3,171 research outputs found

    Potencial alelopático e identificação de compostos secundários em extratos de calopogônio (Calopogonium mucunoides) utilizando eletroforese capilar

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    In this paper we describe the assessment of the possible allelopathic potential of organic extracts obtained from leaves of Calopogonium mucunoides under laboratory conditions, after that some secondary compounds were identified and quantified using capillary electrophoresis. After the identification and quantification of the compounds, we studied the effects of these compounds on the germination of some common weed, which are actually becoming a real problem in pastures in the state of Pará - Brazil. Calopogônio presented allelopathic potential. The organic crude extracts obtained from solvents with high dielectric constants (dichloromethane and ethyl acetate) were the most efficient in the inhibition of the weed germination. Seeds of Mimosa pudica were more affected by the extracts; this fact reveals the specificity of the organic extracts obtained. Capillary electrophoresis protocols were highly specific, which makes it possible to identify 5 classes of compounds using the same crude extract samples and analyze them fartly (up to 20min). Many of identified compounds show inhibitory effect in the weeds germination, seeds of malicia were the most sensible, the bioassays with the misture of compounds indicated the possibility of synergic effect.Neste trabalho avaliou-se o potencial alelopático de extratos orgânicos obtidos a partir das folhas de Calopogonium mucunoides sobre a germinação de sementes de algumas plantas daninhas comumente encontradas em áreas de pastagens cultivadas da Amazônia brasileira, as quais causam grandes danos à produtividade: Cassia tora (mata-pasto), Mimosa pudica (malícia) e Cassia occidentalis (fedegoso). Compostos secundários foram identificados e quantificados nos extratos brutos utilizando eletroforese capilar. Após identificar e quantificar os compostos presentes nos extratos realizaram-se novos bioensaios com os padrões dos compostos identificados a fim de verificar se os mesmos poderiam atuar como inibidores na germinação das sementes das plantas daninhas em estudo. Calopogonium mucunoides apresentou potencial alelopático o qual variou com a espécie de planta daninha estudada. Os protocolos desenvolvidos utilizando eletroforese capilar se mostraram eficientes e bastante específicos, sendo possível a separação e identificação de 5 classes de compostos nos extratos brutos sem necessidade de clean up ou fracionamento dos mesmos, com análises rápidas (em menos de 20 minutos) e baixas quantidades de solventes utilizadas quando comparadas aos métodos tradicionais de análises. Vários dos compostos identificados apresentaram potencial de inibição de germinação nas sementes estudadas, sendo malícia a mais sensível, os bioensaios também indicaram certo efeito sinérgico ao utilizar a mistura de compostos.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Universidade de São Paulo Instituto de Química de São CarlosUniversidade Federal de São Paulo (UNIFESP) Departamento de Ciências Exatas e da TerraEmpresa Brasileira de Pesquisa AgropecuáriaUNIFESP, Depto. de Ciências Exatas e da TerraSciEL

    Aspectos biológicos do ácaro vermelho do tomateiro

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    Some biological aspects of Tetranychus evansi Baker & Pritchard, including the duration of young stages and reproductive capacity, were studied under laboratory conditions, using tomato var. Rossol as host plant. The durations of egg, larva, protonymph and deutonymph stages were of 4.8, 2.6, 2.4 and 3.2 days, respectively, corresponding to a total duration of approximately thirteen days from egg to adult for both saxes. The highest oviposition levels were attained from the fourth to the tenth day, approximately. An average of 105.7 eggs were laid during the whole oviposition period. Probably, the utilization of median or basal instead of apical leaves, as substrate, would have resulted in shorter life cycle and a higher total oviposition than what was obtained in this study.Alguns aspectos biológicos de Tetranychus evansi Baker & Pritchard foram estudados em laboratório, incluindo a duração das formas jovens e a capacidade reprodutiva, em plantas de tomate var. Rossol. As durações dos estágios do ovo, larva, protoninfa e deutoninfa foram de 4,8; 2,6; 2,4 e 3,2 dias, respectivamente, correspondendo a uma duração total de, aproximadamente treze dias de ovo a adulto, para ambos os sexos. Os níveis mais altos de oviposição foram obtidos do quarto ao décimo dia, aproximadamente. Uma média de 105,7 ovos foram postos durante todo o período de oviposição. Provavelmente, a utilização de folhas medianas ou basais, ao invés de apicais, como substrato teria resultado em um ciclo biológico mais curto e em uma oviposição total maior do que os obtidas neste estudo

