811 research outputs found

    Emerging Technologies for Urban Traffic Management

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    Nowadays, the number of vehicles on the road and the need of transporting people grow fast. Road transportation has become the backbone of industrialized countries. Nevertheless, the road network system in cities is not sufficient to cope with the current demands due to the size of roads available. Building additional or extending existing roads do not solve the traffic congestion problem due to the high costs and the environmental and geographical limitations. As a consequence, the modern society is facing more traffic jams, higher fuel bills and high levels of CO2 emissions

    Synthesis of Nylon 6/Modified Carbon Black Nanocomposites for Application in Uric Acid Adsorption

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    High uric acid levels cause different clinic conditions. One of them is hyperuricemia, which leads to kidney damage. A solution for eliminating uric acid in the blood is by hemodialysis, which is performed using nanocomposite membranes. In this work, Nylon 6 nanocomposites were synthesized with modified carbon black (MCB), which were considered candidate materials for hemodialysis membranes. The modification of carbon black was made with citric acid using the variable-frequency ultrasound method. The new MCB was characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), transmission electron microscopy (TEM), and dispersion tests. Nylon 6/MCB nanocomposites were processed using the ultrasound-assisted melt-extrusion method to improve the dispersion procedure of the nanoparticles. The Nylon 6/MCB nanocomposites were characterized by FTIR, TGA, and differential scanning calorimetry (DSC). These were assessed for the absorption of toxins and hemocompatibility. MBC and nanocomposites showed excellent uric acid removal (78–82%) and hemocompatibility (1.6–1.8%). These results suggest that Nylon 6/MCB nanocomposites with low loading percentages can be used on a large scale without compatibility problems with blood

    DDR1 and Its Ligand, Collagen IV, Are Involved in In Vitro Oligodendrocyte Maturation

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    Discoidin domain receptor 1 (DDR1) is a tyrosine kinase receptor expressed in epithelial cells from different tissues in which collagen binding activates pleiotropic functions. In the brain, DDR1 is mainly expressed in oligodendrocytes (OLs), the function of which is unclear. Whether collagen can activate DDR1 in OLs has not been studied. Here, we assessed the expression of DDR1 during in vitro OL differentiation, including collagen IV incubation, and the capability of collagen IV to induce DDR1 phosphorylation. Experiments were performed using two in vitro models of OL differentiation: OLs derived from adult rat neural stem cells (NSCs) and the HOG16 human oligodendroglial cell line. Immunocytofluorescence, western blotting, and ELISA were performed to analyze these questions. The differentiation of OLs from NSCs was addressed using oligodendrocyte transcription factor 2 (Olig2) and myelin basic protein (MBP). In HOG16 OLs, collagen IV induced DDR1 phosphorylation through slow and sustained kinetics. In NSC-derived OLs, DDR1 was found in a high proportion of differentiating cells (MBP+/Olig2+), but its protein expression was decreased in later stages. The addition of collagen IV did not change the number of DDR1+/MBP+ cells but did accelerate OL branching. Here, we provide the first demonstration that collagen IV mediates the phosphorylation of DDR1 in HOG16 cells and that the in vitro co-expression of DDR1 and MBP is associated with accelerated branching during the differentiation of primary OLs

    DDR1 and Its Ligand, Collagen IV, Are Involved in In Vitro Oligodendrocyte Maturation

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    Discoidin domain receptor 1 (DDR1) is a tyrosine kinase receptor expressed in epithelial cells from different tissues in which collagen binding activates pleiotropic functions. In the brain, DDR1 is mainly expressed in oligodendrocytes (OLs), the function of which is unclear. Whether collagen can activate DDR1 in OLs has not been studied. Here, we assessed the expression of DDR1 during in vitro OL differentiation, including collagen IV incubation, and the capability of collagen IV to induce DDR1 phosphorylation. Experiments were performed using two in vitro models of OL differentiation: OLs derived from adult rat neural stem cells (NSCs) and the HOG16 human oligodendroglial cell line. Immunocytofluorescence, western blotting, and ELISA were performed to analyze these questions. The differentiation of OLs from NSCs was addressed using oligodendrocyte transcription factor 2 (Olig2) and myelin basic protein (MBP). In HOG16 OLs, collagen IV induced DDR1 phosphorylation through slow and sustained kinetics. In NSC-derived OLs, DDR1 was found in a high proportion of differentiating cells (MBP+/Olig2+), but its protein expression was decreased in later stages. The addition of collagen IV did not change the number of DDR1+/MBP+ cells but did accelerate OL branching. Here, we provide the first demonstration that collagen IV mediates the phosphorylation of DDR1 in HOG16 cells and that the in vitro co-expression of DDR1 and MBP is associated with accelerated branching during the differentiation of primary OLs

    Microbiota diversity in nonalcoholic fatty liver disease and in drug-induced liver injury

