Análise da indexação da Biblioteca Setorial de Química da Universidade Federal do Rio Grande do Norte através de um estudo informétrico

Analisa a indexação dos documentos da Biblioteca Setorial de Química através de um estudo informétrico na ferramenta de busca do Sistema de Bibliotecas (SISBI) da Universidade Federal do Rio Grande do Norte (UFRN). Descreve um estudo informétrico realizado na ferramenta de busca do SISBI da UFRN, sendo feita direcionada para os documentos Biblioteca Setorial de Química. Enfoca a importância do estudo informétrico para analisar a recuperação da informação relacionada à indexação. Aborda a relação da informetria com a indexação e recuperação da informação com o intuito de que o profissional bibliotecário seja mais analítico e tenha uma compreensão maior do campo da ciência da informação. Utiliza de uma metodologia de consultas de assuntos pré-definidos, sendo feita uma filtragem de forma quantitativa com o objetivo de verificar se a indexação dos documentos está sendo satisfatória para a recuperação da informação na ferramenta de busca do SISBI. Constata a relevância dos documentos em cada busca sua precisão e revocação, mostrando que para haver uma boa recuperação da informação tem que a indexação seja feita de forma que não haja ambiguidade com outros termos, com isso mostra a importância de sempre ser feito um estudo informétrico com que verifique a recuperação da informação para que possa sempre haver uma melhora na mesma.

Demanda química de oxigênio, clorofila a e comunidade fitoplanctônica como indicadores da qualidade da água no Canal do Pataxó/RN

The current study examined spatial-temporal modifications and water quality through chemical and biotic indicators during both dry (January, February and November 2006) and wet seasons (March to June 2006). This study was carried out in Armando Ribeiro Gonçalves Reservoir, RN, Canal do Pataxó and after the water station treatment (WST). The physical-chemical parameters were measured in situ and inorganic nutrients, chlorophyll a and Free Oxygen Demand (FOD) were analyzed in laboratory conditions. Quali quantitative analyses of phytoplankton were carried out utilizing Sedgwick-Rafter camera. Results indicate that DQO concentrations were low. FOD concentrations in the reservoir were comparatively higher in the dry season (5.21 mgL-1; 5.64 mgL-1 e 6.05 mgL-1) in relation to the wet season (4.52 mgL-1; 4.12 mgL-1 e 4.92 mgL-1), in surface, intermediate and bottom waters, respectively. FOD values were inferior to 1.0mgL-1in both Canal do Pataxó and after WST, which is considered adequate for public use reservoirs. Although FOD concentrations were low, Armando Ribeiro Gonçalves Reservoir, Canal do Pataxó and WST were classified as euthophizied, mesotrophic ad oligotrophic, respectively, considering the Index of Trophic State Criteria. Chlorophyll a concentrations in the study reservoir were higher in the surface (199.2 µgL-1) during the wet season, whereas in Canal do Pataxó concentrations decreased from 1.56 µgL-1 to 0.028 µgL-1, and after WST values were low (0.059 µgL-1). Dominance of cianobacterias, such as Planktotrhix agardhii (dry season) and Microcystis sp (wet season) was registered in all three areas. In the reservoir and Canal do Pataxó, density of cianobacterias, such as P. agardhii and Microcistys sp., was superior to the values allowed by the Health ministry (HM). However, after WST, density values of cianobacteria were inferior to values established by the HM

Caracterização físico-química e efeitos de frações polissacarídicas da alga amansia multifida na coagulação, inflamação, radicais livres e viabilidade celular