    Quantificação dos teores de açúcares, oligossacarídeos e amido em genótipos/ cultivares de soja (Glycine Max (L) Merril) especiais utilizados para alimentação humana.

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    RESUMO: Na soja, vários componentes, tais como açúcares, aminoácidos, ácidos orgânicos, sais inorgânicos, isoflavonas e saponinas estão relacionados com o sabor. Os açúcares, a sacarose e o amido, podem melhorar o sabor e a textura da soja. O objetivo deste trabalho foi quantificar os teores desses compostos e dos oligossacarídeos, em sementes de 28 genótipos/cultivares do Banco Ativo de Germoplasma da Embrapa Soja, que apresentam características especiais para o melhoramento genético. Os açúcares e os oligossacarídeos foram quantificados pela técnica de cromatografia liquida de alto desempenho (CLAE) e o amido pela metodologia adaptada de Rickard e Behn (1987). Os genótipos PI 417.159 e F83-8119 apresentaram menores teores de oligossacarídeos totais (2,744 e 3,064 g.100 g de massa seca). As cultivares Tambaguro e Koji Amarela foram as que apresentaram teores de sacarose superiores a 6 g.100 g–1 de massa seca(6,327 e 6,162), enquanto que a única cultivar que apresentou um teor superior a 1 g.100g–1–1 de massa seca de amido foi a Tambaguro (1,191). As cultivares Koji Preta, Tamahomare, Tambaguro e BRS 267 foram estatisticamente superiores quando os 3 atributos (oligossacarídeos totais, sacarose e amido) foram avaliados conjuntamente, com o foco em sabor superior. As cultivares Koji Preta, Tamahomare, Tambaguro foram as melhores fontes genéticas indicadas para cruzamentos, pois não são tropicalizadas, enquanto a cultivar BRS 267 pode melhorar as qualidades sensoriais dos produtos processados a partir de soja. Por outro lado, a cultivar Late Giant, devido ao maior teor de oligossacarídeos, é uma fonte genética em potencial para produção de um alimento funcional à base de soja. ABSTRACT: In soybeans, many components such as sugars, amino acids, organic acids, inorganic salts, saponins and isoflavones are related to the flavour. The sugars, sucrose and starch can improve the soybean flavour and texture. The present study aimed to quantify the contents of these compounds and also the oligosaccharides in the seeds from 28 genotypes/cultivars obtained from the Embrapa Soybean Germplasm Bank, that present special characteristics for genetic improvement programmes. The sugars and oligosaccharides were quantified by high-performance liquid chromatography (HPLC) and the starch by methodology adapted from Rickard e Behn (1987). The genotypes PI 417.159 and F83-8119 showed the lowest contents of total oligosaccharides (2.744 and 3.064 g.100 g DW). The cultivars Tambaguro and Koji Amarela showed sucrose levels above 6 g.100 g–1 DW (6.327 and 6.162), and the only cultivar with a starch content above 1 g.100 g–1 DW was Tambaguro (1.191). The cultivars Koji Preta, Tamahomare, Tambaguro and BRS 267 were statistically better when the 3 attributes (total oligosaccharides, sucrose and starch) were analysed together with a focus on better flavour. The cultivars Koji Preta, Tamahomare, Tambaguro were the best genetic sources for breeding because they have not been tropicalized, whilst the cultivar BRS 267 could improve the sensory qualities of processed soybean-based foods. On the other hand, on account of its higher oligosaccharide content, the cultivar Late Giant is a potential genetic source for the production of functional soybean-based foods

