416 research outputs found

    Hydrophobically modified polyelectrolytes as potential drugs reservoirs of n-alkyl-nitroimidazoles

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    Indexación: ScieloThe solubilization of three commercial drugs (ornindazole, metronidazole and tinidazole) and model compounds (N-alkyl-2-methyl-4-nitroimidazoles) on aggregates formed by anionic polyelectrolytes, carrying alkyl side chains of different length, have been investigated in aqueous solution at pH 3.0, 7.0 and 11.0. Potassium salts of poly(maleic acid-co-1-olefins), PA-nK2 with n ranging from 8 to 18, were used as micelle-forming polymers. The partition of these drugs between water and the hydrophobic microdomains provided by PA-nK2 was studied by the pseudo-phase model to determinate the distribution coefficient KS, and the standard free energy of transfer Δμºt. The results indicate that solubility of alkyl-nitroimidazoles on these polymer micelles depends moderately on the length of the alkyl chain, and therefore is mainly determined by the heterocyclic group. On the other hand, the solubilization of 1-hexyl-2-methyl-4-nitroimidazole increase with decreasing length of the side alkyl chain; i.e. KS follows the order PA-8K2 > PA-10K2 > PA-12K2 > PA-14K2 > PA-16K2 >PA-18K2.http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-97072007000100014&nrm=is

    Kaizen–Kata, a Problem-Solving Approach to Public Service Health Care in Mexico. A Multiple-Case Study

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    3297Purpose: Mexico’s public hospitals are experiencing major operational problems which seriously a ect the care of Mexican citizens. Some hospitals have initiated e orts to apply the Kaizen philosophy to improve this situation. Therefore, the purpose of this article is to analyze the methodological impact of Kaizen–Kata implementation in Mexican public hospitals that have tried to solve operational problems using this improvement approach. Design/Methodology/Approach: The service organization implemented Kaizen–Kata methodology in order to improve one operational problem-process in health care. A case-study approach was used in this research in order to understand the e ects of the Kaizen–Kata methodology in solving problems in their operational procedures. Findings: Six specific drivers were identified when applying the Kaizen–Kata methodology. Furthermore, the impact on the levels of implementation of the Kaizen–Kata methodology in each of the improvement teams studied was also identified. Research Limitations: The main limitation of the research is that only three case-studies are presented thus it is not possible to generalize its results. Practical Implications (Where Possible): Other public hospitals can use this specific example as a working guide to solve the operational problems of health systems. Originality/Value: A methodology of continuous improvement in manufacturing was imported from the industry sector for application in an operational health care process. The Kaizen–Kata methodology contributed significantly to improving issues involving delays, customer complaints, process reworks and extra-cost, among other e ects of operational problems.S

    La institución de los Adelantados en América : Aportación al estudio de las magistraturas indianas

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    Sumario: —I. Breve reseña histórica de la institución de los Adelantados. —II. Diferentes clases de Adelantados. —III. Atribuciones propias de los Adelantados: a) Administración de justicia; b) Poder militar y de gobierno. —IV. Objeto de la creación del adelantazgo para América. —V. Los Adelantados en las Leyes de Indias. —VI. Casos en que está denunciado el ejercicio de las atribuciones de los Adelantados en América, tomados de grandes cronistas de Indias. —VII. Análisis crítico de las obras que tratan esta institución en América.Facultad de Humanidades y Ciencias de la Educació

    Analysis of thermal stresses in square ducts of solar receivers operated with liquid sodium

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    Implementación del “Kaizen-Innovación de Procesos-Jidoka” para hacer frente al COVID-19: un caso de estudio en un hospital público

