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| 2. |
- Herique, A., et al.
(författare)
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Direct observations of asteroid interior and regolith structure : Science measurement requirements
- 2018
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Ingår i: Advances in Space Research. - : Elsevier BV. - 0273-1177 .- 1879-1948. ; 62:8, s. 2141-2162
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Tidskriftsartikel (refereegranskat)abstract
- Our knowledge of the internal structure of asteroids is, so far, indirect - relying entirely on inferences from remote sensing observations of the surface, and theoretical modeling of formation and evolution. What are the bulk properties of the regolith and deep interior? And what are the physical processes that shape asteroid internal structures? Is the composition and size distribution observed on the surface representative of the bulk? These questions are crucial to understand small bodies' history from accretion in the early Solar System to the present, and direct measurements are needed to answer these questions for the benefit of science as well as for planetary defense or exploration. Radar is one of the main instruments capable of sounding asteroids to characterize internal structure from sub-meter to global scale. In this paper, we review the science case for direct observation of the deep internal structure and regolith of a rocky asteroid of kilometer size or smaller. We establish the requirements and model dielectric properties of asteroids to outline a possible instrument suite, and highlight the capabilities of radar instrumentation to achieve these observations. We then review the expected science return including secondary objectives contributing to the determination of the gravitational field, the shape model, and the dynamical state. This work is largely inherited from MarcoPolo-R and AIDA/AIM studies.
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| 3. |
- Jahnke, T., et al.
(författare)
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Inner-Shell-Ionization-Induced Femtosecond Structural Dynamics of Water Molecules Imaged at an X-Ray Free-Electron Laser
- 2021
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Ingår i: Physical Review X. - : American Physical Society. - 2160-3308. ; 11:4
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Tidskriftsartikel (refereegranskat)abstract
- The ultrafast structural dynamics of water following inner-shell ionization is a crucial issue in high-energy radiation chemistry. We have exposed isolated water molecules to a short x-ray pulse from a free-electron laser and detected momenta of all produced ions in coincidence. By combining experimental results and theoretical modeling, we can image dissociation dynamics of individual molecules in unprecedented detail. We reveal significant molecular structural dynamics in H2O2+, such as asymmetric deformation and bond-angle opening, leading to two-body or three-body fragmentation on a timescale of a few femtoseconds. We thus reconstruct several snapshots of structural dynamics at different time intervals, which highlight dynamical patterns that are relevant as initiating steps of subsequent radiation-damage processes.
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| 4. |
- van de Sande-Bruinsma, Nienke, et al.
(författare)
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Antimicrobial drug use and resistance in Europe
- 2008
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Ingår i: Emerging Infectious Diseases. - : Centers for Disease Control and Prevention (CDC). - 1080-6040 .- 1080-6059. ; 14:11, s. 1722-30
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Tidskriftsartikel (refereegranskat)abstract
- Our study confronts the use of antimicrobial agents in ambulatory care with the resistance trends of 2 major pathogens, Streptococcus pneumoniae and Escherichia coli, in 21 European countries in 2000-2005 and explores whether the notion that antimicrobial drug use determines resistance can be supported by surveillance data at national aggregation levels. The data obtained from the European Surveillance of Antimicrobial Consumption and the European Antimicrobial Resistance Surveillance System suggest that variation of consumption coincides with the occurrence of resistance at the country level. Linear regression analysis showed that the association between antimicrobial drug use and resistance was specific and robust for 2 of 3 compound pathogen combinations, stable over time, but not sensitive enough to explain all of the observed variations. Ecologic studies based on routine surveillance data indicate a relation between use and resistance and support interventions designed to reduce antimicrobial drug consumption at a national level in Europe.
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| 7. |
- Wada, K., et al.
(författare)
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Asteroid Ryugu before the Hayabusa2 encounter
- 2018
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Ingår i: Progress in Earth and Planetary Science. - : Springer Science and Business Media LLC. - 2197-4284. ; 5:1
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Tidskriftsartikel (refereegranskat)
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