350 research outputs found
PO-0970: Assessment of regional positional repeatability in head and neck using a dedicated MR simulator
Discordant severity criteria in patients with moderate aortic stenosis: prognostic implications
Background The criteria to define the grade of aortic stenosis (AS)-aortic valve area (AVA) and mean gradient (MG) or peak jet velocity-do not always coincide into one grade. Although in severe AS, this discrepancy is well characterised, in moderate AS, the phenomenon of discordant grading has not been investigated and its prognostic implications are unknown.Objectives To investigate the occurrence of discordant grading in patients with moderate AS (defined by an AVA between 1.0 cm(2) and 1.5 cm(2) but with an MG = 20 mm Hg) in terms of clinical outcomes.Methods From an ongoing registry of patients with AS, patients with moderate AS based on AVA were selected and classified into discordant or concordant grading (MG = 20 mm Hg, respectively). The clinical endpoint was all-cause mortality.Results Of 790 patients with moderate AS, 150 (19.0%) had discordant grading, moderate AS. Patients with discordant grading were older, had higher prevalence of previous myocardial infarction and left ventricular (LV) hypertrophy, larger LV end-diastolic and end-systolic volume index, higher LV filling pressure and lower LV ejection fraction and stroke volume index as compared with their counterparts. After a median follow-up of 4.9 years (IQR 3.0-8.2), patients with discordant grading had lower aortic valve replacement rates (26.7% vs 44.1%, p<0.001) and higher mortality rates (60.0% vs 43.1%, p<0.001) as compared with patients with concordant grading. Discordant grading moderate AS, combined with low LV ejection fraction, presented the higher risk of mortality (HR 2.78 (2.00-3.87), p<0.001).Conclusion Discordant-grading moderate AS is not uncommon and, when combined with low LV ejection fraction, is associated with high risk of mortality.Cardiolog
Excited states in 155Yb and 155,156,157 Lu from recoil-decay tagging
The 270-MeV 58Ni+ 102Pd reaction was used for the first recoil-decay tagging measurement with Gamma-sphere coupled to the Fragment Mass Analyzer at Argonne National Laboratory. Level structures of 155Yb, 156Lu, and 157Lu, as well as the excited states associated with the 25/2- isomer in 155Lu, are identified for the first time. The systematical behavior of the energy levels is compared with that of neighboring isotones and isotopes. The attractive interaction between h11/2 protons and h9/2 neutrons plays an important role in the structure of 155Yb and 155,156Lu
High-spin excitations in 158,159,160Hf from recoil-decay tagging
The 270-MeV 58Ni+ APd reaction was used for the first recoil-decay tagging measurement with Gammasphere coupled to the Fragment Mass Analyzer at Argonne National Laboratory. Level structures of 158Hf and 159Hf are identified for the first time, and that of 160Hf is extended. The systematical behavior of the energy levels in neighboring isotones and isotopes, as well as the aligned angular momenta as a function of rotational frequency, are examined
Multiparticle configurations in N=84 isotones located at the proton drip line
Excited states in the proton-rich N=84 isotones 72156Hf84,73157Ta84, and 74158W84 were observed using Pd102(Ni58,xp2n) reactions at 270 MeV. γ rays were detected with the Gammasphere array of Compton-suppressed Ge detectors coupled with the Argonne fragment mass analyzer and were assigned to individual reaction channels using the recoil-decay tagging method. Prompt γ-ray cascades were associated with the α decay of both the ground state and the 8+ isomeric state in Hf156, the h11/2 state in Ta157, and the 8+ isomeric state in W158. The level schemes constructed for Hf156,Ta157, and W158 are compared with these of lighter N=84 isotones and are discussed within the framework of the shell model
Heavy quarkonium: progress, puzzles, and opportunities
A golden age for heavy quarkonium physics dawned a decade ago, initiated by
the confluence of exciting advances in quantum chromodynamics (QCD) and an
explosion of related experimental activity. The early years of this period were
chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in
2004, which presented a comprehensive review of the status of the field at that
time and provided specific recommendations for further progress. However, the
broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles
could only be partially anticipated. Since the release of the YR, the BESII
program concluded only to give birth to BESIII; the -factories and CLEO-c
flourished; quarkonium production and polarization measurements at HERA and the
Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the
deconfinement regime. All these experiments leave legacies of quality,
precision, and unsolved mysteries for quarkonium physics, and therefore beg for
continuing investigations. The plethora of newly-found quarkonium-like states
unleashed a flood of theoretical investigations into new forms of matter such
as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the
spectroscopy, decays, production, and in-medium behavior of c\bar{c}, b\bar{b},
and b\bar{c} bound states have been shown to validate some theoretical
approaches to QCD and highlight lack of quantitative success for others. The
intriguing details of quarkonium suppression in heavy-ion collisions that have
emerged from RHIC have elevated the importance of separating hot- and
cold-nuclear-matter effects in quark-gluon plasma studies. This review
systematically addresses all these matters and concludes by prioritizing
directions for ongoing and future efforts.Comment: 182 pages, 112 figures. Editors: N. Brambilla, S. Eidelman, B. K.
Heltsley, R. Vogt. Section Coordinators: G. T. Bodwin, E. Eichten, A. D.
Frawley, A. B. Meyer, R. E. Mitchell, V. Papadimitriou, P. Petreczky, A. A.
Petrov, P. Robbe, A. Vair
Spectroscopy of 193,195,197Po
Excited states built on the 13/21 isomers of the odd-mass 193,195,197Po isotopes have been observed via in-beam g-ray spectroscopy. The a radioactivity of these isotopes has been used to tag g -ray transitions following the AEr1164 MeV 32S reactions, where A5164, 166, 167, 168, and 170. Prompt g radiation was measured by ten Compton-suppressed Ge detectors at the target position and the Fragment Mass Analyzer was used to select evaporation residues. The results are compared with the first excited states of the heavier odd-mass polonium isotopes and of the even-mass cores
Rotational bands in the proton emitter 141Ho
The rotational bands feeding the ground state and the isomeric state in the proton emitter 141Ho are presented using the recoil-decay tagging method. A quadrupole deformation of β2 = 0.25(4) was deduced for the ground state band. The observed band crossings and signature splittings agreed with the configurational assignments for the ground state and the isomer analyzed from the proton-decay rates
Ground-state band and deformation of the Z=102 isotope 254No
The ground-state band of the Z=102 isotope 254No has been identified up to spin 14, indicating that the nucleus is deformed. The deduced quadrupole deformation, β=0.27, is in agreement with theoretical predictions. These observations confirm that the shell-correction energy responsible for the stability of transfermium nuclei is partly derived from deformation. The survival of 254No up to spin 14 means that its fission barrier persists at least up to that spin
Orientation dependence in molecular dynamics simulations of shocked single crystals
The entry distribution in angular momentum and excitation energy for the formation of 254No has been measured after the 208Pb reaction at 215 and 219 MeV. This nucleus is populated up to spin 22h and excitation energy >˜6 MeV above the yrast line, with the half-maximum points of the energy distributions at ˜5 MeV for spins between 12h and 22h. This suggests that the fission barrier is >˜5 MeV and that the shell-correction energy persists to high spin
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