469 research outputs found
Tricks Of The Trade [pulo Do Gato]
[No abstract available]704245Hoch, W., McConville, J., Helms, S., Newsom-Davis, J., Melms, A., Vincent, A., Auto-antibodies to the receptor tyrosine kinase MuSK in patients with myasthenia gravis without acetylcholine receptor antibodies (2001) Nat Med, 7, pp. 365-368Leite, M.I., Jacob, S., Viegas, S., IgG1 antibodies to acetylcholine receptors in 'seronegative' myasthenia gravis (2008) Brain, 131, pp. 1940-1952Barber, P.A., Anderson, N.E., Vincent, A., Morvan's syndrome associated with voltage-gated K+ channel antibodies (2000) Neurology, 54, pp. 771-772Liguori, R., Vincent, A., Clover, L., Morvan's syndrome: Peripheral and central nervous system and cardiac involvement with antibodies to voltage-gated potassium channels (2001) Brain, 124, pp. 2417-2426Vincent, A., Buckley, C., Schott, J.M., Potassium channel antibody-associated encephalopathy: A potentially immunotherapy-responsive form of limbic encephalitis (2004) Brain, 127, pp. 701-712Irani, S.R., Alexander, S., Waters, P., Antibodies to Kv1 potassium channel-complex proteins leucine-rich, glioma inactivated 1 protein and contactin-associated protein-2 in limbic encephalitis, Morvan's syndrome and acquired neuromyotonia (2010) Brain, 133, pp. 2734-2748Hutchinson, M., Waters, P., McHugh, J., Progressive encephalomyelitis, rigidity, and myoclonus: A novel glycine receptor antibody (2008) Neurology, 71, pp. 1291-129
Antihydrogen formation dynamics in a multipolar neutral anti-atom trap
Antihydrogen production in a neutral atom trap formed by an octupole-based
magnetic field minimum is demonstrated using field-ionization of weakly bound
anti-atoms. Using our unique annihilation imaging detector, we correlate
antihydrogen detection by imaging and by field-ionization for the first time.
We further establish how field-ionization causes radial redistribution of the
antiprotons during antihydrogen formation and use this effect for the first
simultaneous measurements of strongly and weakly bound antihydrogen atoms.
Distinguishing between these provides critical information needed in the
process of optimizing for trappable antihydrogen. These observations are of
crucial importance to the ultimate goal of performing CPT tests involving
antihydrogen, which likely depends upon trapping the anti-atom
Search For Trapped Antihydrogen
We present the results of an experiment to search for trapped antihydrogen
atoms with the ALPHA antihydrogen trap at the CERN Antiproton Decelerator.
Sensitive diagnostics of the temperatures, sizes, and densities of the trapped
antiproton and positron plasmas have been developed, which in turn permitted
development of techniques to precisely and reproducibly control the initial
experimental parameters. The use of a position-sensitive annihilation vertex
detector, together with the capability of controllably quenching the
superconducting magnetic minimum trap, enabled us to carry out a
high-sensitivity and low-background search for trapped synthesised antihydrogen
atoms. We aim to identify the annihilations of antihydrogen atoms held for at
least 130 ms in the trap before being released over ~30 ms. After a three-week
experimental run in 2009 involving mixing of 10^7 antiprotons with 1.3 10^9
positrons to produce 6 10^5 antihydrogen atoms, we have identified six
antiproton annihilation events that are consistent with the release of trapped
antihydrogen. The cosmic ray background, estimated to contribute 0.14 counts,
is incompatible with this observation at a significance of 5.6 sigma. Extensive
simulations predict that an alternative source of annihilations, the escape of
mirror-trapped antiprotons, is highly unlikely, though this possibility has not
yet been ruled out experimentally.Comment: 12 pages, 7 figure
Numerical approach for assessing combustion noise in compression-ignited Diesel engines
[EN] Diesel combustion noise has become a crucial aspect for the engine manufacturers due to its impact on human health and influence on the customer purchasing decision. The interaction of the pressure waves after mixture self-ignition induces cavity resonances inside the combustion chamber. This complex phenomenon produces high-frequency pressure oscillations, hence traditional in-cylinder measurements do not provide enough information to characterise the in-cylinder acoustic field. In this paper, a numerical methodology is proposed for assessing the Diesel combustion as a noise source and to overcome measurement limitations. An optimisation procedure is also presented in order to determine the numerical calculation parameters, boundary conditions definition and initialization. Results show that local flow conditions at the start of combustion have a strong influence on the acoustic response of the in-cylinder noise source. These particular conditions are only achievable by the proposed methodology which considers entire engine cycle simulations with the complete cylinder domain. Therefore, traditional Computational Fluid Dynamic (CFD) approaches, such those used for predicting combustion stability or pollutant emissions, are not suitable for reproducing the physical mechanisms of noise generation and they cannot be used for acoustic purposes. The reliability of the proposed methodology to simulate the acoustic field accurately inside the combustion chamber has been validated by comparison with experiments.The equipment used in this work has been partially supported by FEDER project funds "Dotacion de infraestructuras cientifico tecnicas para el Centro Integral de Mejora Energdtica y Medioambiental de Sistemas de Transporte (CiMeT), (FEDER-ICTS-2012-06)", framed in the operational program of unique scientific and technical infrastructure of the Spanish Ministerio de Economia y Competitividad.
