1. |
- Murari, A., et al.
(författare)
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A control oriented strategy of disruption prediction to avoid the configuration collapse of tokamak reactors
- 2024
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Ingår i: Nature Communications. - 2041-1723 .- 2041-1723. ; 15:1
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Tidskriftsartikel (refereegranskat)abstract
- The objective of thermonuclear fusion consists of producing electricity from the coalescence of light nuclei in high temperature plasmas. The most promising route to fusion envisages the confinement of such plasmas with magnetic fields, whose most studied configuration is the tokamak. Disruptions are catastrophic collapses affecting all tokamak devices and one of the main potential showstoppers on the route to a commercial reactor. In this work we report how, deploying innovative analysis methods on thousands of JET experiments covering the isotopic compositions from hydrogen to full tritium and including the major D-T campaign, the nature of the various forms of collapse is investigated in all phases of the discharges. An original approach to proximity detection has been developed, which allows determining both the probability of and the time interval remaining before an incoming disruption, with adaptive, from scratch, real time compatible techniques. The results indicate that physics based prediction and control tools can be developed, to deploy realistic strategies of disruption avoidance and prevention, meeting the requirements of the next generation of devices.
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- Stroth, U., et al.
(författare)
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Progress from ASDEX Upgrade experiments in preparing the physics basis of ITER operation and DEMO scenario development
- 2022
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 62:4
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Tidskriftsartikel (refereegranskat)abstract
- An overview of recent results obtained at the tokamak ASDEX Upgrade (AUG) is given. A work flow for predictive profile modelling of AUG discharges was established which is able to reproduce experimental H-mode plasma profiles based on engineering parameters only. In the plasma center, theoretical predictions on plasma current redistribution by a dynamo effect were confirmed experimentally. For core transport, the stabilizing effect of fast ion distributions on turbulent transport is shown to be important to explain the core isotope effect and improves the description of hollow low-Z impurity profiles. The L-H power threshold of hydrogen plasmas is not affected by small helium admixtures and it increases continuously from the deuterium to the hydrogen level when the hydrogen concentration is raised from 0 to 100%. One focus of recent campaigns was the search for a fusion relevant integrated plasma scenario without large edge localised modes (ELMs). Results from six different ELM-free confinement regimes are compared with respect to reactor relevance: ELM suppression by magnetic perturbation coils could be attributed to toroidally asymmetric turbulent fluctuations in the vicinity of the separatrix. Stable improved confinement mode plasma phases with a detached inner divertor were obtained using a feedback control of the plasma β. The enhanced D α H-mode regime was extended to higher heating power by feedback controlled radiative cooling with argon. The quasi-coherent exhaust regime was developed into an integrated scenario at high heating power and energy confinement, with a detached divertor and without large ELMs. Small ELMs close to the separatrix lead to peeling-ballooning stability and quasi continuous power exhaust. Helium beam density fluctuation measurements confirm that transport close to the separatrix is important to achieve the different ELM-free regimes. Based on separatrix plasma parameters and interchange-drift-Alfvén turbulence, an analytic model was derived that reproduces the experimentally found important operational boundaries of the density limit and between L- and H-mode confinement. Feedback control for the X-point radiator (XPR) position was established as an important element for divertor detachment control. Stable and detached ELM-free phases with H-mode confinement quality were obtained when the XPR was moved 10 cm above the X-point. Investigations of the plasma in the future flexible snow-flake divertor of AUG by means of first SOLPS-ITER simulations with drifts activated predict beneficial detachment properties and the activation of an additional strike point by the drifts.
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6. |
- Meyer, H.F., et al.
(författare)
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Overview of physics studies on ASDEX Upgrade
- 2019
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 59:11
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Forskningsöversikt (refereegranskat)abstract
- The ASDEX Upgrade (AUG) programme, jointly run with the EUROfusion MST1 task force, continues to significantly enhance the physics base of ITER and DEMO. Here, the full tungsten wall is a key asset for extrapolating to future devices. The high overall heating power, flexible heating mix and comprehensive diagnostic set allows studies ranging from mimicking the scrape-off-layer and divertor conditions of ITER and DEMO at high density to fully non-inductive operation (q 95 = 5.5, ) at low density. Higher installed electron cyclotron resonance heating power 6 MW, new diagnostics and improved analysis techniques have further enhanced the capabilities of AUG. Stable high-density H-modes with MW m-1 with fully detached strike-points have been demonstrated. The ballooning instability close to the separatrix has been identified as a potential cause leading to the H-mode density limit and is also found to play an important role for the access to small edge-localized modes (ELMs). Density limit disruptions have been successfully avoided using a path-oriented approach to disruption handling and progress has been made in understanding the dissipation and avoidance of runaway electron beams. ELM suppression with resonant magnetic perturbations is now routinely achieved reaching transiently . This gives new insight into the field penetration physics, in particular with respect to plasma flows. Modelling agrees well with plasma response measurements and a helically localised ballooning structure observed prior to the ELM is evidence for the changed edge stability due to the magnetic perturbations. The impact of 3D perturbations on heat load patterns and fast-ion losses have been further elaborated. Progress has also been made in understanding the ELM cycle itself. Here, new fast measurements of and E r allow for inter ELM transport analysis confirming that E r is dominated by the diamagnetic term even for fast timescales. New analysis techniques allow detailed comparison of the ELM crash and are in good agreement with nonlinear MHD modelling. The observation of accelerated ions during the ELM crash can be seen as evidence for the reconnection during the ELM. As type-I ELMs (even mitigated) are likely not a viable operational regime in DEMO studies of 'natural' no ELM regimes have been extended. Stable I-modes up to have been characterised using -feedback. Core physics has been advanced by more detailed characterisation of the turbulence with new measurements such as the eddy tilt angle - measured for the first time - or the cross-phase angle of and fluctuations. These new data put strong constraints on gyro-kinetic turbulence modelling. In addition, carefully executed studies in different main species (H, D and He) and with different heating mixes highlight the importance of the collisional energy exchange for interpreting energy confinement. A new regime with a hollow profile now gives access to regimes mimicking aspects of burning plasma conditions and lead to nonlinear interactions of energetic particle modes despite the sub-Alfvénic beam energy. This will help to validate the fast-ion codes for predicting ITER and DEMO.
