| 21. |
- Zhaunerchyk, Vitali, et al.
(författare)
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Disentangling formation of multiple-core holes in aminophenol molecules exposed to bright X-FEL radiation
- 2015
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Ingår i: Journal of Physics B. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 48:24
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Tidskriftsartikel (refereegranskat)abstract
- Competing multi-photon ionization processes, some leading to the formation of double core hole states, have been examined in 4-aminophenol. The experiments used the linac coherent light source (LCLS) x-ray free electron laser, in combination with a time-of-flight magnetic bottle electron spectrometer and the correlation analysis method of covariance mapping. The results imply that 4-aminophenol molecules exposed to the focused x-ray pulses of the LCLS sequentially absorb more than two x-ray photons, resulting in the formation of multiple core holes as well as in the sequential removal of photoelectrons and Auger electrons (so-called PAPA sequences).
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| 22. |
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| 23. |
- Thomas, Richard D., et al.
(författare)
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DESIREE : Physics with cold stored ion beams
- 2015
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Ingår i: DR2013. - : EDP Sciences. ; 84, s. 01004-01004
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Konferensbidrag (refereegranskat)abstract
- Here we will briefly describe the commissioning of the Double ElectroStatic Ion Ring ExpEriment (DESIREE) facility at Stockholm University, Sweden. This device uses purely electrostatic focussing and deflection elements and allows ion beams of opposite charge to be confined under extreme high vacuum and cryogenic conditions in separate rings and then merged over a common straight section. This apparatus allows for studies of interactions between cations and anions at very low and well-defined centre-of-mass energies (down to a few meV) and at very low internal temperatures (down to a few K).
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| 24. |
- Bäckström, Erik, 1983-, et al.
(författare)
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Storing keV negative ions for an hour : The lifetime of the metastable 2P1/2 level in 32S−
- 2015
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 114:14
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Tidskriftsartikel (refereegranskat)abstract
- We use a novel electrostatic ion storage ring to measure the radiative lifetime of the upper level in the 3p 5 P 2 o 1/2 →3p 5 P 2 o 3/2 spontaneous radiative decay in S − 32 to be 503±54 sec . This is by orders of magnitude the longest lifetime ever measured in a negatively charged ion. Cryogenic cooling of the storage ring gives a residual-gas pressure of a few times 10 −14 mbar at 13 K and storage of 10 keV sulfur anions for more than an hour. Our experimental results differ by 1.3σ from the only available theoretical prediction.
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| 25. |
- Chartkunchand, C, et al.
(författare)
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Measuring the 2D3/2 Ni− excited state lifetime in DESIREE
- 2015
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Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 635
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Konferensbidrag (refereegranskat)abstract
- Experimental studies of the radiative lifetime of the sole excited state in the nickel anion are presented. Beams of Ni− stored in DESIREE at cryogenic temperatures were subject to photodetachment at different photon energies and the resulting neutrals collected. Preliminary analysis of the decay in neutral production yields a radiative lifetime of approximately 15 seconds for the 3d94s2 2D3/2 excited state.
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| 26. |
- Chartkunchand, Kiattichart C., et al.
(författare)
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Radiative lifetimes of the bound excited states of Pt-
- 2016
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Ingår i: Physical Review A - Atomic, Molecular, and Optical Physics. - 1050-2947 .- 1094-1622. ; 94:3
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Tidskriftsartikel (refereegranskat)abstract
- © 2016 American Physical Society.The intrinsic radiative lifetimes of the 5d106sS1/22 and 5d96s2 D3/22 bound excited states in the platinum anion Pt- have been studied at cryogenic temperatures at the Double ElectroStatic Ion Ring Experiment (DESIREE) facility at Stockholm University. The intrinsic lifetime of the higher-lying 5d106s S1/22 state was measured to be 2.54±0.10s, while only a lifetime in the range of 50-200 ms could be estimated for the 5d96s2 D3/22 fine-structure level. The storage lifetime of the Pt- ion beam was measured to be a little over 15 min at a ring temperature of 13K. The present study reports the lifetime of an atomic negative ion in an excited bound state with an electron configuration different from that of the ground state.
