Imagen ecográfica de la obstrucción biliar extrahepática en el perro : descripción de 7 casos

Se realizó un estudio ecográfico en siete perros que presentaban un cuadro de ictericia por obstrucción biliar extrahepática. Esta técnica permitió llegar al diagnóstico en seis de los casos. Se estudió la imagen ecográfica de la dilatación de las vías biliares intra y extrahepáticas, así como los signos asociados, tales como la presencia de una masa en el área pancreática, que pudiesen orientar sobre el origen de la obstrucción.An ultrasonographic examination was carried in out 7 dogs with icterus due to an extrahepatic biliary obstruction. This technique allowed the diagnosis in 6 of the dogs. The sonographic appearance of the dilated intra and extrahepatic biliary tree was assessed, as well as the associated lesions, such as the presence of a mass in the pancreatic area, which could guide towards the origin of the obstruction

El derecho político de la Segunda República

Estudio preliminar, edición y notas de Sebastián MartínVolumen en el que se editan (dos de ellas por vez primera) las memorias de cátedra de los tres principales constitucionalistas de la II República: Nicolás Pérez Serrano, Eduardo L. Llorens y Francisco Ayala. A través de dichos textos, convenientemente aclarados y ampliados por las notas del editor, los lectores pueden conocer los debates fundamentales que conformaban la disciplina del derecho político en el tiempo de entreguerras. Las memorias van precedidas por un exhaustivo estudio preliminar (pp. IX-CLXXXIX) sobre la fisonomía de aquel saber jurídico. En él se examinan la trayectoria de los profesores que impartían la asignatura; las instituciones en que se investigaba; las revistas, monografías, tratados y artículos en que circulaba; las controversias que la atravesaban; la mentalidad jurídica que de todo ello puede extraerse; y la singular aportación científica de Ayala, Llorens y Pérez Serrano, cuya obra, a juicio del prof. Martín, constituye el destilado más genuino del derecho político de la Segunda República.Este trabajo recibió una ayuda a la investigación de la Fundación Francisco Ayala y el Ministerio de Cultura. Ha sido elaborado en el marco de los proyectos de investigación DER2008-03069 y DER2010-21728-C02-0

Non-purged voltammetry explored with AGNES

The reduction of oxygen increases pH in the surroundings of an electrode. A theoretical model estimates the steady-state pH profile from the surface of the electrode up to the bulk solution. A very simple formula predicts that, in non-deareated solutions, for bulk pH-values between 4.0 and 10.0, the corresponding surface pH could be as high as 10.3, regardless of the thickness of the diffusion layer and composition of the sample (except if it has a buffering capacity). For bulk pH lower than 3.0 or higher than 10, pH increases are negligible. Less steep pH-profiles are obtained with buffers (such as MOPS 0.01 M or MES 0.01 M). The change in surface pH modifies the local speciation and hinders the standard interpretation of voltammetric responses. The electroanalytical technique Absence of Gradients and Nernstian Equilibrium Stripping (AGNES), implemented with Screen Printed Electrodes (SPE), provides experimental insights into this phenomenon. AGNES probes the free metal concentration at the electrode surface, from which the surface pH can be estimated for systems of known composition. These estimations agree with the theoretical model for the assayed systems. Additionally, the quantification of the bulk free Zn2+ and Cd2+ concentrations with specific modifications of AGNES for non-purged synthetic solutions is discussed. In general, more accurate determinations of the bulk free metal concentrations in non-purged solutions are expected: i) when the calibration is performed in a medium where the pH increase induces similar changes in the surface free metal concentration and in the sample solution and ii) when the system is more buffered.This work was financially supported by the Spanish Ministry of Education and Science (Projects CTQ2009-07831, CTM2009-14612 and CTM2012-39183), from the “Comissionat per a Universitats i Recerca del Departament d'Innovació, Universitats i Empresa de la Generalitat de Catalunya”

Free Zn2+ determination in natural freshwater of the Pyrenees: towards on-site measurements with AGNES

An on-site methodology has been developed for the direct determination of free Zn2+ with AGNES (Absence of Gradients and Nernstian Equilibrium Stripping) in freshwaters. This implementation includes: i) the use of screen printed electrodes, which provide good limits of detection and easy transportation and deployment; ii) no need for sample purging; iii) a calibration in a synthetic river solution that reproduces well the speciation changes of the natural samples and allows the oxygen interferences to be minimised; iv) the addition of a background electrolyte up to 0.01 mol L-1 in both the calibration and freshwater samples; v) chemical stripping chronopotentiometry as the quantification stage of AGNES. This procedure minimizes the effects of working at low ionic strength and in the presence of dissolved oxygen. In the laboratory, the methodology was checked with different natural samples taken from rivers Garonne, Gave de Cauterets and Gave de Pau in the Pyrenees. Results appeared in good agreement with theoretical estimations computed from Visual Minteq. On-site measurements were performed for the first time with AGNES in the Gave de Cauterets in Soulom (France) and the results were corroborated with purged measurements performed in the laboratory.English language editing by Holly Pearson is acknowledged. The authors acknowledge support for this research from the Communaut e d’Agglom eration de Pau Pyr en ees (CDAPP), from the Spanish Ministerio de Ciencia e Innovacio´n (project numbers CTM2012–39183 and CTM2013– 48967), from the European Community EFA15/08 (PyrMet) and from the Comissionat d’Universitats i Recerca de la Generalitat de Catalunya (project number 2014SGR1132)