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7. |
- Labit, B., et al.
(författare)
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Dependence on plasma shape and plasma fueling for small edge-localized mode regimes in TCV and ASDEX Upgrade
- 2019
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 59:8
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Tidskriftsartikel (refereegranskat)abstract
- © 2019 Institute of Physics Publishing. All rights reserved. Within the EUROfusion MST1 work package, a series of experiments has been conducted on AUG and TCV devices to disentangle the role of plasma fueling and plasma shape for the onset of small ELM regimes. On both devices, small ELM regimes with high confinement are achieved if and only if two conditions are fulfilled at the same time. Firstly, the plasma density at the separatrix must be large enough (ne,sep/nG ∼ 0.3), leading to a pressure profile flattening at the separatrix, which stabilizes type-I ELMs. Secondly, the magnetic configuration has to be close to a double null (DN), leading to a reduction of the magnetic shear in the extreme vicinity of the separatrix. As a consequence, its stabilizing effect on ballooning modes is weakened.
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8. |
- Shcherbina, L., et al.
(författare)
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Intestinal CART is a regulator of GIP and GLP-1 secretion and expression
- 2018
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Ingår i: Molecular and Cellular Endocrinology. - : Elsevier BV. - 0303-7207. ; 476, s. 8-16
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Tidskriftsartikel (refereegranskat)abstract
- Impaired incretin effect is a culprit in Type 2 Diabetes. Cocaine- and amphetamine-regulated transcript (CART) is a regulatory peptide controlling pancreatic islet hormone secretion and beta-cell survival. Here we studied the potential expression of CART in enteroendocrine cells and examined the role of CART as a regulator of incretin secretion and expression. CART expression was found in glucose-dependent insulinotropic polypeptide (GIP)-producing K-cells and glucagon-like peptide-1 (GLP-1)-producing L-cells in human duodenum and jejunum and circulating CART levels were increased 60 min after a meal in humans. CART expression was increased by fatty acids and GIP, but unaffected by glucose in GLUTag and STC-1 cells. Exogenous CART had no effect on GIP and GLP-1 expression and secretion in GLUTag or STC-1 cells, but siRNA-mediated silencing of CART reduced GLP-1 expression and secretion. Furthermore, acute intravenous administration of CART increased GIP and GLP-1 secretion during an oral glucose-tolerance test in mice. We conclude that CART is a novel constituent of human K- and L-cells with stimulatory actions on incretin secretion and that interfering with the CART system may be a therapeutic avenue for T2D.
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14. |
- Coburn, J., et al.
(författare)
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Energy deposition and melt deformation on the ITER first wall due to disruptions and vertical displacement events
- 2022
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 0029-5515 .- 1741-4326. ; 62:1
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Tidskriftsartikel (refereegranskat)abstract
- An analysis workflow has been developed to assess energy deposition and material damage for ITER vertical displacement events (VDEs) and major disruptions (MD). This paper describes the use of this workflow to assess the melt damage to be expected during unmitigated current quench (CQ) phases of VDEs and MDs at different points in the ITER research plan. The plasma scenarios are modeled using the DINA code with variations in plasma current I (p), disruption direction (upwards or downwards), Be impurity density n (Be), and diffusion coefficient chi. Magnetic field line tracing using SMITER calculates time-dependent, 3D maps of surface power density q (perpendicular to) on the Be-armored first wall panels (FWPs) throughout the CQ. MEMOS-U determines the temperature response, macroscopic melt motion, and final surface topology of each FWP. Effects of Be vapor shielding are included. Scenarios at the baseline combination of I (p) and toroidal field (15 MA/5.3 T) show the most extreme melt damage, with the assumed n (Be) having a strong impact on the disruption duration, peak q (perpendicular to) and total energy deposition to the first wall. The worst-cases are upward 15 MA VDEs and MDs at lower values of n (Be), with q (perpendicular to,max) = 307 MW m(-2) and maximum erosion losses of similar to 2 mm after timespans of similar to 400-500 ms. All scenarios at 5 MA avoided melt damage, and only one 7.5 MA scenario yields a notable erosion depth of 0.25 mm. These results imply that disruptions during 5 MA, and some 7.5 MA, operating scenarios will be acceptable during the pre-fusion power operation phases of ITER. Preliminary analysis shows that localized melt damage for the worst-case disruption should have a limited impact on subsequent stationary power handling capability.
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18. |
- Pesce, S., et al.