Galactans are polysaccharides sulfated present in the cell wall of red algae. Carrageenans are galactans well known in the food industry as gelling polysaccharides and for induce inflammatory process in rodents as animal model. The extraction of polysaccharides from A. multifida has been carried out by proteolysis and precipitation in different volumes of acetone, which produced three fractions (F1, F2, and FT). Chemical and physical analyses revealed that these fractions are sulfated galactan predominantly. Results of the antioxidant activity assays showed that all of these fractions have antioxidant activity and that was associated with sulfate content of the analysis of reducing power and total antioxidant capacity. However, these fractions were not effective against lipid peroxidation. The fraction FT presented higher activity on the APTT test at 200 μg (> 240 s). The assessment of the hemolytic activity showed that the FT fraction has the best activity, increasing lyses by the complement system to 42.3% (50 μg) (p< 0,001). The fraction FT showed the best yield, anticoagulant and hemolytic activity between the three fractions and therefore it was choose for the in vivo studies. The Inflammation assessment using the FT fraction (50 mg / kg MB) showed that the cellular migration and the IL-6 production increased 670.1% (p< 0,001) and 531.8% (p< 0,001), respectively. These results confirmed its use as an inflammation inducer in animal model. Cytotoxicity assay results showed that all fractions have toxic effects on 3T3 and HeLa cells after exposition of 48 hours, except when 100 μg for both F1 and FT were used. These results arise the discussion whether these polysaccharides it should be used as additive in foods, cosmetics and medicines.

Caracterização físico-química e ações farmacológicas hepatoprotetora, antiinflamatória, pró-angiogênica, antioxidante e anticoagulante da fração rica em fucana 0,8FRF 0,8 da alga marrom Lobophora variegata

This study examines the physical and chemical composition and the pharmacological effects of brown seaweed FRF 0.8 Lobophora variegata. Fractionation of the crude extract was done with the concentration of 0.8 volumes of acetone, obtaining the FRF 0.8. The physicochemical characterization showed that it was a fucana sulfated. Anti-inflammatory activity was assessed by paw edema model by the high rates of inhibition of the edema and the best results were in the fourth hour after induction (100 ± 1.4% at the dose of 75 mg / kg) and by the strong inhibitory activity of the enzyme myeloperoxidase (91.45% at the dose of 25 mg / kg). The hepataproteção was demonstrated by measurements of enzymatic and metabolic parameters indicative of liver damage, such as bilirubin (reduction in 68.81%, 70.68% and 68.21% for bilirubin total, direct and indirect, respectively at a dose of 75 mg / kg), ALT, AST and γ-GT (decrease of 76.93%, 44.58% and 50% respectively at a dose of 75 mg / kg) by analysis of histological slides of liver tissue, confirming that hepatoprotective effect the polymers of carbohydrates, showing a reduction in tissue damage caused by CCl4 and the inhibition of the enzyme complex of cytochrome P 450 (increasing sleep time in 54.6% and reducing the latency time in 71.43%). The effectiveness of the FRF 0.8 angiogenesis was examined in chorioallantoic membrane (CAM) of fertilized eggs, with the density of capillaries evaluated and scored, showing an effect proangigênico at all concentrations tested FRF (10 mg- 1000 mg). The FRF showed antioxidant activity on free radicals (by inhibiting Superoxide Radical in 55.62 ± 2.10%, Lipid Peroxidation in 100.15 ± 0.01%, Hydroxyl Radical in 41.84 ± 0.001% and 71.47 Peroxide in ± 2.69% at concentration of 0.62 mg / mL). The anticoagulant activity was observed with prolongation of activated partial thromboplastin time (aPTT) at 50 mg (> 240 s), showing that its action occurs in the intrinsic pathway of the coagulation cascade. Thus, our results indicate that these sulfated polysaccharides are an important pharmacological target

Produção de biomassa e composição química de adubos verdes cultivados no Vale do Ribeira

The contribution of green manure to soil improvement and crop production depends primarily on biomass production and its chemical composition, which vary depending on the species, region and growing season. The aim of this research was to evaluate the chemical composition of biomass produced by green manures in Vale do Ribeira, São Paulo, Brazil. In order to develop this research, was carried an experiment in Pariquera-Acu, in 2006/2007, in completely randomized blocks design with four treatments (three green manure and spontaneous vegetation) and five replications. At 30, 60, 90 and 120 after sowing samples were collected in 1m(2) of the shoots and determined fresh and dry, and chemical composition biomass. Sunhemp, pigeon pea and mucuna produced, in decreasing order, the largest quantities of biomass and were more efficient than the spontaneous vegetation. The biomass produced by green manure had higher quality than that produced by spontaneous vegetation. Sunhemp and pigeon pea have a higher proportion of dry matter in stems which have low N, high C/N and L/N ratio, variables indicating slow decomposition of residues. The analysis of dry matter partitioned to better indication of the chemical composition of the residues and the prevision of the availability of nutrients in the soil.

