| 1. |
- Bolinsson, J, et al.
(författare)
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Direct observation of atomic scale surface relaxation in ortho twin structures in GaAs by XSTM
- 2009
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Ingår i: Journal of Physics: Condensed Matter. - : IOP Publishing. - 1361-648X .- 0953-8984. ; 21:5
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Tidskriftsartikel (refereegranskat)abstract
- We have studied the (110) GaAs surface of a structure containing ortho twins by cross-sectional scanning tunnelling microscopy and we have compared the experimental results with ab initio density functional theory calculations and STM simulations. Both experimentally and theoretically we find that the surface of different twin crystallites are significantly displaced with respect to each other, parallel to the twin boundary. This result is explained by a surface relaxation of the atoms in the (110) GaAs surface and the difference between the atomic configuration of the ortho twins.
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| 2. |
- Gustafsson, Anders, et al.
(författare)
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Cathodoluminescence Studies of AlGaAs/GaAs Core-Shell Nanowires
- 2005
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Ingår i: Springer Proceedings in Physics. - 0930-8989. ; 107, s. 463-466
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Konferensbidrag (refereegranskat)abstract
- We have studied nanowires with a GaAs core, covered by an AlGaAs shell, using low temperature cathodoluminescence. The main emission from the core is due carbon acceptors, though we observe a weak emission from excitons. A general observation is that the emission is much stronger from the top half of the nanowire. This emission is also more well-defined. The AlGaAs shell emission varies in emission energy and spatial origin in an irregular fashion.
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| 3. |
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| 4. |
- Larsson, Niklas, et al.
(författare)
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Equilibrium sampling through membranes (ESTM) of acidic organic pollutants using hollow fibre modules in continuous steady-state mode.
- 2009
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Ingår i: Chemosphere. - : Elsevier BV. - 1879-1298 .- 0045-6535. ; 76:9, s. 1213-1220
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Tidskriftsartikel (refereegranskat)abstract
- Hollow fibre (HF) membrane modules were applied in continuous mode for equilibrium sampling through membranes (ESTM) of polar organic pollutants. Phenolic compounds (chlorophenols, cresols and phenol) served as model substances and ESTM was tuned towards the measurement of freely dissolved concentrations (C(free)). HF membrane modules were constructed using thin-walled membrane, 1-m module length and low packing density in order to optimise the uptake kinetics of the analytes into the acceptor solution. Such custom made devices were tested and compared to commercially available modules. The former modules performed best for continuous ESTM. The custom made modules provided steady-state equilibrium within 20-40min and enrichment that was in general agreement with calculated distribution ratios between acceptor and sample. In experiments during which sample concentration was changed, acceptor response time to decreased sample concentration was around 30min for custom built modules. In the presence of commercial humic acids, analytes showed lower steady-state enrichment, which is due to a decrease in C(free). Continuous ESTM may be automated and is suggested for use in online determination of C(free) of pollutants and studies on sorption of pollutants. Future studies should include optimisation of the membrane liquid and factors regarding the residence time of the acceptor solution in the fibre lumen. Qualitative aspects of DOM should also be included, as natural DOM can be fractionated. C(free) could be correlated to DOM properties that have previously been shown to influence sorption, such as aromaticity, carboxylic acid content and molecular size.
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| 5. |
- Marttila, Marko, et al.
(författare)
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CD46 is a cellular receptor for all species B adenoviruses except types 3 and 7
- 2005
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Ingår i: Journal of Virology. - : American Society for Microbiology. - 0022-538X .- 1098-5514. ; 79:22, s. 14429-14436
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Tidskriftsartikel (refereegranskat)abstract
- The 51 human adenovirus serotypes are divided into six species (A to F). Adenovirus serotypes from all species except species B utilize the coxsackie-adenovirus receptor for attachment to host cells in vitro. Species B adenoviruses primarily cause ocular and respiratory tract infections, but certain serotypes are also associated with renal disease. We have previously demonstrated that adenovirus type 11 (species B) uses CD46 (membrane cofactor protein) as a cellular receptor instead of the coxsackie-adenovirus receptor (A. Segerman et al., J. Virol. 77:9183-9191, 2003). In the present study, we found that transfection with human CD46 cDNA rendered poorly permissive Chinese hamster ovary cells more permissive to infection by all species B adenovirus serotypes except adenovirus types 3 and 7. Moreover, rabbit antiserum against human CD46 blocked or efficiently inhibited all species B serotypes except adenovirus types 3 and 7 from infecting human A549 cells. We also sequenced the gene encoding the fiber protein of adenovirus type 50 (species B) and compared it with the corresponding amino acid sequences from selected serotypes, including all other serotypes of species B. From the results obtained, we conclude that CD46 is a major cellular receptor on A549 cells for all species B adenoviruses except types 3 and 7.
