3 resultados para cloreto de 2,3,5 trifeniltetrazólio

em Repositório Científico da Universidade de Évora - Portugal


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O presente estudo aborda a problemática dos alunos de risco no 2° Ciclo da E.B. 2,3 Ana de Castro Osório, no ano letivo 2004/2005. Na dimensão teórica são referenciadas algumas questões de Organização Escolar (escola reflexiva, autonomia de escola, gestores intermédios e supervisão escolar, o papel do Diretor de Turma, o Projeto Curricular de Escola, algumas linhas orientadoras da política educativa portuguesa, no período em que decorre a elaboração desta investigação) e abordados alguns aspetos gerais dos pré-adolescentes, diversos conceitos de risco, a ação de diversas entidades com competência na área da infância e juventude, o papel da família e a relação desta com a escola. Foi utilizada a metodologia do “Estudo Caso”, no decurso da qual foram analisados documentos internos da escola e elaborados instrumentos de recolha de dados (questionários aplicados aos Alunos e aos seus Diretores de Turma). No tratamento das informações de natureza quantitativa, utilizou-se o programa informático Excel, enquanto nas questões abertas procedeu-se à análise de conteúdo. Em síntese, concluiu-se que: a) um terço dos alunos que frequentava o 2° Ciclo do Ensino Básico, foi sinalizado como “aluno de risco”. Cerca de 75% era do 5° Ano de Escolaridade. Os fatores de risco que mais se destacam são: assiduidade irregular, desmotivação/desinteresse/apatia, défice de atenção e concentração, indisciplina e retenções sucessivas no seu percurso escolar. A família é pouco participativa. b) a resposta curricular dá-se essencialmente dentro da sala de aula; c) a resposta organizacional assenta essencialmente nalgumas medidas previstas nos documentos legislativos. Na última parte do trabalho deixamos expressas as conclusões do estudo mais pormenorizadas, bem como algumas recomendações/sugestões que eventualmente, poderão orientar posteriores investigações. /ABSTRACT - The risk students on a 2nd Cycle of classroom of the E.B. 2, 3 Ana de Castro Osório, during academic year of 2004/2005: A Case study The present study attempts to assess risk students on a 2nd Cycle (Sth and 6th grades) classroom of the “E.B. 2, 3 Ana de Castro Osório” Public School during the academic year of 2004/2005. On a theoretical scale, are assessed some questions about the Classroom Organization (reflexive school, school autonomy, intermediate directors and school supervision, the role of the Class Tutor, the School Curricular Project, some guidelines about the Portuguese education policy during the period when this study took place), and was also assessed some general aspects of preadolescents, risk concepts, and actions taken by various organizations specialized in the areas of childhood and youth, the role of the family and the interrelation between the family and the school. It was used a “Case Study” methodology during which was assessed school documents of this particularly school, and data collecting instruments (Student-applied and Class Tutor-applied questionnaires). On dealing with quantitative data, it was used the Excel application, while for the open questions was assessed by its contents. In brief, it was concluded that: a) a third of students that attended the 2nd Cycle Basic Education schools revealed to be “risk students”. Around 75% of them were 5th grade students. Among the most important risk factors are: irregular attendance, unmotivated/aloofness /apathy, lack of attention and concentration, indiscipline and successive retentions during their education pathway. The family is scarcely participative. b) The curricular response is normally given within the classroom; c) the organizational response lies mostly on some measures included in government documents. On the last part of the paper, we focus on more detailed conclusions, as well as give recommendations/suggestions which may eventually be of guidance to future studies.

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1,2,4,5-Tetrazines are six-membered heterocyclic compounds in which the four nitrogen atoms are displayed in a symmetric fashion. Their reactivity is quite different from other heterocyclic aromatic systems due to its unique electron-withdrawing character, comparable to tetra-nitrobenzene. 1 In particular, 1,2,4,5- tetrazines are known to take part in [4+2] inverse-Diels–Alder cycloaddition processes which efficiently lead to the construction of substituted pyridazine systems that are important in drug development and biomarker applications. 2 However, the electronic character of 1,2,4,5-tetrazines hampered the development of 3- ethynyl- and 3,6-diethynyl-1,2,4,5-tetrazine derivatives for molecular electronic applications, proved by the scarcity of examples found in the literature. 3 Herein, we describe the synthesis and characterization of two novel ethynyl-based 1,2,4,5-tetrazine derivatives. Synthesis of 3,6-(4-bromophenyl)-1,2,4,5-tetrazine precursor (1) was achieved in good yield by Pinner’s method, starting from 4-bromobenzonitrile. Despite its low solubility in common organic solvents, this precursor was found to react smoothly under typical Sonogashira coupling conditions to selectively afford the 3-ethynyl (2) and 3,6-diethynyl (3) protected derivatives (Figure 1). Reaction conditions were evaluated in order to provide the best yields and to promote selectivity of the mono- or disubstituted ethynyl derivatives. Finally, deprotection was achieved affording, in the case of compound 3, an unprecedented 3,6- diethynyl-1,2,4,5-tetrazine compound. Time-Dependent Density Functional Theory (TDDFT) calculations for both deprotected ethynyl derivatives were used to simulate electronic spectra. A deep knowledge of the relevant electronic transitions involved and quantitatively satisfactory results of the calculated electronic excitations in comparison with experimental data were obtained.

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O presente relatório surge como um complemento à minha Prática de Ensino Supervisionada, realizada no ano lectivo de 2009/201O, visando essencialmente a reflexão e documentação do trabalho por mim desenvolvido ao longo deste ano. A minha Prática de Ensino Supervisionada debruçou-se sobre a disciplina de Educação Física, e decorreu na Escola EB 2,3 Conde de Vilalva, onde leccionei a disciplina a uma turma de 8° ano, e na Escola Secundária André de Gouveia, tendo leccionado a disciplina a um 12° ano. Durante este mesmo ano lectivo, leccionei ainda entre 8 intervenções a uma turma do 1° Ciclo de Ensino Básico, 1° ano; e 9 intervenções a uma turma do 2° Ciclo de Ensino Básico, o 5° ano. ABSTRACT: This document comes as a complement to my Supervised Teaching Practice, held in the 2009/201O academic year, aiming primarily to reflection and documentation of the work developed throughout this year. My Supervised Teaching Practice was focused on the discipline of Physical Education, and held at EB 2,3 Conde de Vilalva where I taught a class in 8th grade, and in high school André de Gouveia, where I taught the discipline to a class in 12th grade. During that same academic year, I taught between 8 and 1O interventions with a class of 1st cycle of education, 1st grade, and with a class of 2nd cycle of education, a 5th grade.