| 1. |
- Flink, Axel, et al.
(författare)
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Microstructural characterization of the tool-chip interface enabled by focused ion beam and analytical electron microscopy
- 2009
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Ingår i: WEAR. - : Elsevier BV. - 0043-1648. ; 266:11-12, s. 1237-1240
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Tidskriftsartikel (refereegranskat)abstract
- A method based on focused ion beam milling and analytical electron microscopy to investigate the nature of the tool-chip interface is presented. It is employed to study tool-chip interfaces of the rake face of a (Ti0.83Si0.17)N coated PCBN insert after turning of case-hardened steel. Analytical electron microscopy shows the presence of a smeared adhered layer on the coating, which consists of steel elements from the work-piece, oxygen, and Si and N, most likely originating from the coating.
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| 2. |
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| 3. |
- Johansson, Karl-Axel, et al.
(författare)
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The quality assurance process for the ARTSCAN head and neck study - a practical interactive approach for QA in 3DCRT and IMRT.
- 2008
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Ingår i: Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 87:2, s. 290-9
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Tidskriftsartikel (refereegranskat)abstract
- AIM: This paper describes the quality assurance (QA) work performed in the Swedish multicenter ARTSCAN (Accelerated RadioTherapy of Squamous cell CArcinomas in the head and Neck) trial to guarantee high quality in a multicenter study which involved modern radiotherapy such as 3DCRT or IMRT. MATERIALS AND METHODS: The study was closed in June 2006 with 750 randomised patients. Radiation therapy-related data for every patient were sent by each participating centre to the QA office where all trial data were reviewed, analysed and stored. In case of any deviation from the protocol, an interactive process was started between the QA office and the local responsible clinician and/or physicist to increase the compliance to the protocol for future randomised patients. Meetings and workshops were held on a regular basis for discussions on various trial-related issues and for the QA office to report on updated results. RESULTS AND DISCUSSION: This review covers the 734 patients out of a total of 750 who had entered the study. Deviations early in the study were corrected so that the overall compliance to the protocol was very high. There were only negligible variations in doses and dose distributions to target volumes for each specific site and stage. The quality of the treatments was high. Furthermore, an extensive database of treatment parameters was accumulated for future dose-volume vs. endpoint evaluations. CONCLUSIONS: This comprehensive QA programme increased the probability to draw firm conclusions from our study and may serve as a concept for QA work in future radiotherapy trials where comparatively small effects are searched for in a heterogeneous tumour population.
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| 4. |
- Knutsson, Axel, et al.
(författare)
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Thermal decomposition products in arc evaporated TiAlN/TiN multilayers
- 2008
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 93:14, s. 143110-
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Tidskriftsartikel (refereegranskat)abstract
- Cubic metastable Ti0.34Al0.66 N/TiN multilayers were grown by reactive arc evaporation using Ti33-Al67 and Ti cathodes in a N2 atmosphere. X-ray diffractometry and high resolution transmission electron microscopy revealed that metastable c-Ti 0.34Al0.66N partly decomposes after annealing at 900 °C into c-TiN rich and c-AlN rich phases with retained lattice coherency. Elemental mapping by energy dispersive x-ray spectroscopy showed a homogenous distribution of Ti and Al in the as-deposited 25 nm Ti0.34Al 0.66N layers. The annealed Ti0.34Al0.66N layers exhibited coherent 5 nm domains with high Al content surrounded by a high Ti content matrix. This nanostructure formation is discussed in terms of spinodal decomposition. © 2008 American Institute of Physics.
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| 5. |
- Liuba, Petru, et al.
(författare)
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Protective effects of simvastatin on coronary artery function in swine with acute infection.