Looking into the future: Learning services-based technological ecosystems

La gran distancia existente entre la tecnología y las metodologías docentes provoca que los nuevos avances tecnológicos no tengan fácil su integración en los contextos y prácticas metodológicas implantados, y que las tecnologías educativas maduras y los métodos educativos aplicados no respondan a las demandas de la sociedad ni al potencial transformador de la tecnología para la mejora del aprendizaje. Esta contribución plantea la necesidad de ofrecer un entorno tecnológico para el soporte de servicios de aprendizaje, el ecosistema educativo, que rompa con las limitaciones tecnológicas y de proceso de las actuales plataformas tecnológicas para conseguir una mejora de los procesos educativos. La propuesta de ecosistema educativo se concreta en 6 líneas de actuación: 1) arquitectura para la implantación de ecosistemas de servicios de aprendizaje; 2) toma de decisiones basadas en analíticas de aprendizaje; 3) sistemas de gestión de conocimiento adaptativos; 4) formación gamificada; 5) porfolios semánticos para la recogida de evidencias de aprendizaje; 6) metodologías educativas que hagan un uso efectivo de los avances tecnológicos en pro de la mejora del aprendizaje.The existing distance between technology and learning methods have two consequences: on the one hand, it makes the fit of new technological advances and existing educational methods and practices difficult; on the other hand, mature educational technologies and methods might not give an adequate answer to actual society needs and demands, and they may not fully use their transforming potential to improve learning processes. This study discusses the need for a new technological environment supporting learning services: the educational ecosystem. The educational ecosystems must be able to break the technological constraints of existing learning platforms and achieve an effective improvement of learning processes. Our proposal of educational ecosystems pivots around six specific lines of action: 1) an arquitecture that gives support to learning service-based ecosystems; 2) learning analytics for educational decision making; 3) adaptive knowledge systems; 4) gamifications; 5) semantic porfolios to collect learning evidences; 6) learning methods that make and effective use of technology for the improvement of learning processes

Radiovisiografía : nueva alternativa diagnóstica en odontoestomatología

Para el diagnóstico de diversas patologías odontológicas, la exploración de tejidos blandos y duros debe ser rigurosa. En muchas ocasiones, además de las técnicas de inspección, palpación, percusión y auscultación podemos servirnos de métodos complementarios como sondaje, aspiración, citología, biopsia, cultivos y para el diagnóstico por imagen nos valdremos de la radiología simple y de contraste. Actualmente podemos disponer de un nuevo método llamado Visiorradiología, que nos proporciona una serie de ventajas frente a la radiología convencional. En este trabajo se presenta un estudio comparativo entre la radiología simple y la visiorradiología en base al estudio de diversas piezas dentales, concluyéndose con los mejores resultados y posibilidades de la segunda con respecto a la primera en cuanto a rapidez, tratamiento de imágenes así como la posibilidad de almacenamiento en soporte magnético y control visual mediante impresora para el dueño de los animales.To diagnose some odontologic pathologies, the soft and tough tissues exploration must be strict. Sometimes, we can use complementary methods like sounding, aspiration, citology, biopsy, cultures and image diagnosis using ordinary and contrast radiology; in addition to the following techniques: examination, palpation, percution and auscultation. Actually we can have available a new method provide us advantages against the conventional radiology. In this study we present a comparative study between the simple radiology and the visiorradiology according to some tooth studies. We demonstrate that visiorradiology is beíter for the speed, images quality as well as the storing possibility . in magnetic supports and visual control trough the printer for the owner

Direct determination of free metal concentration by implementing stripping chronopotentiometry as second stage of AGNES

The electroanalytical technique Absence of Gradients and Nernstian Equilibrium Stripping (AGNES) has been extended by applying stripping chronopotentiometry (SCP) as the re-oxidation stage in the determination of the free concentration of Zn2+, Cd2+ and Pb2+. This new approach, called AGNES-SCP, has been implemented with screen-printed electrodes (SPE) and the standard Hanging Mercury Drop Electrode (HMDE). Clear advantages of this variant have been shown: (i) the easy resolution of the peaks of different metals present in mixtures and (ii) the sparing of blanks. A rigorous computation of the faradaic charge along the SCP stage takes into account the contribution of other oxidants, which can be efficiently measured at the end of the deposition stage of AGNES. The free Cd concentration determined in an oxalate solution at pH 6 with an HMDE as the working electrode agreed well with values obtained with a Cd Ion Selective Electrode. The free metal concentration measured using an SPE for the system Cd and nitrilotriacetic acid (NTA) at pH = 4.8 also conformed well with Visual MINTEQ results