This research was funded by Fondo Nacional de Desarrollo Cient?fico, Tecnol?gico y de Innovaci?n Tecnol?gica (FONDECYT) del Consejo Nacional de Ciencia Tecnolog?a e Innovaci?n Tecnol?gica (CONCYTEC) del Gobierno de Per? (Convenio de Subvenci?n 153-2015-FONDECYT). The authors would like to thank Dr. Pedro Alva-Plasencia, principal researcher of the project PIC 06-2014, for providing the laboratory equipment.

Algorithmic competences for the development of organized operations play an important role in the progress of education and learning of the logical and mathematical reasoning for children. In this context, the visual programming language Scratch is a viable tool for that purpose. Precisely, the main objective of this work is to present experiences and results of the use of that programming language with students of the primary school second year in various Chilean educational institutions, that is, in a public school, in a private school and in a private-subsidized school. These schools are in different geographical areas of the Maule region. Thanks to their social and cultural diversity along with their location, the obtained results are of a great relevance to demonstrate empirically that a significant gap does not exist for the development of algorithmic and logical-mathematical compe...

Este trabajo fue financiado por el CONCYTEC-FONDECYT en el marco de la convocatoria E041-01 [114-2018-FONDECYT-BM-IADT-MU].

RESUMEN En este trabajo de investigación se construyó un equipo para la fabricación de películas delgadas por recubrimiento mediante centrifugación (spin coating). Se usó un motor (AC/ FORDOM 2003LK 220V/60HZ) con temporizador (H5CX) para el control de las velocidades constantes de 1000 a 6000 rpm por 100 s. los cuales se lograron medir con un tacómetro óptico (LASER USB UNI-T UT372). Las películas de TiO2 fabricadas por el equipo, fueron depositadas sobres tres sustratos diferentes (ITO, Si y vidrio), las cuales fueron recocidas a 500°C después de las decima capa, con la finalidad de mejorar su estructura. Las películas fueron caracterizadas median un microscopio electrónico de barrido (MEB-T ECSAN VEGA 3 LM), difractograma de rayos X (DRX-BRUKER, D8 ADVANCED ECO) y Infrarrojo con transformada de Fourier (FITR- Thermo Scientific IS50). El DRX muestra que todas las película...

Nowadays, there is great interest in microbial fuel cells because of the different substrates that can be used in them for electric energy generation. In order to find an alternative and contribute with eco-friendly technologies, this research used the Serratia fonticola bacteria and Rhotula glutinis yeast as a fuel source through laboratory scale microbial fuel cells. A single chamber microbial fuel cell with air cathode was fabricated with a copper foil and a graphite plate as anode and cathode electrode respectively. For the characterization of the cells, physicochemical parameters such as voltage, electric current, pH and electrical conductivity were measured for 30 days and at room temperature (18 ± 2.2 °C). It was possible to generate peak voltage and current values of 0.53 ± 0.01 V and 0.55 ± 0.02 V and current values of 1.76 ± 0.16 mA and 1.52 ± 0.02 mA, for MFC...

Bacterial aminophenylpyrrole-derived alkaloids (APPAs) represent high value lead compounds. Pyrrolnitrin, which was developed into globally important fungicides, is the only reported APPA produced by Proteobacteria. Recently, various APPAs showing diverse bioactivities were discovered from Bacteroidetes. Here, a bioinformatics and phylogenetic approach enabled the elucidation of the biosynthesis of the highly diverse APPAs in Cytophagales bacteria and their chemical diversification strategy. The biosynthetic gene clusters were identified in producer strains, and the biosynthesis was experimentally validated by heterologous expression experiments in E. coli. First, one enzyme-dependent biosynthetic step yields the tryptophan-derived precursor 3-(2′-aminophenyl)-pyrrole. Second, a spontaneous Pictet–Spengler-like coupling reaction enables the bacterial producer strains to create a libr...

The microbiome of three different sites at the Peruvian Pacific coast was analyzed, revealing a lower bacterial biodiversity at Isla Foca than at Paracas and Manglares, with 89 bacterial genera identified, as compared to 195 and 173 genera, respectively. Only 47 of the bacterial genera identified were common to all three sites. In order to obtain promising strains for the putative production of novel antimicrobials, predatory bacteria were isolated from these sampling sites, using two different bait organisms. Even though the proportion of predatory bacteria was only around 0.5% in the here investigated environmental microbiomes, by this approach in total 138 bacterial strains were isolated as axenic culture. 25% of strains showed antibacterial activity, thereby nine revealed activity against clinically relevant methicillin resistant Staphylococcus aureus (MRSA) and three against enteroh...

Pineapple peels has several beneficial properties including antioxidant activity. We investigated the antioxidant effect of five different peels of pineapple lyophilized extracts, not adsorbed and adsorbed onto Amberlite. They were examined using total phenolic contents (TPC), antioxidant effect by 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging and ferric reducing antioxidant power (FRAP). In addition, we analyzed the chemical composition by HPLC-ESI-QTOF-MS/MS. The main constituents of pineapple peels were tentatively identified as quercetin glycosides and N,N’-diferuloylspermidine. We conclude that the antioxidant activity in pineapple peels from District of Poroto, Province of Trujillo, Region of La Libertad, can be associated with the presence of flavonoid and spermidines. © 2019, Universidad de Santiago de Chile. All rights reserved.