5,884 research outputs found
AVC isquémico em doente jovem - caso clÃnico
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 possÃvel 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 carotÃdeo, Holter, punção lombar com exame citoquÃmico e bacteriológico do lÃquido 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 compatÃveis com lesões lacunares na região frontal bilateral. Realizou ecocardiogramas transtorácico e transesofágico que revelaram solução de continuidade compatÃvel 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
A anemia carêncial é uma uma patologia pouco prevalente na sociedade actual, acometendo uma população com caracterÃsticas muito especÃficas. 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 clÃnico 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; hÃperbilirubinemia 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. ExcluÃram-se doenças neoplásicas e infecção pelos vÃrus da imunodeficiência humana, vÃrus da hepatite B e C. Iniciou reposição de ácido fólico, tendo-se verificado normalização das alterações analÃticas 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
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
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
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 at low momentum transfer
We report on new p measurements at the
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 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
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
The CUORE (Cryogenic Underground Observatory for Rare Events) experiment will
search for neutrinoless double beta decay of Te. With 741 kg of TeO
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 y
at ( 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 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
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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