(författare)
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miRNAs in NK Cell-Based Immune Responses and Cancer Immunotherapy
- 2020
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Ingår i: Frontiers in Cell and Developmental Biology. - : Frontiers Media SA. - 2296-634X. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- The incidence of certain forms of tumors has increased progressively in recent years and is expected to continue growing as life expectancy continues to increase. Tumor-infiltrating NK cells may contribute to develop an anti-tumor response. Optimized combinations of different cancer therapies, including NK cell-based approaches for targeting tumor cells, have the potential to open new avenues in cancer immunotherapy. Functional inhibitory receptors on NK cells are needed to prevent their attack on healthy cells. Nevertheless, disruption of inhibitory receptors function on NK cells increases the cytotoxic capacity of NK cells against cancer cells. MicroRNAs (miRNAs) are small non-coding RNA molecules that target mRNA and thus regulate the expression of genes involved in the development, maturation, and effector functions of NK cells. Therapeutic strategies that target the regulatory effects of miRNAs have the potential to improve the efficiency of cancer immunotherapy. Interestingly, emerging evidence points out that some miRNAs can, directly and indirectly, control the surface expression of immune checkpoints on NK cells or that of their ligands on tumor cells. This suggests a possible use of miRNAs in the context of anti-tumor therapy. This review provides the current overview of the connections between miRNAs and regulation of NK cell functions and discusses the potential of these miRNAs as innovative biomarkers/targets for cancer immunotherapy.
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19. |
- Riise, Rebecca E, 1987, et al.
(författare)
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TLR-Stimulated Neutrophils Instruct NK Cells To Trigger Dendritic Cell Maturation and Promote Adaptive T Cell Responses
- 2015
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Ingår i: Journal of Immunology. - : The American Association of Immunologists. - 0022-1767 .- 1550-6606. ; 195:3, s. 1121-1128
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Tidskriftsartikel (refereegranskat)abstract
- Polymorphonuclear neutrophils (PMNs) are innate effector cells with pivotal roles in pathogen recognition, phagocytosis, and eradication. However, their role in the development of subsequent immune responses is incompletely understood. This study aimed to identify mechanisms of relevance to the cross talk between human neutrophils and NK cells and its potential role in promoting adaptive immunity. TLR-stimulated PMNs were found to release soluble mediators to attract and activate NK cells in vitro. PMN-conditioned NK cells displayed enhanced cytotoxicity and cytokine production, and responded vigorously to ensuing stimulation with exogenous and endogenous IL-12. The neutrophil-induced activation of NK cells was prevented by caspase-1 inhibitors and by natural antagonists to IL-1 and IL-18, suggesting a role for the NOD-like receptor family pyrin domain containing-3 inflammasome. In addition, PMN-conditioned NK cells triggered the maturation of monocyte-derived dendritic cells, which promoted T cell proliferation and IFN-gamma production. These data imply that neutrophils attract NK cells to sites of infection to convert these cells into an active state, which drives adaptive immune responses via maturation of dendritic cells. Our results add to a growing body of evidence that suggests a sophisticated role for neutrophils in orchestrating the immune response to pathogens.
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22. |
- Andersson, Maria L.E. 1968-, et al.
(författare)
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Associations Between Chronic Widespread Pain, Pressure Pain Thresholds and Leptin in Individuals with Knee Pain
- 2022
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Previous studies have reported associations between obesity, chronic pain and increased pain sensitivity. The adipokine leptin has been suggested to be involved in the osteoarthritis process as well as in pain sensitisation.ObjectivesThe aim was to study associations between chronic widespread pain, pain sensitivity and leptin in individuals with knee pain.MethodsIn all, 306 individuals with knee pain were included in the Halland osteoarthritis cohort, ClinicalTrials.gov NCT04928170. Of those, 265 were included in this cross-sectional baseline study. The mean age (sd) was 51.6 (8.8) years, and 71% was women. The participants marked their painful areas on a pain figure with 18 predefined areas. They were categorised in three different pain groups according to the modified WP2019 definition (1), with knees excluded (due to highest goodness of fit): Chronic widespread pain (CWP), chronic regional pain (ChRP) if CWP was not met, and no chronic pain (NCP). The group with CWP were compared with those reporting no CWP (ChRP and NCP). The pressure pain thresholds (PPT) were measured using a computerised pressure algometry (AlgoMed, Medoc) on eight predefined tender points (trapezius (bilateral), right second rib, right lateral epicondyle, knees, gluteal (bilateral)) (2). Increased pain sensitivity was defined as having PPT in the lowest third in all tender points. Obesity was measured via waistline measurement and a bioimpedance (InBody 770) measuring BMI and visceral fat area (VFA). Serum-Leptin were analysed with an ELISA method (Alpco). Knee Injury and Osteoarthritis Outcome Score (KOOS) was used to describe the groups.ResultsIn this baseline study, 16% reported CWP, and 15% had low pain pressure thresholds at baseline in the study. Those fulfilling CWP were more often women, had higher BMI, VFA, and increased leptin levels and worse KOOS in four of five subscores, see Table 1A. The age and gender-adjusted leptin levels were 21.6 ng/ml (95% CI 18.2-25.0) in the group with no CWP vs. 35.5 ng/ml (95% CI 27.6-43.4) in the CWP group, p=0.002. In a logistic regression adjusting for age and gender, leptin was associated with reporting CWP OR 1.015 (95% CI 1.004-1.027, p= 0.008).Table 1.A Comparisons between those without CWP and those fulfilling CWP and table 1B comparisons between those not having low PPT and those with low PPT.ABNo CWPMean (sd)CWPMean (sd)p-valueNot Low PPTMean (sd)Low PPTMean (sd)p-valuen2104022639Age51.8 (8.7)52.8 (7.6)0.46552.1 (8.5)48.8 (9.9)0.030Gender, female n(%)67900.00472670.524BMI (kg/m2)26.2 (4.6)28.0 (5.0)0.02226.4 (4.9)27.5 (4.3)0.213VFA (cm2)107 (50)137 (56)0.001110 (54)127 (49)0.088Leptin (ng/ml)21.0 (23.9)39.0 (36.6)<0.00123.0 (26.0)31.8 (31.6)0.061CRP (mg/L)1.9 (2.7)2.2 (2.3)0.6022.0 (2.7)1.9 (1.8)0.825KOOSPain (0-100, worst to best)74 (15)61 (17)<0.00173 (15)65 (18)0.002Symptom (0-100, worst to best)72 (17)64 (18)0.01671 (17)67 (19)0.188ADL (0-100, worst to best)84 (13)69 (19)<0.00184 (14)72 (21)<0.001Sport/rec (0-100, worst to best)49 (26)34 (27)0.00149 (26)36 (25)0.009QoL (0-100, worst to best)53 (18)46 (20)0.05053 (18)45 (21)0.017BMI, body mass index; VFA, visceral fat area; CRP, C-reactive protein; KOOS, knee injury and osteoarthritis outcome score; ADL; function in daily living; sport/Rec, Function in sport and recreation; QOL, knee-related Quality of lifeThe participants with low PPT were younger and had a mean (sd) leptin 31.8 ng/ml (31.6) vs 23.0 (26.0), p=0.061 in the group not having low PPT, Table 1B. In a logistic regression adjusting for age and gender, leptin was associated with low PPT OR 1.016 (95% CI 1.004-1.029, p= 0.012).ConclusionThe pathophysiological mechanism causing widespread pain is probably multifactorial, involving both biological and physical factors. The adipokine leptin could be involved in some of these mechanisms, but longitudinal studies are needed to be able to study causal relationships.References[1]Wolfe F, et al. Scand J Pain. 2019;20:77-86.[2]Wolfe F, et al. Arthritis and rheumatism. 1990;33:160-72.Disclosure of InterestsNone declared
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23. |
- Andersson, Maria L.E. 1968-, et al.
