| 1. |
- 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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| 2. |
- 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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| 3. |
- Li, Jia, et al.
(författare)
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Oscillations of sub-membrane ATP in glucose-stimulated beta cells depend on negative feedback from Ca2
- 2013
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Ingår i: Diabetologia. - : Springer Science and Business Media LLC. - 0012-186X .- 1432-0428. ; 56:7, s. 1577-1586
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Tidskriftsartikel (refereegranskat)abstract
- ATP links changes in glucose metabolism to electrical activity, Ca2+ signalling and insulin secretion in pancreatic beta cells. There is evidence that beta cell metabolism oscillates, but little is known about ATP dynamics at the plasma membrane, where regulation of ion channels and exocytosis occur. The sub-plasma-membrane ATP concentration ([ATP](pm)) was recorded in beta cells in intact mouse and human islets using total internal reflection microscopy and the fluorescent reporter Perceval. Glucose dose-dependently increased [ATP](pm) with half-maximal and maximal effects at 5.2 and 9 mmol/l, respectively. Additional elevations of glucose to 11 to 20 mmol/l promoted pronounced [ATP](pm) oscillations that were synchronised between neighbouring beta cells. [ATP](pm) increased further and the oscillations disappeared when voltage-dependent Ca2+ influx was prevented. In contrast, K+-depolarisation induced prompt lowering of [ATP](pm). Simultaneous recordings of [ATP](pm) and the sub-plasma-membrane Ca2+ concentration ([Ca2+](pm)) during the early glucose-induced response revealed that the initial [ATP](pm) elevation preceded, and was temporarily interrupted by the rise of [Ca2+](pm). During subsequent glucose-induced oscillations, the increases of [Ca2+](pm) correlated with lowering of [ATP](pm). In beta cells, glucose promotes pronounced oscillations of [ATP](pm), which depend on negative feedback from Ca2+ (.) The bidirectional interplay between these messengers in the sub-membrane space generates the metabolic and ionic oscillations that underlie pulsatile insulin secretion.
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| 4. |
- Wang, Zanxin, et al.
(författare)
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Confined ischemia may improve remote myocardial outcome after rat cardiac arrest
- 2014
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Ingår i: Scandinavian Journal of Clinical and Laboratory Investigation. - : Informa UK Limited. - 0036-5513 .- 1502-7686. ; 74:1, s. 27-36
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundConfined ongoing ischemia after ischemia-reperfusion injury (IRI) may alter myocardial recovery. We evaluated in a rat cardiac transplantation model whether distal persistent myocardial ischemia (dMI) and remote preconditioning (RPreC) have a remote myocardial impact after IRI.Material and methodsSyngeneic heterotopic cardiac transplantation was performed on 29 Fischer344 rats to induce IRI, including nine rats which underwent distal ligation of the left anterior coronary artery (LAD) to yield distal MI (IRI+ dMI). RPreC was applied by occluding the left renal artery 5 min prior to reperfusion in six rats with IRI (IRI+ RPreC) as well as in seven with distal MI (IRI+ dMI+ RPreC). Microdialysis, histology and qRT-PCR for inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) were performed after graft harvesting.ResultsIn contrast to IRI + dMI + RPreC (39 ± 7 μmol), glutamate decreased in IRI + RPreC and IRI + dMI as compared with IRI (26 ± 3 and 31 ± 8 vs 91 ± 20, μmol respectively, p < 0.007). The relative number of vacuolated intramyocardial artery nuclei decreased in IRI + dMI as compared with IRI (0.02 ± 0.01, range 0-12 vs. 0.42 ± 0.31, range 0-3.25 PSU respectively, p < 0.04). iNOS expression decreased in IRI + RPreC as compared with IRI (p < 0.04), and eNOS expression decreased in IRI + dMI + RPreC as compared with IRI + dMI (p < 0.006) along with increased glycerol release.ConclusionsdMI after IRI has a potentially beneficial myocardial impact after cardiac arrest, which is hampered by RPreC.
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