1,669 research outputs found

    Estudio a corto plazo en artroplastia total de cadera no cementada con par de fricción cerámica-cerámica

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    Se revisan 38 prótesis con par de fricción cerámica-cerámica en 31 pacientes intervenidos durante los años 2000 a 2003. La edad media era de 47,3 años. La valoración clínica con la escala de Harris pasó de 53 puntos de media en el preoperatorio a 97 en el postoperatorio lo que permitió establecer un 76,3% de resultados excelentes y un 23,7 de buenos. No hemos podido constatar ninguna complicación asociada al par cerámica-cerámica. Los resultados iniciales con el par cerámica-cerámica son superponibles a otras pares de fricción, su utilización en implantes que han demostrado su eficacia con otros pares de fricción, la mejoría en la fabricación y la estricta observación de la técnica quirúrgica permite obviar el riesgo de fractura. Merced a su baja incidencia de desgaste y buen comportamiento biológico representa una alternativa real para su implantación en pacientes jóvenes o con una actividad elevada.From 2000 to 2003, 38 patients underwent ceramic on ceramic bearing total hip artrhoplasty. Mean age was 47.3 years. Clinical evaluation with the harris hip score increased from 53 points preoperatively to 97 postoperatively. There were no complications associated with ceramic on ceramic bearing.Initial results are similar to those found with others bearing surfaces. The use of ceramics in implants that have shown their effectiviness with others bearing surfaces, improvement in manufactured of the ceramics and a carefull surgery decreased the risk os fracture. Low incidence of wear debris and biological caracteristics makes ceramics a real alternative in young or high activity patients

    Detection and mapping of burnt areas from time series of MODIS-derived NDVI data in a Mediterranean region

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    Moderate resolution remote sensing data, as provided by MODIS, can be used to detect and map active or past wildfires from daily records of suitable combinations of reflectance bands. The objective of the present work was to develop and test simple algorithms and variations for automatic or semiautomatic detection of burnt areas from time series data of MODIS biweekly vegetation indices for a Mediterranean region. MODIS-derived NDVI 250m time series data for the Valencia region, East Spain, were subjected to a two-step process for the detection of candidate burnt areas, and the results compared with available fire event records from the Valencia Regional Government. For each pixel and date in the data series, a model was fitted to both the previous and posterior time series data. Combining drops between two consecutive points and 1-year average drops, we used discrepancies or jumps between the pre and post models to identify seed pixels, and then delimitated fire scars for each potential wildfire using an extension algorithm from the seed pixels. The resulting maps of the detected burnt areas showed a very good agreement with the perimeters registered in the database of fire records used as reference. Overall accuracies and indices of agreement were very high, and omission and commission errors were similar or lower than in previous studies that used automatic or semiautomatic fire scar detection based on remote sensing. This supports the effectiveness of the method for detecting and mapping burnt areas in the Mediterranean region.This work was supported by the research projects FEEDBACK (CGL2011-30515- C02-01), funded by the Spanish Ministry of Innovation and Science, CASCADE (GA283068), funded by European Commission under the Seventh Framework Program, and GVPRE/2008/310, funded by the Valencia Regional Government (Generalitat Valenciana)

    Studies for the application of an adaptative controller to hydroturbine generators

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    This paper describes some studies made towards the automatization of hydroturbine generators with microcomputers. The overall design will include an automata controlling the starting-up and shutting-down procedure as well as an self-tuning regulator for the speed control. A self-tuning regulator based on the classical pole-assignment-method is studied. The algorithm uses a fast procedure for solving the polynomial equation implicit to selfturner regulator. This procedure is very simple from a computational point of view as only applications of elementary transformations on a 2 x 2 polynomial matrix are needed.The algorithm has been programmed on a Digital PDP 1103 computer and applied to some test problems

