30 research outputs found

    Probing the catalytic activity of sulfate-derived Pristine and post-treated porous TiO2(101) anatase mesocrystals by the oxidative desulfurization of dibenzothiophenes

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    Mesocrystals (basically nanostructures showing alignment of nanocrystals well beyond crystal size) are attracting considerable attention for modeling and optimization of functionalities. However, for surface-driven applications (heterogeneous catalysis), only those mesocrystals with excellent textural properties are expected to fulfill their potential. This is especially true for oxidative desulfuration of dibenzothiophenes (hard to desulfurize organosulfur compounds found in fossil fuels). Here, we probe the catalytic activity of anatases for the oxidative desulfuration of dibenzothiophenes under atmospheric pressure and mild temperatures. Specifically, for this study, we have taken advantage of the high stability of the (101) anatase surface to obtain a variety of uniform colloidal mesocrystals (approximately 50 nm) with adequate orientational order and good textural properties (pores around 3-4 nm and surface areas around 200 m2/g). Ultimately, this stability has allowed us to compare the catalytic activity of anatases that expose a high number of aligned single crystal-like surfaces while differing in controllable surface characteristics. Thus, we have established that the type of tetrahedral coordination observed in these anatase mesocrystals is not essential for oxidative desulfuration and that both elimination of sulfates and good textural properties significantly improve the catalytic activity. Furthermore, the most active mesocrystals have been used to model the catalytic reaction in three-(oil-solvent-catalyst) and two-phase (solvent-catalyst) systems. Thus, we have been able to observe that the transfer of DBT from the oil to the solvent phase partially limits the oxidative process and to estimate an apparent activation energy for the oxidative desulfuration reaction of approximately 40 kJ/mol in the two-phase system to avoid mass transfer limitations. Our results clearly establish that (101) anatase mesocrystals with excellent textural properties show adequate stability to withstand several post-treatments without losing their initial mesocrystalline character and therefore could serve as models for catalytic processes different from the one studied here.Fil: Rivoira, Lorena Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigación y Tecnología Química. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación y Tecnología Química; ArgentinaFil: Martinez, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación en Nanociencia y Nanotecnología; ArgentinaFil: Falcon, Horacio. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación en Nanociencia y Nanotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Beltramone, Andrea Raquel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación en Nanociencia y Nanotecnología; ArgentinaFil: Campos-Martin, Jose M.. Consejo Superior de Investigaciones Científicas; EspañaFil: García Fierro, José Luis. Instituto de Catalisis y Petroleoquimica-csic; EspañaFil: Tartaj, Pedro. Consejo Superior de Investigaciones Científicas. Instituto de Catálisis y Petroleoquímica; Españ

    Evaluation of Natural Technological Interfaces for Children with Psychomotor Disabilities

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    population with disabilities, there is a group that has intellectual, sensory, motor disabilities, or a combination of them. The International Classification of Functioning, Disability and Health (ICF) defines disability as an umbrella term for impairments, activity limitations and participation restrictions. It is estimated that over 15 % of the world´s population is afflicted by disability in some form. In Argentina this prevalence reaches 7.1%. When these people want to use any technological device, usually find that its physical interfaces are not accessible. Often they need adaptations, raising costs but accessibility is not totally guaranteed. Current technologies allow "more natural" interfaces, where the feedback is immediate. The application of appropriate technology with natural or intuitive interfaces, allow greater accessibility than adaptations commonly used for the overall development of students with psychomotor disorders. The objective of this work is to facilitate the comprehensive development of students with senso psychomotor disorders attending the Special School Beatriz Martinez A. Allio, through the incorporation and implementation of natural interfaces for working with computers in education, offering teaching a complementary tool for the development of their daily activities. The interfaces of hardware and software implementation are proposed to achieve the overall goal. It is intended to make at least a touch screen and at least one interface with the Kinect camera game console Xbox 360.Fil: Beltramone, D. A. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Ingeniería Biomédica; Argentina.Fil: Tula, S. M. Ministerio de Educación de la Provincia de Córdoba. Escuela Especial B. A. Martínez Allio; Argentina.Fil: Rivarola, M. F. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Escuela Kinesiología y Fisioterapia; Argentina.Fil: Hidalgo, M. B. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Ingeniería Biomédica; Argentina.Fil: Tancredi, P. D. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Ingeniería Biomédica; Argentina.Fil: Quinteros Quintana, M. L. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Ingeniería Biomédica; Argentina.Fil: Diaz, J. M. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Ingeniería Biomédica; Argentina.Fil: Marcotti, A. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Ingeniería Biomédica; Argentina.Fil: Atea, J. J. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Electrónica; Argentina.Ingeniería Médic

    α-Synuclein is a Novel Microtubule Dynamase.

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    α-Synuclein is a presynaptic protein associated to Parkinson's disease, which is unstructured when free in the cytoplasm and adopts α helical conformation when bound to vesicles. After decades of intense studies, α-Synuclein physiology is still difficult to clear up due to its interaction with multiple partners and its involvement in a pletora of neuronal functions. Here, we looked at the remarkably neglected interplay between α-Synuclein and microtubules, which potentially impacts on synaptic functionality. In order to identify the mechanisms underlying these actions, we investigated the interaction between purified α-Synuclein and tubulin. We demonstrated that α-Synuclein binds to microtubules and tubulin α2β2 tetramer; the latter interaction inducing the formation of helical segment(s) in the α-Synuclein polypeptide. This structural change seems to enable α-Synuclein to promote microtubule nucleation and to enhance microtubule growth rate and catastrophe frequency, both in vitro and in cell. We also showed that Parkinson's disease-linked α-Synuclein variants do not undergo tubulin-induced folding and cause tubulin aggregation rather than polymerization. Our data enable us to propose α-Synuclein as a novel, foldable, microtubule-dynamase, which influences microtubule organisation through its binding to tubulin and its regulating effects on microtubule nucleation and dynamics

