226 research outputs found

    Casos de innovaciĂłn en salud en Colombia: retos y proyectos

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    A continuación conoceremos los inicios, experiencias y expectativas de un par de jóvenes colombianos, profesionales en salud que en la actualidad trabajan en el desarrollo de tecnologías biomédicas para poblaciones vulnerables y que apoyan la gestión de programas institucionales para identificar, apoyar y motivar la implementación de éstas dentro del sistema de salud. Aclaramos que los textos de soporte y preguntas desarrolladas por la Revista Ingeniería Biomédica (RIB) y las respuestas brindadas no representan necesariamente las ideas e intereses de las instituciones involucradas

    Reversible Tuning of Ca Nanoparticles Embedded in a Superionic CaF2 Matrix

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    ABSTRACT: Controlling the size and shape of metallic colloids is crucial for a number of nanotechnological applications ranging from medical diagnosis to electronics. Yet, achieving tunability of morphological changes at the nanoscale is technically difficult and the structural modifications made on nanoparticles generally are irreversible. Here, we present a simple non-chemical method for controlling the size of metallic colloids in a reversible manner. Our strategy consists on applying hydrostatic pressure on a Ca cationic sublattice embedded in the irradiated matrix of CaF2 containing a large concentration of defects. Application of our method to CaF2 along with in situ optical absorption of the Ca plasmon shows that the radii of the Ca nanoparticles can be reduced with an almost constant rate of −1.2 nm/GPa up to a threshold pressure of ∌ 9.4 GPa. We demonstrate recovery of the original nanoparticles upon decompression of the irradiated matrix. The mechanisms for reversible nanocolloid-size variation are analyzed with first-principles simulations. We show that a pressure-driven increase in the binding energy between fluorine centers is responsible for the observed nanoparticle shrinkage. We argue that the same method can be used to generate other metallic colloids (Li, K, Sr, and Cs) with tailored dimensions by simply selecting an appropriate matrix

    Throughflow Velocity Crossing the Dome of Erupting Bubbles in 2-D Fluidized Beds

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    A new non-intrusive method for measuring the throughflow velocity crossing the dome of erupting bubbles in freely bubbling 2-D fluidized beds is presented. Using a high speed video-camera, the dome acceleration, drag force and throughflow velocity profiles are obtained for different experiments, varying the superficial gas velocity. The acceleration profiles show greater values in the dome zone where the gravity component is negligible. The drag force and the throughflow velocity profiles show a uniform value in the central region of the dome (40 deg \u3c \u3c 140 deg) and the total throughflow increases with the superficial gas velocity

    Hydrodynamic Characteristics of a Fluidized Bed with Rotating Distributor

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    The performance of a novel rotating distributor fluidized bed is presented. The pressure drop and the standard deviation of pressure fluctuations, σp, were used to find the minimum fluidization velocity, Umf, and to characterize the quality of fluidization at different rotational speeds of the distributor plate. Experiments were conducted in the freely bubbling regime in a 0.19 m i.d. fluidized bed, operating with Group B particles according to Geldart’s classification. A decrease in Umf is observed when the rotational speed increases. Frequency analysis of pressure fluctuations shows that fluidization can be controlled by the adjustable rotational speed, at several excess gas velocities

    Dietary level of fibre and age at weaning affect the proliferation of Clostridium perfrigens in the caecum, the incidence of Epizootic Rabbit Enteropathy and the performance of fattening rabbits

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    An experiment was conducted to investigate the effects of dietary fibre content and weaning age on Clostridium perfringens proliferation in the caecum and fattening mortality in growing rabbits farmed in a facility having Epizootic Rabbit Enteropathy. The experiment consisted in a 2 × 2 factorial arrangement with two weaning ages (28 days vs. 42 days) and two levels of dietary neutral detergent fibre assayed with a heat stable amylase and expressed exclusive of residual ash (aNDFom; 330 g/kg vs. 425 g/kg). Controls were made during two consecutive experimental periods that differed in hygienic environmental conditions by modifying the intensity of cleaning and disinfection in the farm previous to the trial. An interaction (P<0.001) was detected among the independent variables studied on Cl. perfringens enumeration in the caecal contents, as minimal values for this trait were obtained in non-medicated animals reared in a clean environment, and especially when they were weaned at a later age and fed the diet with the lower fibre content. The treatments studied also led to a variation in fattening mortality (from 4.7% to 34.0%), which was highly and positively correlated (P<0.001) to the average Cl. perfringens caecal counts in each combination of treatments. The results of the current study indicate that high counts of Cl. perfringens in the caecum can be used as an indicator of Epizootic Rabbit Enteropathy, and suggest that strategies designed to control its proliferation in the caecum might help to limit fattening mortality in rabbit fed diets not-medicated with antibiotics

