| 1. |
- Håkansson, H., et al.
(författare)
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In vivo and in vitro toxicity of fractionated fish lipids, with particular regard to their content of chlorinated organic compounds
- 1991
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Ingår i: Pharmacology and Toxicology. - : Wiley. - 0901-9928 .- 1600-0773. ; 69:6, s. 459-471
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Tidskriftsartikel (refereegranskat)abstract
- Six different lipid matrices (the intact lipid (IL), four lipid fractions with different polarity, and the free fatty acids (FFAs) obtained by hydrolysis of the triacylglycerol (TAG) containing fraction) were obtained from salmon (Salmo salar) and eel (Anguilla anguilla), each collected at a contaminated and a comparatively uncontaminated catch site along the coast of Scandinavia. The lipid matrices were studied in toxicological test systems representing various biological functions of different organ systems from several species and trophic levels. The results were evaluated with particular respect to the concentrations of extractable organically bound chlorine (EOCl) in the matrices tested. In some test systems, the specimens with a higher EOCl concentration appeared to be more toxic. For example, the TAG containing fraction (F2) from Idefjord eel, having a higher EOCl content than F2 from Oslofjord eel, reduced the number and hatchability of eggs laid by zebrafish. Both IL and F2 of Idefjord eel increased mortality and reduced the oxygen/nitrogen-ratio in blue mussels. Non-polar compounds (F1) from Bothnian Sea salmon induced 7-ethoxyresurofin O-deethylase (EROD) activity in rainbow trout hepatocytes, whereas F1 from Senja salmon did not. F1 from Bothnian Sea salmon also reduced the number of T-cells in foetal mouse thymus anlagen in vitro compared with the cell number in anlagen exposed to F1 from Senja salmon. A positive correlation between EOCl concentration and test response was found for EROD activity in rainbow trout hepatocytes and for ATP-leakage in Erlich ascites tumour cells when testing the phospolipid containing fraction (F4). However, in most test systems the fish oils, irrespective of EOCl content, were of low toxicity, and the observed effects need to be verified in future studies.
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| 2. |
- Hammar, M., et al.
(författare)
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Morphology and atomic structure of the sputtered and annealed Mo3Si and Cr3Si (110) surfaces
- 1994
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Ingår i: Physical Review B. - 0163-1829. ; 50:23, s. 17639-17642
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Tidskriftsartikel (refereegranskat)abstract
- Scanning tunneling microscopy was used to study the sputtered and annealed (110) surfaces of Mo3Si and Cr3Si. Both surfaces show extended and atomically flat terraces, but in the case of Mo3Si there is also a uniform distribution of Mo crystallites. This difference in morphology is discussed in terms of different preferential sputtering effects. In both cases, measured step heights show that the ideally bulk-truncated surfaces are either purely Si or metal terminated. Atomically resolved images suggest that the Mo3Si surface is Si terminated, but although no atomic resolution could be obtained for the Cr3Si surface, there are indications that this surface is instead metal terminated. © 1994 The American Physical Society.
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| 3. |
- Håkansson, K. L., et al.
(författare)
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High-resolution core-level studies of VC0.80 surfaces
- 1993
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Ingår i: Physical Review B. - 0163-1829. ; 47:16, s. 10769-10774
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Tidskriftsartikel (refereegranskat)abstract
- High-resolution core-level-photoemission investigations of the (100), (111)-1×1, and (111)-8×1 surfaces of VC0.80 using synchrotron radiation are reported. Surface-shifted C 1s levels were observed on all three surfaces while surface-shifted V 2p levels could not be identified on any of the surfaces. The surface core-level shifts were extracted using a curve-fitting procedure. For the major surface-shifted component which was identified on all three surfaces, a shift of -0.33(±0.02) eV was determined. For the (111)-8×1 surface a second shifted component having a shift of +0.44(±0.02) eV was identified. © 1993 The American Physical Society.
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| 5. |
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| 6. |
- Gaillard, Marie-Jose, et al.
(författare)
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A late Holocene record of land-use history, soil erosion, lake trophy and lake-level fluctuations at Bjäresjösjön (South Sweden) changes in southern Sweden
- 1991
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Ingår i: Journal of Paleolimnology. - 0921-2728 .- 1573-0417. ; 6, s. 51-81
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Tidskriftsartikel (refereegranskat)abstract
- Land-use history, soil ersosion, lake trophy and lake-level fluctuations during the last 3000 years werereconstructed through a multidisciplinary palaeolimnological study (pollen, plant macrofossils, diatoms,physical and chemical analysis, magnetic measurements and radiometric methods) of a small eutrophiclake in southern Sweden (Bj~resjOsjOn, Scania). There are striking responses in diatom, chemical,sediment yield and magnetic records to land-use changes documented by pollen analysis or historicalsources, and to lake-level changes identified from sedimentary changes. Our multidisciplinary approachassists interpretation of the processes controlling long-term changes and separation of the effects ofdifferent factors (land-use changes, lake-level fluctuations) on individual biostratigraphical records.Climate has controlled processes in the lake indirectly, through lake-level fluctuations, from the LateBronze Age to the Viking Age (700 BC-AD 800). Since the Viking Age, land-use controlled most of thechanges observed in the lake's development and soil erosion processes. Major changes in lake developmentoccurred during the last 200 years, due to a drastic increase in soil erosion and water eutrophicationduring a period of agricultural modernization.
