| 61. |
- Axelsson, Anders, et al.
(författare)
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Simulation of batch and continuous reactors with co-immobilized yeast and β-galactosidase
- 1991
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Ingår i: Journal of Chemical Technology and Biotechnology. - : Wiley. - 0268-2575 .- 1097-4660. ; 52:4, s. 481-497
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Tidskriftsartikel (refereegranskat)abstract
- A reaction-diffusion model was used to simulate a co-immobilized system utilizing the numerical method of orthogonal collocation. The production of ethanol from deproteinized whey using beta-galactosidase co-immobilized with Saccharomyces cerevisiae in calcium alginate gel beads was chosen as a model system. Calculated concentrations of lactose, glucose, galactose and ethanol were compared with experimental data for a batch reactor and a continuous horizontal packed-bed reactor. The mathematical model has been used to analyse the influence of internal and external mass transfer for the continuous reactor. The external mass transfer was shown to be of minor importance. The introduction of baffles decreased the backmixing in the horizontal packed-bed reactor. Internal mass transfer was found to be the main cause of the reduction in the apparent reaction rate. Thus, much of the expected increase in reaction rate is diminished by mass transfer hindrance when the cell concentration is increased.
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| 62. |
- Axelsson, Annika, et al.
(författare)
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Sox5 regulates beta-cell phenotype and is reduced in type 2 diabetes
- 2017
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Type 2 diabetes (T2D) is characterized by insulin resistance and impaired insulin secretion, but the mechanisms underlying insulin secretion failure are not completely understood. Here, we show that a set of co-expressed genes, which is enriched for genes with islet-selective open chromatin, is associated with T2D. These genes are perturbed in T2D and have a similar expression pattern to that of dedifferentiated islets. We identify Sox5 as a regulator of the module. Sox5 knockdown induces gene expression changes similar to those observed in T2D and diabetic animals and has profound effects on insulin secretion, including reduced depolarization-evoked Ca 2+-influx and β-cell exocytosis. SOX5 overexpression reverses the expression perturbations observed in a mouse model of T2D, increases the expression of key β-cell genes and improves glucose-stimulated insulin secretion in human islets from donors with T2D. We suggest that human islets in T2D display changes reminiscent of dedifferentiation and highlight SOX5 as a regulator of β-cell phenotype and function.
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| 63. |
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| 64. |
- Axelsson, Anders, et al.
(författare)
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The use of holographic interferometry and electron speckle pattern interferometry for diffusion measurement in biochemical and pharmaceutical engineering applications
- 2008
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Ingår i: Optics and Lasers in Engineering. - : Elsevier BV. - 0143-8166. ; 46:12, s. 865-876
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Tidskriftsartikel (refereegranskat)abstract
- In this review holographic interferometry and electron speckle pattern interferometry are discussed as efficient techniques for diffusion measurements in biochemical and pharmaceutical applications. Transport phenomena can be studied, quantitatively and qualitatively, in gels, liquids and membranes. Detailed information on these phenomena is required to design effective chromatography bioseparation processes using gel beads or ultrafiltration membranes, and in the design of control led-release pharmaceuticals using membrane-coated pellets or tablets. The influence of gel concentration, ion strength in the liquid and the size of diffusing protein molecules can easily be studied with good accuracy. When studying membranes, the resistance can be quantified, and it is also possible to discriminate between permeable and semi-permeable membranes. In this review the influence of temperature, natural convection and light deflection on the accuracy of the diffusion measurements is also discussed. (c) 2008 Elsevier Ltd. All rights reserved.
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| 65. |
- Axelsson Andrén, Elin, 1988, et al.
(författare)
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Low serum HDL-cholesterol is associated with increased risk of the subcortical small vessel type of dementia
- 2024
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Ingår i: Cerebral Circulation - Cognition and Behavior. - 2666-2450. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Background: There are conflicting results whether serum lipid pattern is related to the amount of white matter hyperintensities (WMHs) on magnetic resonance imaging. Little is known of the associations between lipid concentrations and the subsequent risk of the subcortical small vessel type of dementia (SSVD), in which WMHs are a prominent manifestation. Here, we determined whether lipid levels are associated with the risk of SSVD, Alzheimer's disease (AD), or mixed dementia (combined AD and SSVD). Methods: This was a longitudinal, prospective study of 329 patients with subjective or objective mild cognitive impairment at baseline. The statistical analyses included Cox proportional hazards regression with adjustments for age, gender, education, body mass index, current smoking, hypertension, diabetes mellitus, and APOE ε4 genotype. Results: During the follow-up (mean 4.1 years), 80 patients converted to dementia [SSVD, n = 15 (5 %); AD, n = 39 (12 %); and mixed dementia, n = 26 (8 %)]. Serum high-density lipoprotein cholesterol (HDL, per SD increase) was inversely associated with the risk of SSVD, whereas triglycerides (TG), low-density lipoprotein cholesterol (LDL)/HDL ratio, and TG/HDL ratio were positively associated with SSVD risk. Furthermore, the lowest HDL tertile was associated with a sevenfold, and the highest tertile of TG/HDL ratio with a threefold, increase in SSVD risk. There were no associations with the risk of AD or mixed dementia after adjustment for covariates. Conclusion: In a memory clinic population, low HDL and high TG/HDL ratio were independent risk factors of SSVD, but not of AD or mixed dementia.
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| 66. |
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| 67. |
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| 68. |
- Axelsson, B., et al.
(författare)
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Lateral forces in wood cutting
- 1991
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Ingår i: Proceedings of the Tenth International Wood Machining Seminar : Oktober 21 - 23, 1991. - : University of California at Berkeley.
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Konferensbidrag (refereegranskat)
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| 69. |
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| 70. |
- Axelsson, Birger, et al.
(författare)
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Milrinone improves diastolic function in coronary artery bypass surgery as assessed by acoustic quantification and peak filling rate : a prospective randomized study
- 2010
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Ingår i: Journal of Cardiothoracic and Vascular Anesthesia. - : Elsevier BV. - 1053-0770 .- 1532-8422. ; 24:2, s. 244-249
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To compare the effects of a bolus dose of milrinone, 50 microg/kg, to placebo on diastolic function (active relaxation) in patients undergoing on-pump coronary artery bypass grafting (CABG).DESIGN: Prospective, randomized, double-blind, placebo-controlled study.SETTING: University hospital.PARTICIPANTS: Twenty-four patients with stable angina and left ventricular ejection fraction >30%, scheduled for elective CABG using cardiopulmonary bypass (CPB), were included.INTERVENTION: Patients were randomized to receive either 50 microg/kg of milrinone (n = 12) or placebo (n = 12) after aortic declamping.MEASUREMENTS AND MAIN RESULTS: The diastolic function of the left ventricle (LV) was measured as peak filling rate (dA/dt [maximal diastolic area change over time]) with transesophageal echocardiography (TEE) using acoustic quantification (AQ) before CPB and 10 minutes after termination of CPB. The normalized peak filling rate (dA/dt)/EDA was also calculated. Active relaxation was statistically significantly increased in the milrinone group compared with the placebo group after CPB.CONCLUSION: Patients undergoing CABG surgery and treated with milrinone after aortic declamping had better diastolic function following cardiopulmonary bypass.
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