1,021 research outputs found

    An update of biocatalytic selective acylation and deacylation of monosaccharides

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    Partially acylated monosaccharides (PAMs) exhibit diverse and interesting applications but due to their polyhydroxylated nature, their synthesis requires regio- and stereoselective reactions. These features are provided by biocatalytic processes and in particular by hydrolases, which offer mild conditions and selective routes for the preparation of PAMs. Since this strategy has been extensively explored, the aim of the present review is to update research on enzymatic selective acylation and deacylation of monosaccharides, focusing on enzymatic preparation of synthetic useful PAMs and drug–monosaccharide conjugates involving PAMs.Fil: Iribarren, Adolfo Marcelo. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Área Química. Laboratorio de Biotransformaciones; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Iglesias, Luis Emilio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Área Química. Laboratorio de Biotransformaciones; Argentin

    Candida antarctica B lipase-catalysed alcoholysis of peracetylated alkyl D-ribofuranosides

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    Candida antarctica B lipase (CAL-B) catalysed alcoholysis of a series of peracetylated alkyl α, β-D-ribofuranosides was assayed. Methyl and ethyl 2,3-di-O-acetyl-α, β-D-ribofuranosides enriched in the α-anomer were regioselectively prepared through this enzymatic deacetylation in 33% and 43% yield, respectively, the latter being a new compound. Isopropyl 2,3,5-tri-O-acetyl-β-D-ribofuranoside gave the new isopropyl 2,3-di-O-acetyl-β-D-ribofuranoside in 24% yield. The anomeric substituent affects the regioselectivity of the reaction, since n-propyl and n-butyl α, β-D-ribofuranosides reacted without selectivity.Fil: Gudiño, Esteban Dario. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Iribarren, Adolfo Marcelo. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Iglesias, Luis Emilio. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Regioselectivity of Lipase-Catalysed Deacetylation of Methyl 2,3,5-tri-OAcetyl-α, β-D-Furanosides in Ionic Liquid

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    Ionic liquids (ILs) were assayed as reaction medium for the enzymatic deacetylation of three methyl 2,3,5-tri-O-acetyl-a,b-D-furanosides and the obtained results show the influence of the IL and the furanose structure on the regioselectivity of hydrolyses catalysed by the tested lipases. In a reaction medium consisting of a 1:1 mixture of 30 mM phosphate buffer (pH 7) and 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]), Candida rugosa lipase catalysed the formation of methyl 2,3-di-O-acetyl-a,b-D-arabinofuranoside in 77 %, while in a 9:1 mixture of the same buffer and 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]), methyl 2,3-di-O-acetyl-a,b-D-ribofuranoside was obtained in 62 %.Fil: Gudino, Esteban D.. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Área Química. Laboratorio de Biotransformaciones; ArgentinaFil: Iribarren, Adolfo Marcelo. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Área Química. Laboratorio de Biotransformaciones; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Iglesias, Luis Emilio. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Área Química. Laboratorio de Biotransformaciones; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    An improved regioselective preparation of methyl 2,3-di-O-acetyl-α, β-d-xylofuranoside

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    Methyl 2,3-di-O-acetyl-α,β-d-xylofuranoside was prepared as the sole regioisomer in 6372% yield, according to the applied mass of substrate, through a Candida antarctica lipase B catalysed alcoholysis of methyl 2,3,5-tri-O-acetyl-α,β-d-xylofuranoside. The product is a potential synthetic precursor for 5-modified xylofuranosides and 5′-modified xylonucleosides.Fil: Gudiño, Esteban Dario. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Área Química. Laboratorio de Biotransformaciones; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Iribarren, Adolfo Marcelo. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Área Química. Laboratorio de Biotransformaciones; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Iglesias, Luis Emilio. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Área Química. Laboratorio de Biotransformaciones; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Analysis of Neutron Thermal Scattering Data Uncertainties in PWRs

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    Analysis of Neutron Thermal Scattering Data Uncertainties in PWR

