5,884 research outputs found

    AVC isquémico em doente jovem - caso clínico

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    A população jovem adulta é afectada numa minoria por acidentes vasculares cerebrais isquémicos (ACVi), mas em cerca de 40% dos casos, estes são criptogénicos. Nestes doentes é raramente possível documentar a existência de uma comunicação inter-auricular (CIA) do tipo ostium secundum. Esta patologia invulgar está associada a um aumento do rico de AVCi por embolia paradoxal. Os autores apresentam o caso de um doente de 32 anos, sem antecedentes relevantes, desportista que recorreu ao serviço de urgência por parestesias do hemicorpo esquerdo e hemiparésia flácida do membro superior esquerdo confirmado no exame neurológico sumário. Realizou tomografia computorizada crânio-encefalica (CE), com evidência de ténue hipodensidade focal na região da coroa radiata direita, podendo corresponder a lesão isquémica recente ou etiologia inflamatório/desmielinizante. Ficou internado para estudo etiológico. Neste contexto realizou ecodoppler carotídeo, Holter, punção lombar com exame citoquímico e bacteriológico do líquido cefalorraquidiano que não revelaram alterações; o rastreio de trombofilias e patologias auto-imunes foi negativo assim como serologias virais. Fez ressonância magnética CE, que mostrou duas lesões isquémicas situadas no córtex do girus pós-central e subcortical central á direita com alterações compatíveis com lesões lacunares na região frontal bilateral. Realizou ecocardiogramas transtorácico e transesofágico que revelaram solução de continuidade compatível com CIA tipo ostium secundum de 14mm, com cavidades direitas dilatadas. Iniciou anticoagulação oral e foi referenciado á consulta de Cardiopatias Congénitas, aguardando cirurgia. Está actualmente clinicamente estabilizado, sob anticoagulação com varfarina

    Pancitopénia e hiperpigmentação cutânea: uma associação inesperada

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    A anemia carêncial é uma uma patologia pouco prevalente na sociedade actual, acometendo uma população com características muito específicas. O défice de ácido fólico pode cursar com a rara apresentação de hiperpigmentação, por mecanismos que ainda não estão completamente esclarecidos. Os autores descrevem o caso clínico de um doente com 81 anos de idade, sexo masculino, caucasiano, com antecedentes pessoais de anemia recém-diagnosticada, sob terapêutica marcial há cerca de 2 meses. Recorreu ao serviço de urgência por cansaço fácil, anorexia e astenia. Ao exame objectivo de salientar marcada hiperpigmentação cutânea na face, região cervical e mãos. O doente negava exposição solar prolongada, referindo uma dieta pouco diversificada, alimentando-se a base de bolachas e iogurtes nos últimos 4 meses. Negava ingesta diária de leguminosas carnes ou peixe. Dos exames complementares de diagnóstico efectuados há a destacar: hemoglobina 4.7mg/dL; volume globular médio (VGM) 124fL; hemoglobina globular média (HGM) 45.3pg; leucócitos 1900µL; plaquetas 4300 µL, lactato desidrogenase 1851UI/L; híperbilirubinemia indirecta de 1.6mg/dL , ácido fólico < 1ng/mL (3-17); doseamento de vitamina B12 207pg/mL (139-928) e ferro sérico 272mcg/dL (35-150). Realizou tomografia computorizada tóraco-abdominó-pélvica que não revelou alterações. Excluíram-se doenças neoplásicas e infecção pelos vírus da imunodeficiência humana, vírus da hepatite B e C. Iniciou reposição de ácido fólico, tendo-se verificado normalização das alterações analíticas e regressão completa da hiperpigmentação. Teve alta clinica ao 11º dia de internamento, apresentando: hemoglobina 9.6mg/dL; VGM 98.3fL; leucócitos 4600µL; plaquetas 472.000µL e doseamento de ácido fólico 37.5ng/mL

    Towards high-speed optical quantum memories

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    Quantum memories, capable of controllably storing and releasing a photon, are a crucial component for quantum computers and quantum communications. So far, quantum memories have operated with bandwidths that limit data rates to MHz. Here we report the coherent storage and retrieval of sub-nanosecond low intensity light pulses with spectral bandwidths exceeding 1 GHz in cesium vapor. The novel memory interaction takes place via a far off-resonant two-photon transition in which the memory bandwidth is dynamically generated by a strong control field. This allows for an increase in data rates by a factor of almost 1000 compared to existing quantum memories. The memory works with a total efficiency of 15% and its coherence is demonstrated by directly interfering the stored and retrieved pulses. Coherence times in hot atomic vapors are on the order of microsecond - the expected storage time limit for this memory.Comment: 13 pages, 5 figure

    Physical mapping integrated with syntenic analysis to characterize the gene space of the long arm of wheat chromosome 1A

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    Background: Bread wheat (Triticum aestivum L.) is one of the most important crops worldwide and its production faces pressing challenges, the solution of which demands genome information. However, the large, highly repetitive hexaploid wheat genome has been considered intractable to standard sequencing approaches. Therefore the International Wheat Genome Sequencing Consortium (IWGSC) proposes to map and sequence the genome on a chromosome-by-chromosome basis. Methodology/Principal Findings: We have constructed a physical map of the long arm of bread wheat chromosome 1A using chromosome-specific BAC libraries by High Information Content Fingerprinting (HICF). Two alternative methods (FPC and LTC) were used to assemble the fingerprints into a high-resolution physical map of the chromosome arm. A total of 365 molecular markers were added to the map, in addition to 1122 putative unique transcripts that were identified by microarray hybridization. The final map consists of 1180 FPC based or 583 LTC based contigs. Conclusions/Significance: The physical map presented here marks an important step forward in mapping of hexaploid bread wheat. The map is orders of magnitude more detailed than previously available maps of this chromosome, and the assignment of over a thousand putative expressed gene sequences to specific map locations will greatly assist future functional studies. This map will be an essential tool for future sequencing of and positional cloning within chromosome 1A