(författare)
-
Associations between chronic widespread pain, pressure pain thresholds and leptin in individuals with knee pain
- 2022
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Background: Previous studies have reported associations between obesity, chronic pain and increased pain sensitivity. The adipokine leptin has been suggested to be involved in the osteoarthritis process as well as in pain sensitisation.Objective: The aim was to study associations between chronic widespread pain, pain sensitivity and leptin in individuals with knee pain.Method: In all, 306 individuals with knee pain were included in the Halland osteoarthritis cohort, ClinicalTrials.gov NCT04928170. Of those, 265 were included in this cross-sectional baseline study. The mean age (sd) was 51.6 (8.8) years, and 71% was women. The participants marked their painful areas on a pain figure with 18 predefined areas. According to their answer, they were categorised in three different pain groups according to the modified WP2019 definition (1), with knees excluded (due to highest goodness of fit): Chronic widespread pain (CWP), chronic regional pain (ChRP) if CWP was not met, and no chronic pain (NCP). The groupwith CWP were compared with those reporting no CWP (ChRP and NCP). The pressure pain thresholds (PPT) were measured using a computerised pressure algometry (AlgoMed, Medoc) on eight predefined tender points (trapezius (bilateral), right second rib, right lateral epicondyle, knees, gluteal (bilateral)) out of the total 18 points that are part of the definition of fibromyalgia (2). Increased pain sensitivity was defined as having PPT in the lowest third in all tender points. Obesity was measured via waistline measurement and a bioimpedance (InBody 770) measuring BMI, visceral fat area (VFA), and body fat percentage. Serum-Leptin were analysed with an ELISA method (Alpco). C-reactive protein (CRP) >1.0 mg/L were measured according to the current laboratory standards in Sweden. CRP below 1.0 mg/L, were further analysed with a sensitive CRP enzyme-linked immunosorbent assay (ELISA) method (Abnova). Knee Injury and Osteoarthritis Outcome Score (KOOS) was used to describe the groups.Result: In this baseline study, 16% reported CWP, and 15% had low pain pressure thresholds at baseline in the study. Those fulfilling CWP were more often women, had higher BMI, VFA, and increased leptin levels and worse KOOS in four of five subscores, see table 1A. The age and gender-adjusted leptin levels were 21.6 ng/ml (95% CI 18.2-25.0) in the group with no CWP vs. 35.5 ng/ml (95% CI 27.6-43.4) in the CWP group, p=0.002. In a logistic regression adjusting for age and gender, leptin was associated with reporting CWP OR 1.015 (95% CI 1.004-1.027, p= 0.008).The participants with low PPT were younger and had a mean (sd) leptin 31.8 ng/ml (31.6) vs 23.0 (26.0), p=0.061 in the group not having low PPT, table 1B. In a logistic regression adjusting for age and gender, leptin was associated with low PPT OR 1.016 (95% CI 1.004-1.029, p= 0.012).There were no increased CRP levels in any of the pain groups (CWP and low PPT), table 1A and B.Conclusion: The pathophysiological mechanism causing widespread pain is probably multifactorial, involving both biological and physical factors. The adipokin leptin could be involved in some of these mechanisms, but longitudinal studies are needed to be able to study causal relationships.
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24. |
- Andersson, Maria L.E. 1968-, et al.
