| 1. |
- Choularton, T. W., et al.
(författare)
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The Great Dun Fell Cloud Experiment 1993 : An overview
- 1997
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Ingår i: Atmospheric Environment. - 1352-2310. ; 31:16, s. 2393-2405
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Tidskriftsartikel (refereegranskat)abstract
- The 1993 Ground-based Cloud Experiment on Great Dun Fell used a wide range of measurements of trace gases, aerosol particles and cloud droplets at five sites to study their sources and sinks especially those in cloud. These measurements have been interpreted using a variety of models. The conclusions add to our knowledge of air pollution, acidification of the atmosphere and the ground, eutrophication and climate change. The experiment is designed to use the hill cap cloud as a flow-through reactor, and was conducted in varying levels of pollution typical of much of the rural temperate continental northern hemisphere in spring-time.
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| 2. |
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| 3. |
- Klefsgård, Rosemarie, et al.
(författare)
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Quality of life associated with varying degrees of chronic lower limb ischaemia: comparison with a healthy sample
- 1999
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Ingår i: European Journal of Vascular and Endovascular Surgery. - : Elsevier BV. - 1532-2165 .- 1078-5884. ; 17:4, s. 319-325
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: To assess quality of life in patients with varying degrees of ischaemia in comparison with controls, and to determine whether the degree of lower limb ischaemia and sense of coherence were associated with quality of life. MATERIALS AND METHODS: 168 patients, including 93 claudicants and 75 patients with critical ischaemia and 102 controls were studied. Quality of life was assessed using the Nottingham Health Profile in addition to the Sense of Coherence scale. MAIN RESULTS: Patients with lower limb ischaemia scored significantly reduced quality of life in all aspects compared to controls. Pain, physical mobility and emotional reactions were the significant independent factors when using logistic regression analysis. The grade of disease and low sense of coherence were significantly associated with low quality of life. Increasing lower limb ischaemia significantly conferred worse pain, sleeping disturbances and immobility. CONCLUSION: This study showed that the quality of life was impaired among patients with lower limb ischaemia, in all investigated respects. The degree to which quality of life was affected seems to represent an interplay between the grade of ischaemia and the patient's sense of coherence. This suggests the need for a multidimensional assessment prior to intervention.
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| 4. |
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| 5. |
- Aberg, D, et al.
(författare)
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Ultra-shallow thermal donor formation in oxygen-containing ambient
- 1998
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Ingår i: Physica status solidi. B, Basic research. - 0370-1972 .- 1521-3951. ; 210, s. 527-532
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Tidskriftsartikel (refereegranskat)abstract
- Czochralski-grown phosphorus-doped (approximate to 2 x 10(14) cm(-3)) silicon wafers have been annealed in nitrogen, wet nitrogen, argon, oxygen, and vacuum ambients at 470 degrees C for times up to 500 h. Sample characterization was made with capacitance-voltage, four-point probe, DLTS, thermally stimulated capacitance, admittance spectroscopy, secondary ion-mass spectrometry, and Fourier transform infrared spectroscopy. This study finds a strong relation between the previously reported ultra-shallow thermal donors (USTDs) and shallow thermal donors (STDs), and it is shown that the net concentration of thermally formed donors is independent on annealing ambient within the experimental accuracy. It was found that the majority of formed donors for long anneals consisted of either STDs or USTDs, however, it was found that oxygen-containing ambient is indispensable for forming USTDs.
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| 6. |
- Aberg, D, et al.
(författare)
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Ultrashallow thermal donor formation in silicon by annealing in ambient oxygen
- 1999
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Ingår i: Journal of Applied Physics. - 0021-8979 .- 1089-7550. ; 85, s. 8054-8059
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Tidskriftsartikel (refereegranskat)abstract
- Czochralski-grown silicon wafers doped with phosphorus (similar to 10(14) cm(-3)) have been annealed in nitrogen, wet nitrogen, oxygen, argon, and vacuum ambients at 470 degrees C for times up to 500 h. Sample characterization was made using predominantly electrical techniques such as admittance spectroscopy and thermally stimulated capacitance measurements but also secondary ion mass spectrometry (SIMS) and Fourier transform infrared spectroscopy were employed. In all samples, an increasing concentration of free carrier electrons is observed with increasing annealing time, reaching a maximum of similar to 10(16) cm(-3) at 100 h. For durations in excess of 100 h gradual decrease of the free electron concentration takes place except for the samples treated in wet nitrogen and oxygen atmospheres, which display donors stable even after 200 h. These stable centers are found to have shallower donor level positions in the energy band gap (similar to 25 meV below the conduction band edge E-c) than those of the centers formed in vacuum, argon, and nitrogen atmospheres (similar to 35 meV below E-c). The latter centers are associated with the well-established shallow thermal donors (STDs) while the origin of the former ones, which are labeled ultrashallow thermal donors (USTDs) is less known. However, on the basis of a wealth of experimental results we show that the USTDs are most likely perturbated STDs modified through interaction with fast-in diffusing oxygen species, possibly oxygen dimers. Further, comparison between the electrical data and the SIMS measurements reveals unambiguously that neither the STD nor the USTD centers involve nitrogen, in contrast to recent suggestions in the literature. (C) 1999 American Institute of Physics. [S0021-8979(99)06512-3].