    Unique and conserved MicroRNAs in wheat chromosome 5D revealed by next-generation sequencing

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    MicroRNAs are a class of short, non-coding, single-stranded RNAs that act as post-transcriptional regulators in gene expression. miRNA analysis of Triticum aestivum chromosome 5D was performed on 454 GS FLX Titanium sequences of flow sorted chromosome 5D with a total of 3,208,630 good quality reads representing 1.34x and 1.61x coverage of the short (5DS) and long (5DL) arms of the chromosome respectively. In silico and structural analyses revealed a total of 55 miRNAs; 48 and 42 miRNAs were found to be present on 5DL and 5DS respectively, of which 35 were common to both chromosome arms, while 13 miRNAs were specific to 5DL and 7 miRNAs were specific to 5DS. In total, 14 of the predicted miRNAs were identified in wheat for the first time. Representation (the copy number of each miRNA) was also found to be higher in 5DL (1,949) compared to 5DS (1,191). Targets were predicted for each miRNA, while expression analysis gave evidence of expression for 6 out of 55 miRNAs. Occurrences of the same miRNAs were also found in Brachypodium distachyon and Oryza sativa genome sequences to identify syntenic miRNA coding sequences. Based on this analysis, two other miRNAs: miR1133 and miR167 were detected in B. distachyon syntenic region of wheat 5DS. Five of the predicted miRNA coding regions (miR6220, miR5070, miR169, miR5085, miR2118) were experimentally verified to be located to the 5D chromosome and three of them : miR2118, miR169 and miR5085, were shown to be 5D specific. Furthermore miR2118 was shown to be expressed in Chinese Spring adult leaves. miRNA genes identified in this study will expand our understanding of gene regulation in bread wheat

    Electroexcitation of the Δ+(1232)\Delta^{+}(1232) at low momentum transfer

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    We report on new p(e,e′p)π∘(e,e^\prime p)\pi^\circ measurements at the Δ+(1232)\Delta^{+}(1232) resonance at the low momentum transfer region. The mesonic cloud dynamics is predicted to be dominant and rapidly changing in this kinematic region offering a test bed for chiral effective field theory calculations. The new data explore the low Q2Q^2 dependence of the resonant quadrupole amplitudes while extending the measurements of the Coulomb quadrupole amplitude to the lowest momentum transfer ever reached. The results disagree with predictions of constituent quark models and are in reasonable agreement with dynamical calculations that include pion cloud effects, chiral effective field theory and lattice calculations. The reported measurements suggest that improvement is required to the theoretical calculations and provide valuable input that will allow their refinements

    A Search for Sigma^0_5, N^0_5 and Theta^++ Pentaquark States

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    A high-resolution (sigma_instr. = 1.5 MeV) search for narrow states (Gamma < 10 MeV) with masses of M_x approx 1500-1850 MeV in ep -> e'K^+ X, e'K^- X and e' pi^+ X electroproduction at small angles and low Q^2 was performed. These states would be candidate partner states of the reported Theta^+(1540) pentaquark. No statistically significant signal was observed in any of the channels at 90% C.L. Upper limits on forward production were determined to be between 0.7% and 4.2% of the Lambda(1520) production cross section, depending on the channel and the assumed mass and width of the state.Comment: 5 pages, 5 figures, to appear in Phys. Rev. C, update with responses to referee suggestion

    CUORE and beyond: bolometric techniques to explore inverted neutrino mass hierarchy

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    The CUORE (Cryogenic Underground Observatory for Rare Events) experiment will search for neutrinoless double beta decay of 130^{130}Te. With 741 kg of TeO2_2 crystals and an excellent energy resolution of 5 keV (0.2%) at the region of interest, CUORE will be one of the most competitive neutrinoless double beta decay experiments on the horizon. With five years of live time, CUORE projected neutrinoless double beta decay half-life sensitivity is 1.6×10261.6\times 10^{26} y at 1σ1\sigma (9.5×10259.5\times10^{25} y at the 90% confidence level), which corresponds to an upper limit on the effective Majorana mass in the range 40--100 meV (50--130 meV). Further background rejection with auxiliary light detector can significantly improve the search sensitivity and competitiveness of bolometric detectors to fully explore the inverted neutrino mass hierarchy with 130^{130}Te and possibly other double beta decay candidate nuclei.Comment: Submitted to the Proceedings of TAUP 2013 Conferenc

    Exploring the Neutrinoless Double Beta Decay in the Inverted Neutrino Hierarchy with Bolometric Detectors

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    Neutrinoless double beta decay (0nubb) is one of the most sensitive probes for physics beyond the Standard Model, providing unique information on the nature of neutrinos. In this paper we review the status and outlook for bolometric 0nubb decay searches. We summarize recent advances in background suppression demonstrated using bolometers with simultaneous readout of heat and light signals. We simulate several configurations of a future CUORE-like bolometer array which would utilize these improvements and present the sensitivity reach of a hypothetical next-generation bolometric 0nubb experiment. We demonstrate that a bolometric experiment with the isotope mass of about 1 ton is capable of reaching the sensitivity to the effective Majorana neutrino mass (|mee|) of order 10-20 meV, thus completely exploring the so-called inverted neutrino mass hierarchy region. We highlight the main challenges and identify priorities for an R&D program addressing them.Comment: 22 pages, 15 figures, submitted to EPJ
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