Browsing by Author "Leyton, Felipe"
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- ItemAntibacterial potential assessment of Nalca (Gunnera tinctoriaMol.) ethanolic extracts(2021) Velasquez, Patricia; Riquelme, Karla; Leyton, Felipe; Giordano, Ady; Gomez, Miguel; Montenegro, GloriaNalca is an edible rhubarb-type plant from the southern of Chile; with studies focussing on petiole chemical and biological properties. This work evaluated for the first time the antibacterial capacities of three organs of nalca againstEscherichia coli,Staphylococcus aureusandPseudomonas aeruginosa. Petiole (P), root (R) and flower (F) ethanolic extracts at three different concentrations (25, 50, 100 mg/mL) were evaluated by means of agar diffusion assay and MIC. The result showed that antibacterial activities are bacteria and concentration dependent, with root having the highest antimicrobial activity of the organs plant studied. Compared to commercial antibiotics, nalca extracts show promising control overPs. aeruginosa. The main polyphenolics of the extracts were identified by UPLC-MS/MS, observing for the first time caffeic, coumaric and gallic acids presence in all samples, with quercetin and rutin determined in petiole and flower extracts only. Our results contribute to better understanding of nalca attributes as potential source of antibacterial compounds to be used in nutraceutical, cosmetic and food industry.
- ItemBioactive compounds and antibacterial properties of monofloral Ulmo honey(2020) Velásquez, P; Montenegro Rizzardini, Gloria; Leyton, Felipe; Ascar, Loreto; Ramírez, O; Giordano Villatoro, Ady
- ItemBioactive polyphenols and antioxidant capacity of Azara petiolaris and Azara integrifolia Honeys(2018) Giordano Villatoro, Ady; Retamal, Mauricio; Leyton, Felipe; Martinez, Patricia; Bridi, Raquel; Velasquez, Patricia; Montenegro Rizzardini, Gloria
- ItemCombining active and passive multi-channel analysis of surface waves to improve reliability of V-S,V- 30 estimation using standard equipment(2015) Humire, Francisco; Sáez Robert, Esteban; Leyton, Felipe; Yáñez Carrizo, Gonzalo Alejandro
- ItemGeophysical Characterization of the Chilean Seismological Stations : First Results(2018) Leyton, Felipe; Leopold, Alexander; Hurtado, G.; Pasten, Cesar; Ruiz, Sergio; Montalva, Gonzalo; Sáez Robert, Esteban
- ItemReduced Graphene Oxide Overlayer on Copper Nanocube Electrodes Steers the Selectivity Towards Ethanol in Electrochemical Reduction of Carbon Dioxide(2022) Mardones-Herrera, Elias; Castro-Castillo, Carmen; Nanda, Kamala Kanta; Veloso, Nicolas; Leyton, Felipe; Martinez, Francisco; Saez-Pizarro, Natalia; Ruiz-Leon, Domingo; Jesus Aguirre, Maria; Armijo, Francisco; Isaacs, MauricioDeveloping copper-based electrocatalysts that favor high-value multi-carbon oxygenates is desired, given their use as platform chemicals and as a direct fuel for transportation. Combining a CO-selective catalyst with copper shifts the selectivity of CO2 electroreduction toward C-2 products. Herein, we developed a reduced graphene oxide (rGO)-modified copper nanocube electrocatalyst that could shift the selectivity of CO2 electroreduction towards ethanol (Faradaic efficiency 76. 84 % at -0.9 V vs. reversible hydrogen electrode (RHE)). Spectroelectrochemical Raman analysis reveals a higher population of *C2HxOy intermediates at -0.9 V vs. RHE on the rGO-modified copper nanocube electrocatalyst surface, which coincides with the highest faradaic efficiency of ethanol upon CO2 electroreduction at the same potential. Our results demonstrate that the rGO modification can enhance ethanol selectivity through a probable tandem electrocatalysis mechanism and provide insights into controlling electrocatalytic activity and product selectivity in the CO2 electroreduction reaction.
- ItemSeismic microzoning of Arica and Iquique, Chile(2015) Becerra, Alix; Podestá, Luis; Monetta, Roberto; Sáez Robert, Esteban; Leyton, Felipe; Yáñez Carrizo, Gonzalo Alejandro
- ItemThe 2014 Earthquake in Iquique, Chile : comparison between Local Soil Conditions and Observed Damage in the Cities of Iquique and Alto Hospicio(2016) Becerra, Alix; Sáez Robert, Esteban; Podestá, Luis.; Leyton, Felipe