448 research outputs found

    New species and new record of anthomedusae from southern Brazil

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    A new species of Hydromedusa belonging to the genus Octocanna Haeckel 1879, here revived, is described from the coastal waters off Santos. The new species belongs to the family Phialuciidae, it is named Octocanna haeckeli sp. n. and differs from the other two species of the genus in being smaller, in having a high dome shaped umbrella, four tentacles, eight bulbs and eight marginal vesicles at sexual maturity. The genus Octocanna is here revived for Phialuciidae with eight radial canals, eight gonads, four or more tentacles and never more than four lips. The genus Octophialucium Kramp 1955 is considered valid for Phialuciidae with eight radial canals, eight gonads and eight lips. In the same series of samples, some specimens of Octophialucium bigelowi Kramp 1955 were taken which are very similar to Octocanna haeckeli but have eight lips, eight tentacles, rudimentary bulbs and a larger number of marginal vesicles at sexual maturity, which is reached at approximately the same umbrella size. The two similar species were taken in the same water mass at approximately the same time of the same year.Descreve-se uma nova espécie de hidromedusa, coletada em águas costeiras próximas a Santos, pertencente ao gênero Octocanna Haeckel 1879. Este gênero foi considerado obsoleto por KRAMP, mas o achado presente mostra que deve ser reestabelecido. A nova espécie chamada Otocanna haeckeli pertence à família Phialuciidae. Difere das outras duas espécies do mesmo gênero por ser menor, ter umbrela alta em forma de domo, 4 tentáculos, 8 bulbos e 8 vesículas marginais quando atinge a maturidade sexual. A validade do gênero Octocanna fica restabelecida para as Phialuciidae com 8 canais radiais, 8 gônadas, 4 ou mais tentáculos e nunca mais do que 4 lábios. O gênero Octophialucium Kramp 1955 é mantido como válido para Phialuciidae com 8 canais radiais, 8 gônadas e 8 lábios. Na mesma série de amostras foram coletados alguns espécimes de Octophialucium bigelowi Kramp 1955 que se assemelham à primeira vista a Octocanna haeckeli, mas têm 8 lábios, 8 tentáculos, bulbos rudimentares e um número maior de vesículas marginais quando sexualmente maduros. Ambas as espécies atingem a maturidade com aproximadamente o mesmo tamanho e foram coletadas na mesma massa d'água, em datas próximas do mesmo ano

    Structural and optical characterization of Mg-doped GaAs nanowires grown on GaAs and Si substrates

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    We report an investigation on the morphological, structural, and optical properties of large size wurtzite GaAs nanowires, low doped with Mg, grown on GaAs(111) B and Si(111) substrates. A higher density of vertical nanowires was observed when grown upon GaAs(111) B. Very thin zinc-blende segments are observed along the axis of the nanowires with a slightly higher linear density being found on the nanowires grown on Si(111). Low temperature cathodoluminescence and photoluminescence measurements reveal an emission in the range 1.40-1.52 eV related with the spatial localization of the charge carriers at the interfaces of the two crystalline phases. Mg related emission is evidenced by cathodoluminescence performed on the GaAs epilayer. However, no direct evidence for a Mg related emission is found for the nanowires. The excitation power dependency on both peak energy and intensity of the photoluminescence gives a clear evidence for the type II nature of the radiative transitions. From the temperature dependence on the photoluminescence intensity, non-radiative de-excitation channels with different activation energies were found. The fact that the estimated energies for the escape of the electron are higher in the nanowires grown on Si(111) suggests the presence of wider zinc-blende segments. (C) 2013 AIP Publishing LLC

    Evaluation of the proteomic profiles of ejaculated spermatozoa from Saanen bucks (Capra hircus).

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    Abstract: The Saanen goat breed has been widely explored in breeding programmes; however, there are few reports about the breed?s genetic and molecular composition. Thus, this study aimed to characterize the proteomic profile of spermatozoa from Saanen breeding goats. Five breeding animals with proven fertility were selected, the spermatozoa were collected, and the protein was extracted. Subsequently, the proteins were separated and analysed by two-dimensional electrophoresis and mass spectrometry; the proteins were then identified with the SwissProt database. A total of 31 proteins involved in reproduction were identified, including binding proteins on spermatozoa for fusion with the egg, acrosomal membrane proteins, metabolic enzymes, heat shock proteins, cytoskeletal proteins and spermatozoa motility proteins. The characterization of such proteins clarifies the molecular mechanisms of spermatogenesis and the modifications that ensure the success of fertilization

    Chloroquine-containing organoruthenium complexes are fast-acting multistage antimalarial agents

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    © Cambridge University Press 2016We report the pharmacological activity of organoruthenium complexes containing chloroquine (CQ) as a chelating ligand. The complexes displayed intraerythrocytic activity against CQ-sensitive 3D7 and CQ-resistant W2 strains of Plasmodium falciparum, with potency and selectivity indexes similar to those of CQ. Complexes displayed activity against all intraerythrocytic stages, but moderate activity against Plasmodium berghei liver stages. However, unlike CQ, organoruthenium complexes impaired gametocyte viability and exhibited fast parasiticidal activity against trophozoites for P. falciparum. This functional property results from the ability of complexes to quickly induce oxidative stress. The parasitaemia of P. berghei-infected mice was reduced by treatment with the complex. Our findings demonstrated that using chloroquine for the synthesis of organoruthenium complexes retains potency and selectivity while leading to an increase in the spectrum of action and parasite killing rate relative to CQ.This research was funded by FAPESB (grant PET0042/2013, Brazil) to M.B.P.S, FAPESP (grant 14/10516-7, Brazil) to A.A.B. and Fundação para a Ciência e Tecnologia (grant PTDC/SAU-MIC/117060/2010 Portugal) to M.P. A.A.B. and M.B.P.S. are recipients of senior fellowships by CNPq (Brazil)info:eu-repo/semantics/publishedVersio

    Urochloa decumbens pasture recovery with management systems and phosphate fertilization.

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    Título em português: Recuperação de pastagem de Urochloa decumbens com sistemas de manejo e adubação fosfatada. Título em Espanhol: fertilization Recuperación de pasto de Urochloa decumbens con sistemas de manejo y fertilización de fosfato

    Tachykinin receptors antagonism for asthma: a systematic review

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    <p>Abstract</p> <p>Background</p> <p>Tachykinins substance P, neurokinin A and neurokinin B seem to account for asthma pathophysiology by mediating neurogenic inflammation and several aspects of lung mechanics. These neuropeptides act mainly by their receptors NK1, NK2 and NK3, respectively which may be targets for new asthma therapy.</p> <p>Methods</p> <p>This review systematically examines randomized controlled trials evaluating the effect of tachykinins receptors antagonism on asthma. Symptoms, airway inflammation, lung function and airway inflammation were considered as outcomes. We searched the Cochrane Airways Group Specialized Register of Asthma Trials, Cochrane Database of Systematic Reviews, MEDLINE/PubMed and EMBASE. The search is as current as June 2010. Quality rating of included studies followed the Cochrane Collaboration and GRADE Profiler approaches. However, data were not pooled together due to different measures among the studies.</p> <p>Results</p> <p>Our systematic review showed the potential of NK receptor antagonist to decrease airway responsiveness and to improve lung function. However, effects on airway inflammation and asthma symptoms were poorly or not described.</p> <p>Conclusion</p> <p>The limited available evidence suggests that tachykinin receptors antagonists may decrease airway responsiveness and improve lung function in patients with asthma. Further large randomized trials are still required.</p
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