| 1. |
- Schael, S., et al.
(författare)
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Electroweak measurements in electron positron collisions at W-boson-pair energies at LEP
- 2013
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Ingår i: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 532:4, s. 119-244
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Forskningsöversikt (refereegranskat)abstract
- Electroweak measurements performed with data taken at the electron positron collider LEP at CERN from 1995 to 2000 are reported. The combined data set considered in this report corresponds to a total luminosity of about 3 fb(-1) collected by the four LEP experiments ALEPH, DELPHI, 13 and OPAL, at centre-of-mass energies ranging from 130 GeV to 209 GeV. Combining the published results of the four LEP experiments, the measurements include total and differential cross-sections in photon-pair, fermion-pair and four-fermion production, the latter resulting from both double-resonant WW and ZZ production as well as singly resonant production. Total and differential cross-sections are measured precisely, providing a stringent test of the Standard Model at centre-of-mass energies never explored before in electron positron collisions. Final-state interaction effects in four-fermion production, such as those arising from colour reconnection and Bose Einstein correlations between the two W decay systems arising in WW production, are searched for and upper limits on the strength of possible effects are obtained. The data are used to determine fundamental properties of the W boson and the electroweak theory. Among others, the mass and width of the W boson, m(w) and Gamma(w), the branching fraction of W decays to hadrons, B(W -> had), and the trilinear gauge-boson self-couplings g(1)(Z), K-gamma and lambda(gamma), are determined to be: m(w) = 80.376 +/- 0.033 GeV Gamma(w) = 2.195 +/- 0.083 GeV B(W -> had) = 67.41 +/- 0.27% g(1)(Z) = 0.984(-0.020)(+0.018) K-gamma - 0.982 +/- 0.042 lambda(gamma) = 0.022 +/- 0.019. (C) 2013 Elsevier B.V. All rights reserved.
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| 2. |
- 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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| 7. |
- Fischer, F., et al.
(författare)
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Expansion of nickel binding- and histidine-rich proteins during gastric adaptation of Helicobacter species
- 2022
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Ingår i: Metallomics. - : Oxford University Press (OUP). - 1756-5901 .- 1756-591X. ; 14:9
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Tidskriftsartikel (refereegranskat)abstract
- Acquisition and homeostasis of essential metals during host colonization by bacterial pathogens rely on metal uptake, trafficking, and storage proteins. How these factors have evolved within bacterial pathogens is poorly defined. Urease, a nickel enzyme, is essential for Helicobacter pylori to colonize the acidic stomach. Our previous data suggest that acquisition of nickel transporters and a histidine-rich protein (HRP) involved in nickel storage in H. pylori and gastric Helicobacter spp. have been essential evolutionary events for gastric colonization. Using bioinformatics, proteomics, and phylogenetics, we extended this analysis to determine how evolution has framed the repertoire of HRPs among 39 Epsilonproteobacteria; 18 gastric and 11 non-gastric enterohepatic (EH) Helicobacter spp., as well as 10 other Epsilonproteobacteria. We identified a total of 213 HRPs distributed in 22 protein families named orthologous groups (OGs) with His-rich domains, including 15 newly described OGs. Gastric Helicobacter spp. are enriched in HRPs (7.7 +/- 1.9 HRPs/strain) as compared to EH Helicobacter spp. (1.9 +/- 1.0 HRPs/strain) with a particular prevalence of HRPs with C-terminal histidine-rich domains in gastric species. The expression and nickel-binding capacity of several HRPs was validated in five gastric Helicobacter spp. We established the evolutionary history of new HRP families, such as the periplasmic HP0721-like proteins and the HugZ-type heme oxygenases. The expansion of histidine-rich extensions in gastric Helicobacter spp. proteins is intriguing but can tentatively be associated with the presence of the urease nickel enzyme. We conclude that this HRP expansion is associated with unique properties of organisms that rely on large intracellular nickel amounts for their survival.
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| 8. |
- Hallström, Inger, et al.
(författare)
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Pain and nutrition as experienced by patients with hip fracture
- 2000
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Ingår i: Journal of Clinical Nursing. - : Wiley. - 1365-2702 .- 0962-1067. ; 9:4, s. 639-646
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this study was to investigate patients' experiences of care in connection with hip fracture. The care process was examined through non-participant observation, informal field interviews and healthcare records. The findings showed that many factors in the healthcare services directly or indirectly influence patients' perceptions of the quality of care. Some of these factors may depend upon a varying knowledge and empathy, while others are due to a lack of agreed protocols/procedures. Patients' needs with respect to pain relief and nutrition are discussed.
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| 9. |
- Idvall, Ewa, et al.
(författare)
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A tentative model for developing strategic and clinical nursing quality indicators : postoperative pain management
- 1999
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Ingår i: International journal of nursing practice. - 1322-7114. ; 5:4, s. 216-226
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of the study was to evaluate the usefulness of a tentative model, based on important aspects of surgical nursing care, for designing strategic and clinical quality indicators. Objective postoperative pain management was chosen for the model because it is a priority area in surgical nursing care. Items within a questionnaire were designed by using the tentative model as a base and by means of a literature review. The questionnaire, directed to clinical nurses (n = 233), was compiled to establish the validity and the usefulness of the indicators. Fourteen items were assessed as essential for achieving high quality outcomes in postoperative pain management (11 as realistic to carry out, and 13 as possible for nurses to influence) with mean scores > or = 4 (on a 5-point scale). The conclusion reached was that the tentative model combined with a literature search was found to be effective for designing items that might be useful as strategic and clinical indicators of quality in postoperative pain management.
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| 10. |
- Idvall, Ewa, et al.
(författare)
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Important aspects of nursing care in surgical wards as expressed by nurses
- 1998
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Ingår i: Journal of Clinical Nursing. - 0962-1067. ; 7:6, s. 512-520
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to find out clinical nurses' perceptions of important aspects of nursing care that might have an impact on quality of care in surgical wards. A qualitative approach using focus group interviews was used. The data analysis revealed 15 categories of important aspects of care which could be condensed into two dimensions, here called 'prerequisites' (i.e., staffing, routines and attitudes) and 'elements of performance' (i.e., detecting and acting on signs and symptoms and acting on behalf of the patients). These aspects could be a starting point for developing quality indicators. Carper's four fundamental patterns of knowing were used to make a theoretical interpretation, and three of them were identified.
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