Aditivos químicos e biológicos na ensilagem de cana-de-açúcar: 1. composição química das silagens, ingestão, digestibilidade e comportamento ingestivo

Avaliou-se o efeito da inclusão de aditivos na ensilagem de cana-de-açúcar (Saccharum officinarum L.) sobre a composição químico-bromatológica das silagens, o comportamento ingestivo, o consumo voluntário e a digestibilidade em bovinos de corte. Utilizaram-se cinco novilhos da raça Nelore providos de cânula ruminal, alocados em delineamento quadrado latino 5 ´ 5 e alimentados com dietas com 65% de volumoso na MS. Foram avaliadas cinco silagens (base úmida): controle - cana-de-açúcar sem aditivos; uréia - cana-de-açúcar + 0,5% uréia; benzoato - cana-de-açúcar + 0,1% de benzoato de sódio; LP - cana-de-açúcar inoculada com Lactobacillus plantarum (1 ´ 10(6) ufc/g MV); LB - cana-de-açúcar inoculada com L. buchneri (3,6 ´ 10(5) ufc/g forragem). A forragem foi armazenada em silos do tipo poço por 90 dias antes do fornecimento aos animais. A composição químico-bromatológica da cana-de-açúcar foi alterada após a ensilagem, em relação à cana-de-açúcar original, com redução no teor de carboidratos solúveis e na digestibilidade in vitro e elevação relativa nos teores de FDN e FDA. Os teores de etanol (0,30% da MS) e ácidos orgânicos (0,99% de ácido lático e 2,31% de acético) foram baixos e semelhantes entre as silagens. Os aditivos aplicados na ensilagem não promoveram alterações no consumo e na digestibilidade aparente da MS (7,2 kg/dia e 63,6%, respectivamente). O comportamento ingestivo dos animais também não foi alterado, com tempos médios de 230,6; 519,6 e 672,8 minutos/dia despendidos com ingestão de ração, ruminação e ócio, respectivamente. Os aditivos acrescidos à cana-de-açúcar promoveram pequenas alterações na maioria das variáveis avaliadas.

Caracterização físico-química de complexo de inclusão entre hidroximetilnitrofurazona e hidroxipropil-beta-ciclodextrina

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A intermediação da noção de probabilidade na construção de conceitos relacionados à cinética química

Este trabalho procurou identificar como estudantes do Ensino Médio se apropriam de conceitos e elaboram determinados modelos inseridos em cinética química, especificamente o modelo cinético de colisão de partículas numa reação (Teoria das Colisões). Esta análise e as reflexões que a seguiram foram baseadas, sobretudo, nos estudos realizados por Piaget, Piaget e Inhelder, Jun e Fischbein. Utilizamos como documentos as transcrições das entrevistas (pré e pós-testes) realizadas individualmente com cada aluno. Inicialmente, os estudantes foram entrevistados (pré-testes) com o intuito de identificar a familiaridade com a noção de evento probabilístico ou aleatório. Numa segunda etapa (pós-testes), esse conhecimento (ou a ausência parcial/total dele) foi posto à prova numa tentativa de se estabelecerem relações com um conteúdo específico da Química (Teoria das Colisões). Os resultados obtidos apontam para grandes discrepâncias entre o modelo cinético de colisões elaborado pelos estudantes e aquele cientificamente aceito.

