41 research outputs found
A Spin-Resolved Photoemission Study of Photohole Lifetimes in Ferromagnetic Gadolinium
High resolution spin-resolved photoemission is used to probe the properties
of a Gd(0001) surface state. The state shows both a spin-mixing behavior
reflecting the exchange of magnons with the local moments and a reduction of
the exchange splitting with increasing temperature. The surface state
polarization at low T suggests that the surface layer has an enhanced Tc of
365K or greater. Measurements of the photoemission linewidths show that at low
temperatures, the lifetime of a majority spin photohole is predominantly
limited by electron-phonon scattering and that of a minority spin photohole by
electron-magnon scattering. Since similar behavior may be expected for bulk
states close to the Fermi level, the transport properties of this material will
also be determined by different decay mechanisms in the two channels
Extrinsic Magnetotransport Phenomena in Ferromagnetic Oxides
This review is focused on extrinsic magnetotransport effects in ferromagnetic
oxides. It consists of two parts; the second part is devoted to an overview of
experimental data and theoretical models for extrinsic magnetotransport
phenomena. Here a critical discussion of domain-wall scattering is given.
Results on surfacial and interfacial magnetism in oxides are presented.
Spin-polarized tunnelling in ferromagnetic junctions is reviewed and
grain-boundary magnetoresistance is interpreted within a model of
spin-polarized tunnelling through natural oxide barriers. The situation in
ferromagnetic oxides is compared with data and models for conventional
ferromagnets. The first part of the review summarizes basic material
properties, especially data on the spin-polarization and evidence for
half-metallicity. Furthermore, intrinsic conduction mechanisms are discussed.
An outlook on the further development of oxide spin-electronics concludes this
review.Comment: 133 pages, 47 figures, submitted to Rep. Prog. Phy
The clinical relevance of oliguria in the critically ill patient : Analysis of a large observational database
Funding Information: Marc Leone reports receiving consulting fees from Amomed and Aguettant; lecture fees from MSD, Pfizer, Octapharma, 3 M, Aspen, Orion; travel support from LFB; and grant support from PHRC IR and his institution. JLV is the Editor-in-Chief of Critical Care. The other authors declare that they have no relevant financial interests. Publisher Copyright: © 2020 The Author(s). Copyright: Copyright 2020 Elsevier B.V., All rights reserved.Background: Urine output is widely used as one of the criteria for the diagnosis and staging of acute renal failure, but few studies have specifically assessed the role of oliguria as a marker of acute renal failure or outcomes in general intensive care unit (ICU) patients. Using a large multinational database, we therefore evaluated the occurrence of oliguria (defined as a urine output 16 years) patients in the ICON audit who had a urine output measurement on the day of admission were included. To investigate the association between oliguria and mortality, we used a multilevel analysis. Results: Of the 8292 patients included, 2050 (24.7%) were oliguric during the first 24 h of admission. Patients with oliguria on admission who had at least one additional 24-h urine output recorded during their ICU stay (n = 1349) were divided into three groups: transient - oliguria resolved within 48 h after the admission day (n = 390 [28.9%]), prolonged - oliguria resolved > 48 h after the admission day (n = 141 [10.5%]), and permanent - oliguria persisting for the whole ICU stay or again present at the end of the ICU stay (n = 818 [60.6%]). ICU and hospital mortality rates were higher in patients with oliguria than in those without, except for patients with transient oliguria who had significantly lower mortality rates than non-oliguric patients. In multilevel analysis, the need for RRT was associated with a significantly higher risk of death (OR = 1.51 [95% CI 1.19-1.91], p = 0.001), but the presence of oliguria on admission was not (OR = 1.14 [95% CI 0.97-1.34], p = 0.103). Conclusions: Oliguria is common in ICU patients and may have a relatively benign nature if only transient. The duration of oliguria and need for RRT are associated with worse outcome.publishersversionPeer reviewe
Elemental composition and nutritional characteristics of Cucurbita pepo subsp. Pepo seeds, oil cake and pumpkin oil
The objectives of the present study were to investigate multi-elemental and nutritional characteristics of dry pumpkin seeds, oil cake and pumpkin oil from different cultivars of oil seed pumpkin (Cucurbita pepo subsp. pepo var. styriaca, Cucurbitaceae). Two traditional oil seed pumpkin cultivars (Slovenska golica, Gleisdorfer Ölkürbis) and three hybrid cultivars (GL Maximal, GL Rustical, GL Opal) were studied. Dry pumpkin seeds were processed in an industrial scale oil mill into pumpkin seed oils whereby leaving oil cake as a by-product. Multi-elemental composition, dry matter, crude proteins and fats were analysed in pumpkin seeds and oil cake from all cultivars. A total of fourteen elements (P, K, Mg, S, Na, Ca, Fe, Zn, Mn, Cu, Mo, Cr, Co, V) were determined. Crude proteins in pumpkin seeds and oil cake ranged within 38.3-39.5% and 65.3-68.9%, while crude fats made up 47.1-49.8% and 8.7-10.3%, respectively. The highest protein content in seeds was found for GL Maximal, and in oil cake for GL Opal. Content of most elements in oil cake was twice as high as in seeds. The oil yield when processing pumpkin seeds into pumpkin oil was 39.7-41.5%. The highest relative fatty acid content in pumpkin oil was achieved by linoleic (C18:2; 46.1%), followed by oleic (C18:1; 34.2%) and stearic acid (C16:0; 12.3%). Differences in fatty acid oil composition were observed. Traditional cultivars had a higher content of oleic and lower content of linoleic acid than hybrid cultivars. Among all the cultivars, Gleisdorfer Ölkürbis had the highest oleic acid content, while GL Maximal was the richest in linoleic acid. The content of the analysed compounds in oil cakes suggest that these can be a valuable source of protein and minerals for the food processing industry
Spin-resolved photoelectron spectroscopy on cuprate systems
We review the basic electronic structure of cuprate systems, and discuss the importance of strong electron correlation effects. Using resonant photoelectron spectroscopy it is demonstrated that the undoped cuprates belong to the class of charge-transfer insulators. As a consequence, the first ionization states are likely to consist of bound states with a compensated local spin structure rather than the usual high spin states expected from Hund's first rule. Using spin-resolved resonant photoemission with circularly-polarized light, we are able to unravel the different spin states of the valence band spectrum of the undoped cuprates and show that the top of the band is of pure singlet character, which provides strong support for the existence and stability of Zhang-Rice singlets in high-T-C superconductors. (C) 2001 Elsevier Science B.V. All rights reserved