(författare)
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Associations between chronic widespread pain, pressure pain thresholds, leptin, and metabolic factors in individuals with knee pain
- 2023
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Ingår i: BMC Musculoskeletal Disorders. - London : BioMed Central (BMC). - 1471-2474. ; 24:1
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The aim was to study associations between chronic widespread pain, widespread pain sensitivity, leptin, and metabolic factors in individuals with knee pain. A secondary aim was to study these associations in a subgroup of individuals with normal BMI.METHOD: This cross-sectional study included 265 individuals. The participants were categorised into three different pain groups: Chronic widespread pain (CWP), chronic regional pain (ChRP), or no chronic pain (NCP). The pressure pain thresholds (PPTs) were assessed using computerised pressure algometry. Low PPTs were defined as having PPTs in the lowest third of all tender points. Leptin and metabolic factors such as BMI, visceral fat area (VFA), lipids, and glucose were also assessed.RESULT: Sixteen per cent reported CWP, 15% had low PPTs, and 4% fulfilled both criteria. Those who fulfilled the criteria for CWP were more often women, more obese, and had increased leptin levels. In logistic regression, adjusted for age and gender, leptin was associated with fulfilling criteria for CWP, OR 1.015 (95% CI 1.004-1.027, p = 0.008). In logistic regression, adjusted for age and gender, leptin was associated with low PPTs, OR 1.016 (95% CI 1.004-1.029, p = 0.012). Leptin was also associated with fulfilling both criteria, adjusted for age, sex, and visceral fat area (VFA), OR 1.030 (95% CI 1.001-1.060), p = 0.040.CONCLUSION: Leptin was associated with fulfilling the combined criteria for chronic widespread pain and low PPTs, even after adjusting for the visceral fat area (VFA). Longitudinal studies are needed to study the causal relationships between leptin and the development of widespread pain.
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25. |
- Aurelius, Johan, 1980, et al.
(författare)
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Chronic myeloid leukemic cells trigger poly(ADP-ribose) polymerase-dependent inactivation and cell death in lymphocytes.
- 2013
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Ingår i: Journal of leukocyte biology. - : Oxford University Press (OUP). - 1938-3673 .- 0741-5400. ; 93:1, s. 155-160
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Tidskriftsartikel (refereegranskat)abstract
- NK cells and T cells are commonly dysfunctional in CML, and their status may determine the course of disease. We aimed to define the molecular mechanisms of leukemia-induced immunosuppression with focus on the role of ROS and the PARP-1 pathway of cell death. Malignant granulocytes from patients with BCR-ABL-positive CML expressed the oxygen radical-producing enzyme NOX, produced large amounts of ROS, and triggered extensive cell death in NK cells. Inhibition of PARP-1 maintained NK cell viability in cocultures with suppressive leukemic cells. Under conditions of oxidative stress, PARP-1 inhibition upheld the capacity of NK cells to kill myeloid leukemic cells, in addition to restoring the proliferation and cytokine production of NK cells and cytotoxic T cells. Our findings are suggestive of a novel pathway of relevance to immunosuppression in CML.
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26. |
- Aurelius, Johan, 1980, et al.
(författare)
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NOX2-dependent immunosuppression in chronic myelomonocytic leukemia
- 2017
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Ingår i: Journal of Leukocyte Biology. - 0741-5400 .- 1938-3673. ; 102:2, s. 459-466
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Tidskriftsartikel (refereegranskat)abstract
- Chronic myelomonocytic leukemia (CMML) is a myeloproliferative and myelodysplastic neoplasm with few treatment options and dismal prognosis. The role of natural killer (NK) cells and other antileukemic lymphocytes in CMML is largely unknown. We aimed to provide insight into the mechanisms of immune evasion in CMML with a focus on immunosuppressive reactive oxygen species (ROS) formed by the myeloid cell NADPH oxidase-2 (NOX2). The dominant population of primary human CMML cells was found to express membrane-bound NOX2 and to release ROS, which, in turn, triggered extensive PARP-1-dependent cell death in cocultured NK cells, CD8(+) T effector memory cells, and CD8(+) T effector cells. Inhibitors of ROS formation and scavengers of extracellular ROS prevented CMML cell-induced lymphocyte death and facilitated NK cell degranulation toward Ab-coated, primary CMML cells. In patients with CMML, elevation of immature cell counts (CD34(+)) in blood was associated with reduced expression of several NK cell-activating receptors. We propose that CMML cells may use extracellular ROS as a targetable mechanism of immune escape.
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27. |
- Barbu, Mikael, et al.
(författare)
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Hemostatic effects of a dextran-based priming solution for cardiopulmonary bypass: A secondary analysis of a randomized clinical trial
- 2023
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Ingår i: Thrombosis Research. - : Elsevier BV. - 0049-3848. ; 223, s. 139-145
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Intravascular fluids administered to patients may influence hemostasis. In patients undergoing cardiac surgery with cardiopulmonary bypass, the heart-lung machine is primed with 1300 ml of fluid. We assessed postoperative coagulation and platelet function in patients randomized to two different priming solu-tions, one colloid-based (dextran 40) and one crystalloid-based.Materials and methods: Eighty-four elective cardiac surgery patients were randomized to either a dextran-based prime or Ringer's acetate with added mannitol. Blood samples were collected before, and 2 and 24 h after cardiopulmonary bypass. Coagulation was assessed by standard coagulation tests and rotational thromboelas-tometry. Platelet function was assessed with impedance aggregometry. Bleeding volumes and transfusion re-quirements were recorded.Results: Comparing the groups 2 h after bypass, the dextran group showed lower hemoglobin concentration, hematocrit, platelet count, and fibrinogen concentration, and higher INR and aPTT, as well as longer clot for-mation time (+41 +/- 21 % vs. +8 +/- 18 %, p < 0.001) and a larger reduction in fibrinogen-dependent clot strength (-37 +/- 12 % vs.-7 +/- 20 %, p < 0.001). Adenosine diphosphate-dependent platelet activation was reduced in the dextran group but not in the crystalloid group 2 h after bypass (-14 +/- 29 % vs.-1 +/- 41 %, p = 0.041). No significant between-group differences in hemostatic variables remained after 24 h, and no significant differences in perioperative bleeding volumes, re-explorations for bleeding, or transfusion rates were observed.Conclusions: Compared to a crystalloid solution, a dextran-based prime had measurable negative impact on he-mostatic variables but no detectable increase in bleeding volume or transfusion requirements in cardiac surgery patients.
