226 research outputs found

    Environmental education in secondary schools in the region of RibeirĂŁo Preto (SP, Brazil): how teachers' views of the environment determine their teaching and some reflections on chemistry teachers' higher education

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    During short courses, 95 secondary school teachers from 49 state schools and 421 students from the RibeirĂŁo Preto region (in Sao Paulo state, Brazil, with a population of 530,000) were asked to fill in different questionnaires. The points raised in the teacher's questionnaire were used as a guide to establish a continuous dialogue during the short courses. Most of the schools claimed to have some kind of environmental education (EE). Based on the questionnaires and dialogues we analyzed how the teachers' perceptions on EE reflect on the views secondary students hold about their own responsibility for preserving the environment. The role of universities in the preparation of chemistry teachers capable of effectively approaching EE is also discussed

    Modified electrodes prepared with polyphenolic film containing ruthenium complex and metal ligand anchored by azo covalent bond

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    This work presents two new modified carbon electrodes which were prepared via the polymerization of a phenolic moiety previously functionalized with azo groups (bipyridine and 2-methoxypyridine) as key structures to anchor the desired ligands. The syntheses of BAP (4-([2,2’]-bipyridinyl-4-ylazo)-phenol) and PAPmethoxy (5-(4-hidroxyphenylazo) pyridin-2-methoxy) were simple to perform, gave good yields and the monomers were easily electropolymerized resulting in chemically and mechanically stable modified electrodes. The PAP-methoxy ME formed stable complexes with Cd, Cu and Pb in aqueous media at open circuit and produced well defined redox peaks, showing good potential for future analytical applications. The BAP monomer was used to produce a ruthenium complex (BAP-Ru) which was electropolymerized from +0.50 to +0.75V (vs. Ag/AgCl) to leave the ruthenium available to act as a catalyst. The BAP-Ru ME was able to oxidize a variety of organic substrates with good selectivity. The yields obtained were either similar to, or better than, those obtained by homogeneous catalysis using a similar ruthenium catalyst or when this type of catalyst is supported in a carbon paste electrode.Este trabalho apresenta dois novos eletrodos de grafite modificados que foram preparados via polimerização da função fenĂłlica, previamente funcionalizada por grupos azo (bipiridina e 2-metoxipiridina), que atuam como estruturas chaves para a ancoragem de ligantes de interesse. As sĂ­nteses dos monĂŽmeros BAP (4-([2,2’]bipiridinil-4-ilazo)-fenol) e PAPmetĂłxi (5-(4-hidroxifenilazo)piridin-2-metĂłxi) foram simples, deram bons rendimentos e os monĂŽmeros foram facilmente eletropolimerizados, levando Ă  formação de eletrodos modificados (EM) quĂ­mica e mecanicamente estĂĄveis. Em solução aquosa e em circuito aberto, o EM PAP-metĂłxi formou complexos estĂĄveis com Cd, Cu e Pb, produzindo picos redox bem definidos, demonstrando o grande potencial deste eletrodo para futuras aplicaçÔes analĂ­ticas. O monĂŽmero BAP foi utilizado para produzir um complexo de rutĂȘnio (BAP-Ru) que foi eletropolimerizado entre +0.50 e +0.75V (vs. Ag/AgCl), permitindo que o rutĂȘnio permanecesse disponĂ­vel para atuar como catalisador. O EM BAP-Ru oxidou seletivamente uma variedade de substratos orgĂąnicos dando produtos com rendimentos prĂłximos ou melhores que aqueles obtidos por catĂĄlise homogĂȘnea com complexos de rutĂȘnio similares, ou quando este tipo de catalisador Ă© impregnado em pasta de carbono.CNPqCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES

    An overview of how the curricula taken by future chemistry teachers in southeastern Brazil's public universities approach environmental issues

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    This work analysed the contents of 701 disciplines from 22 chemistry courses that prepare chemistry teachers in 16 public Universities in Southeastern Brazil. Only a small number (23) of disciplines showed an explicit relationship between human activities and the environment. A total of 11 theoretical and 193 experimental disciplines explored to some extent scientific and technological aspects related to the environment, but did not include their relationship with society. As the experimental disciplines supposedly include some kind of waste treatment, this may explain why secondary school chemistry teachers work mainly on recycling programs and waste issues at their schools. The aim of this work is to provide information on which to base a much needed discussion about how to better prepare our chemistry teachers to act as Environmental Educators at school, as the Brazilian Education Legislation requires

