| 1. |
- Ademark, Pia, et al.
(författare)
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Hydrolytic properties of a beta-mannosidase purified from Aspergillus niger. J. Biotechnol. 75: 281-289.
- 1999
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Ingår i: Journal of Biotechnology. - 1873-4863. ; 75:2-3, s. 281-289
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Tidskriftsartikel (refereegranskat)abstract
- A β-mannosidase was purified to homogeneity from the culture filtrate of Aspergillus niger. A specific activity of 500 nkat mg−1 and a 53-fold purification was achieved using ammonium sulfate precipitation, anion-exchange chromatography, and gel filtration. The isolated enzyme has an isoelectric point of 5.0 and appears to be a dimer composed of two 135-kDa subunits. It is a glycoprotein and contains 17% N-linked carbohydrate by weight. Maximal activity was observed at pH 2.4–5.0 and at 70°C. The β-mannosidase hydrolyzed β-1,4-linked manno-oligosaccharides of degree of polymerization (DP) 2–6 and also released mannose from polymeric ivory nut mannan and galactomannan. The Km and Vmax values for p-nitrophenyl-β-Image-mannopyranoside were 0.30 mM and 500 nkat mg−1, respectively. Hydrolysis of Image-galactose substituted manno-oligosaccharides showed that the β-mannosidase was able to cleave up to, but not beyond, a side group. An internal peptide sequence of 15 amino acids was highly similar to that of an Aspergillus aculeatus β-mannosidase belonging to family 2 of glycosyl hydrolases.
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| 2. |
- Klarbring, Anders, et al.
(författare)
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Theory of Residual Stresses with Application to an Arterial Geometry
- 2007
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Ingår i: Archives of Mechanics. - 0373-2029. ; 59:4-5, s. 341-364
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a theory of residual stresses, with applications to biomechanics, especially to arteries. For a hyperelastic material, we use an initial local deformation tensor K as a descriptor of residual strain. This tensor, in general, is not the gradient of a global deformation, and a stress-free reference configuration, denoted B¯, therefore, becomes incompatible. Any compatible reference configuration B0 will, in general, be residually stressed. However, when a certain curvature tensor vanishes, there actually exists a compatible and stress-free configuration, and we show that the traditional treatment of residual stresses in arteries, using the opening–angle method, relates to such a situation. Boundary value problems of nonlinear elasticity are preferably formulated on a fixed integration domain. For residually stressed bodies, three such formulations naturally appear: (i) a formulation relating to B0 with a non-Euclidean metric structure; (ii) a formulation relating to B0 with a Euclidean metric structure; and (iii) a formulation relating to the incompatible configuration B¯. We state these formulations, show that (i) and (ii) coincide in the incompressible case, and that an extra term appears in a formulation on B¯, due to the incompatibility.
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| 3. |
- Yang, YP, et al.
(författare)
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Hospital-Treated Infections and Increased Risk of Two EBV-Related Malignancies: A Nested Case-Control Study
- 2022
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Ingår i: Cancers. - : MDPI AG. - 2072-6694. ; 14:15
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Tidskriftsartikel (refereegranskat)abstract
- Background: To assess the association of hospital-treated infections with the subsequent risk of two Epstein-Barr virus (EBV)-related malignancies, namely Hodgkin’s lymphoma (HL) and nasopharyngeal carcinoma (NPC). Methods: We performed a nested case-control study based on several national registers in Sweden. Cases were individuals newly diagnosed with HL or NPC during 1994–2016 in Sweden, according to the Swedish Cancer Register. For each case, we randomly selected five controls individually matched to the case on sex and year of birth from the general Swedish population. Hospital-treated infections (i.e., infections requiring either inpatient or outpatient hospital care) were identified from the Swedish Patient Register. Conditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) of HL and NPC, in relation to hospital-treated infections, after adjustment for age, sex, calendar period, educational achievement, and region of residence. Results: The study included a total of 890 cases of HL and 306 cases of NPC. A hospital-treated infection three years ago or earlier was associated with a higher risk of HL (OR = 1.49, 95%CI: 1.26–1.75) as well as NPC (OR = 1.36; 95%CI: 1.01–1.83). The positive association was noted for both bacterial and viral infections and primarily for respiratory and skin infections. A monotonous dose-response relationship was found between a number of hospital-treated infections and the risk of HL (p = 0.02) but less compelling for NPC (p = 0.06). Using a 5-year lag time rendered similar results (OR = 1.43, 95%CI: 1.21–1.70 for HL; OR = 1.43, 95%CI: 1.05–1.95 for NPC). Conclusions: These findings suggest that infections requiring hospital treatment might contribute to the carcinogenesis of malignancies potentially related to EBV.
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