Nanocomposites with shape memory behavior based on a segmented polyurethane and magnetic nanostructures

Shape-memory composites based on a commercial segmented polyurethane and magnetite (Fe⁠3O⁠4) nanoparticles(NPs) were prepared by a simple suspension casting method. The properties of the resulting nanocomposites,containing 1 to 10 nominal wt.% magnetic particles, were evaluated by thermogravimetric tests, contact anglemeasurements, differential scanning calorimetry, infrared and X-ray spectroscopy, static and thermal cyclic tensiletests, dynamic mechanical analysis and experiments of alternating-magnetic-field heating. It was found thatmost of the suspended NPs could be successfully incorporated into the polyurethane matrix, and thus compositesamples with up to 7 wt.% actual concentration were obtained. On the other hand, the incorporation of magnetitenanoparticles to the shape memory polyurethane did not significantly affect most of the matrix properties,including its shape memory behavior, while added magnetic response to the nanocomposites. Thus, nanocompositeswere able to increase their temperature when exposed to an alternating magnetic field, which allowedthem to recover their original shape quickly by an indirect triggering method.Fil: Soto, Guillermo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Meiorin, Cintia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Actis, Daniel Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Mendoza Zélis, Pedro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Mosiewicki, Mirna Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Marcovich, Norma Esther. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin

Goat-rearing and local development : analysis and evaluation of two case studies from central Argentina

Enfocado como un estudio de caso, el artículo analiza dos iniciativas agroindustriales que se proponen brindar una solución «local» a la crisis que enfrenta la producción caprina en Argentina central: i) el «Proyecto de Leche Caprina» encabezado por la Cooperativa de Productores Capricultores del Valle de Punilla que planea desarrollar una cuenca láctea; y ii) el «Proyecto del Ente Caprino» liderado por la Municipalidad de Quilino que propone instalar un frigorífico para el faenamiento de ganado caprino. Si bien ambos proyectos comparten la idea de promover el desarrollo regional a través del fomento de la capricultura, poseen características muy diferentes en cuanto al sistema de actores presentes y la estrategia que implementan para alcanzar los objetivos propuestos. Ambas experiencias fueron estudiadas considerando las mismas dimensiones: origen de la iniciativa, trayectoria del proyecto y del sistema de actores presentes, y evaluación de la experiencia en relación con los objetivos propuestos. El acompañamiento sistemático de cada uno de los proyectos permitió comprender la lógica subyacente en cada uno de ellos y las principales fortalezas y debilidades que los caracterizan. Finalmente, se analizaron las causas que explican la escasa relación que existe entre proyectos que en teoría deberían estar estrechamente vinculados y se formularon algunas reflexiones que permiten adelantar la posible trayectoria de cada uno de ellos.Using a case-study perspective, the paper analyses two agroindustrial initiatives aiming at finding a «local» solution to the crisis faced by goat-rearing production in Central Argentina: i) the «Goat Milk Project» led by the Cooperative of Got Farmers of Punilla, that seeks to develop a network for milk collection; and ii) the «Goat Farming Regulation Agency» which proposes to set up a slaughterhouse for goats. Even though both projects aim to promote regional development fostering goat rearing, they are very different since they draw upon different stakeholders networks, and have devised different strategies to reach their aims. Both experiences were studied considering the same analytical dimensions: origin of the initiative, trajectory of the project and of the stakeholders' network, and evaluation of the experiences considering their objectives. A systematic follow up of each case study allowed to understand their underpinning logics and their strengths and weakness. Finally, the causes explaining the scarce relationship between projects that should be closely linked are analysed, and some predictions are made about their possible trajectory.Fil: Ferrer, Guillermo.Fil: Silvetti, Felicitas.Fil: Cáceres, Daniel.Fil: Soto, Gustavo

Nanocomposites with shape memory behavior based on a segmented polyurethane and magnetic nanostructures

Shape-memory composites based on a commercial segmented polyurethane and magnetite (Fe⁠3O⁠4) nanoparticles(NPs) were prepared by a simple suspension casting method. The properties of the resulting nanocomposites,containing 1 to 10 nominal wt.% magnetic particles, were evaluated by thermogravimetric tests, contact anglemeasurements, differential scanning calorimetry, infrared and X-ray spectroscopy, static and thermal cyclic tensiletests, dynamic mechanical analysis and experiments of alternating-magnetic-field heating. It was found thatmost of the suspended NPs could be successfully incorporated into the polyurethane matrix, and thus compositesamples with up to 7 wt.% actual concentration were obtained. On the other hand, the incorporation of magnetitenanoparticles to the shape memory polyurethane did not significantly affect most of the matrix properties,including its shape memory behavior, while added magnetic response to the nanocomposites. Thus, nanocompositeswere able to increase their temperature when exposed to an alternating magnetic field, which allowedthem to recover their original shape quickly by an indirect triggering method.Instituto de Física La Plat

