| 1. |
- Boschker, J. E., et al.
(författare)
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In-plane structural order of domain engineered La0.7Sr0.3MnO3 thin films
- 2013
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Ingår i: Philosophical Magazine. - : Informa UK Limited. - 1478-6435 .- 1478-6443. ; 93:13, s. 1549-1562
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Tidskriftsartikel (refereegranskat)abstract
- We present a detailed structural study of tensile-strained La0.7Sr0.3MnO3 thin films. We use the substrate miscut to control the number of rhombohedral variants in the films and study the in-plane order and structural distortions. Using high-resolution X-ray diffraction, we demonstrate that step-edge induced lattice modulations occur in 4-variant films, whereas periodic twinning is the dominant in-plane order for 2-variant films. We show that the in-plane twinning angle is almost completely relaxed. However, the relaxation of shear strain by the out-of-plane twinning angle and the monoclinic distortion is only partial. Furthermore, the film thickness dependence of the domain width reveals that domain formation is a universal mechanism for shear strain relaxation. Finally, we show that the structural response to the transition from the paramagnetic to the ferromagnetic phase of La0.7Sr0.3MnO3 at 345K is smaller in 4-variant films compared to 2-variant films.
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| 2. |
- Ejrnaes, K, et al.
(författare)
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Characteristics of Escherichia coli causing persistence or relapse of urinary tract infections Phylogenetic groups, virulence factors and biofilm formation
- 2011
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Ingår i: VIRULENCE. - 2150-5594. ; 2:6, s. 528-537
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Tidskriftsartikel (refereegranskat)abstract
- Abstract: Recurrent urinary tract infections (RUTIs) pose a major problem but little is known about characteristics of Escherichia coli associated with RUTI. This study includes E. coli from 155 women with community-acquired lower urinary tract infections (UTIs) randomized to one of three dosing regiments of pivmecillinam and aimed to identify associations between the presence of 29 virulence factor genes (VFGs), phylogenetic groups and biofilm formation and the course of infection during follow-up visits at 8-10 and 35-49 d post-inclusion, respectively. E. coli causing persistence or relapse were more often of phylogenetic group B2 and had a significantly higher aggregate VFG score than E. coli that were not detectable at follow-up. Specifically, these E. coli causing persistence or relapse were characterized by a higher prevalence of hemolysis and 12 VFGs (sfa/focDE, papAH, agn43, chuA, fyuA, iroN, kpsM II, kpsM II K2, cnf1, hlyD, malX and usp). KpsM II K2 and agn43a(CFT073) were independently associated with persistence or relapse. No specific combination of presence/absence of VFGs could serve as a marker to predict RUTI. Stratifying for VFGs, seven days of pivmecillinam treatment reduced the prevalence of persistence or relapse of UTI compared with three days. In vitro biofilm formation was not higher among E. coli causing persistence or relapse. The presence of agn43a(CFT073) or agn43b(CFT073) was associated with biofilm forming capacity. In conclusion, our results show potential targets for prevention and treatment of persistence/relapse of UTI and potential markers for selecting treatment lengths and warrant studies of these and new VFGs.
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| 3. |
- Monsen, A. F., et al.
(författare)
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Surface stoichiometry of La0.7Sr0.3MnO3 during in vacuo preparation; A synchrotron photoemission study
- 2012
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Ingår i: Surface Science. - : Elsevier BV. - 0039-6028. ; 606:17-18, s. 1360-1366
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Tidskriftsartikel (refereegranskat)abstract
- We present a study of the surface stoichiometry and contamination of La0.7Sr0.3MnO3 thin films following exposure to air and subsequent in vacuo preparation. Samples were studied using both soft X-ray synchrotron photoemission (hv = 150 to 350 eV) and traditional Mg-K alpha XPS (hv = 1253.6 eV) whilst annealing incrementally to approximate to 510 degrees C in low pressures of O-2. In all cases, a Mn depleted and Sr rich surface oxide layer is observed, it is of reduced crystalline quality and is charge depleted. This surface layer is weakly affected by subsequent annealing, and is partially reversed by annealing in higher O-2 pressure. Surface carbon contamination is incrementally removed by annealing at increased temperatures, and at 270 degrees C, it is reduced to approximate to 0.4% of the topmost unit cell. The modification of the surface stoichiometry and electronic properties is consistent with the reported loss of magnetic properties in thin LSMO films. (C) 2012 Elsevier B.V. All rights reserved.
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