2,107 research outputs found

    Estudio comparativo de equipos fijos de pedestal y su aplicaci贸n en la detecci贸n del tr谩fico incontrolado de material radiactivo en aeropuertos

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    En este trabajo se analiza la respuesta de tres equipos comerciales, dise帽ados para detectar el tr谩fico il铆cito o el desplazamiento involuntario de material radiactivo en aeropuertos cuando es transportado por los pasajeros. Se han comparado tres instrumentos fijos de pedestal: el equipo APM de Bicron, el equipo GR-606 de Exploranium y el equipo FHT-1372 de Thermo Eberline. En esta evaluaci贸n inicial, realizada en el Laboratorio de Ingenier铆a Nuclear de la Escuela de Caminos, Canales y Puertos, se observ贸 que el equipo FHT-1372 present贸 una respuesta de detecci贸n m谩s r谩pida, sensible y permiti贸 la medida de tasa de dosis total y tasa de dosis artificial. Este equipo fue instalado en la salida de la aduana de pasajeros del aeropuerto internacional de Barajas durante un periodo operativo de 108 d铆as en el a帽o 2002 y pasaron un total de 1.339.931 personas. Este periodo se dividi贸 en 5 sesiones para poder establecer los niveles de investigaci贸n adecuados para detectar una posible incidencia de material radiactivo, que finalmente se fijaron en 110 nSv/h para la tasa de dosis total y 25 nSv/h para la tasa de dosis artificial. Durante dicho periodo se detectaron 39 posibles incidencias por encima del l铆mite de investigaci贸n establecido para las diferentes sesiones, 5 de ellas con un valor 10 veces superior al fondo ambiental de la sala donde se instal贸 el equipo (alrededor de 90 nSv/h) y ninguna super贸 el nivel de 100 渭Sv/h a 1 m de distancia que la Organizaci贸n Internacional de la Energ铆a At贸mica (OIEA) establece como l铆mite para el transporte l铆cito de material radiactivo

    Lack of association of a variable number of aspartic acid residues in the asporin gene with osteoarthritis susceptibility: case-control studies in Spanish Caucasians

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    A recent genetic association study has identified a microsatellite in the coding sequence of the asporin gene as a susceptibility factor for osteoarthritis (OA). Alleles of this microsatellite determine the variable number of aspartic acid residues in the amino-terminal end of the asporin protein. Asporin binds directly to the growth factor transforming growth factor beta and inhibits its anabolic effects in cartilage, which include stimulation of collagen and aggrecan synthesis. The OA-associated allele, with 14 aspartic acid residues, inhibits the anabolic effects of transforming growth factor beta more strongly than other asporin alleles, leading to increased OA liability. We have explored whether the association found in several cohorts of Japanese hip OA and knee OA patients was also present in Spanish Caucasians. We studied patients that had undergone total joint replacement for primary OA in the hip (n = 303) or the knee (n = 188) and patients with hand OA (n = 233), and we compared their results with controls (n = 294) lacking overt OA clinical symptoms. No significant differences were observed in any of the multiple comparisons performed, which included global tests of allele frequency distributions and specific comparisons as well as stratification by affected joint and by sex. Our results, together with reports from the United Kingdom and Greece, indicate that the stretch of aspartic acid residues in asporin is not an important factor in OA susceptibility among European Caucasians. It remains possible that lifestyle, environmental or genetic differences allow for an important effect of asporin variants in other ethnic groups as has been reported in the Japanese, but this should be supported by additional studies

    M茅todo experimental para identificar el nivel de atenci贸n en las personas

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    The student鈥檚 level of attention in the school environment is related to different physiological variables of the body. The study of physiological signals related to attention such as brain waves, heart rate, breathing rate, sweat, sight tracking, among others, has revealed significant advances in recent times. This work presents the development of a system to measure the level of attention in real-time and quantitatively. The sensed variables to determine the user鈥檚 level of attention are Beta-type brain waves and two angles that describe the student鈥檚 corporal posture. The mathematical analysis describes the process to obtain the correlation between the percentages of the brain waves with the angles from the corporal posture. The resultant coefficient of correlation is in a considerable correlation interval. It denotes that the corporal posture can be considered a parameter that influences students鈥 level of attention.El nivel de atenci贸n de un estudiante en su entorno escolar est谩 relacionado con diferentes variables fisiol贸gicas del cuerpo humano. El estudio de las se帽ales fisiol贸gicas relacionadas con el nivel de atenci贸n como ondas cerebrales, frecuencia card铆aca, entre otros, ha revelado grandes avances en los 煤ltimos tiempos. En este trabajo se presenta el desarrollo de un sistema para medir la atenci贸n en tiempo real y de forma cuantitativa. Las variables sensadas para poder determinar el nivel de atenci贸n del usuario son: Las ondas cerebrales tipo beta y dos 谩ngulos que describen la postura corporal del estudiante. Se busca la correlaci贸n el porcentaje de atenci贸n que se obtiene de las ondas cerebrales, con los 谩ngulos obtenidos de la postura corporal a trav茅s de un an谩lisis matem谩tico. El coeficiente de correlaci贸n resultante denota que la postura corporal puede considerarse como un par谩metro que influye en el nivel de atenci贸n de los estudiantes

