335 research outputs found

    PrevalĂȘncia de alteraçÔes fundoscĂłpicas em estudantes na cidade de Natal-Brasil

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    Objetivo: Determinar a prevalĂȘncia de alteraçÔes fundoscĂłpicas em estudantes de escolas das redes pĂșblica e privada de Natal-RN. MĂ©todos: Avaliação oftalmolĂłgica foi realizada em 990 alunos, de 5 a 21 anos, matriculados nas escolas das redes pĂșblicas e privada do municĂ­pio de Natal-RN, que estiveram cursando alguma sĂ©rie do ensino fundamental ou mĂ©dio, no perĂ­odo de 03 a 06 de 2001. Resultados: AlteraçÔes fundoscĂłpicas foram observadas em 5,3% dos estudantes. As anormalidades encontradas, por ordem de freqĂŒĂȘncia, foram: branco sem pressĂŁo, 1,0%; cicatriz de retinocoroidite sugestiva de toxoplasmose, 1,0%; atrofia do epitĂ©lio pigmentado da retina, 0,8%; nevos da corĂłide, 0,4%; escavação da cabeça do nervo Ăłptico aumentada, 0,4%; degeneração em treliça, 0,3%; buraco operculado, 0,2%; fundus miĂłpico, 0,2%; tortuosidade vascular aumentada, 0,2%; granuloma sugestivo de toxocarĂ­ase, 0,2%; hipoplasia da cabeça do nervo Ăłptico, 0,1%; persistĂȘncia da artĂ©ria hialoidea, 0,1%; persistĂȘncia de fibras de mielina, 0,1%; retina sal e pimenta, 0,1%; retinosquise, 0,1%. ConclusĂŁo: Houve uma baixa prevalĂȘncia de alteraçÔes fundoscĂłpicas na população estudad

    Eugenia uniflora

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    Eugenia uniflora L. is a member of the Myrtaceae family and is commonly known as Brazilian cherry tree. In this study, we evaluated the chemical composition of Eugenia uniflora L. essential oil (EuEO) by using gas chromatography-mass spectrometry (GC-MS) and assessed its anti-Leishmania activity. We also explored the potential mechanisms of action and cytotoxicity of EuEO. Thirty-two compounds were identified, which constituted 92.65% of the total oil composition. The most abundant components were sesquiterpenes (91.92%), with curzerene (47.3%), Îł-elemene (14.25%), and trans-ÎČ-elemenone (10.4%) being the major constituents. The bioactivity shown by EuEO against promastigotes (IC50, 3.04 Όg·mL−1) and amastigotes (IC50, 1.92 Όg·mL−1) suggested significant anti-Leishmania activity. In the cytotoxicity determination, EuEO was 20 times more toxic to amastigotes than to macrophages. Hemolytic activity was 63.22% at the highest concentration tested (400 Όg·mL−1); however, there appeared to be no toxicity at 50 Όg·mL−1. While the data show that EuEO activity is not mediated by nitric oxide production, they do suggest that macrophage activation may be involved in EuEO anti-Leishmania activity, as evidenced by increases in both the phagocytic capacity and the lysosomal activity. More studies are needed to determine in vivo activity as well as additional mechanisms of the anti-Leishmania activity

    Viabilidade do Implante de Eletrodo Ventricular Esquerdo na Terapia de Ressincronização Cardíaca Guiada por Gated SPECT e Remodelamento Ventricular

