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- Grange, Kristina, 1970
(författare)
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Kulturkrock eller brobygge?
- 1998
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Ingår i: Arkitektidningen. ; :10, s. 10-11:4, s. 16-18
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 2. |
- Undeland, Ingrid, 1968, et al.
(författare)
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Comparison between methods using low-toxicity solvents for the extraction of lipids from herring (Clupea harengus)
- 1998
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Ingår i: Food Chemistry. - 0308-8146 .- 1873-7072 .- 0346-718X. ; 61:3, s. 355-365
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Tidskriftsartikel (refereegranskat)abstract
- Three alkane/alcohol/water-based lipid extraction systems were evaluated to determine which would be the best replacement for the frequently used chloroform/methanol/water system, nowadays known to be very toxic. All the methods were applied to samples of minced herring (Clupea harengus) differing in quality and composition. In addition to comparisons of total lipid yield, the extracted lipids were compared with respect to content of triglycerides, phospholipids, free fatty acids, ?-tocopherol, lipid hydroperoxides and conjugated dienes. The content of phospholipids was found to differ most between the lipids extracted by the four methods. Here, the chloroform/methanol/water system was the most efficient, followed by heptane/ethanol/water/sodium dodecyl sulphate (SDS) and then iso-propanol/hexane. However, by decreasing the level of SDS, the efficiency of the heptane/ethanol/water/SDS system in extracting phospholipids was increased to the same level as that of the chloroform/methanol/water system. This decrease in SDS also resulted in a higher recovery of free fatty acids. The lack of correlation between yields of phospholipids and yields of lipid oxidation products throughout this study was surprising because of the often-described susceptibility of phospholipids to oxidation.
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| 6. |
- Undeland, Ingrid, 1968, et al.
(författare)
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Lipid Oxidation in Minced Herring (Clupea harengus) during Frozen Storage. Effect of Washing and Precooking
- 1998
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Ingår i: Journal of Agricultural and Food Chemistry. - 0021-8561 .- 1520-5118. ; 46, s. 2319-2328
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Tidskriftsartikel (refereegranskat)abstract
- A 23 factorial experimental design was used to investigate the effect of washing in combination with precooking on the oxidative stability of lipids in minced herring (Clupea harengus) at −18 °C. The following variables were studied: washing (no, yes), cooking time (38, 54 min), and cooking temperature (55, 100 °C).The responses monitored were peroxide value (PV), absorbance at 234 nm (A234), absorbance at 268 nm (A268), and lipid soluble fluorescent products (FP). A partial least-squares regression analysis (PLS) revealed that the best lipid stability was obtained at minimum cooking time and at lower temperature. On the basis of compositional analyses and in vitro experiments, this finding was proposed to be due to heat inactivation of catalytic enzymes, without simultaneous activation, for example, of hemoproteins. Washing reduced these benefits from precooking by removal of pro-oxidative enzymes and also through a reduction in the amount of antioxidants as well as a relative increase in phospholipids and free fatty acids in the fat.
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| 8. |
- Pradhan, P., et al.
(författare)
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Induced Circular Dichroism of Benzo(a)pyrene-7,8-dihydrodiol 9,10-Epoxide Stereoisomers Covalently Bound to Deoxyribooligonucleotides Used to Probe Equilibrium Distribution between Groove Binding and Intercalative Adduct Conformations
- 1998
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Ingår i: Biochemistry. - : American Chemical Society (ACS). - 1520-4995 .- 0006-2960. ; 37:13, s. 4664-4673
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Tidskriftsartikel (refereegranskat)abstract
- Binding conformations of single anti-BPDE-N-2-dG adducts in oligonucleotides of varying base composition have been studied by induced circular dichroism (ICD). The sign of the ICD around 350 nm of single-stranded oligonucleotide adducts and the sign of an exciton type of CD component at 260 nm in both single strand and duplex farms of adducts correlate with the absolute configuration of the cyclohexyl moiety of the adduct. Changes in magnitude and sign of the ICD around 350 nm were observed upon duplex formation. The results show that adducts displaying external (minor groove) binding characteristics are associated with a significant positive ICD. Conversely, adducts displaying intercalation binding characteristics were found to have a positive or negative ICD. The magnitude of the ICD is dependent on the sequence context and the particular adduct isomer studied. Duplexes with (+)-trans-anti-BPDE-N-2-dG in 5'-d(CCTATCGCTATCC) or 5'-d(CCTATAGATATCC) exhibit a relatively strong positive ICD. In contrast, the duplexes with (+)-trans-anti-BPDE-N-2-dG in 5'-d(CCTATTGCTATCC) and 5'-d(CCTATTGTTATCC) display a small positive and negative ICD, respectively, in both cases suggesting conformational heterogeneity. Partially complementary duplexes (dA, dT, or do) localized opposite the (+)-trans-anti-BPDE-N-2-dG adduct in 5'-d(CCTATCGCTATCC) or 5'-d(CCTATAGATATCC) also demonstrated negative ICD. These results together with light absorption characteristics suggest a preferred conformation of intercalation for the mismatched duplexes. Evidence of an equilibrium between the external and intercalative adduct conformation is provided by the results from the temperature dependence of the near-UV absorption and ICD characteristics of (+)-trans-anti-BPDE-N-2-dG complex in a 5'-d(CCTATAGATATCC) duplex.
