| 1. |
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| 2. |
- Dunham, I, et al.
(author)
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The DNA sequence of human chromosome 22
- 1999
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In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 402:6761, s. 489-495
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Journal article (peer-reviewed)
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| 3. |
- Küspert, Julia, et al.
(author)
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Pseudogap suppression by competition with superconductivity in La-based cuprates
- 2022
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In: Physical Review Research. - 2643-1564. ; 4:4
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Journal article (peer-reviewed)abstract
- We carried out a comprehensive high-resolution angle-resolved photoemission spectroscopy (ARPES) study of the pseudogap interplay with superconductivity in La-based cuprates. The three systems La2-xSrxCuO4, La1.6-xNd0.4SrxCuO4, and La1.8-xEu0.2SrxCuO4 display slightly different pseudogap critical points in the temperature versus doping phase diagram. We studied the pseudogap evolution into the superconducting state for doping concentrations just below the critical point. In this setting, near optimal doping for superconductivity and in the presence of the weakest possible pseudogap, we uncover how the pseudogap is partially suppressed inside the superconducting state. This conclusion is based on the direct observation of a reduced pseudogap energy scale and re-emergence of spectral weight suppressed by the pseudogap. Altogether these observations suggest that the pseudogap phenomenon in La-based cuprates is in competition with superconductivity for antinodal spectral weight.
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| 4. |
- Güttler, M., et al.
(author)
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Divalent EuRh 2 Si 2 as a reference for the Luttinger theorem and antiferromagnetism in trivalent heavy-fermion YbRh 2 Si 2
- 2019
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In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 10:1
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Journal article (peer-reviewed)abstract
- Application of the Luttinger theorem to the Kondo lattice YbRh 2 Si 2 suggests that its large 4f-derived Fermi surface (FS) in the paramagnetic (PM) regime should be similar in shape and volume to that of the divalent local-moment antiferromagnet (AFM) EuRh 2 Si 2 in its PM regime. Here we show by angle-resolved photoemission spectroscopy that paramagnetic EuRh 2 Si 2 has a large FS essentially similar to the one seen in YbRh 2 Si 2 down to 1 K. In EuRh 2 Si 2 the onset of AFM order below 24.5 K induces an extensive fragmentation of the FS due to Brillouin zone folding, intersection and resulting hybridization of the Fermi-surface sheets. Our results on EuRh 2 Si 2 indicate that the formation of the AFM state in YbRh 2 Si 2 is very likely also connected with similar changes in the FS, which have to be taken into account in the controversial analysis and discussion of anomalies observed at the quantum critical point in this system.
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| 5. |
- Sutter, D., et al.
(author)
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Hallmarks of Hunds coupling in the Mott insulator Ca2RuO4
- 2017
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In: Nature Communications. - : NATURE PUBLISHING GROUP. - 2041-1723. ; 8
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Journal article (peer-reviewed)abstract
- A paradigmatic case of multi-band Mott physics including spin-orbit and Hund's coupling is realized in Ca2RuO4. Progress in understanding the nature of this Mott insulating phase has been impeded by the lack of knowledge about the low-energy electronic structure. Here we provide-using angle-resolved photoemission electron spectroscopy-the band structure of the paramagnetic insulating phase of Ca2RuO4 and show how it features several distinct energy scales. Comparison to a simple analysis of atomic multiplets provides a quantitative estimate of the Hund's coupling J = 0.4 eV. Furthermore, the experimental spectra are in good agreement with electronic structure calculations performed with Dynamical Mean-Field Theory. The crystal field stabilization of the d(xy) orbital due to c-axis contraction is shown to be essential to explain the insulating phase. These results underscore the importance of multi-band physics, Coulomb interaction and Hund's coupling that together generate the Mott insulating state of Ca2RuO4.
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| 6. |
- Matt, C. E., et al.
(author)
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Electron scattering, charge order, and pseudogap physics in La1.6-xNd0.4SrxCuO4 : An angle-resolved photoemission spectroscopy study
- 2015
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In: Physical Review B. Condensed Matter and Materials Physics. - : American Physical Society. - 1098-0121 .- 1550-235X. ; 92:13
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Journal article (peer-reviewed)abstract
- We report an angle-resolved photoemission study of the charge stripe ordered La1.6-xNd0.4SrxCuO4 (Nd-LSCO) system. A comparative and quantitative line-shape analysis is presented as the system evolves from the overdoped regime into the charge ordered phase. On the overdoped side (x = 0.20), a normal-state antinodal spectral gap opens upon cooling below 80 K. In this process, spectral weight is preserved but redistributed to larger energies. A correlation between this spectral gap and electron scattering is found. A different line shape is observed in the antinodal region of charge ordered Nd-LSCO x = 1/8. Significant low-energy spectral weight appears to be lost. These observations are discussed in terms of spectral-weight redistribution and gapping originating from charge stripe ordering.
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| 7. |
- Horio, M., et al.
(author)
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Electronic reconstruction forming a C-2-symmetric Dirac semimetal in Ca3Ru2O7
- 2021
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In: npj Quantum Materials. - : Springer Science and Business Media LLC. - 2397-4648. ; 6:1
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Journal article (peer-reviewed)abstract
- Electronic band structures in solids stem from a periodic potential reflecting the structure of either the crystal lattice or electronic order. In the stoichiometric ruthenate Ca3Ru2O7, numerous Fermi surface-sensitive probes indicate a low-temperature electronic reconstruction. Yet, the causality and the reconstructed band structure remain unsolved. Here, we show by angle-resolved photoemission spectroscopy, how in Ca3Ru2O7 a C-2-symmetric massive Dirac semimetal is realized through a Brillouin-zone preserving electronic reconstruction. This Dirac semimetal emerges in a two-stage transition upon cooling. The Dirac point and band velocities are consistent with constraints set by quantum oscillation, thermodynamic, and transport experiments, suggesting that the complete Fermi surface is resolved. The reconstructed structure-incompatible with translational-symmetry-breaking density waves-serves as an important test for band structure calculations of correlated electron systems.
