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- Eriksson, E., et al.
(författare)
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Verocytotoxin-producing Escherichia coli 0157:H7 in the Swedish pig population
- 2003
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Ingår i: The Veterinary Record. - 0042-4900 .- 2042-7670. ; 152:23, s. 712-717
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Tidskriftsartikel (refereegranskat)abstract
- Verocytotoxin-producing Escherichia coli O157:H7 (VTEC O157:H7) was detected in two of 2446 individual faecal samples collected from pigs slaughtered at five Swedish slaughterhouses, indicating a prevalence of 0.08 per cent, with a 95 per cent confidence interval from 0 to 0-16 per cent. Four Swedish VTEC O157:H7-positive farms which kept ruminants and pigs were studied by repeated faecal sampling; VTEC O157:H7 was isolated from the ruminants and pigs on all the farms and the same strains were present in the pigs and the ruminants. On one of the farms, the organism persisted in the pig population for 11 months. On all four farms, management practices which might have influenced the isolation rate in pigs were identified. A group of young VTEC O157:H7-positive pigs was moved from one of the VTEC O157:H7-positive farms to a fattening herd where there were no ruminants. The number of VTEC O157:H7-positive faecal samples decreased gradually and after nine weeks the pigs were all negative; at slaughter none of the pigs was VTEC O157:H7-positive.
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| 4. |
- Na, A., et al.
(författare)
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Synthesis of phosphatidylcholine with (n-3) fatty acids by phospholipase A 2 in microemulsion
- 1990
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Ingår i: Journal of the American Oil Chemists Society. - 0003-021X .- 1558-9331. ; 67:11, s. 766-770
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Tidskriftsartikel (refereegranskat)abstract
- Phosphatidylcholine containing a long chain polyunsaturated acyl group at the 2-position has been prepared by phospholipase A 2 catalyzed esterification of lysophosphatidylcholine with polyunsaturated fatty acids EPA (C20:5) or DHA (C22:6). Preliminary studies showed that the other fatty acids, such as lauric acid (C12), palmitic acid (C16), stearic acid (C18) and linoleic acid (C18:2), were also incorporated. To our knowledge, phospholipase A 2 catalyzed condensation reactions have not been reported in the literature before. The reactions were performed in sodium bis(2-ethylhexyl)-sulfosuccinate-based microemulsions containing small amounts of water. Synthesis of the same phospholipid by transesterification of phosphatidylcholine with the polyunsaturated acids in microemulsion failed; however, enzymatic hydrolysis to lysophosphatidylcholine was facile, quantitative conversion from phosphatidylcholine being attained after 16 hr reaction time. An additional observation was that, unlike enzymatic hydrolysis of phospholipids, the condensation reaction catalyzed by phospholipase A 2 was totally independent of the presence of calcium. © 1990 AOCS Press.
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| 5. |
- Wittbom, C., et al.
(författare)
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Effect of solubility limitation on hygroscopic growth and cloud drop activation of SOA particles produced from traffic exhausts
- 2018
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Ingår i: Journal of Atmospheric Chemistry. - : Springer Science and Business Media LLC. - 0167-7764 .- 1573-0662. ; 75:4, s. 359-383
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Tidskriftsartikel (refereegranskat)abstract
- Hygroscopicity measurements of secondary organic aerosol (SOA) particles often show inconsistent results between the supersaturated and subsaturated regimes, with higher activity as cloud condensation nucleus (CCN) than indicated by hygroscopic growth. In this study, we have investigated the discrepancy between the two regimes in the Lund University (LU) smog chamber. Various anthropogenic SOA were produced from mixtures of different precursors: anthropogenic light aromatic precursors (toluene and m-xylene), exhaust from a diesel passenger vehicle spiked with the light aromatic precursors, and exhaust from two different gasoline-powered passenger vehicles. Three types of seed particles were used: soot aggregates from a diesel vehicle, soot aggregates from a flame soot generator and ammonium sulphate (AS) particles. The hygroscopicity of seed particles with condensed, photochemically produced, anthropogenic SOA was investigated with respect to critical supersaturation (sc) and hygroscopic growth factor (gf) at 90% relative humidity. The hygroscopicity parameter κ was calculated for the two regimes: κsc and κgf, from measurements of sc and gf, respectively. The two κ showed significant discrepancies, with a κgf /κsc ratio closest to one for the gasoline experiments with ammonium sulphate seed and lower for the soot seed experiments. Empirical observations of sc and gf were compared to theoretical predictions, using modified Köhler theory where water solubility limitations were taken into account. The results indicate that the inconsistency between measurements in the subsaturated and supersaturated regimes may be explained by part of the organic material in the particles produced from anthropogenic precursors having a limited solubility in water.
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| 9. |
- Bonnevier Wallstedt, Ida, et al.
(författare)
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Skin Anatomy, Bone Histology and Taphonomy of a Toarcian (Lower Jurassic) Ichthyosaur (Reptilia : Ichthyopterygia) from Luxembourg, with Implications for Paleobiology
- 2024
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Ingår i: Diversity. - : Multidisciplinary Digital Publishing Institute (MDPI). - 1424-2818. ; 16:8
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Tidskriftsartikel (refereegranskat)abstract
- A partial ichthyosaur skeleton from the Toarcian (Lower Jurassic) bituminous shales of the ‘Schistes Carton’ unit of southern Luxembourg is described and illustrated. In addition, associated remnant soft tissues are analyzed using a combination of imaging and molecular techniques. The fossil (MNHNL TV344) comprises scattered appendicular elements, together with a consecutive series of semi-articulated vertebrae surrounded by extensive soft-tissue remains. We conclude that TV344 represents a skeletally immature individual (possibly of the genus Stenopterygius) and that the soft parts primarily consist of fossilized skin, including the epidermis (with embedded melanophore pigment cells and melanosome organelles) and dermis. Ground sections of dorsal ribs display cortical microstructures reminiscent of lines of arrested growth (LAGs), providing an opportunity for a tentative age determination of the animal at the time of death (>3 years). It is further inferred that the exceptional preservation of TV344 was facilitated by seafloor dysoxia/anoxia with periodical intervals of oxygenation, which triggered phosphatization and the subsequent formation of a carbonate concretion.
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| 10. |
- Carlsson, CMG, et al.
(författare)
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Improved wettability of chemithermomechanical pulp by oxygen plasma treatment
- 1994
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Ingår i: Nordic Pulp & Paper Research Journal. - 0283-2631 .- 2000-0669. ; 9, s. 72-75,83
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Tidskriftsartikel (refereegranskat)abstract
- Chemithermomechanical pulp has been treated by cold plasma of oxygen, nitrogen, argon or air. The wettability increases as a result of treatment by oxygen or air plasmas but decreases when argon or nitrogen plasmas are used. The initial water absorption rate can be improved by more than 100 % using an oxygen plasma. After subsequent ageing of the pulp the improvement was ca 200 %. Electron Spectroscopy for Chemical Analysis (ESCA) shows that the oxygen plasma treatment increases the oxygen content of the fibre surfaces due to oxidation and/or removal of fatty acids, resin acids, and probably also lignin. The amount of extractable material increases after the plasma treatment, probably due to oxidation and scission of the lignin and the carbohydrates. This oxidized low molecular weight material may act as a surfactant decreasing the surface tension of the absorbing liquid and thus enhance the absorption rate.
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