J. Gomez-Soriano is partially supported through the "Programa de Apoyo para la Investigacion y Desarrollo (PAID)" of Universitat Politecnica de Valencia [Grant No. FPI-S2-2016-1353].Torregrosa, AJ.; Broatch, A.; Gil, A.; Gómez-Soriano, J. (2018). Numerical approach for assessing combustion noise in compression-ignited Diesel engines. Applied Acoustics. 135:91-100. https://doi.org/10.1016/j.apacoust.2018.02.006S9110013
An Integrated TCGA Pan-Cancer Clinical Data Resource to Drive High-Quality Survival Outcome Analytics
For a decade, The Cancer Genome Atlas (TCGA) program collected clinicopathologic annotation data along with multi-platform molecular profiles of more than 11,000 human tumors across 33 different cancer types. TCGA clinical data contain key features representing the democratized nature of the data collection process. To ensure proper use of this large clinical dataset associated with genomic features, we developed a standardized dataset named the TCGA Pan-Cancer Clinical Data Resource (TCGA-CDR), which includes four major clinical outcome endpoints. In addition to detailing major challenges and statistical limitations encountered during the effort of integrating the acquired clinical data, we present a summary that includes endpoint usage recommendations for each cancer type. These TCGA-CDR findings appear to be consistent with cancer genomics studies independent of the TCGA effort and provide opportunities for investigating cancer biology using clinical correlates at an unprecedented scale. Analysis of clinicopathologic annotations for over 11,000 cancer patients in the TCGA program leads to the generation of TCGA Clinical Data Resource, which provides recommendations of clinical outcome endpoint usage for 33 cancer types
SEM analysis of ion implanted SiC
SiC is a material used in two future energy production technologies, firstly as a photovoltaic layer to harness
the UV spectrum in high efficient power solar cells, and secondly as a diffusion barrier material for
radioactive fission products in the fuel elements of the next generation of nuclear power plants. For both
applications, there is an interest in the implantation of reactive and non-reactive ions into SiC and their
effects on the properties of the SiC. In this study 360 keV Ag+, I+ and Xe+ ions were separately implanted
into 6H–SiC and in polycrystalline SiC at various substrate temperatures. The implanted samples were
also annealed in vacuum at temperatures ranging from 900 C to 1600 C for various times. In recent
years, there had been significant advances in scanning electron microscopy (SEM) with the introduction
of an in-lens detector combined with field emission electron guns. This allows defects in solids, such as
radiation damage created by the implanted ions, to be detected with SEM. Cross-sectional SEM images of
6H–SiC wafers implanted with 360 keV Ag+ ions at room temperature and at 600 C and then vacuum
annealed at different temperatures revealed the implanted layers and their thicknesses. A similar result
is shown of 360 keV I+ ions implanted at 600 C into 6H–SiC and annealed at 1600 C. The 6H–SiC is not
amorphized but remained crystalline when implanting at 600 C. There are differences in the microstructure
of 6H–SiC implanted with silver at the two temperatures as well as with reactive iodine ions. Voids
(bubbles) are created in the implanted layers into which the precipitation of silver and iodine can occur
after annealing of the samples. The crystallinity of the substrate via implantation temperature caused differences
in the distribution and size of the voids. Implantation of xenon ions in polycrystalline SiC at
350 C does not amorphize the substrate as is the case with room temperature heavy ion bombardment.
Subsequent annealing of the implanted polycrystalline samples leads to increased thermal etching effects
such as grain boundary grooving. Damage due to channelling (or non-channelling) in the different crystallites
resulted also in differences in thermal etching in the crystallites.http://www.elsevier.com/locate/nimbhb201
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