavage of covalent C–H bonds is one of the most energetically demanding, yet biologically essential, chemical transformations. Two C–H bond cleavages are involved in the reaction catalyzed by thymidylate synthase (TSase), which provides the sole de novo source of thymidylate (i.e., the DNA base T) for most organisms. Our QM/MM free energy calculations show that the C–H → O proton transfer has three transition states that are energetically similar but structurally diverse. These characteristics are different from our previous calculation results on the C–H → C hydride transfer, providing an explanation for differences in temperature dependences of KIEs on these two C–H bond activation steps. The calculations also suggest that the traditionally proposed covalent bond between the protein and substrate (the C6–S bond) is very labile during the multistep catalytic reaction. Collective protein motions not only assist cleavage of the C6–S bond to stabilize the transition state of the proton transfer step but also rearrange the H-bond network at the end of this step to prepare the active site for subsequent chemical steps. These computational results illustrate functionalities of specific protein residues that reconcile many previous experimental observations and provide guidance for future experiments to examine the proposed mechanisms. The synchronized conformational changes in the protein and ligands observed in our simulations demonstrate participation of protein motions in the reaction coordinate of enzymatic reactions. Our computational findings suggest the existence of new reaction intermediates not covalently bound to TSase, which may lead to a new class of drugs targeting DNA biosynthesis