- 2006
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Ingår i: Atherosclerosis. - : Elsevier BV. - 1879-1484 .- 0021-9150. ; 186:2, s. 331-336
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Tidskriftsartikel (refereegranskat)abstract
- Background: The risk for coronary events may rise during acute infection. Perturbation in coronary endothelial function emerges as one important link. We investigated whether simvastatin could protect the coronary arterial function from the adverse effects of acute infection in swine. Methods: Coronary endothelium-dependent and -independent vasomotor responses were assessed by Doppler velocimetry in 12 Chlamydia pneunioniae-infected and 6 sham-infected swine 2 weeks after intratracheal inoculation. Half of animals from the infection group were pretreated with simvastatin (80 mg daily), while the remaining animals received placebo. The treatment was started 2 weeks prior to inoculation and Continued until the end of the Study. ANOVA was used for statistical calculations. Data are mean +/- S.D. Results: All animals inoculated with C. pneumoniae developed IgM antibodies against this organism. As compared to noninfected animals, peak-to-baseline coronary flow velocity (CFV) ratio after bradykinin was significantly decreased in infected animals regardless of statin treatment (1,p=0.01). Intracoronary 10(-6) M acetylcholine caused slight dilatory responses in both noninfected and infected-treated animals (CFV ratio: 1.6 +/- 0.2and 1.4 +/- 0.2, respectively: p > 0.1),while a velocity drop (CFV ratio: 0.7 +/- 0.1; p < 0.01 versus noninfected-infected and treated). indicating constriction, was observed in in fected-non treated animals; 10(-5) M acetylcholine caused vasoconstriction in all animals, with a significantly more prolonged response in the infected-non treated group (p < 0.01). Intracoronary adenosine and SNP induced similar dilatory responses in all groups (p > 0.5). There were no differences in markers of systemic inflammation (fibrinogen, amyloid, and CRP) and lipid profile (HDL, LDL and total cholesterol) between the groups (p > 0.2). Conclusion: Acute infection is associated with impairment of the muscarinic and kinin-related reactivity of coronary circulation. These functional abnormalities are in part prevented by simvastatin through mechanisms unrelated to lipid lowering. (c) 2005 Elsevier Ireland Ltd. All rights reserved.
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| 6. |
- Persson, Daniel, 1978, et al.
(författare)
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Finite and infinite-dimensional symmetries of pure N=2 supergravity in D=4
- 2009
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Ingår i: Journal of High Energy Physics. - : Springer Science and Business Media LLC. - 1029-8479 .- 1126-6708.
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Tidskriftsartikel (refereegranskat)abstract
- We study the symmetries of pure N=2 supergravity in D=4. As is known, this theory reduced on one Killing vector is characterised by a non-linearly realised symmetry SU(2,1) which is a non-split real form of SL(3,C). We consider the BPS brane solutions of the theory preserving half of the supersymmetry and the action of SU(2,1) on them. Furthermore we provide evidence that the theory exhibits an underlying algebraic structure described by the Lorentzian Kac-Moody group SU(2,1)^{+++}. This evidence arises both from the correspondence between the bosonic space-time fields of N=2 supergravity in D=4 and a one-parameter sigma-model based on the hyperbolic group SU(2,1)^{++}, as well as from the fact that the structure of BPS brane solutions is neatly encoded in SU(2,1)^{+++}. As a nice by-product of our analysis, we obtain a regular embedding of the Kac-Moody algebra su(2,1)^{+++} in e_{11} based on brane physics.
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| 7. |
- Persson, Daniel, 1978, et al.
(författare)
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Instanton Corrections to the Universal Hypermultiplet and Automorphic Forms on SU(2,1)
- 2009
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Ingår i: Preprint: arXiv:0909.4299 [hep-th]. ; , s. 55 pages-
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The hypermultiplet moduli space in Type IIA string theory compactified on a rigid Calabi-Yau threefold X, corresponding to the "universal hypermultiplet", is described at tree-level by the symmetric space SU(2,1)/(SU(2) x U(1)). To determine the quantum corrections to this metric, we posit that a discrete subgroup of the continuous tree-level isometry group SU(2,1), namely the Picard modular group SU(2,1;Z[i]), must remain unbroken in the exact metric -- including all perturbative and non perturbative quantum corrections. This assumption is expected to be valid when X admits complex multiplication by Z[i]. Based on this hypothesis, we construct an SU(2,1;Z[i])-invariant, non-holomorphic Eisenstein series, and tentatively propose that this Eisenstein series provides the exact contact potential on the twistor space over the universal hypermultiplet moduli space. We analyze its non-Abelian Fourier expansion, and show that the Abelian and non-Abelian Fourier coefficients take the required form for instanton corrections due to Euclidean D2-branes wrapping special Lagrangian submanifolds, and to Euclidean NS5-branes wrapping the entire Calabi-Yau threefold, respectively. While this tentative proposal fails to reproduce the correct one-loop correction, the consistency of the Fourier expansion with physics expectations provides strong support for the utility of the Picard modular group in constraining the quantum moduli space.
