179 research outputs found

    Analysis of the interaction of vinyl and carbonyl silanes with carbon nanofiber surfaces

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    Carbon nanofibers (CNFs) have been treated with vinyltryethoxy silane (VTS) and 3-metacryloxypropyltrimethoxy silane (MPS). CNF–silane interactions have been analyzed by means of TGA, FTIR-ATR, TEM, HRTEM, SEM and nitrogen adsorption. For similar silane concentration solutions TG analysis has shown that VTS and MPS form one and three silane monolayers, respectively. This has also been corroborated by the presence of an FTIR-ATR band at 1250 cm−1 assigned to Si–O–Si bonds of silica layers. For low silane concentrations, the vinyl group of VTS is bonded to the graphene CNF surface mainly through π–π interactions. However, MPS interacts through the carbonyl group with hydroxyl groups of graphene defect sheets existing probably in micropores. Silanol–CNF hydroxyl interactions are also expected at these silane concentrations. For high silane concentration, when the silica layer is formed, both silanes present vinyl free and carbonyl free groups, as observed by the 1370 and 1686 cm−1 FTIR-ATR bands, respectively. Nitrogen adsorption has shown that while VTS is adsorbed mainly on the defect free graphene surface, MPS is adsorbed on the micropores and, therefore on the hydroxyl defect graphene sites. These results are finally correlated with the dispersion stability of both silanes on water and styrene solutions

    Dynamic growth pattern of chinchilla (<i>Chinchilla lanigera</i>) kits during lactation

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    Se evaluó la aptitud de la función lineal y de la función exponencial creciente para describir el comportamiento dinámico del peso corporal de gazapos de chinchilla durante la lactancia. Los valores observados de las variancias residuales y de los coeficientes de determinación asignaron una leve ventaja al modelo lineal. La función lineal subestimó el peso al nacimiento mientras que la función exponencial lo sobreestimó sin diferenciarse en la magnitud de las diferencias de uno u otro signo entre los valores estimados y observados. La utilización del modelo lineal para caracterizar el crecimiento de gazapos machos proveniente de camadas con uno, dos o tres crías, entre el nacimiento y el destete a los 43 días de edad, permitió constatar que el aumento del tamaño de la camada de uno a dos gazapos, si bien disminuye ligeramente el peso inicial y la tasa de crecimiento predestete, no presenta un efecto detrimental de trascendencia sobre el crecimiento en dicha etapa. Por el contrario, la presencia de un tercer gazapo reduce de manera notoria tanto el peso inicial de los miembros de la camada como su aumento medio diario de peso hasta el destete. De acuerdo con lo relevado en este estudio resultaría más conveniente plantear como objetivo aumentar el número de pariciones por año, por ejemplo mediante un manejo adecuado del fotoperíodo, que aumentar el tamaño de la camada al parto por encima de dos gazapos.The ability of linear and exponential functions to describe the dynamic behavior of body weight of chinchilla kits during lactation was evaluated. Residual variance and coefficient of determination average values derived from each model assigned to linear function a slight advantage. While the linear function underestimated birth weight the exponential model overestimated it showing both models differences of similar magnitude between estimated and observed values. The use of the linear model to characterize the dynamic growth of male kits belonging to litters with one, two or three pups, between birth and weaning at 43 days of age, allowed to confirm that increasing litter size from one to two pups slightly decreases their initial body weight and their growth rate during lactation, without a detrimental effect on overall pre-weaning growth. By contrast, the presence of a third kit in the litter markedly reduces both initial body weight and daily body weight gain from birth to weaning. According to data surveyed in this study increasing the number of parturitions per female per year, for example through an appropriate management of photoperiod, would be more useful than increasing litter size at birth above two kits to increase the overall efficiency of the system.Facultad de Ciencias Veterinaria

    Dynamic growth pattern of chinchilla (<i>Chinchilla lanigera</i>) kits during lactation