Magnetic nanocomposites based on shape memory polyurethanes

Shape memory composites based on a commercial segmented polyurethane and magnetite (Fe3O4) nanoparticles (MNPs) were prepared by a simple suspension casting method. The average sizes of individual magnetic particles/clusters were determined by TEM microscopy and corroborated from SAXS patterns. The magnetization properties of selected samples were evaluated using zero field cooling/field cooling (ZFC/FC) measurements and magnetization loops obtained at different temperatures. The results showed that magnetization at high field (20 k Oe) and coercitivity measured at 5 K increase with magnetite content and that all the composite films exhibit superparamagnetic behavior at 300 K. The specific absorption rate (SAR) of the nanocomposites was calculated by experimentally determining both the specific heat capacity and the heating rate of the films exposed to an alternant magnetic field. All nanocomposites were able to increase their temperature when exposed to an alternant magnetic field, although the final temperature reached resulted dependent of the MNPs concentration. What is more, a fast and almost complete recovery of the original shape of the nanocomposites containing more than 3 nominal wt.% MNP was obtained by this remote activation applied to the previously deformed samples.Instituto de Física La Plat

Magnetic nanocomposites based on shape memory polyurethanes

Shape memory composites based on a commercial segmented polyurethane and magnetite (Fe3O4) nanoparticles (MNPs) were prepared by a simple suspension casting method. The average sizes of individual magnetic particles/clusters were determined by TEM microscopy and corroborated from SAXS patterns. The magnetization properties of selected samples were evaluated using zero field cooling/field cooling (ZFC/FC) measurements and magnetization loops obtained at different temperatures. The results showed that magnetization at high field (20 k Oe) and coercitivity measured at 5 K increase with magnetite content and that all the composite films exhibit superparamagnetic behavior at 300 K. The specific absorption rate (SAR) of the nanocomposites was calculated by experimentally determining both the specific heat capacity and the heating rate of the films exposed to an alternant magnetic field. All nanocomposites were able to increase their temperature when exposed to an alternant magnetic field, although the final temperature reached resulted dependent of the MNPs concentration. What is more, a fast and almost complete recovery of the original shape of the nanocomposites containing more than 3 nominal wt.% MNP was obtained by this remote activation applied to the previously deformed samples.Instituto de Física La Plat

TRIBUNAL ARBITRAL DE INDUSTRIA COLOMBIANA DE MOTOCICLETAS YAMAHA S.A. (INCOLMOTOS YAMAHA S.A.) VS. OESIA COLOMBIA S.A.

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Efecto del Edentulismo en variables socio-psicológicas y físicas en adultos: revisión narrativa

32 p.El edentulismo corresponde a la pérdida parcial o total de dientes permanentes y es considerado un proceso irreversible, discapacitante y un problema de salud pública. Además, podría ser considerado un marcador del estado de la salud sistémica a nivel físico y/o psicológico. Esta revisión analizo el edentulismo en relación a las secuelas que podría provocar sobre una serie de variables asociadas a la salud física, social y psicológica en la adultez. Es por ello, que el objetivo de esta revisión es describir los efectos que genera la pérdida dentaria en el bienestar y salud general de los individuos, utilizando un enfoque integral y multidisciplinario al problema en estudio. La presente revisión de la literatura encontró una asociación entre el edentulismo y las variables dependientes socio-psicológicas estudiadas, para lo cual la perdida dentaria sería un co-factor relevante que potencia el desarrollo de estas condiciones. Por otra parte, en la mayoría de las variables físicas que son de carácter objetivo, se estableció una relación de causalidad. Por lo tanto, la perdida dentaria va a generar fuertes repercusiones en la salud general de las personas, siendo de suma importancia velar por mantener el mayor tiempo posible los dientes en boca, reforzando los programas de promoción, prevención y recuperación de la salud oral, como también el tratamiento odontológico no invasivo o mínimamente invasivo con tal de preservar este capital biológico bucodental durante el ciclo vital de las personas. // ABSTRACT: Edentulism corresponds to the partial or total loss of permanent teeth and is considered an irreversible, disabling process and a public health problem. In addition, it could be considered a marker of systemic health state at a physical and/or psychological level. This review analyzed edentulism in relation to the sequelae that it could cause on a series of variables associated with physical, social, and psychological health in adulthood. Thus, the objective of this review is to describe the effects that tooth loss generates on the wellbeing and general health of individuals, using a comprehensive and multidisciplinary approach to the problem under study. The present literature review found an association between edentulism and the sociopsychological dependent variables under study, for which tooth loss would be a relevant cofactor that enhances the development of these conditions. On the other hand, in most of the physical variables that are objective, a causal relationship was established. Therefore, tooth loss will generate strong repercussions on people's general health, being of utmost importance to ensure that teeth are kept in the mouth for as long as possible, reinforcing programs for the promotion, prevention, and recovery of oral health, as well as noninvasive or minimally invasive dental treatment in order to preserve this oral biological capital during the life cycle of people

Una experiencia de formación de maestros investigadores de ciencias naturales y educación ambiental: El semillero PiEnCias

