| 1. |
- Munk, P., et al.
(författare)
-
Genomic analysis of sewage from 101 countries reveals global landscape of antimicrobial resistance
- 2022
-
Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 13:1
-
Tidskriftsartikel (refereegranskat)abstract
- Antimicrobial resistance (AMR) is a major threat to global health. Understanding the emergence, evolution, and transmission of individual antibiotic resistance genes (ARGs) is essential to develop sustainable strategies combatting this threat. Here, we use metagenomic sequencing to analyse ARGs in 757 sewage samples from 243 cities in 101 countries, collected from 2016 to 2019. We find regional patterns in resistomes, and these differ between subsets corresponding to drug classes and are partly driven by taxonomic variation. The genetic environments of 49 common ARGs are highly diverse, with most common ARGs carried by multiple distinct genomic contexts globally and sometimes on plasmids. Analysis of flanking sequence revealed ARG-specific patterns of dispersal limitation and global transmission. Our data furthermore suggest certain geographies are more prone to transmission events and should receive additional attention.
|
|
| 2. |
- Schiessling, Joachim, et al.
(författare)
-
Synchrotron radiation study of the electronic structure of multiwalled carbon nanotubes
- 2003
-
Ingår i: Journal of Physics. - : IOP Publishing. - 0953-8984 .- 1361-648X. ; 15:38, s. 6563-
-
Tidskriftsartikel (refereegranskat)abstract
- We present photoelectron (PE) and x-ray absorption spectra (XAS) of macroscopically aligned multiwalled carbon nanotubes. We identify the peaks in the valence PE spectra with regions of high density of states through comparison to calculations for graphite. Finally, we outline and illustrate a simple method for using XAS to determine the average alignment of a nanotube sample.
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
- Schiessling, J, et al.
(författare)
-
Bulk and surface charge states of K3C60
- 2005
-
Ingår i: Physical Review B (Condensed Matter and Materials Physics). - 1098-0121. ; 71:16
-
Tidskriftsartikel (refereegranskat)abstract
- We detect a significant angle-dependence in the core level and valence line shapes of photoelectron spectra of single crystal K3C60. This allows the identification of bulk and surface components in the data, and allows us to explain the anomalous line shapes observed for this system. The states near the Fermi level are associated with the bulk of the sample. There is strong evidence of an insulating surface layer, which we ascribe to intermolecular electron correlations. These results simplify the interpretation of previous, apparently conflicting observations.
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
|
|
| 11. |
- Schnadt, J, et al.
(författare)
-
Excited-state charge transfer dynamics in systems of aromatic adsorbates on TiO2 studied with resonant core techniques
- 2003
-
Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 119:23, s. 12462-12472
-
Tidskriftsartikel (refereegranskat)abstract
- Resonant core spectroscopies are applied to a study of the excited electron transfer dynamics on a low-femtosecond time scale in systems of aromatic molecules (isonicotinic acid and bi-isonicotinic acid) adsorbed on a rutile TiO2(110) semiconductor surface. Depending on which adsorbate state is excited, the electron is either localized on the adsorbate in an excitonic effect, or delocalizes rapidly into the substrate in less than 5 fs (3 fs) for isonicotinic acid (bi-isonicotinic acid). The results are obtained by the application of a variant of resonant photoemission spectroscopy. (C) 2003 American Institute of Physics.
|
|
| 12. |
|
|
| 13. |
- Alfredsson, Ylvi, et al.
(författare)
-
Electronic structure of a vapor-deposited metal-free phthalocyanine thin film
- 2005
-
Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 122:21
-
Tidskriftsartikel (refereegranskat)abstract
- The electronic structure of a vapor-sublimated thin film of metal-free phthalocyanine (H2Pc) is studied experimentally and theoretically. An atom-specific picture of the occupied and unoccupied electronic states is obtained using x-ray-absorption spectroscopy (XAS), core- and valence-level x-ray photoelectron spectroscopy (XPS), and density-functional theory (DFT) calculations. The DFT calculations allow for an identification of the contributions from individual nitrogen atoms to the experimental N1s XAS and valence XPS spectra. This comprehensive study of metal-free phthalocyanine is relevant for the application of such molecules in molecular electronics and provides a solid foundation for identifying modifications in the electronic structure induced by various substituent groups.
|
|
| 14. |
|
|
| 15. |
- Chao, Y, et al.
(författare)
-
Reactions and luminescence in passivated Si nanocrystallites induced by vacuum ultraviolet and soft-x-ray photons
- 2005
-
Ingår i: Applied Physics Reviews. - : AIP Publishing. - 1931-9401. ; 98:4
-
Tidskriftsartikel (refereegranskat)abstract
- Alkyl-modified silicon nanocrystallites are efficient fluorophores which are of interest for fundamental spectroscopic studies and as luminescent probes in biology because of their stability in aqueous media. In this work we have investigated these particles using scanning tunneling microscopy, synchrotron-radiation excited photoemission, and x-ray excited optical luminescence (XEOL). During the course of illumination with 145-eV photons we have monitored the evolution of the Si2p core level and, in samples which have suffered prolonged atmospheric exposure, observed in real time the growth of an extra Si2p component attributed to in situ photoinduced oxidation of the Si nanocrystallites. XEOL reveals that two emission bands are active upon soft-x-ray photon excitation and that photoluminescence intensity decreases with photon exposure, which is attributed to charge trapping within the film.
|
|
| 16. |
|
|
| 17. |
|
|
| 18. |
|
|
| 19. |
|
|
| 20. |
- Macovez, R., et al.