    Pesquisa de Staphylococcus aureus enterotoxigĂȘnico nas fossas nasais de manipuladores de alimentos em hospitais, SĂŁo Paulo, 1976

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    The presence of enterotoxic S. aureus in the nasal fossae of hospital food handlers was investigated. Material was collected from the anterior portion of fossae of 34 food handlers in the kitchens of three hospitals in the city of S. Paulo, Brazil. Of these 34 persons, 12 (35.3%) were positive for S. aureus, of these same 12, two (16.7%) showed positive for type C staphylococcal enterotoxin producing strains. Of the 12 strains isolated, nine (75%) could be phagetyped; of the enterotoxic strains, one was lysed by Group III phage; the other was non-typeable.Foi realizada a verificação da presença de Staphylococcus aureus enterotoxigĂȘnico, em manipuladores de alimentos, em cozinhas hospitalares. Foi colhido material da porção anterior das fossas nasais de 34 pessoas que trabalhavam em trĂȘs hospitais da cidade de SĂŁo Paulo. Dentre os indivĂ­duos examinados, 12 (35,3%) revelaram-se portadores de S. aureus e, destes 2 (16,7%) foram positivos para cepas produtoras de enterotoxina estafilocĂłcica do tipo C. Das 12 cepas isoladas, 9 (75%) foram fagotipĂĄveis; das duas cepas enterotoxigĂȘnicas, uma foi nĂŁo fagotipĂĄvel e a outra foi Usada por fagos do grupo III

    Educação, currículo escolar e protagonismo juvenil: os desafios da educação na contemporaneidade

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    Resumo: Este artigo se insere no debate sobre educação e polĂ­tica, abordando a relação entre educação, currĂ­culo escolar e violĂȘncia simbĂłlica na perspectiva de adolescentes entre 12 e 17 anos que cumprem medidas socioeducativas no CREAS (Centro de ReferĂȘncia Especializada da AssistĂȘncia Social) de VitĂłria, Brasil. AtravĂ©s de nossas anĂĄlises, percebemos que a educação apresenta desafios, contradiçÔes e tensĂ”es decorrentes principalmente da organização da sociedade contemporĂąnea, que acaba por reforçar a exclusĂŁo desses alunos. AlĂ©m disso, apontamos a discrepĂąncia entre a regulamentação dessas medidas e o cotidiano escolar bem como a falta de protagonismo dos sujeitos envolvidos no cumprimento dessas medidas como alguns obstĂĄculos do processo de inclusĂŁo desses adolescentes. Palavras-chave: Educação; CurrĂ­culo Escolar; Protagonismo Juvenil e ViolĂȘncia.   Resumen: Este artĂ­culo se inserta en el debate sobre educaciĂłn y polĂ­tica, con un enfoque en la relaciĂłn entre educaciĂłn, plan de estudios y violencia simbĂłlica en la perspectiva del adolescente entre 12 y 17 años que cumple una “medida socioeducativa” en el CREAS (Centro de ReferĂȘncia Especializado de la Asistencia Social) de VitĂłria, Brasil. Mediante nuestros anĂĄlisis percibimos que la educaciĂłn presenta desafĂ­os, contradicciones y tensiones derivadas principalmente de la organizaciĂłn de la sociedad contemporĂĄnea, que refuerza la exclusiĂłn. AdemĂĄs, señalamos la discrepancia entre la regulaciĂłn de la medida, y el cotidiano escolar, asĂ­ como la falta de protagonismo de los sujetos involucrados en el cumplimiento de las medidas como algunos obstĂĄculos del proceso de inclusiĂłn de estos adolescentes. Palabras clave: EducaciĂłn; Plan de Estudios; Protagonismo Juvenil y Violencia.   Abstract: The theme of this article is inserted in the debate on education and politics in a way that relates education, curriculum and symbolic violence in the perspective of adolescents at the age range of 12 to 17 years who are under socio-educational measures in the CREAS (Specialized Center of Reference in Social Work) of Vitoria, Brazil. Throughout some analysis we realized that education presents challenges, contradictions and tensions mainly due to the organization of contemporary society, which reinforces exclusion. In addition, we identified the discrepancy between the regulation of these measures and the school routine, and the lack of leadership of the individuals complying with the measures as some of the obstacles these adolescents face in the social inclusion process. Keywords: Education; School Curriculum; Youth Participation and Violence

    Purification and characterization of a collagenase from Penicillium sp. UCP 1286 by polyethylene glycol-phosphate aqueous two-phase system