    The glutamine synthetase gene family in Populus

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    <p>Abstract</p> <p>Background</p> <p>Glutamine synthetase (GS; EC: 6.3.1.2, L-glutamate: ammonia ligase ADP-forming) is a key enzyme in ammonium assimilation and metabolism of higher plants. The current work was undertaken to develop a more comprehensive understanding of molecular and biochemical features of <it>GS </it>gene family in poplar, and to characterize the developmental regulation of <it>GS </it>expression in various tissues and at various times during the poplar perennial growth.</p> <p>Results</p> <p>The <it>GS </it>gene family consists of 8 different genes exhibiting all structural and regulatory elements consistent with their roles as functional genes. Our results indicate that the family members are organized in 4 groups of duplicated genes, 3 of which code for cytosolic GS isoforms (GS1) and 1 which codes for the choroplastic GS isoform (GS2). Our analysis shows that <it>Populus trichocarpa </it>is the first plant species in which it was observed the complete <it>GS </it>family duplicated. Detailed expression analyses have revealed specific spatial and seasonal patterns of <it>GS </it>expression in poplar. These data provide insights into the metabolic function of GS isoforms in poplar and pave the way for future functional studies.</p> <p>Conclusions</p> <p>Our data suggest that <it>GS </it>duplicates could have been retained in order to increase the amount of enzyme in a particular cell type. This possibility could contribute to the homeostasis of nitrogen metabolism in functions associated to changes in glutamine-derived metabolic products. The presence of duplicated <it>GS </it>genes in poplar could also contribute to diversification of the enzymatic properties for a particular GS isoform through the assembly of GS polypeptides into homo oligomeric and/or hetero oligomeric holoenzymes in specific cell types.</p

    Preparation and characterization of 33-S samples for 33-S(n,alpha)30-Si cross-section measurements at the n_TOF facility at CERN

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    Thin 33S samples for the study of the 33S(n,a)30Si cross-section at the n_TOF facility at CERN were made by thermal evaporation of 33S powder onto a dedicated substrate made of kapton covered with thin layers of copper, chromium and titanium. This method has provided for the first time bare sulfur samples a few centimeters in diameter. The samples have shown an excellent adherence with no mass loss after few years and no sublimation in vacuum at room temperature. The determination of the mass thickness of 33S has been performed by means of Rutherford backscattering spectrometry. The samples have been successfully tested under neutron irradiation.Ministerio de Economía y Competitividad de España-FPA2013-47327- C2-1-R, FPA2014-53290-C2-2-P, FPA2016-77689-C2-1-RJunta de Andalucía-P11-FQM-8229Ministerio de Economía y Empresa de España (Fondos FEDER)-FIS2015-69941-C2-1-PAECC (Asociación Española Contra el Cáncer)-PS16163811POR

    Resultados en recambios de cotilo mediante la técnica de Sloof: nuestra experiencia

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    Objetivos: osteolisis es un importante problema para el cirujano en los recambios de cotilo. Hoy en día existen múltiples técnicas para intentar subsanar este defecto. Una de ellas es la Técnica de Sloof. Hemos querido mostrar nuestros resultados con esta técnica. Material y métodos: Se revisaron 20 pacientes entre 1999 y octubre 2003 clasificados con la escala de Paprosky intervenidos con esta técnica. Se valoraron resultados en cuanto a mejoría del dolor, funcionalidad, actividad y consolidación radiológica, usando para ello las escalas de Harris. Resultados: La mayoría de los pacientes obtuvieron una mejoría significativa del dolor y una función suficiente como para realizar su vida de forma independiente, consiguiéndose la incorporación del injerto en todos los casos.Aim: The osteolysis of the pelvis is an important problem for the surgeon associated with acetabular revision. Nowadays there are many techniques which try to solve such a defect. One of them is the Sloof’s technique. We have shown our results using this technique. Materials and Methods: Study of 20 patients from 1999 to October 2003 who were treated with this technique. Results related to pain-free, functionality, activity and radiology consolidation, have been valued using Harris scale. Results: Most of patients got a significant pain diminution and a function enough to achieve their lives in a self- sufficiency way. We have obtained the graft incorporation in all the cases

    Histogenesis and cell differentiation in the retina of Thunnus thynnus: a morphological and immunohistochemical study

