| 1. |
- Andersson, Maria, 1976, et al.
(författare)
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Mild renal ischemia-reperfusion reduces charge and size selectivity of the glomerular barrier
- 2007
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Ingår i: American Journal of Physiology Renal Physiology. - : American Physiological Society. - 0363-6127 .- 1931-857X .- 1522-1466. ; 292:6
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Tidskriftsartikel (refereegranskat)abstract
- Despite recent discoveries of molecules in podocytes, the mechanisms behind most conditions of proteinuria are still poorly understood. To understand more about this delicate barrier, we studied the functional and morphological effects of mild (15 min) renal ischemia-reperfusion injury (IRI). Renal function was studied in rats in vivo, followed by a more detailed analysis of the glomerular barrier in cooled (8 degrees C) isolated perfused kidneys (cIPK). Renal blood flow was quickly restored, whereas the glomerular filtration rate remained halved 30 min after IRI. Tubular cell activity was intact as judged from the unaffected Cr-EDTA U/P concentration ratio. In vivo, the fractional clearance (theta) for albumin increased 16 times. In rats subjected to cIPK starting 30 min after in vivo IRI, theta(albumin) was 15 times and theta(Ficoll_36angstroms) 1.8 times higher than in control cIPKs. According to the heterogeneous charged fiber model, IRI reduced the fiber charge density to 38% of control (P < 0.01, n = 7). Morphometric analysis with electron microscopy did not reveal any changes in the podocytes or the glomerular basement membrane (GBM) after IRI, suggesting more subtle changes of the GBM and/or the endothelial glycocalyx. We conclude that mild renal IRI induces formation of reactive oxygen species, massive proteinuria, and loss of charged fibers with no apparent change in morphology. These novel findings stress the importance of other components of the barrier, such as proteoglycans produced by the glomerular cells, and provide a tentative explanation for the mechanisms behind proteinuria in glomerulonephritis, for example.
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| 2. |
- Alcorta, M., et al.
(författare)
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Nuclear Structure of C-12 from Break-up Studies in Complete Kinematics
- 2009
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Ingår i: AIP Conference Proceedings. - : AIP. - 1551-7616 .- 0094-243X. - 9780735407022 ; 1165, s. 27-30 461
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Konferensbidrag (refereegranskat)abstract
- A complete kinematics study of the B-10(He-3,p alpha alpha alpha) and B-11(He-3,d alpha alpha alpha) reactions has been performed to study the multi-particle break-up of C-12 resonances above the triple-alpha threshold. Four-particle coincidence detection gives us complete information on the direction and energy of the individual alpha particles from the decay of C-12, allowing us to extract new information on the structure of C-12 which we shall present in this contribution. We have observed gamma de-excitation of the T=1 15.11 MeV resonance using charged particle detectors, and have constructed Dalitz plots of the individual resonances in C-12 using the complete kinematics information of the alpha particles which come from their break-up.
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| 3. |
- Kirsebom, O. S., et al.
(författare)
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Observation of gamma-delayed 3 alpha breakup of the 15.11 and 12.71 MeV states in C-12
- 2009
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Ingår i: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 680:1, s. 44-49
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Tidskriftsartikel (refereegranskat)abstract
- The reactions B-10(He-3, p alpha alpha alpha) at 4.9 MeV and B-11(He-3, d alpha alpha alpha) at 8.5 MeV have been used to investigate the gamma decay of states in C-12. By measuring the four-body final state in complete kinematics we are able to detect gamma transitions indirectly. We find gamma transitions from the 15.11 MeV state in C-12 to the 12.71, 11.83, 10.3 and 7.65 MeV states followed by their breakup into three alpha particles. The relative gamma-ray branching ratios obtained are (1.2 +/- 0.3), (0.32 +/- 0.12), (1.4 +/- 0.2) and (4.4 +/- 0.8)%, respectively, with the remaining (92.7 +/- 1.0)% of the gamma decays going to the bound states. We obtain Gamma(alpha)/Gamma = (2.8 +/- 1.2)% for the isospinforbidden alpha decay of the 15.11 MeV state. From the 12.71 MeV state we find gamma transitions to the 10.3 and 7.65 MeV states. The relative gamma-ray branching ratios are (0.9(-0.5)(+0.6)) and (2.6(-1.2)(+1.6))%, respectively, with the remaining (96.6(-1.3)(+1.7))% of the gamma decays going to the bound states. Finally. we discuss the relation between the beta decay of N-12 and B-12 to states in C-12 and the gamma decay of the 15.11 MeV analog in C-12 to the same states. (C) 2009 Elsevier B.V. All rights reserved.
