Quantitative representation of reactivity, selectivity and site activation concepts in organic chemistry

Indexación: ScieloReactivity, selectivity and site activation are classical concepts in chemistry which are amenable to quantitative representation, in terms of static global, local and non local density response functions. The use of these electronic indexes describing chemical interconversion is developed in this work along the perspective of the pioneering work conducted in Chile by the late Professor Fernando Zuloaga, to whom this article is dedicated in memoriam. While global responses, represented as derivatives of the electronic energy with respect to the total number of electrons quantitatively describe the propensity of a system to interconvert into another chemical species (chemical reactivity), the local counterparts assesses well those regions in the molecule where the reactivity pattern dictated by the global quantities is developed (selectivity). Site activation /deactivation may in turn be described by the variations in the local or regional patterns of reactivity, that may be induced by solvent effects or chemical substitution. These concepts are illustrated for a series of chemical reactions in Organic Chemistry, including electrocyclic processes, cycloadditions and electrophilic addition reactions. Some relationships between quantitative scales of reactivity and reaction mechanisms are discussed.http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-97072004000100010&lang=p

Gestión a la seguridad alimentaria en Colombia

En el siguiente ensayo se hace un análisis sobre las herramientas que pueden ser útiles, en la ocurrencia de una crisis de la seguridad alimentaria, tomando como referente, lo descrito por Cartagena (2005) que: En los últimos quince años, Colombia ha venido descuidando un sector tan primordial como lo es el agropecuario. Uno de los motivos por el cual la alimentación viene siendo ya no un derecho suplido por el Estado, sino que se ha convertido en una necesidad primaria de todo ser humano . De lo mencionado anteriormente se puede interpretar que el tema del sector agropecuario, y principalmente el de la producción, es desconocido, con respecto a la desigualdad de la distribución del ingreso y la riqueza del País

Trabajo Fin de Máster: Reflections upon my personal growth as an English Teacher

This is a dissertion in which I reflect on two important works: the syllabus and the learning unit, showing my personal growth during this year as an English teacher, highlighting some of the most important ideas to take into account in my future career

The Dark Side of the Self-Determination Theory and Its Influence on the Emotional and Cognitive Processes of Students in Physical Education

Amongst the main objectives of physical education (PE) classes is the consolidation of healthy lifestyle habits in young people and adolescents. Nonetheless, these classes can also provide the basis from which adverse experiences are generated which affect students’ perceptions of these classes. Previously conducted studies have focused on motivational processes and not on emotional processes, nor on the way in which students learn. The objective of the present study was to explore the dark side of the self-determination theory, its influence on emotional intelligence and the meta-cognitive strategies of students. Methodology: A total of 1602 young people undertaking secondary education participated, with self-reported ages between 13 and 19 years. The following questionnaires were utilized: Controlling Coach Behaviors Scale, Frustration of Psychological Needs in PE classes Scale, Emotional Intelligence in PE Scale and Motivated Strategies for Learning Questionnaire. A structural equation model was developed which explained causal associations between the study variables. Results: Psychological control positively predicted each one of the sub-factors of frustration of psychological needs. Frustration of psychological needs negatively predicted emotional intelligence. Finally, emotional intelligence positively predicted meta-cognitive thinking. Conclusions: The influence and importance of the teaching style adopted by teachers is indicated, in addition to the effect of students’ psychological experiences on emotions and learning strategie

Modeling neural differentiation on micropatterned substrates coated with neural matrix components

Topographical and biochemical characteristics of the substrate are critical for neuronal differentiation including axonal outgrowth and regeneration of neural circuits in vivo. Contact stimuli and signaling molecules allow neurons to develop and stabilize synaptic contacts. Here we present the development, characterization and functional validation of a new polymeric support able to induce neuronal differentiation in both PC12 cell line and adult primary skin-derived precursor cells (SKPs) in vitro. By combining a photolithographic technique with use of neural extracellular matrix (ECM) as a substrate, a biocompatible and efficient microenvironment for neuronal differentiation was developed

