1,369 research outputs found
Phlebotomy in the Treatment of Iron Overload in Patients with Nonalcoholic and Alcoholic Fatty Liver Diseases
Abstract In patients with chronic liver disease, especially nonalcoholic fatty liver disease (NAFLD) was also found in the three groups of patients. In patients with NAFLD, a decrease of serum insulin on fasting post phlebotomies, р = 0.005
45S rDNA external transcribed spacer organization reveals new phylogenetic relationships in Avena genus
Research ArticleThe genus Avena comprises four distinct genomes organized in diploid (AA or CC), tetraploid
(AABB or AACC) and hexaploid species (AACCDD), constituting an interesting model
for phylogenetic analysis. The aim of this work was to characterize 45S rDNA intergenic
spacer (IGS) variability in distinct species representative of Avena genome diversity±A.
strigosa (AA), A. ventricosa (CvCv), A. eriantha (CpCp), A. barbata (AABB), A. murphyi
(AACC), A. sativa (AACCDD) and A. sterilis (AACCDD) through the assessment of the 5'
external transcribed spacer (5'-ETS), a promising IGS region for phylogenetic studies poorly
studied in Avena genus. In this work, IGS length polymorphisms were detected mainly due
to distinct 5'-ETS sequence types resulting from major differences in the number and organization
of repeated motifs. Although species with A genome revealed a 5'-ETS organization
(A-organization) similar to the one previously described in A. sativa, a distinct organization
was unraveled in C genome diploid species (C-organization). Interestingly, such new organization
presents a higher similarity with other Poaceae species than A-genome sequences,
supporting the hypothesis of C-genome being the ancestral Avena genome. Additionally,
polyploid species with both genomes mainly retain the A-genome 5'-ETS organization, confirming
the preferential elimination of C-genome sequences in Avena polyploid species.
Moreover, 5'-ETS sequences phylogenetic analysis consistently clustered the species studied
according to ploidy and genomic constitution supporting the use of ribosomal genes to
highlight Avena species evolutive pathways.info:eu-repo/semantics/publishedVersio
On the Deformation of Dendrites During Directional Solidification of a Nickel-Based Superalloy
Abstract: Synchrotron X-ray imaging has been used to examine in situ the deformation of dendrites that takes place during the solidification of a nickel-based superalloy. By combining absorption and diffraction contrast imaging, deformation events could be classified by their localization and permanence. In particular, a deformation mechanism arising from thermal contraction in a temperature gradient was elucidated through digital image correlation. It was concluded that this mechanism may explain the small misorientations typically observed in single crystal castings
Differential tt¯cross-section measurements using boosted top quarks in the all-hadronic final state with 139 fb−1 of ATLAS data
Measurements of single-, double-, and triple-differential cross-sections are presented for boosted top-quark pair-production in 13 TeV proton–proton collisions recorded by the ATLAS detector at the LHC. The top quarks are observed through their hadronic decay and reconstructed as large-radius jets with the leading jet having transverse momentum (pT) greater than 500 GeV. The observed data are unfolded to remove detector effects. The particle-level cross-section, multiplied by the tt¯ → WWbb¯ branching fraction and measured in a fiducial phase space defined by requiring the leading and second-leading jets to have pT> 500 GeV and pT> 350 GeV, respectively, is 331 ± 3(stat.) ± 39(syst.) fb. This is approximately 20% lower than the prediction of 398−49+48 fb by Powheg+Pythia 8 with next-to-leading-order (NLO) accuracy but consistent within the theoretical uncertainties. Results are also presented at the parton level, where the effects of top-quark decay, parton showering, and hadronization are removed such that they can be compared with fixed-order next-to-next-to-leading-order (NNLO) calculations. The parton-level cross-section, measured in a fiducial phase space similar to that at particle level, is 1.94 ± 0.02(stat.) ± 0.25(syst.) pb. This agrees with the NNLO prediction of 1.96−0.17+0.02 pb. Reasonable agreement with the differential cross-sections is found for most NLO models, while the NNLO calculations are generally in better agreement with the data. The differential cross-sections are interpreted using a Standard Model effective field-theory formalism and limits are set on Wilson coefficients of several four-fermion operators. [Figure not available: see fulltext.]
Search for top-philic heavy resonances in pp collisions at s=13Â TeV with the ATLAS detector
A search for the associated production of a heavy resonance with a top-quark or a top-antitop-quark pair, and decaying into a tt¯ pair is presented. The search uses the data recorded by the ATLAS detector in pp collisions at s=13 TeV at the Large Hadron Collider during the years 2015–2018, corresponding to an integrated luminosity of 139 fb-1. Events containing exactly one electron or muon are selected. The two hadronically decaying top quarks from the resonance decay are reconstructed using jets clustered with a large radius parameter of R=1. The invariant mass spectrum of the two top quark candidates is used to search for a resonance signal in the range of 1.0 TeV to 3.2 TeV. The presence of a signal is examined using an approach with minimal model dependence followed by a model-dependent interpretation. No significant excess is observed over the background expectation. Upper limits on the production cross section times branching ratio at 95% confidence level are provided for a heavy Z′ boson based on a simplified model, for Z′ mass between 1.0 TeV and 3.0 TeV. The observed (expected) limits range from 21 (14) fb to 119 (86) fb depending on the choice of model parameters
Combination of searches for invisible decays of the Higgs boson using 139 fb−1 of proton-proton collision data at √s = 13 TeV collected with the ATLAS experiment
Many extensions of the Standard Model predict the production of dark matter particles at the LHC.
