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- Duda, L.-C., et al.
(författare)
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Resonant inelastic X-ray scattering at the NiO O K-resonance: non-local charge-transfer and double singlet excitations
- 2007
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Ingår i: MAX-lab. - Lund : MAX-lab. ; , s. 270-271
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- NiO is one of the prototypical compounds that has highlighted the importance of correlation effects in transition metal oxides. Core level spectroscopies bear evidence for the highly correlated nature of low energy excitations. For instance, the asymmetry of the Ni2p-line shape has been attributed to non-local charge transfer excitations and multi-site cluster calculations show that solidstate effects generally are appreciable for correlated materials, such as cuprates and high Tc-compounds.....
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| 4. |
- Duda, Laurent, et al.
(författare)
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Resonant Inelastic X-Ray Scattering at the Oxygen K Resonance of NiO: Nonlocal Charge Transfer and Double-Singlet Excitations
- 2006
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 96:067402
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Tidskriftsartikel (refereegranskat)abstract
- We report high-resolution polarization-dependent resonant inelastic x-ray scattering (RIXS) at the O K resonance of NiO showing a rich excitation spectrum. We perform multisite Ni6O19 cluster model calculations, revealing that solid state effects are substantial. We identify a nonlocal charge transfer excitation at 4–5 eV and double-singlet creation at 1.75 eV, both exhibiting significant scattering geometry dependence. Apart from an intense band of local charge transfer excitations (above 5 eV) also dd excitations at 1 eV are observed. Finally, we point out that O K RIXS of correlated metal oxides allows a quantitative and consistent determination of the charge transfer energy and the Hund coupling energy JH.
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| 5. |
- Frisk, Margot L. A., et al.
(författare)
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Increased occurrence of respiratory symptoms is associated with indoor climate risk indicators : a cross-sectional study in a Swedish population
- 2007
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Ingår i: Respiratory Medicine. - : Elsevier BV. - 0954-6111 .- 1532-3064. ; 101:9, s. 2031-2035
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Tidskriftsartikel (refereegranskat)abstract
- A basic assumption was that exposure to the indoor environment would increase the manifestation of respiratory symptoms in predisposed individuals. The aim was to investigate the proportion of perceived respiratory symptoms attributed to specific environmental exposures, and associations related to indoor climate risk indicators, i.e. occurrence of damp or mould, insufficient ventilation and condensation on windows.MethodA questionnaire was mailed to a random sample of 8008 individuals, stratified for gender and age. The response rate was 84% (n=6732). Established criteria for current asthma were used to classify subjects into three subgroups: asthmatics, healthy and symptomatics (but without current asthma).ResultsThe proportion of symptoms attributed to specific environmental exposures increased in the total sample and in the three subgroups when indoor climate risk indicators, particularly damp or mould, were reported. Generally, the lowest proportions were found for healthy and the highest for asthmatics. Univariate analyses presented as relative risks (RR) (95% CI) showed significantly increased risks for perceived overall influence on airways for all groups, with RR ranging from 4.3 to 6.8. Although respiratory symptoms attributed to dust, environmental tobacco smoke (ETS) and strong scents increased when risk indicators were reported, RR were generally lower in all groups.ConclusionThe high frequency of respiratory symptoms among asthmatics increased when occurrences of risk indicators were reported. Similarly, increased symptoms were found for healthy indicating that indoor climate risk indicators may affect both healthy and unhealthy individuals.
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| 6. |
- Fryxelius, J., et al.
(författare)
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Synthesis and redox properties of a meso-tris(4-nitrophenyl) corrolato Mn(III) complex
- 2005
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Ingår i: Journal of Porphyrins and Phthalocyanines. - 1088-4246 .- 1099-1409. ; 9:6, s. 379-386
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Tidskriftsartikel (refereegranskat)abstract
- The Mn complexated corrole [T(4-NO2P)Corr]Mn(py) (3) has been prepared (py = pyridine) where [T(4-NO2P)Corr] is the trianion of the electron-poor 5,10,15-tris(4-nitrophenyl)-corrole (1). The preparation of 3 includes a new synthetic method to form the corrole ligand 1 in a two-step synthesis. The Mn(III) complex gives a parallel mode EPR signal centered around g = 8.2 with six distinct hyperfine lines (A(parallel to) = 139 x 10(-4) cm(-1)). Electrochemically 3 undergoes one reversible oxidation (E-1/2 = 0.12 V vs Fc) and two reversible reductions (E-1/2 = -1.45, -1.61 V). The oxidation is metal-centered and the product has been characterized by EPR spectroscopy as an S = 3/2 Mn(IV) species with no indication for oxidation of the macrocycle. The reductions of complex 3 are ligand based, and at the potential of the second reduction step a stable nitrogen centered radical with g = 2.0055 is generated. Chemical oxidation of 3 by iodosobenzene yields a Mn(IV) complex and epoxidation of cis-stilbene is not catalyzed by the Mn complex.
