1,328 research outputs found

    Influencia de la segregación de Ti4+ en la respuesta multiferroica de materiales basados en BiFeO3

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    Los materiales multiferroicos han cobrado un interés creciente en los últimos años dada la potencialidad de sus aplicaciones prácticas. Los materiales basados en BiFeO3 pueden considerarse los más estudiados hasta la fecha dentro de los pocos multiferroicos conocidos. No obstante, sus propiedades aún no son adecuadas para su empleo en dispositivos pues suelen presentar una elevada conductividad eléctrica y/o una respuesta antiferromagnética. La modificación de estos materiales mediante dopado con Ti4+ puede disminuir las pérdidas dieléctricas y proporcionar un comportamiento ferromagnético. Sin embargo, los cambios producidos en la estructura, microestructura y propiedades de los materiales de BiFeO3 como consecuencia del dopado con Titanio no están claros. En este trabajo se presenta una caracterización detallada de cerámicas de composición nominal BiFe0.95Ti0.05O3 con una elevada resistencia y una respuesta magnética extraordinaria. Los resultados evidencian la formación de una nanoestructura relacionada con la segregación del dopante en borde de grano que es la responsable de los cambios producidos en las propiedades magnetoeléctricas de estos materiales

    Spatial search by continuous-time quantum walks on renormalized Internet networks

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    Publisher Copyright: © 2022 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.We study spatial search with continuous-time quantum walks on real-world complex networks. We use smaller replicas of the Internet network obtained with a recent geometric renormalization method introduced by García-Pérez, Nat. Phys. 14, 583 (2018)10.1038/s41567-018-0072-5. This allows us to infer for the first time the behavior of a quantum spatial search algorithm on a real-world complex network. By simulating numerically the dynamics and optimizing the coupling parameter, we study the optimality of the algorithm and its scaling with the size of the network, showing that on average it is considerably better than the classical scaling O(N), but it does not reach the ideal quadratic speedup O(N) that can be achieved, e.g. in complete graphs. However, the performance of the search algorithm strongly depends on the degree of the nodes and, in fact, the scaling is found to be very close to optimal when we consider the nodes below the 99th percentile ordered according to the degree.Peer reviewe

    Quality of cherry ‘Sweetheart’ from different regions of Portugal and Spain (Cova da Beira, Portalegre and Valle del Jerte).

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    Sweet cherries (Prunus avium L.) ‘Sweetheart’ were harvested at different production regions from Portugal (Cova da Beira and Portalegre) and Spain (Valle de Jerte). Cherries were harvested at their commercial maturation according to the empirical knowledge of external color corresponding to good quality. Fruits were stored and evaluated in order to study their quality on the harvest day and during a period of 21 days, at cold storage (1 ºC, 95% RH). The sweet cherry ‘Sweetheart’ is a well known variety and a highly appreciated one but fruits present a short shelf life. On the other hand the effect of different “terroir” on cherry characteristics should be known and clarified. Fruits from day 0, considered without storage, were kept at 20ºC and analyzed. Every weak, 3 replicas were randomly picked up and 10 fruits from each one were submitted to several analyses after fruit temperature stabilized at 20ºC. Several quality parameters were evaluated: external color (L*, a*, b*), texture, soluble solids content (SSC), titratable acidity (TA) and the ratio between soluble solid contents (SSC) and tritratable acidity (TA). Fruits from different orchards and locations were significantly different according to these parameters. Fruits from Cova da Beira were less firm comparing with other two regions, Valle de Jerte and Portalegre, which may indicate a higher maturation rate at harvest in those fruits. This is in accordance with SSC/titratable acidity rate suggesting a late harvest in Cova da Beira comparing with other two orchards, however fruits from Cova da Beira exhibit a poor color at harvest. These results clearly showed a lower correlation between SSC and firmness considering fruits origin

    Simple Sonochemical Method to Optimize the Heating Efficiency of Magnetic Nanoparticles for Magnetic Fluid Hyperthermia