Avaliação da composição química, atividade antioxidante, antibacteriana, antinoceptiva, antiinflamatória e toxicidade do extrato metanólico e frações de folhas de Spondias sp. (Anacardiaceae)

Spondias sp. (Anacardiaceae), popularly known as cajá-umbu, is an endemic plant from Northeastern Brazil, where their leaves are widely used in folk medicine to treat inflammatory processes, while their fruits have a great agro industrial potential. This study was designed to evaluate hepatoprotective, antinociceptive, antioxidant, antimicrobial and anti-inflammatory properties, as well as the acute toxicity and repeated dose 28, using a methanolic extract (MES), a fraction rich in flavonoids (FRF) and a precipitate from Spondias sp.leaves. The antioxidant activity of them was valued to evaluate their free radical scavenger capacity by DPPH test, whereas MES and FRF were used to evaluate while the preventive action on carbon tetrachloride (CCl4)-induced hepatotoxicity. Seven groups (n=5) of female Wistar rats were used as follows: control group, CCl4-intoxicated group treated with EMS (500 mg/kg) for 7 days, three CCl4-intoxicated groups treated with FRF (25, 50 and 75 mg/kg) for 7 days and the CCl4-intoxicated group treated with Legalon ® (silimarina; (phytotherapeutic reference) (50 mg/kg; 7 days). MES and FRF showed a protective action against liver injury induced by CCl4, being observed a significant reduction of serum enzyme activity marker of liver damage (alanine transaminase and aspartate transaminase). On the other hand, the lipid peroxidation (SRAT) decrease, as well as the increase of glutathione content and enzyme activity of antioxidant defense system (SOD, CAT, GPx) toward near normal values indicated the ability of EMS to restore the oxidative imbalance induced by CCl4. The histological analysis confirmed the hepatoprotection, compared to degenerative changes in CCl4-treated group. This hepatoprotetor effect was similar to that shown by Legalon®. The in vitro high antioxidant capacity of extract (93.16 ± 1.00%) showed analogous results to those obtained by Carduus marianus BHT (reference standard). This fact explains the obtained results in vivo. Although no antimicrobial activity was detected, EMS and FRF promoted the antinociceptive effect induced in the second phase by the intraplantar formalin test, evidencing the anti-inflammatory action; confirmed by the carrageenan-induced peritonitis model. The evaluation of the mechanical allodynia (CFA a 80%) demonstrated the involvement of the Spondias sp. chemical composition in the anti-inflammatory activity toward the acute processes. The acute exposure and repeated dose during 28 days did not produce significant changes in the parameters that evaluate toxicity. Together the experimental results reveal, that Spondias sp. leaf extracts have a promising potential in pharmaceutical area, and due to its non-toxic condition present efficiency and security

Caracterização físico-química de frutos de maracujazeiro-amarelo submetidos à iluminação artificial, irrigação e sombreamento

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

O uso de modelos no ensino de química: uma investigação acerca dos saberes construídos durante a formação inicial de professores de Química da UFRN

In the past twenty years, there has been a significant increase of researches about teacher s professionalization. In that context, the investigations concerning teacher s knowledge represent an important contribution, as they aim to identify and to rescue the base of knowledge that sustains the teacher s profession. In particular, the reflections and propositions of Lee Shulman have been constitute a fundamental subsidy to the teacher s professionalization in the sense of harnessing the pedagogic knowledge to the content s knowledge, establishing the pedagogic knowledge of the content that characterizes and differentiates the teacher and the bachelor in a certain field of knowledge. Among the indispensable knowledge for the Chemistry teacher's professional practice, in this research we have pointed out the pertinence of the knowledge on the use of models in Chemistry classes in the middle and high school. Those knowledges regard the comprehension of students concerning the understanding and models elaborated in science and the models implemented in the Chemistry teaching, as well as the abilities to plan didactic situations that use models. In this research, we aimed to identify the contributions and barriers during the Chemistry teacher education, in UFRN, in relation to the construction of knowledge that subsidize training teachers in the elaboration of teaching activities that involve the use of models. The investigation was accomplished in UFRN, in the Course of Degree in Chemistry, along with 13 student teachers that studied the subject Practice of Chemistry Teaching. For this research, the following instruments were used: questionnaires with open and closed questions, elaboration of a plan of activities for the Chemistry teaching and an interview to answer the established study s questions. The data was analyzed in an established criteria, classified and tabled. The results showed that the student teachers representations regarding scientific knowledge contemplated, among other topics, the idea of a method for his/her construction. In some cases, the models role was emphasized in that construction, as well as the social dimension in the validation of that knowledge. The scientific models were highlighted by most of the student teachers, as a representation method to explain, understand and interpret the chemical phenomena. On the other hand, the didactic models stood out, in most of cases, as a method of aiding the Chemistry students of the Basic Education to understand the scientific models. The representations regarding those categories contemplated important aspects, although in a superficial way, reflecting the limitations of reflections during the formative process. In the elaboration of teaching activities that use models, difficulties were evidenced, in the process of plan construction, relative to the didactic structure and to the proposition of activities that contemplated models, although the student teachers have mobilized different elements regarding the pedagogic knowledge of the content. Such verifications evidence the urge for the teacher development programs to promote changes in the teacher education in order to propitiate, during this process, reflections, discussions and propositions of activities regarding categories highlighted in this research, contributing to the construction of initial elements regarding the pedagogic knowledge of the content that will be developed throughout teaching, therefore corroborating to the teacher s professionalization

