95 research outputs found

    ELS ANYS SENSE CONSILIARI. 1972 A 1981

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    Estudio de la calidad de uvas de la variedad Bobal según el tipo de racimo y la posición de las bayas

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    López- Cortés, I.; Gandía, I.; Díaz, P.; Salazar Hernández, DM. (2021). Estudio de la calidad de uvas de la variedad Bobal según el tipo de racimo y la posición de las bayas. La Semana Vitivinicola. (3601):1737-1744. http://hdl.handle.net/10251/18972717371744360

    Preferential oxidation of CO over Au/CuOx-CeO2 catalyst in microstructured reactors studied through CFD simulations

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    A computational fluid dynamics (CFD) simulation study of the preferential oxidation of CO (CO-PROX) in microstructured reactors consisting in square and semicircular microchannels coated with anAu/CuOx¿CeO2catalyst is presented. The CO content of the feed stream was set at 1 vol.%. A parametricsensitivity analysis has been performed under isothermal conditions revealing that an optimal reactiontemperature exists that leads to a minimum CO content at the microreactor exit. The influence of thespace velocity, CO2concentration and oxygen-to-CO molar ratio in the feed stream (), catalyst loading,and microchannel characteristic dimension (d) on the microreactor performance has been investigated.Under suitable conditions, the CO concentration can be reduced below 10 ppm at relatively low tem-peratures within the 155¿175¿C range. A negative effect of the increase of d from 0.35 mm to 2.8 mmon the CO removal efficiency has been found and attributed to a more detrimental effect of the masstransport limitations on the oxidation of CO than that of H2. Non-isothermal CFD simulations have beenperformed to investigate the cooling of the CO-PROX reactor with air or a fuel cell anode off gas surrogatein parallel microchannels. Due to the very rapid heat transfer allowed by the microreactor and the stronginfluence of the reaction temperature on the exit CO concentration, a careful control of the coolant flowrate and inlet temperature is required for proper reactor operation. The microreactor behavior is virtuallyisothermal.Peer Reviewe

    Preferential oxidation of CO over Au/CuOx-CeO2 catalyst in microstructured reactors studied through CFD simulations

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    A computational fluid dynamics (CFD) simulation study of the preferential oxidation of CO (CO-PROX) in microstructured reactors consisting in square and semicircular microchannels coated with anAu/CuOx¿CeO2catalyst is presented. The CO content of the feed stream was set at 1 vol.%. A parametricsensitivity analysis has been performed under isothermal conditions revealing that an optimal reactiontemperature exists that leads to a minimum CO content at the microreactor exit. The influence of thespace velocity, CO2concentration and oxygen-to-CO molar ratio in the feed stream (), catalyst loading,and microchannel characteristic dimension (d) on the microreactor performance has been investigated.Under suitable conditions, the CO concentration can be reduced below 10 ppm at relatively low tem-peratures within the 155¿175¿C range. A negative effect of the increase of d from 0.35 mm to 2.8 mmon the CO removal efficiency has been found and attributed to a more detrimental effect of the masstransport limitations on the oxidation of CO than that of H2. Non-isothermal CFD simulations have beenperformed to investigate the cooling of the CO-PROX reactor with air or a fuel cell anode off gas surrogatein parallel microchannels. Due to the very rapid heat transfer allowed by the microreactor and the stronginfluence of the reaction temperature on the exit CO concentration, a careful control of the coolant flowrate and inlet temperature is required for proper reactor operation. The microreactor behavior is virtuallyisothermal.Ministerio de Ciencia e Innovación ENE2009-14522-C04Ministerio de Economía y Competitividad ENE2012-37431-C0

    Preferential oxidation of CO (CO-PROX) over CuOx/CeO2 coated microchannel reactor

