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| 2. |
- Nilsson, Lovisa, et al.
(författare)
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Relating the single particle soot photometer (SP2) signal response to soot maturity
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Ingår i: Aerosol Science and Technology. - 1521-7388.
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Tidskriftsartikel (refereegranskat)abstract
- Light absorbing carbonaceous aerosols produced from combustion span over a range of physicochemical properties. Soot is the most recognized species in this category and its formation process involves gradual maturation from amorphous young soot with a high hydrogen-to-carbon-ratio toward mature soot aggregates. In this work, the optical response of a single particle soot photometer (SP2) to electrical mobility size selected soot of different maturity produced by a mini-CAST soot generator is investigated. The results show that for soot of a specific mobility diameter, the laser-induced incandescence (LII) signal appears earlier and with a higher LII peak height for increasing soot maturity. The experimental observations are supported by simulations using a numerical model for the LII process. Furthermore, the effect of systematically varying the SP2 laser power on the detection of soot of different maturity using LII is explored. This work can be seen as a step toward the aim of using the SP2 instrument to identify soot particles of different maturity in the atmosphere.
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| 3. |
- Bergström, Stefan, et al.
(författare)
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Dual-headed Coincidence PET vs. Dedicated PET/CT in the Evaluation of Thoracic Malignancies
- 2010
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Ingår i: In Vivo. - 0258-851X .- 1791-7549. ; 24:2, s. 235-238
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to evaluate the usefulness of coincidence PET imaging as compared with dedicated PET/CT in cancer staging. Patients and Methods: Sixteen patients with thoracic malignancies referred to a PET/CT examination accepted to repeat the acquisition with a coincidence PET system. One experienced nuclear medicine physician compiled a report from the PET/CT examinations and the coincidence PET images. The reports were compared and evaluated according to the degree of agreement: no agreement, unsatisfactory, acceptable or satisfying agreement. Results: Satisfying or acceptable agreement between the PET/CT and the coincidence PET examination was found in 14 out of 16 patients (88%). The main issue for the examining physician was to anatomically locate the FDG uptake in the mediastinum in The coincidence PET images. Conclusion: The data from this small study imply that the staging results obtained with coincidence PET are in most cases concordant with those obtained with dedicated PET/CT.
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| 6. |
- Andersson, Stefan S., et al.
(författare)
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Mineral paragenesis and sulphide trace element distribution in the metamorphosed Lovisa Zn-Pb deposit, Bergslagen (Sweden), as revealed by 3D X-ray tomography, ore petrography and LA-ICP-MS analysis
- 2022
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Ingår i: Ore Geology Reviews. - : Elsevier BV. - 0169-1368 .- 1872-7360. ; 140
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Tidskriftsartikel (refereegranskat)abstract
- This study encompasses the ore mineralogy, textures and sulphide trace element chemistry of the Palaeoproterozoic Lovisa stratiform Zn-Pb deposit and the stratigraphically underlying Lovisa Fe Formation in the Bergslagen ore province (Sweden). We investigate the relative timing of formation and subsequent modifications of its ores in relation to the c. 1.87-1.80 Ga Svecokarelian orogeny. The Lovisa Zn-Pb deposit consists of several different ore types. The massive sphalerite-galena ore is distinctly deformed, exhibiting a multiple-scale "ball ore" texture with rounded silicate clasts within a deformed, fine-grained sulphide matrix. Underlying the massive ore is a locally folded, sphalerite-rich laminated ore, interpreted to represent a metamorphosed relict primary lamination. Several generations of sphalerite-galena fracture fillings and veins occur adjacent to the main ore zones and they cross-cut early ductile structures and metamorphic features. The trace element signatures of the sphalerite-galena infillings generally mimic those of the two main ore zones, thus supporting an origin by localised remobilisation of the primary sulphide ore and demonstrating limited trace element redistribution during this process. In contrast, discrete sulphosalt-rich fracture fillings cross-cutting earlier galena-chalcopyriterich fracture fillings and veinlets in the Lovisa Fe Formation suggest a significant but still relatively localised redistribution of metals. Trace element mapping of sulphides from the Lovisa Zn-Pb deposit reveals that inclusion-free overgrowths on pyrite crystals are locally Co-enriched compared to the cores, which resulted from the redistribution of Co during late metamorphic processes. Combined textural and geochemical evidence suggest that the originally syngenetic exhalative sulphide ore at Lovisa was locally strongly affected by polyphase deformation and remobilisation. This was initiated during the first stage of amphibolite facies grade regional metamorphism and deformation (D1, c. 1.87-1.85 Ga) but is mostly evident from the later stages (D2) and the evolution to retrograde and brittle conditions (c. 1.83-1.80 Ga and later).