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    We developed a fast, single-step sonochemical strategy for the green manufacturing of magnetite (Fe3O4) magnetic nanoparticles (MNPs), using iron sulfate (FeSO4) as the sole source of iron and sodium hydroxide (Na(OH)) as the reducing agent in an aqueous medium. The designed methodology reduces the environmental impact of toxic chemical compounds and minimizes the infrastructure requirements and reaction times down to minutes. The Na(OH) concentration has been varied to optimize the final size and magnetic properties of the MNPs and to minimize the amount of corrosive byproducts of the reaction. The change in the starting FeSO4concentration (from 5.4 to 43.1 mM) changed the particle sizes from (20 ± 3) to (58 ± 8) nm. These magnetite MNPs are promising for biomedical applications due to their negative surface charge, good heating properties (˜324 ± 2 W/g), and low cytotoxic effects. These results indicate the potential of this controlled, easy, and rapid ultrasonic irradiation method to prepare nanomaterials with enhanced properties and good potential for use as magnetic hyperthermia agents

    Sonochemical route for mesoporous silica-coated magnetic nanoparticles towards pH-triggered drug delivery system

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    This work reports a pH-triggered release system based on core@shell mesoporous magnetic nanoparticles (MNP@mSiO2) obtained using a simple and rapid ultrasound-assisted method. Performed characterization reveals magnetic cores of Fe2.9Mn0.1O4 (38 ± 6 nm) and specific loss power values adequate for hyperthermia (463 W/g), surrounded by a mesoporous silica shell (10 ± 2 nm) with large surface area (269 m2 g-1) functionalized with hydroxyl groups (-OH). MNP@mSiO2 were loaded with DOX and amino-silane grops, providing pH-triggered DOX release at acidic environments, driving by dipolar intermolecular interactions. The experimental DOX release kinetics at pH 5.5, 6.6 and 7.4 were determined and adjusted to Gompertz dissolution model (Nash–Sutcliffe efficiency coefficient (NSE>0.9)), where the only strongly pH-dependent variable is the percentage of DOX released. The pH-triggered response observed in the system was ~20% of the DOX loaded into the MNP@mSiO2 is released at pH 6.6 or 7.4, whereas up to 80 wt% is released at pH 5.5. Time to 50% of release and dissociation rate of the system remaining constant, suggesting no-pH influence on these parameters. The biological assays highlight negligible hemolytic effect and cytocompatibility of the hybrid material, pointing out the potential use of MNP@mSiO2 as a magnetic driven drug delivery system with pH-triggered drug release kinetics at acidic environments. These results probe the feasibility of sonochemical methods in the elaboration of biocompatible and controlled properties nanomaterials for drug release applications, with the advantage of accurately responses predictions by mathematical model and using minimal processing steps or laboratory equipment. © 2021 The Author

    Educación sanitaria en la farmacia comunitaria: estudio controlado en la provincia de Castellón

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    Introducción: La educación para la salud es una de las actividades que debe realizar el farmacéutico comunitario orientada hacia el paciente. Con el objetivo de conocer la influencia de la educación sanitaria en los pacientes, se realizó un estudio controlado en farmacias comunitarias de la provincia de Castellón. Material y métodos: En el estudio participaron catorce oficinas de farmacia (siete en el grupo control y siete en el grupo intervención). En todas ellas se realizó una encuesta inicial a los pacientes sobre educación para la salud. En las farmacias del grupo intervención se realizaron cinco campañas de educación sanitaria y al finalizar cada campaña los pacientes completaron una encuesta para valorar la educación sanitaria recibida. En las farmacias del grupo control se pasaron las encuestas a los pacientes pero no se realizaron las campañas de educación sanitaria. Resultados y discusión: Los pacientes están significativamente más satisfechos con la formación que reciben en las farmacias que realizan educación sanitaria. Además, se incrementa significativamente la percepción que tiene la población del farmacéutico en la oficina de farmacia como punto de referencia a la hora de ayudar a resolver sus problemas de salud. La educación sanitaria permite que los pacientes reciban formación completa acerca de temas de salud que les preocupan y les proporciona más capacidad para resolverlos por ellos mismos.Introduction: Health education is one of the roles of the community pharmacist.A controlled study of pharmacies in the Spanish province of Castellón was carried out with the aim of determining the influence of health education on the general public. Material and methods: Fourteen pharmacies took part in the study: seven in the group control and seven in the intervention group. An initial survey about health education was conducted among the patients of all fourteen pharmacies. In the pharmacies in the intervention group five campaigns of health education were instigated; after each campaign patients answered a survey to evaluate the health education received. In the pharmacies in the control group the same surveys were carried out without the implementation of any educational campaigns. Results and discussion: Patients of the pharmacies in the intervention group were significantly more satisfied with their level of knowledge about health matters than those in the control other group. In addition, the same patients had a significantly more satisfied with the formation they received in the pharmacies that implemented the educational campaigns. In addition, patients of the pharmacies in the intervention group had a significantly better perception of the pharmacist and of the pharmacy as a reference point with respect to resolving their health problems. Health education informs patients about aspects of health and endows them with the aptitude to make decisions related to their health problems