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    This study examines the anatomical development of the visual system of Atlantic bluefin tuna, Thunnus thynnus, during the first 15 days of life at histological level, with emphasis in the immunohistochemical characterization of different cell types. As an altricial fish species, the retina was not developed at hatching. The appearance of eye pigmentation and the transformation of the retina from an undifferentiated neuroblastic layer into a laminated structure occurred during the first two days of life. At 16 days after hatching (DAH), the ganglion cells were arranged in a single row in the central region of the retina and the outer segments of the photoreceptors were morphologically developed. Furthermore, at this age, all the retinal cell types were immunohistochemically characterized. The presence of ganglion cell axons was confirmed with the TUJ1 antibody and the existence of functional synapses in the plexiform layers with antibodies against SV2. Cone opsins were immunostained with antibodies against visinin and CERN-922 immunoreactive rods were also identified. Different subpopulations of amacrine cells were immunostained with antibodies against αTH and PV. Highly GS-immunoreactive Müller cells were also detected at this age. These observations suggested that the T. thynnus retina was fully functional at the end of the second week of life. Basic studies on early morphology of the visual system and larval behaviour are necessary to support applied research on larval rearing. Furthermore, they may have implications for understanding larval ecology in the wild.Versión del edito

    Sanitation network sulfide modeling as a tool for asset management. The case of the city of Murcia (Spain)

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    Hydrogen sulfide (H2S) generated in sewer networks induces corrosion which today constitutes the main cause of deterioration of concrete pipes. Information regarding the H2S concentration inside sewer networks, as well as its control and reduction, has become one of the most important concerns in sanitation systems management nowadays. Modeling sulfide dynamics is the key to understanding corrosion processes. A dynamic model (called EMU-SANETSUL) was developed to calculate the H2S concentration in both the water and the gas phases of the main sewers of the city of Murcia (Spain). The model was calibrated with data from field measurements taken from both the gas phase and wastewater. Samples were taken in the network from 2016 to 2019. The model achieved an accuracy index and error index in the ranges of 57% and 15%, respectively. Empirical equations of reaction are used, and calibration parameters are detailed. The code uses an explicit discretization technique, named the Discrete Volume Element Method (DVEM). A map with the annual average concentration of H2S at the gas phase inside each pipe of the simulated network is presented. Values are compared with the mechanical deterioration inventory from closed-circuit television (CCTV) inspections performed by the Municipal Sanitation Company of the city of Murcia (EMUASA). Mechanical deterioration of pipes has diverse causes, including corrosion of pipes by H2S. Sections with high H2S concentrations that match with mechanical wear can be considered susceptible to being prioritized when rehabilitation works are being planned. Therefore, H2S concentration modeling provides valuable information for asset management of the sewer network.This research was funded by the Municipal Sanitation Company of the city of Murcia (EMUASA), grant numbers 4904/17IC-C and 5397/18IC-C from 2016 to 2019 for the Study of preventive and corrective measures to be applied in the sewerage network to minimize corrosion in the concrete pipes of the sewerage network of the city of Murcia by the action of hydrogen sulfide

    A fast model to resolve the velocity-space of fast-ion losses detected in ASDEX Upgrade and MAST Upgrade

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    A forward model to resolve the fast-ion loss velocity-space on a fast-ion loss detector (FILD) probe head (FILDSIM) has been extended, making it possible to perform real-time analysis of the FILD data ("real-time FILDSIM"). Parametric pre-processing with FILDSIM enables real-time mapping of the raw FILD measurements to the velocity-space of the fast-ion distribution reaching the FILD probe, which depends on the local magnetic field at the probe head. Such parametric pre-processing facilitates the study of fast-ion losses in stages of the discharge other than the flat-top, such as the ramp-up phase when changes in the local magnetic field at the probe head cannot be neglected. Real-time FILDSIM has been applied to the existing and newly installed FILDs in ASDEX Upgrade and will be used for the forthcoming FILD in MAST-Upgrade. Due to the larger size of the MAST-U FILD probe, the approximation used in FILDSIM of a uniform magnetic field in the FILD region has been generalised to the case of a non-uniform field, with gyro-orbits calculated numerically in this field.Universidad de Sevilla PP2016-7145Comunidad Europea de Energía Atómica (EURATOM) 633305
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