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28. |
- Benrick, Anna, 1979, et al.
(författare)
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Autonomic nervous system activation mediates the increase in whole-body glucose uptake in response to electroacupuncture
- 2017
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Ingår i: Faseb Journal. - : Federation of American Societies for Experimental Biology. - 0892-6638 .- 1530-6860. ; 31:8, s. 3288-3297
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Tidskriftsartikel (refereegranskat)abstract
- A single bout of low-frequency electroacupuncture (EA) causing muscle contractions increases whole-body glucose uptake in insulin-resistant rats. We explored the underlying mechanism of this finding and whether it can be translated into clinical settings. Changes in glucose infusion rate (GIR) were measured by euglycemic-hyperinsulinemic clamp during and after 45 min of low-frequency EA in 21 overweight/obese women with polycystic ovary syndrome (PCOS) and 21 controls matched for age, weight, and body mass index (experiment 1) and in rats receiving autonomic receptor blockers (experiment 2). GIR was higher after EA in controls and women with PCOS. Plasma serotonin levels and homovanillic acid, markers of vagal activity, decreased in both controls and patients with PCOS. Adipose tissue expression of pro-nerve growth factor (proNGF) decreased, and the mature NGF/proNGF ratio increased after EA in PCOS, but not in controls, suggesting increased sympathetic-driven adipose tissue metabolism. Administration of alpha-/beta-adrenergic receptor blockers in rats blocked the increase in GIR in response to EA. Muscarinic and dopamine receptor antagonist also blocked the response but with slower onset. In conclusion, a single bout of EA increases whole-body glucose uptake by activation of the sympathetic and partly the parasympathetic nervous systems, which could have important clinical implications for the treatment of insulin resistance.
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29. |
- Bergh Thorén, Fredrik, 1976, et al.
(författare)
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Human NK Cells induce neutrophil apoptosis via an NKp46- and Fas-dependent mechanism.
- 2012
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Ingår i: Journal of immunology (Baltimore, Md. : 1950). - : The American Association of Immunologists. - 1550-6606 .- 0022-1767. ; 188:4, s. 1668-74
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Tidskriftsartikel (refereegranskat)abstract
- Polymorphonuclear neutrophils (PMN) are potent inflammatory effector cells essential to host defense, but at the same time they may cause significant tissue damage. Thus, timely induction of neutrophil apoptosis is crucial to avoid tissue damage and induce resolution of inflammation. NK cells have been reported to influence innate and adaptive immune responses by multiple mechanisms including cytotoxicity against other immune cells. In this study, we analyzed the effect of the interaction between NK cells and neutrophils. Coculture experiments revealed that human NK cells could trigger caspase-dependent neutrophil apoptosis in vitro. This event was dependent on cell-cell contact, and experiments using blocking Abs indicated that the effect was mediated by the activating NK cell receptor NKp46 and the Fas pathway. CD56-depleted lymphocytes had minimal effects on neutrophil survival, suggesting that the ability to induce neutrophil apoptosis is specific to NK cells. Our findings provide evidence that NK cells may accelerate neutrophil apoptosis, and that this interaction may be involved in the resolution of acute inflammation.
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30. |
- Bernson, Elin, 1987, et al.
(författare)
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Downregulation of HLA Class I Renders Inflammatory Neutrophils More Susceptible to NK Cell-Induced Apoptosis
- 2019
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Ingår i: Frontiers in Immunology. - : Frontiers Media SA. - 1664-3224. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Neutrophils are potent effector cells and contain a battery of harmful substances and degrading enzymes. A silent neutrophil death, i.e., apoptosis, is therefore of importance to avoid damage to the surrounding tissue and to enable termination of the acute inflammatory process. There is a pile of evidence supporting the role for pro-inflammatory cytokines in extending the life-span of neutrophils, but relatively few studies have been devoted to mechanisms actively driving apoptosis induction in neutrophils. We have previously demonstrated that natural killer (NK) cells can promote apoptosis in healthy neutrophils. In this study, we set out to investigate how neutrophil sensitivity to NK cell-mediated cytotoxicity is regulated under inflammatory conditions. Using in vitro-activated neutrophils and a human skin chamber model that allowed collection of in vivo-transmigrated neutrophils, we performed a comprehensive characterization of neutrophil expression of ligands to NK cell receptors. These studies revealed a dramatic downregulation of HLA class I molecules in inflammatory neutrophils, which was associated with an enhanced susceptibility to NK cell cytotoxicity. Collectively, our data shed light on the complex regulation of interactions between NK cells and neutrophils during an inflammatory response and provide further support for a role of NK cells in the resolution phase of inflammation.
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32. |
- Chuang, Tzu-Po, et al.
(författare)
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ALK fusion NSCLC oncogenes promote survival and inhibit NK cell responses via SERPINB4 expression
- 2023
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Ingår i: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 120:8
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Tidskriftsartikel (refereegranskat)abstract
- Anaplastic lymphoma kinase (ALK) fusion variants in Non-Small Cell Lung Cancer (NSCLC) consist of numerous dimerizing fusion partners. Retrospective investigations suggest that treatment benefit in response to ALK tyrosine kinase inhibitors (TKIs) differs dependent on the fusion variant present in the patient tumor. Therefore, under -standing the oncogenic signaling networks driven by different ALK fusion variants is important. To do this, we developed controlled inducible cell models expressing either Echinoderm Microtubule Associated Protein Like 4 (EML4)-ALK-V1, EML4-ALK-V3, Kinesin Family Member 5B (KIF5B)-ALK, or TRK-fused gene (TFG)-ALK and investi-gated their transcriptomic and proteomic responses to ALK activity modulation together with patient-derived ALK-positive NSCLC cell lines. This allowed identification of both common and isoform-specific responses downstream of these four ALK fusions. An inflammatory signature that included upregulation of the Serpin B4 serine protease inhibitor was observed in both ALK fusion inducible and patient-derived cells. We show that Signal transducer and activator of transcription 3 (STAT3), Nuclear Factor Kappa B (NF-kappa B) and Activator protein 1 (AP1) are major transcriptional regulators of SERPINB4 downstream of ALK fusions. Upregulation of SERPINB4promotes survival and inhibits natural killer cell-mediated cytotoxicity, which has potential for therapeutic impact targeting the immune response together with ALK TKIs in NSCLC.
