350 research outputs found

    Aloe Vera extract-based composite nanofibers for wound dressing applications

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    Natural, biocompatible, and biodegradable composite nanofibers made of Aloe vera extract, pullulan, chitosan, and citric acid were successfully produced via Forcespinning® technology. The addition of Aloe vera extract at different weight percent loadings was investigated. The morphology, thermal properties, physical properties, and water absorption of the nanofibers were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). The developed nanofiber membranes exhibited good water absorption capabilities, synergistic antibacterial activity against Escherichia coli, and promoted cell attachment and growth. Its porous and high surface area structure make it a potential candidate for wound dressing applications due to its ability to absorb excessive blood and exudates, as well as provide protection from infection while maintaining good thermal stability

    Functionalized Thermoplastic Polyurethane Nanofibers: An Innovative Triboelectric Energy Generator

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    A triboelectric nanogenerator (TENG) is one of the most significantly innovative microdevices for built-in energy harvesting with wearable and portable electronics. In this study, the forcespinning technology was used to synthesize a nanofiber (NF) mat-based TENG. Polyvinylidene fluoride (PVDF) membrane was used as the negative triboelectric electrode/pole, and chemically designed and functionalized thermoplastic polyurethane (TPU) was used as the positive electrode/pole for the TENG. The electronic interference, sensitivity, and gate voltage of the synthesized microdevices were investigated using chemically modified bridging of multi-walled carbon nanotubes (MWCNT) with a TPU polymer repeating unit and bare TPU-based positive electrodes. The chemical functionality of TPU NF was integrated during the NF preparation step. The morphological features and the chemical structure of the nanofibers were characterized using a field emission scanning electron microscope and Fourier-transform infrared spectroscopy. The electrical output of the fabricated MWCNT-TPU/PVDF TENG yielded a maximum of 212 V in open circuit and 70 µA in short circuit at 240 beats per minute, which proved to be 79% and 15% higher than the TPU/PDVF triboelectric nanogenerator with an electronic contact area of 3.8 × 3.8 cm2, which indicates that MWCNT enhanced the electron transportation facility, which results in significantly enhanced performance of the TENG. This device was further tested for its charging capacity and sensory performance by taking data from different body parts, e.g., the chest, arms, feet, hands, etc. These results show an impending prospect and versatility of the chemically functionalized materials for next-generation applications in sensing and everyday energy harvesting technology

    EVALUACIÓN COMPUTARIZADA DE PRUEBAS PSICOLÓGICAS MEDIANTE EL PROCESAMIENTO DIGITAL DE IMÁGENES

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    Este trabajo presenta un algoritmo desarrollado en MATLAB® para la evaluación computarizadade pruebas psicológicas realizadas con la técnica de lápiz-papel de opción múltiple. Con la utilización adecuada de las herramientas actuales para el procesamiento digital de imágenes y reconocimiento de patrones, es posible la evaluación automática de cualquier prueba psicológica realizada con la técnica de lápiz-papel utilizando una computadora personal convencional. En este caso, para demostrar el potencial del algoritmo, fue adaptado para la escala básica del Inventario Multifásico de la Personalidad de Minnesota para individuos masculinos. Los resultados obtenidos demuestran 99.5% de exactitud y la obtención de la gráfica del perfil en 40 segundos. Con el formato digitalizado de la hoja de respuestas, el algoritmo realiza el acondicionamiento de la imagen, la detección y clasificación de los ítems y la contabilidad de las respuestas; finalmente, brinda la gráfica del perfil del individuo

    Design and Validation of a Portable Handheld Device to Produce Fine Fibers Using Centrifugal Forces

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    In the present research project, a novel portable battery-powered handheld device able to produce micron and submicron fibers using centrifugal forces is proposed. The design includes spinnerets with a clamshell configuration with multiple chambers or reservoirs (2, 4, and 8) and different exit orifice diameters (400, 500, 600, and 800 µm). The rotational speed is controlled via an Arduino microcontroller. To validate the design, a series of experiments were conducted and the effect of the orifice diameter, number of chambers, and velocity on the resulting fibers’ diameter and yield was studied. For the experiments, a polymeric solution of Polyvinyl Alcohol (PVA) was prepared. The fiber yield was gravimetrically quantified, and the fiber morphology and diameter were analyzed by means of scanning electron microscopy (SEM). The experimental results showed that spinnerets with an orifice diameter of 500 microns yielded the greatest amount of fibers (0.0777 g). In addition, the number of chambers also affected the amount of fibers produced, and it was determined that the fiber diameter size is dependent on the spinneret speed. Fibers 80 nm in diameter were observed at 6500 rpm

    Influence of Mediterranean Diet Adherence and Physical Activity on Bone Health in Celiac Children on a Gluten-Free Diet