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| 6. |
- Movérare-Skrtic, Sofia, et al.
(författare)
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Dihydrotestosterone treatment results in obesity and altered lipid metabolism in orchidectomized mice.
- 2006
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Ingår i: Obesity (Silver Spring, Md.). - : Wiley. - 1930-7381 .- 1930-739X. ; 14:4, s. 662-72
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To determine the role of androgen receptor (AR) activation for adipose tissue metabolism. Sex steroids are important regulators of adipose tissue metabolism in men. Androgens may regulate the adipose tissue metabolism in men either directly by stimulation of the AR or indirectly by aromatization of androgens into estrogens and, thereafter, by stimulation of the estrogen receptors. Previous studies have shown that estrogen receptor alpha stimulation results in reduced fat mass in men. RESEARCH METHODS AND PROCEDURES: Orchidectomized mice were treated with the non-aromatizable androgen 5alpha-dihydrotestosterone (DHT), 17beta-estradiol, or vehicle. Vo(2), Vco(2), resting metabolic rate, locomotor activity, and food consumption were measured. Furthermore, changes in hepatic gene expression were analyzed. RESULTS: DHT treatment resulted in obesity, associated with reduced energy expenditure and fat oxidation. In contrast, DHT did not affect food consumption or locomotor activity. Furthermore, DHT treatment resulted in increased high-density lipoprotein-cholesterol and triglyceride levels associated with markedly decreased 7alpha-hydroxylase gene expression, indicating decreased bile acid production. DISCUSSION: We showed that AR activation results in obesity and altered lipid metabolism in orchidectomized mice. One may speculate that AR antagonists might be useful in the treatment of obesity in men.
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| 7. |
- Windahl, Sara H, 1971, et al.
(författare)
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Identification of Target Cells for the Genomic Effects of Estrogens in Bone
- 2007
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Ingår i: Endocrinology. - : The Endocrine Society. - 0013-7227 .- 1945-7170. ; 148:12, s. 5688-95
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Tidskriftsartikel (refereegranskat)abstract
- Estrogen has bone protective effects, but the exact mechanism behind these effects remains unclear. The aim of the present study was to identify the primary target cells in bone for the classical genomic effects of estrogens in vivo. For this purpose we have used reporter mice with a luciferase gene under the control of three estrogen-responsive elements (EREs), enabling detection of in vivo activation of gene transcription. Three-month-old ovariectomized mice were treated with a single dose (50microg/kg) 17beta-estradiol (E2). Luciferase activity was analysed in several tissues and in different bone marrow-derived lymphocyte enriched/depleted preparations using MacsMouse CD19 (for B lymphocytes) or CD90 (for T lymphocytes) MicroBeads. Histological characterization of cells with high luciferase content was performed using immunohistochemistry. Both cortical bone and bone marrow displayed a rapid (within 1h) and pronounced E2-induced increase in luciferase activity. The luciferase activity in total bone marrow and in bone marrow depleted of lymphocytes was increased 6-8 times more than in either B lymphocyte and T lymphocyte enriched cell fractions 4h after the E2-injection, demonstrating that mature lymphocytes are not major direct targets for the genomic effect of estrogens in bone. Immunohistochemistry identified clear luciferase staining in hypertrophic growth plate chondrocytes, megakaryocytes, osteoblasts and lining cells, while no staining was seen in proliferative chondrocyte. Although most of the osteocytes did not display any detectable luciferase staining, a subpopulation of osteocytes both in cortical and trabecular bone stained positive for luciferase. In conclusion, hypertrophic growth plate chondrocytes, megakaryocytes, osteoblasts, lining cells and a subpopulation of osteocytes were identified to respond to estrogen via the classical ERE-mediated genomic pathway in bone. Furthermore, our findings indicate that possible direct estrogenic effects on the majority of osteocytes, not staining positive for luciferase, on proliferative chondrocytes and on mature lymphocytes are mediated by non-ERE actions.
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| 8. |
- Öhrström, Niklas, 1977-, et al.
(författare)
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Visual discrimination between Swedish and Finnish among L2-learners of Swedish
- 2009
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Ingår i: Proceedings, FONETIK 2009. - 9789163348938 ; , s. 150-153
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- A series of speech reading experiments were carried out to examine the ability to discriminate between Swedish and Finnish among L2 learners of Swedish and Spanish as their mother tongue. This group was compared with native speakers of Swedish and a group with no knowledge in Swedish or Finnish. The results showed tendencies, that familiarity with Swedish increased the discrimination ability between Swedish and Finnish.
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