14,363 research outputs found

    Atomically thin dilute magnetism in Co-doped phosphorene

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    Two-dimensional dilute magnetic semiconductors can provide fundamental insights in the very nature of magnetic orders and their manipulation through electron and hole doping. Despite the fundamental physics, due to the large charge density control capability in these materials, they can be extremely important in spintronics applications such as spin valve and spin-based transistors. In this article, we studied a two-dimensional dilute magnetic semiconductors consisting of phosphorene monolayer doped with cobalt atoms in substitutional and interstitial defects. We show that these defects can be stabilized and are electrically active. Furthermore, by including holes or electrons by a potential gate, the exchange interaction and magnetic order can be engineered, and may even induce a ferromagnetic-to-antiferromagnetic phase transition in p-doped phosphorene.Comment: 7 pages, 4 colorful figure

    Co‐existing monophasic teratoma and uterine adenocarcinoma in a female dog

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    Ovarian teratomas are occasionally reported in dogs; the rarest type is the monophasic teratoma,composed of tissues originating from only one germ layer. Canine endometrial adenocarcinomas are also rare in dogs and mainly affect geriatric females. This report describes case of co-existing ovarian teratoma and uterine adenocarcinoma in a 10-year old nulliparous female Boxer presented with lethargy, anorexia and purulent vaginal discharge. Abdominal ultrasonography evidenced pyometra and a mass in the left ovary. This was composed of a uniform whitish tissue with multiple cystic structures. The histology revealed an atrophy of the ovarian parenchyma, compressed by a proliferation of well-differentiated nervous tissue staining positively to vimentin, S100 and neuronal specific enolase (NSE), and negatively to keratin and inhibin. The left uterine horn, whose diameter was markedly increased, showed foci of endometrial cellular atypia, evident nucleoli and mitoses, at light microscopy. To our best knowledge, this is the first report of a coexisting ovarian monophasic teratoma and endometrial adenocarcinoma, two rare reproductive neoplasia in dogs

    Evolutionary Constraints in the b-Globin Cluster: The Signature of Purifying Selection at the d-Globin (HBD) Locus and Its Role in Developmental Gene Regulation

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    Human hemoglobins, the oxygen carriers in the blood, are composed by two α-like and two β-like globin monomers. The β-globin gene cluster located at 11p15.5 comprises one pseudogene and five genes whose expression undergoes two critical switches: the embryonic-to-fetal and fetal-to-adult transition. HBD encodes the δ-globin chain of the minor adult hemoglobin (HbA2), which is assumed to be physiologically irrelevant. Paradoxically, reduced diversity levels have been reported for this gene. In this study, we sought a detailed portrait of the genetic variation within the β-globin cluster in a large human population panel from different geographic backgrounds. We resequenced the coding and noncoding regions of the two adult β-globin genes (HBD and HBB) in European and African populations, and analyzed the data from the β-globin cluster (HBE, HBG2, HBG1, HBBP1, HBD, and HBB) in 1,092 individuals representing 14 populations sequenced as part of the 1000 Genomes Project. Additionally, we assessed the diversity levels in nonhuman primates using chimpanzee sequence data provided by the PanMap Project. Comprehensive analyses, based on classic neutrality tests, empirical and haplotype-based studies, revealed that HBD and its neighbor pseudogene HBBP1 have mainly evolved under purifying selection, suggesting that their roles are essential and nonredundant. Moreover, in the light of recent studies on the chromatin conformation of the β-globin cluster, we present evidence sustaining that the strong functional constraints underlying the decreased contemporary diversity at these two regions were not driven by protein function but instead are likely due to a regulatory role in ontogenic switches of gene expression

    A Expressão Global da Doença de Chagas – Oportunidades Emergentes e Impacto em Portugal