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    We aimed to assess the influence of the Mediterranean Diet adherence and physical activity (PA) on body composition, with a particular focus on bone health, in young patients with celiac disease (CD). The CD group (n = 59) included children with CD with a long (>18 months, n = 41) or recent (<18 months, n = 18) adherence to a gluten-free diet (GFD). The non-celiac group (n = 40) included non-celiac children. After adjusting for potential confounders, the CD group showed lower body weight (p = 0.034), lean mass (p = 0.003), bone mineral content (p = 0.006), and bone Z-score (p = 0.036) than non-celiac children, even when the model was further adjusted for adherence to a GFD for at least 18 months. Among CD children, spending greater time in vigorous physical activity was associated with higher lean mass (p = 0.020) and bone mineral density with evidence of statistical significance (p = 0.078) regardless of the time they followed a GFD. In addition, a greater Mediterranean Diet adherence was associated with a higher bone Z-score (p = 0.020). Moreover, lean mass was strongly associated with bone mineral density and independently explained 12% of its variability (p < 0.001). These findings suggest the importance of correctly monitoring lifestyle in children with CD regarding dietary habits and PA levels to improve lean mass and, consequently, bone quality in this population.Regional Government of Andalusia, Excellence Research Project No P12-AGR-2581Project from the University of Granada Ref. PP2017-PIP14Spanish Ministry of Education, Culture, and Sports (Grant number FPU17/03715

    Factores mercadológicos utilizados por las organizaciones de producción cinematográfica mexicanas (OPCM) y su impacto en los ingresos en taquilla:.

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    This document is intended to capture the marketing factors impact in the spectator purchase decisions of ticket at the box office in Monterrey and it metropolitan area, thereby increasing the income of the Mexican Motion Pictures Production Organizations (OPCM). Reference is made to the Mexican booming film industry of the 40´s generating economic and cultural wealth. We analyze the recent performance of Mexican and U.S. cinema referencing to the years from 2002 to 2007. We discuss some factors that can be used as supporting tools for marketing by de OPCM in their productions, such as special effects, enhancing the club effect, merchandising, genre and film classification, as well as the release date. We study in detail the marketing main factors used by the OPCM: advertising, critics, talent, recommendations and availability in theaters; and through the application of a poll and a linear regression analysis, we determine the impact of these on box office revenues

    Las comunidades terapéuticas como tratamiento para las drogodependencias: una revisión sistemática del seguimiento a corto plazo

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    Objetivo. Las comunidades terapéuticas (CT) constituyen uno de los tratamientos más extensos para las drogodependencias; sin embargo, su investigación es escasa. El objetivo fue realizar una revisión sistemática para conocer los elementos metodológicos de los estudios de seguimiento a corto plazo y, a su vez, describir las consecuencias de las CT. Material y método. Se aplicó el "Preferred Reporting Items for Systematic reviews and meta- Analyses" (PRISMA) para la búsqueda en Medline, PsycINFO, PsycARTICLES y PsycCRITIQUES de estudios de seguimiento a corto plazo de CT entre 1980 y 2010. Resultados. El seguimiento consiste en un registro inicial y, al menos, otro al medio año de tratamiento; la muestra mínima contiene 60 usuarios con una mayor prevalencia de hombres solteros;el 50% continúa en seguimiento y/o alcanza la abstinencia. Conclusión. Las CT parecen ser beneficiosas para el ajuste del consumo y otros aspectos psicosociales, aunque la falta de información dificulta garantizar la comparación de estos hallazgos. © 2013 Elsevier España, S.L. y SET. Todos los derechos reservados

    Relationship between body appreciation, intuitive eating and gratitude: A review

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    En este estudio se realizó una revisión de la literatura para examinar el aprecio corporal con relación a la alimentación intuitiva y la gratitud en mujeres y hombres, adolescentes y adultos. Los artículos se identificaron a través de PubMed, ProQuest Central, EBSCO y Web of Science. Treinta y un estudios transversales y uno longitudinal cumplieron con los criterios de elegibilidad y mayormente se realizaron en Norteamérica. La relación entre gratitud, aprecio corporal y alimentación intuitiva fue positiva y significativa tanto en hombres como en mujeres, adolescentes y adultos. Además, la gratitud predice el aprecio corporal, el cual a su vez media la relación entre gratitud y alimentación intuitiva, en mujeres. Este estudio aportó información valiosa sobre la importancia de la actitud agradecida para desarrollar y/o mantener una imagen corporal positiva y hábitos alimentarios adaptativos. Este hallazgo es importante, debido a que la gratitud puede ser modificada por medio de intervenciones terapéuticas.El primer autor recibió apoyo financiero del Consejo Nacional de Ciencia y Tecnología (CONACyT), beca 80853
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