| 71. |
- Greczynski, G., et al.
(författare)
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Electronic structure of pristine and sodium doped poly(p-pyridine)
- 2001
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Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 114:9, s. 4243-4252
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Tidskriftsartikel (refereegranskat)abstract
- Ultraviolet spectroscopy (UPS) and x-ray photoelectron spectroscopy (XPS) were used to study the valence electronic structures of pristine and sodium doped poly (p-pyridine) (PPY). The UPS spectra were analyzed by studying the density-of-valence-states (DOVS) derived from quantum chemical calculations. The electronic band structure of the PPY chains was also theoretically investigated using the valence effective Hamiltonian (VEH) method. The theoretical approach was found to be more accurate in describing the electronic structure of PPY.
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| 72. |
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| 73. |
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| 74. |
- Johansson, Elisabeth, et al.
(författare)
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Methane emissions from a constructed wetland treating wastewater : Seasonal and spatial distribution and dependence on edaphic factors
- 2004
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Ingår i: Water Research. - : Elsevier BV. - 0043-1354 .- 1879-2448. ; 38:18, s. 3960-3970
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Tidskriftsartikel (refereegranskat)abstract
- Constructed wetlands for wastewater treatment have many advantages. They can be used for several purposes, for example, to reduce levels of organic matter and nutrients, and to retain toxic metals. However, most wetlands are inherently net sources of gaseous compounds like methane and nitrous oxide, which are of environmental concern due to their rapid current accumulation in the atmosphere and their potent global warming capacity. In order to determine the flux of methane from a constructed wetland a study was conducted over two growth seasons on a pilot scale wetland constructed to reduce nutrient levels in secondary treated wastewater. The emissions for the spring to autumn period averaged 141 mg CH4 m-2 d-1 (S.D.=187), ranging from consumption of 375 mg CH4 m-2 d-1 to emissions of 1739 mg CH4 m-2 d-1. The spatial and temporal variations were large, but could be accounted for by measured environmental factors. Among these factors, sediment and water temperatures were significant in all cases and independent of the scale of analysis (r2 up to 0.88).
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| 75. |
- Johansson, G. A., et al.
(författare)
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Compact soft x-ray reflectometer based on a line-emitting laser-plasma source
- 2001
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Ingår i: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 72:1, s. 58-62
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Tidskriftsartikel (refereegranskat)abstract
- We describe a compact soft x-ray reflectometer for in-house characterization of water-window multilayer optics. The instrument is based on a line-emitting, liquid-jet, laser-plasma source in combination with angular scanning of the studied multilayer optics. With a proper choice of target liquid and thin-film filters, one or a few lines of well-defined wavelength dominate the spectrum and multilayer periods are measured with an accuracy of 0.003 nm using a multi-line calibration procedure. Absolute reflectivity may also be estimated with the instrument. The typical measurement time is currently 10 min. Although the principles of the reflectometer may be used in the entire soft x-ray and extreme ultraviolet range, the current instrument is primarily directed towards normal-incidence multilayer optics for water-window x-ray microscopy, and is thus demonstrated on W/B4C multilayers for this wavelength range.
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| 76. |
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| 77. |
- Johnsson, Filip, 1960, et al.
(författare)
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An experimental study of in-furnace processes and dynamic behaviour of a 235 MWe CFB boiler
- 2004
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Ingår i: VGB PowerTech. - 1435-3199. ; 84:3, s. 82-87
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Tidskriftsartikel (refereegranskat)abstract
- In a project funded by the 5th Framework Programme of the European Union, a 235 MWe Circulating Fluidized Bed (CFB) boiler is investigated with respect to in-furnace processes and dynamic response to load changes. The purpose of the project is to assess the insufficiently known features of large-scale CFB boilers. The furnace of the boiler has a cross-section of 21 x 10 meters and a height of 44 meters. The boiler is located in Turow, Poland, and is operated on a local brown coal.The project is unique in that several measurement ports were opened in the walls of the large CFB furnace for measurements in various locations inside the furnace. Also, a number of techniques were employed with new probes developed for this type of measurements to form a basis for studies of hydrodynamic processes as well as local variations in gas components (such as O2, CO, THC) and solid bed materials. The paper describes the measurement techniques and provides examples of results obtained from the in-situ measurements and from the dynamic response study.
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| 78. |
- Kjellberg, L, et al.
(författare)
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Smoking, diet, pregnancy and oral contraceptive use as risk factors for cervical intra-epithelial neoplasia in relation to human papillomavirus infection.
