| 1. |
- Reimerdes, H., et al.
(författare)
-
Overview of the TCV tokamak experimental programme
- 2022
-
Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 62:4
-
Tidskriftsartikel (refereegranskat)abstract
- The tokamak a configuration variable (TCV) continues to leverage its unique shaping capabilities, flexible heating systems and modern control system to address critical issues in preparation for ITER and a fusion power plant. For the 2019-20 campaign its configurational flexibility has been enhanced with the installation of removable divertor gas baffles, its diagnostic capabilities with an extensive set of upgrades and its heating systems with new dual frequency gyrotrons. The gas baffles reduce coupling between the divertor and the main chamber and allow for detailed investigations on the role of fuelling in general and, together with upgraded boundary diagnostics, test divertor and edge models in particular. The increased heating capabilities broaden the operational regime to include T (e)/T (i) similar to 1 and have stimulated refocussing studies from L-mode to H-mode across a range of research topics. ITER baseline parameters were reached in type-I ELMy H-modes and alternative regimes with 'small' (or no) ELMs explored. Most prominently, negative triangularity was investigated in detail and confirmed as an attractive scenario with H-mode level core confinement but an L-mode edge. Emphasis was also placed on control, where an increased number of observers, actuators and control solutions became available and are now integrated into a generic control framework as will be needed in future devices. The quantity and quality of results of the 2019-20 TCV campaign are a testament to its successful integration within the European research effort alongside a vibrant domestic programme and international collaborations.
|
|
| 2. |
- Bonham, LW, et al.
(författare)
-
Genetic variation across RNA metabolism and cell death gene networks is implicated in the semantic variant of primary progressive aphasia
- 2019
-
Ingår i: Scientific reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 9:1, s. 10854-
-
Tidskriftsartikel (refereegranskat)abstract
- The semantic variant of primary progressive aphasia (svPPA) is a clinical syndrome characterized by neurodegeneration and progressive loss of semantic knowledge. Unlike many other forms of frontotemporal lobar degeneration (FTLD), svPPA has a highly consistent underlying pathology composed of TDP-43 (a regulator of RNA and DNA transcription metabolism). Previous genetic studies of svPPA are limited by small sample sizes and a paucity of common risk variants. Despite this, svPPA’s relatively homogenous clinicopathologic phenotype makes it an ideal investigative model to examine genetic processes that may drive neurodegenerative disease. In this study, we used GWAS metadata, tissue samples from pathologically confirmed frontotemporal lobar degeneration, and in silico techniques to identify and characterize protein interaction networks associated with svPPA risk. We identified 64 svPPA risk genes that interact at the protein level. The protein pathways represented in this svPPA gene network are critical regulators of RNA metabolism and cell death, such as SMAD proteins and NOTCH1. Many of the genes in this network are involved in TDP-43 metabolism. Contrary to the conventional notion that svPPA is a clinical syndrome with few genetic risk factors, our analyses show that svPPA risk is complex and polygenic in nature. Risk for svPPA is likely driven by multiple common variants in genes interacting with TDP-43, along with cell death,x` working in combination to promote neurodegeneration.
|
|
| 3. |
- Ossenkoppele, R., et al.
(författare)
-
Tau PET patterns mirror clinical and neuroanatomical variability in Alzheimer's disease
- 2016
-
Ingår i: Brain. - : Oxford University Press (OUP). - 0006-8950 .- 1460-2156. ; 139, s. 1551-1567
-
Tidskriftsartikel (refereegranskat)abstract
- The PET tracer [F-18]-AV-1451 allows visualization of tau pathology in living subjects. Ossenkoppele et al. employ the tracer in patients with distinct Alzheimer's disease variants to investigate correlates of tau deposition. Pathological aggregation of tau, but not amyloid-beta, is linked to patterns of neurodegeneration and clinical manifestations of Alzheimer's disease.See Sarazin et al. (doi:10.1093/brain/aww041) for a scientific commentary on this article. The PET tracer [F-18]-AV-1451 allows visualization of tau pathology in living subjects. Ossenkoppele et al. employ the tracer in patients with distinct Alzheimer's disease variants to investigate correlates of tau deposition. Pathological aggregation of tau, but not amyloid-beta, is linked to patterns of neurodegeneration and clinical manifestations of Alzheimer's disease.The advent of the positron emission tomography tracer F-18-AV1451 provides the unique opportunity to visualize the regional distribution of tau pathology in the living human brain. In this study, we tested the hypothesis that tau pathology is closely linked to symptomatology and patterns of glucose hypometabolism in Alzheimer's disease, in contrast to the more diffuse distribution of amyloid-beta pathology. We included 20 patients meeting criteria for probable Alzheimer's disease dementia or mild cognitive impairment due to Alzheimer's disease, presenting with a variety of clinical phenotypes, and 15 amyloid-beta-negative cognitively normal individuals, who underwent F-18-AV1451 (tau), C-11-PiB (amyloid-beta) and F-18-FDG (glucose metabolism) positron emission tomography, apolipoprotein E (APOE) genotyping and neuropsychological testing. Voxel-wise contrasts against controls (at P < 0.05 family-wise error corrected) showed that F-18-AV1451 and F-18-FDG patterns in patients with posterior cortical atrophy ('visual variant of Alzheimer's disease', n = 7) specifically targeted the clinically affected posterior brain regions, while C-11-PiB bound diffusely throughout the neocortex. Patients with an amnestic-predominant presentation (n = 5) showed highest F-18-AV1451 retention in medial temporal and lateral temporoparietal regions. Patients with logopenic variant primary progressive aphasia ('language variant of Alzheimer's disease', n = 5) demonstrated asymmetric left greater than right hemisphere F-18-AV1451 uptake in three of five patients. Across 30 FreeSurfer-defined regions of interest in 16 Alzheimer's disease patients with all three positron emission tomography scans available, there was a strong negative association between F-18-AV1451 and F-18-FDG uptake (Pearson's r = -0.49 +/- 0.07, P < 0.001) and less pronounced positive associations between C-11-PiB and F-18-FDG (Pearson's r = 0.16 +/- 0.09, P < 0.001) and F-18-AV1451 and C-11-PiB (Pearson's r = 0.18 +/- 0.09, P < 0.001). Voxel-wise linear regressions thresholded at P < 0.05 (uncorrected) showed that, across all patients, younger age was associated with greater F-18-AV1451 uptake in wide regions of the neocortex, while older age was associated with increased F-18-AV1451 in the medial temporal lobe. APOE I mu 4 carriers showed greater temporal and parietal F-18-AV1451 uptake than non-carriers. Finally, worse performance on domain-specific neuropsychological tests was associated with greater F-18-AV1451 uptake in key regions implicated in memory (medial temporal lobes), visuospatial function (occipital, right temporoparietal cortex) and language (left > right temporoparietal cortex). In conclusion, tau imaging-contrary to amyloid-beta imaging-shows a strong regional association with clinical and anatomical heterogeneity in Alzheimer's disease. Although preliminary, these results are consistent with and expand upon findings from post-mortem, animal and cerebrospinal fluid studies, and suggest that the pathological aggregation of tau is closely linked to patterns of neurodegeneration and clinical manifestations of Alzheimer's disease.
|
|