Autocuidado do cuidador informal de idosos em alguns países da América Latina: Revisão descritiva

Introduction: The family is responsible for the care of the elderly, giving rise to the informal caregiver. Objective: To describe the self-care of the informal caregiver of the elderly in some Latin American countries. Methodology: Descriptive review, on the following databases: PubMed, Scopus, SciELO, Web of Science, Redalyc and Dialnet; analyzing full-text scientific articles of the last 13 years (2009-2022) in Spanish, English and Portuguese. Complementary documents related to the subject were searched on Web pages of national institutions of Latin American countries. Results: The analysis of the 25 scientific articles and 4 selected documents allowed to identify 4 axes: concepts of care, caregiver and types of caregivers; health of the informal caregiver of the elderly; theoretical basis of self-care and implementation of programs to care for the caregiver in some Latin American countries. Conclusions: It is evident that the self-care of caregivers of older people is decreased, directly affecting the health of this. Several Latin American countries support the informal caregiver, however, there is still much to be done for caregivers.Introducción: La familia es la responsable del cuidado a la persona mayor, lo que da origen al cuidador informal. Objetivo: Describir el autocuidado del cuidador informal de personas mayores en algunos países de Latinoamérica. Metodología: Revisión descriptiva en las bases de datos PubMed, Scopus, SciELO, Web of Science, Redalyc y Dialnet, de artículos científicos a texto completo de los últimos 13 años (2009-2022) en idioma español, inglés y portugués; complementariamente se buscaron documentos referentes al tema en páginas web de instituciones nacionales de países latinoamericanos. Resultados: El análisis de los 25 artículos científicos y 4 documentos seleccionados permitieron identificar 4 ejes: conceptos de cuidado, cuidador y tipos de cuidadores; salud del cuidador informal de la persona mayor; base teórica del autocuidado, e implementación de programas para cuidar al cuidador en algunos países latinoamericanos. Conclusiones: Se evidencia que el autocuidado de los cuidadores de personas mayores está disminuido, lo que afecta directamente la salud de este. Varios países de Latinoamérica apoyan al cuidador informal, sin embargo, todavía hay mucho por hacer por las personas que cumplen la labor del cuidado.  Introdução: A família é responsável por cuidar do idoso, dando origem ao cuidador informal. Objetivo: Descrever o autocuidado do cuidador informal de idosos em alguns países da América Latina. Metodologia: Revisão descritiva nas bases de dados PubMed, Scopus, SciELO, Web of Science, Redalyc e Dialnet; artigos científicos em texto completo dos últimos 13 anos (2009-2022) em espanhol, inglês e português; foram pesquisados ​​documentos complementares referentes ao assunto em páginas da Web de instituições nacionais de países da América Latina. Resultados: A análise dos 25 artigos científicos e 4 documentos selecionados permitiu identificar 4 eixos: conceitos de cuidado, cuidador e tipos de cuidadores; saúde do cuidador informal do idoso; base teórica do autocuidado e implementação de programas de cuidado ao cuidador em alguns países da América Latina. Conclusões: É evidente que o autocuidado dos cuidadores de idosos está diminuído, afetando diretamente sua saúde. Vários países da América Latina apoiam o cuidador informal, porém, ainda há muito a ser feito pelas pessoas que realizam o trabalho de cuidar

Estudio de cobertura en 5G con ICS Telecom: análisis de perdidas por factores climatológicos en tecnología 5G para las zonas metropolitanas de la ciudad de Bogotá D.C.

