| 1. |
- Chang, J., et al.
(författare)
-
Anisotropic breakdown of Fermi liquid quasiparticle excitations in overdoped La2-xSrxCuO4
- 2013
-
Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 4, s. 2559-
-
Tidskriftsartikel (refereegranskat)abstract
- High-temperature superconductivity emerges from an un-conventional metallic state. This has stimulated strong efforts to understand exactly how Fermi liquids breakdown and evolve into an un-conventional metal. A fundamental question is how Fermi liquid quasiparticle excitations break down in momentum space. Here we show, using angle-resolved photoemission spectroscopy, that the Fermi liquid quasiparticle excitations of the overdoped superconducting cuprate La1.77Sr0.23CuO4 is highly anisotropic in momentum space. The quasiparticle scattering and residue behave differently along the Fermi surface and hence the Kadowaki-Wood's relation is not obeyed. This kind of Fermi liquid breakdown may apply to a wide range of strongly correlated metal systems where spin fluctuations are present.
|
|
| 2. |
- Fatuzzo, C. G., et al.
(författare)
-
Nodal Landau Fermi-liquid quasiparticles in overdoped La1.77Sr0.23CuO4
- 2014
-
Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 89:20, s. 205104-
-
Tidskriftsartikel (refereegranskat)abstract
- Nodal angle-resolved photoemission spectra taken on overdoped La1.77Sr0.23CuO4 are presented and analyzed. It is proven that the low-energy excitations are true Landau Fermi-liquid quasiparticles. We show that momentum and energy distribution curves can be analyzed self-consistently without quantitative knowledge of the bare band dispersion. Finally, by imposing Kramers-Kronig consistency on the self-energy Sigma, insight into the quasiparticle residue is gained. We conclude by comparing our results to quasiparticle properties extracted from thermodynamic, magnetoresistance, and high-field quantum oscillation experiments on overdoped Tl2Ba2CuO6+delta.
|
|
| 3. |
- Horn, M. A., et al.
(författare)
-
Screening for X-linked adrenoleukodystrophy among adult men with Addison's disease
- 2013
-
Ingår i: Clinical Endocrinology. - : Wiley. - 0300-0664. ; 79:3, s. 316-320
-
Tidskriftsartikel (refereegranskat)abstract
- ObjectivesX-linked adrenoleukodystrophy is an important cause of Addison's disease in boys, but less is known about its contribution to Addison's disease in adult men. After surveying all known cases of X-linked adrenoleukodystrophy in Norway in a separate study, we aimed to look for any missed cases among the population of adult men with nonautoimmune Addison's disease. Study designAmong 153 adult men identified in a National Registry for Addison's Disease (75% of identified male cases of Addison's disease in Norway), those with negative indices for 21-hydroxylase autoantibodies were selected. Additionally, cases with low autoantibody indices (48-200) were selected. Sera from subjects included were analysed for levels of very long-chain fatty acids, which are diagnostic for X-linked adrenoleukodystrophy in men. ResultsEighteen subjects had negative indices and 17 had low indices for 21-hydroxylase autoantibodies. None of those with low indices and only one of those with negative indices were found to have X-linked adrenoleukodystrophy; this subject had already been diagnosed because of the neurological symptoms. Cases of Addison's disease proved to be caused by X-linked adrenoleukodystrophy constitute 15% of all adult male cases in Norway; the proportion among nonautoimmune cases was 15%. ConclusionsWe found X-linked adrenoleukodystrophy to be an uncommon cause of Addison's disease in adult men. However, this aetiological diagnosis has far-reaching consequences both for the patient and for his extended family. We therefore recommend that all adult men with nonautoimmune Addison's disease be analysed for levels of very long-chain fatty acids.
|
|
| 4. |
|
|
| 5. |
- Arnold, C. L., et al.
(författare)
-
Stabilized interferometric attosecond timing measurements
- 2013
-
Ingår i: CLEO : QELS_Fundamental Science, CLEO:QELS FS 2013 - QELS_Fundamental Science, CLEO:QELS FS 2013. - 9781557529725
-
Konferensbidrag (refereegranskat)abstract
- We perform interferometric attosecond timing measurements to study XUV photoionization in noble gases, to diagnose macroscopic phase-matching conditions in high-order harmonic generation, and to investigate single-photon double-ionization by detecting electron pairs in coincidence.
|
|
| 6. |
- Cereda, Maurizio, et al.