This report presents Semillero PiEnCias experiences of the Education Faculty – Universidad de Antioquia, as a training strategy in educational research of teachers in the area of natural sciences and environmental education. The research incubator was created in July 2015 and to date has three cohorts of participants, mostly students and graduates of the area of natural sciences, but recently have involved students of mathematics and physics, children’s pedagogy and social sciences. One of the strategies that is privileged is the design of small projects, favoring teamwork and learning to do research through the design and development of the same project. The text synthesizes some of the learning and challenges of the research incubator, as a contribution to the reflection on the integral formation required by the teachersSe presenta en esta comunicación la experiencia del Semillero PiEnCias, de la Facultad de Educación – Universidad de Antioquia, como una estrategia de formación en investigación educativa de maestros del área de ciencias naturales y educación ambiental. El Semillero se creó en julio del 2015 y a la fecha tiene tres cohortes de participantes, en su mayoría estudiantes y egresados del área de ciencias naturales, pero más recientemente se han involucrado estudiantes de matemática y física, pedagogía infantil y ciencias sociales. Una de las estrategias que se privilegia es el diseño de proyectos, los cuales favorecen el trabajo en equipo a través del diseño y desarrollo del mismo. En el texto, se sintetizan algunas de los aprendizajes y retos que tiene el Semillero, como aporte a la reflexión sobre la formación integral que requieren los/as maestros/as

Property control and its effect on the management of movable property of a government institution, 2020

El presente estudio tuvo como finalidad determinar el efecto del control patrimonial en la administración de bienes muebles de la institución gubernamental en estudio en el 2020, para ello se realizó un estudio cuantitativo de tipo aplicada no experimental-transversal y alcance explicativo. La muestra estuvo conformada por 35 trabajadores quienes fueron sometidos un cuestionario, que fue el método de recolección de datos. Encontrando que el control patrimonial tiene un nivel regular-bueno la ser evaluado por los encuestados con un 48.6% y que la administración de bienes obtuvo un nivel medio con un 68.6%, además se halló que el nivel de relación con Pearson (Sig<0.05) con un 0.01 y de efecto con la prueba Eta (valores cercanos a 1) con un 0.887 y 0.855. Concluyendo que control patrimonial tiene un efecto significativo en la administración de bienes muebles dentro de la institución gubernamentalThe purpose of this study was to determine the effect of patrimonial control on the administration of personal property of the governmental institution under study in 2020, for which purpose a quantitative study of a non-experimental-transversal applied type and explanatory scope was carried out. The sample consisted of 35 workers who were submitted to a questionnaire, which was the data collection method. It was found that patrimonial control has a regular-good level to be evaluated by the respondents with 48.6% and that asset management obtained a medium level with 68.6%, in addition it was found that the level of relationship with Pearson (Sig<0.05) with 0.01 and of effect with the Eta test (values close to 1) with 0.887 and 0.855. It was concluded that patrimonial control has a significant effect on the administration of personal property within the governmental institutio

In vitro Characterization of Anti-SARS-CoV-2 Intravenous Immunoglobulins (IVIg) Produced From Plasma of Donors Immunized With the BNT162b2 Vaccine and Its Comparison With a Similar Formulation Produced From Plasma of COVID-19 Convalescent Donors

Despite vaccines are the main strategy to control the ongoing global COVID-19 pandemic, their effectiveness could not be enough for individuals with immunosuppression. In these cases, as well as in patients with moderate/severe COVID-19, passive immunization with anti-SARS-CoV-2 immunoglobulins could be a therapeutic alternative. We used caprylic acid precipitation to prepare a pilot-scale batch of anti-SARS-CoV-2 intravenous immunoglobulins (IVIg) from plasma of donors immunized with the BNT162b2 (Pfizer-BioNTech) anti-COVID-19 vaccine (VP-IVIg) and compared their in vitro efficacy and safety with those of a similar formulation produced from plasma of COVID-19 convalescent donors (CP-IVIg). Both formulations showed immunological, physicochemical, biochemical, and microbiological characteristics that meet the specifications of IVIg formulations. Moreover, the concentration of anti-RBD and ACE2-RBD neutralizing antibodies was higher in VP-IVIg than in CP-IVIg. In concordance, plaque reduction neutralization tests showed inhibitory concentrations of 0.03–0.09 g/L in VP-IVIg and of 0.06–0.13 in CP-IVIg. Thus, VP-IVIg has in vitro efficacy and safety profiles that justify their evaluation as therapeutic alternative for Rojas-Jiménez et al. Anti-SARS-CoV-2 IVIg clinical cases of COVID-19. Precipitation with caprylic acid could be a simple, feasible, and affordable alternative to produce formulations of anti-SARS-CoV-2 IVIg to be used therapeutically or prophylactically to confront the COVID-19 pandemic in middle and low-income countries.Universidad de Costa Rica/[741-C0-198]/UCR/Costa RicaBanco Centroamericano de Integración Económica/[DI- 87/2020]/BCIE/Costa RicaMinisterio de Ciencia, Innovación, Tecnología y Telecomunicaciones de Costa Rica/[FV-0001- 20]/MICITT/Costa RicaGerman academic exchange services/[57592642]/DAAD/AlemaniaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto Clodomiro Picado (ICP)UCR::Vicerrectoría de Docencia::Salud::Facultad de MicrobiologíaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Centro de Investigación en Enfermedades Tropicales (CIET