Períodos de matocompetição na cultura da soja (Glycine max (L.) Merril), cultivares Santa Rosa e IAC-2: II - Efeitos sobre características morfológicas das plantas e constituição química dos grãos

Foram, conduzidos experimentos de campo com os cultivares Santa Rosa e IAC-2 em dois tipos de solos, Latossol Roxo e Latossol Vermelho Escuro - fase arenosa, no Município, de Jaboticabal (SP), com o objetivo de estudar a influência do período de competição das plantas daninhas sobre algumas características morfológicas relacionadas à produção e composição química dos grãos, na cultura da soja. O delineamento experimental utilizado foi o de blocos ao acaso, sendo os cultivares mantidos sem e com matocompetição por períodos cujas extensões foram 0, 10, 20, 30, 40, 50 e 60 dias após a emergência. Com base nos resultados obtidos, pode-se chegar à conclusão que um período inicial curto (20 a 30 dias) livre da matocompetição, foi suficiente para que não ocorressem efeitos negativos, estatisticamente significativos, na altura final das plantas, no diâmetro do caule e na altura de inserção da vagem mais baixa, além de ser suficiente para que os teores de proteína, extrato-etéreo e cinzas, dos grãos, se mantivessem dentro dos valores normais esperados para os dois cultivares, nos solos estudados.

Aplicação, em pré-colheita, de dessecante em duas cultivares de soja (Glycine max (L. ) Merril) III - Efeitos sobre a composição química (proteína, óleo e cinzas) e resíduos nas sementes

A aplicação pré-colheita do dessecante paraquat, quando real izada a partir das primeiras épocas (75 e 72 dias após o início do florescimento, para a Santa Rosa e IAC-2, respectivamente) não modificaram os teores com que ocorreram normalmente, proteína, extrato etéreo e cinzas nos grãos. As análises do resíduo de paraquat nos grãos colhidos, mostram claramente que não se deve recomendar tal prática às lavouras de soja, cujo objetivo final seja o fornecimento de grãos para a alimentação humana e animal. Entretanto pode ser indicada, sem maiores restrições, àquelas cuja finalidade é a produção de sementes comerciais.

Processamento mínimo em goiabas 'Paluma' e 'Pedro Sato': 2. Avaliação química, sensorial e microbiológica

