1,156 research outputs found

    CHEMICAL CHARACTERIZATION AND ANTIMICROBIAL ACTIVITY OF HYDROETHANOLIC CRUDE EXTRACT OF EUGENIA FLORIDA DC (MYRTACEAE) LEAVES

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    Objective: The present study aimed to characterize and quantify the total phenolics, flavonoids and tannins in a hydroethanolic crude extract (70% (v/v) (EB)) of the leaves of E. florida DC, as well as to evaluate the antimicrobial activity of the extract against different species of micro-organisms.Methods: EB was characterized using a mass spectrometer equipped with a direct insertion device for in-stream injection (FIA). Quantitative analyses of major compounds were carried out by spectrophotometry. In addition, we evaluated the sensitivity profiles of different strains of yeast and bacteria against different concentrations of EB.Results: The classes found were in agreement with those described in the literature: flavonoids, tannins, phenolic acids and saponins. EB showed levels of phenolic compounds, flavonoids and tannins equal to 25.82 mg gallic acid equivalents per gram of extract (EAG/g), 8.42 mg quercetin equivalents per gram of extract (EQ/g) and 7.30 mg tannic acid equivalents per gram of extract (AT/g), respectively. In the analysis of antimicrobial activity, EB was more active against yeasts but was not effective against the bacteria used in the test.Conclusion: We can conclude that E. florida DC has antimicrobial potential, due to the presence of bioactive secondary metabolites.Keywords: Phenolics, Micro-organisms, Mass spectrometer, Yeasts, Bacteria, PotentialÂ

    Influência de condicionadores na distribuição de poros em um Argissolo Amarelo Distrocoeso.

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    A porosidade do solo é o total de vazios ocupados por ar e água. Existe uma grande discussão em torno da melhor classificação a ser empregada. O modo como os poros são distribuídos determinam a retenção de água, aeração e movimentação no perfil do solo. Há duas classificações de poros usualmente aplicadas, a detalhada e a simplificada. Os Tabuleiros Costeiros possuem camadas coesas de solo que promovem alterações no estado da água no solo e interfere no desenvolvimento do sistema radicular das plantas. Identificar qual a classificação de poros que melhor se adapta sob ação de poliacrilamida e gesso compõe o objetivo deste estudo

    In vitro maturation impacts cumulus–oocyte complex metabolism and stress in cattle

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    FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOThe influence of in vitro maturation (IVM) in oocytes is still not totally understood. The aim of this study was to determine the influence of IVM on the metabolism and homeostasis of bovine cumulus-oocyte complexes. In the present study, we demonstrated1546881893FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO2014/21034-32014/03281-32014/22887-02013/08135-22012/50533-2306978/2014-8The authors would like to thank the staff and students at the LMMD, Marcos Chiaratti, Gustavo Duarte, Marcel Nakashima, Hélio Alves Martins Júnior, José Luis Paz Jara, Patricia Kubo Fontes and Augusto de Castro Netto for their assistance with the sample

    Genetic structuring and fixed polymorphisms in the gene period among natural populations of Lutzomyia longipalpis in Brazil

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    Citation: Costa, C. R. L., Freitas, M. T. D., Figueiredo, C. A. S., Aragao, N. C., da Silva, L. G., Marcondes, C. B., . . . Balbino, V. D. (2015). Genetic structuring and fixed polymorphisms in the gene period among natural populations of Lutzomyia longipalpis in Brazil. Parasites & Vectors, 8, 9. doi:10.1186/s13071-015-0785-6Background: Even one hundred years after being originally identified, aspects of the taxonomy of the sand fly Lutzomyia longipalpis, the principal vector of Leishmania infantum in the Americas, remain unresolved for Brazilian populations of this vector. The diversity of morphological, behavioral, biochemical, and ethological characters, as well as the genetic variability detected by molecular markers are indicative of the presence of a complex of species. Methods: In this study, a 525 bp fragment of the period gene was used to evaluate sympatric populations of L. longipalpis. A combination of probabilistic methods such as maximum likelihood and genetic assignment approach to investigate sympatric species of L. longipalpis were applied in three populations of Northeast Brazil. Results: Fixed polymorphisms in geographically isolated populations of L. longipalpis from two localities in the state of Ceara and one in the state of Pernambuco, Brazil, was identified in a 525 bp fragment of the gene period (per). Our results suggest a direct relationship between the number of spots found in males' tergites and the genetic variation in cryptic species of L. longipalpis. The fragment used in this study revealed the nature of the ancestral morphotype 1S. Conclusion: New polymorphisms were identified in the gene per which can be used as a genetic barcode to sympatric taxonomy of L. longipalpis. The per gene fragment confirmed the presence of two siblings species of L. longipalpis in Sobral and showed that these same species are present in two other localities, representing an expansion within the L. longipalpis species complex with regards to the states of Ceara and Pernambuco