- 2000
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Ingår i: British Journal of Cancer. - : Springer Science and Business Media LLC. - 0007-0920 .- 1532-1827. ; 82:7, s. 1332-8
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Tidskriftsartikel (refereegranskat)abstract
- Smoking, nutrition, parity and oral contraceptive use have been reported as major environmental risk factors for cervical cancer. After the discovery of the very strong link between human papillomavirus (HPV) infection and cervical cancer, it is unclear whether the association of these environmental factors with cervical cancer reflect secondary associations attributable to confounding by HPV, if they are independent risk factors or whether they may act as cofactors to HPV infection in cervical carcinogenesis. To investigate this issue, we performed a population-based case-control study in the Vasterbotten county of Northern Sweden of 137 women with high-grade cervical intra-epithelial neoplasia (CIN 2-3) and 253 healthy age-matched women. The women answered a 94-item questionnaire on diet, smoking, oral contraceptive use and sexual history and donated specimens for diagnosis of present HPV infection (nested polymerase chain reaction on cervical brush samples) and for past or present HPV infections (HPV seropositivity). The previously described protective effects of dietary micronutrients were not detected. Pregnancy appeared to be a risk factor in the multivariate analysis (P < 0.0001). Prolonged oral contraceptive use and sexual history were associated with CIN 2-3 in univariate analysis, but these associations lost significance after taking HPV into account. Smoking was associated with CIN 2-3 (odds ratio (OR) 2.6, 95% confidence interval (CI) 1.7-4.0), the effect was dose-dependent (P = 0.002) and the smoking-associated risk was not affected by adjusting for HPV, neither when adjusting for HPV DNA (OR 2.5, CI 1.3-4.9) nor when adjusting for HPV seropositivity (OR 3.0, CI 1.9-4.7). In conclusion, after taking HPV into account, smoking appeared to be the most significant environmental risk factor for cervical neoplasia.
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| 79. |
- Korotkov, A., et al.
(författare)
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Changes in human regional cerebral blood flow following hypertonic saline induced experimental muscle pain : a positron emission tomography study
- 2002
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Ingår i: Neuroscience Letters. - 0304-3940 .- 1872-7972. ; 335:2, s. 119-123
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Tidskriftsartikel (refereegranskat)abstract
- A positron emission tomography imaging study was performed on 16 healthy volunteers to reveal changes in cortical activation during acute muscle pain induced by intra-muscular injection of hypertonic saline into the left triceps brachii muscle. Changes in regional cerebral blood flow (rCBF) were measured with the use of [(15)O] labelled water during 'Rest1', 'Needle' (insertion of a needle without injection), 'Rest2' and 'Pain' conditions. Differences in rCBF were found in the comparison of Pain and Needle, and Pain and Rest2 conditions, revealing activation of the contralateral insula and putamen. The results are discussed with respect to possible differences in brain processing of muscle and cutaneous noxious inputs.
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| 80. |
- Kronqvist, M, et al.
(författare)
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A hypoallergenic derivative of the major allergen of the dust mite Lepidoglyphus destructor, Lep d 2.6Cys, induces less IgE reactivity and cellular response in the skin than recombinant Lep d 2
- 2001
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Ingår i: International archives of allergy and immunology. - : S. Karger AG. - 1018-2438 .- 1423-0097. ; 126:1, s. 41-49
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Tidskriftsartikel (refereegranskat)abstract
- <i>Background:</i> The major allergen of the dust mite<i> Lepidoglyphus destructor</i>, Lep d 2, has been produced as a recombinant allergen (rLep d 2) with IgE reactivity both in vivo and in vitro. A modified form of rLep d 2 (rLep d 2.6Cys) obtained by site-directed mutagenesis has been shown to have a reduced IgE reactivity in vitro. In this study we have compared the ability of rLep d 2 and rLep d 2.6Cys to elicit positive skin prick tests and cellular responses among<i> L. destructor</i>-sensitized subjects. <i>Methods:</i> Seventeen subjects were skin prick-tested with rLep d 2, rLep d 2.6Cys, histamine and negative controls and 17–20 h later skin biopsy specimens were taken from the skin prick-tested sites. The biopsy specimens were stained immunohistochemically for EG2+, CD3+, CD1a+, mast cell tryptase+, and IgE+ cells. Dermal cell infiltrates were judged in hematoxylin and eosin staining. Total IgE and allergen-specific IgE were determined by CAP-RAST. <i>Results:</i> Compared to rLep d 2, rLep d 2.6Cys induced significantly smaller and fewer skin prick test reactions (p < 0.001) and dermal cell infiltrates (p < 0.05). Further, rLep d 2.6Cys induced fewer EG2+ cells (p < 0.001) but more tryptase+ cells (p < 0.05) than rLep d 2. A positive RAST to rLep d 2 was obtained for 88.2% of the subjects, while only 35.2% displayed a positive RAST to rLep d 2.6Cys. <i>Conclusion:</i> This study demonstrates that rLep d 2.6Cys is less able to evoke IgE-mediated reactions and cellular responses, as measured both in skin and in serum, than rLep d 2. In the future this hypoallergenic derivative may be a promising candidate molecule for immunotherapy of <i>L. destructor</i>-allergic patients.
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