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| 9. |
- Sehlstedt, U., et al.
(författare)
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Interactions of the Antiviral Quinoxaline Derivative 9-OH-B220 {2,3-dimethyl-6-(dimethylaminoethyl)-9-hydroxy-6H-indolo-[2,3-b] quinoxaline} with Duplex and Triplex forms of Synthetic DNA and RNA
- 1998
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Ingår i: Journal of Molecular Biology. - : Elsevier BV. - 0022-2836 .- 1089-8638. ; 278:1, s. 31-56
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Tidskriftsartikel (refereegranskat)abstract
- The binding of an antiviral quinoxaline derivative, 2,3-dimethyl-6-(dimethylaminoethyl)-9 -hydroxy-6H-indolo-[2,3-b]quinoxaline (9-OH-B220), to synthetic double and triple helical DNA (poly(dA).poly(dT) and poly(dA.)2poly(dT)) and RNA (poly(rA).poly(rU) and poly(rA) .2poly(rU)) has been characterized using flow linear dichroism (LD), circular dichroism (CD), fluorescence spectroscopy, and thermal denaturation. When either of the DNA structures or the RNA duplex serve as host polymers a strongly negative LD is displayed, consistent with intercalation of the chromophoric ring system between the base-pairs/triplets of the nucleic acid structures. Evidence for this geometry also includes weak induced CD signals and strong increments of the fluorescence emission intensities upon binding of the drug to each of these polymer structures. Ln agreement with intercalative binding, 9-OH-B220 is found to effectively enhance the thermal stability of both the double and triple helical states of DNA as well as the RNA duplex. Ln the case of poly(dA).2poly(dT), the drug provides an unusually large stabilization of its triple helical state; upon binding of 9-OH-B220 the tripler-to-duplex equilibrium is shifted towards higher temperature by 52.5 deg. C in a 10 mM sodium cacodylate buffer (pH 7.0) containing 100 mM NaCl and 1 mM EDTA.When triplex RNA serves as host structure, LD indicates that the average orientation angle between the drug chromophore plane and the helix axis of the triple helical RNA is only about 60 to 65 degrees. Moreover, the thermal stabilizing capability, as well as the fluorescence increment, CD inducing power and perturbations of the absorption envelope, of 9-OH-B220 in complex with the RNA tripler are all less pronounced than those observed for the complexes with DNA and duplex RNA. These features indicate binding of 9-OH-B220 in the wide and shallow minor groove of poly(rA).2poly(rU).Based on the present results, some implications for the applications of this low-toxic, antiviral and easily administered drug in an antigene strategy, as well as its potential use as an antiretroviral agent, are discussed
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| 10. |
- Wassenius, Ola, et al.
(författare)
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Variability in Skin Exposure in Machine Operators Exposed to Cutting Fluids
- 1998
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Ingår i: Scandinavian Journal of Work, Environment and Health. - : Scandinavian Journal of Work, Environment and Health. - 0355-3140 .- 1795-990X. ; 24:2, s. 125 - 129
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Tidskriftsartikel (refereegranskat)abstract
- Objective. This study describes a new technique for measuring skin exposure to cutting fluids and evaluates the variability of skin exposure among machine operators performing cyclic (repetitive) work. Methods. The technique is based on video recording and subsequent analysis of the videotape by means of computer-synchronized video equipment. The time intervals at which the machine operator's hand was exposed to fluid were registered, and the total wet time of the skin was calculated by assuming different evaporation times for the fluid. The exposure of twelve operators with different work methods was analyzed in six different workshops, which included a range of machine types, from highly automated metal cutting machines (ie, actual cutting and chip removal machines) requiring operator supervision to conventional metal cutting machines, where the operator was required to maneuver the machine and manually exchange products. Results; the relative wet time varied between 0% and 100%. A significant association between short cycle time and high relative wet time was noted. However, there was no relationship between the degree of automatization of the metal cutting machines and wet time. Conclusions. The study shows that skin exposure to cutting fluids can vary considerably between machine operators involved in manufacturing processes using different types of metal cutting machines. The machine type was not associated with dermal wetness. The technique appears to give objective information about dermal wetness. A comment: This publication is a result of a cooperation between the authors at Chalmers University of Technology and Gothenburg University, i.e. between the Department of Transportation and the Department of Occupational Health and the Department of Sociology.
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