Examinando por Autor "Arratia-Perez, Ramiro"
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Ítem Anti-Inflammatory Chilean Endemic Plants(MDPI, 2024-03-03) Otero, Carolina; Klagges, Carolina; Morales, Bernardo; Sotomayor, Paula; Escobar, Jorge; Fuentes, Juan A.; Moreno, Adrian A.; Llancalahuen, Felipe M.; Arratia-Perez, Ramiro; Gordillo-Fuenzalida, Felipe; Herrera, Michelle; Martínez, Jose L.; Rodríguez-Díaz, MaitéMedicinal plants have been used since prehistoric times and continue to treat several diseases as a fundamental part of the healing process. Inflammation is a condition characterized by redness, pain, and swelling. This process is a hard response by living tissue to any injury. Furthermore, inflammation is produced by various diseases such as rheumatic and immune-mediated conditions, cancer, cardiovascular diseases, obesity, and diabetes. Hence, anti-inflammatory-based treatments could emerge as a novel and exciting approach to treating these diseases. Medicinal plants and their secondary metabolites are known for their anti-inflammatory properties, and this review introduces various native Chilean plants whose anti-inflammatory effects have been evaluated in experimental studies. Fragaria chiloensis, Ugni molinae, Buddleja globosa, Aristotelia chilensis, Berberis microphylla, and Quillaja saponaria are some native species analyzed in this review. Since inflammation treatment is not a one-dimensional solution, this review seeks a multidimensional therapeutic approach to inflammation with plant extracts based on scientific and ancestral knowledge.Ítem Atomic force microscopy (AFM) and 3D confocal microscopy as alternative techniques for the morphological characterization of anodic TiO2 nanoporous layers(Elsevier, 2016-02) Oyarzún, Diego P.; Linarez Pérez, Omar E.; López Teijelo, Manuel; Zúñiga, César; Jeraldo, Eduardo; Geraldo, Daniela A.; Arratia-Perez, RamiroThe morphologic characterization of self-organized TiO2 nanostructures by field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) was compared with results obtained by both atomic force microscopy (AFM) and 3D confocal microscopy, which were employed as alternative characterization methods. It is demonstrated that AFM with tuning fork configuration (intermittent mode) is also a powerful tool that allows obtaining conclusive information on the morphology of one-dimensional nanostructures. 3D confocal microscopy employed for the first time for obtaining thickness of nanoporous TiO2 films, is a new and powerful method that provides definite information on thickness of the nanostructures. The results employed for the characterization are fairly reliable besides novel and interesting. © 2015 Elsevier B.V.Ítem Comparative study of the anchorage and the catalytic properties of nanoporous TiO2 films modified with ruthenium (II) and rhenium (I) carbonyl complexes(Elsevier B.V., 2018-02) Oyarzún, Diego P.; Chardon-Noblat, Sylvie; Linarez Pérez, Omar E.; López Teijelo, Manuel; Zúñiga, César; Zarate, Ximena; Shott, Eduardo; Carreño, Alexander; Arratia-Perez, RamiroIn this article we study the anchoring of cis-[Ru(bpyC4pyr)(CO)2(CH3CN)2]2+, cis-[Ru(bpy)2(CO)2]2+ and cis-[Ru(bpyac)(CO)2Cl2], onto nanoporous TiO2 employing electropolymerization, electrostatic interaction and chemical bonding. Also, the [Re(bpyac)(CO)3Cl] rhenium(I) complex for chemical anchorage was analyzed. The characterization of TiO2/Ru(II) and TiO2/Re(I) nanocomposite films was performed by field emission scanning electron microscopy (FESEM), electron dispersive X-ray spectroscopy (EDS) and Raman spectroscopy. In addition, for the more stable nanocomposites obtained, the catalytic properties (solar energy conversion and CO2 reduction) were evaluated. The efficiency improvement in redox process derived from the (photo)electrochemical evidence indicates that modified nanoporous TiO2 structures enhance the rate of charge transfer reactions. © 2018 Elsevier B.V.Ítem Simple and Rapid One-Step Electrochemical Synthesis of Nanogranular Cu2O Films(Wiley-Blackwell, 2018-08) Oyarzún, Diego P.; Broens, Martín I.; Linarez Pérez, Omar E.; López Teijelo, Manuel; Islas, Rafael; Arratia-Perez, RamiroIn the present work, we report a simple experimental strategy for the one-step electrochemical synthesis of nanogranular Cu2O films by copper anodization in fluoride-containing ethylene glycol media. Microscopic exploration using field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM) and transmission electron microscopy (TEM), shows the formation of spherical shape grains with sizes ranging from 20 to 40 nm. Raman and X-Ray Photoemission Spectroscopy (XPS) results indicate that only CuI oxide is obtained. A band gap energy Eg=2.01 eV is estimated from UV–vis reflectance spectroscopy indicating that an indirect transition mechanism between semiconductor bands takes place. These evidences indicate that the present synthesis of nanogranular Cu2O films is a promising method for obtaining improved properties of materials for the design of photoelectronic devices. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim