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- Wang, Chao, 1991-, et al.
(författare)
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FEM based research on the dynamic response of a concrete railway arch bridge
- 2016
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Ingår i: IABSE CONGRESS, STOCKHOLM, 2016. - CH - 8093 Zürich, Switzerland. - 9783857481444 ; , s. 2472-2479
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Konferensbidrag (refereegranskat)abstract
- The dynamic response of a concrete railway arch bridge is studied through a case study of the bridge over Kalix River, situated at Långforsen on the railway line between Kalix and Morjärv in northern Sweden. A simplified beam-element model, a spatial grillage-beam model and a refined shell-element model were built to analyze the bridge structure. A methodology was applied where measured static and dynamic responses were used to update finite element models of Långforsen Bridge. A multi-response objective function was presented, and the finite element method was proved feasible by comparison of predicted and measured response. In the paper comparative analyses were made of the time history displacement of three finite element models under three measured load cases. A standard train model from EUROCODE, HSLM-A 1, was applied and the dynamic responses under different speeds were studied. The results showed that a refined shell element model could accurately analyze dynamic responses of the concrete railway arch bridge in a better way than beam element and spatial grillage models. The dynamic analysis based on this type of shell model can give an optimized suggestion for the railway operation as well as for the design of high-speed railway bridges.
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| 2. |
- Lau, Angus, et al.
(författare)
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alpha-Synuclein strains target distinct brain regions and cell types
- 2020
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Ingår i: Nature Neuroscience. - : NATURE PUBLISHING GROUP. - 1097-6256 .- 1546-1726. ; 23, s. 21-31
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Tidskriftsartikel (refereegranskat)abstract
- The clinical and pathological differences between synucleinopathies such as Parkinson's disease and multiple system atrophy have been postulated to stem from unique strains of alpha-synuclein aggregates, akin to what occurs in prion diseases. Here we demonstrate that inoculation of transgenic mice with different strains of recombinant or brain-derived alpha-synuclein aggregates produces clinically and pathologically distinct diseases. Strain-specific differences were observed in the signs of neurological illness, time to disease onset, morphology of cerebral alpha-synuclein deposits and the conformational properties of the induced aggregates. Moreover, different strains targeted distinct cellular populations and cell types within the brain, recapitulating the selective targeting observed among human synucleinopathies. Strain-specific clinical, pathological and biochemical differences were faithfully maintained after serial passaging, which implies that alpha-synuclein propagates via prion-like conformational templating. Thus, pathogenic alpha-synuclein exhibits key hallmarks of prion strains, which provides evidence that disease heterogeneity among the synucleinopathies is caused by distinct alpha-synuclein strains.
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