    Busca de inibidores da enzima glicossomal gliceraldeído 3-fosfato desidrogenase de Trypanosoma cruzi

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    The inhibitory activity of crude extracts of Meliaceae and Rutaceae plants on glycosomal glyceraldehyde-3-phosphate dehydrogenase (gGAPDH) enzyme from Trypanosoma cruzi was evaluated at 100 μg/mL. Forty-six extracts were tested and fifteen of them showed significant inhibitory activity (IA % > 50). The majority of the assayed extracts of Meliaceae plants (Cedrela fissilis, Cipadessa fruticosa and Trichilia ramalhoi) showed high ability to inhibit the enzymatic activity. The fractionation of the hexane extract from branches of C. fruticosa led to the isolation of three flavonoids: flavone, 7-methoxyflavone and 3',4',5',5,7-pentamethoxyflavone. The two last compounds showed high ability to inhibit the gGAPDH activity. Therefore, the assayed Meliaceae species could be considered as a promising source of lead compounds against Chagas' disease.Nesse trabalho foi avaliada a atividade inibitória sobre a enzima glicossomal gliceraldeído-3-fosfato desidrogenase de T. cruzi (gGAPDH) de extratos vegetais oriundos de plantas das famílias Meliaceae e Rutaceae, na concentração de 100 μg/mL. Foram testados 46 extratos, dos quais 15 apresentaram atividade inibitória significativa (% AI > 50). A maioria dos extratos de plantas da família Meliaceae (Cedrela fissilis, Cipadessa fruticosa e Trichilia ramalhoi) apresentou grande potencial em inibir a atividade enzimática. O fracionamento do extrato hexânico dos galhos de C. fruticosa permitiu o isolamento de três flavonóides: flavona, 7-metoxiflavona e 3',4',5',5,7-pentametoxiflavona. Os dois últimos foram ativos na inibição da atividade de gGAPDH. Desta forma, as três espécies de Meliaceae testadas podem ser consideradas promissoras na busca de compostos protótipos para o controle da doença de Chagas.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Ensino Superior (CAPES)FINEP - Financiadora de Estudos e Projeto

    Adsorption of cobalt ferrite nanoparticles within layer-by-layer films: a kinetic study carried out using quartz crystal microbalance

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    The paper reports on the successful use of the quartz crystal microbalance technique to assess accurate kinetics and equilibrium parameters regarding the investigation of in situ adsorption of nanosized cobalt ferrite particles (CoFe2O4-10.5 nm-diameter) onto two different surfaces. Firstly, a single layer of nanoparticles was deposited onto the surface provided by the gold-coated quartz resonator functionalized with sodium 3-mercapto propanesulfonate (3-MPS). Secondly, the layer-by-layer (LbL) technique was used to build multilayers in which the CoFe2O4 nanoparticle-based layer alternates with the sodium sulfonated polystyrene (PSS) layer. The adsorption experiments were conducted by modulating the number of adsorbed CoFe2O4/PSS bilayers (n) and/or by changing the CoFe2O4 nanoparticle concentration while suspended as a stable colloidal dispersion. Adsorption of CoFe2O4 nanoparticles onto the 3-MPS-functionalized surface follows perfectly a first order kinetic process in a wide range (two orders of magnitude) of nanoparticle concentrations. These data were used to assess the equilibrium constant and the adsorption free energy. Alternatively, the Langmuir adsorption constant was obtained while analyzing the isotherm data at the equilibrium. Adsorption of CoFe2O4 nanoparticles while growing multilayers of CoFe2O4/PSS was conducted using colloidal suspensions with CoFe2O4 concentration in the range of 10-8 to 10-6 (moles of cobalt ferrite per litre) and for different numbers of cycles n = 1, 3, 5, and 10. We found the adsorption of CoFe2O4 nanoparticles within the CoFe2O4/PSS bilayers perfectly following a first order kinetic process, with the characteristic rate constant growing with the increase of CoFe2O4 nanoparticle concentration and decreasing with the rise of the number of LbL cycles (n). Additionally, atomic force microscopy was employed for assessing the LbL film roughness and thickness. We found the film thickness increasing from about 20 to 120 nm while shifting from 3 to 10 CoFe2O4/PSS bilayers, using the 8.9 × 10-6 (moles of cobalt ferrite per litre) suspension.MCT/CNPqFINEPCAPESFUNAPEFINATE