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| 27. |
- Dongiovanni, P., et al.
(författare)
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Transmembrane 6 Superfamily Member 2 Gene Variant Disentangles Nonalcoholic Steatohepatitis From Cardiovascular Disease
- 2015
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Ingår i: Hepatology. - : Ovid Technologies (Wolters Kluwer Health). - 0270-9139 .- 1527-3350. ; 61:2, s. 506-514
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Tidskriftsartikel (refereegranskat)abstract
- Excess hepatic storage of triglycerides is considered a benign condition, but nonalcoholic steatohepatitis (NASH) may progress to fibrosis and promote atherosclerosis. Carriers of the TM6SF2 E167K variant have fatty liver as a result of reduced secretion of very-low-density lipoproteins (VLDLs). As a result, they have lower circulating lipids and reduced risk of myocardial infarction. In this study, we aimed to assess whether TM6SF2 E167K affects liver damage and cardiovascular outcomes in subjects at risk of NASH. Liver damage was evaluated in 1,201 patients who underwent liver biopsy for suspected NASH; 427 were evaluated for carotid atherosclerosis. Cardiovascular outcomes were assessed in 1,819 controls from the Swedish Obese Subjects (SOS) cohort. Presence of the inherited TM6SF2 E167K variant was determined by TaqMan assays. In the liver biopsy cohort, 188 subjects (13%) were carriers of the E167K variant. They had lower serum lipid levels than noncarriers (P<0.05), had more-severe steatosis, necroinflammation, ballooning, and fibrosis (P<0.05), and were more likely to have NASH (odds ratio [OR]: 1.84; 95% confidence interval [CI]: 1.23-2.79) and advanced fibrosis (OR, 2.08; 95% CI: 1.20-3.55), after adjustment for age, sex, body mass index, fasting hyperglycemia, and the I148M PNPLA3 risk variant. However, E167K carriers had lower risk of developing carotid plaques (OR, 0.49; 95% CI: 0.25-0.94). In the SOS cohort, E167K carriers had higher alanine aminotransferase ALT and lower lipid levels (P<0.05), as well as a lower incidence of cardiovascular events (hazard ratio: 0.61; 95% CI: 0.39-0.95). Conclusions: Carriers of the TM6SF2 E167K variant are more susceptible to progressive NASH, but are protected against cardiovascular disease. Our findings suggest that reduced ability to export VLDLs is deleterious for the liver. (Hepatology 2015;61:506-514)
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| 28. |
- Kamińska, Magdalena, et al.
(författare)
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Lifetime of the bound excited level in Ni
- 2016
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Ingår i: Physical Review A. - 1050-2947 .- 1094-1622. ; 93:1
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Tidskriftsartikel (refereegranskat)abstract
- The intrinsic lifetime of the upper level in the bound-bound 3d(9) 4s(2) D-2(3/2) -> 3d(9) 4s(2) D-2(5/2) radiative transition in Ni- was measured to be 15.1 +/- 0.4 s. The experiment was performed at cryogenic temperatures in one of the ion-beam storage rings of the Double ElectroStatic Ion Ring ExpEriment facility at Stockholm University. The storage lifetime of the Ni- ion beam was measured to be close to 5 min at a ring temperature of 13 K.
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| 29. |
- Kaminska, M, et al.
(författare)
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Storing keV negative ions for hours: Lifetime measurements in new time domains
- 2015
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Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 635
-
Konferensbidrag (refereegranskat)abstract
- We have used one of the cryogenic ion storage rings of DESIREE to measure the lifetime of the 2P o 1/2 level in the sulfur anion to be 503 ± 43 seconds. This is orders of magnitude longer than any previously measured lifetime in a negatively charged ion.
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| 30. |
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