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    Mexico’s public hospitals are experiencing major operational problems, such as process and service failure, as well as the lack of supplies and medical equipment. Some hospitals have started kaizen philosophy-based efforts to improve this situation. The main objective of the research is to explore the implementation of the kaizen philosophy in the above-mentioned hospitals. The research used a qualitative methodology and the case study strategy. The results show that it is feasible to optimize the Covid-19 emergency and treatment process by applying kaizen philosophy, process innovation and jidoka techniques.Los hospitales públicos de México están viviendo grandes problemas operativos, tales como fallos en los procesos y servicios, además de errores en la falta de insumos y equipo médico. Algunos hospitales han iniciado esfuerzos basados en la filosofía kaizen para mejorar esta situación. El objetivo principal de la investigación es explorar la implementación de la filosofía kaizen en hospitales públicos mexicanos. La metodología utilizada en esta investigación fue cualitativa, con la estrategia del caso deestudio. Los resultados encontrados en esta investigación son que es factible optimizar el proceso de urgencias y el de atención a la Covid-19 aplicando técnicas de la filosofía kaizen, innovación de procesos y jidoka

    Experimental semi-autonomous eigensolver using reinforcement learning

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    The characterization of observables, expressed via Hermitian operators, is a crucial task in quantum mechanics. For this reason, an eigensolver is a fundamental algorithm for any quantum technology. In this work, we implement a semi-autonomous algorithm to obtain an approximation of the eigenvectors of an arbitrary Hermitian operator using the IBM quantum computer. To this end, we only use single-shot measurements and pseudo-random changes handled by a feedback loop, reducing the number of measures in the system. Due to the classical feedback loop, this algorithm can be cast into the reinforcement learning paradigm. Using this algorithm, for a single-qubit observable, we obtain both eigenvectors with fidelities over 0.97 with around 200 single-shot measurements. For two-qubits observables, we get fidelities over 0.91 with around 1500 single-shot measurements for the four eigenvectors, which is a comparatively low resource demand, suitable for current devices. This work is useful to the development of quantum devices able to decide with partial information, which helps to implement future technologies in quantum artificial intelligence.Comment: 12 + 3 pages, 5 figure

    Particionado de elementos en dos carbones del sur-occidente colombiano

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    Se presentan los resultados del particionado de elementos al beneficiar dos carbones del Sur-Occidente Colombiano mediante separación ciclónica en medio denso. Las fracciones beneficiadas de carbón se obtuvieron empleando dos etapas de separación en serie. Tanto las fracciones de alimento de la primera etapa como las fracciones de fondo de la segunda etapa se analizaron por Fluorescencia de Rayos X (XRF) para determinar la concentración de 33 elementos. A partir de estos datos se determinó el factor de partición elemental con el fin de conocer su afinidad hacia las fases ricas en materia orgánica o materia mineral. Se encontró que cuando el tamaño de partícula de las fracciones de carbón disminuye se aumenta la afinidad de los elementos hacia la materia mineral

    Position Affects Performance in Multiple-Object Tracking in Rugby Union Players

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    We report an experiment that examines the performance of rugby union players and a control group composed of graduate student with no sport experience, in a multiple-object tracking task. It compares the ability of 86 high level rugby union players grouped as Backs and Forwards and the control group, to track a subset of randomly moving targets amongst the same number of distractors. Several difficulties were included in the experimental design in order to evaluate possible interactions between the relevant variables. Results show that the performance of the Backs is better than that of the other groups, but the occurrence of interactions precludes an isolated groups analysis. We interpret the results within the framework of visual attention and discuss both, the implications of our results and the practical consequences

    Estimating flooded area and mean water level using active and passive microwaves: the example of Paraná River Delta floodplain

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    This paper describes a procedure to estimate both the fraction of flooded area and the mean water level in vegetated river floodplains by using a synergy of active and passive microwave signatures. In particular, C band Envisat ASAR in Wide Swath mode and AMSR-E at X, Ku and Ka band, are used. The method, which is an extension of previously developed algorithms based on passive data, exploits also model simulations of vegetation emissivity. The procedure is applied to a long flood event which occurred in the Paraná River Delta from December 2009 to April 2010. Obtained results are consistent with in situ measurements of river water level
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