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| 8. |
- Persson, Daniel, 1978, et al.
(författare)
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Massive Type IIA Supergravity and E10
- 2009
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Ingår i: Fortschritte der Physik. - : Wiley. - 0015-8208 .- 1521-3978. ; 57:5-7, s. 580-586
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Tidskriftsartikel (refereegranskat)abstract
- In this talk we investigate the symmetry under E10 of Romans' massive type IIA supergravity. We show that the dynamics of a spinning particle in a non-linear sigma model on the coset space E10/K(E10) reproduces the bosonic and fermionic dynamics of massive IIA supergravity, in the standard truncation. In particular, we identify Romans' mass with a generator of E10 that is beyond the realm of the generators of E10 considered in the eleven-dimensional analysis, but using the same, underformed sigma model. As a consequence, this work provides a dynamical unification of the massless and massive versions of type IIA supergravity inside E10.
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| 9. |
- Persson, Daniel, 1978, et al.
(författare)
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On the E10/Massive Type IIA Supergravity Correspondence
- 2009
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Ingår i: Physical Review D - Particles, Fields, Gravitation and Cosmology. - 2470-0010 .- 2470-0029. ; 79:4, s. 045088-
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Tidskriftsartikel (refereegranskat)abstract
- In this paper we investigate in detail the correspondence between E10 and Romans' massive deformation of type IIA supergravity. We analyse the dynamics of a non-linear sigma model for a spinning particle on the coset space E10/K(E10) and show that it reproduces the dynamics of the bosonic as well as the fermionic sector of the massive IIA theory, within the standard truncation. The mass deformation parameter corresponds to a generator of E10 outside the realm of the generators entering the usual D=11 analysis, and is naturally included without any deformation of the coset model for E10/K(E10). Our analysis thus provides a dynamical unification of the massless and massive versions of type IIA supergravity inside E10. We discuss a number of additional and general features of relevance in the analysis of any deformed supergravity in the correspondence to Kac-Moody algebras, including recently studied deformations where the trombone symmetry is gauged.
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| 10. |
- Persson, Gunnar E., et al.
(författare)
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Surgical treatment of gallstones : changes in a defined population during a 20-year period
- 2002
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Ingår i: European Journal of Surgery. - : Oxford University Press (OUP). - 1102-4151 .- 1741-9271. ; 168:1, s. 13-17
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Tidskriftsartikel (refereegranskat)abstract
- Objective:To study developments in routine gallstone surgery in a defined population over a 20-year period with regard to incidence of operations, implementation of new methods, postoperative complications, and postoperative duration of hospital stay.Design:Retrospective study of medical records.Setting:County hospital, Sweden.Subjects:All patients who were residents of Jönköping during one of the three-year periods 1976–1978, 1986–1988, or 1996–1998 and had their first surgical treatment, either cholecystectomy/choledochotomy or therapeutic endoscopy for gallstone disease.Results:The overall annual incidence of operations for gallstones decreased from 2.01 to 1.13/1000 inhabitants between the first and second period (p < 0.001). This is explained by a significant reduction in the number of elective operations while the number of urgent operations increased between the first and second periods from 0.39 to 0.53/1000 (p < 0.05) and continued to increase and reached 0.75/1000 during the third period (p < 0.001). New methods were introduced for the treatment of gallstones that gradually made this type of operation more varied and complex in routine practice. The postoperative hospital stay decreased from 7.0 days during the 1970s to 3.9 days during the 1990s. Postoperative morbidity was unchanged.Conclusions:The decreasing rate of gallstone surgery noted between the 1970s and 1980s did not continue through the 1990s. Urgent surgery for gallstone disease has gradually become more common and now predominates over elective surgery in routine practice. The introduction of less traumatic surgical techniques contributed to the significant decrease in hospital stay after gallstone surgery. However, morbidity has not decreased and the diversification of surgical techniques used for treatment of gallstones requires continuous evaluation in routine practice.
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