8 resultados para 13077-021

em Archivo Digital para la Docencia y la Investigación - Repositorio Institucional de la Universidad del País Vasco


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[EN] The aims of this work were (i) to evaluate the potential of nanostructured lipid carriers (NLCs) as a tool to 24 enhance the oral bioavailability of poorly soluble compounds using saquinavir (SQV), a BCS class IV drug 25 and P-gp substrate as a model drug, and (ii) to study NLC transport mechanisms across the intestinal barrier. 26 Three different NLC formulations were evaluated. SQV transport across Caco-2 monolayers was enhanced up 27 to 3.5-fold by NLCs compared to SQV suspension. M cells did not enhance the transport of NLCs loaded with 28 SQV. The size and amount of surfactant in the NLCs influenced SQV's permeability, the transcytosis pathway 29 and the efflux of SQV by P-gp. An NLC of size 247 nm and 1.5% (w/v) surfactant content circumvented P-gp 30 efflux and used both caveolae- and clathrin-mediated transcytosis, in contrast to the other NLC formulations, 31 which used only caveolae-mediated transcytosis. By modifying critical physicochemical parameters of the 32 NLC formulation, we were thus able to overcome the P-gp drug efflux and alter the transcytosis mechanism 33 of the nanoparticles. These findings support the use of NLCs approaches for oral delivery of poorly 34 water-soluble P-gp substrates.

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In order to analyse the possibilities of improving grid stability on island systems by local demand response mechanisms,a multi-agent simulation model is presented. To support the primary reserve, an under-frequency load shedding (UFLS)using refrigerator loads is modelled. The model represents the system at multiple scales, by recreating each refrigerator individually, and coupling the whole population of refrigerators to a model which simulates the frequency response of the energy system, allowing for cross-scale interactions. Using a simple UFLS strategy, emergent phenomena appear in the simulation. Synchronisation e ects among the individual loads were discovered, which can have strong, undesirable impacts on the system such as oscillations of loads and frequency. The phase transition from a stable to an oscillating system is discussed.

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[ES] El objetivo del presente artículo es demostrar y analizar las discrepancias que hubo en el seno de la burguesía guipuzcoana durante los siglos XVIII y XIX en torno a la habilitación de los puertos guipuzcoanos para el comercio directo con América y el traslado de aduanas desde el interior a la costa. Para ello, se acude a la extensa historiografía que se ha ocupado del tema y se hace un análisis crítico de cierto número de representaciones enviadas por el grupo de comerciantes disidentes, con el fin de llevar a cabo un reco- rrido por el debate en torno a ambas cuestiones, que se prolongó desde el advenimiento de la dinastía borbónica hasta los decretos de 1841. A pesar de la visión unívoca que se ha dado del mencionado debate, según la cual parti- ciparon dos bloques perfectamente diferenciados, la documentación muestra una mayor heterogeneidad en las posturas, de manera que en el seno de la burguesía comercial se perciben ciertas divisiones y discrepancias. Si bien es cierto que en un principio los bloques parecen tener un discurso claramente beligerante, aunque también existen todavía puntos de coincidencia, a medi- da que transcurre el tiempo, las posturas se van radicalizando y diversifi- cando, creando una mayor heterogeneidad.

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254 p : il, graf. col.

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This paper presents a theoretical and experimental study of multidirectional steel fibers reinforced concrete slabs (SFRC). The study is based on a real building application using SFRC flag slabs. For the evaluation of the slabs bearing capacity, plastic calculations are performed both at section and structure levels. The section analysis uses the perfect plastic stress-strain diagram, with reference to the values of the strength characteristics of SFRC based on previous jobs that used similar fibers and dosages. In the structure analysis the plastic yield lines method has been used. This method relates the section last bearing moment and the plastic collapse load. The experimental campaign has consisted of the testing of six 2 m. diameter circular shaped slabs prototypes, and has allowed to verify the reference resistance used in the calculations.

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Single-spin asymmetries were investigated in inclusive electroproduction of charged pions and kaons from transversely polarized protons at the HERMES experiment. The asymmetries were studied as a function of the azimuthal angle psi about the beam direction between the target-spin direction and the hadron production plane, the transverse hadron momentum P-T relative to the direction of the incident beam, and the Feynman variable x(F). The sin psi* amplitudes are positive for pi(+) and K+ slightly negative for pi(-) and consistent with zero for K-, with particular P-T but weak x(F) dependences. Especially large asymmetries are observed for two small subsamples of events, where also the scattered electron was recorded by the spectrometer. (C) 2013 The Authors. Published by Elsevier B.V. All rights reserved.