    Structural anatomical investigation of long-term memory deficit in behavioural frontotemporal dementia

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    Although a growing body of work has shown that behavioral variant frontotemporal dementia (bvFTD) could present with severe amnesia in approximately half of cases, memory assessment is currently the clinical standard to distinguish bvFTD from Alzheimer's disease (AD). Thus, the concept of "relatively preserved episodic memory" in bvFTD remains the basis of its clinical distinction from AD and a criterion for bvFTD's diagnosis. This view is supported by the idea that bvFTD is not characterized by genuine amnesia and hippocampal degeneration, by contrast to AD. In this multicenter study, we aimed to investigate the neural correlates of memory performance in bvFTD as assessed by the Free and Cued Selective Reminding Test (FCSRT). Imaging explorations followed a two-step procedure, first relying on a visual rating of atrophy of 35 bvFTD and 34ADpatients' MRI, contrasted with 29 controls; and then using voxel-based morphometry (VBM) in a subset of bvFTD patients. Results showed that 43% of bvFTD patients presented with a genuine amnesia. Data-driven analysis on visual rating data showed that, in bvFTD, memory recall & storage performances were significantly predicted by atrophy in rostral prefrontal and hippocampal/perihippocampal regions, similar to mild AD. VBM results in bvFTD (p(FWE)<0.05) showed similar prefrontal and hippocampal regions in addition to striatal and lateral temporal involvement. Our findingsDistALZ CONICET CONICYT/FONDECYT 1170010 1160940 FONCyT, PICT 2012-0412 2012-1309 CONICYT/FONDAP 15150012 INECO Foundatio

    Taquipnea transitoria del recién nacido en el Hospital General Docente "Ciro Redondo García". Artemisa 2009

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    Entre 40-50 % de los casos con síndrome de dificultad respiratoria (SDR)evolucionan como una Taquipnea Transitoria (TTRN). Se realizó un estudioretrospectivo descriptivo, con el objetivo de conocer el comportamiento de la(TTRN) en la Unidad de Cuidados Especiales de Neonatología (UCEN) del HospitalGeneral Docente "Ciro Redondo García", en el período comprendido enero 2008hasta diciembre 2009. El universo fue 113 recién nacidos (RN) con SDR y 72constituyeron la muestra con diagnóstico de (TTRN) por un muestreo noprobabilístico. Se confeccionó un formulario y se recogieron variables relacionadascon el parto y examen físico del RN. Los datos se procesaron estadísticamente porel sistema Excel. Aproximadamente 3 de cada 4 RN con (TT) nacen por cesårea, atérmino, del sexo masculino, normopesos, conteo de apgar normal y tiempo deevolución inferior a 120 horas. Se concluye que el comportamiento de la TTRN ennuestro servicio resultó elevado.Palabras clave: Síndrome de dificultad respiratoria (SDR), recién nacidos (RN),Taquipnea Transitoria del recién nacido (TTRN)

    Los gasterĂłpodos terrestres del Cuaternario Superior de Gran Canaria (Islas Canarias)- Land gastropods of the Upper Quaternary in Gran Canaria (Canary Islands)