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| 7. |
- Anderbrant, O., et al.
(författare)
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Electrophysiological and morphological characteristics of pheromone receptors in male pine sawflies, Diprion pini (Hymenoptera : Diprionidae), and behavioural response to some compounds
- 1995
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Ingår i: Journal of Insect Physiology. - : Elsevier BV. - 0022-1910. ; 41:5, s. 395-401
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Tidskriftsartikel (refereegranskat)abstract
- The morphology and physiology of pheromone receptors on the antennae of male pine sawflies, Diprion pini L., were investigated. Using scanning electron microscopy, five sensillar types were recognized. The type shown to be pheromone sensitive has a long (50-70 μm) cuticular hair, is single-walled, and is innervated by 8 or 9 sensory cells as revealed by transmission electron microscopy. Electroantennography (EAG) showed similar activity of the acetate and propionate of (2S,3R,7R)-3,7-dimethyl-2-tridecanol, precursor of the main constituent of the female-produced sex pheromone. No other isomer induced any significant response. Single-sensillum recordings confirmed the results of the EAG, and also showed that several neurons were excited by the active compound. EAG recordings and combined gas chromatographic-electroantennographic detection indicated that esters of three 3,7-dimethyl-2-pentadecanol (diprionol) isomers were active, but field tests could not demonstrate any behavioural effect. Diprionol esters are used as sex pheromones by all other pine sawflies investigated so far, and D. pini is thus the first diprionid species shown to use a different sex pheromone.
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| 8. |
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| 9. |
- Hallberg, Eva C., 1966, et al.
(författare)
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Chemical and lectin-gold electron microscopical studies of the expression of the Galalpha1-determinant in the pig aorta.
- 1998
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Ingår i: Xenotransplantation. - 0908-665X. ; 5:4, s. 246-56
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Tidskriftsartikel (refereegranskat)abstract
- In the xenotransplantation research field, pig aortic endothelial cells are frequently used in different model systems, e.g., for the study of the xenoantibody-antigen reaction. The Gal(alpha1),3Gal determinant is the major target for human xenoreactive antibodies in pig tissue. Characterisation of the Gal(alpha1)- distribution in pig aortic endothelial cells is thus important for understanding the reaction occurring at the endothelial cells during the xenorejection. We have determined the complete structure of the major Gal(alpha1),3Gal terminated glycolipid, Gal(alpha1),3nLc4Cer. Structural studies were performed on isolated glycosphingolipids by mass spectrometry and NMR spectroscopy. The results show a predominance of the pentasaccharide among the Gal(alpha1)-terminated glycolipids but also the presence of several Gal(alpha1)-terminated glycolipids with extended carbohydrate core chains. Ultrastructural localisation of the Galalpha1-antigen in pig aorta was done by lectin-gold electron microscopic studies of aortic wall sections using the Griffonia simplicifolia isolectin B4. Gal(alpha1)-determinants are predominantly localised on the luminal surface of pig aortic endothelial cells and endothelial cells of vasa vasorum and, to a lesser extent, vascular subendothelium.
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| 10. |
- Hallberg, K. B., et al.
(författare)
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Arsenic toxicity is not due to a direct effect on the oxidation of reduced inorganic sulfur compounds byThiobacillus caldus
- 1996
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Ingår i: FEMS Microbiology Letters. - 0378-1097 .- 1574-6968. ; 145:3, s. 409-414
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Tidskriftsartikel (refereegranskat)abstract
- Thiobacillus caldus is a moderately thermophilic acidophile which has been implicated in the biooxidation of arsenic containing mineral sulfides. The toxic effects of arsenic on this bacterium are presented here. Addition of arsenite to a growing culture of T. caldus caused a transient increase in the optical density of the culture while causing a simultaneous decrease in cell viability. The increase in optical density was shown to be due to the formation of extracellular sulfur. The oxidation rates of tetrathionate and thiosulfate were decreased by increasing concentrations of arsenite, while in a culture induced to arsenic resistance the rates were not as adversely effected. Sulfur oxidation was also inhibited to the same extent as tetrathionate oxidation, with the oxidation of solid sulfur being slightly more effected than the oxidation of sulfur dissolved in acetone. Thus, bactericidal arsenite causes a transient formation of extracellular sulfur in the culture supernatant of T. caldus yet the toxicity of arsenite is not due to direct inhibitory effects on reduced inorganic sulfur compound oxidation by these bacteria.
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