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    Chagas disease, caused by the protozoan Trypanosoma cruzi is endemic in the countries of Central and South America. Despite vector control programs and other measures taken in the blood banks and maternity hospitals, it is estimated that there are about eight million people infected worldwide. Although traditionally associated with rural life and poverty, the current migration flows transform it into a global public health problem. In Portugal, this problem is poorly known, with an estimated underdiagnosis index that exceeds 99%. In European countries, besides imported cases, autochthonous infections arise through vertical transmission and blood/organ donation.The conventional serological tests for diagnosing Chagas disease and verifying its cure are indirect hemagglutination (IHA), indirect immunofluorescence (IFAT), and enzyme-linked immunoabsorbent assay (ELISA).The hypothesis of autoimmunity as a basic mechanism of this disease and the absence of early markers of cure are the causes of controversy regarding the specific treatment of this disease. The currently available drugs have adverse effects on a large number of patients and parasitological efficacy in chronic disease is suboptimal.The authors reinforce the need of a high level of suspicion in patients with suggestive epidemiology and the need of populational screening of specific high risk groups

    Uma estratégia interativa para a expansão de expressões de busca utilizando vocabulário controlado.

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    Neste trabalho apresenta-se a evolução do sistema de busca da Agência de Informação Embrapa, a partir de uma estratégia interativa de expansão de expressões de busca. Embora a Agência prime pela oferta de informação altamente qualificada, seus usuários não utilizam todo esse potencial, por desconhecer seus detalhes. A estratégia proposta permite que o usuário especifique sua expressão de busca e o sistema sugira formas de expandi-la, deixando a escolha final para o usuário. Os experimentos realizados foram baseados em possibilidades automaticamente geradas e medidos de forma objetiva, considerando-se a precisão e a cobertura das buscas realizadas. Como esperado, os experimentos mostram que o uso de uma melhor qualificação das expressões permite obter resultados mais precisos e que a evolução da ferramenta atingiu seu objetivo.bitstream/item/56769/1/BolPesq30.pd

    Expansão de busca utilizando vocabulário controlado.

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    O objetivo dessa proposta é expandir as expressões de busca especificadas pelo usuário, de modo a abrir o leque de resultados, melhorando especialmente a cobertura destes, conferindo uma maior precisão nos resultados das buscas

    Dileptons from the nonequilibrium Quark-Gluon Plasma

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    According to the dynamical quasiparticle model (DQPM) -- matched to reproduce lattice QCD results in thermodynamic limit, -- the constituents of the strongly interacting quark-gluon plasma (sQGP) are massive and off-shell quasi-particles (quarks and gluons) with broad spectral functions. In order to address the electromagnetic radiation of the sQGP, we derive off-shell cross sections of qqˉγq\bar q\to\gamma^*, qqˉγ+gq\bar q\to\gamma^*+g and qgγqqg\to\gamma^*q(qˉgγqˉ\bar q g\to\gamma^* \bar q) reactions taking into account the effective propagators for quarks and gluons from the DQPM. Dilepton production in In+In collisions at 158 AGeV is studied by implementing these processes into the parton-hadron-string dynamics (PHSD) transport approach. The microscopic PHSD transport approach describes the full evolution of the heavy-ion collision: from the dynamics of quasi-particles in the sQGP phase (when the local energy density is above 1\sim 1 GeV/fm3^3) through hadronization and to the following hadron interactions and off-shell propagation after the hadronization. A comparison to the data of the NA60 Collaboration shows that the low mass dilepton spectra are well described by including a collisional broadening of vector mesons, while the spectra in the intermediate mass range are dominated by off-shell quark-antiquark annihilation, quark Bremsstrahlung and gluon-Compton scattering in the nonperturbative QGP. In particular, the observed softening of the mTm_T spectra at intermediate masses (1 GeV M\le M \le 3 GeV) is approximately reproduced.Comment: 8 pages, 8 figures, to be published in the Proceedings of the 26th Winter Workshop on `Nuclear Dynamics', Ochto Rios, Jamaica, 2-9 January, 201
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