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    Resumo Fundamento A terapia de ressincronização cardĂ­aca (TRC) pode beneficiar pacientes com insuficiĂȘncia cardĂ­aca (IC) avançada. O Ă­ndice de excentricidade anormal por gated SPECT estĂĄ relacionado a alteraçÔes estruturais e funcionais do ventrĂ­culo esquerdo (VE). Objetivo O objetivo do presente estudo foi avaliar a viabilidade do implante de eletrodos do VE guiado por anĂĄlise de fase e sua relação com o remodelamento ventricular. MĂ©todos Dezoito pacientes com indicação de TRC foram submetidos Ă  cintilografia miocĂĄrdica para orientar o implante, avaliando-se os parĂąmetros de excentricidade e forma ventricular. P < 0,05 foi adotado como significĂąncia estatĂ­stica. Resultados Na linha de base do estudo, a maioria dos pacientes foi classificada como NYHA 3 (n = 12). ApĂłs a TRC, 11 dos 18 pacientes foram reclassificados para um menor grau de limitação funcional. AlĂ©m disso, a qualidade de vida dos pacientes melhorou apĂłs a TRC. Foram observadas reduçÔes significativas na duração do QRS, intervalo PR, Ă­ndice de forma diastĂłlica final, Ă­ndice de forma sistĂłlica final, volume sistĂłlico e massa miocĂĄrdica pĂłs-TRC. O eletrodo do VE da TRC foi posicionado concordante, adjacente e discordante em 11 (61,1%), 5 (27,8%) e 2 (11,1%) pacientes, respectivamente. A excentricidade sistĂłlica e diastĂłlica final demonstrou remodelamento reverso apĂłs a TRC. ConclusĂ”es O implante de eletrodo do VE em TRC guiado por cintilografia gated SPECT Ă© viĂĄvel. A colocação do eletrodo concordante ou adjacente ao Ășltimo segmento a se contrair foi um determinante do remodelamento reverso

    Size effects on antimicrobial efficiency of DBD plasma coated silver nanoparticles on textiles

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    This work studies the surface characteristics, the antimicrobial activity and the aging effect, of plasma pre-treated polyamide 6,6 fabrics (PA66) coated with silver nanoparticles (AgNPs), with the aim to identify the optimum size of nanosilver exhibiting antibacterial properties suitable for manufacturing of hospital textiles. The release of bactericidal Ag+ ions from the 10, 20, 40, 60 and 100 nm AgNPs-coated PA66 surface were function of the particles size, number and aging. Plasma pre-treatment promoted both ionic and covalent interactions between AgNPs and the formed oxygen species on the fibers (Figure 1), favoring the deposition of smaller in diameter AgNPs that consequently showed better immediate and durable antimicrobial effect against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus bacteria. Surprisingly, after 30 days of aging, a comparable bacterial growth inhibition was achieved for all the fibers treated with AgNPs of <100 nm in size. The Ag+ in the coatings also favored the electrostatic stabilization of the plasma-induced functional groups on the PA66 surface, thereby retarding the aging process (Figure 2). At the same time, the size-related ratio Ag+/Ag0 of the AgNPs between 40 and 60 nm allowed for controlled release of Ag+ rather than bulk silver. Overall, the results suggest that instead of reducing the AgNPs size, which is associated to higher toxicity, similar long-term effects can be achieved with larger NPs (40-60 nm), even in lower concentrations. Since the antimicrobial efficiency of AgNPs larger than 30 nm is mainly ruled by the release of Ag+ over time and not by the size and number of the AgNPs, this parameter is crucial for the development of efficient antimicrobial coatings on plasma-treated surfaces, and contribution to the safety and durability of clothing used in clinical settings

    Size and aging effects on antimicrobial efficiency of silver nanoparticles coated on polyamide fabrics activated by atmospheric DBD plasma

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    Recently, renewed interest has arisen in silver nanopar@cles for biomedical devices because of their high surface energy, enhanced physicochemical and biological proper@es and extremely large surface area, which provides beAer contact with microorganisms. Atmospheric plasma is an alterna@ve and cost- compe@@ve method to wet chemical nanopar@cles deposi@on methods, avoiding the need of toxic solvents, expensive vacuum equipment and allowing con@nuous and uniform processing of material surfaces. However, there are no reports on the size and @me-dependent an@microbial, physical and chemical surface effects of the silver nanopar@cles immobilized on plasma func@onalized polymers. Thus, the purposes of this study were: (i) the silver nanopar@cle size and aging effects aCer 30 days on the an@microbial ac@vity aCer deposi@on onto DBD plasma-treated polyamide 6,6 fabrics, and (ii) the aging effect on the physico-chemical binding mechanism between different sized silver nanopar@cles and the plasma treaded polyamide 6,6. Five different in size commercial silver nanopar@cles have been employed (10, 20, 40 60 and 100 nm).This work was funded by Portuguese Founda@on for Science and Technology FCT/MCTES (PIDDAC) and co-financed by European funds (FEDER) through the PT2020 program, research project M-ERA-NET/0006/2014 and COMPETE program through FCT within the scope of the project POCI-01-0145-FEDER-007136 and UID/CTM/00264.info:eu-repo/semantics/publishedVersio