    Análisis de los factores de riesgo del cáncer de mama desde la farmacia comunitaria

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    Introducción: el cáncer de mama es la neoplasia maligna más frecuente entre las mujeres, y en España es la que produce mayor número de muertes al año. La detección precoz propicia tratamientos menos agresivos y mayores tasas de curación. El objetivo de este estudio es analizar los factores de riesgo de las mujeres que acudieron a las oficinas de farmacia participantes en el estudio: antecedentes familiares, edad y sexo, edad de concepción, enfermedad mamaria benigna, sobrepeso u obesidad, terapia hormonal (anticonceptivos orales o terapia hormonal sustitutiva), tabaco y alcohol. Material y métodos: En el estudio participaron cinco oficinas de farmacia de distintas provincias. Para el análisis de los factores de riesgo se entregó a las mujeres una breve encuesta que debían completar. Resultados y conclusiones: Tras analizar los factores de riesgo, se concluye que un 12% de las mujeres participantes tiene un riesgo elevado de padecer cáncer de mama. Desde la farmacia se puede informar a las mujeres sobre los factores de riesgo del cáncer de mama, con el fin de que apliquen las medidas necesarias para prevenir y/o detectar a tiempo esta enfermedad

    Benchmark low-mass objects in Moving Groups

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    This is an Open Access article distributed under the terms of the Creative Commons Attribution License 2.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.In order to compile a sample of ultracool dwarfs that will serve as benchmarks for testing theoretical formation and evolutionary models, we selected low-mass cool (>M7) objects that are potentially members of five known young Moving Groups in the solar neighbourhood. We have studied the kinematics of the sample, finding that 49 targets belong to the young disk area, from which 36 are kinematic member of one of the five moving groups under study. Some of the identified low-mass members have been spectroscopically characterised (T-eff, log g) and confirmed as young members through a detailed study of age indicators

    Análisis de los factores de riesgo del cáncer de mama desde la farmacia comunitaria

    Get PDF
    Introducción: el cáncer de mama es la neoplasia maligna más frecuente entre las mujeres, y en España es la que produce mayor número de muertes al año. La detección precoz propicia tratamientos menos agresivos y mayores tasas de curación. El objetivo de este estudio es analizar los factores de riesgo de las mujeres que acudieron a las oficinas de farmacia participantes en el estudio: antecedentes familiares, edad y sexo, edad de concepción, enfermedad mamaria benigna, sobrepeso u obesidad, terapia hormonal (anticonceptivos orales o terapia hormonal sustitutiva), tabaco y alcohol. Material y métodos: En el estudio participaron cinco oficinas de farmacia de distintas provincias. Para el análisis de los factores de riesgo se entregó a las mujeres una breve encuesta que debían completar. Resultados y conclusiones: Tras analizar los factores de riesgo, se concluye que un 12% de las mujeres participantes tiene un riesgo elevado de padecer cáncer de mama. Desde la farmacia se puede informar a las mujeres sobre los factores de riesgo del cáncer de mama, con el fin de que apliquen las medidas necesarias para prevenir y/o detectar a tiempo esta enfermedad
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