| 21. |
- Ahuja, Rajeev, et al.
(författare)
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Optical properties of 4H-SiC
- 2002
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 91:4, s. 2099-2103
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Tidskriftsartikel (refereegranskat)abstract
- The optical band gap energy and the dielectric functions of n-type 4H-SiC have been investigated experimentally by transmission spectroscopy and spectroscopic ellipsometry and theoretically by an ab initio full-potential linear muffin-tin-orbital method. We present the real and imaginary parts of the dielectric functions, resolved into the transverse and longitudinal photon moment a, and we show that the anisotropy is small in 4H-SiC. The measurements and the calculations fall closely together in a wide range of energies.
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| 22. |
- Andersson, Bodil, et al.
(författare)
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Combining Keystroke Logging with Eye Tracking
- 2006
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Ingår i: Writing and Digital Media. - 1572-6304. - 0080448631 ; 17, s. 166-172
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Bokkapitel (refereegranskat)abstract
- This chapter describes the successful development of a new methodology for studying on-line writing. The text-logging tool ScriptLog has been combined with the eyetracking technology iView X HED HT, in order to enhance the study of the interplay between writing, monitoring and revision. Data on the distribution of visual attention during writing help determining to what extent pauses are used for monitoring. The complexity of the experimental settings, and the expertise needed for interpreting the eye-tracking data make this a method suitable mainly for laboratory settings. The chapter also introduces an analysis tool that merges data from ScriptLog and iView and thus helps the researcher to organise and analyse the vast amount of data produced.
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| 23. |
- Andersson, Irene, 1978, et al.
(författare)
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Endothelial dysfunction in growth hormone transgenic mice
- 2006
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Ingår i: Clinical Science. - 0143-5221 .- 1470-8736. ; 110:2, s. 217-25
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Tidskriftsartikel (refereegranskat)abstract
- Acromegaly [overproduction of GH (growth hormone)] is associated with cardiovascular disease. Transgenic mice overexpressing bGH (bovine GH) develop hypertension and hypercholesterolaemia and could be a model for cardiovascular disease in acromegaly. The aims of the present study were to investigate the effects of excess GH on vascular function and to test whether oxidative stress affects endothelial function in bGH transgenic mice. We studied the ACh (acetylcholine)-induced relaxation response in aortic and carotid rings of young (9-11 weeks) and aged (22-24 weeks) female bGH transgenic mice and littermate control mice, without and with the addition of a free radical scavenger {MnTBAP [Mn(III)tetrakis(4-benzoic acid)porphyrin chloride]}. We also measured mRNA levels of eNOS (endothelial nitric oxide synthase) and EC-SOD (extracellular superoxide dismutase). Intracellular superoxide anion production in the vascular wall was estimated using a dihydroethidium probe. Carotid arteries from bGH transgenic mice had an impaired ACh-induced relaxation response (young, 46 +/- 7% compared with 69 +/- 8%; aged, 52 +/- 5% compared with 80 +/- 3%; P < 0.05), whereas endothelial function in aorta was intact in young but impaired in aged bGH transgenic mice. Endothelial dysfunction was corrected by addition of MnTBAP in carotid arteries from young mice and in aortas from aged mice; however, MnTBAP did not correct endothelial dysfunction in carotid arteries from aged bGH transgenic mice. There was no difference in intracellular superoxide anion production between bGH transgenic mice and control mice, whereas mRNA expression of EC-SOD and eNOS was increased in aortas from young bGH transgenic mice compared with control mice (P < 0.05). We interpret these data to suggest that bGH overexpression is associated with a time- and vessel-specific deterioration in endothelial function, initially caused by increased oxidative stress and later by other alterations in vascular function.
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| 24. |
- Andersson, Kenneth, 1970-, et al.
(författare)
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Backward-forward motion compensated prediction
- 2002
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Ingår i: Proceedings of ACIVS 2002 (Advanced Concepts for Intelligent Vision Systems), Ghent, Belgium, September 9-11, 2002. ; , s. 260-267
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Konferensbidrag (refereegranskat)abstract
- This paper presents new methods for use of dense motion fields for motion compensation of interlaced video. The motion is estimated using previously decoded field-images. An initial motion compensated prediction is produced using the assumption that the motion is predictable in time. The motion estimation algorithm is phase-based and uses two or three field-images to achieve motion estimates with sub-pixel accuracy. To handle non-constant motion and the specific characteristics of the field-image to be coded, the initially predicted image is refined using forward motion compensation, based on block-matching. Tests show that this approach achieves higher PSNR than forward block-based motion estimation, when coding the residual with the same coder. The subjective performance is also better.
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| 25. |
- Andersson, Kenneth, 1970-, et al.
