Artículos FC IFIS
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- ItemSimulations of surface charge density changes during the untreated solid tumour growth(2022-11-30)Understanding untreated tumour growth kinetics and its intrinsic behaviour is interesting and intriguing. The aim of this study is to propose an approximate analytical expression that allows us to simulate changes in surface charge density at the cancer-surrounding healthy tissue interface during the untreated solid tumour growth. For this, the Gompertz and Poisson equations are used. Simulations reveal that the unperturbed solid tumour growth is closely related to changes in the surface charge density over time between the tumour and the surrounding healthy tissue. Furthermore, the unperturbed solid tumour growth is governed by temporal changes in this surface charge density. It is concluded that results corroborate the correspondence between the electrical and physiological parameters in the untreated cancer, which may have an essential role in its growth, progression, metastasis and protection against immune system attack and anti-cancer therapies. In addition, the knowledge of surface charge density changes at the cancer-surrounding healthy tissue interface may be relevant when redesigning the molecules in chemotherapy and immunotherapy taking into account their polarities. This can also be true in the design of completely novel therapies.
- ItemMagnetic properties and applications of glass-coated ferromagnetic microwires(2023-11-10)A remarkable magnetic softness and giant magnetoimpedance (GMI) effect at GHz frequency range havebeen observed in glass-coated microwires subjected to appropriate postprocessing. Co-based microwires present higher GMI effect. Insulating and flexible glass-coating allows use of magnetically soft amorphous glass-coated microwires for stresses or temperature monitoring insmartcomposites using free space facility. Such composites with magnetic microwire inclusions can present tunable magnetic permittivity. We report on insitu the evolution of the transmission and reflection parameters of the polymer containing magnetic microwire inclusions during the polymerization process. A remarkable change of the reflection and transmission in the range of 4-7 GHz upon the matrix polymerization is observed. Observed dependencies are discussed in terms of the effect of the temperature and stresses variation on magnetic properties of glass-coated microwires during the thermoset matrix polymerization. Obtained results are considered as a base for novel sensing technique allowing non-destructive and non-contact monitoring of the composites utilizing ferromagnetic glass-coated microwire inclusions with magnetic properties sensitive to tensile stress and temperature.
- ItemInnovación educativa: explorando el impacto del aula invertida en el rendimiento académico de estudiantes de secundaria en matemática(2023-12-31)El aula invertida es un modelo pedagógico innovador que permite a estudiantes adquirir el conocimiento previo fuera del aula y luego en clase trabajar en actividades prácticas y colaborativas para aplicar y profundizar su aprendizaje. El objetivo del estudio fue evaluar el impacto del aula invertida sobre el rendimiento académico de estudiantes de nivel secundario en el área de matemática. Se realizó un estudio cuasiexperimental con un enfoque cuantitativo. La muestra incluyó 2 docentes y 134 estudiantes de tercer grado de secundaria del Liceo Ercilia Pepín de San Francisco de Macorís, República Dominicana, divididos en grupo experimental (invertido) y de control (tradicional). Se utilizó dos instrumentos: una guía de observación del proceso (cuaderno del investigador); y una prueba de conocimiento para el alumnado participante (examen), aplicada como pre-test y post-test. Además, se extrajo información importante desde las plataformas Classroom y Edpuzzle. Las calificaciones obtenidas desde las plataformas y a través de los exámenes, una vez analizados mediante pruebas estadísticas (t de Student), demostraron un impacto positivo del aula invertida en el rendimiento académico del estudiantado del grupo experimental (pre-test: M = 7.26, DE = 2.59; post-test: M = 9.12, DE = 2.87), frente al estudiantado de la clase tradicional (pre-test: M = 6.59, DE = 2.66; post-test: M = 7.22, DE = 2.77) a un nivel de significancia α = .05 y un IC de 95% (.857 - 2.940). Como conclusiones, existen diferencias estadísticamente significativas entre el rendimiento académico de estudiantes que recibieron clases de matemática mediante aula invertida y estudiantes que lo hicieron bajo una metodología tradicional. Como recomendación principal y línea futura de investigación, en virtud de la naturaleza evolutiva de las Tecnologías de la Información y la Comunicación (TIC) y su impacto en el proceso de enseñanza-aprendizaje, se sugiere a la comunidad científica que se lleven a cabo otros estudios longitudinales y comparativos para medir el progreso a lo largo del tiempo y, de esta forma, analizar cómo diferentes variables, como el acceso a la tecnología, la participación activa del alumnado y la retroalimentación constante, influyen en los resultados.
- ItemHeavy metals in the northwest agricultural region Dominican Republic(2022-05-05)Heavy metals currently represent a very important source of contamination, since their intake by humans and animals in many cases is the cause of serious damage to health. Soil, air, water and food are the most common pathways for heavy metals to reach organisms. Since soil is their origin, in this study we focus on soil analysis to determine the concentration of Cr, Ni, Cu, Zn, As, Hg, Cd and Pb, which are the most toxic metals. The study site is the agricultural soils of the northwestern region of the Dominican Republic where bananas and rice are the main crops grown. Chromium levels in most samples exceeded the NOAA-USEPA Probable Effects Level (PEL). Other heavy metals were within the acceptable ranges for healthy soil, according to the Food and Agriculture Organization (FAO).
- ItemHeavy metals in agricultural soils of San Francisco de Macorís and La Vega, Dominican Republic(2022-10-10)In Dominican Republic exists cultive larges fields of various agricultural rubles. The largest extensions are rice, banana and cocoa; these are located in the Cibao Valley. In the eastern, southwestern, and a small area in the north of the country, sugar cane is cultivated. Heavy metals are found in many of these soils that could be affecting the quality of agricultural products or production. The levels of Cr, Ni, Zn, Cu, Cd, As, Hg and Pb, determined by X-ray fluorescence spectroscopy, in soils collected in two cultivation areas of Rice de La Vega and San Francisco de Macoris (SFM) have been compared with the NOAA-USEPA Canadian Agricultural Soil and Sediment Guide (CEQGs) (SQuiRTs Table). The levels of Cr and Ni in La Vega exceeded the threshold effects levels (TEL), and the probable effects levels (PEL). Pb levels in the La Vega area were higher than in SFM. In general, these metals are found in the La Vega area in higher concentrations than in SFM, exceeding PEL and TEL.