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| 4. |
- Nilsson, Maria, 1957-, et al.
(författare)
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Adolescent´s perceptions and expectations of parental action on children´s smoking and snus use : national cross sectional data from three decades
- 2009
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Ingår i: BMC Public Health. - : BioMed Central. - 1471-2458. ; 9:74
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Tidskriftsartikel (refereegranskat)abstract
- Background: Parents play a vital role as children develop tobacco behaviours. Many parents feel unsure about their possibility to influence their teenager's lifestyle. Knowledge about young people's acceptance for parental intervention could increase parental involvement. The overall objective of this study was to explore adolescents' perceptions and expectations of parental action regarding children's smoking and snus use, and whether they have changed over time. To see if there were differences whether the adolescent was a tobacco user or not the adolescents' tobacco use was followed; and described to put the findings on their perceptions and expectations of parental action in a context.Methods: The study used a repeated cross-sectional design, reporting Swedish national data from three decades. Data were collected in 1987, 1994 and 2003 by a questionnaire mailed to homes, in total to 13500 persons. The annual samples, which were random and national representative, consisted of 4500 young people aged 13, 15 and 17 yr, 1500 individuals per age group. The sampling and data collection procedures were done the same way during each survey. Chi2- tests were used to evaluate differences in distributions.Results: Adolescents in all age groups became more positive toward parental action over time. In 2003, more then 86% of the adolescents, including both smokers and non-smokers, strongly supported parental action on their children's smoking by trying to persuade them not to smoke (94%), by not smoking themselves (87%) and by not allowing their children to smoke at home (86%). Both non-smokers and smokers supported the idea of parental action in a similar way. Reduced pocket money had a weak support (42%), especially from girls. Eighty-nine percent of the adolescents expected their parents to act against smoking and 85% against snus use.Smoking was stable at 8% in 1987 and 1994 but decreased to 4% in 2003. In 1987 the snus use prevalence was 4% and in 2003 it was 3%. Snus users were mostly boys while few girls had done more than tried snus. More young people in all age groups had never tried smoking compared to the previous studies. In 2003 57% stated that they had never tried smoking.Conclusion: Adolescent smoking in Sweden has decreased and the proportion who never tried smoking has increased. The results of this study show that a growing majority of adolescents support strong parental intervention to help them refrain from tobacco, but preferably not in a punitive manner. This finding dismisses the notion that adolescents ignore or even disdain parental practices concerning tobacco. Prevention strategies and interventions addressing adolescent tobacco use that involve parents can be improved by using these findings to encourage parents to intervene against their children's tobacco use.
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| 5. |
- Nilsson, Maria, 1957-, et al.
