| 1. |
- Ardö, Ylva, et al.
(författare)
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Studies of peptidolysis during early maturation and its influence on low-fat cheese quality
- 1989
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Ingår i: Milchwissenschaft. - 0026-3788. ; 44:8, s. 485-490
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Tidskriftsartikel (refereegranskat)abstract
- The effects of peptidolysis during early cheese ripening were studied in a low-fat (10% fat), round-eyed, semi-hard cheese using gel permeation chromatography and determinations of N content in cheese extracts. Addition of a heat-treated culture of Lactobacillus helveticus enhanced the peptidolytic activity even during the first weeks of cheese ripening. An aminopeptidase was found to have the necessary properties to cause the observed peptidolysis in the cheese after leakage from the cells. In the cheeses with heat-treated lactobacilli there were marked increases in cheese flavour intensity and an elimination of bitterness compared with control cheeses. The de-bittering effects due to high hydrolytic activities against peptides are discussed as well as effects of increased extracellular concn. of amino acids and/or small peptides on lactic acid bacteria metabolism. It is suggested that some stimulation of the fundamental functions of the starter bacteria might be necessary to achieve the desired flavour development in this type of low-fat cheese and that enhancement of peptidolysis during the very first weeks of cheese ripening is one method.
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| 2. |
- Bjornstad, T., et al.
(författare)
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Study of the Giant Gamow-Teller Resonance in Nuclear Beta-Decay - the Case of Ar-32
- 1985
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Ingår i: Nuclear Physics A. - : Elsevier BV. - 0375-9474. ; 443:2, s. 283-301
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Tidskriftsartikel (refereegranskat)abstract
- Delayed proton and gamma emissions following the β-decay of 32Ar have been studied. The half-life of 32Ar is 98 ± 2 ms, and the T = 2 analogue state in 32Cl lies at the excitation energy 5036 ± 12 keV. From the intensity of the feeding to this state the proton intensities can be converted to an absolute scale leading to a total proton branching ratio of (43 ± 3)%. From proton-gamma coincidence measurements it emerges that (1.9 ± 0.2)% of the protons lead to the first-excited state in 31S. A level scheme up to 8.75 MeV excitation in 32Cl has been constructed and the Gamow-Teller strength function has been deduced. The result is a renormalization of the axial-vector strength to (49 ± 5)% of the free-nucleon value.
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| 3. |
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| 4. |
- LARSSON, CUS, et al.
(författare)
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CORE-LEVEL SHIFTS ON THE H2O EXPOSED GE(100)2X1 SURFACE
- 1989
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Ingår i: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films. - : American Vacuum Society. - 0734-2101 .- 1520-8559. ; 7:3, s. 2044-2048
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Tidskriftsartikel (refereegranskat)
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| 5. |
- Larsson, N. P.O., et al.
(författare)
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Characterization of the response function of a Si(Li) detector using an absorber technique
- 1989
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Ingår i: Nuclear Inst. and Methods in Physics Research, B. - 0168-583X. ; 43:4, s. 574-580
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Tidskriftsartikel (refereegranskat)abstract
- The non-Gaussian response function of a Si(Li) detector has been measured for characteristic Kα X-rays in the energy interval 1.5-8.6 keV using an absorber technique. The method is based on the different response to an attenuating absorber placed in front of the detector for the detector tail as compared to fully absorbed photons in the same position in the spectrum. The shape of the tail of a Kα X-ray peak could be derived from three X-ray spectra acquired with different attenuating absorbers using the PIXE or XRF method for excitation of single element standards. The line shape function could be described by a full energy Gaussian, a shelf, an exponential and a Si-escape component. The results presented are in good agreement with previously reported response functions obtained in measurements of monochromatic X-rays. The results will be implemented in a computer program for evaluating micro-PIXE spectra.
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| 6. |
- Madsen, O. D., et al.