    Comparative study and anticholinesterasic evaluation of essential oils from leaves, stems and flowers of myrciaria floribunda (H.West ex Willd.) O. Berg

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    Myrciaria floribunda (H.West ex Willd.) O.Berg, Myrtaceae, popularly known as “camboim amarelo”, was collected in Restinga de Jurubatiba (RJ, Brazil). Leaves, stems and flowers were individually submitted to hydrodistillation, affording the respective essential oils. Monoterpenes were the main group of essential oils from leaves (53.9 %) and flowers (55.4 %). Sesquiterpenes were more representative in stems (72.2 %). 1,8-cineole was the major constituent in the essential oil from leaves (38.4 %) and flowers (22.8 %). The major constituent from stems was (2E,6E)-farnesyl acetate (19.9 %). To our knowledge, these are the first contributions for essential oils from stems and flowers of M. floribunda. It was also performed the acetylcholinesterase inhibitory bioassay of the essential oil from stems, flowers and leaves of M. floribunda. Flowers and leaves oils had an IC50 of 1583 and 681 μg/mL, respectively, being both low to mild values.Colegio de Farmacéuticos de la Provincia de Buenos Aire

    Specificity and selectivity improvement in doping analysis using comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry

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    Comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry was used for the identification of forty doping agents. The improvement in the specificity was remarkable, allowing the resolution of analytes that could not be done by one-dimensional chromatographic systems. The sensitivity observed for different classes of prohibited substances was clearly below the value required by the World Anti-Doping Agency. In addition time-of-flight mass spectrometry gives full spectrum for all analytes without any interference from the matrix, resulting in selectivity improvements. These results could support the implementation of an exhaustive monitoring approach for hundreds of doping agents in a single injection

    Insecticide resistance in Aedes aegypti populations from Ceará, Brazil

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    <p>Abstract</p> <p>Background</p> <p>Organophosphates and pyrethroids are used widely in Brazil to control <it>Aedes aegypti</it>, the main vector of dengue viruses, under the auspices of the National Programme for Dengue Control. Resistance to these insecticides is widespread throughout Brazil. In Ceará the vector is present in 98% of districts and resistance to temephos has been reported previously. Here we measure resistance to temephos and the pyrethroid cypermethrin in three populations from Ceará and use biochemical and molecular assays to characterise resistance mechanisms.</p> <p>Results</p> <p>Resistance to temephos varied widely across the three studied populations, with resistance ratios (RR<sub>95</sub>) of 7.2, 30 and 192.7 in Juazeiro do Norte, Barbalha and Crato respectively. The high levels of resistance detected in Barbalha and Crato (RR<sub>95 </sub>≥ 30) imply a reduction of temephos efficacy, and indeed in simulated field tests reduced effectiveness was observed for the Barbalha population. Two populations (Crato and Barbalha) were also resistant to cypermethrin, whilst Juazeiro do Norte showed only an altered susceptibility. The <it>Ile1011Met kdr </it>mutation was detected in all three populations and <it>Val1016Ile </it>in Crato and Juazeiro do Norte. <it>1011Met </it>was significantly associated with resistance to cypermethrin in the Crato population. Biochemical tests showed that only the activity of esterases and GSTs, among the tested detoxification enzymes, was altered in these populations when compared with the Rockefeller strain.</p> <p>Conclusions</p> <p>Our results demonstrate that two <it>A. aegypti </it>populations from Ceará are under strong selection pressure by temephos, compromising the field effectiveness of this organophosphate. Our results also provide evidence that the process of reducing resistance to this larvicide in the field is difficult and slow and may require more than seven years for reversal. In addition, we show resistance to cypermethrin in two of the three populations studied, and for the first time the presence of the allele <it>1016Ile </it>in mosquito populations from northeastern Brazil. A significant association between <it>1011M</it>et and resistance was observed in one of the populations. Target-site mechanisms seem not to be implicated in temephos resistance, reinforcing the idea that for the studied populations, detoxification enzymes most likely play a major role in the resistance to this insecticide.</p
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