Sufficiently light dark matter particles may be produced in decays of the Higgs boson that would
appear invisible to the detector. This Letter presents a statistical combination of searches for H →
invisible decays where multiple production modes of the Standard Model Higgs boson are considered.
These searches are performed with the ATLAS detector using 139 fb−1 of proton–proton collisions at a
centre–of–mass energy of √s = 13 TeV at the LHC. In combination with the results at √s = 7 TeV and
8 TeV, an upper limit on the H → invisible branching ratio of 0.107 (0.077) at the 95% confidence level
is observed (expected). These results are also interpreted in the context of models where the 125 GeV
Higgs boson acts as a portal to dark matter, and limits are set on the scattering cross-section of weakly
interacting massive particles and nucleons
Searches for lepton-flavour-violating decays of the Higgs boson into eτ and μτ in √s = 13 TeV pp collisions with the ATLAS detector
This paper presents direct searches for lepton flavour violation in Higgs boson decays, H → eτ and H → μτ, performed using data collected with the ATLAS detector at the LHC. The searches are based on a data sample of proton-proton collisions at a centre-of-mass energy s = 13 TeV, corresponding to an integrated luminosity of 138 fb −1. Leptonic (τ → ℓνℓ ντ) and hadronic (τ → hadrons ντ) decays of the τ-lepton are considered. Two background estimation techniques are employed: the MC-template method, based on data-corrected simulation samples, and the Symmetry method, based on exploiting the symmetry between electrons and muons in the Standard Model backgrounds. No significant excess of events is observed and the results are interpreted as upper limits on lepton-flavour-violating branching ratios of the Higgs boson. The observed (expected) upper limits set on the branching ratios at 95% confidence level, B (H → eτ) < 0.20% (0.12%) and B (H → μτ) < 0.18% (0.09%), are obtained with the MC-template method from a simultaneous measurement of potential H → eτ and H → μτ signals. The best-fit branching ratio difference, B (H → μτ) → B (H → eτ), measured with the Symmetry method in the channel where the τ-lepton decays to leptons, is (0.25 ± 0.10)%, compatible with a value of zero within 2.5σ. [Figure not available: see fulltext.]
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Differential cross-section measurements of the production of four charged leptons in association with two jets using the ATLAS detector
Differential cross-sections are measured for the production of four charged leptons in association with two jets. These measurements are sensitive to final states in which the jets are produced via the strong interaction as well as to the purely-electroweak vector boson scattering process. The analysis is performed using proton-proton collision data collected by ATLAS at s = 13 TeV and with an integrated luminosity of 140 fb−1. The data are corrected for the effects of detector inefficiency and resolution and are compared to state-of-the-art Monte Carlo event generator predictions. The differential cross-sections are used to search for anomalous weak-boson self-interactions that are induced by dimension-six and dimension-eight operators in Standard Model effective field theory
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Search for direct production of electroweakinos in final states with one lepton, jets and missing transverse momentum in pp collisions at s = 13 TeV with the ATLAS detector
Searches for electroweak production of wino-like chargino pairs, χ~1+χ~1−, and of wino-like chargino and next-to-lightest neutralino, χ~1±χ~20, are presented. The models explored assume that the charginos decay into a W boson and the lightest neutralino, χ~1±→W±χ~10. The next-to-lightest neutralinos are degenerate in mass with the chargino and decay to χ~10 and either a Z or a Higgs boson, χ~20→Zχ~10 or hχ~10. The searches exploit the presence of a single isolated lepton and missing transverse momentum from the W boson decay products and the lightest neutralinos, and the presence of jets from hadronically decaying Z or W bosons or from the Higgs boson decaying into a pair of b-quarks. The searches use 139 fb−1 of (Formula presented.) TeV proton-proton collisions data collected by the ATLAS detector at the Large Hadron Collider between 2015 and 2018. No deviations from the Standard Model expectations are found, and 95% confidence level exclusion limits are set. Chargino masses ranging from 260 to 520 GeV are excluded for a massless χ~10 in chargino pair production models. Degenerate chargino and next-to-lightest neutralino masses ranging from 260 to 420 GeV are excluded for a massless χ~10 for χ~20→Zχ~10. For decays through an on-shell Higgs boson and for mass-splitting between χ~1±/χ~20 and χ~10 as small as the Higgs boson mass, mass limits are improved by up to 40 GeV in the range of 200–260 GeV and 280–470 GeV compared to previous ATLAS constraints
Production of Ï’(nS) mesons in Pb + Pb and pp collisions at 5.02 TeV
A measurement of the production of vector bottomonium states, ϒ(1S), ϒ(2S), and ϒ(3S), in Pb + Pb and pp collisions at a center-of-mass energy per nucleon pair of 5.02 TeV is presented. The data correspond to integrated luminosities of 1.38 nb-1 of Pb + Pb data collected in 2018, 0.44 nb-1 of Pb + Pb data collected in 2015, and 0.26 fb-1 of pp data collected in 2017 by the ATLAS detector at the Large Hadron Collider. The measurements are performed in the dimuon decay channel for transverse momentum pμμT < 30 GeV, absolute rapidity |yμμ| < 1.5, and Pb + Pb event centrality 0-80%. The production rates of the three bottomonium states in Pb + Pb collisions are compared with those in pp collisions to extract the nuclear modification factors as functions of event centrality, pμμT, and |yμμ|. In addition, the suppression of the excited states relative to the ground state is studied. The results are compared with theoretical model calculations
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