(författare)
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“I would do anything for my child, even quit tobacco” : bonus effects from an intervention that target adolescent tobacco use
- 2009
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Ingår i: Scandinavian Journal of Psychology. - : John Wiley & Sons. - 0036-5564 .- 1467-9450. ; 50:4, s. 341-345
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Tidskriftsartikel (refereegranskat)abstract
- This paper aims to assess program bonus effects on adult tobacco use from a long term intervention that targeted adolescent tobacco use. The school-based community intervention started in Västerbotten County in Sweden in 1993 and adults were invited to support adolescents to stay tobacco-free. It was combined with repeated cross-sectional surveys in schools annually 1994-1999 among grades 7-9 and after 1999 every second year. Participating schools were randomly selected before the first survey representing both rural and urban settings. Out of 4,055 students, 1,008 (24.8%) reported that their supporting adult had been a tobacco user who quit tobacco in order to be allowed to participate. Out of these, 13.2% used tobacco daily before joining. The remaining 2,997 students’ adult partners were not tobacco users. Engaging tobacco using adults as partners in interventions targeting adolescent tobacco use seem to have a considerable tobacco-reducing bonus effect in the adults.
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| 6. |
- Nilsson, Maria, 1957-, et al.
(författare)
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It takes two: reducing adolescent smoking uptake through sustainable adolescent-adult partnership
- 2006
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Ingår i: Journal of Adolescent Health. - : Elsevier BV. - 1054-139X .- 1879-1972. ; 39:6, s. 880-886
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Tidskriftsartikel (refereegranskat)abstract
- Purpose To assess the effects of a long-term intervention for tobacco use prevention that targets adolescents (Tobacco Free Duo). Methods School-based community intervention combined with repeated cross-sectional surveys over 7 years. The intervention was performed in the County of Västerbotten, Sweden, where survey data were collected in grade seven to nine schools on an annual basis for 7 years. Data for comparison were collected in grade nine on the national level in Sweden. In the intervention area, the annual number of seventh to ninth grade students participating in the study varied between 1300 and 1650. In the reference data, the number of participating ninth grade students approximated 4500 annually. Results A significant decrease of nearly 50% was seen in smoking prevalence in the intervention area. The decrease was evident in grades eight and nine (ages 14–15 years) in both boys and girls. At the start of the intervention, smoking prevalence in grade nine was 16.1% in the intervention area and 23% in the national reference group. Although the prevalence in the national sample remained stable, there was a decrease to 9.0% in the intervention area at the end of the study period. Conclusions These results suggest that the Tobacco Free Duo program contributed to a reduction in adolescent smoking among both boys and girls. Using a multi-faceted intervention that includes adolescent–adult partnership can reduce adolescent smoking uptake, and the intervention has been proven to be sustainable within communities.
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| 7. |
- Nilsson, Maria, 1957-
(författare)
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Promoting health in adolescents : preventing the use of tobacco
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- There is a robust evidence base for the negative health effects from smoking. Smoking is linked to severe morbidity and to mortality, and kills up to half of its regular users. Tobacco use and production also bring other negative consequences such as economic loss for countries, poverty for individuals, child labour, deforestation and other environmental problems in tobacco growing countries. A combination of comprehensive interventions at different levels is needed to curb the tobacco epidemic. Tobacco control strategies at national levels in the western world often include components of information/education, taxation, legislative measures and influencing public opinion. Two approaches have dominated at the meso and micro levels: cessation support for tobacco users and prevention activities to support young people refraining from tobacco use. Smoking uptake is a complex process that includes factors at the societal level as well as social and individual characteristics. At national level, taxation and legislation can contribute to a societal norm opposing tobacco and creating a context for primary prevention aimed at tobacco free youth. There is no magic bullet in primary prevention. At the meso and micro levels, a continued development of knowledge on the underlying mechanisms and primary prevention methods is essential to prevent young people from starting to use tobacco. The overall aim of this thesis was to gain knowledge about factors that influence young people’s use of tobacco and of preventive mechanisms. The specific aims included to study the relation between Tobacco Free Duo, an