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33. |
- Coburn, J., et al.
(författare)
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Reassessing energy deposition for the ITER 5 MA vertical displacement event with an improved DINA model
- 2021
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Ingår i: Nuclear Materials and Energy. - : Elsevier BV. - 2352-1791. ; 28
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Tidskriftsartikel (refereegranskat)abstract
- The beryllium (Be) main chamber wall interaction during a 5 MA/1.8 T upward, unmitigated VDE scenario, first analysed in [J. Coburn et al., Phys. Scr. T171 (2020) 014076] for ITER, has been re-evaluated using the latest energy deposition analysis software. Updates to the DINA disruption model are summarized, including an improved numerical convergence for the OD power balance, limitations on the safety factor within the plasma core, and the choice to maintain a constant plasma + halo poloidal cross-section. Such updates result in a broad halo region and higher radiated power fractions compared to previous models. The new scenario lasts for similar to 75 ms and deposits similar to 29 MJ of energy, with the radial distribution of parallel heat flux q parallel to(r) resembling an exponential falloff with an effective lambda(q) = 75 -198 mm. A maximum halo width w(h) of 0.52 m at the outboard midplane is observed. SMITER field line tracing and energy deposition simulations calculate a q(perpendicular to,max) of similar to 83 MW/m(2) on the upper first wall panels (FWP). Heat transfer calculations with the MEMOS-U code show that the FWP surface temperature reaches similar to 1000 K, well below the Be melt threshold. Variations of this 5 MA scenario with Be impurity densities from 0 to 3.10(19) m(-3) also remain below the melt threshold despite differences in energy deposition and duration. These results are in contrast to the early study which predicted melt damage to the first wall [J. Coburn et al., Phys. Scr. T171 (2020) 014076], and emphasize the importance of accurate models for the halo width w(h) and the heat flux distribution q parallel to(r) within that halo width. The 2020 halo model in DINA has been compared with halo current experiments on COMPASS, JET, and Alcator C-Mod, and the preliminary results build confidence in the broad halo width predictions. Results for the 5 MA VDE are compared with those for a 15 MA equivalent, generated using the new DINA model. At the higher current, significant melting of the upper FWP is to be expected.
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34. |
- Corre, Y., et al.
(författare)
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Sustained W-melting experiments on actively cooled ITER-like plasma facing unit in WEST
- 2021
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Ingår i: Physica Scripta. - : IOP Publishing. - 0031-8949 .- 1402-4896. ; 96:12
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Tidskriftsartikel (refereegranskat)abstract
- The consequences of tungsten (W) melting on divertor lifetime and plasma operation are high priority issues for ITER. Sustained and controlled W-melting experiment has been achieved for the first time in WEST on a poloidal sharp leading edge of an actively cooled ITER-like plasma facing unit (PFU). A series of dedicated high power steady state plasma discharges were performed to reach the melting point of tungsten. The leading edge was exposed to a parallel heat flux of about 100 MW.m(-2) for up to 5 s providing a melt phase of about 2 s without noticeable impact of melting on plasma operation (radiated power and tungsten impurity content remained stable at constant input power) and no melt ejection were observed. The surface temperature of the MB was monitored by a high spatial resolution (0.1 mm/pixel) infrared camera viewing the melt zone from the top of the machine. The melting discharge was repeated three times resulting in about 6 s accumulated melting duration leading to material displacement from three similar pools. Cumulated on the overall sustained melting periods, this leads to excavation depth of about 230 mu m followed by a re-solidified tungsten bump of 200 mu m in the JxB direction.
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37. |
- Fredholm, BB, et al.
(författare)
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Consequences of eliminating adenosine A(1) receptors in mice
- 2003
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Ingår i: Drug Development Research (Proceedings of the Seventh International Symposium on Adenosine and Adenine Nucleotides - Part 1). - : Wiley. - 1098-2299 .- 0272-4391. ; 58, s. 350-
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Konferensbidrag (refereegranskat)abstract
- The second coding exon of the adenosine A, receptor gene was eliminated by homologous recombination. The phenotype of mice (mixed C57B6/129OlaHsd background) was studied, using siblings from matings of heterozygous mice. Among the offspring the ratio between+/+, +/-and -/-animals was 1:2:1. Over the first half-year-at least-growth and viability were the same in all genotypes. Binding of A(1) ligands was eliminated in-/-mice and halved in+/-mice. Blood pressure was increased in-/-mice and this was paralleled by an increase in plasma renin. Heart rate was unaffected, as was contractility. Furthermore, the response of the perfused heart to ischemia was similar in+/+and -/-hearts. However, remote preconditioning was eliminated in-/-mouse hearts. Tubuloglomerular feedback in the kidney was also lost in-/-mice. The analgesic response to a non-selective adenosing receptor agonist was lost in-/-mice, which also showed hyperalgesia in the tail-flick test. There was a slight hypoactivity in-/-mice, but responses to caffeine were essentially normal. The inhibition of excitatory neurotransmission in hippocampus by adenosine was lost in-/-mice and reduced in+/-mice. Responses to ATP were affected similarly. Hypoxic depression of synaptic transmission was essentially eliminated in hippocampus and hypoxic decrease in spinal respiratory neuron firing was markedly reduced. These results show that adenosine A, receptors play a physiologically important role in the kidney, spinal cord, and hippocampus and that they are critically important in the adaptive responses to hypoxia. (C) 2003 Wiley-Liss, Inc.
