| 21. |
- Andreasson, Björn Pererik, 1979-, et al.
(författare)
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Spatial distribution of oxygen vacancies in Cr-doped SrTiO3 during an electric-field-driven insulator-to-metal transition
- 2009
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Ingår i: Applied Physics Letters. - College Park, MD : American Institute of Physics (AIP). - 0003-6951 .- 1077-3118. ; 94:1, s. Article number: 013513-
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Tidskriftsartikel (refereegranskat)abstract
- Spatially resolved x-ray fluorescence maps are presented that show the introduction and the evolution of oxygen vacancies in chromium-doped strontium titanate during an electric-field-driven insulator-to-metal transition. The vacancies are introduced at the anode and diffuse through the crystal toward the cathode. The spatial distribution of vacancies is explained by a model describing the electrical breakdown as a percolation process. Strong differences in the vacancy distribution were found when the transition took place in air and in a hydrogen-enriched atmosphere. In air, the vacancies disappeared from the surface, whereas in the reducing hydrogen atmosphere, they remained at the surface. © 2009 American Institute of Physics.
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| 22. |
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| 23. |
- Andréasson, Karin, et al.
(författare)
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Body mass index in adolescence, risk of type 2 diabetes and associated complications: A nationwide cohort study of men
- 2022
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Ingår i: EClinicalMedicine. - : Elsevier BV. - 2589-5370. ; 46
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Tidskriftsartikel (refereegranskat)abstract
- Background Obesity is a predominant factor in development of type 2 diabetes but to which extent adolescent obesity influences adult diabetes is unclear. We investigated the association between body mass index (BMI) in young men and subsequent type 2 diabetes and how, in diagnosed diabetes, adolescent BMI relates to glycemic control and diabetes complications. Methods Baseline data from the Swedish Conscript Register for men drafted 1968-2005 was combined with data from the National Diabetes and Patient registries. Diabetes risk was estimated through Cox regression and Kaplan-Meier survival estimates. Relationships between BMI, glycemic control and diabetes complications were assessed through multiple linear and logistic regression. Findings Among 1,647,826 men, 63,957 (3.88%) developed type 2 diabetes over a median follow-up of 29.0 years (IQR[21.0-37.0]). The risk of diabetes within 40 years after conscription was nearly 40% in individuals with adolescent BMI >= 35 kg/m(2). Compared to BMI 18.5-<20 kg/m(2) (reference), diabetes risk increased in a linear fashion from HR 1.18(95%CI 1.15-1.21) for BMI 20-<22.5 kg/m(2) to HR 15.93(95%CI 14.88-17.05) for BMI >= 35 kg/m(2), and a difference in age at onset of 11.4 years was seen. Among men who developed diabetes, higher adolescent BMI was associated with higher HbA1c levels and albuminuria rates. Interpretation Rising adolescent BMI was associated with increased risk of type 2 diabetes diagnosed at a younger age, with poorer metabolic control, and a greater prevalence of albuminuria, all suggestive of worse prognosis. Copyright (C) 2022 The Authors. Published by Elsevier Ltd.
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| 24. |
- Andreasson, Kristin I. M., 1963, et al.
(författare)
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Biological weighting functions as a tool for evaluating two ways to measure UVB radiation inhibition on photosynthesis
- 2006
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Ingår i: Journal of Photochemistry and Photobiology B-Biology. - : Elsevier BV. - 1011-1344. ; 84:2, s. 111-118
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Tidskriftsartikel (refereegranskat)abstract
- To estimate the inhibitory effect of the changing UVB radiation (UVBR, 280-315 nm) on earth's ecosystems, an understanding of its wavelength dependency is needed. The tool used for these estimations is the biological weighting function (BWF), whereby the inhibition of different wavelengths is calculated. B\WFs were determined for three algae species from different classes, Phaeodactylum tricornutum (Bacillariophyceae), Dunaliella tertiolecta (Chlorophyceae) and Rhodomonas sp. (Cryptophyceae), using polychromatic irradiation, where the UVBR spectra were varied with cut-off filters. For each alga, BWFs were determined for two photosynthetic parameters; the quantum yield measured as fluorescence from Photo System II in a pulse-amplitude-modulation (PAM) fluorometer, and the fixation of C-14-labelled carbon dioxide. The BWFs were calculated with the Rundel method, using the radiation data between 270 and 360 nm with 1 nm resolution. The results show that the UVBR damages were generally higher when using the carbon fixation measurements than when measuring with the PAM technique. When using PAM, P. tricornutum in particular had a sensitivity intermediate between the sensitive Rhodomonas sp. and the more tolerant D. tertiolecta, but was as sensitive as, or even more sensitive, than Rhodomonas sp. when using carbon fixation. D. tertiolecta was shown to be less sensitive when using both techniques and the inhibition of its photosynthesis was almost as high when using PAM as when using carbon fixation. We concluded that, although the PAM technique has advantages such as being cleaner and easier to use, it is unable to Substitute the carbon fixation measurements. Not only are the algae less sensitive when measured with PAM than they are when measured as carbon fixation, the relationship between the effects on the algae measured with the two techniques also differs. As fixation of carbon dioxide integrates a larger part of the photosynthetic machinery, it should be favoured as a measure of photosynthesis. (c) 2006 Elsevier B.V. All rights reserved.
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| 25. |
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| 26. |
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| 27. |
- Andreasson, Kristin I. M., 1963, et al.
