| 1. |
- Abelev, Betty, et al.
(författare)
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Underlying Event measurements in pp collisions at root s=0.9 and 7 TeV with the ALICE experiment at the LHC
- 2012
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Ingår i: Journal of High Energy Physics. - 1029-8479. ; :7
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Tidskriftsartikel (refereegranskat)abstract
- We present measurements of Underlying Event observables in pp collisions at root s = 0 : 9 and 7 TeV. The analysis is performed as a function of the highest charged-particle transverse momentum p(T),L-T in the event. Different regions are defined with respect to the azimuthal direction of the leading (highest transverse momentum) track: Toward, Transverse and Away. The Toward and Away regions collect the fragmentation products of the hardest partonic interaction. The Transverse region is expected to be most sensitive to the Underlying Event activity. The study is performed with charged particles above three different p(T) thresholds: 0.15, 0.5 and 1.0 GeV/c. In the Transverse region we observe an increase in the multiplicity of a factor 2-3 between the lower and higher collision energies, depending on the track p(T) threshold considered. Data are compared to PYTHIA 6.4, PYTHIA 8.1 and PHOJET. On average, all models considered underestimate the multiplicity and summed p(T) in the Transverse region by about 10-30%.
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| 2. |
- Abelev, Betty, et al.
(författare)
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Long-range angular correlations on the near and away side in p-Pb collisions at root S-NN=5.02 TeV
- 2013
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 719:1-3, s. 29-41
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Tidskriftsartikel (refereegranskat)abstract
- Angular correlations between charged trigger and associated particles are measured by the ALICE detector in p-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV for transverse momentum ranges within 0.5 < P-T,P-assoc < P-T,P-trig < 4 GeV/c. The correlations are measured over two units of pseudorapidity and full azimuthal angle in different intervals of event multiplicity, and expressed as associated yield per trigger particle. Two long-range ridge-like structures, one on the near side and one on the away side, are observed when the per-trigger yield obtained in low-multiplicity events is subtracted from the one in high-multiplicity events. The excess on the near-side is qualitatively similar to that recently reported by the CMS Collaboration, while the excess on the away-side is reported for the first time. The two-ridge structure projected onto azimuthal angle is quantified with the second and third Fourier coefficients as well as by near-side and away-side yields and widths. The yields on the near side and on the away side are equal within the uncertainties for all studied event multiplicity and p(T) bins, and the widths show no significant evolution with event multiplicity or p(T). These findings suggest that the near-side ridge is accompanied by an essentially identical away-side ridge. (c) 2013 CERN. Published by Elsevier B.V. All rights reserved.
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| 3. |
- Abelev, Betty, et al.
(författare)
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Measurement of prompt J/psi and beauty hadron production cross sections at mid-rapidity in pp collisions at root s=7 TeV
- 2012
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Ingår i: Journal of High Energy Physics. - 1029-8479. ; :11
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Tidskriftsartikel (refereegranskat)abstract
- The ALICE experiment at the LHC has studied J/psi production at mid-rapidity in pp collisions at root s = 7 TeV through its electron pair decay on a data sample corresponding to an integrated luminosity L-int = 5.6 nb(-1). The fraction of J/psi from the decay of long-lived beauty hadrons was determined for J/psi candidates with transverse momentum p(t) > 1,3 GeV/c and rapidity vertical bar y vertical bar < 0.9. The cross section for prompt J/psi mesons, i.e. directly produced J/psi and prompt decays of heavier charmonium states such as the psi(2S) and chi(c) resonances, is sigma(prompt J/psi) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 8.3 +/- 0.8(stat.) +/- 1.1 (syst.)(-1.4)(+1.5) (syst. pol.) mu b. The cross section for the production of b-hadrons decaying to J/psi with p(t) > 1.3 GeV/c and vertical bar y vertical bar < 0.9 is a sigma(J/psi <- hB) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 1.46 +/- 0.38 (stat.)(-0.32)(+0.26) (syst.) mu b. The results are compared to QCD model predictions. The shape of the p(t) and y distributions of b-quarks predicted by perturbative QCD model calculations are used to extrapolate the measured cross section to derive the b (b) over bar pair total cross section and d sigma/dy at mid-rapidity.
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| 4. |
- De Marco, Marina, et al.
(författare)
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Mitral annular calcification and incident ischemic stroke in treated hypertensive patients : the LIFE study
- 2013
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Ingår i: American Journal of Hypertension. - : Oxford University Press (OUP). - 0895-7061 .- 1941-7225. ; 26:4, s. 567-573
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND Fibro-calcification of the mitral annulus (MAC) has been associated with increased risk of ischemic stroke in general populations. This study was performed to assess whether MAC predicts incidence of ischemic stroke in treated hypertensive patients with left ventricular hypertrophy (LVH).METHODS Baseline and follow-up clinical and echocardiographic parameters were assessed in 939 hypertensive patients with electrocardiogram (ECG) LVH participating in the Losartan Intervention for Endpoint reduction in hypertension (LIFE) echocardiography substudy (66 +/- 7 years; 42% women; 11% with diabetes) who did not have aortic or mitral valve stenosis or prosthesis.RESULTS MAC was found in 458 patients (49%). Patients with MAC were older (68 +/- 7 vs. 65 +/- 7 years); were more often women (47% vs. 37%); had higher baseline systolic blood pressure (BP) (175 +/- 14 vs. 172 +/- 15 mm Hg), left atrial diameter (4.0 +/- 0.5 vs. 3.8 +/- 0.6 cm), and left ventricular mass index (58 +/- 13 vs. 55 +/- 12 g/m(2.7)) and included more patients with proteinuria (30% vs. 21%; all P < 0.01). During a mean follow-up of 4.8 years, 58 participants had an ischemic stroke. Risk of incident ischemic stroke was significantly related to presence of MAC (log rank = 9; P < 0.01). In multivariable Cox regression analysis models, MAC was associated with increased risk of ischemic stroke (hazard ratio = 1.78-2.35), independent of age, baseline or time-varying systolic BR prevalence or incidence of atrial fibrillation, history of previous cerebrovascular disease, and other well-recognized confounders, such as sex, time-varying left ventricular mass, left atrial diameter, and urinary albumin/creatinine ratio (all P < 0.05).CONCLUSIONS MAC is common in treated hypertensive patients with ECG LVH and is an independent predictor of incident ischemic stroke.