    Application of the Quick Tool Exchange (QTE) System in Building Maintenance

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    Quick Tool Exchange (QTE) acts to reduce losses and failures during the production process and throughput time, contributing to rapid response to market changes. The object of the work is a private school of the Municipality of Porto Velho, capital of Rondônia. The general objective is to study the building maintenance of a private school in the Municipality of Porto Velho / RO, focusing on QTE technology. Therefore, the specific objectives were to characterize the building maintenance in the study (1); compare the operational processes applied in the face of QTE concepts (2); and propose innovation for the operational improvement of building maintenance in operation (3). The building maintenance has a clear importance, since its compliance contributes to the preservation of life and health of users of any construction. Both the preventive and the corrective have been receiving the importance due to it, especially the preventive one, since this is always cheaper in comparison to the corrective one, since besides the damages caused to the physical structure of the building, there can exist to the users present in the occurrence of the fact. The methodological procedures consisted in carrying out a bibliographic survey followed by a case study. The results demonstrated measures approved and not approved by the QTE, suggesting simple innovations, but with significant consequences to the improvement of service rendering, minimizing costs in the area of building maintenance. This study is of interest to businessmen in general, especially the public or private educational sector, and those involved with the area of Production Administration

    Classification of induced magnetic field signals for the microstructural characterization of sigma phase in duplex stainless steels

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    Duplex stainless steels present excellent mechanical and corrosion resistance properties.However, when heat treated at temperatures above 600 ºC, the undesirable tertiary sigma phaseis formed. This phase presents high hardness, around 900 HV, and it is rich in chromium, thematerial toughness being compromised when the amount of this phase is not less than 4%. Thiswork aimed to develop a solution for the detection of this phase in duplex stainless steels throughthe computational classification of induced magnetic field signals. The proposed solution is based onan Optimum Path Forest classifier, which was revealed to be more robust and effective than Bayes,Artificial Neural Network and Support Vector Machine based classifiers. The induced magneticfield was produced by the interaction between an applied external field and the microstructure.Samples of the 2205 duplex stainless steel were thermal aged in order to obtain different amounts ofsigma phases (up to 18% in content). The obtained classification results were compared against theones obtained by Charpy impact energy test, amount of sigma phase, and analysis of the fracturesurface by scanning electron microscopy and X-ray diffraction. The proposed solution achieved aclassification accuracy superior to 95% and was revealed to be robust to signal noise, being thereforea valid testing tool to be used in this domain

    Core-sheath nanostructured chitosan-based nonwovens as a potential drug delivery system for periodontitis treatment.

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    Made available in DSpace on 2020-03-11T18:05:22Z (GMT). No. of bitstreams: 1 PCoresheathnanostructuredchitosanbasednonwovensasapotential....pdf: 3217193 bytes, checksum: 00e572c00c890368651d8c4bf9d5f62b (MD5) Previous issue date: 2019bitstream/item/207607/1/P-Core-sheath-nanostructured-chitosan-based-nonwovens-as-a-potential-....pd

    Effect of an extract of Centella asiatica on the biodistribution of sodium pertechnetate (Na<sup>99m</sup>TcO<sub>4</sub>) and on the fixation of radioactivity on blood constituents

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    This study evaluates the effects of an acute treatment with a Centella asiatica (CA) extract on the biodistribution of the radiopharmaceutical Na99mTcO4 and on the fixation of technetium-99m on blood constituents. Wistar rats were treated with CA extract and, 1 hour after, Na99mTcO4 was administered; organs/tissues were withdrawn and weighted. The radioactivity was counted to calculate the percentage of activity per gram (%ATI/g). Also, blood samples were withdrawn, plasma (P), blood cells (BC), insoluble fraction (IF) and soluble fractions of P and BC were isolated and the radioactivity was counted to calculate the percentage of activity (%ATI). Data indicated that the acute treatment with CA extract changed significantly (p99mTcO4 and the fixation of the technetium-99m on blood constituents in an acute treatment
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