90 research outputs found

    Análisis de los criterios de construcción y diseño para minimizar el riesgo de figuración de particiones interiores por excesiva deformabilidad de la estructura horizontal

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    La Cátedra de Edificación de la Universidad Politécnica de Madrid, en colaboración con el instituto Técnico de Materiales y Construcciones (iNTEMAC), está llevando a cabo una investigación sobre las distintas variables que pueden influir en ia aparición de fisuras en tabiques y cerramientos de edificios con estructura de hormigón armado debido a la flecha vertical de la estructura horizontal, problema que aún no ha sido resuelto de forma totalmente satisfactoria con los criterios de las normativas, en particular las vigentes en España. De un primer análisis de de los casos analizados se deduce la importante influencia de otras variables no contempladas por la normativa en la aparición de daños y en la intensidad de estos. En la presente comunicación se exponen los principales resultados obtenidos en dichos análisi

    Características de la práctica físico-deportiva en estudiantes universitarios

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    Dada la creciente preocupación por la adopción y el mantenimiento de un estilo de vida saludable, asociado a los importantes beneficios fisiológicos y psicológicos que conlleva la práctica de ejercicio físico y, al escaso interés que este hecho despierta entre la población adulta, una vez que se ha abandonado la etapa educativa, hemos considerado oportuno realizar un análisis de la situación de los estudiantes universitarios, a través de la descripción de los aspectos sociodemográficos que configuran los perfiles del alumnado. Centrándonos en estas edades porque, tal y como mencionan Blasco y cols. (1996), es a partir de la edad de 17-18 años, cuando parece que los altibajos de adherencia se hacen más evidentes, con lo que la experiencia deportiva en la Universidad se convierte en un buen predictor del nivel de dedicación en la edad adulta. Para cumplir tal objetivo hemos desarrollado el Cuestionario de Motivaciones e Intereses hacia las Actividades Físico-Deportivas (M.I.A.F.D.), aplicado a una muestra de 1512 estudiantes (38,4% hombres y 61,6% mujeres). Así, del total de alumnos entrevistados, el 52,7% practica alguna actividad físico-deportiva, de los cuales sólo el 8,9% posee alguna titulación deportiva. Además, la mayoría elige los deportes individuales y prefiere practicar por su cuenta con los amigos, utilizando los lugares públicos y los clubes o gimnasios privados para la práctica. Palabras-clave

    Effect of gelled inner aqueous phase rheology on the colour degradation of muitle aqueous extracts incorporated into water-in-oil-in-water double emulsions

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    The aim of this work was to study different W1/O/W2 double emulsions in preserving color muitle aqueous extract (MAE), for which the work was divided into two fold, formulation and analysis of primary emulsion W1/O and W1/O/W2 double emulsions. Sodium alginate (SA), xanthan gum, guar gum, locust bean gum were used as gelling agents of MAE, and it was found that SA produced inner aqueous phase with enhanced viscoelastic properties, resulting in a W1/O primary emulsion with more uniform mean droplet size and distribution than when using the other gelling agents or ungelled MAE. Subsequently W1/O/W2 double emulsions were produced containing MAE gelled with SA or ungelled in the inner aqueous phase stabilized using pure gum Arabic (GA) or a blend of GA-mesquite gum (MG) in a 70:30 ratio in the outer aqueous phase. The double emulsion formulated with gelled MAE and 70:30 GA-MG blend exhibited more uniform mean inner water and outer oil droplet sizes, and protected best the anthocyanins contained in MAE to preserve its color when exposed to 8 h sunlight, providing a half-time life (t1/2) of 55.23 h. The double emulsion formulated with ungelled MAE and stabilized with pure GA displayed a t1/2 of 7.40 h. Keywords: double emulsions, muitle aqueous extract, gelling agents, viscoelastic properties, droplet size, half-time life

    Moisture sorption properties and storage stability conditions of a nutraceutical system microencapsulated by spray drying