intervention program targeting youth in Västerbotten County, and tobacco use prevalence. A specific interest was to explore the role adults can play in supporting young people to refrain from tobacco use. The thesis is based on four studies with three separate sets of data, two were quantitative and one was qualitative. The studies were conducted among adolescents (aged 13-15 yr) in Västerbotten County and on national level in Sweden (aged 13, 15 and 17 yr). Tobacco Free Duo is a school-based community intervention that started in 1993. An essential component of the intervention was to involve adults in supporting adolescents to stay tobacco free. Results showed decreased smoking in adolescents among both boys and girls in the intervention area during the study period of seven years. There was no change in a national reference group during the same time period. A bonus effect was a decrease in adult tobacco use in the intervention area. One out of four adults who supported a young person taking part in the intervention stopped using tobacco. In a qualitative assessment of young smokers, starting to smoke was described as a means of gaining control of their feelings and their situation during early adolescence. They expected adults to intervene against their smoking and claimed that close relations with caring adults could be a reason for smoking less or trying to quit smoking. In a quantitative study that used three decades of national data, over time adolescents became more positive toward parental action on children’s smoking. The adolescents strongly supported the idea of parental action, regardless of whether or not they themselves smoked. Adolescents preferred that actions from parents were dissuading their children from smoking, not smoking themselves, and not allowing their children to smoke at home. These results suggest that the Tobacco Free Duo program contributed to a reduction in adolescent smoking among both boys and girls. Using a multi-faceted intervention that includes an adolescent-adult partnership can decrease adolescent smoking uptake. Engaging adults as partners in tobacco prevention interventions that target adolescents has an important tobacco reducing bonus effect in the adults. The intervention has proven sustainable within communities. A growing majority of adolescents support parental interventions to help them refrain from tobacco. The findings dismiss the notion that adolescents ignore or even disdain parental practices concerning tobacco. A common and consequent norm against tobacco from both schools and parents using a supportive attitude can prevent tobacco use in young people.
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| 8. |
- Olsson, Mattias, 1975, et al.
(författare)
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Sorption of trivalent plutonium onto UO2 and the effect of the solid phase on the Pu oxidation state
- 2005
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Ingår i: Radiochimica Acta. ; 93, s. 341-346
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Tidskriftsartikel (refereegranskat)abstract
- A problem with plutonium in sorption studiesis its tendency to occur in a mix of oxidation states. Thiswork was a study of the sorption of plutonium on the solidphase UO2 in a perchlorate medium as a function of pH where plutonium is kept in its trivalent oxidation state.Experiments also showed that uranium(IV) oxide can reducePu(IV) to Pu(III) in an acidic solution and maintain it in thatstate. It was observed at the same time that the chemicallyinert solid phases TiO2 and ThO2 possibly increase the rateof disproportionation of Pu(IV) at a pH of about 0.5. Inaccordance with previous studies MnO2 was found to have anoxidizing effect, converting Pu(IV) into Pu(VI).A comparison is made between the sorption of Th(IV),Pu(III) and Co(II) on UO2 and TiO2, and Pu(VI) on TiO2.
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| 9. |
- Svane, Maria, 1957, et al.
(författare)
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On-Line Chemical Analysis of Individual Alkali-Containing Aerosol Particles by Surface Ionization Combined with Time-of-Flight Mass Spectrometry
- 2009
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Ingår i: Aerosol Science and Technology. - : Informa UK Limited. - 0278-6826 .- 1521-7388. ; 43:7, s. 653-661
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Tidskriftsartikel (refereegranskat)abstract
- An aerosol mass spectrometer for measurements of the alkali metal content in individual submicron aerosol particles is presented. The instrument combines surface ionization of individual particles on a hot platinum surface with orthogonal acceleration time-of-flight mass spectrometry. The instrument simultaneously provides the content of different alkali metal elements in single particles with high sensitivity. The instrument is characterized in laboratory experiments, and determination of the alkali metal content is demonstrated for particle diameters of 50-500 nm. The technique is demonstrated in ambient air measurements at an urban background site, and sea spray particles and particles originating from biomass burning are identified based on their content of sodium and potassium. Possible further improvements and applications of the technique are discussed.
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