| 1. |
- Hyensjö, Marko, et al.
(författare)
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Modelling a Turbulent Dilute Fibre Suspension in a Planar Contraction : Effect of Vane Types, Vane Position and Wall Boundary Layer on Fibre Orientation Distribution
- 2004
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Ingår i: Proceedings of the 5th International Conference on Multiphase Flow, ICMF’04 Yokohama, Japan.
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Konferensbidrag (refereegranskat)abstract
- A model of the effect of turbulence generating vanes and its location in a planar contraction for predicting fibre orientation distribution is proposed. Simultaneously with CFD simulations and with experimental data, the non-dimensional rotational dispersion coefficient has been determined for the extended 1D headbox model. Furthermore the behavior of turbulence generating vanes types, i.e. blunt and tapered, and the location of such has been studied. For different streamlines in the contracting channel, the one dimensional fibre orientation distribution model is solved, and the fibre orientation distribution is studied along streamlines near the vane wall and vane tip and further away. The model reveals the effect of the vane tip and the wall boundary layer on fibre orientation distribution. The boundary layer will for both in the plane of paper and in the plane of contraction wider the fibre orientation distributions, i.e the fibres will be less oriented. For the outlet profile of the contraction the fibre orientation distribution will be more effected by the blunt vane tip than the tapered vane tip. The model is validated with experimental results in literature and a good qualitatively agreement was archived.
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| 2. |
- Hyensjö, Marko, et al.
(författare)
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Modelling the effect of shear flow on fibre orientation anisotropy in a planar contraction
- 2007
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Ingår i: Nordic Pulp & Paper Research Journal. - : Walter de Gruyter GmbH. - 0283-2631 .- 2000-0669. ; 22:3, s. 376-382
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Tidskriftsartikel (refereegranskat)abstract
- The effect of turbulence generating vanes and its location in a planar contraction on fibre orientation anisotropy was studied by mathematical modelling. We use single phase CFD (Computational Fluid Dynamic) modelling as an input for the fibre orientation dispersion model to study the effect of shear flow and turbulence in an accelerated fluid flow on fibre orientation anisotropy. For different streamlines in the contracting channel, the fibre orientation distribution model is solved, and the fibre orientation anisotropy could be studied along streamlines near the vane wall and vane tip and further away downstream. The boundary layer did decrease the fibre orientation anisotropy both in the plane of paper and in the plane of contraction, i.e the fibres were less oriented. For the outlet profile of the contraction the fibre orientation anisotropy was more effected by the blunt vane tip than the tapered one. Experimental results in the literature were used to validate this modelling approach and a good qualitative agreement was achieved.
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| 3. |
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| 4. |
- Hämäläinen, Jari, et al.
(författare)
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Multiobjective Decision Making for Papermaking
- 2004
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Ingår i: CD-Proceedings of MCDM2004, the 17th International Conference on Multiple Criteria Decision Making.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 5. |
- Klemettilä, Jari-Pekka, et al.
(författare)
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Glucagon-like peptide-1 serum levels are associated with weight gain in patients treated with clozapine
- 2021
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Ingår i: Psychiatry Research. - : Elsevier. - 0165-1781 .- 1872-7123. ; 306
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Tidskriftsartikel (refereegranskat)abstract
- Metabolic syndrome and related cardiovascular risk factors are well-known comorbidities among patients with schizophrenia. Biomarkers of these antipsychotic-associated metabolic adverse effects and antipsychotic-induced weight gain are needed. Glucagon-like peptide-1 (GLP-1) is involved in insulin secretion, regulation of satiety, inhibition of food intake, and inhibition of gastric emptying. GLP-1 also induces reduction in body weight. Visfatin/ NAMPT/ PBEF is an adipocytokine secreted by several cells and tissues. Increased plasma visfatin levels have been associated with overweight/obesity, type 2 diabetes mellitus, insulin resistance, metabolic syndrome and cardiovascular diseases, low grade inflammation, and proinflammatory markers. Associations between antipsychotic-induced weight gain and serum visfatin and GLP-1 levels have been little studied in patients with schizophrenia. The aim of the present study was to test the possible role of serum GLP-1 and visfatin level alterations as markers of weight gain in association with metabolic and inflammatory markers in 190 patients (109 male, 81 female) with schizophrenia on clozapine treatment. High serum levels of GLP-1 correlated significantly with higher levels of visfatin, leptin, insulin, HOMA-IR, higher BMI, and weight change among men. Associations between serum visfatin levels and BMI or weight change were not found in the present patients. Serum GLP-1 level seems to be a marker of metabolic risk factors among men with schizophrenia on clozapine treatment. Female patients may be more sensitive to suppressive effects of clozapine on GLP-1 secretion. Patients on clozapine would benefit from GLP-1 agonists as preventive treatment.