    Fragmentaci贸n primaria en la combusti贸n en lecho fluidizado de pellets de serr铆n

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    Parece ser que La combusti贸n en lecho fluidizado tiene buenas perspectivas dentro de las opciones tecnol贸gicas para la generaci贸n de energ铆a a partir de un combustible, dada su flexibilidad respecto a los combustibles a emplear como sus posibilidades de operaci贸n limpia y eficiente, junto a la posibilidad de cambio de escala. En este art铆culo se exponen los resultados alcanzados a escala de planta piloto en el funcionamiento de un reactor de lecho fluidizado en la combusti贸n de pellets de serr铆n con vistas a su aplicaci贸n en el aprovechamiento de los residuos s贸lidos en el proceso de producci贸n de bioetanol de lignocelul贸sicos

    Cis-regulation of IRF5 expression is unable to fully account for systemic lupus erythematosus association: analysis of multiple experiments with lymphoblastoid cell lines

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    INTRODUCTION: Interferon regulatory factor 5 gene (IRF5) polymorphisms are strongly associated with several diseases, including systemic lupus erythematosus (SLE). The association includes risk and protective components. They could be due to combinations of functional polymorphisms and related to cis-regulation of IRF5 expression, but their mechanisms are still uncertain. We hypothesised that thorough testing of the relationships between IRF5 polymorphisms, expression data from multiple experiments and SLE-associated haplotypes might provide useful new information. METHODS: Expression data from four published microarray hybridisation experiments with lymphoblastoid cell lines (57 to 181 cell lines) were retrieved. Genotypes of 109 IRF5 polymorphisms, including four known functional polymorphisms, were considered. The best linear regression models accounting for the IRF5 expression data were selected by using a forward entry procedure. SLE-associated IRF5 haplotypes were correlated with the expression data and with the best cis-regulatory models. RESULTS: A large fraction of variability in IRF5 expression was accounted for by linear regression models with IRF5 polymorphisms, but at a different level in each expression data set. Also, the best models from each expression data set were different, although there was overlap between them. The SNP introducing an early polyadenylation signal, rs10954213, was included in the best models for two of the expression data sets and in good models for the other two data sets. The SLE risk haplotype was associated with high IRF5 expression in the four expression data sets. However, there was also a trend towards high IRF5 expression with some protective and neutral haplotypes, and the protective haplotypes were not associated with IRF5 expression. As a consequence, correlation between the cis-regulatory best models and SLE-associated haplotypes, regarding either the risk or protective component, was poor. CONCLUSIONS: Our analysis indicates that although the SLE risk haplotype of IRF5 is associated with high expression of the gene, cis-regulation of IRF5 expression is not enough to fully account for IRF5 association with SLE susceptibility, which indicates the need to identify additional functional changes in this gene

    Polymeric pigments formed in sequential fermentation of red fresh musts by adding flavan-3-ols

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    Red wine pigments are susceptible to degradation by light, SO2 and changes in pH and temperature1,2. The formation of pyranoanthocyanins and polymeric pigments during fermentation and wine aging promote the stability of such pigments3. Glycolytic metabolites (e.g. acetaldehyde and pyruvic acid) may interact with anthocyanins and flavan-3-ols to form more stable molecules4 without a drastic change in hue values. Procyanidins are molecules from the flavanoids family that may condense with anthocyanins5. The contribution of non-Saccharomyces yeasts (e.g. L. thermotolerans, M. pulcherrima and T. delbrueckii), in sequential fermentation with S. cerevisiae and S. pombe, to the production of stable pigments was assessed in this project. with the use of HPLC-DAD/MS-ESI. The red musts have been enriched with flavanols prior fermentation. Fermentative volatiles and sensorial analysis were also performed to characterize experimental wines produced

    Heterogeneous Photocatalytic Degradation of Ibuprofen Over TiO2鈥揂g Supported on Activated Carbon from Waste Tire Rubber

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    In recent years it has been discovered that some common use medicines, such as ibuprofen and other nonsteroidal anti-inflammatory drugs, are found in water sources in concentrations that have the potential to affect aquatic organisms. On the other hand, waste used tires are a massive problem for the environment due to the leaching of toxic compounds to soils and water. Also, the exposition to environmental conditions can make them sources of vectors like mosquitoes. In this work, three activated carbon (AC) catalysts derived from waste tire rubber, titanium dioxide and silver were synthesized using the sol鈥揼el method. Morphological characterizations such as SEM and TEM were performed in which, the agglomeration of titanium particles and silver crystals on the surface of the AC is evident. In the XRD analysis, the presence of elemental silver nanoparticles was detected. In the diffuse reflectance spectroscopy analysis, the decrease in the titanium band gap, as well as activity in the visible spectrum, was observed. The photocatalytic tests were performed at pH 3 and 7 in the presence of UV/Vis radiation. These tests show that there are differences between the catalyst in both, UV and visible regions. Adsorption is a major phenomenon for the removal of ibuprofen, followed by photolytic decomposition. In visible spectra, the catalysts show a good performance for the removal of ibuprofen