Foram utilizados frutos de goiabeiras das cultivares Pedro Sato e Paluma, provenientes de pomar comercial, no estádio de maturação de vez, correspondente à coloração verde-mate e considerados ótimo para o consumo. Os frutos foram inicialmente imersos em solução de hipoclorito de sódio (150mg de cloro.L-1) por 5 minutos, para desinfecção superficial. Pessoas treinadas, utilizando proteção adequada e equipamentos desinfetados descascaram os frutos, cortaram-nos longitudinalmente ao meio e eliminaram a polpa com as sementes, em ambiente a 12°C. Após enxágüe com água clorada (20mg de cloro.L-1) foram embalados em contentores de tereftalato de polietileno (PET) com tampa. Estas unidades foram armazenadas a 3°C por 10 dias. Foram realizadas análises microbiológicas ao longo do período. Determinaram-se quimicamente os conteúdos de lignina, ácido ascórbico, acidez total titulável, sólidos solúveis totais e porcentagem de solubilização das pectinas, bem como as variáveis sensoriais de textura, sabor e preferência. A textura tornou-se mais frágil e os conteúdos de ácido ascórbico se reduziram, ao longo do período de armazenamento, nos produtos de ambas as cultivares. Durante este período houve aumento no conteúdo de lignina e manutenção dos conteúdos de sólidos solúveis totais (SST), acidez total titulável (ATT) e da relação SST/ATT. O produto da cultivar Pedro Sato apresentou menor perda de textura que o da 'Paluma', sendo considerado pelos provadores como o mais saboroso e, portanto, o mais preferido. Devido aos cuidados higiênicos tomados durante o processamento o produto apresentou baixa contagem microbiana (< 10³ UFC.g-1), em todas as avaliações efetuadas.

Como vão se formando os professores em física e química: embates entre o ser, o ter e o fazer na formação de licenciandos da UFRN sob a perspectiva da teoria das representações sociais

The purpose of this work is to approach and understand the Social Representations (SR) (MOSCOVICI, 2003) about Physics and Chemistry from people who are major in these courses, as well as their Social Representations about teaching . We took as principle that approaching these representations it would be possible to relate their symbolic contents, in order to show how people who are following the first segments of bachelor degree courses in Physics and Chemistry become teachers, taking into account a psychosocial view. Two source of data was used during this research: Free-association Technique FA (ABRIC, 1994); and Multiple Classification Procedure (MCP) (ROAZZI, 1995). The analytical treatment of the collected data from FA was done according to the proposition of Grize, Vergés and Silem (1987 apud ABRIC, 1994, p. 66). MCP data were analyzed through MSA (Multidimensional Scalogram Analysis) and SSA (Singular Spectrum Analysis) methods associated with the Facet Theory (BILSKY, 2003). The discourses of MCP discussing groups at the moment of explanations were studied by Content Analysis as it was proposed by Bardin (1977) and Franco (2005). Indicative of an approach to the relations with knowledge (CHARLOT, 2000), the connections which aroused from the analyses showed that the group of future majors in Physics thought that this scientific field was based on a rationalist conception, influencing the idealization sense of the phenomena to be explained by Physics. Thus, Physics as school content started to require the student of the fundamental and high school to think abstractly as a cognitive skill of learning. The identifying elements observed in the relations between SR about Physics and Teaching aroused from the antagonism between future majors and their teacher, as well as from the speculation between their fundamental and high school students and themselves, mainly when they had to face the act of teaching due to the obstacles imposed by the own educational system, and by the weakness of the initial preparation. The group of future majors in Chemistry, through its discourses, showed these relations when they conceived empiricist Chemistry and said that teaching was the way of transmission of this knowledge, and didactics of Chemistry teaching was the direction to learning through pedagogic methods in order to lead the students to discoveries. The psychosocial contents which were built and showed from the symbolic relations in the studied SR achieved the relation of identity. This relation revealed identifying elements for these people, resulting from the traffic between their condition as students of Chemistry, and as teachers regarding their work, what placed the current relational contents in the teaching space, named as Knowledge changing and Adaptability . In order to study emerging questions in the discussing environment about formation and teaching professionalization, we focused the psychosocial view on this traffic and managed to observe epistemological practical and pedagogic obstacles that limited a configuration of the teaching work as a professional activity, especially from the particular conditions which led the relations of senses to Physics , Chemistry and Teaching ; and Chemistry and Physics as it was seen in this research. Generally speaking, we noted that these obstacles can denounce such obstacles concerning to the pedagogic doings which mainly impair the learning process of fundamental and high school students