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| 5. |
- Bang, Casper N., et al.
(författare)
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Four-Group Classification of Left Ventricular Hypertrophy Based on Ventricular Concentricity and Dilatation Identifies a Low-Risk Subset of Eccentric Hypertrophy in Hypertensive Patients
- 2014
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Ingår i: Circulation Cardiovascular Imaging. - 1941-9651 .- 1942-0080. ; 7:3, s. 422-429
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Tidskriftsartikel (refereegranskat)abstract
- Background-Left ventricular hypertrophy (LVH; high LV mass [LVM]) is traditionally classified as concentric or eccentric based on LV relative wall thickness. We evaluated the prediction of subsequent adverse events in a new 4-group LVH classification based on LV dilatation (high LV end-diastolic volume [EDV] index) and concentricity (mass/end-diastolic volume [M/EDV](2/3)) in hypertensive patients. Methods and Results-In the Losartan Intervention for Endpoint Reduction (LIFE) echocardiography substudy, 939 hypertensive patients with measurable LVM at baseline were randomized to a mean of 4.8 years of losartan- or atenolol-based treatment. Patients with LVH (LVM/body surface area >= 116 and >= 96 g/m(2) in men and woman, respectively) were divided into 4 groups-concentric nondilated (increased M/EDV, normal EDV), eccentric dilated (increased EDV, normal M/EDV), concentric dilated (increased M/EDV and EDV), and eccentric nondilated (normal M/EDV and EDV)-and compared with patients with normal LVM. Time-varying LVH classes were tested for association with all-cause and cardiovascular mortality and a composite end point of myocardial infarction, stroke, heart failure, and cardiovascular death in multivariable Cox analyses. At baseline, the LVs were categorized as eccentric nondilated in 12%, eccentric dilated in 20%, concentric nondilated in 29%, concentric dilated in 14%, and normal LVM in 25%. Treatment changed the prevalence of 4 LVH groups to 23%, 4%, 5%, and 7%; 62% had normal LVM after 4 years. In time-varying Cox analyses, compared with normal LVM, those with eccentric dilated and both concentric nondilated and dilated LVH had increased risks of all-cause or cardiovascular mortality or the composite end point, whereas the eccentric nondilated group did not. Conclusions-Hypertensive patients with relatively mild LVH without either increased LV volume or concentricity have similar risk of all-cause mortality or cardiovascular events because hypertensive patients with normal LVM seem to be a low-risk group.
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| 6. |
- Mancusi, Costantino, et al.
(författare)
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Impact of isolated systolic hypertension on normalization of left ventricular structure during antihypertensive treatment (the LIFE study)
- 2014
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Ingår i: Blood Pressure. - : Informa UK Limited. - 0803-7051 .- 1651-1999. ; 23:4, s. 206-212
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: We tested the impact of isolated systolic hypertension (ISH) on normalization of left ventricular (LV) structure during antihypertensive treatment.METHODS: Baseline and annual echocardiograms were recorded in 873 hypertensive patients with electrocardiographic signs of LV hypertrophy during 4.8 years randomized losartan- or atenolol-based antihypertensive treatment in the Losartan Intervention For Endpoint (LIFE) reduction in hypertension study and classified as having ISH (n = 128) if systolic BP ≥ 160 mmHg and diastolic BP < 90 mmHg, or non-ISH divided into two groups by systolic BP ≥ 160 mmHg (non-ISH ≥ 160 mmHg) (n = 645) and systolic BP < 160 mm Hg (n = 100) (non-ISH < 160 mmHg), respectively.RESULTS: Patients with ISH were older, with higher prevalence of diabetes than non-ISH groups and higher pulse pressure/stroke volume index (all p < 0.05). Baseline systolic blood pressure (BP) differed between groups and was highest in the non-ISH ≥ 160 mmHg group (p < 0.05). Systolic BP reduction was less in the ISH group (p < 0.05). LV geometry did not differ between ISH and non-ISH ≥ 160 mmHg groups at baseline, but ISH had more residual LV hypertrophy of concentric type at the last study visit (p < 0.05). In multivariate analysis, less reduction of LV mass was predicted by ISH (β = - 0.07) independent of significant associations with baseline LVMi (β = 0.52) and atenolol-based treatment (β = - 0.08) and clinical confounders (all p < 0.05).CONCLUSIONS: ISH is associated with impaired normalization of LV mass during systematic antihypertensive treatment. The findings may help explain the higher cardiovascular event rate previously reported in ISH patients.
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