| 1. |
- af Klinteberg, C, et al.
(författare)
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Laser-induced fluorescence diagnostics of basal cell carcinomas of the skin following topical ALA application
- 1996
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Ingår i: Optical Biopsies and Microscopic Techniques, Proceedings of. - : SPIE. - 0819423289 ; 2926, s. 32-40
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Konferensbidrag (refereegranskat)abstract
- Fourteen patients with superficial basal cell carcinomas (BCCs) and fifteen patients with nodular BCCs were investigated by means of laser-induced fluorescence (LIF) in connection with photodynamic therapy (PDT). Topical application of delta-amino levulinic acid (ALA) was performed six hours prior to the treatment session. Fluorescence spectra were recorded, using a point-monitoring system with an excitation wavelength of 405 nm. The measurements were performed in scans over the lesion and the surrounding normal skin before application of ALA, and immediately before and after the laser treatment. The selective uptake of the photosensitiser resulted in a fluorescence intensity ratio of 2.4:1 for superficial BCCs and 2.5:1 for nodular BCCs. If the fluorescence intensity was divided by the autofluorescence, this resulted in a contrast enhancement of about a factor 6 for tumour tissue. In seven patients (five with nodular BCC and two with superficial BCC), additional fluorescence measurements were performed two and four hours following the ALA application, and two hours after the PDT procedure. Thus, the kinetics of the transformation of ACA to protoporphyrin IX (PpIX) could be followed, which indicated that the synthesis of PpIX was more rapid in the tumour than in the normal tissue. After four hours, the PpIX level inside the tumour was saturated, while there still was an accumulation in the surrounding skin. The highest contrast between tumour and normal skin was reached within two hours after the ALA application.
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| 2. |
- Axelsson, L., et al.
(författare)
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Study of the unbound nucleus 11N by elastic resonance scattering
- 1996
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813 .- 2469-9985 .- 2469-9993. ; 54:4, s. 1511-1514
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Tidskriftsartikel (refereegranskat)abstract
- Resonances in the unbound nucleus 11N have been studied, using the resonance scattering reaction 10C+p. The data give evidence for three states above the 10C+p threshold with energies 1.30, 2.04, and 3.72 MeV. These states can be interpreted, in a potential-model analysis, as the ground state and the first two excited states with spin-parity 1 / 2+, 1 / 2-, and 5 / 2+ arising from the shell-model orbitals 1s1 / 2, 0p1 / 2, and 0d5 / 2. A narrow state superposed on a broad structure found at higher energy could be interpreted as the mirror state of the 3 / 2- in 11Be shifted down in energy. This shift would suggest a large radius of the potential.
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| 6. |
- Nilsson, Annika, 1969, et al.
(författare)
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Optical properties of human whole blood - Changes due to slow heating
- 1996
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Ingår i: LASER-TISSUE INTERACTION AND TISSUE OPTICS II, PROCEEDINGS OF. - : SPIE. - 0819423254 ; 2923, s. 24-34
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Konferensbidrag (refereegranskat)abstract
- Optical properties of human whole blood were measured in vitro, at 633 nm with a double integrating sphere set-up, The blood was kept at constant flow through a flow cell while slowly heating the blood from approximately 25 degrees C to 55 degrees C in a heat exchanger, The results show a small but distinct decrease in the g-factor of 1.7 +/- 0.6\% and a similar increase in the scattering coefficient, mu(s), of 2.9 +/- 0.6\% at approximately 45-46 degrees C. When studying the thermal effect on the blood cells under a white-light transmission microscope, the changes in the scattering properties could be correlated to a sudden change in the shape of the red blood cells, from disc-shaped to spherical, at approximately the same temperature. Furthermore, a continuous manifest increase in the absorption coefficient, mu(a), was seen with temperature rise, on average 83.8 +/- 68.1\% when reaching the temperature 50 degrees C. This might be due to heat-induced haemolysis of the red blood cells, resulting in free light absorbing haemoglobin in the surrounding plasma and thus higher effective light absorption.
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| 7. |
- Sohler, D., et al.
(författare)
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Yrast states of the proton drip line nucleus 106 Sb
- 1999
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Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993 .- 0556-2813 .- 1089-490X. ; 59:3, s. 1324-1327
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Tidskriftsartikel (refereegranskat)abstract
- Yrast states of [Formula Presented] have been investigated in the [Formula Presented] reaction using in-beam [Formula Presented]-spectroscopic methods and in the [Formula Presented] reaction performing delayed [Formula Presented] and conversion electron studies. A new isomeric state was found at 103 keV with [Formula Presented] The number of states and transitions in the proposed level scheme have been doubled. The experimental results are discussed within the framework of the shell model. © 1999 The American Physical Society.
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| 9. |
- Tajvidi, Nader
(författare)
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Characterisation and Some Statistical Aspects of Univariate and Multivariate Generalised Pareto Distributions
- 1996
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Extreme value theory is about the distributions of very large or very small values in a time series or stochastic process. This has numerous applications connected with environmental science, civil engineering, materials science and insurance. A rather recent approach for modelling extreme events is the so called peak over threshold (POT) method. The generalised Pareto distribution (GPD) is a two-parameter family of distributions which can be used to model exceedances over a threshold. This thesis consists of three papers. The main focus is on some theoretical and applied statistical issues of univariate and multivariate extreme value modelling. In the first paper we compare the empirical coverage of standard bootstrap and likelihood-based confidence intervals for the parameters and 90\%-quantile of the GPD. By applying a general method of D. N. Lawley, small sample correction factors for likelihood ratio statistics of the parameters and quantiles of the GPD have been calculated. The article also investigates the performance of some bootstrap methods for estimation of accuracy measures of maximum likelihood estimators of parameters and quantiles of the GPD. In the second paper we give a multivariate analogue of the GPD and consider estimation of parameters in some specific bivariate generalised Pareto distributions (BGPD's). We generalise two of existing bivariate extreme value distributions and study maximum likelihood estimation of parameters in the corresponding BGPD's. The procedure is illustrated with an application to a bivariate series of wind data. The main interest in the thesis has been on practicality of the methods so when a new method has been developed, it's performance has been studied with the help of both real life data and simulations. In the third paper we use three previous articles as examples to illustrate difficulties which might arise in application of the theory and methods which may be used to solve them. A common theme in these articles is univariate and multivariate generalised Pareto distributions. However, the discussed problems are of a rather general nature and demonstrate some typical tasks in applied statistical research. We also discuss a general approach to design and implementation of statistical computations.
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| 10. |
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Users in Action. Stories of Users and Telematics in Everyday Life
- 1999
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Samlingsverk (redaktörskap) (övrigt vetenskapligt/konstnärligt)abstract
- Detta är en antologi som består av exempel på empiriska studier där äldre människors varit involverade som subjekt. Resultatet visar att äldres teknikanvändning i vardagen problematiseras på tre nivåer. den första nivån fokuserar konstruktionen och utformningen av artefakten; den andra nivån användningen av tekniken i den vardagliga kontexten; den tredje nivån relationen mellan teknikutvecklingen och användaren som samhällsvarelse.
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