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| 6. |
- Oksanen, Minna, et al.
(författare)
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NF-E2-related factor 2 activation boosts antioxidant defenses and ameliorates inflammatory and amyloid properties in human Presenilin-1 mutated Alzheimer's disease astrocytes
- 2020
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Ingår i: GLIA. - : Wiley. - 0894-1491 .- 1098-1136. ; 68:3, s. 589-599
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Tidskriftsartikel (refereegranskat)abstract
- Alzheimer's disease (AD) is a common dementia affecting a vast number of individuals and significantly impairing quality of life. Despite extensive research in animal models and numerous promising treatment trials, there is still no curative treatment for AD. Astrocytes, the most common cell type of the central nervous system, have been shown to play a role in the major AD pathologies, including accumulation of amyloid plaques, neuroinflammation, and oxidative stress. Here, we show that inflammatory stimulation leads to metabolic activation of human astrocytes and reduces amyloid secretion. On the other hand, the activation of oxidative metabolism leads to increased reactive oxygen species production especially in AD astrocytes. While healthy astrocytes increase glutathione (GSH) release to protect the cells, Presenilin-1-mutated AD patient astrocytes do not. Thus, chronic inflammation is likely to induce oxidative damage in AD astrocytes. Activation of NRF2, the major regulator of cellular antioxidant defenses, encoded by the NFE2L2 gene, poses several beneficial effects on AD astrocytes. We report here that the activation of NRF2 pathway reduces amyloid secretion, normalizes cytokine release, and increases GSH secretion in AD astrocytes. NRF2 induction also activates the metabolism of astrocytes and increases the utilization of glycolysis. Taken together, targeting NRF2 in astrocytes could be a potent therapeutic strategy in AD.
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| 7. |
- Pervjakova, Natalia, et al.
(författare)
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Multi-ancestry genome-wide association study of gestational diabetes mellitus highlights genetic links with type 2 diabetes
- 2022
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Ingår i: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 31:19, s. 3377-3391
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Tidskriftsartikel (refereegranskat)abstract
- Gestational diabetes mellitus (GDM) is associated with increased risk of pregnancy complications and adverse perinatal outcomes. GDM often reoccurs and is associated with increased risk of subsequent diagnosis of type 2 diabetes (T2D). To improve our understanding of the aetiological factors and molecular processes driving the occurrence of GDM, including the extent to which these overlap with T2D pathophysiology, the GENetics of Diabetes In Pregnancy (GenDIP) Consortium assembled genome-wide association studies (GWAS) of diverse ancestry in a total of 5485 women with GDM and 347 856 without GDM. Through multi-ancestry meta-analysis, we identified five loci with genome-wide significant association (p < 5x10-8) with GDM, mapping to/near MTNR1B (p = 4.3x10-54), TCF7L2 (p = 4.0x10-16), CDKAL1 (p = 1.6 × 10-14), CDKN2A-CDKN2B (p = 4.1x10-9) and HKDC1 (p = 2.9x10-8). Multiple lines of evidence pointed to the shared pathophysiology of GDM and T2D: (i) four of the five GDM loci (not HKDC1) have been previously reported at genome-wide significance for T2D; (ii) significant enrichment for associations with GDM at previously reported T2D loci; (iii) strong genetic correlation between GDM and T2D; and (iv) enrichment of GDM associations mapping to genomic annotations in diabetes-relevant tissues and transcription factor binding sites. Mendelian randomisation analyses demonstrated significant causal association (5% false discovery rate) of higher body mass index on increased GDM risk. Our results provide support for the hypothesis that GDM and T2D are part of the same underlying pathology but that, as exemplified by the HKDC1 locus, there are genetic determinants of GDM that are specific to glucose regulation in pregnancy.
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| 8. |
- Ruotsalainen, Henri, et al.
(författare)
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Interactive Multiobjective Optimization for IMRT
- 2006
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In this paper, interactive multiobjective optimization for radiotherapy treatmentplanning is studied. The aim of radiotherapy is to destroy a tumor without caus-ing damage to healthy tissue and treatment planning is used to achieve an optimaldose distribution. In intensity modulated radiotherapy (IMRT), the intensity of theincoming radiation flux can be modulated using some aperture such as a multi-leaf collimator. Radiotherapy goals are conflicting and it is impossible to satisfyall the targets simultaneously. Therefore, an interactive multiobjective optimizationmethod for IMRT is used. With this method, the best compromise can be foundfor all the conflicting targets. Results of numerical studies indicate that in this waya radiotherapy expert, called as a decision maker, can conveniently utilize one’sknowledge and expertize and direct the solution process interactively and itera-tively in order to find the best feasible radiotherapy treatment plan. This approachdecreases the number of uninteresting solutions computed and the best solution canbe selected in a case specific way by using the decision maker’s expertize.
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