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    Hemos estudiado la estratigrafía, cronología y paleontología de ocho depósitos sedimentarios (siete paleodunas y un derrubio de ladera) del Pleistoceno Superior de la isla de Gran Canaria (Islas Canarias). Las paleodunas se caracterizan por una alternancia de dunas y paleosuelos, que varía entre un ciclo en la Playa de Jinåmar, y once en el Lazareto (Gando). La cronología de estos depósitos, obtenida por racemización de aminoåcidos sobre ejemplares del género Theba y calibrada con 14C, muestra una edad entre 44,4 Ka a 22,2 Ka. La aminoestratigrafía ha permitido asignar estos depósitos a cuatro aminozonas (AM2 a AM5) de las registradas por Ortiz et al. (2006). Las asociaciones fósiles de gasterópodos terrestres estån representadas por 20 especies pertenecientes a 8 familias, con un grado de endemismo del 95%. Los cambios faunísticos detectados, con respecto a la actualidad, se refieren a la extinción del 25 % de las especies del Pleistoceno Superior, y a la disminución de la extensión geogråfica de algunas especies como Theba arinagae y T. aff. grasseti. - A stratigraphic, chronological and paleontological study of eight sedimentary deposits (seven palaeodunes and a colluvial slide) in the Upper Pleistocene of Gran Canaria (Canary Islands) has been undertaken. The palaeodunes are characterized by dune-palaeosoil alternation, from an only cycle in Playa de Jinåmar to eleven in Lazareto (Gando). The chronology of these deposits, obtained by amino acid racemisation and 14C datations in Theba genus samples, displays an age between 44,4 Ka and 22,2 Ka. The aminostratigraphy study appoints to these sediments belong to four amino zones (AM2 to AM5) reported by Ortiz et al. (2006). The land snail fossil assemblages are represented by 20 species belonging to eight families, with an endemic degree around 95%. The detected fossil fauna changes with regard to present fauna reveal an Upper Pleistocene species extinction at about 25% and geographic extension decreasing of some species as Theba arinagae and T. aff. grasset

    Development of simplified sampling methods for behavioural data in rabbit does

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    [EN] The aim of this study was to compare the results of different simplified sampling methods for behavioural data compared to reference records of 24-h in order to assess rabbit doe behaviours at different physiological stages (gestation and lactation) in animals housed in 2 types of cages (conventional and alternative). In total, we analysed 576 h of continuous video of 12 rabbit does at the end of lactation and the same females after weaning. The behavioural observations were studied using 3 independent categories of classification (location in the cage, posture and functional behaviours). Continuous behavioural recordings of 24 h were considered as the reference method to validate another 4 data collection sampling methods by aggregated video recordings of different frequency and duration [regular short and long methods with 2.4 and 8 h of observation respectively, and irregular (more frequent during the active period) short and long methods with 6 and 8 h of observation, respectively]. The current results showed that, independently of the housing system, the best method to reduce the total observation time required to assess rabbit does’ behaviour depends on the trait studied and physiological stage of the does. In gestating does, irregular methods were not suitable to estimate behaviours of long duration such as lying, sitting, resting and grooming. However, in both physiological stages, regular methods were accurate for location behaviours, postures and functional behaviours of long duration. Instead, for the study of infrequent behaviours performed mainly during dark period, where coefficients of variation were high, the irregular long method led to the lowest mean estimation errors.Alfonso-Carrillo, C.; MartĂ­n, E.; Blas, CD.; Ibåñez, M.; GarcĂ­a-Ruiz, A.; GarcĂ­a-Rebollar, P. (2017). Development of simplified sampling methods for behavioural data in rabbit does. World Rabbit Science. 25(1):87-94. doi:10.4995/wrs.2017.3627SWORD879425

    Relationship among research collaboration, number of documents and number of citations. A case study in Spanish computer science production in 2000-2009.

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    This paper analyzes the relationship among research collaboration, number of documents and number of citations of computer science research activity. It analyzes the number of documents and citations and how they vary by number of authors. They are also analyzed (according to author set cardinality) under different circumstances, that is, when documents are written in different types of collaboration, when documents are published in different document types, when documents are published in different computer science subdisciplines, and, finally, when documents are published by journals with different impact factor quartiles. To investigate the above relationships, this paper analyzes the publications listed in the Web of Science and produced by active Spanish university professors between 2000 and 2009, working in the computer science field. Analyzing all documents, we show that the highest percentage of documents are published by three authors, whereas single-authored documents account for the lowest percentage. By number of citations, there is no positive association between the author cardinality and citation impact. Statistical tests show that documents written by two authors receive more citations per document and year than documents published by more authors. In contrast, results do not show statistically significant differences between documents published by two authors and one author. The research findings suggest that international collaboration results on average in publications with higher citation rates than national and institutional collaborations. We also find differences regarding citation rates between journals and conferences, across different computer science subdisciplines and journal quartiles as expected. Finally, our impression is that the collaborative level (number of authors per document) will increase in the coming years, and documents published by three or four authors will be the trend in computer science literature
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