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| 7. |
- Gaillard, Marie-Jose, et al.
(författare)
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A multidisciplinary study of Lake Bjäresjö (S Sweden): land-use history, soil erosion, lake trophy and lake-level fluctuations during the last 3000 years
- 1991
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Ingår i: Hydrobiologia. - 0018-8158 .- 1573-5117. ; 214, s. 107-114
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Tidskriftsartikel (refereegranskat)abstract
- The lake Bjaresjosjon, Southern Scania, Southern Sweden, was studied in the context of the project 'The cultural landscape of the past 6000 years in Southern Sweden'. Pollen, plant macrofossils, diatoms, physical and chemical analysis, magnetic measurements and radiometric methods (Pb-210, C-14) have been used to study palaeoecological changes, i.e. climate, land use, lake trophy and soil erosion during the past 3000 years. This multidisciplinary study shows striking responses of diatom communities, physical and chemical characteristics, sediment yields and magnetic parameters to land-use changes and lake-level fluctuations. Moreover, the latter are closely related to the settlement history at the site, inferred from archaeological records and historical sources. Before 650 AD, the limnological development was affected mainly by lake-level fluctuations, but partly also by human impact (extensive forest clearings and dominant pastoral farming). With the expansion of arable farming (around 650 AD), human impact on the landscape was the major factor influencing soil erosion processes in the catchment and limnological changes in the lake.
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| 8. |
- Hammar, M., et al.
(författare)
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Surface atomic structure of reconstructed VC0.8(111) studied with scanning tunneling microscopy
- 1992
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Ingår i: Physical Review B. - 0163-1829. ; 45:11, s. 6118-6123
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Tidskriftsartikel (refereegranskat)abstract
- Scanning tunneling microscopy has been performed on the reconstructed polar surface of substoichiometric VC0.80(111). A mixture of (8×1) and (3 × 3) R30°reconstructed areas was found. The (8×1) periodicity could be determined to be the result of a square-lattice surface layer superimposed on the hexagonal substrate. As this square lattice must have its origin in strong and directed in-plane bonds with the relatively large length of about 2.9, it can be deduced to consist of vanadium atoms. Lateral positions of these vanadium surface atoms with respect to the substrate are suggested from the measured surface corrugation. The (3 × 3) R30°structure was found in small triangular areas which can, due to the measured step heights between the two reconstructions, be believed to be carbon terminated. The occurrence of a reconstructed surface with a reduced atomic concentration is in contrast to what is known for TiC(111) and NbC(111), both having stable (1×1) surfaces. A qualitative explanation for this difference is suggested. © 1992 The American Physical Society.
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| 9. |
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| 10. |
- Håkansson, L, et al.
(författare)
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Migratory responses of eosinophil and neutrophil granulocytes from patients with asthma
- 1990
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Ingår i: Journal of Allergy and Clinical Immunology. - : Elsevier BV. - 0091-6749 .- 1097-6825. ; 85:4, s. 743-750
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Tidskriftsartikel (refereegranskat)abstract
- In the present study the migratory function of eosinophil and neutrophil granulocytes from patients with asthma were investigated. Fifty-seven patients with asthmatic disease of varying severity were included. Eosinophil and neutrophil chemotactic responses to 5% pooled normal human serum (NHS), 5% allergen-challenge serum, 2.5% zymosan-activated serum, N-formyl-methionyl-leucyl-phenylalanine (10 nmol/L), chemokinetic responses to albumin (2 gm/L) and 5% NHS, and the eosinophil and neutrophil chemotactic and chemokinetic activities of serum were investigated. Eosinophils from patients with asthma demonstrated significantly (p less than 0.02) increased chemotactic responses to allergen-challenge serum, zymosan-activated serum, and N-formyl-methionyl-leucyl-phenylalanine, compared with eosinophils from references. The chemokinetic responses to albumin and NHS were increased (p less than 0.01) by eosinophils from the patients who had blood eosinophilia (greater than 400 X 10(6)/L). Sera from the patients with asthma demonstrated raised eosinophil chemotactic activity (p less than 0.001) and raised eosinophil and neutrophil chemokinetic activity (p less than 0.001). The eosinophil chemokinetic activity of serum was correlated to the relative peak expiratory flow rate of the patients (r = -0.43; p less than 0.02). The increased migratory responses were specific for the eosinophils, since the migratory responses of their neutrophils were not altered compared with that of the references. These results suggest that the eosinophils from the patients with asthma had been exposed to a priming mechanism in vivo.
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