(författare)
-
Quantitative imaging of alveolar recruitment with hyperpolarized gas MRI during mechanical ventilation
- 2011
-
Ingår i: Journal of Applied Physiology. - : American Physiological Society. - 1522-1601 .- 8750-7587. ; 110:2, s. 499-511
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to assess the utility of He-3 MRI to noninvasively probe the effects of positive end-expiratory pressure (PEEP) maneuvers on alveolar recruitment and atelectasis buildup in mechanically ventilated animals. Sprague-Dawley rats (n = 13) were anesthetized, intubated, and ventilated in the supine position (He-4-to-O-2 ratio: 4:1; tidal volume: 10 ml/kg, 60 breaths/min, and inspiration-to-expiration ratio: 1:2). Recruitment maneuvers consisted of either a stepwise increase of PEEP to 9 cmH(2)O and back to zero end-expiratory pressure or alternating between these two PEEP levels. Diffusion MRI was performed to image He-3 apparent diffusion coefficient (ADC) maps in the middle coronal slices of lungs (n = 10). ADC was measured immediately before and after two recruitment maneuvers, which were separated from each other with a wait period (8-44 min). We detected a statistically significant decrease in mean ADC after each recruitment maneuver. The relative ADC change was -21.2 +/- 4.1 % after the first maneuver and -9.7 +/- 5.8 % after the second maneuver. A significant relative increase in mean ADC was observed over the wait period between the two recruitment maneuvers. The extent of this ADC buildup was time dependent, as it was significantly related to the duration of the wait period. The two postrecruitment ADC measurements were similar, suggesting that the lungs returned to the same state after the recruitment maneuvers were applied. No significant intrasubject differences in ADC were observed between the corresponding PEEP levels in two rats that underwent three repeat maneuvers. Airway pressure tracings were recorded in separate rats undergoing one PEEP maneuver (n = 3) and showed a significant relative difference in peak inspiratory pressure between pre- and poststates. These observations support the hypothesis of redistribution of alveolar gas due to recruitment of collapsed alveoli in presence of atelectasis, which was also supported by the decrease in peak inspiratory pressure after recruitment maneuvers.
|
|
| 7. |
- Freiburghaus, Catja, et al.
(författare)
-
Identification of ubiquitin in bovine milk and its growth inhibitory effects on human cancer cell lines.
- 2010
-
Ingår i: Journal of Dairy Science. - : American Dairy Science Association. - 1525-3198 .- 0022-0302. ; 93:8, s. 3442-3452
-
Tidskriftsartikel (refereegranskat)abstract
- Bovine milk is associated with improved health and reduced risk of several diseases, among them cancer. Milk is a complex mixture of known and unknown components. The components and the mechanisms that contribute to the cancer-preventive effects are largely unknown. We set out to find new peptides in milk and identified ubiquitin (Ub) using matrix-assisted laser desorption ionization-time of flight mass spectrometry and Western blot. Using quantitative Western blot, we estimated the Ub concentration to be about 0.003 micromol/L in milk. We then decided to investigate the effect of treating human colon cancer CaCo-2 cells with Ub, using higher concentrations than in milk. CaCo-2 cells treated with 0.02 to 2.0 micromol/L Ub showed significantly decreased proliferation compared with untreated control cells. A higher growth inhibitory effect than in CaCo-2 cells was found in the neuroblastoma cell line SH-SY5Y treated with 0.02 to 0.2 micromol/L Ub. A bromodeoxyuridine DNA flow cytometric method was used to study cell cycle kinetics in Ub-treated CaCo-2 cells. The data point toward a prolongation of the G(1) phase. The levels of several cell cycle regulatory proteins were affected. Our data point to Ub possibly being one of the components in milk reducing the risk of cancer.
|
|
| 8. |
- Gisselbrecht, Mathieu, et al.
(författare)
-
Charge migration and decay of doubly charged ammonia clusters
- 2012
-
Ingår i: Journal of Physics, Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 388:2, s. 022112-
-
Tidskriftsartikel (refereegranskat)abstract
- The photo-fragmentation of ammonia molecular clusters ionized with soft x-rays is studied for photon energies near the N-1s threshold. The fragmentation is studied with a 3D momentum mass spectrometer to access the energy and angular correlations between fragments. By choosing the cluster sizes below or above the critical size of stable dication, we investigate the coulomb explosion dynamics and the interplay between charge delocalization and mobility of molecules in the clusters.
|
|
| 9. |
|
|
| 10. |
|
|