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    The general aspects of the synthesis and characterization results of a CuOx/CeO2 catalyst were presented. In addition the principal steps for manufacturing a microchannel reactor and for the coating of the CuOx/CeO2 catalyst onto the microchannels walls, were also summarized. The catalytic activity of this microchannel reactor during the preferential oxidation of CO (CO-PROX) was evaluated employing a feed-stream that simulates a reformate off-gas after the WGS unit. Two activation atmospheres were studied (H2/N2 and O2/N 2). The reducing pretreatment improved the resistance to deactivation by formation of carbonaceous species over the catalyst surface at high temperatures. The presence of H2O and CO2 in the feed-stream was also analyzed indicating that the adsorption of CO2 inhibited the conversion of CO at lower temperatures because these compounds modified the active sites through the formation of carbonaceous species on the catalyst surface. Finally, the experimental results of the microreactor performance were compared with CFD simulations that were carried out using a kinetic for the CuOx/CeO2 powder catalyst. The experimental results were reasonably well described by the model, thus confirming its validity.Peer Reviewe

    Tumores óseos de la pelvis

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    Se presenta la experiencia del Servicio de Ortopedia del Adulto del Hospital «Ramón y Cajal», en neoplasias de la pelvis, desde su creación hasta la actualidad, siendo 61 los pacientes recogidos y no se hace un trabajo estadístico, sino más bien se muestran las peculiaridades recogidas con la experiencia, que abarca desde la abstención en algunos casos de tumores secundarios, y el simple curetage hasta las grandes sustituciones con homoinjertos de banco, relacionándolo a su vez con publicaciones de aparición más o menos moderna sobre este tema, para concluir que se trata de una cirugía no exenta de complicaciones y problemas, pero necesaria a la hora de proporcionar a los enfermos curaciones, que le ofrezcan una salida a este difícil problema.The experience of Adult Orthopaedics Unit at the Hospital «Ramón y Cajal», Madrid, treating patients with malignant tumors of the pelvic bons is presented. In this paper, the results after surgery are not reported in terms of statistical analysis. The aún of this work is to comment the surgical experience covering from simple curettage to great bone replacement using bank allografts. The message is that surgical treatment of pelvic tumors is not exent of complications, but it seems to be worth in order to offer a better quality of Ufe for patients

    Supplementation of re-esterified docosahexaenoic and eicosapentaenoic acids reduce inflammatory and muscle damage markers after exercise in endurance athletes: a randomized, controlled crossover trial

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    This study aimed to analyse the e ect of 10 weeks of a highly concentrated docosahexaenoic acid (DHA) + eicosapentaenoic (EPA) supplementation (ratio 8:1) on strength deficit and inflammatory and muscle damage markers in athletes. Fifteen endurance athletes participated in the study. In a randomized, double-blinded cross-over controlled design, the athletes were supplemented with a re-esterified triglyceride containing 2.1 g/day of DHA + 240 mg/day of EPA or placebo for 10 weeks. After a 4-week wash out period, participants were supplemented with the opposite treatment. Before and after each supplementation period, participants performed one eccentric-induced muscle damage exercise training session (ECC). Before, post-exercise min and 24 and 48 h after exercise, muscle soreness, knee isokinetic strength and muscle damage and inflammatory markers were tested. No significant differences in strength deficit variables were found between the two conditions in any of the testing sessions. However, a significant effect was observed in IL1 (p = 0.011) and IL6 (p = 0.009), which showed significantly lower values after DHA consumption than after placebo ingestion. Moreover, a significant main effect was observed in CPK (p = 0.014) and LDH-5 (p = 0.05), in which significantly lower values were found after DHA + EPA consumption. In addition, there was a significant effect on muscle soreness (p = 0.049), lower values being obtained after DHA + EPA consumption. Ten weeks of re-esterified DHA + EPA promoted lower concentrations of inflammation and muscle damage markers and decreased muscle soreness but did not improve the strength deficit after an ECC in endurance athletes

    Selective CO removal over Au/CeFe and CeCu catalysts in microreactors studied through kinetic analysis and CFD simulations