(författare)
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Motion compensation using backward prediction and prediction refinement
- 2003
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Ingår i: Signal Processing: Image Communication. - 0923-5965. ; 18:5, s. 381-400
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents new methods for use of dense motion fields for motion compensation of interlaced video. The motion estimation is based on previously decoded field-images. The motion is then temporally predicted and used for motion compensated prediction of the field-image to be coded. The motion estimation algorithm is phase-based and uses two or three field-images to achieve motion estimates with sub-pixel accuracy. To handle non-constant motion and the specific characteristics of the field-image to be coded, the initially predicted image is refined using forward motion compensation, based on block-matching. Tests show that this approach achieves higher PSNR than forward block-based motion estimation, when coding the residual with the same coder. The subjective performance is also better.
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| 26. |
- Billy, J., et al.
(författare)
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Stress-relief heat treatment of submerged-arc-welded microalloyed steels
- 1980
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Ingår i: Metals Technology. - : Informa UK Limited. - 0307-1693. ; 7:2, s. 67-78
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Tidskriftsartikel (refereegranskat)abstract
- A wide range of microalloyed steels containing various combinations of Al, Ti, V, Nb, and submerged-arc welded using wires of either high or low Mo additions, were studied in both the as-welded and stress-relieved conditions, with particular reference to impact toughness and microstructure. It was found that, irrespective of thermal treatment, the heat-affected base metal always has a much lower impact transition temperature than the weld metal. In the as-welded condition, the most important constituent with respect to toughness is the amount of pro-eutectoid ferrite present
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| 27. |
- Bohman, Anton, et al.
(författare)
-
Heredity of nasal polyps.
- 2015
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Ingår i: Rhinology. - 0300-0729. ; 53:1, s. 25-8
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Tidskriftsartikel (refereegranskat)abstract
- Nasal polyps is a common disease but little is known about its` pathogenesis. Our hypothesis was that there are genetic factors involved in the development of this disease. The aim of this study was to examine close relatives of patients with nasal polyps and comparing them with a general population with regard to prevalence of polyps.
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| 28. |
- Bohman, Anton, et al.
(författare)
-
Heredity of nasal polyps
- 2015
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Ingår i: Rhinology. - 0300-0729 .- 1996-8604. ; 53:1, s. 25-28
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Tidskriftsartikel (refereegranskat)abstract
- Background: Nasal polyps is a common disease but little is known about its' pathogenesis. Our hypothesis was that there are genetic factors involved in the development of this disease. The aim of this study was to examine close relatives of patients with nasal polyps and comparing them with a general population with regard to prevalence of polyps. Methodology: Patients with nasal polyps who attended the clinic were recruited to the study and were asked whether they had any close adult relatives (siblings, parents or children). We intended to recruit two relatives per patient, one of each gender, for nasal endoscopy. The prevalence of nasal polyps in these relatives was compared with the prevalence of nasal polyps in a general population. Results: During a 4-year period, 368 patients and 410 relatives were recruited to the study. Although we were unable to recruit two close relatives for every patient, we were able to calculate nasal polyp prevalence within families as being 19.2%. Compared with the prevalence of nasal polyps among individuals in a general Swedish population from the same geographical area, the relative risk for polyps among relatives was almost five times higher. Conclusion: This study strongly indicates that heredity is a factor of importance for development of nasal polyps.
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| 29. |
- Bohman, Anton, et al.
(författare)
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Relative frequencies of symptoms and risk factors among patients with chronic rhinosinusitis with nasal polyps using a case-control study
- 2018
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Ingår i: Acta Oto-Laryngologica. - : TAYLOR & FRANCIS LTD. - 0001-6489 .- 1651-2251. ; 138:1, s. 46-49
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: The aim of this study was to investigate the relative frequency of important symptoms of chronic rhinosinusitis with nasal polyps (CRSwNP), the link between CRSwNP and the lower airways and the importance of smoking in CRSwNP.Method: Three hundred and sixty-eight patients with CRSwNP and 1349 controls were recruited to the study and underwent a structured interview about symptoms from the upper and lower airways, and about smoking habits. Furthermore, all participants were clinically examined using nasal endoscopy.Results: Due to interactions between the outcome variables, a multiple logistic regression model was fitted to the data. Nasal secretions, nasal blockage and impaired sense of smell were symptoms associated with CRSwNP. Furthermore, male gender, increasing age and asthma were also associated with the disease. Current smoking was less frequent among patients with CRSwNP.Conclusion: By comparing symptoms and risk factors of patients with CRSwNP with those of a large population-based control group and testing them in a multiple logistic regression model, we have been able to generate data that address key research interests in CRSwNP.
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| 30. |
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