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    The adsorption isotherms of a nutraceutical system microencapsulated by spray drying were determined at 20, 35 and 40 °C. Experimental data of the isotherms were fitted using the GAB and Caurie models and the integral thermodynamic functions (enthalpy and entropy) were estimated by the Clausius-Clapeyron equation. The Kelvin and Halsey equations were adequate for calculation of pore radius which varied from 0.67 to 8.15 nm. The point of maximum stability (minimum integral entropy) was found between 3.61 and 3.81 kg H2O/100 kg d.s. (corresponding to water activity, aW, of 0.19-0.37). Enthalpy-entropy compensation for the microcapsules showed two isokinetic temperatures. The first isokinetic temperature was observed at low moisture contents (< 3.81 kg H2O/100 kg d.s.) and was controlled by changes in the entropy of water, whereas the second isokinetic temperature was considered to be enthalpy-driven (3.81-20 kg H2O/100 kg d.s.). Keywords: sorption isotherms, pore radius, minimum integral entropy, enthalphy-entropy compensation, water activity

    Pharmacological blockade of either cannabinoid CB1 or CB2 receptors prevents both cocaine-induced conditioned locomotion and cocaine-induced reduction of cell proliferation in the hippocampus of adult male rats

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    Addiction to major drugs of abuse, such as cocaine, has recently been linked to alterations in adult neurogenesis in the hippocampus. The endogenous cannabinoid system modulates this proliferative response as demonstrated by the finding that pharmacological activation/blockade of cannabinoid CB1 and CB2 receptors not only modulates neurogenesis but also modulates cell death in the brain. In the present study, we evaluated whether the endogenous cannabinoid system affects cocaine-induced alterations in cell proliferation. To this end, we examined whether pharmacological blockade of either CB1 (Rimonabant, 3 mg/kg) or CB2 receptors (AM630, 3 mg/kg) would affect cell proliferation (the cells were labeled with BrdU) in the subventricular zone (SVZ) of the lateral ventricle and the dentate subgranular zone (SGZ). Additionally, we measured cell apoptosis (as monitored by the expression of cleaved caspase-3) and glial activation (by analyzing the expression of GFAP and Iba-1) in the striatum and hippocampus during acute and repeated (4 days) cocaine administration (20 mg/kg). The results showed that acute cocaine exposure decreased the number of BrdU-immunoreactive (ir) cells in the SVZ and SGZ. In contrast, repeated cocaine exposure reduced the number of BrdU-ir cells only in the SVZ. Both acute and repeated cocaine exposure increased the number of cleaved caspase-3-, GFAP- and Iba1-ir cells in the hippocampus, and this effect was counteracted by AM630 or rimonabant, which increased the number of BrdU-, GFAP- and Iba1-ir cells in the hippocampus. These results indicate that the changes in neurogenic, apoptotic and gliotic processes that were produced by repeated cocaine administration were normalized by pharmacological blockade of CB1 and CB2. The restorative effects of cannabinoid receptor blockade on hippocampal cell proliferation were associated with the prevention of the induction of conditioned locomotion but not with the prevention of cocaine-induced sensitization.Fil: Blanco Calvo, Eduardo. Universitat de Lleida; EspañaFil: Rivera, Patricia. Universidad de Malaga; EspañaFil: Arrabal, Sergio. Universidad de Malaga; EspañaFil: Vargas, Antonio. Universidad de Malaga; EspañaFil: Pavon, Francisco Javier. Universidad de Malaga; EspañaFil: Serrano, Antonia. Universidad de Malaga; EspañaFil: Castilla Ortega, Estela. Universidad de Malaga; EspañaFil: Galeano, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas (i); ArgentinaFil: Rubio, Leticia. Universidad de Malaga; EspañaFil: Suaréz, Juan. Universidad de Malaga; EspañaFil: Rodríguez de Fonseca, Fernando. Universidad de Malaga; Españ

    Pharmacological blockade of either cannabinoid CB1 or CB2 receptors prevents both cocaine-induced conditioned locomotion and cocaine-induced reduction of cell proliferation in the hippocampus of adult male rats