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    Se evaluó la aptitud de la función lineal y de la función exponencial creciente para describir el comportamiento dinámico del peso corporal de gazapos de chinchilla durante la lactancia. Los valores observados de las variancias residuales y de los coeficientes de determinación asignaron una leve ventaja al modelo lineal. La función lineal subestimó el peso al nacimiento mientras que la función exponencial lo sobreestimó sin diferenciarse en la magnitud de las diferencias de uno u otro signo entre los valores estimados y observados. La utilización del modelo lineal para caracterizar el crecimiento de gazapos machos proveniente de camadas con uno, dos o tres crías, entre el nacimiento y el destete a los 43 días de edad, permitió constatar que el aumento del tamaño de la camada de uno a dos gazapos, si bien disminuye ligeramente el peso inicial y la tasa de crecimiento predestete, no presenta un efecto detrimental de trascendencia sobre el crecimiento en dicha etapa. Por el contrario, la presencia de un tercer gazapo reduce de manera notoria tanto el peso inicial de los miembros de la camada como su aumento medio diario de peso hasta el destete. De acuerdo con lo relevado en este estudio resultaría más conveniente plantear como objetivo aumentar el número de pariciones por año, por ejemplo mediante un manejo adecuado del fotoperíodo, que aumentar el tamaño de la camada al parto por encima de dos gazapos.The ability of linear and exponential functions to describe the dynamic behavior of body weight of chinchilla kits during lactation was evaluated. Residual variance and coefficient of determination average values derived from each model assigned to linear function a slight advantage. While the linear function underestimated birth weight the exponential model overestimated it showing both models differences of similar magnitude between estimated and observed values. The use of the linear model to characterize the dynamic growth of male kits belonging to litters with one, two or three pups, between birth and weaning at 43 days of age, allowed to confirm that increasing litter size from one to two pups slightly decreases their initial body weight and their growth rate during lactation, without a detrimental effect on overall pre-weaning growth. By contrast, the presence of a third kit in the litter markedly reduces both initial body weight and daily body weight gain from birth to weaning. According to data surveyed in this study increasing the number of parturitions per female per year, for example through an appropriate management of photoperiod, would be more useful than increasing litter size at birth above two kits to increase the overall efficiency of the system.Facultad de Ciencias Veterinaria

    Dynamic growth pattern of chinchilla (<i>Chinchilla lanigera</i>) kits during lactation

    Get PDF
    Se evaluó la aptitud de la función lineal y de la función exponencial creciente para describir el comportamiento dinámico del peso corporal de gazapos de chinchilla durante la lactancia. Los valores observados de las variancias residuales y de los coeficientes de determinación asignaron una leve ventaja al modelo lineal. La función lineal subestimó el peso al nacimiento mientras que la función exponencial lo sobreestimó sin diferenciarse en la magnitud de las diferencias de uno u otro signo entre los valores estimados y observados. La utilización del modelo lineal para caracterizar el crecimiento de gazapos machos proveniente de camadas con uno, dos o tres crías, entre el nacimiento y el destete a los 43 días de edad, permitió constatar que el aumento del tamaño de la camada de uno a dos gazapos, si bien disminuye ligeramente el peso inicial y la tasa de crecimiento predestete, no presenta un efecto detrimental de trascendencia sobre el crecimiento en dicha etapa. Por el contrario, la presencia de un tercer gazapo reduce de manera notoria tanto el peso inicial de los miembros de la camada como su aumento medio diario de peso hasta el destete. De acuerdo con lo relevado en este estudio resultaría más conveniente plantear como objetivo aumentar el número de pariciones por año, por ejemplo mediante un manejo adecuado del fotoperíodo, que aumentar el tamaño de la camada al parto por encima de dos gazapos.The ability of linear and exponential functions to describe the dynamic behavior of body weight of chinchilla kits during lactation was evaluated. Residual variance and coefficient of determination average values derived from each model assigned to linear function a slight advantage. While the linear function underestimated birth weight the exponential model overestimated it showing both models differences of similar magnitude between estimated and observed values. The use of the linear model to characterize the dynamic growth of male kits belonging to litters with one, two or three pups, between birth and weaning at 43 days of age, allowed to confirm that increasing litter size from one to two pups slightly decreases their initial body weight and their growth rate during lactation, without a detrimental effect on overall pre-weaning growth. By contrast, the presence of a third kit in the litter markedly reduces both initial body weight and daily body weight gain from birth to weaning. According to data surveyed in this study increasing the number of parturitions per female per year, for example through an appropriate management of photoperiod, would be more useful than increasing litter size at birth above two kits to increase the overall efficiency of the system.Facultad de Ciencias Veterinaria

    Encuesta sobre los Usos Guías de Clase como aproximación a los REA. Una aproximación a través de la investigacción-acción

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    [ES]En este artículo se presentan los resultados de una encuesta sobre prácticas docentes y conocimiento de Recursos Educativos Abiertos (REA). La encuesta se formula en base a la consideración de la activad docente en base a fases de investigación acción. En este sentido se pregunta a los docentes sobre sus prácticas en la preparación de guías de clases antes de las mismas, la documentación con evidencias de lo que pasa durante las clases y los cambios que se producen en las mismas, y la reflexión posterior una vez concluyen las clases. También se incluyen preguntas sobre el conocimiento y el posicionamiento ante los REA La encuesta se dirigió a profesorado de primaria y secundaria de Galicia y del Norte de Portugal. En total se obtuvieron 602 respuestas de las que se realizan una serie de reflexiones de cara al desarrollo de los REA

    Protective Effect of Quercetin Treatment on Gut Microbiota Imbalance in Obesity-Associated NAFLD in Patients and in HFD-FED Mice