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| 8. |
- Jansson, Kjell, 1958-, et al.
(författare)
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Normal values and differences between intraperitoneal and subcutaneous microdialysis in patients after non‐complicated gastrointestinal surgery
- 2005
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Ingår i: Scandinavian Journal of Clinical and Laboratory Investigation. - : Informa UK Limited. - 0036-5513 .- 1502-7686. ; 65:4, s. 273-282
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Tidskriftsartikel (refereegranskat)abstract
- Objective. Visceral ischemia is an early event in the development of shock and organ failure. Microdialysis has been presented as a promising method for detection of visceral hypoxia and ischemia. The aim of this study was to investigate differences in the metabolic response measured by microdialysis between intraperitoneal and subcutaneous locations and to estimate normal values of lactate/pyruvate ratio, glucose and glycerol. Material and methods. Intraperitoneal and subcutaneous metabolic responses were compared regarding lacate/pyruvate ratio, glucose and glycerol, during 45 postoperative hours in 33 patients undergoing various non‐complicated elective major gastrointestinal surgery. Results. Intraperitoneal lactate/pyruvate ratio started around 15 and decreased over time, while subcutaneous levels were stable around 9. Glucose levels were higher intraperitoneally and increased rapidly during the first 9 h to 8.6 mM, while the subcutaneous levels increased during 21 h to 7.5 mM. Intraperitoneal glycerol levels were stable around 100 µM, while subcutaneous values started around 230 µM and then increased. Conclusions. In a non‐complicated postoperative course the lactate/pyruvate ratio and glucose levels are higher intraperitoneally, suggesting a higher postoperative intraperitoneal metabolism. Glycerol levels are higher and increase subcutaneously, suggesting increased postoperative energy demand, particularly in the visceral organs, as being responsible for the lipolysis seen in the subcutaneous tissue.
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| 9. |
- Josefson, Anna, et al.
(författare)
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Nickel allergy as risk factor for hand eczema : a population-based study
- 2009
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Ingår i: British Journal of Dermatology. - : Oxford University Press (OUP). - 0007-0963 .- 1365-2133. ; 160:4, s. 828-834
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: In population-based studies using self-reported nickel allergy, a hand eczema prevalence of 30-43% has been reported in individuals with nickel allergy. In a previous Swedish study, 958 schoolgirls were patch tested for nickel. In a questionnaire follow up 20 years later no association was found between nickel allergy and hand eczema. OBJECTIVES: To investigate further the relation between nickel allergy and hand eczema. METHODS: Three hundred and sixty-nine women, still living in the same geographical area, now aged 30-40 years, were patch tested and clinically investigated regarding hand eczema. RESULTS: Patch testing showed 30.1% nickel-positive individuals. The adjusted prevalence proportion ratio (PPR) for hand eczema after age 15 years in relation to nickel patch test results was 1.03 (95% confidence interval, CI 0.71-1.50). A history of childhood eczema was reported by 35.9%, and the PPR for hand eczema in relation to childhood eczema was 3.68 (95% CI 2.45-5.54). When analysing the relation separately in women with and without a history of childhood eczema a statistical interaction was found. The hand eczema risk was doubled in nickel-positive women without a history of childhood eczema, with a PPR of 2.23 (95% CI 1.10-4.49) for hand eczema after age 15 years. CONCLUSIONS: A doubled risk for hand eczema was found in nickel-positive women without a history of childhood eczema. When analysing all participants, there was no statistically significant difference between nickel-positive and nickel-negative women regarding occurrence of hand eczema. The most important risk factor for hand eczema was childhood eczema. The risk for hand eczema in nickel-positive women may previously have been overestimated.
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| 10. |
- Mattesini, Maurizio, et al.
(författare)
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Elastic properties and electrostructural correlations in ternary scandium-based cubic inverse perovskites : A first-principles study
- 2009
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 79, s. 125122-
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Tidskriftsartikel (refereegranskat)abstract
- Wehave performed ab initio calculations for the cubic inverse-perovskite Sc3EN(E=Al,Ga,In) systems to study their electronic band-structures and elastic properties.In this study, we used the accurate augmented plane waveplus local orbital method to find the equilibrium structural parametersand to compute the full elastic tensors. The obtained single-crystalelastic constants were used to quantify the stiffness of theSc-based ternary nitrides and to appraise their mechanical stability. Thesite-projected density of states, Fermi surfaces, and the charge-density plotshave also been used to analyze the chemical bonding betweenthe Sc6N cluster and the surrounding metallic lattice of eitherAl, Ga, or In atoms. Our calculations show that Sc3GaNhas the largest covalent Sc-N bonding-type character with the highestYoung, shear, and bulk moduli. Compared with the other twoisoelectronic systems, it also behaves as the most brittle materialwith a relatively large elastic anisotropy.
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