15 research outputs found

    Solvothermal synthesis of lanthanide-functionalized graphene oxide nanocomposites

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    We propose a facile approach to the preparation of graphene oxide (GO) composites with lanthanide (Ln) oxide/hydroxide nanoparticles (Ln = La, Eu, Gd, Tb) under relatively mild conditions by two different procedures of solvothermal synthesis. The mechanism of GO-Ln nanocomposite formation is thought to involve the initial coordination of Ln3+ ions to the oxygen-containing groups of GO as nucleation sites, followed by f Ln2O3 and Ln(OH)3 nanoparticle growth. The nanocomposites obtained preserve the intrinsic planar honeycomb-like structures of graphene as proven by the typical G and D bands in the Raman spectra. Fourier-transform infrared and X-ray photoelectron spectroscopy confirm the interaction between oxygen-containing groups of GO and Ln ions. The size and distribution of Ln oxide/hydroxide nanoparticles on GO sheets, estimated from scanning and transmission electron microscopy images, vary broadly for the different lanthanides. The size can span from sub-nm dimensions for Eu oxide to more than 10 μm for Eu hydroxide nanoparticles. The most homogeneous distribution of Ln oxide/hydroxide nanoparticles was found in La-containing composites. Thermogravimetric analysis demonstrated that all the GO-Ln nanocomposites are thermally less stable, by up to 30 °C than pristine GO.</p

    Lesiones traumáticas en órganos dentarios.

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    Análisis de un cluster cervecero en México

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    Los clusters como modelo alternativo de determinadas formas de organización productiva se presentan como un ejemplo de desarrollo industrial, basado en las micro y pequeñas empresas, que además de lograr una inserción competitiva en los mercados internacionales, generan un nuevo tipo de relaciones laborales. La presente investigación se realizó con el objetivo de demostrar que existe un cluster industrial cervecero mexicano que cuenta con una gran y fuerte presencia internacional

    Bioinformatic Analysis for Mucoepidermoid and Adenoid Cystic Carcinoma of Therapeutic Targets

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    Salivary gland neoplasms are a heterogeneous neoplasm group, including mucoepidermoid carcinoma (MECa), adenoid cystic carcinoma (AdCC), and many others. Objective: We aimed to identify new critical genes of MECa and AdCC using bioinformatics analysis. Methods: Gene expression profile of GSE153283 was analyzed by the GEO2R online tool to use the DAVID software for their subsequent enrichment. Protein&ndash;protein interactions (PPI) were visualized using String. Cytoscape with MCODE plugin followed by Kaplan&ndash;Meier online for overall survival analysis were performed. Results: 97 upregulated genes were identified for MECa and 86 for AdCC. PPI analysis revealed 22 genes for MECa and 63 for AdCC that were validated by Kaplan&ndash;Meier that showed FN1 and SPP1 for MECa, and EGF and ERBB2 for AdCC as more significant candidate genes for each neoplasm. Conclusion: With bioinformatics methods, we identify upregulated genes in MECa and AdCC. The resulting candidate genes as possible therapeutic targets were FN1, SPP1, EGF, and ERBB2, and all those genes had been tested as a target in other neoplasm kinds but not salivary gland neoplasm. The bioinformatic evidence is a solid strategy to select them for more extensive research with clinical impact

    Propuesta de un plan de negocios para la empresa Exterior 9

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    Trabajo final (Contador Público, Licenciado en Relaciones Comerciales y Licenciado en Negocios Internacionales), Instituto Politécnico Nacional, ESCA, Unidad Santo Tomás, 1 archivo PDF, (151 hojas). tesis.ipn.m
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