In this project is has been made a study and later coverage analysis for a cellular telecommunication network in 5G technology a metropolitan scenario of Bogota city, Colombia. It starts, with an explanation of what is 5G and what is expected of this technology. With this preamble, it’s established the parameters of simulation for 5G technology, defining the frequency 3 GHz until 100 GHz, what it entails the use of millimeter waves. For the base stations in the simulations, it was made given two operators of the five existing in the country (operators X and Y). The scenario was chosen with the purpose of study the case most presented in the moment of develop and design of cellular telecommunication system as are the systems without line of sight (NLOS) which is observed on the Universidad Nacional de Colombia facilities, where are wide green zones and buildings between 4 and 10 floors. In agreement to the results it's evidence that the free space losses of signal high signal loss due to the to the multiple obstacles with they encounter. In the simulations were taken into account the climatological effects as rain and fog that increase the signal loss.En este proyecto se realizó un estudio y su posterior análisis de cobertura para una red en tecnología 5G en un escenario metropolitano de la ciudad de Bogotá, Colombia. Se inicia, con una explicación de qué es 5G y qué se espera de esta tecnología. Con este preámbulo se establecieron los parámetros de simulación para la tecnología 5G, definiendo las frecuencias de 3 GHz hasta los 100 GHz, lo que conlleva al uso de ondas milimétricas. Para la ubicación de las estaciones base para las simulaciones, se realizaron teniendo en cuenta dos operadores de los cinco existentes en el país (operadores X y Y).  El escenario fue elegido con el propósito de estudiar el caso más presentado en el momento de desarrollo y diseño del sistema de telecomunicaciones celulares como son los sistemas sin línea de visión (NLOS) que se observa en las instalaciones de la Universidad Nacional de Colombia, donde se encuentran zonas verdes amplias y edificios entre 4 y 10 pisos. De acuerdo a los resultados obtenidos se evidencia que la perdida de señal en el espacio libre es elevada debido a los múltiples obstáculos con los que se encuentra. En las simulaciones se tuvieron en cuenta los efectos climatológicos como la lluvia y la niebla que incrementan las pérdidas de la señal

La jurisdiscción y la adiministración de justicia em Venezuela em el marco de la Constitución de 1999

La función jurisdiccional y la organización del llamado “Poder Judicial” en Venezuela, será el tema a describir en las presentes páginas. Para ello, se tomó como base y estructura principal, los trabajos del Profesor Roberto Bergalli que abordan los conceptos fundamentales que deben tomarse en cuenta para realizar un análisis sociojurídico sobre el  tema. Primeramente y de manera muy breve, se realizará la distinción entre función jurisdiccional y  poder judicial, para luego describir los principales elementos que deben ser tomados en cuenta  en el estudio del tema de la independencia de la jurisdicción y de la administración de justicia en sus dos dimensiones: interna y externa y el tema del autogobierno judicial, para culminar con la revisión de los principios constitucionales que le dan forma a la jurisdicción y administración de justicia en Venezuela, intentando observar en cada una de sus características el apego o no a los conceptos mencionados precedentemente

Modelo preditivo de o grau de incapacidade em adultos com lesão medular: resultados da WHO-DAS II