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    2 p.Gut microbiota is involved in obesity, metabolic syndrome and nonalcoholic fatty liver disease (NAFLD). Quercetin may modulate the intestinal microbiota composition, suggesting therapeutic potential in NAFLD. The present study aims to establish the role of gut microbiota imbalance in obesity-related NAFLD development in patients and in an in vivo model and to investigate benefits of experimental treatment with quercetin. Resumen de un trabajo resultado del proyecto de investigación financiado por la Consejería de Educación de la Junta de Castilla y León (referencia LE063U16)S

    Evaluation of Natural Language Processing for the Identification of Crohn Disease-Related Variables in Spanish Electronic Health Records:A Validation Study for the PREMONITION-CD Project

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    Background: The exploration of clinically relevant information in the free text of electronic health records (EHRs) holds the potential to positively impact clinical practice as well as knowledge regarding Crohn disease (CD), an inflammatory bowel disease that may affect any segment of the gastrointestinal tract. The EHRead technology, a clinical natural language processing (cNLP) system, was designed to detect and extract clinical information from narratives in the clinical notes contained in EHRs. Objective: The aim of this study is to validate the performance of the EHRead technology in identifying information of patients with CD. Methods: We used the EHRead technology to explore and extract CD-related clinical information from EHRs. To validate this tool, we compared the output of the EHRead technology with a manually curated gold standard to assess the quality of our cNLP system in detecting records containing any reference to CD and its related variables. Results: The validation metrics for the main variable (CD) were a precision of 0.88, a recall of 0.98, and an F1 score of 0.93. Regarding the secondary variables, we obtained a precision of 0.91, a recall of 0.71, and an F1 score of 0.80 for CD flare, while for the variable vedolizumab (treatment), a precision, recall, and F1 score of 0.86, 0.94, and 0.90 were obtained, respectively. Conclusions: This evaluation demonstrates the ability of the EHRead technology to identify patients with CD and their related variables from the free text of EHRs. To the best of our knowledge, this study is the first to use a cNLP system for the identification of CD in EHRs written in Spanish. © 2022 JMIR Medical Informatics. All rights reserved

    Thermal Behavior and Mechanical Properties of Y2sio5 Environmental Barrier Coatings After Isothermal Heat Treatment

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    Y2SiO5 coatings are deposited by a flame-spray technique as protection layer on SiC substrates to prevent oxidation and steam corrosion. In this research, Y2SiO5 coatings were isothermally heat treated at different temperatures and different exposure times in a laboratory environment. The thermal behaviors such as phase transformation, microstructural change and thermally grown oxide (TGO) formation have been examined by XRD, SEM, and EDS analysis. Different modes of TGO growth behavior were found at different temperatures. In addition, the mechanical properties were evaluated by a Martens hardness tester. The results show that the change of microstructure and composition is not too critical, but higher temperatures and longer heating times do lead to the formation of Y2SiO5 crystalline phases and a β-Y2O3 phase. Thus, the isothermal heat treatment improves the hardness and elastic modulus of Y2SiO5 coatings

    Deposition of Carbon Nanotubes Onto Aramid Fibers Using as-received and Chemically Modified Fibers

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    Multiwall carbon nanotubes (MWCNTs) oxidized by an acid treatment were deposited on the surface of as-received commercial aramid fibers containing a surface coating (“sizing”), and fibers modified by either a chlorosulfonic treatment or a mixture of nitric and sulfuric acids. The surface of the aramid fiber activated by the chemical treatments presents increasing density of CO, COOH and OH functional groups. However, these chemical treatments reduced the tensile mechanical properties of the fibers, especially when the nitric and sulfuric acid mixture was used. Characterization of the MWCNTs deposited on the fiber surface was conducted by scanning electron microscopy, Raman spectroscopy mapping and X-ray photoelectron spectroscopy. These characterizations showed higher areal concentration and more homogeneous distribution of MWCNTs over the aramid fibers for as-received fibers and for those modified with chlorosulfonic acid, suggesting the existence of interaction between the oxidized MWCNTs and the fiber coating. The electrical resistance of the MWCNT-modified aramid yarns comprising ∼1000 individual fibers was in the order of MΩ/cm, which renders multifunctional properties

    Pseudoneoplastic lesions of the testis and paratesticular structures

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    Pseudotumors or tumor-like proliferations (non-neoplastic masses) and benign mimickers (non-neoplastic cellular proliferations) are rare in the testis and paratesticular structures. Clinically, these lesions (cysts, ectopic tissues, and vascular, inflammatory, or hyperplastic lesions) are of great interest for the reason that, because of the topography, they may be relevant as differential diagnoses. The purpose of this paper is to present an overview of the pseudoneoplasic entities arising in the testis and paratesticular structures; emphasis is placed on how the practicing pathologist may distinguish benign mimickers and pseudotumors from true neoplasia. These lesions can be classified as macroscopic or microscopic mimickers of neoplasia
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