    Avanços e desafios da ciĂȘncia de recursos hĂ­dricos no Brasil: uma sĂ­ntese comunitĂĄria do XXIII SimpĂłsio Brasileiro de Recursos HĂ­dricos

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    In this paper we synthesize the special sessions of the XXIII Brazilian Water Resources Symposium 2019 in order to understand the major advances and challenges in the water sciences in Brazil. We analyzed more than 250 papers and presentations of 16 special sessions covering topics of Climate Variability and Change, Disasters, Modeling, Large Scale Hydrology, Remote Sensing, Education, and Water Resources Management. This exercise highlighted the unique diversity of natural and human water features in Brazil, that offers a great opportunity for understanding coupled hydrological and societal systems. Most contributions were related to methods and the quantification of water phenomena, therefore, there is a clear necessity for fostering more research on phenomena comprehension. There is a vast network of co-authorship among institutions but mostly from academia and with some degree of regional fragmentation. The ABRhidro community now has the challenge to enhance its collaboration network, the culture of synthesis analysis, and to build a common agenda for water resources research. It is also time for us to be aligned with the international water science community and to use our experiences to actively contribute to the tackling of global water issues.Este artigo apresenta uma sĂ­ntese das sessĂ”es especiais do XXIII SimpĂłsio Brasileiro de Recursos HĂ­dricos 2019, com o objetivo de compreender os principais avanços e desafios em recursos hĂ­dricos no Brasil. Foram analisados mais de 250 trabalhos e apresentaçÔes em 16 sessĂ”es especiais abrangendo temas como Variabilidade e Mudanças ClimĂĄticas, Desastres, Modelagem, Hidrologia de Grande Escala, Sensoriamento Remoto, Educação e GestĂŁo de Recursos HĂ­dricos. Esta avaliação destacou a diversidade Ășnica de atributos naturais e antrĂłpicos dos recursos hĂ­dricos brasileiros, que oferece uma grande oportunidade para aprendizado sobre sistemas hidrolĂłgico e humano acoplados. A maioria das contribuiçÔes Ă© relacionada a mĂ©todos e quantificação de fenĂŽmenos hĂ­dricos, existindo uma necessidade clara de incentivo a mais pesquisas em compreensĂŁo de fenĂŽmenos. Existe uma vasta rede de coautores, mas principalmente da academia e com certo grau de fragmentação regional. A comunidade da ABRhidro tem o desafio de aumentar a sua rede de colaboração, a cultura de anĂĄlises de sĂ­ntese, e construir uma agenda comum para a pesquisa em recursos hĂ­dricos. TambĂ©m Ă© o momento de alinhar esforços com a comunidade de recursos hĂ­dricos internacional, usando nossas experiĂȘncias para contribuir ativamente na solução de questĂ”es relacionadas Ă  ĂĄgua em nĂ­vel global

    A list of land plants of Parque Nacional do CaparaĂł, Brazil, highlights the presence of sampling gaps within this protected area

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    Brazilian protected areas are essential for plant conservation in the Atlantic Forest domain, one of the 36 global biodiversity hotspots. A major challenge for improving conservation actions is to know the plant richness, protected by these areas. Online databases offer an accessible way to build plant species lists and to provide relevant information about biodiversity. A list of land plants of “Parque Nacional do Caparaó” (PNC) was previously built using online databases and published on the website "Catálogo de Plantas das Unidades de Conservação do Brasil." Here, we provide and discuss additional information about plant species richness, endemism and conservation in the PNC that could not be included in the List. We documented 1,791 species of land plants as occurring in PNC, of which 63 are cited as threatened (CR, EN or VU) by the Brazilian National Red List, seven as data deficient (DD) and five as priorities for conservation. Fifity-one species were possible new ocurrences for ES and MG states

    Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

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    The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal
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