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- Schael, S, et al.
(författare)
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Precision electroweak measurements on the Z resonance
- 2006
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Ingår i: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 427:5-6, s. 257-454
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Forskningsöversikt (refereegranskat)abstract
- We report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electron-positron colliders SLC and LEP. The data consist of 17 million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLID experiment using a polarised beam at SLC. The measurements include cross-sections, forward-backward asymmetries and polarised asymmetries. The mass and width of the Z boson, m(Z) and Gamma(Z), and its couplings to fermions, for example the p parameter and the effective electroweak mixing angle for leptons, are precisely measured: m(Z) = 91.1875 +/- 0.0021 GeV, Gamma(Z) = 2.4952 +/- 0.0023 GeV, rho(l) = 1.0050 +/- 0.0010, sin(2)theta(eff)(lept) = 0.23153 +/- 0.00016. The number of light neutrino species is determined to be 2.9840 +/- 0.0082, in agreement with the three observed generations of fundamental fermions. The results are compared to the predictions of the Standard Model (SM). At the Z-pole, electroweak radiative corrections beyond the running of the QED and QCD coupling constants are observed with a significance of five standard deviations, and in agreement with the Standard Model. Of the many Z-pole measurements, the forward-backward asymmetry in b-quark production shows the largest difference with respect to its SM expectation, at the level of 2.8 standard deviations. Through radiative corrections evaluated in the framework of the Standard Model, the Z-pole data are also used to predict the mass of the top quark, m(t) = 173(+10)(+13) GeV, and the mass of the W boson, m(W) = 80.363 +/- 0.032 GeV. These indirect constraints are compared to the direct measurements, providing a stringent test of the SM. Using in addition the direct measurements of m(t) and m(W), the mass of the as yet unobserved SM Higgs boson is predicted with a relative uncertainty of about 50% and found to be less than 285 GeV at 95% confidence level. (c) 2006 Elsevier B.V. All rights reserved.
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| 3. |
- Mathieu, Roland, et al.
(författare)
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Coexistence of long-ranged charge and orbital order and spin-glass state in single-layered manganites with weak quenched disorder
- 2007
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Ingår i: Europhysics letters. - : IOP Publishing. - 0295-5075 .- 1286-4854. ; 80:3, s. 37001-
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Tidskriftsartikel (refereegranskat)abstract
- The relationship between orbital and spin degrees of freedom in the single crystals of the hole-doped Pr1-xCa1+xMnO4, 0.3 <= x <= 0.7 has been investigated by means of ac-magnetometry and charge transport. We show that in an intermediate underdoped region, with 0.35 <= x < 0.5, the "orbital-master spin-slave" relationship commonly observed in half-doped manganites does not take place. The long-ranged charge-orbital order is not accompanied by an antiferromagnetic transition at low temperatures, but by a frustrated short-ranged magnetic state bringing forth a spin-glass phase. We discuss in detail the nature and origin of this true spin-glass state, which, as in the half-doped manganites with large quenched disorder, is not related to the macroscopic phase separation observed in crystals with minor defects or impurities.
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| 4. |
- Norberg, Åke, et al.
(författare)
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Volume turnover kinetics of fluid shifts after hemorrhage, fluid infusion, and the combination of hemorrhage and fluid infusion in sheep
- 2005
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Ingår i: Anesthesiology. - : Lippincott Williams & Wilkins. - 0003-3022 .- 1528-1175. ; 102:5, s. 985-994
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Hemorrhage is commonly treated with intravenous infusion of crystalloids. However, the dynamics of fluid shifts between body fluid spaces are not completely known, causing contradictory recommendations regarding timing and volume of fluid infusions. The authors have developed a turnover model that characterizes these fluid shifts.METHODS: Conscious, chronically instrumented sheep (n = 12) were randomly assigned to three protocol groups: infusion of 25 ml/kg of 0.9% saline over 20 min (infusion only), hemorrhage of 300 ml (7.8 +/- 1.1 ml/kg) over 5 min (hemorrhage only), and hemorrhage of 300 ml over 5 min followed by infusion as noted above (hemorrhage plus infusion). A two-compartment volume turnover kinetic model containing seven model parameters was fitted to data obtained by repeated sampling of hemoglobin concentration and urinary excretion.RESULTS: The volume turnover model successfully predicted fluid shifts. Mean baseline volumes of the central and tissue compartments were 1799 +/- 1276 ml and 7653 +/- 5478 ml, respectively. Immediate fluid infusion failed to prevent hemorrhage-induced depression of cardiac output and diuresis. The model suggested that volume recruitment to the central compartment after hemorrhage was primarily achieved by mechanisms other than volume equilibration between the two model compartments.CONCLUSION: Volume turnover kinetics is a promising tool for explaining fluid shifts between body compartments after perturbations such as hemorrhage and intravenous fluid infusions. The pronounced inhibition of renal output after hemorrhage prevailed regardless of fluid infusion and caused fluid retention, which expanded the tissue compartment.
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| 5. |
- Vincenti, F., et al.
(författare)
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Results of an international, randomized trial comparing glucose metabolism disorders and outcome with cyclosporine versus tacrolimus
- 2007
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Ingår i: American journal of transplantation. - : Elsevier BV. - 1600-6135. ; 7:6, s. 1506-14
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Tidskriftsartikel (refereegranskat)abstract
- DIRECT (Diabetes Incidence after Renal Transplantation: Neoral C(2) Monitoring Versus Tacrolimus) was a 6-month, open-label, randomized, multicenter study which used American Diabetes Association/World Health Organization criteria to define glucose abnormalities. De novo renal transplant patients were randomized to cyclosporine microemulsion (CsA-ME, using C(2) monitoring) or tacrolimus, with mycophenolic acid, steroids and basiliximab. The intent-to-treat population comprised 682 patients (336 CsA-ME, 346 tacrolimus): 567 were nondiabetic at baseline. Demographics, diabetes risk factors and steroid doses were similar between treatment groups. The primary safety endpoint, new-onset diabetes after transplant (NODAT) or impaired fasting glucose (IFG) at 6 months, occurred in 73 CsA-ME patients (26.0%) and 96 tacrolimus patients (33.6%, p = 0.046). The primary efficacy endpoint, biopsy-proven acute rejection, graft loss or death at 6 months, occurred in 43 CsA-ME patients (12.8%) and 34 tacrolimus patients (9.8%, p = 0.211). Mean glomerular filtration rate (Cockcroft-Gault) was 63.6 +/- 20.7 mL/min/1.73 m(2) in the CsA-ME cohort and 65.9 +/- 23.1 mL/min/1.73 m(2) with tacrolimus (p = 0.285); mean serum creatinine was 139 +/- 58 and 133 +/- 57 mumol/L, respectively (p = 0.005). Blood pressure was similar between treatment groups at month 6, but total cholesterol, LDL-cholesterol and triglyceride levels were significantly higher with CsA than with tacrolimus (total cholesterol:HDL remained unchanged). The profile and incidence of adverse events were similar between treatments. The incidence of NODAT or IFG at 6 months post-transplant is significantly lower with CsA-ME than with tacrolimus without a significant difference in short-term outcome.
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