| 1. |
- Eklund, Gustav, et al.
(author)
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Final-state-resolved mutual neutralization of Na+ and D-
- 2021
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In: Physical Review A: covering atomic, molecular, and optical physics and quantum information. - : American Physical Society. - 2469-9926 .- 2469-9934. ; 103:3
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Journal article (peer-reviewed)abstract
- The present paper reports on a merged-beam experiment on mutual neutralization between Na+ and D-. For this experiment, we have used the DESIREE ion-beams storage-ring facility. The reaction products are detected using a position- and time-sensitive detector, which ideally allows for determination of the population of each individual quantum state in the final atomic systems. Here, the 4s, 3d, and 4p final states in Na are observed and in all cases the D atom is in its ground state 1s S-2. The respective branching fractions of the states populated in Na are determined by fitting results from a Monte Carlo simulation of the experiment to the measured data. The center-of-mass collision energy is controlled using a set of biased drift tubes, and the branching fractions are measured for energies between 80 meV and 393 meV. The resulting branching fractions are found to agree qualitatively with the only available theoretical calculations for this particular system, which are based on a multichannel Landau-Zener approach using dynamic couplings determined with a linear combination of atomic orbitals model.
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| 2. |
- Poline, Mathias, et al.
(author)
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Mutual neutralisation of O+ with O− : investigation of the role of metastable ions in a combined experimental and theoretical study
- 2021
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In: Physical Chemistry, Chemical Physics - PCCP. - : Royal Society of Chemistry (RSC). - 1463-9076 .- 1463-9084. ; 23:43, s. 24607-24616
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Journal article (peer-reviewed)abstract
- The mutual neutralisation of O+ with O− has been studied in a double ion-beam storage ring with combined merged-beams, imaging and timing techniques. Branching ratios were measured at the collision energies of 55, 75 and 170 (± 15) meV, and found to be in good agreement with previous single-pass merged-beams experimental results at 7 meV collision energy. Several previously unidentified spectral features were found to correspond to mutual neutralisation channels of the first metastable state of the cation (O+(2Do), τ ≈ 3.6 hours), while no contributions from the second metastable state (O+(2Po), τ ≈ 5 seconds) were observed. Theoretical calculations were performed using the multi-channel Landau–Zener model combined with the anion centered asymptotic method, and gave good agreement with several experimentally observed channels, but could not describe well observed contributions from the O+(2Do) metastable state as well as channels involving the O(3s 5So) state.
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| 3. |
- Boretzky, K., et al.
(author)
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NeuLAND: The high-resolution neutron time-of-flight spectrometer for R 3 B at FAIR
- 2021
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In: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - : Elsevier BV. - 0168-9002. ; 1014
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Journal article (peer-reviewed)abstract
- NeuLAND (New Large-Area Neutron Detector) is the next-generation neutron detector for the R3B (Reactions with Relativistic Radioactive Beams) experiment at FAIR (Facility for Antiproton and Ion Research). NeuLAND detects neutrons with energies from 100 to 1000 MeV, featuring a high detection efficiency, a high spatial and time resolution, and a large multi-neutron reconstruction efficiency. This is achieved by a highly granular design of organic scintillators: 3000 individual submodules with a size of 5 × 5 × 250 cm3 are arranged in 30 double planes with 100 submodules each, providing an active area of 250 × 250 cm2 and a total depth of 3 m. The spatial resolution due to the granularity together with a time resolution of σt≤ 150 ps ensures high-resolution capabilities. In conjunction with calorimetric properties, a multi-neutron reconstruction efficiency of 50% to 70% for four-neutron events will be achieved, depending on both the emission scenario and the boundary conditions allowed for the reconstruction method. We present in this paper the final design of the detector as well as results from test measurements and simulations on which this design is based.
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| 4. |
- Janson, Markus, et al.
