506 research outputs found

    Cerebral Sinovenous Thrombosis in Children: Clinical Presentation and Extension, Localization and Recanalization of Thrombosis

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    Many important questions regarding pathophysiology and treatment of cerebral sinovenous thrombosis need clarification and may depend on further knowledge on the etiology, site, extension and recanalization of the thrombosis. We studied these variables in a cohort of children and adolescents from seven Portuguese Centers. We conclude from our results that the deep venous system and the superior longitudinal sinus are less frequently affected with thrombosis but have a greater potential for serious neurologic disease and for major sequelae. Non-recanalization, at least in the long term, is not an adverse prognostic factor. Extensive propagation of the thrombus from the initial site of origin seems to be common. The early identification of risk factors and their treatment coupled with an aggressive attitude towards diagnosis and treatment for thrombosis involving the deep venous system would be warranted

    An unusual overrepresentation of genetic factors related to iron homeostasis in the genome of the fluorescent Pseudomonas sp. ABC1

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    Members of the genus Pseudomonas inhabit diverse environments, such as soil, water, plants and humans. The variability of habitats is reflected in the diversity of the structure and composition of their genomes. This cosmopolitan bacterial genus includes species of biotechnological, medical and environmental importance. In this study, we report on the most relevant genomic characteristics of Pseudomonas sp. strain ABC1, a siderophore-producing fluorescent strain recently isolated from soil. Phylogenomic analyses revealed that this strain corresponds to a novel species forming a sister clade of the recently proposed Pseudomonas kirkiae. The genomic information reveals an overrepresented repertoire of mechanisms to hoard iron when compared to related strains, including a high representation of fecI-fecR family genes related to iron regulation and acquisition. The genome of the Pseudomonas sp. ABC1 contains the genes for non-ribosomal peptide synthetases (NRPSs) of a novel putative Azotobacter-related pyoverdine-type siderophore, a yersiniabactin-type siderophore and an antimicrobial betalactone; the last two are found only in a limited number of Pseudomonas genomes. Strain ABC1 can produce siderophores in a low-cost medium, and the supernatants from cultures of this strain promote plant growth, highlighting their biotechnological potential as a sustainable industrial microorganism. © 2021 The Authors. Microbial Biotechnology published by Society for Applied Microbiology and John Wiley & Sons Ltd

    Quantum state transformation by dispersive and absorbing four-port devices

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    The recently derived input-output relations for the radiation field at a dispersive and absorbing four-port device [T. Gruner and D.-G. Welsch, Phys. Rev. A 54, 1661 (1996)] are used to derive the unitary transformation that relates the output quantum state to the input quantum state, including radiation and matter and without placing frequency restrictions. It is shown that for each frequency the transformation can be regarded as a well-behaved SU(4) group transformation that can be decomposed into a product of U(2) and SU(2) group transformations. Each of them may be thought of as being realized by a particular lossless four-port device. If for narrow-bandwidth radiation far from the medium resonances the absorption matrix of the four-port device can be disregarded, the well-known SU(2) group transformation for a lossless device is recognized. Explicit formulas for the transformation of Fock-states and coherent states are given.Comment: 24 pages, RevTe

    Proporção Corporal em Crianças e Adolescentes com Síndrome de Down

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    ResumoO presente estudo teve como objetivo avaliar as proporções corporais entre estatura tronco-cefálica e comprimento de pernas de crianças e adolescentes com Síndrome de Down (SD). Para tanto, a amostra foi composta por 99 pessoas SD (40 meninas com idade média de 11,45±2,6 anos e 59 meninos com 12,07±3,0 anos). Os seguintes parâmetros foram coletados: idade cronológica, estatura, estatura tronco-cefálica e comprimento de pernas. As proporções corporais dos segmentos foram calculadas através dos índices corpóreos e modelo Phantom. Para a análise estatística recorreu-se ao teste de normalidade e análises descritivas de tendência central e dispersão, posteriormente, foi adotado o teste t de Student. Para todos os tratamentos utilizou-se o programa estatístico SPSS 13.0 e nível de significância de p<0,05. Observou-se que, a proporção corporal entre os segmentos superiores e inferiores de crianças e adolescentes com SD apresenta diferença quando comparado a população típica. Sendo esta diferença para comprimento de pernas, e a proporção de estatura tronco-cefálica atingiu valores próximos aos intervalos da população sem SD.AbstractThe present study aimed to evaluate the body proportions of sitting height and leg length in children and adolescents with Down’s syndrome (DS). The sample consisted of 99 individuals with DS (40 girls with an average age of 11.45 ± 2.6 years and 59 boys with an average age of 12.07 ± 3.0 years). The following parameters were studied: chronological age, height, sitting height and leg length. The body proportions of each segment were calculated using body indices and the Phantom model. For the statistical analysis, the normality test and descriptive analyses of central tendency and dispersion were performed, and Student’s t-test was used. For all treatments, the statistical software program SPSS version 13.0 was used, and a significance level of p < 0.05 was set. The body proportion of the upper and lower segments of children and adolescents with DS differed from those of the typical population in terms of leg length, whereas the seated height values of individuals with DS †were similar to those of individuals without DS