    Interactive Graphic Simulation: An Advanced Methodology to Improve the Teaching-Learning Process in Nuclear Engineering Education and Training

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    Nowadays, computer simulators are becoming basic tools for education and training in many engineering fields. In the nuclear industry, the role of simulation for training of operators of nuclear power plants is also recognized of the utmost relevance. As an example, the International Atomic Energy Agency sponsors the development of nuclear reactor simulators for education, and arranges the supply of such simulation programs. Aware of this, in 2008 Gas Natural Fenosa, a Spanish gas and electric utility that owns and operate nuclear power plants and promotes university education in the nuclear technology field, provided the Department of Nuclear Engineering of Universidad Politécnica de Madrid with the Interactive Graphic Simulator (IGS) of “José Cabrera” (Zorita) nuclear power plant, an industrial facility whose commercial operation ceased definitively in April 2006. It is a state-of-the-art full-scope real-time simulator that was used for training and qualification of the operators of the plant control room, as well as to understand and analyses the plant dynamics, and to develop, qualify and validate its emergency operating procedures

    Education and Training of Future Nuclear Engineers Through The use of An Interactive Plant Simulator.

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    The International Atomic Energy Agency (IAEA) sponsors the development of nuclear reactor simulators for education, or arranges the supply of such simulation programs [1]. Aware of this, the Department of Nuclear Engineering of the Universidad Politécnica de Madrid was provided in 2008 with the Interactive Graphical Simulator of the Spanish nuclear power plant José Cabrera, whose operation ceased definitively in 2006. According with the IAEA-TECDOC-1411 [2] , the simulator is a Graphical Simulator, used for training of main control room personnel, technical support engineers, and operations management. This paper presents all the work performed at the Department to turn the simulator into a teaching/learning tool, to be use in the nuclear engineering studies following guidance found in [3]

    Effect of hyoscine butylbromide on cervical dilation during labor

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    To compare the effects of intravenous hyoscine butylbromide versus placebo on the duration of labor in term pregnancies. Materials and methods: 86 patients were selected and randomly assigned to receive intravenous hyoscine butylbromide (20 mg twice) (n = 43) or an intravenous placebo (saline solution 10 cc) (n = 43). We evaluated maternal adverse effects, effects on neonatal Apgar score, cervical dilatation 1 h after drug administration and the interval between the onset of labor and delivery. Results: No significant differences were observed in the duration of phases of labor between the two groups. No significant differences were found between the groups in Apgar scores at 1 and 5 min. No maternal adverse effects were observed or reported due to the use of hyoscine butylbromide or the placebo. On the first phase of primigravidas it shortens the first labor phase up to 159.1 ± 84 min vs. the control group (p = 0.002). Conclusion: Hyoscine butylbromide oxytocin shortens the duration of labor in term primigravida pregnancies. No side effects were reported

    Education and Training of Future Nuclear Engineers at DIN: From Advanced Computer Codes to an Interactive Plant Simulator.

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    This paper summarizes the work being performed at the Department of Nuclear Engineering (www.din.upm.es) of the Universidad Politécnica de Madrid to improve the education and training of future Spanish nuclear engineers according to the Bologna rules. We present two main efforts introduced in our programme: i) the understanding of the current computational methodologies/codes starting from the nuclear data processing, then the lattice and core calculations codes, and finally the power plant simulators, ii) the development of practical teaching-learning experiences with an Interactive Graphical Simulator of a real nuclear power plant

    Formación y entrenamiento de ingenieros nucleares mediante el máster de Ciencia y Tecnología nuclear de la UPM

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    El Departamento de Ingeniería Nuclear imparte los Programas oficiales de Máster y Doctorado en Ciencia y Tecnología Nuclear, que cuentan desde el año 2006 con la Mención de Calidad del Ministerio de Educación y desde este curso 2010-2011con la Mención a la Excelencia. El contenido del Máster abarca desde la tecnología nuclear de los reactores de fisión hasta el estudio de los combustibles y materiales para los futuros reactores de fusión tanto inercial como magnética
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