    Effect of Steel Fibre Reinforcement on Flexural Fatigue Behaviour of Notched Structural Concrete

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    ABSTARCT: One of the biggest challenges in facilitating the installation of concrete is the development of fibre-reinforced concrete. Although nowadays fibre reinforced concrete is relatively common, it is still necessary to deepen in the study on its behaviour, especially regarding its fatigue behaviour. This paper proposes a new methodology to analyse the bending fatigue behaviour of notched test specimens. From these tests, it was possible to verify that, despite carrying out the tests with load control, the presence of fibres extends the fatigue life of the concrete after cracking. This effect is of great importance since during the extra lifetime with the cracked concrete, the damage to the concrete will be evident and the corresponding maintenance measures can be carried out. Regarding the analysis of the results, in addition to obtaining a traditional S-N curve, two new criteria have been applied, namely energy and notch growth. From these two new approaches, it was possible to determine critical energy values that can be used as predictive indicators of the collapse of the element. Moreover, from the notch growth analysis, it was possible to determine crack growth rate as a function of the stress conditions for the concrete and the specific geometry. From the comparison among the results obtained from the different tests, a limit cracking index of 0.05 mm can be defined

    Efeitos da disrup莽茫o end贸crina na gesta莽茫o: uma revis茫o sistem谩tica

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    Endocrine disruptors are ubiquitous natural and synthetic environmental pollutants that can mimic, block or disturb normal hormonal function. Environmental exposure to these pollutants is almost impossible to prevent due to their presence in the air, water, soil, food and in many other materials with which we come in contact daily, such as plastics. Foetuses are vulnerable during pregnancy because their organism is in a developmental stage, and any disruption may affect their health in the short and/or long term. There is some evidence that these substances disrupt tissue differentiation and growth processes, cause birth defects and affect the length of pregnancy. In this review we will focus on environmental epidemiology and related literature in order to update current knowledge based on the actual evidence of the effects of these substances on the aetiology of preterm delivery, miscarriages, low birth weight, malformations, cryptorchidism, hypospadias and micropenis. The difficulty in studying this topic is due to the high number of involved factors, which makes the available results inconclusive or even contradictory. Consequently, further research is necessary.Los alteradores endocrinos son contaminantes ambientales, naturales y sint茅ticos, ubicuos, que pueden mimetizar, bloquear o alterar funciones hormonales. La exposici贸n ambiental a estos contaminantes es pr谩cticamente imposible de evitar debido a que est谩n presentes en el aire, en el agua, en los suelos, en los alimentos, y en muchos de los materiales con los que estamos en contacto diariamente, como los pl谩sticos. La gestaci贸n supone una etapa de vulnerabilidad para el feto porque su organismo est谩 en proceso de desarrollo y cualquier alteraci贸n puede afectar su salud a corto o largo plazo. Hay cierta evidencia de que estas sustancias alteran procesos de crecimiento y diferenciaci贸n de tejidos, producen malformaciones y afectan la duraci贸n del embarazo. Hasta el momento se conoce algo de sus efectos en la etiolog铆a de la criptorquidia, hipospadias y micropene, abortos espont谩neos, partos prematuros y el bajo peso al nacimiento, efectos que ser谩n revisados en este documento que quiere aportar una actualizaci贸n del conocimiento, concentr谩ndose en la epidemiolog铆a ambiental y la literatura relacionada. La dificultad para estudiar este tema por la cantidad de factores que intervienen hace que los resultados existentes no sean concluyentes o incluso contradictorios, por lo que es necesario que se siga investigando.Os disruptores end贸crinos s茫o contaminantes ambientais ub铆quos, naturais e sint茅ticos, que podem mimetizar, bloquear ou alterar fun莽玫es hormonais. A exposi莽茫o ambiental a estes contaminantes 茅 quase imposs铆vel de evitar porque est茫o presentes no ar, na 谩gua, no solo, nos alimentos e em muitos materiais de uso cotidiano como os pl谩sticos. A gesta莽茫o 茅 uma etapa de vulnerabilidade para o feto porque o organismo est谩 em processo de desenvolvimento e qualquer altera莽茫o pode afetar gravemente a sua sa煤de a curto ou longo prazo. Existe alguma evid锚ncia de que estas sust芒ncias alteram processos de crescimento e diferencia莽茫o de tecidos, produzem malforma莽玫es e afetam a dura莽茫o da gravidez. Neste momento j谩 existe algum conhecimento sobre os seus efeitos na etiologia da criptorquidia, hipospadia, microp茅nis, aborto espont芒neo, parto prematuro e baixo peso 脿 nascen莽a. Efeitos esses que ser茫o revisados neste documento visando uma atualiza莽茫o do conhecimento, concentrando-se na epidemiologia ambiental e na literatura relacionada. A dificuldade para estudar este tema pela quantidade de fatores intervenientes faz com que os resultados existentes n茫o sejam conclusivos ou at茅 que sejam contradit贸rios, pelo que, ser谩 necess谩rio que se continue investigando
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