Objective: To establish a prediction model of the degree of disability in adults with Spinal CordInjury (SCI ) based on the use of the WHO-DAS II . Methods: The disability degree was correlatedwith three variable groups: clinical, sociodemographic and those related with rehabilitation services.A model of multiple linear regression was built to predict disability. 45 people with sci exhibitingdiverse etiology, neurological level and completeness participated. Patients were older than 18 andthey had more than a six-month post-injury. The WHO-DAS II and the ASIA impairment scale(AIS ) were used. Results: Variables that evidenced a significant relationship with disability were thefollowing: occupational situation, type of affiliation to the public health care system, injury evolutiontime, neurological level, partial preservation zone, ais motor and sensory scores and number ofclinical complications during the last year. Complications significantly associated to disability werejoint pain, urinary infections, intestinal problems and autonomic disreflexia. None of the variablesrelated to rehabilitation services showed significant association with disability. The disability degreeexhibited significant differences in favor of the groups that received the following services: assistivedevices supply and vocational, job or educational counseling. Conclusions: The best predictiondisability model in adults with sci with more than six months post-injury was built with variablesof injury evolution time, AIS sensory score and injury-related unemployment.Objetivo: Establecer un modelo predictivo del grado de discapacidad en adultos con lesión medulara partir de la utilización del WHO-DAS II . Materiales y Métodos: Se correlacionó el grado dediscapacidad (por áreas y final) con variables sociodemográficas, clínicas y relacionadas con los serviciosde rehabilitación y se construyó un modelo de regresión lineal múltiple para discapacidad.Participaron 45 personas con lesión medular de variada etiología, nivel neurológico y completitud,mayores de 18 años con más de seis meses de evolución. Se utilizó el WHO-DAS II y la escala dedeficiencia ASIA . Resultados: Las variables que evidenciaron relación significativa con la discapacidadfueron: situación ocupacional, tipo de afiliación al sistema público de salud, tiempo de evolución,nivel neurológico, zona de preservación parcial, índices motor y sensitivo ASIA y número decomplicaciones clínicas en el último año. Las complicaciones que se asociaron significativamentecon la discapacidad fueron dolor articular, infecciones urinarias, problemas intestinales y disreflexiaautonómica. Ninguna de las variables asociadas a servicios de rehabilitación presentó asociaciónsignificativa con la discapacidad. Los únicos servicios que mostraron diferencia significativa entreel grupo que los recibió y el que no, en relación con la discapacidad, fueron el suministro de aditamentosy la orientación vocacional, laboral o educativa. Conclusiones: El mejor modelo predictivode discapacidad en adultos con lesión medular con más de seis meses de evolución se construyó conlas variables tiempo de evolución, índice sensitivo ASIA y desempleo por la lesión.Objetivo: Estabelecer um modelo preditivo do grau de deficiência em adultos com lesão medular apartir da utilização do WHO-DAS II Metodologia: correlacionou-se o grau de deficiência (por árease final) com variáveis sócio-demográficas, clínicas e relacionadas com os serviços de reabilitação econstruiu-se um modelo de regressão lineal múltiple para deficiência. Participaram 45 pessoas comlesão medular de variada etologia, nível neurológico e plenitude, maiores de 18 anos, com mais deseis meses de evolução. Utilizou-se o WHO-DAS II e a escala de deficiência ASIA. Resultados: Asvariáveis que evidenciaram relação significativa com a discapacidade foram: situação ocupacional,tipo de afiliação ao sistema público de saúde, tempo de evolução, nível neurológico, zona de preservaçãoparcial, índices motor e sensitivo ASIA e número de complicações clínicas no último ano.As complicações se associaram significativamente com a deficiência foram dor articular, infecçõesurinarias, problemas intestinais e disreflexia autonômica. Nenhuma das variáveis associadas a serviçosde reabilitação apresentou associação significativa com a deficiência. Os únicos serviços quemostraram diferença significativa entre o grupo que os recebeu e o grupo que não, em relação coma deficiência, foram o fornecimento de aditamentos e a orientação vocacional, laboral ou educativa.Conclusões: o melhor modelo preditivo de deficiência em adultos com lesão medular com maisde 6 meses de evolução se construiu com as variáveis: tempo de evolução, índice sensitivo ASIA edesemprego pela lesão

Nefritis del shunt

Shunt nephritis is a rare complication associated with the use of atrialventricular shunts and their chronic infection. The microorganisms that cause the infection are generally of low virulence, but they can produce long term infections that permit the production of immune complex that deposit in the kidneys leading to nephritis. Because of this we want to describe the case of an adolescent patient with hydrocephalus, as a consequence of meningitis in the childhood, and chronic use of atrialventricular shunts. She presented fever and child for a long time, these symptoms were secondary to infection of the device, and shunt nephritis was also present.La nefritis por shunt es una complicación poco frecuente que se asocia al uso de derivaciones ventriculoatriales y su infección crónica. Las bacterias que la producen, por lo general, son de baja virulencia, pero producen infección prolongada y persistente permitiendo así la producción de inmunocomplejos que se depositan a nivel renal. Queremos describir un caso de una adolescente con hidrocefalia posterior a un evento de meningitis, con uso de derivación ventrículoatrial quien ingresa con un cuadro de fiebre y escalofrío de larga evolución, en la cual se documentó infección del dispositivo y nefritis por shunt