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| 8. |
- Axenrot, Thomas; Bergqvist, Björn; Carlstein, Mikael; Degerman, Erik,
(författare)
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Fiskundersökningar i större vattendrag
- 2007
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- De större vattendragen (åar, älvar och floder) är ofta bristfälligtundersökta, trots att de ofta är kraftigt påverkade av mänskligaaktiviteter. Under senare år har behovet av undersökningari dessa vattendrag ökat eftersom EU:s ramdirektiv för vattenkräver övervakning av vattnens ekologiska status i alla typer avvatten. Det har också under senare förts fram önskemål om attkunna använda metoder som inte är destruktiva (dödande) vidkvantifi ering av fi skförekomsten i både sjöar och vattendrag.I syfte att utveckla icke dödande metoder för kvantitativafi skundersökningar i större vattendrag har under åren 2005och 2006 ett pilotprojekt omfattande både båtelfi ske ochhydroakustiska metoder (mobil horisontell ekolodning)genomförts i vattendragen Österdalälven (Älvdalens kommun)och Svartån (Örebro kommun). Projektet har genomförts som ettsamarbetsprojekt mellan Fiskeriverkets sötvattenslaboratorium,Systemekologiska institutionen vid Stockholms Universitet ochF.A.S.T. – Fiskeresursgruppen vid Älvdalens utbildningscentrum.Projektet har genomförts som ett utvecklingsprojekt inommiljöövervakningsprogrammet och har fi nansierats avNaturvårdsverkets Miljöövervakningsenhet.Arbetet har genomförts med målsättningen att metodiken skallvara tillämpbar för såväl övervakning av fi skresurserna somför miljöövervakning och bedömning av ekologisk status enligtramdirektivets krav. Dessutom skall metodiken kunna användasför uppföljning av de nationella miljökvalitetsmålen. Villkorsom måste uppfyllas är att metoderna skall ge informationom fi skbeståndens sammansättning, individtäthet ochstorleksfördelning utan att fi sken behöver dödas.I denna rapport redovisas resultatet av undersökningarna ochen jämförelse av de båda testade metoderna (båtelfi ske ochekolodning), dessutom ges rekommendationer för framtidaundersökningar i större vattendrag. Avsikten är att rapporten skallutgöra plattform för arbetet med att ta fram en standardiseradmetodik för undersökningar i större vattendrag som inte ärvadbara.
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| 9. |
- Bergqvist, Anders, et al.
(författare)
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The Hepatitis C Virus Core Protein Modulates T Cell Responses by Inducing Spontaneous and Altering T-cell Receptor-triggered Ca2+ Oscillations
- 2003
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Ingår i: Journal of Biological Chemistry. - : ASBMB. - 0021-9258 .- 1083-351X. ; 278:21, s. 18877-18883
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Tidskriftsartikel (refereegranskat)abstract
- Alterations of cytokine responses are thought to favor the establishment of persistent hepatitis C virus (HCV) infection, enhancing the risk of liver cirrhosis and hepatocellular carcinoma. Expression of the HCV core (C) protein modulates transcription of the IL-2 promoter in T lymphocytes by activating the nuclear factor of activated T lymphocyte (NFAT) pathway. Here we report on the effect of HCV C on Ca2+ signaling, which is essential for activation of NFAT. Expression of HCV C correlated with increased levels of cytosolic Ca2+ and spontaneous Ca2+ oscillations in transfected Jurkat cells. Triggering of the T-cell receptor induced a prolonged Ca2+ response characterized by vigorous high frequent oscillations in a high proportion of the responding cells. This was associated with decreased sizes and accelerated emptying of the intracellular calcium stores. The effect of HCV C on calcium mobilization was not dependent on phospholipase C-1 (PLC-) activity or increased inositol 1,4,5-trisphosphate (IP3) production and did not require functional IP3 receptors, suggesting that insertion of the viral protein in the endoplasmic reticulum membrane may be sufficient to promote Ca2+ leakage with dramatic downstream consequences on the magnitude and duration of the response. Our data suggest that expression of HCV C in infected T lymphocytes may contribute to the establishment of persistent infections by inducing Ca2+ oscillations that regulate both the efficacy and information content of Ca2+ signals and are ultimately responsible for induction of gene expression and functional differentiation.
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