The effect of the electromagnetic field on the physicochemical properties of isolated corn starch obtained of plants from irradiate seeds.

Maize grains are composed of the pericarp, endosperm, and germ. Consequently, any treatment, such as electromagnetic fields (EMF) must alter these components, which in turn alters the physicochemical properties of the grain. Since starch is a major component of corn grain, and given the great industrial importance of starch, this study investigates how EMF affects the physicochemical properties of starch. Mother seed were exposed to three different intensities 23, 70, and 118 µT for 15 days. Except for a slight porosity on the surface of the starch of the grains of plants exposed to higher EMF, the starch showed no morphological differences between the different treatments and the control (according to scanning electron microscopy). The X-ray patterns showed that the orthorhombic structure was kept constant, unaffected by the intensity of EMF. However, the pasting profile of starch was affected, and a decrease in the peak viscosity was obtained when the intensity of EMF increased. In contrast to the control plants, FTIR shows characteristic bands which can be attributed to the stretching of the CO bonds at wave number 1.711 cm-1. EMF can be considered a physical modification of starch.

eDNA extraction protocol for metagenomic studies in tropical soils.

The lack of knowledge about biological communities residing in soils, especially those in tropical regions, represents a constraint to management practices to take advantage of the ecological services provided by soil microbiota to agroecosystems. One of the complexities derived from describing biological diversity in such tropical conditions comes from the methods used to isolate microorganisms without altering the composition of the sample. The goal of this study was to establish a protocol for adequate soil sampling and environmental DNA extraction from a tropical region in Costa Rica. We present an up-to-date protocol optimized for tropical soils which improves sevenfold the amount of DNA extracted without significantly affecting the 260/280 and 260/230 ratios compared with commercially available kits and standard protocols.

Desorption of Furfural from Bimetallic Pt-Fe Oxides/Alumina Catalysts.

In this work, the desorption of furfural, which is a competitive intermediate during the production of biofuel and valuable aromatic compounds, was studied using pure alumina, as well as alumina impregnated with iron and platinum oxides both individually and in combination, using thermogravimetric analysis (TGA). The bimetallic sample exhibited the lowest desorption percentage for furfural. High-resolution transmission electron microscopy (HRTEM) imaging revealed the intimate connection between the iron and platinum oxide species on the alumina support. The mechanism of furfural desorption from the Pt-Fe/Al2O3 0.5%-0.5% sample was determined using physisorbed furfural instead of chemisorbed furfural; this mechanism involved the oxidation of the C=O group on furfural by the catalyst. The oxide nanoparticles on γ-Al2O3 support helped to stabilize the furfural molecule on the surface.

Correlación entre el desarrollo psicomotor y el rendimiento escolar en niños de primer año de educación básica, pertenecientes a establecimientos municipales de dos comunas urbanas de la Región Metropolitana / Correlation between psychomotor development and academic performance of first grade children who attended public schools from two urban districts of the Metropolitan Region

El presente estudio correlacional, cuantitativo y no experimental, tiene por objeto determinar si existe relación entre el Desarrollo Psicomotor y el Rendimiento Escolar de niños de primer año básico pertenecientes a escuelas municipalizadas de la Región Metropolitana. Se evaluó una muestra de 106 niños a través del Manual de Observación Psicomotriz de Vitor da Fonseca, para determinar el desarrollo psicomotor, por otra parte, para establecer el Rendimiento Escolar se enfocó en las asignaturas de Lenguaje y Matemáticas, evaluadas a través de cuatro procedimientos: Prueba de Funciones Básicas (PFB) e Índice Lenguaje (IL) (notas-simce) para Lenguaje y Prueba de Precálculo (PPC) e Índice Matemáticas (IM) (notas-simce) para Matemáticas. Los resultados muestran una correlación ordinal estadísticamente significativa (p<0,01) entre el Desarrollo Psicomotor y cada una de las cuatro evaluaciones del Rendimiento Escolar, según el coeficiente de Spearman y la Prueba de t de Student. Además, se buscaron asociaciones significativas entre cada una de las áreas del Desarrollo Psicomotor y ambas pruebas Rendimiento Escolar. Los resultados indican que para la Prueba de Funciones Básicas sólo existe una asociación significativa estadísticamente, con el área de Praxia Fina (p<0,01), mientras que la Prueba de Precálculo se asocia significativamente con las áreas de Estructuración Temporo-Espacial (p<0,01), Praxia Global (p<0,05) y Praxia Fina (p<0,05). En conclusión, existe una correlación ordinal significativa entre el Desarrollo Psicomotor y el Rendimiento Escolar en niños de primer año básico.

Traumatismo abdominal cerrado: revisión de 53 casos atendidos en el Hospital Central Militar / Closed abdominal trauma: a 53 case review seen at the Central Military Hospital

Se revisa el caso de 53 individuos con traumatismo abdominal cerrado atendidos en el Hospital Central Militar. Las principales causas de traumatismo abdominal cerrado fueron: accidentes automovilísticos (28 por ciento), agresiones (15 por ciento) y los accidentes por atropellamiento de un vehículo automotor (15 por ciento). La mayor parte de las contusiones del abdomen implican el abordaje amplio para descartar lesiones en órganos blandos, por lo que la laparotomía exploratoria está indicada en su manejo y posterior tratamiento. De esta revisión se concluye que el manejo de este tipo de lesiones en la sala de urgencias del Hospital Central Militar y su posterior evolución en las salas de cirugía es satisfactoria