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    The gut microbiota could play a significant role in the progression of nonalcoholic fatty liver disease (NAFLD); however, its relevance in drug-induced liver injury (DILI) remains unexplored. Since the two hepatic disorders may share damage pathways, we analysed the metagenomic profile of the gut microbiota in NAFLD, with or without significant liver fibrosis, and in DILI, and we identified the main associated bacterial metabolic pathways. In the NAFLD group, we found a decrease in Alistipes, Barnesiella, Eisenbergiella, Flavonifractor, Fusicatenibacter, Gemminger, Intestinimonas, Oscillibacter, Parasutterella, Saccharoferementans and Subdoligranulum abundances compared with those in both the DILI and control groups. Additionally, we detected an increase in Enterobacter, Klebsiella, Sarcina and Turicibacter abundances in NAFLD, with significant liver fibrosis, compared with those in NAFLD with no/mild liver fibrosis. The DILI group exhibited a lower microbial bacterial richness than the control group, and lower abundances of Acetobacteroides, Blautia, Caloramator, Coprococcus, Flavobacterium, Lachnospira, Natronincola, Oscillospira, Pseudobutyrivibrio, Shuttleworthia, Themicanus and Turicibacter compared with those in the NAFLD and control groups. We found seven bacterial metabolic pathways that were impaired only in DILI, most of which were associated with metabolic biosynthesis. In the NAFLD group, most of the differences in the bacterial metabolic pathways found in relation to those in the DILI and control groups were related to fatty acid and lipid biosynthesis. In conclusion, we identified a distinct bacterial profile with specific bacterial metabolic pathways for each type of liver disorder studied. These differences can provide further insight into the physiopathology and development of NAFLD and DILI.This work was supported in part by a grant from the Instituto de Salud Carlos III (Spain) (PI18/01804, PI19/00883, PI21/01248), from the Consejería de Economía, Conocimiento, Empresas y Universidad (Junta de Andalucía, Spain) (PI18–RT‐3364, UMA18-FEDERJA-194), and from the Consejería de Salud (Junta de Andalucía, Spain) (PI-0285–2016). This study has been co-funded by FEDER funds (“A way to make Europe”) (“Andalucía se mueve con Europa”). CRD is supported by a grant from the Consejería de Transformación Económica, Industria, Conocimiento y Universidades de Junta de Andalucía (Spain) (DOC_01610). FMR is supported by a grant from the ISCIII (Spain) (FI19/00189). AC is supported by a grant from the ISCIII (Spain) (IFI18/00047). EGF is supported by the Nicolas Monardes program from the Consejería de Salud de Andalucía (Spain) (C-0031–2016). Funding for open access charge: Universidad de Málaga / CBUA (Spain)

    ESTUDIO DE UNA ANTENA DE MICROCINTA FRACTAL TIPO E PARA LA BANDA DE LOS 2.4 GHZ

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    ResumenEn este trabajo, se presenta el estudio experimental y por simulación de una antena de parche basada en la geometría fractal tipo E para operar en la banda libre de los 2.4 GHz. La estructura electromagnética de la antena diseñada se analiza utilizando el simulador HFSS de ANSI, mientras que el prototipo experimental se caracteriza utilizando un analizador de redes de 6.5 GHz acoplado a un equipo de medición de campo cercano para medir los parámetros importantes de esta antena. Considerando la geometría fractal tipo E de dos iteraciones, los resultados en las simulaciones muestran que la antena diseñada presenta una frecuencia de resonancia de 2.463 GHz con pérdidas por retorno cercanas a -50 dB y un ancho de banda de acoplamiento de 74 MHz. Los parámetros correspondientes en el prototipo experimental resultaron ser de 2.624 GHz, -17 dB y 100 MHz, respectivamente. Estos resultados demuestran la factibilidad de utilizar la antena de microcinta fractal tipo E para aplicaciones en las comunicaciones inalámbricas para la banda de los 2.4 GHz.Palabras Claves: ancho de banda de acoplamiento, antenas de banda ancha, antenas de microcinta, bandas sin licencia, geometría fractal tipo E. STUDY OF AN ANTENNA OF FRACTAL MICROCINTA TYPE E FOR THE BAND OF THE 2.4 GHZAbstractIn this paper, the simulation and experimental study of an E-shape fractal patch antenna for the unlicensed band of 2.4 GHz is presented. The electromagnetic structure of this antenna is analyzed using the High Frequency Structure Simulator HFSS of ANSY, while the experimental antenna prototype is characterized using a network analyzer of 6.5 GHz and a (near-field based) antenna pattern measurement equipment. Simulation results show that the designed antenna presents a resonant frequency of 2.463 GHz with return losses equal to -50 dB, and a coupling bandwidth of 74 MHz. On the other hand, the corresponding experimental parameters are 2.56 GHz, -17 dB, and 100 MHz, respectively. The study performed in this paper demonstrates the suitability of using the E-shape fractal patch antenna for wireless applications at the 2.4 GHz unlicensed band.Keywords: broadband antennas, coupling bandwidth, ISM frequency bands, patch antennas, type-E fractal geometry

    A novel learning environment for undergraduate mathematics courses

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    This work presents a scaffolding design of learning objects as auxiliaries in the teaching-learning of mathematics at undergraduate level, through an electronic learning platform developed for using in formal mathematics courses. Its design is based on the results of surveying a group of mathematics teachers in the undergraduate fields of Science and Engineering in Mexico, about different aspects of their teaching practice. This survey is consistent with other national and international studies that highlight a series of problems found in the undergraduate fields of Science and Engineering. Guidelines for the development of this kind of  learning objects were established, which leads to curricular changes that will result in an adequate process of integrating the use of technology in the classroom. An important feature of these objects is flexibility as they are helpful tools in the innovative design process. A grounded model for the creation of teaching materials is proposed, including elements that facilitate their use, and thus, it is concluded that the use of these tools is a factor that can help alleviate some of the learning problems currently present in undergraduate level mathematics courses.&nbsp
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