(författare)
-
Electronic surface reconstruction and correlation in the fcc and dimer phases of RbC60
- 2007
-
Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 75:19, s. 195424-
-
Tidskriftsartikel (refereegranskat)abstract
- A combined photoemission and x-ray absorption study of a RbC60 crystalline film is presented. We find evidence for an electronic charge reconstruction of the film surface in both the fcc and the dimer phases of RbC60. We confirm the previous conclusion on less crystalline films that the dimer phase is insulating. Several observations, such as the presence of molecular features in the photoemission spectra, indicate that at least partial electron localization occurs in the high-temperature fcc phase. In the fcc phase, the surface consists in a half-charge C60(111) plane and appears weakly metallic, as found for the bulk. In the dimer phase, the charge reconstruction simply implies the presence of neutral C60 in the surface layer. The identification of neutral molecules in the surface layer drastically improves the agreement between calculations of the electronic density of states and photoelectron spectra in both phases.
|
|
| 21. |
- Pichler, T, et al.
(författare)
-
Proof for trivalent Sc ions in Sc-2 @ C-84 from high-energy spectroscopy
- 2000
-
Ingår i: PHYSICAL REVIEW B. - : AMERICAN PHYSICAL SOC. - 0163-1829. ; 62:19, s. 13196-13201
-
Tidskriftsartikel (refereegranskat)abstract
- The electronic structure and the valency of the Sc ions in the endohedral dimetallofullerene Sc-2 @ C-84 with D-2d symmetry are probed using high-energy spectroscopy. Comparison of the Sc 2p --> 3d x-ray-absorption spectrum with calculated ionic multiplet
|
|
| 22. |
|
|
| 23. |
|
|
| 24. |
- Schiessling, J, et al.
(författare)
-
Insulating surface layer on single crystal K3C60
- 2004
-
Ingår i: European Physical Journal B. Condensed Matter and Complex Systems. - : Springer Science and Business Media LLC. - 1434-6028. ; 41:4, s. 435-438
-
Tidskriftsartikel (refereegranskat)abstract
- Using angle-dependent photoemission spectra of core and valence levels we show that metallic, single crystal K3C60 is terminated by an insulating or weakly-conducting surface layer. We attribute this to the effects of strong intermolecular correlations combined with the average surface charge state. Several controversies on the electronic structure are thereby resolved.
|
|
| 25. |
|
|
| 26. |
|
|
| 27. |
- Schiessling, J, et al.
(författare)
-
Polarization-dependent angular photoelectron distribution of solid C-60
- 2003
-
Ingår i: Physical Review B (Condensed Matter and Materials Physics). - 1098-0121 .- 1550-235X. ; 68:20
-
Tidskriftsartikel (refereegranskat)abstract
- We present angle- and polarization-dependent photoelectron spectra of solid C-60 recorded over a large range of emission angles. The bands derived from the three highest molecular orbitals are very similar in their angular distribution and show a strong dependence on both light polarization direction and sample orientation. We show that a molecular emission pattern modified by solid-state effects accounts for the observations.
|
|
| 28. |
- Siller, L., et al.
(författare)
-
Core and valence exciton formation in x-ray absorption, x-ray emission and x-ray excited optical luminescence from passivated Si nanocrystals at the Si L-2,L-3 edge
- 2009
-
Ingår i: Journal of Physics: Condensed Matter. - : IOP Publishing. - 1361-648X .- 0953-8984. ; 21:9
-
Tidskriftsartikel (refereegranskat)abstract
- Resonant inelastic x-ray scattering (RIXS), x-ray absorption spectroscopy and x-ray excited optical luminescence (XEOL) have been used to measure element specific filled and empty electronic states over the Si L-2,L-3 edge of passivated Si nanocrystals of narrow size distribution ( diameter 2.2 +/- 0.4 nm). These techniques have been employed to directly measure absorption and luminescence specific to the local Si nanocrystal core. Profound changes occur in the absorption spectrum of the nanocrystals compared with bulk Si, and new features are observed in the nanocrystal RIXS. Clear signatures of core and valence band exciton formation, promoted by the spatial confinement of electrons and holes within the nanocrystals, are observed, together with band narrowing due to quantum confinement. XEOL at 12 K shows an extremely sharp feature at the threshold of orange luminescence (i.e., at similar to 1.56 eV ( 792 nm)) which we attribute to recombination of valence excitons, providing a lower limit to the nanocrystal band gap.
|
|
| 29. |
|
|