(author)
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A wide-orbit giant planet in the high-mass b Centauri binary system
- 2021
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In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 600:7888
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Journal article (peer-reviewed)abstract
- Planet formation occurs around a wide range of stellar masses and stellar system architectures1. An improved understanding of the formation process can be achieved by studying it across the full parameter space, particularly towards the extremes. Earlier studies of planets in close-in orbits around high-mass stars have revealed an increase in giant planet frequency with increasing stellar mass2 until a turnover point at 1.9 solar masses (M⊙), above which the frequency rapidly decreases3. This could potentially imply that planet formation is impeded around more massive stars, and that giant planets around stars exceeding 3 M⊙ may be rare or non-existent. However, the methods used to detect planets in small orbits are insensitive to planets in wide orbits. Here we demonstrate the existence of a planet at 560 times the Sun–Earth distance from the 6- to 10-M⊙ binary b Centauri through direct imaging. The planet-to-star mass ratio of 0.10–0.17% is similar to the Jupiter–Sun ratio, but the separation of the detected planet is about 100 times wider than that of Jupiter. Our results show that planets can reside in much more massive stellar systems than what would be expected from extrapolation of previous results. The planet is unlikely to have formed in situ through the conventional core accretion mechanism4, but might have formed elsewhere and arrived to its present location through dynamical interactions, or might have formed via gravitational instability.
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| 5. |
- Jarochowska, Emilia, et al.
(author)
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Revision of thelodonts, acanthodians, conodonts, and the depositional environments in the Burgen outlier (Ludlow, Silurian) of Gotland, Sweden
- 2021
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In: GFF. - London : Taylor & Francis. - 1103-5897 .- 2000-0863. ; 143:2-3, s. 168-189
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Journal article (peer-reviewed)abstract
- Ludfordian strata exposed in the Burgen outlier in eastern Gotland, Sweden record a time of initial faunal recovery after a global environmental perturbation manifested in the Ludfordian Carbon Isotope Excursion (LCIE). Vertebrate microfossils in the collection of the late Lennart Jeppsson, hosted at the Swedish Museum of Natural History, hold the key to reconstruct the dynamics of faunal immigration and diversification during the decline of the LCIE, but the stratigraphic relationships of the strata have been debated. Historically, they had been placed in the Burgsvik Formation, which included the Burgsvik Sandstone and the Burgsvik Oolite members. We revise the fauna in the Jeppsson collection and characterize key outcrops of Burgen and Kapellet. The former Burgsvik Oolite Member is here revised as the Burgen Oolite Formation. In the Burgenoutlier, back-shoal facies of this formation are represented and their position in the Ozarkodina snajdri Biozone is supported. The shallow-marine position compared to the coeval strata in southern Gotland isreflected in the higher δ13C carb values, reaching +9.2‰. The back-shoal succession includes high-diversity metazoan reefs, which indicate a complete recovery of the carbonate producers as the LCIE declined. The impoverishment of conodonts associated with the LCIE in southern Gotland might be a product of facies preferences, as the diverse environments in the outlier yielded all 21 species known from the formation. Fish diversity also returned to normal levels as the LCIE declined, with a minimum of nine species. In line with previous reports, thelodont scales appear to dominate samples from the Burgen outlier.
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| 6. |
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| 7. |
- Nepper-Christensen, Lars, et al.
(author)
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Clinical outcome following late reperfusion with percutaneous coronary intervention in patients with ST-segment elevation myocardial infarction
- 2021
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In: European Heart Journal: Acute Cardiovascular Care. - : Oxford University Press (OUP). - 2048-8726 .- 2048-8734. ; 10:5, s. 523-531
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Journal article (peer-reviewed)abstract
- Background: Up to 40% of patients with ST-segment elevation myocardial infarction (STEMI) present later than 12 hours after symptom onset. However, data on clinical outcomes in STEMI patients treated with primary percutaneous coronary intervention (PCI) ≥12 hours after symptom onset are non-existent. We evaluated the association between primary PCI performed later than 12 hours after symptom onset and clinical outcomes in a large all-comer contemporary STEMI cohort. Methods: All STEMI patients treated with primary PCI in eastern Denmark from November 2009 to November 2016 were included and stratified by timing of the PCI. The combined clinical endpoint of all-cause mortality and hospitalisation for heart failure was identified from nationwide Danish registries. Results: We included 6674 patients: 6108 (92%) were treated <12 hours and 566 (8%) were treated ≥12 hours after symptom onset. During a median follow-up period of 3.8 (interquartile range 2.3-5.6) years, 30-day, one-year and long-term cumulative rates of the combined endpoint were 11%, 17% and 25% in patients treated <12 hours and 21%, 29% and 37% in patients treated ≥12 hours after symptom onset (P > 0.001 for all). Late presentation was independently associated with an increased risk of an adverse clinical outcome (hazard ratio 1.42, 95% confidence interval 1.22-1.66; P < 0.001). Conclusions: Increasing duration from symptom onset to primary PCI was associated with an increased risk of an adverse clinical outcome in patients with STEMI, especially when the delay exceeded 12 hours.