    On quantum teleportation with beam-splitter-generated entanglement

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    Following the lead of Cochrane, Milburn, and Munro [Phys. Rev. A {\bf 62}, 062307 (2000)], we investigate theoretically quantum teleportation by means of the number-sum and phase-difference variables. We study Fock-state entanglement generated by a beam splitter and show that two-mode Fock-state inputs can be entangled by a beam splitter into close approximations of maximally entangled eigenstates of the phase difference and the photon-number sum (Einstein-Podolsky-Rosen -- EPR -- states). Such states could be experimentally feasible with on-demand single-photon sources. We show that the teleportation fidelity can reach near unity when such ``quasi-EPR'' states are used as the quantum channel.Comment: 7 pages (two-column), 7 figures, submitted to Phys. Rev. A. Text unmodified, postscript error correcte

    Antiferromagnetic 4-d O(4) Model

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    We study the phase diagram of the four dimensional O(4) model with first (beta1) and second (beta2) neighbor couplings, specially in the beta2 < 0 region, where we find a line of transitions which seems to be second order. We also compute the critical exponents on this line at the point beta1 =0 (F4 lattice) by Finite Size Scaling techniques up to a lattice size of 24, being these exponents different from the Mean Field ones.Comment: 26 pages LaTeX2e, 7 figures. The possibility of logarithmic corrections has been considered, new figures and tables added. Accepted for publication in Physical Review

    Pontos de carbono luminescentes à base de ovalbumina aplicados em marcação biológica

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    Entre os nanomateriais de carbono, os pontos de carbono (PCs) estão entre os mais atraentes devido as suas interessantes propriedades fotoluminescentes. Os PCs apresentam processo de síntese fácil, possibilidade de funcionalização da superfície, baixa toxicidade, alta solubilidade em água e biocompatibilidade. Devido a isso, suas aplicações na área biomédica e de bioimagem tem se destacado na literatura. Neste trabalho, PCs foram sintetizados por dois métodos diferentes a partir da ovalbumina, o qual é um precursor não tóxico e composto predominantemente por aminoácidos de cadeia curta. Os PCs foram caracterizados por espectroscopias de absorção (UV-Vis), de emissão (fluorescência) e infravermelho (IVTF), além de análise termogravimétrica (ATG). Os PCs foram utilizados como sondas fluorescentes para uma imagem colorida (azul e verde) de células HEK293 e não induziram a morte celular, o que indica que os mesmos são biocompatíveis e não tóxicos para este tipo de células. Dessa forma, os resultados aqui apresentados demonstram que os PCs podem ser considerados potenciais substitutos para corantes comerciais em marcação biológica.Palavras-chave: nanopartículas de carbono, fotoluminescência, biocompatibilidade, HEK293.

    Biometric differences between several populations of Cordulegaster boltonii (Odonata: Cordulegastridae) in Ibero-Maghrebian area

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    Biometric data of the exuviae of female larvae of the dragonfly Cordulegaster boltonii collected in Portugal, Spain and Morocco were analysed to determine whether the size of three exuvial structures measured differed depending on the geographic localities of the populations. Based on the results recorded for the 16 populations studied, head width was negatively correlated with latitude and the greatest length of the gonapophysis was recorded for the Iberian populations at the centre of this peninsula. Multivariate cluster analysis revealed a clear separation of the Moroccan population. A second cluster separated the southernmost population (Sierra Nevada) from the remaining Iberian populations. Four population groups were distinguished: those located in watercourses in the north and central area of the Iberian Peninsula, those in Iberian watercourses in the East and Middle South, the Sierra Nevada and North Morocco. Some of these results coincide with the results of genetic studies of other authors
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