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    Addiction to major drugs of abuse, such as cocaine, has recently been linked to alterations in adult neurogenesis in the hippocampus. The endogenous cannabinoid system modulates this proliferative response as demonstrated by the finding that pharmacological activation/blockade of cannabinoid CB1 and CB2 receptors not only modulates neurogenesis but also modulates cell death in the brain. In the present study, we evaluated whether the endogenous cannabinoid system affects cocaine-induced alterations in cell proliferation. To this end, we examined whether pharmacological blockade of either CB1 (Rimonabant, 3 mg/kg) or CB2 receptors (AM630, 3 mg/kg) would affect cell proliferation (the cells were labeled with BrdU) in the subventricular zone (SVZ) of the lateral ventricle and the dentate subgranular zone (SGZ). Additionally, we measured cell apoptosis (as monitored by the expression of cleaved caspase-3) and glial activation (by analyzing the expression of GFAP and Iba-1) in the striatum and hippocampus during acute and repeated (4 days) cocaine administration (20 mg/kg). The results showed that acute cocaine exposure decreased the number of BrdU-immunoreactive (ir) cells in the SVZ and SGZ. In contrast, repeated cocaine exposure reduced the number of BrdU-ir cells only in the SVZ. Both acute and repeated cocaine exposure increased the number of cleaved caspase-3-, GFAP- and Iba1-ir cells in the hippocampus, and this effect was counteracted by AM630 or rimonabant, which increased the number of BrdU-, GFAP- and Iba1-ir cells in the hippocampus. These results indicate that the changes in neurogenic, apoptotic and gliotic processes that were produced by repeated cocaine administration were normalized by pharmacological blockade of CB1 and CB2. The restorative effects of cannabinoid receptor blockade on hippocampal cell proliferation were associated with the prevention of the induction of conditioned locomotion but not with the prevention of cocaine-induced sensitization.Fil: Blanco Calvo, Eduardo. Universitat de Lleida; EspañaFil: Rivera, Patricia. Universidad de Malaga; EspañaFil: Arrabal, Sergio. Universidad de Malaga; EspañaFil: Vargas, Antonio. Universidad de Malaga; EspañaFil: Pavon, Francisco Javier. Universidad de Malaga; EspañaFil: Serrano, Antonia. Universidad de Malaga; EspañaFil: Castilla Ortega, Estela. Universidad de Malaga; EspañaFil: Galeano, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas (i); ArgentinaFil: Rubio, Leticia. Universidad de Malaga; EspañaFil: Suaréz, Juan. Universidad de Malaga; EspañaFil: Rodríguez de Fonseca, Fernando. Universidad de Malaga; Españ

    Ferromagnetic resonance for the quantification of superparamagnetic iron oxide nanoparticles in biological materials

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    The aim of the present work is the presentation of a quantification methodology for the control of the amount of superparamagnetic iron oxide nanoparticles (SPIONs) administered in biological materials by means of the ferromagnetic resonance technique (FMR) applied to studies both in vivo and in vitro. The in vivo study consisted in the analysis of the elimination and biodistribution kinetics of SPIONs after intravenous administration in Wistar rats. The results were corroborated by X-ray fluorescence. For the in vitro study, a quantitative analysis of the concentration of SPIONs bound to the specific AC133 monoclonal antibodies was carried out in order to detect the expression of the antigenic epitopes (CD133) in stem cells from human umbilical cord blood. In both studies FMR has proven to be an efficient technique for the SPIONs quantification per volume unit (in vivo) or per labeled cell (in vitro)

    Quesungual slash and mulch agroforestry system (QSMAS): Improving crop water productivity, food security and resource quality in the sub-humid tropics

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    The knowledge and principles generated by CPWF-PN15 confirm that QSMAS can be a model production system for implementing conservation agriculture to achieve food security and sustainable development in drought-prone areas of hillsides in the sub-humid tropics, while providing ecosystem services in the face of land degradation and climate change. As an adoptable option to replace the slash and burn traditional system, QSMAS can improve smallholder livelihoods through eco-efficient use and conservation of natural resources. Participatory validation activities suggest that the conservation agriculture principles embedded in QSMAS can be readily accepted by resource- poor farmers and local authorities in similar agroecosystems

    Preparing Phase 4 of the n_TOF/CERN facility

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    After CERN's Long Shutdown 2, the n_TOF facility infrastructure was largely upgraded. The biggest change is the installation of a new lead spallation target, the performance of which needs to be carefully examined. During Summer 2021, the facility's two flight paths were characterised in terms of neutron beam energy distribution, profile and resolution. In this work, the characterisation of the facility is described and the first results are given
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