| 911. |
- Östrom, Henrik, et al.
(författare)
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Probing the transition state region in catalytic CO oxidation on Ru
- 2015
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 347:6225, s. 978-982
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Tidskriftsartikel (refereegranskat)abstract
- Femtosecond x-ray laser pulses are used to probe the carbon monoxide (CO) oxidation reaction on ruthenium (Ru) initiated by an optical laser pulse. On a time scale of a few hundred femtoseconds, the optical laser pulse excites motions of CO and oxygen (O) on the surface, allowing the reactants to collide, and, with a transient close to a picosecond (ps), new electronic states appear in the OK-edge x-ray absorption spectrum. Density functional theory calculations indicate that these result from changes in the adsorption site and bond formation between CO and O with a distribution of OC-O bond lengths close to the transition state (TS). After 1 ps, 10% of the CO populate the TS region, which is consistent with predictions based on a quantum oscillator model.
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| 912. |
- Andersson, DI, et al.
(författare)
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Evidence that gene amplification underlies adaptive mutability of the bacterial lac operon
- 1998
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Ingår i: SCIENCE. - : AMER ASSOC ADVANCEMENT SCIENCE. - 0036-8075. ; 282:5391, s. 1133-1135
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Adaptive mutability is the apparent alteration in specificity or rate of mutability seen in bacteria during stress. A model is proposed by which gene amplification during selective growth can give the appearance of adaptive mutability without requiring an
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| 913. |
- Arrow, K., et al.
(författare)
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Determining Benefits and Costs for Future Generations
- 2013
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Ingår i: Science. - 0036-8075. ; 341:6144, s. 349-350
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Tidskriftsartikel (refereegranskat)abstract
- In economic project analysis, the rate at which future benefits and costs are discounted relative to current values often determines whether a project passes the benefit-cost test. This is especially true of projects with long time horizons, such as those to reduce greenhouse gas (GHG) emissions. Whether the benefits of climate policies, which can last for centuries, outweigh the costs, many of which are borne today, is especially sensitive to the rate at which future benefits are discounted. This is also true of other policies, e.g., affecting nuclear waste disposal or the construction of long-lived infrastructure
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| 914. |
- Arvidsson, R
(författare)
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Fennoscandian earthquakes: Whole crustal rupturing related to postglacial rebound
- 1996
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Ingår i: SCIENCE. - : AMER ASSOC ADVANCEMENT SCIENCE. - 0036-8075. ; 274:5288, s. 744-746
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Local and regional earthquake locations provide seismic evidence that large shield earthquakes have occurred in northern Fennoscandia. These paleoearthquakes, with fault lengths of up to 160 kilometers and average displacements of up to 15 meters, were tr
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| 915. |
- ASKEBJER, P, et al.
(författare)
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OPTICAL-PROPERTIES OF THE SOUTH-POLE ICE AT DEPTHS BETWEEN 0.8 AND 1 KILOMETER
- 1995
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Ingår i: SCIENCE. - : AMER ASSOC ADVAN SCIENCE. - 0036-8075. ; 267:5201, s. 1147-1150
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The optical properties of the ice at the geographical South Pole have been investigated at depths between 0.8 and 1 kilometer. The absorption and scattering lengths of visible light (similar to 515 nanometers) have been measured in situ with the use of th
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| 916. |
- Balusu, Sriram, et al.
(författare)
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MEG3 activates necroptosis in human neuron xenografts modeling Alzheimer's disease.
- 2023
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Ingår i: Science (New York, N.Y.). - 1095-9203. ; 381:6663, s. 1176-1182
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Tidskriftsartikel (refereegranskat)abstract
- Neuronal cell loss is a defining feature of Alzheimer's disease (AD), but the underlying mechanisms remain unclear. We xenografted human or mouse neurons into the brain of a mouse model of AD. Only human neurons displayed tangles, Gallyas silver staining, granulovacuolar neurodegeneration (GVD), phosphorylated tau blood biomarkers, and considerable neuronal cell loss. The long noncoding RNA MEG3 was strongly up-regulated in human neurons. This neuron-specific long noncoding RNA is also up-regulated in AD patients. MEG3 expression alone was sufficient to induce necroptosis in human neurons in vitro. Down-regulation of MEG3 and inhibition of necroptosis using pharmacological or genetic manipulation of receptor-interacting protein kinase 1 (RIPK1), RIPK3, or mixed lineage kinase domain-like protein (MLKL) rescued neuronal cell loss in xenografted human neurons. This model suggests potential therapeutic approaches for AD and reveals a human-specific vulnerability to AD.
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| 917. |
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| 918. |
- Belonoshko, AB
(författare)
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Atomistic simulation of shock wave-induced melting in argon
- 1997
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Ingår i: SCIENCE. - : AMER ASSOC ADVANCEMENT SCIENCE. - 0036-8075. ; 275:5302, s. 955-957
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- A three-dimensional molecular dynamics simulation of shock wave loading was undertaken to investigate the Hugoniot equation of state at the transition of argon from solid to liquid. The simulated data agree with shock wave and static high-pressure experim
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| 919. |
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| 920. |
- Bennett, KD, et al.
(författare)
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The last glacial-holocene transition in southern Chile
- 2000
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Ingår i: SCIENCE. - : AMER ASSOC ADVANCEMENT SCIENCE. - 0036-8075. ; 290:5490, s. 325-328
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Tidskriftsartikel (refereegranskat)abstract
- Warming at the Last glacial termination in the North Atlantic region was interrupted by a period of renewed glacial activity during the Younger Dryas chronozone (YDC). The underlying mechanism of this cooling remains elusive, but hypotheses turn on whethe
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