26 research outputs found

    Behaviour of piozoelectric devices embedded in bone cement

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    Bone cements based on polymethacrylate (PMMA) are essential products in joint arthroplasty. PMMA bone cement function is to locate the implants components in the body skeleton, load transition through the joint into the bone and muscle surrounding for a very for a very long period of time. Its mechanical properties are well established in the literature. Since bone cement fills the void between the prosthesis (polymer or metallic) and bone, it is subjected to high stress and has to operate in a relatively aggressive environment, like human body. Therefore, based on surrounding environment PMMA bone cements application, this material has specific mechanical properties that enhance a good performance in this condition. These stresses are mainly measured indirectly with non-invasive methods. In-situ measurements would be more interesting to really understand and quantify these stresses. Piezoelectric devices are an interesting way to measure forces in difficult accessibility environment, since they are self-power, i. e., they are able to generate an electric signal by converting mechanical energy into electrics with no need for power supply. When embedded in bone cement one expects to be able to analyze the health structure in real-time. Positioning of the sensing device is a critical factor worthy of a thorough study in order to understand its behavior to surroundings

    The Psychological Science Accelerator’s COVID-19 rapid-response dataset

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    In response to the COVID-19 pandemic, the Psychological Science Accelerator coordinated three large-scale psychological studies to examine the effects of loss-gain framing, cognitive reappraisals, and autonomy framing manipulations on behavioral intentions and affective measures. The data collected (April to October 2020) included specific measures for each experimental study, a general questionnaire examining health prevention behaviors and COVID-19 experience, geographical and cultural context characterization, and demographic information for each participant. Each participant started the study with the same general questions and then was randomized to complete either one longer experiment or two shorter experiments. Data were provided by 73,223 participants with varying completion rates. Participants completed the survey from 111 geopolitical regions in 44 unique languages/dialects. The anonymized dataset described here is provided in both raw and processed formats to facilitate re-use and further analyses. The dataset offers secondary analytic opportunities to explore coping, framing, and self-determination across a diverse, global sample obtained at the onset of the COVID-19 pandemic, which can be merged with other time-sampled or geographic data

    The Psychological Science Accelerator’s COVID-19 rapid-response dataset

    Get PDF
    In response to the COVID-19 pandemic, the Psychological Science Accelerator coordinated three large-scale psychological studies to examine the effects of loss-gain framing, cognitive reappraisals, and autonomy framing manipulations on behavioral intentions and affective measures. The data collected (April to October 2020) included specific measures for each experimental study, a general questionnaire examining health prevention behaviors and COVID-19 experience, geographical and cultural context characterization, and demographic information for each participant. Each participant started the study with the same general questions and then was randomized to complete either one longer experiment or two shorter experiments. Data were provided by 73,223 participants with varying completion rates. Participants completed the survey from 111 geopolitical regions in 44 unique languages/dialects. The anonymized dataset described here is provided in both raw and processed formats to facilitate re-use and further analyses. The dataset offers secondary analytic opportunities to explore coping, framing, and self-determination across a diverse, global sample obtained at the onset of the COVID-19 pandemic, which can be merged with other time-sampled or geographic data

    A global experiment on motivating social distancing during the COVID-19 pandemic

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    Finding communication strategies that effectively motivate social distancing continues to be a global public health priority during the COVID-19 pandemic. This cross-country, preregistered experiment (n = 25,718 from 89 countries) tested hypotheses concerning generalizable positive and negative outcomes of social distancing messages that promoted personal agency and reflective choices (i.e., an autonomy-supportive message) or were restrictive and shaming (i.e. a controlling message) compared to no message at all. Results partially supported experimental hypotheses in that the controlling message increased controlled motivation (a poorly-internalized form of motivation relying on shame, guilt, and fear of social consequences) relative to no message. On the other hand, the autonomy-supportive message lowered feelings of defiance compared to the controlling message, but the controlling message did not differ from receiving no message at all. Unexpectedly, messages did not influence autonomous motivation (a highly-internalized form of motivation relying on one’s core values) or behavioral intentions. Results supported hypothesized associations between people’s existing autonomous and controlled motivations and self-reported behavioral intentions to engage in social distancing: Controlled motivation was associated with more defiance and less long-term behavioral intentions to engage in social distancing, whereas autonomous motivation was associated with less defiance and more short- and long-term intentions to social distance. Overall, this work highlights the potential harm of using shaming and pressuring language in public health communication, with implications for the current and future global health challenges

