With ab-initio calculation carried out the analysis of the electronic properties of the topaz in its fundamental state, with different concentrations of Fluorina (F^(-)) and Hidroxilo (OH^(-)) ions, using the package TB-LMTO-ASA. This compound presents optic properties in its natural form with different concentrations of [F^(-),OH^(-)], as well as to the interaction with ionizing radiation. As a result we will have that as much the total energy as the gap fall in non lineal form to the increase of OH ions, being the topaz with 100% F is but stable that the topaz with OH^(-). Product of this increase takes place a phase transformation, increasing of volume and lowering the energy of Ferrni.

Using the base "Augmented Spherical Waves (ASW)" the quantities are calculated and discuss "Orbital Crystal Overlap Population (COOP)" and "Orbital Crystal Hamiltonian Population (COHP)" that give information about the formation of states bonding and antibond1ng and consequently on the stability in the system YBa2Cu3O7. The calculation realizes in the reg1on of the crystalline cell that it shows superconductivity. There is demonstrated that in the region is highly unstable in the state not superconductor with a great quantity of states antibonding lor below and in the energy of Fermi E(F). This situation can induce a transit1on of local phase to the state superconductor.

With ab-initio calculation carried out the analysis of the electronic properties of the topaz in its fundamental state, with different concentrations of Fluorina (F^(-)) and Hidroxilo (OH^(-)) ions, using the package TB-LMTO-ASA. This compound presents optic properties in its natural form with different concentrations of [F^(-),OH^(-)], as well as to the interaction with ionizing radiation. As a result we will have that as much the total energy as the gap fall in non lineal form to the increase of OH ions, being the topaz with 100% F is but stable that the topaz with OH^(-). Product of this increase takes place a phase transformation, increasing of volume and lowering the energy of Ferrni.

Using the base "Augmented Spherical Waves (ASW)" the quantities are calculated and discuss "Orbital Crystal Overlap Population (COOP)" and "Orbital Crystal Hamiltonian Population (COHP)" that give information about the formation of states bonding and antibond1ng and consequently on the stability in the system YBa2Cu3O7. The calculation realizes in the reg1on of the crystalline cell that it shows superconductivity. There is demonstrated that in the region is highly unstable in the state not superconductor with a great quantity of states antibonding lor below and in the energy of Fermi E(F). This situation can induce a transit1on of local phase to the state superconductor.

This work has been supported by Peru's Consejo Nacional de Ciencia y Tecnologia (CienciActiva - CONCYTEC) and the British Embassy in Lima [contract numbers 154-2015 and 002-2016]. Portions of this research were conducted with the advanced computing resources provided by Texas A&M High Performance Research Computing. Ms. Karinna Visurraga (UTEC) is kindly acknowledged for administrative support.

Con datos hidrográficos de dos prospecciones, realizadas en marzo y setiembre 2014, se describe la hidrografía y estratificación en la bahía de Miraflores (BM) asociadas a condiciones cálidas y frías en ambos periodos. En marzo se presentó una condición estratificada y cálida, con máximos valores de frecuencia de Brunt Väisälä (FBV) y de vorticidad potencial (VP); asimismo la termoclina, haloclina y picnoclina fueron pronunciadas, debido principalmente a la mayor radiación solar recibida. En setiembre, la columna de agua fue más homogénea y fría con presencia de una capa de mezcla débil y somera. La distribución de la temperatura potencial, salinidad y densidad potencial tuvo una relación directa con la estacionalidad y con la configuración de la bahía en el aspecto espacial. Se espera que los resultados obtenidos en el presente estudio contribuyan a un conocimiento...