    Estudio de base ambiental en Cerro Blanco, departamento Calamuchita, Córdoba

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    Fil: Toledo, José M. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Fil: Beltramone, Giuliana. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Fil: Cejas, Gabriela. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Fil: Toledo, Graciela. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Cerro Blanco es un antiguo yacimiento de mica y berilio, que contiene una serie de minas, registradas bajo el nombre de “Julio Cesar” y que fueron intensamente explotadas años atrás. El cerro está ubicado al oeste del paraje El Durazno, en cercanías de Villa Yacanto, Dpto. Calamuchita, a una altura de entre los 1700 y 2300 msnm, y comprende cerca de 42 km2 .www.asadep.com.arFil: Toledo, José M. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Fil: Beltramone, Giuliana. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Fil: Cejas, Gabriela. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Fil: Toledo, Graciela. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Conservación de la Biodiversida

    Influence of Ti Incorporation to Bimetallic Mesoporous Carbon in the Production of 2,5-Dimethylfuran from Biomass Derivatives

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    Monometallic and bimetallic supported catalysts were developed to produce 2,5-dimethylfuran (DMF) trough hydrogenolysis of 5-(hydroxymethyl)furfural (HMF). Detailed physicochemical characterization was done to understand structure–activity correlation. Through a series of experiments and comparatives tests, the synergistic effect among Pt, Ir, and Ti incorporated in the support was investigated. Results revealed that using the titanium contained ordered mesoporous carbon, synthesized by a novel technique, high selectivity to DMF was achieved. In the case of the best catalyst PtIr-TiC, the good activity and excellent selectivity to the desired product DMF (98% yield) was related to the high hydrogenating capacity of the bimetallic sites, the acid support characteristics and the high metal nanoparticles dispersion achieved on the mesoporous titanium modified carbon support.NANOTEC, CONICET, Universidad Tecnológica Nacional, Maestro López y Cruz Roja Argentina. We acknowledge the financial support provided by CONICET Argentina, PIP CONICET 11220120100218CO 2020. M.E.D thanks Spanish Government financial support (CTQ2015-67592 and PGC2018-097277-B-I00)Peer reviewe

    Influence of Ti Incorporation to Bimetallic Mesoporous Carbon in the Production of 2,5-Dimethylfuran from Biomass Derivatives

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    [EN] Monometallic and bimetallic supported catalysts were developed to produce 2,5-dimethylfuran (DMF) trough hydrogenolysis of 5-(hydroxymethyl)furfural (HMF). Detailed physicochemical characterization was done to understand structure-activity correlation. Through a series of experiments and comparatives tests, the synergistic effect among Pt, Ir, and Ti incorporated in the support was investigated. Results revealed that using the titanium contained ordered mesoporous carbon, synthesized by a novel technique, high selectivity to DMF was achieved. In the case of the best catalyst PtIr-TiC, the good activity and excellent selectivity to the desired product DMF (98% yield) was related to the high hydrogenating capacity of the bimetallic sites, the acid support characteristics and the high metal nanoparticles dispersion achieved on the mesoporous titanium modified carbon support.NANOTEC, CONICET, Universidad Tecnologica Nacional, Maestro Lopez y Cruz Roja Argentina. We acknowledge the financial support provided by CONICET Argentina, PIP CONICET 11220120100218CO 2020. M.E.D thanks Spanish Government financial support (CTQ2015-67592 and PGC2018-097277-B-I00).Ledesma, BC.; Juárez, JM.; Domine, ME.; Beltramone, AR. (2022). Influence of Ti Incorporation to Bimetallic Mesoporous Carbon in the Production of 2,5-Dimethylfuran from Biomass Derivatives. Catalysis Letters. 152(5):1530-1544. https://doi.org/10.1007/s10562-021-03711-815301544152

    Novel and simple one-pot method for the synthesis of TiO 2 modified-CMK-3 applied in oxidative desulfurization of refractory organosulfur compounds

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    Ti-CMK-3 carbon mesoporous was prepared using a novel synthesis method. This new method avoids the hard template synthesis used commonly. The precursors of silicon, carbon and titanium are incorporated together with the other components during the only step of the synthesis. The method developed here, allows reducing time and energy consumption by 60% and thus, the cost of the overall process of synthesis. Structural and textural characterization of the titanium modified-mesoporous carbon was performed by N2 adsorption, XRD, UV–Vis-DRS, XPS, Raman spectroscopy and TEM. The characterization results indicated that the textural and structural properties of the material synthesized by the short time method are comparable with the properties of the material prepared by the hard template method. Ti modified-mesoporous carbon was synthesized by different methods in order to prepare catalysts to be tested in the oxidative desulfurization (ODS) of sulfur compounds. The catalyst prepared by the one-pot method is capable to oxidize high amount of sulfur (2000 ppm) in only 30 min of reaction time at 60–80 °C. The good performance and stability of the catalyst prepared using a novel synthesis method was attributed to well dispersed anatase nanospecies over the high area mesoporous carbon. Main advantage of the present study is the reduction of time and cost in the synthesis of the new material and the applicability for ODS reactions.Fil: Rivoira, Lorena Paola. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación en Nanociencia y Nanotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Ledesma, Brenda Cecilia Soledad. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación en Nanociencia y Nanotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Juárez, Juliana M.. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación en Nanociencia y Nanotecnología; ArgentinaFil: Beltramone, Andrea Raquel. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación en Nanociencia y Nanotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentin
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