    Synthesis and characterization of copolymers of styrene and N-methylolacrylamide

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    Copolymers of styrene (ST) and N-methylolacrylamide (NMA) were synthesized by emulsion polymerization for different initial weight ratios of ST/NMA. Fast reaction rates and high conversions are achieved regardless of the ST/NMA ratio. NMA content in copolymers, as deduced by DSC, FTIR and Kjeldhal analysis, is higher as the initial ST/NMA ratio decreases. Glass transition temperature of copolymers increases as the ST/NMA ratio decreases and it decreases with reaction time for a fixed ST/NMA ratio. The latter results and FTIR spectra as well as Kjeldhal analysis as a function of reaction time indicate that NMA reacts initially in the aqueous phase, after which ST, because of its overall larger concentration, is incorporated preferentially in the polymer. © 1993 Springer-Verlag

    Data-driven control of LVDC network converters: Active load stabilization

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    This paper addresses the (model-free) data-driven control of power converters, acting as distributed generators, in low voltage direct current (LVDC) networks (e.g. DC microgrids, DC distributed power systems, DC buses wit multiple sources and loads, etc.). Since traditional stand-alone control design, cannot guarantee stability when converters are connected to a network, it is proposed a deterministic solution that does not require the network model– an approach purely based on measurement data. This is a suitable way to overcome common issues when using a model-based approach, e.g. the use of an excessive number of variables and equations, the presence of un-modeled dynamics, unknown parameters and/or the lack of first principle model equations. To corroborate the advantages of the proposed approach, the present work addresses an extreme but also realistic scenario: weak networks with active loads, such as constant power loads (CPLs). It is also shown that the proposed scheme guarantees stability in a rigorous deterministic way– using a Lyapunov approach based on coefficient matrices directly constructed from data. Simulation results using a multi- bus LVDC distribution network, based on PSCAD/EMTDC, are provided as proof of concept

    Mexican consensus on lysosomal acid lipase deficiency diagnosis

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    Introduction: Lysosomal acid lipase deficiency (LAL-D) causes progressive cholesteryl ester and triglyceride accumulation in the lysosomes of hepatocytes and monocyte-macrophage system cells, resulting in a systemic disease with various manifestations that may go unnoticed. It is indispensable to recognize the deficiency, which can present in patients at any age, so that specific treatment can be given. The aim of the present review was to offer a guide for physicians in understanding the fundamental diagnostic aspects of LAL-D, to successfully aid in its identification. Methods: The review was designed by a group of Mexican experts and is presented as an orienting algorithm for the pediatrician, internist, gastroenterologist, endocrinologist, geneticist, pathologist, radiologist, and other specialists that could come across this disease in their patients. An up-to-date review of the literature in relation to the clinical manifestations of LAL-D and its diagnosis was performed. The statements were formulated based on said review and were then voted upon. The structured quantitative method employed for reaching consensus was the nominal group technique. Results: A practical algorithm of the diagnostic process in LAL-D patients was proposed, based on clinical and laboratory data indicative of the disease and in accordance with the consensus established for each recommendation. Conclusion: The algorithm provides a sequence of clinical actions from different studies for optimizing the diagnostic process of patients suspected of having LAL-D

    Consenso mexicano sobre el diagnóstico de la deficiencia de lipasa ácida lisosomal

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    Introducción: La deficiencia de lipasa ácida lisosomal (DLAL) ocasiona el almacenamiento de ésteres de colesterol y triglicéridos en los lisosomas de los hepatocitos y células del sistema monocito-macrófago y, como consecuencia, produce una enfermedad sistémica con manifestaciones variadas que puede pasar inadvertida; es indispensable reconocerla ya que puede diagnosticarse a cualquier edad y recibir tratamiento específico. El objetivo de este documento es ofrecer una guía que permita al médico conocer los aspectos fundamentales relacionados con el diagnóstico de la DLAL para garantizar su identificación. Este documento fue diseñado por un grupo de expertos y se presenta como un algoritmo para orientar al médico pediatra, internista, gastroenterólogo, endocrinólogo, genetista, patólogo, imagenólogo y otros especialistas que pudieran enfrentar a esta entidad. Métodos: Se realizó una revisión actualizada de la literatura con respecto a las manifestaciones clínicas y el diagnóstico de la DLAL por parte de los expertos mexicanos. Se plantearon las declaraciones con base en esta revisión y se sometieron a votación. Se utilizó el método cuantitativo estructurado de técnica de grupo nominal para alcanzar un consenso. Resultado: Se propone un algoritmo práctico del proceso diagnóstico de pacientes con DLAL, con base en datos clínicos y de laboratorio indicativos de la enfermedad, acorde con el consenso estabilizador para cada recomendación. Conclusión: Este algoritmo proporciona una secuencia de acciones clínicas, basado en las manifestaciones clínicas obtenidas de los diferentes estudios, con el propósito de optimizar el proceso diagnóstico de los pacientes con sospecha de DLAL
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