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| 8. |
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| 9. |
- Svensson, Anneli, 1972-, et al.
(author)
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Genetic Variant Score and Arrhythmogenic Right Ventricular Cardiomyopathy Phenotype in Plakophilin-2 Mutation Carriers
- 2021
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In: Cardiology. - : S. Karger. - 0008-6312 .- 1421-9751. ; 146:6, s. 763-771
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Journal article (peer-reviewed)abstract
- INTRODUCTION: Whether detailed genetic information contributes to risk stratification of patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) remains uncertain. Pathogenic genetic variants in some genes seem to carry a higher risk for arrhythmia and earlier disease onset than others, but comparisons between variants in the same gene have not been done. Combined Annotation Dependent Depletion (CADD) score is a bioinformatics tool that measures the pathogenicity of each genetic variant. We hypothesized that a higher CADD score is associated with arrhythmic events and earlier age at ARVC manifestations in individuals carrying pathogenic or likely pathogenic genetic variants in plakophilin-2 (PKP2).METHODS: CADD scores were calculated using the data from pooled Scandinavian and North American ARVC cohorts, and their association with cardiac events defined as ventricular tachycardia/ventricular fibrillation (VT/VF) or syncope and age at definite ARVC diagnosis were assessed.RESULTS: In total, 33 unique genetic variants were reported in 179 patients (90 males, 71 probands, 96 with definite ARVC diagnosis at a median age of 35 years). Cardiac events were reported in 76 individuals (43%), of whom 53 had sustained VT/VF (35%). The CADD score was neither associated with age at cardiac events (HR 1.002, 95% CI: 0.953-1.054, p = 0.933) nor with age at definite ARVC diagnosis (HR 0.992, 95% CI: 0.947-1.039, p = 0.731).CONCLUSION: No correlation was found between CADD scores and clinical manifestations of ARVC, indicating that the score has no additional risk stratification value among carriers of pathogenic or likely pathogenic PKP2 genetic variants.
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| 10. |
- Teague, Richard, et al.
(author)
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Discovery of Molecular-line Polarization in the Disk of TW Hya
- 2021
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In: Astrophysical Journal. - : American Astronomical Society. - 1538-4357 .- 0004-637X. ; 922:2
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Journal article (peer-reviewed)abstract
- We report observations of polarized line and continuum emission from the disk of TW Hya using the Atacama Large Millimeter/submillimeter Array. We target three emission lines, (CO)-C-12 (3-2), (CO)-C-13 (3-2), and CS (7-6), to search for linear polarization due to the Goldreich-Kylafis effect, while simultaneously tracing the continuum polarization morphology at 332 GHz (900 mu m), achieving a spatial resolution of 0.'' 5 (30 au). We detect linear polarization in the dust continuum emission; the polarization position angles show an azimuthal morphology, and the median polarization fraction is similar to 0.2%, comparable to previous, lower frequency observations. Adopting a "shift-and-stack" technique to boost the sensitivity of the data, combined with a linear combination of the Q and U components to account for their azimuthal dependence, we detect weak linear polarization of (CO)-C-12 and (CO)-C-13 line emission at a similar to 10 sigma and similar to 5 sigma significance, respectively. The polarization was detected in the line wings, reaching a peak polarization fraction of similar to 5% and similar to 3% for the two molecules between disk radii of 0.'' 5 and 1 ''. The sign of the polarization was found to flip from the blueshifted side of the emission to the redshifted side, suggesting a complex, asymmetric polarization morphology. Polarization is not robustly detected for the CS emission; however, a tentative signal, comparable in morphology to that found for the (CO)-C-12 and (CO)-C-13 emission, is found at a less than or similar to 3 sigma significance. We are able to reconstruct a polarization morphology, consistent with the azimuthally averaged profiles, under the assumption that this is also azimuthally symmetric, which can be compared with future higher-sensitivity observations.
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