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    A kinetic study of the preferential oxidation of CO in H2 rich streams (CO-PrOx) over a cerium-copper oxide (CeCu) and a gold catalyst supported on cerium-iron oxide (Au/CeFe) is presented. The gold catalyst is very active but the CeCu oxide is more selective. A kinetic model describing the CO-PrOx system with CO2 and H2O in the feed has been formulated considering the oxidation of CO and H2 and the reverse water-gas shift reaction. The rate equations have been implemented in computational fluid dynamics codes to study the influence of the operating variables on the CO-PrOx in microchannels and microslits. The CeCu catalyst is the only one capable of achieving final CO contents below 10-100ppmv. Due to the opposite effect of temperature on activity and selectivity there is an optimal temperature at which the CO content is minimal over CeCu. This temperature varies between 170 and 200°C as the GHSV increases from 10,000 to 50,000h-1. Simulations have evidenced the very good heat transfer performance of the microdevices showing that the CO-PrOx temperature can be controlled using air as cooling fluid although the inlet temperature and flow rate should be carefully controlled to avoid reaction extinction. Both microchannels and microslits behaved similarly. The fact that the microslits are much easier to fabricate may be an interesting advantage in favour of that geometry in this case.Ministerio de Ciencia e Innovación MAT2006-12386-C05, ENE2009-14522-C0

    Characterization of electrochemical systems using potential step voltammetry. Part II: Modeling of reversible systems

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    [EN] This study was carried out to compare the results obtained using potential step voltammetry and linear sweep voltammetry with a rotating gold disc electrode (RDE), when models based on equivalent circuits (EC) were used. The results lead to an equivalent circuit model that allows us to interpret the electrochemical behavior of aqueous solutions containing Fe(CN)(6)(-4) and Fe(CN)(6)(-3). With this model, we determined the values of the electrical resistance of the medium (R-s) as well as its polarization resistance (R-p), and established correlations between these values and the kinetic parameters of the system. The proposal highlights the need to introduce a new component for modeling using EC, which we have called the electrochemical diode. (C) 2019 Elsevier Ltd. All rights reserved.The authors gratefully acknowledge the financial support of BIA2016-78460-C3-3-R, MAT2015-64139-C4-3-R and RTI2018-100910-B-C43 (MINECO/FEDER) projects. We would also like to extend our appreciation for the pre-doctoral FPU scholarships (University Teacher Training scholarship) granted to Ana Martinez Ibernon (FPU 16/00723) and Jose Enrique Ramon Zamora (FPU13/00911) by the Spanish Ministry of Science and Innovation.Martínez-Ibernón, A.; Ramón Zamora, JE.; Gandía-Romero, JM.; Gasch, I.; Valcuende Payá, MO.; Alcañiz Fillol, M.; Soto Camino, J. (2019). Characterization of electrochemical systems using potential step voltammetry. Part II: Modeling of reversible systems. Electrochimica Acta. 328:1-10. https://doi.org/10.1016/j.electacta.2019.135111S11032

    Targeting Alzheimer’s disease with multimodal polypeptide-based nanoconjugates

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    Alzheimer’s disease (AD), the most prevalent form of dementia, remains incurable mainly due to our failings in the search for effective pharmacological strategies. Here, we describe the development of targeted multimodal polypeptide-based nanoconjugates as potential AD treatments. Treatment with polypeptide nanoconjugates bearing propargylamine moieties and bisdemethoxycurcumin or genistein afforded neuroprotection and displayed neurotrophic effects, as evidenced by an increase in dendritic density of pyramidal neurons in organotypic hippocampal culture. The additional conjugation of the Angiopep-2 targeting moiety enhanced nanoconjugate passage through the blood-brain barrier and modulated brain distribution with nanoconjugate accumulation in neurogenic areas, including the olfactory bulb. Nanoconjugate treatment effectively reduced neurotoxic amyloid aggregate levels and rescued impairments to olfactory memory and object recognition in APP/PS1 transgenic AD model mice. Overall, this study provides a description of a targeted multimodal polyglutamate-based nanoconjugate with neuroprotective and neurotrophic potential for AD treatment. Copyrigh
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