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38. |
- He, W., et al.
(författare)
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CYP2D6 genotype predicts tamoxifen discontinuation and drug response : a secondary analysis of the KARISMA trial
- 2021
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Ingår i: Annals of Oncology. - : Elsevier BV. - 0923-7534. ; 32:10, s. 1286-1293
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Tidskriftsartikel (refereegranskat)abstract
- Background: Guidelines regarding whether tamoxifen should be prescribed based on women's cytochrome P450 2D6 (CYP2D6) genotypes are conflicting and have caused confusion. This study aims to investigate if CYP2D6 metabolizer status isa associated with tamoxifen-related endocrine symptoms, tamoxifen discontinuation, and mammographic density change. Patients and methods: We used data from 1440 healthy women who participated the KARISMA dose determination trial. Endocrine symptoms were measured using a modified Functional Assessment of Cancer Therapy – Endocrine Symptoms (FACT-ES) questionnaire. Change in mammographic density was measured and used as a proxy for tamoxifen response. Participants were genotyped and categorized as poor, intermediate, normal, or ultrarapid CYP2D6 metabolizers. Results: The median endoxifen level per mg oral tamoxifen among poor, intermediate, normal and ultrarapid CYP2D6 metabolizers were 0.18 ng/ml, 0.38 ng/ml, 0.56 ng/ml and 0.67 ng/ml, respectively. Ultrarapid CYP2D6 metabolizers were more likely than other groups to report a clinically relevant change in cold sweats, hot flash, mood swings, being irritable, as well as the overall modified FACT-ES score, after taking tamoxifen. The 6-month tamoxifen discontinuation rates among poor, intermediate, normal, and ultrarapid CYP2D6 metabolizers were 25.7%, 23.6%, 28.6%, and 44.4%, respectively. Among those who continued and finished the 6-month tamoxifen intervention, the mean change in dense area among poor, intermediate, normal, and ultrarapid CYP2D6 metabolizers were −0.8 cm2, −4.5 cm2, −4.1 cm2, and −8.0 cm2 respectively. Conclusions: Poor CYP2D6 metabolizers are likely to experience an impaired response to tamoxifen, measured through mammographic density reduction. In contrast, ultrarapid CYP2D6 metabolizers are at risk for exaggerated response with pronounced adverse effects that may lead to treatment discontinuation.
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43. |
- Hoybye, C, et al.
(författare)
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Eating behavior and gastric emptying in adults with Prader-Willi syndrome
- 2007
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Ingår i: Annals of nutrition & metabolism. - : S. Karger AG. - 1421-9697 .- 0250-6807. ; 51:3, s. 264-269
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Tidskriftsartikel (refereegranskat)abstract
- <i>Background/Aims:</i> Prader-Willi syndrome (PWS) is a complex genetic disorder characterized by distinctive physical, behavioral and psychiatric features. One cardinal symptom is excessive eating, often leading to extreme obesity. The etiology of the hyperphagia is unknown, but eating behaviors and gastrointestinal motility could play a pivotal role. In this pilot study, we therefore sought to give a closer description of the two. <i>Methods:</i> 12 PWS adults, 6 men and 6 women, 17–37 years of age with a median BMI of 34.9 were evaluated. Computerized monitoring of eating behavior and assessment of gastric emptying using paracetamol absorption were analyzed. Gastric emptying rate was compared to the rate in normal and obese controls. <i>Results:</i> Eating behavior pattern was nonhomogeneous in the PWS patients, but they experienced both hunger and satiation. In PWS gastric emptying was similar to lean subjects (p > 0.05), but longer than in obese subjects (p < 0.05). <i>Conclusions:</i> Despite obesity, this group of adults with PWS did not display overeating in the test situation and gastric emptying rate was normal. Numbers are small, but the results are important for the treatment of obesity in this special group of patients.
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47. |
- Krieger, K., et al.
(författare)
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Investigation of transient melting of tungsten by ELMs in ASDEX Upgrade
- 2017
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Ingår i: Physica Scripta. - : IOP PUBLISHING LTD. - 0031-8949 .- 1402-4896. ; T170
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Tidskriftsartikel (refereegranskat)abstract
- Repetitive melting of tungsten by power transients originating from edge localized modes (ELMs) has been studied in the tokamak experiment ASDEX Upgrade. Tungsten samples were exposed to H-mode discharges at the outer divertor target plate using the Divertor Manipulator II system. The exposed sample was designed with an elevated sloped surface inclined against the incident magnetic field to increase the projected parallel power flux to a level were transient melting by ELMs would occur. Sample exposure was controlled by moving the outer strike point to the sample location. As extension to previous melt studies in the new experiment both the current flow from the sample to vessel potential and the local surface temperature were measured with sufficient time resolution to resolve individual ELMs. The experiment provided for the first time a direct link of current flow and surface temperature during transient ELM events. This allows to further constrain the MEMOS melt motion code predictions and to improve the validation of its underlying model assumptions. Post exposure ex situ analysis of the retrieved samples confirms the decreased melt motion observed at shallower magnetic field line to surface angles compared to that at leading edges exposed to the parallel power flux.
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