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- Johansson, Pernilla, et al.
(author)
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Fältförsök med träskyddsmedel för klass AB. Delrapport nr 2. Resultat efter 5 års exponering. Nordic Wood projekt nr 98056
- 2001
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Reports (peer-reviewed)abstract
- Since 1994 there are restrictions in Sweden on the use of chromium and arsenic containing wood preservatives. These preservatives are now in principle allowed for use in ground contact and water only. The use of chromium and arsenic free preservatives has increased and dominates the Swedish market for commodities above ground (Nordic wood preservation class AB). As the knowledge of the performance of these preservatives is limited, a field trial was set up in order to get more information about the durability in ground and above ground, discolouration by staining fungi, leaching, weathering and corrosion on fasteners in contact with the treated wood. Samples were treated according to class AB in commercial treating plants with the following preservatives: Basilit Bauholz KVD, Impralit KDS, Kemwood ACQ 1900, Tanalith E, Wolmanit CX-S and Wolmanit CX-8. Untreated spruce and heartwood of pine and larch were also included in the trial. In addition to testing according to EN 252 and ENV 12037 (lap-joint), both somewhat modified, testing was also carried out according to methods specially designed for this trial. After five years exposure the results show that: · No treated samples exposed above ground have yet been attacked and very few untreated samples only have been severely attacked by wood destroying fungi. There is thus some concern that the methods used, and in particular the lap-joint method, are not suitable for above ground testing in temperate climates. · The tests in ground indicate that with increasing copper content in the treated wood the better is the performance. · Heartwood of larch performs better than heartwood of pine in the in ground tests. On contrary, heartwood of pine shows better decay resistance than heartwood of larch in the above ground tests. · All samples are more or less attacked by bluestain fungi. Untreated samples are severely attacked. · Stainless steel has the best performance against corrosion. Wood treated with Kemwood ACQ 1900 and Wolmanit CX-8 seems to accelerate the corrosion of most other fastener materials. · The leaching of the chromium and arsenic free preservatives seems to be substantial whereas the leaching from CCA-treated references is little or moderate. For wood preservatives containing copper and an organic active ingredient, copper seems to be less susceptible to leaching then the organic component for which not only leaching but also chemical decomposition may take place.
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| 3. |
- Byström, Pernilla, 1976, et al.
(author)
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Appraised psychological workload, musculoskeletal symptoms, and the mediating effect of fatigue: A structural equation modeling approach.
- 2004
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In: Scandinavian Journal of Psychology. - : Wiley. ; 45:4, s. 331-341
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Journal article (peer-reviewed)abstract
- The aim of the present study was to test two structural models of the relationship between appraised psychologicla workload and musculoskeletal symptoms from the neck, shoulder, and upper and lower back with different aspects of perceived fatigue as mediating variables. In this cross-sectional study a questionnaire survey was conducted among employees at three Swedish assembly plants (n=305). The proposed models were tested for one general fatigue dimension - lack of energy - and four specific fatigue dimensions - physical discomfort, physical exertion, lack of motivation, and sleepiness - using structural equation modeling. The results indicate that the role of perceived fatigue in the relationship between appraised workload and musculoskeletal symptoms is different for different aspects of fatigue. The general fatigue dimension, lack of energy, does not mediate the relationship. As regards the specific fatigue dimensions, the relationship is partially mediated by physical discomfort and lack of motivation but not by physical exertion or sleepiness. Appraised psychological workload has a unique effect on musculoskeletal symptoms not mediated by fatigue.
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| 5. |
- Häggström Rudolfsson, Stina, et al.
(author)
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Localized expression of angiopoietin 1 and 2 may explain unique characteristics of the rat testicular microvasculature.
- 2003
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In: Biology of Reproduction. - : Oxford University Press (OUP). - 0006-3363 .- 1529-7268. ; 69:4, s. 1231-7
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Journal article (peer-reviewed)abstract
- The testicular vasculature is unique in several ways. The unfenestrated endothelial cells constitute one part of the blood-testis barrier, and testicular microvessels are normally resistant to inflammation mediators. At the same time that angiogenic factors and inflammation mediators are constitutively produced, the proportion of proliferating endothelial cells is considerably higher than in other organs, but new blood vessels are not formed. Hormonal stimulation of the testis with hCG increase endothelial cell proliferation, vascular permeability, and sensitivity to locally injected inflammation mediators. In the present study, we examined whether local expression of angiopoietin (ang) 1, an inhibitor of vascular leakage and sprouting angiogenesis, and its antagonist, ang 2, could be involved in establishing this vascular phenotype. Using reverse transcription-polymerase chain reaction and immunohistochemistry, we demonstrate that testicular vascular endothelial growth factor-A (VEGF-A), ang 1, ang 2, and the ang-receptor tie 2 are expressed in the testis and that hormonal stimulation with hCG is accompanied by increased expression of VEGF-A and ang 2. The ang 1 protein is expressed in testicular microvessels under basal conditions, and it is largely unaffected after hCG stimulation. Expression of ang 2 in microvessels, in contrast, is low under basal conditions and is up-regulated by hCG. Intratesticular injection of human recombinant ang 1 protein inhibits hCG-induced increase in vascular permeability. Injection of ang 2 in the testis increases endothelial cell proliferation and the volume of the interstitial space. We therefore suggest that ang 1 stabilizes testicular microvessels under basal conditions and that a shift in this balance caused by increased ang 2, together with increased VEGF-A, allows vascular leakage, high endothelial cell proliferation, and presumably, vascular growth after hormonal stimulation.
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| 8. |
- Johansson, Pernilla
(author)
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Mögel på nytt och begagnat byggnadsvirke
- 2003
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Reports (peer-reviewed)abstract
- Mould growth on new and used construction timber The growth of mould on building materials varies in both rate and extent from one type of material to another, depending on the nutrients in the material and on the local conditions. In this respect, wood is a sensitive building material. This investigation has compared the growth of mould on new and on used timber under high humidity conditions (90-95 % RH, 22 °C) in a climate test chamber. The used timber was more quickly attacked by mould than was the new timber, regardless of whether it was simply placed in the chamber or was first sterilised and then sprayed with spores before being put into the chamber. However, when the surface of the used timber samples was sawn off, it behaved in the same way as new timber. The results show that old timber cannot simply be incorporated in new structures without a second thought, but that it can work just as well as new timber if the exposed surface of the old timber is first removed.
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