(författare)
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Reduction in growth rate in Phaeodactylum tricornutum (Bacillarlophyceae) and Dunaliella tertiolecta (Chlorophyceae) induced by UV-B radiation
- 2007
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Ingår i: Journal of Photochemistry and Photobiology B-Biology. - : Elsevier BV. - 1011-1344. ; 86:3, s. 227-233
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Tidskriftsartikel (refereegranskat)abstract
- The effect of UV-B radiation (UVBR, 280-315 nm) on growth rate during 72 h of incubation, was measured for two marine microalgae - Dunaliella tertiolecta (Chlorophyceae) and Phaeodactyhan tricornutum (Bacillariophyceae). The resulting inhibition of growth rate was analysed by calculating biological weighting functions (BWFs). The growth rate of D. tertiolecta was slightly more inhibited by UVBR (over the whole range of the spectrum) than was the growth rate of P. tricornutum, but the wavelength dependencies were the same. Our results were compared with results from photosynthesis experiments of Andreasson and Wangberg [1], where two methods, pulse amplitude modulation (PAM) fluorescence and carbon fixation, were measured for these same algae. The BWF for the growth rate, here, showed more wavelength dependency than the BWF for the previous two photosynthesis measurements - except for the carbon fixation BWF in P. tricornutum, which was closer to the BWF for growth rate. The wavelength dependency of the growth rate inhibition showed less variation between the species than the inhibition of the photosynthesis. (c) 2006 Elsevier B.V. All rights reserved.
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| 28. |
- Andreasson, K. I., et al.
(författare)
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Targeting innate immunity for neurodegenerative disorders of the central nervous system
- 2016
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Ingår i: Journal of Neurochemistry. - : Wiley. - 0022-3042. ; , s. 653-693
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Tidskriftsartikel (refereegranskat)abstract
- Neuroinflammation is critically involved in numerous neurodegenerative diseases, and key signaling steps of innate immune activation hence represent promising therapeutic targets. This mini review series originated from the 4th Venusberg Meeting on Neuroinflammation held in Bonn, Germany, 7–9th May 2015, presenting updates on innate immunity in acute brain injury and chronic neurodegenerative disorders, such as traumatic brain injury and Alzheimer disease, on the role of astrocytes and microglia, as well as technical developments that may help elucidate neuroinflammatory mechanisms and establish clinical relevance. In this meeting report, a brief overview of physiological and pathological microglia morphology is followed by a synopsis on PGE2 receptors, insights into the role of arginine metabolism and further relevant aspects of neuroinflammation in various clinical settings, and concluded by a presentation of technical challenges and solutions when working with microglia and astrocyte cultures. Microglial ontogeny and induced pluripotent stem cell-derived microglia, advances of TREM2 signaling, and the cytokine paradox in Alzheimer's disease are further contributions to this article. (Figure presented.) Neuroinflammation is critically involved in numerous neurodegenerative diseases, and key signaling steps of innate immune activation hence represent promising therapeutic targets. This mini review series originated from the 4th Venusberg Meeting on Neuroinflammation held in Bonn, Germany, 7–9th May 2015, presenting updates on innate immunity in acute brain injury and chronic neurodegenerative disorders, such as traumatic brain injury and Alzheimer's disease, on the role of astrocytes and microglia, as well as technical developments that may help elucidate neuroinflammatory mechanisms and establish clinical relevance. In this meeting report, a brief overview on physiological and pathological microglia morphology is followed by a synopsis on PGE2 receptors, insights into the role of arginine metabolism and further relevant aspects of neuroinflammation in various clinical settings, and concluded by a presentation of technical challenges and solutions when working with microglia cultures. Microglial ontogeny and induced pluripotent stem cell-derived microglia, advances of TREM2 signaling, and the cytokine paradox in Alzheimer's disease are further contributions to this article. © 2016 International Society for Neurochemistry
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| 30. |
- Andreasson, Ulf, 1968, et al.
(författare)
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Commutability of the certified reference materials for the standardization of beta-amyloid 1-42 assay in human cerebrospinal fluid: lessons for tau and beta-amyloid 1-40 measurements
- 2018
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Ingår i: Clinical Chemistry and Laboratory Medicine. - : Walter de Gruyter GmbH. - 1434-6621 .- 1437-4331. ; 56:12, s. 2058-2066
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Tidskriftsartikel (refereegranskat)abstract
- Background: The core Alzheimer's disease cerebrospinal fluid (CSF) biomarkers total tau (T-tau), phosphorylated tau (P-tau), beta-amyloid 1-42 (A beta 42) and beta-amyloid 1-40 (A beta 40) are increasing in importance and are now part of the research criteria for the diagnosis of the disease. The main aim of this study is to evaluate whether a set of certified reference materials (CRMs) are commutable for A beta 42 and to serve as a feasibility study for the other markers. This property is a prerequisite for the establishment of CRMs which will then be used by manufacturers to calibrate their assays against. Once the preanalytical factors have been standardized and proper selection criteria are available for subject cohorts this harmonization between methods will allow for universal cut-offs to be determined. Methods: Thirty-four individual CSF samples and three different CRMs where analyzed for T-tau, P-tau, A beta 42 and A beta 40, using up to seven different commercially available methods. For A beta 40 and A beta 42 a mass spectrometry-based procedure was also employed. Results: There were strong pairwise correlations between the different methods (Spearman's p>0.92) for all investigated analytes and the CRMs were not distinguishable from the individual samples. Conclusions: This study shows that the CRMs are commutable for the different assays for A beta 42. For the other analytes the results show that it would be feasible to also produce CRMs for these. However, additional studies are needed as the concentration interval for the CRMs were selected based on A beta 42 concentrations only and did in general not cover satisfactory large concentration intervals for the other analytes.
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