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- Bécoulet, A., et al.
(författare)
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Science and technology research and development in support to ITER and the Broader Approach at CEA
- 2013
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 53:10
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Tidskriftsartikel (refereegranskat)abstract
- In parallel to the direct contribution to the procurement phase of ITER and Broader Approach, CEA has initiated research & development programmes, accompanied by experiments together with a significant modelling effort, aimed at ensuring robust operation, plasma performance, as well as mitigating the risks of the procurement phase. This overview reports the latest progress in both fusion science and technology including many areas, namely the mitigation of superconducting magnet quenches, disruption-generated runaway electrons, edge-localized modes (ELMs), the development of imaging surveillance, and heating and current drive systems for steady-state operation. The WEST (W Environment for Steady-state Tokamaks) project, turning Tore Supra into an actively cooled W-divertor platform open to the ITER partners and industries, is presented.
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2. |
- Rosenling, Therese, et al.
(författare)
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The Impact of Delayed Storage on the Measured Proteome and Metabolome of Human Cerebrospinal Fluid
- 2011
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Ingår i: Clinical Chemistry. - : Oxford University Press (OUP). - 0009-9147 .- 1530-8561. ; 57:12, s. 1703-1711
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Because cerebrospinal fluid (CSF) is in close contact with diseased areas in neurological disorders, it is an important source of material in the search for molecular biomarkers. However, sample handling for CSF collected from patients in a clinical setting might not always be adequate for use in proteomics and metabolomics studies. METHODS: We left CSF for 0, 30, and 120 min at room temperature immediately after sample collection and centrifugation/removal of cells. After tryptic digestion at 2 laboratories by nanoLC Orbitrap-MS and chipLC QTOF-MS, CSF proteomes were analyzed. Metabolome analysis was performed at 3 laboratories by NMR, GC-MS, and LC-MS. Targeted analyses of cystatin C and albumin were performed by LC-MS/MS in the selected reaction monitoring mode. RESULTS: We did not find significant changes in the measured proteome and metabolome of CSF stored at room temperature after centrifugation, except for 2 peptides and 1 metabolite, 2,3,4-trihydrobutanoic acid, of 5780 identified peptides and 93 identified metabolites. A sensitive protein stability marker, cystatin C, was not affected. CONCLUSIONS: The measured proteome and metabolome of centrifuged, human CSF is stable at room temperature for up to 2 hours. We cannot exclude, however, that changes undetectable with our current methodology, such as denaturation or proteolysis, might occur due to sample handling conditions. The stability we observed gives laboratory personnel at the collection site sufficient time to aliquot samples before freezing and storage at -80 °C.
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3. |
- Bolognesi, B, et al.
(författare)
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The N-terminus of amyloid-beta plays a crucial role in its aggregation and toxicity
- 2010
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Ingår i: The FEBS Journal. - : Wiley-Blackwell. - 1742-464X .- 1742-4658. ; 277:Suppl. 1, s. 79-80
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The aggregation of Amyloid Beta (Aß) peptide into insolubleamyloid fibrils that deposit in the brain is one of the primarypathogenic events in Alzheimer’s disease. We have previouslyshown, using a Drosophila model of Aß toxicity, that the N terminus of the Aß peptide, despite being unstructured in themature Aß fibril, nonetheless affects Aß induced neurodegeneration in vivo. In order to understand the contribution of the N terminusof Aß to its aggregation behaviour, we have investigated anumber of rationally designed N-terminal mutants in vitro. We find that single amino acid mutations in this region affect significantlythe kinetics of Aß aggregation in vitro as measured by arange of spectroscopic techniques. Furthermore, we observe striking differences in the morphology of the aggregated speciesformed by these different Aß mutants when imaged with TEM or AFM and also in the ß-sheet content of their mature fibrils. Interestingly, mutants with an increased net charge or lower hydrophobicity tend to show slower aggregation kinetics, and to form more ordered aggregates whereas mutations that reduce net charge or increase hydrophobicity favour faster aggregation kinetics and poorly structured aggregates. In addition, the exposed hydrophobicity of aggregates formed in the early stages of aggregation is correlated to their toxicity. These findings demonstrate not only that the N-terminus of the Aß peptide plays a crucial role in its aggregation and toxicity but also suggest that this region of Aß may modulate in vivo toxicity by altering the conformations of aggregates that it forms.
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4. |
- Brorsson, Ann-Christin, et al.
(författare)
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Intrinsic determinants of neurotoxic aggregate formation by the amyloid beta peptide
- 2010
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Ingår i: Biophysical Journal. - : Elsevier BV. - 0006-3495 .- 1542-0086. ; 98:8, s. 1677-84
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Tidskriftsartikel (refereegranskat)abstract
- The extent to which proteins aggregate into distinct structures ranging from prefibrillar oligomers to amyloid fibrils is key to the pathogenesis of many age-related degenerative diseases. We describe here for the Alzheimer's disease-related amyloid beta peptide (Abeta) an investigation of the sequence-based determinants of the balance between the formation of prefibrillar aggregates and amyloid fibrils. We show that by introducing single-point mutations, it is possible to convert the normally harmless Abeta40 peptide into a pathogenic species by increasing its relative propensity to form prefibrillar but not fibrillar aggregates, and, conversely, to abolish the pathogenicity of the highly neurotoxic E22G Abeta42 peptide by reducing its relative propensity to form prefibrillar species rather than mature fibrillar ones. This observation can be rationalized by the demonstration that whereas regions of the sequence of high aggregation propensity dominate the overall tendency to aggregate, regions with low intrinsic aggregation propensities exert significant control over the balance of the prefibrillar and fibrillar species formed, and therefore play a major role in determining the neurotoxicity of the Abeta peptide.
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5. |
- Lundström, Jan O., et al.
(författare)
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Transstadial Transmission of Francisella tularensis holarctica in Mosquitoes, Sweden
- 2011
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Ingår i: Emerging Infectious Diseases. - : Centers for Disease Control and Prevention (CDC). - 1080-6040 .- 1080-6059. ; 17:5, s. 794-799
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Tidskriftsartikel (refereegranskat)abstract
- In Sweden, human cases of tularemia caused by Francisella tularensis holarctica are assumed to be transmitted by mosquitoes, but how mosquito vectors acquire and transmit the bacterium is not clear. To determine how transmission of this bacterium occurs, mosquito larvae were collected in an area where tularemia is endemic, brought to the laboratory, and reared to adults in their original pond water. Screening of adult mosquitoes by real-time PCR demonstrated F tularensis IpnA sequences in 14 of the 48 mosquito pools tested; IpnA sequences were demonstrated in 6 of 9 identified mosquito species. Further analysis confirmed the presence of F tularensis holarctica-specific 30-bp deletion region sequences (FtM19inDel) in water from breeding containers and in 3 mosquito species (Aedes sticticus, Ae. vexans, and Ae. punctor) known to take blood from humans. Our results suggest that the mosquitoes that transmit F tularensis holarctica during tularemia outbreaks acquire the bacterium already as larvae.
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