(författare)
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Cloned cell lines from a transplantable islet cell tumor are heterogeneous and express cholecystokinin in addition to islet hormones
- 1986
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Ingår i: Journal of Cell Biology. - : Rockefeller University Press. - 0021-9525 .- 1540-8140. ; 103:5, s. 2025-2034
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Tidskriftsartikel (refereegranskat)abstract
- A liver metastasis (MSL) with a remarkable in vitro proliferation potential has been identified in an NEDH rat carrying a transplantable x-ray-induced islet cell tumor. Two insulin-secreting cell lines, MSL-G and MSL-H, with doubling times of 3-5 d were established by repeated limiting dilution cloning. In vivo inoculation of MSL-G cells induced severe hypoglycemia caused by a small but highly heterogeneous tumor as revealed by immunocytochemistry. Whereas most cells stained for the islet hormones, insulin, glucagon, and somatostatin, clustered cells were discovered to contain cholecystokinin (CCK). Additional in vitro-limiting dilution cloning, followed by immunocytochemical characterization, clearly demonstrated the capacity of single cell clones to simultaneously express the same four hormones. Radioimmunoassays with a panel of site-specific antisera of culture supernatants and purified cell extracts showed the MSL-G2 cells to produce, store, and secrete readily detectable amounts of processed and unprocessed CCK. Gastrin was not detected while coexpression of glucagon and CCK were demonstrated. Mutant clones selected for resistance to 6-thioguanine (frequency, 2 x 10-7) and checked for HAT (hypoxanthine, aminopterin, thymidine) sensitivity retained the capacity for multihormone expression. We propose that the MSL tumor contains pluripotent endocrine stem cells. The MSL tumor and the MSL-G2 cells in particular will allow studies of not only CCK biosynthesis and processing but also of mechanisms involved in tumor and islet cell differentiation.
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| 7. |
- Ohlson, Sten, et al.
(författare)
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High Performance Liquid Affinity Chromatography: a New Tool in Biotechnology
- 1989
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Ingår i: Trends in Biotechnology. - : Elsevier BV. - 0167-7799 .- 1879-3096. ; 7:7, s. 179-186
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Tidskriftsartikel (refereegranskat)abstract
- In high performance liquid affinity chromatography (HPLAC), the biospecificity of affinity chromatography is combined with the robust support materials of HPLC. HPLAC can provide specificity, speed and high resolution in chromatography both on analytical and preparative scales. The number of commercially available HPLAC matrices is an indicator of the growing use of the technique.
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| 8. |
- Ohlson, Sten, et al.
(författare)
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High-Performance Liquid Affinity Chromatography: Rapid Immunoanalysis of Transferrin in Serum
- 1988
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Ingår i: Clinical Chemistry. - 0009-9147 .- 1530-8561. ; 34:10, s. 2039-2043
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Tidskriftsartikel (refereegranskat)abstract
- We describe a new method for quantitatively measuring substances ofclinical interest by high-performance liquid affinity chromatography(HPLAC). As a model system we selected analysis for transferrin in humanserum with immobilized antibodies in a high-performance liquidchromatographic system. SelectiSpher-10 Activated Tresyl columns (5 or 10 x0.5 cm) were used for in situ coupling of polyclonal antibodies totransferrin. The amount of transferrin eluted was determined by integratingthe eluted peak at 280 nm. The whole analytical procedure-- includinginjection of sample, washing, elution, and analysis of data-- takes only 7min. We characterized the HPLAC system for analysis of transferrin inseveral ways: intra-assay CV approximately 3%; inter- assay CV 2-9%; linearresponse up to 1 mg/mL column volume; detection limit approximately 3micrograms; analytical recovery 98% +/- 2%; purity of eluted sample greaterthan 95% (SDS-PAGE). The HPLAC method was compared with "rocket"immunoelectrophoresis, a commonly used method of analysis for transferrin,and there was excellent correlation between the two methods (r = 0.96, n =60). Benefits of this HPLAC technique include high precision, rapidanalysis, and simplified sample handling.
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| 9. |
- Starrin, Bengt, et al.
(författare)
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Arbetslöshet, lidande och död
- 1985
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Ingår i: Kritisk Psykologi 1985, 2, 18-29. ; 40, s. 18-29
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Tidskriftsartikel (refereegranskat)
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| 10. |
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