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    Collagenases are proteolytic enzymes capable of degrading both native and denatured collagen, reported to be applied in industrial, medical and biotechnological sectors. Liquid-liquid extraction using aqueous two-phase system (ATPS) is one of the most promising bioseparation techniques, which can substitute difficult solid-liquid separation processes, offering many advantages over conventional methods including low-processing time, low-cost material and low-energy consumption. The collagenase produced by Penicillium sp. UCP 1286 showed a stronger affinity for the bottom salt-rich phase, where the highest levels of collagenolytic activity were observed at the center point runs, using 15.0% (w/w) PEG 3350 g/mol and 12.5% (w/w) phosphate salt at pH 7.0 and concentration. The enzyme was characterized by thermal stability, pH tolerance and effect of inhibitors, showing optimal collagenolytic activity at 37 °C and pH 9.0 and proved to be a serine protease. ATPS showed high efficiency in the collagenase purification, confirmed by a single band in SDS/PAGE, and can in fact be applied as a quick and inexpensive alternative method.This work was supported by the National Council of Technological and Scientific Development (CNPq) and Coordination for the Improvement of Higher Education Personnel (CAPES). Sara Silvério also acknowledges her post-doc grant (SFRH/BPD/88584/2012) from FCT (SFRH/BPD/88584/2012) (Portuguese Science and Technology Foundation), Portugal

    Seroconversion in asymptomatic COVID-19 pediatric patients with rheumatic diseases of one tertiary referral hospital

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    Objectives: To evaluate seroconverted asymptomatic COVID-19 in pediatric Autoimmune Rheumatic Diseases (ARDs) patients and to identify the risk factors related to contagion. Methods: A cross-sectional study was conducted in March 2021, before vaccination of children and adolescents in Brazil, including 77 pediatric ARDs patients, followed at a tertiary hospital and 45 healthy controls, all of them without a previous diagnosis of COVID-19. Data was obtained by a questionnaire with demographic data, symptoms compatible with COVID-19 over the previous year, and contact with people with confirmed COVID-19. Patient's medical records were reviewed to access data regarding disease and current medications. A qualitative immunochromatographic SARS-CoV-2 test was performed on all participants. Results: Patients and controls were similar in terms of female gender (70.1% vs. 57.8%, p = 0.173), age (14 vs. 13 years, p = 0.269) and SARS-CoV-2 positive serology (22% vs. 15.5%, p = 0.481). 80.5% of rheumatic patients were in use of immunosuppressive drugs: 27.3% of them used corticosteroids (33.3% in high doses), and 7.8% on immunobiologicals. No statistical differences were found between positive (n = 17) and negative serology (n = 60) patients regarding demographic/socioeconomic data, contact with people with confirmed COVID-19, use and number of immunosuppressive drugs, use and dose of corticosteroids, use of hydroxychloroquine and immunobiological drugs (p > 0.05). Conclusions: Pediatric rheumatic disease patients were infected at the same rate as healthy ones. Neither the underlying pathology nor its immunosuppressive treatment seemed to interfere with contagion risk

    Antibacterial activity of a new monocarbonyl analog of curcumin MAC 4 is associated with divisome disruption

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    Curcumin (CUR) is a symmetrical dicarbonyl compound with antibacterial activity. On the other hand, pharmacokinetic and chemical stability limitations hinder its therapeutic application. Monocarbonyl analogs of curcumin (MACs) have been shown to overcome these barriers. We synthesized and investigated the antibacterial activity of a series of unsymmetrical MACs derived from acetone against Mycobacterium tuberculosis and Gram-negative and Gram-positive species. Phenolic MACs 4, 6 and 8 showed a broad spectrum and potent activity, mainly against M. tuberculosis, Acinetobacter baumannii and methicillin-resistant Staphylococcus aureus (MRSA), with MIC (minimum inhibitory concentration) values ranging from 0.9 to 15.6 ”g/mL. The investigation regarding toxicity on human lung cells (MRC-5 and A549 lines) revealed MAC 4 was more selective than MACs 6 and 8, with SI (selectivity index) values ranging from 5.4 to 15.6. In addition, MAC 4 did not demonstrate genotoxic effects on A549 cells and it was more stable than CUR in phosphate buffer (pH 7.4) for 24 h at 37 °C. Fluorescence and phase contrast microscopies indicated that MAC 4 has the ability to disrupt the divisome of Bacillus subtilis without damaging its cytoplasmic membrane. However, biochemical investigations demonstrated that MAC 4 did not affect the GTPase activity of B. subtilis FtsZ, which is the main constituent of the bacterial divisome. These results corroborated that MAC 4 is a promising antitubercular and antibacterial agent
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