Cyanidation (leaching with cyanide) is a common yet complex surface process in hydrometallurgical practice, and its effectiveness in extracting the metal of interest is often affected by the nature of the mineralogical species that are present. Little is known about surface processes on acanthite (a silver sulfide) and how its various facets respond to cyanidation in aqueous solution. Therefore, in this work, some properties of both bulk acanthite (Ag2S) and its (001), (022), and (1̅21) surface facets have been studied by density-functional-theory (DFT)-based calculations to elucidate reactivity trends and competitive adsorption (initial stages in the surface process of cyanidation) between cyanide and other species present in the leaching liquor. It is found that CN– binds by its C-end to silver sites on the acanthite surface with adsorption energy similar to that of OH– but strong...

Se presenta en el presente trabajo las características principales del alambique modificado de acero inoxidable a nivel de laboratorio, construido en un proyecto de investigación del año 2014. La puesta en funcionamiento se hicieron con ensayos de mosto fermentado de uva quebranta proveniente del Valle de Lunahuana, Cañete, obteniéndose pisco de aceptable calidad.

Se presenta en el presente trabajo las características principales del alambique modificado de acero inoxidable a nivel de laboratorio, construido en un proyecto de investigación del año 2014. La puesta en funcionamiento se hicieron con ensayos de mosto fermentado de uva quebranta proveniente del Valle de Lunahuana, Cañete, obteniéndose pisco de aceptable calidad.

Aim: This retrospective study determined features associated with brain metastasis (BM) in women with breast cancer. Patients & methods: A total of 215 initially early breast cancer cases were included. We reviewed files and CT scan images of BM. Results: Median age was 47 years and most of our cases were stage III (58.6%), grade III (62.8%), ER negative (62.3%) and nonluminal (59.1%). Median survival after BM was 4 months. Nonluminal, extracranial disease, time to CNS shorter than 15 months, >three brain lesions and poor breast-graded prognostic assessment and recursive partitioning analysis scores were associated with shorter survival. Adding extracranial disease to breast-graded prognostic assessment score also predicted survival after BM. Radiation response was assessed in 57 patients and response tended to be associated with nonluminal phenotype but not with survival. Conclus...

YBa2Cu3(O)7-x thin film sample was studied by micro-Raman spectroscopy. The investigation involved aspects like crystal orientation, uniformity, secondary phases, impurities, oxygen content and defects, based on the speciftc Raman selection rules for YBa2Cu3(O)7-x and polarized Raman scattering experiments.

YBa2Cu3(O)7-x thin film sample was studied by micro-Raman spectroscopy. The investigation involved aspects like crystal orientation, uniformity, secondary phases, impurities, oxygen content and defects, based on the speciftc Raman selection rules for YBa2Cu3(O)7-x and polarized Raman scattering experiments.

Introduction: The COVID-19 pandemic has generated diverse reactions, but these have not yet been measured in the Latin American population. Objective: To determine the factors associated with the perception of fatalism in the face of COVID-19 infection in inhabitants of 20 cities in Peru. Material and Methods: A cross-sectional, multicenter study with a sample size of 2 466 people from 20 cities of Peru that measured fatalism during the COVID-19 pandemic was conducted through a validated survey (Cronbach's alpha: 0,78) consisting of 7 items. Statistical analysis was conducted in terms of each city, and p < 0,05 was considered significant. Results: Of the 2 466 respondents, 36 % were depressed, 26 % thought that they might die, 17 % say that this was evidence of the end of the world, and 9 % could make a fatal decision. Women were more likely to engage in three of the fatalistic behaviors...

Introduction: Fear is a natural response to something unknown. In the current scenario, it is important to assess it in relation to the coronavirus disease-19 (COVID-19) pandemic in Latin American countries. Objective: To determine the fear perception according to factors associated with the COVID-19 pandemic in Peru. Methods: An analytical cross-sectional study was conducted based on a virtual questionnaire. The main question was “how much fear people had of COVID-19?”, using a scale from zero (without fear) to 10 (very fear). This scale was divided into tertiles, and the upper tertile was the reference category (compared to the middle and lower tertiles). Statistical significances between fear perception of COVID-19 and sociodemographic data were calculated. Results: A total of 3887 participants responded the questionnaire about fear perception. In the multivariate analysis was fou...