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| 8. |
- Horio, M., et al.
(author)
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Oxide Fermi liquid universality revealed by electron spectroscopy
- 2020
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In: Physical Review B. - 2469-9969 .- 2469-9950. ; 102:24
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Journal article (peer-reviewed)abstract
- We present a combined soft x-ray and high-resolution vacuum-ultraviolet angle-resolved photoemission spectroscopy study of the electron-overdoped cuprate Pr1.3-xLa0.7CexCuO4 (PLCCO). Demonstration of its highly two-dimensional band structure enabled precise determination of the in-plane self-energy dominated by electron-electron scattering. Through analysis of this self-energy and the Fermi liquid cut-off energy scale, we find-in contrast to hole-doped cuprates-a momentum isotropic and comparatively weak electron correlation in PLCCO. Yet, the self-energies extracted from multiple oxide systems combine to demonstrate a logarithmic divergent relation between the quasiparticle scattering rate and mass. This constitutes a spectroscopic version of the Kadowaki-Woods relation with an important merit-the demonstration of Fermi liquid quasiparticle lifetime and mass being set by a single energy scale.
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| 9. |
- Horio, M., et al.
(author)
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Two-dimensional type-II Dirac fermions in layered oxides
- 2018
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In: Nature Communications. - : NATURE PUBLISHING GROUP. - 2041-1723. ; 9
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Journal article (peer-reviewed)abstract
- Relativistic massless Dirac fermions can be probed with high-energy physics experiments, but appear also as low-energy quasi-particle excitations in electronic band structures. In condensed matter systems, their massless nature can be protected by crystal symmetries. Classification of such symmetry-protected relativistic band degeneracies has been fruitful, although many of the predicted quasi-particles still await their experimental discovery. Here we reveal, using angle-resolved photoemission spectroscopy, the existence of two-dimensional type-II Dirac fermions in the high-temperature superconductor La1.77Sr0.23CuO4. The Dirac point, constituting the crossing of d(x2-y2) and d(z2) bands, is found approximately one electronvolt below the Fermi level (E-F) and is protected by mirror symmetry. If spin-orbit coupling is considered, the Dirac point degeneracy is lifted and the bands acquire a topologically non-trivial character. In certain nickelate systems, band structure calculations suggest that the same type-II Dirac fermions can be realised near EF.
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| 10. |
- Kramer, K. P., et al.
(author)
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Band structure of overdoped cuprate superconductors: Density functional theory matching experiments
- 2019
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In: Physical Review B. - 2469-9969 .- 2469-9950. ; 99:22
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Journal article (peer-reviewed)abstract
- A comprehensive angle-resolved photoemission spectroscopy study of the band structure in singlelayer cuprates is presented with the aim of uncovering universal trends across different materials. Five different hole-and electron-overdoped cuprate superconductors (La1.59Eu0.2Sr0.21CuO4, La1.77Sr0.23CuO4, Bi1.74Pb0.38Sr1.88CuO6+delta, Tl2Ba2CuO6+delta, and Pr1.15La0.7Ce0.15CuO4) have been studied with special focus on the bands with a predominately d-orbital character. Using a light polarization analysis, the e(g) and t(2g) bands are identified across these materials. A clear correlation between the d(3z2-r2) band energy and the apical oxygen distance d(A) is demonstrated. Moreover, the compound dependence of the d(x2-y2) band bottom and the t(2g) band top is revealed. A direct comparison to density functional theory (DFT) calculations employing hybrid exchange-correlation functionals demonstrates excellent agreement. We thus conclude that the DFT methodology can be used to describe the global band structure of overdoped single-layer cuprates on both the hole-and electron-doped side.
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| 11. |
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| 12. |
- Razzoli, E., et al.
(author)
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Rotation symmetry breaking in La2-xSrxCuO4 revealed by angle-resolved photoemission spectroscopy
- 2017
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In: Physical Review B. - : American Physical Society. - 2469-9950 .- 2469-9969. ; 95:22
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Journal article (peer-reviewed)abstract
- Using angle-resolved photoemission spectroscopy it is revealed that in the vicinity of optimal doping the electronic structure of La2-x SrxCuO4 cuprate undergoes an electronic reconstruction associated with a wave vector q(a) = (pi, 0). The reconstructed Fermi surface and folded band are distinct to the shadow bands observed in BSCCO cuprates and in underdoped La2-xSrxCuO4 with x <= 0.12, which shift the primary band along the zone diagonal direction. Furthermore, the folded bands appear only with q(a) = (pi, 0) vector, but not with q(b) = (0, pi). We demonstrate that the absence of q(b) reconstruction is not due to thematrix-element effects in the photoemission process, which indicates the fourfold symmetry is broken in the system.
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| 13. |
- Schild, R., et al.
(author)
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Disparities in treatment and outcome of kidney replacement therapy in children with comorbidities: an ESPN/ERA Registry study
- 2023
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In: Clinical Kidney Journal. - : Oxford University Press (OUP). - 2048-8505 .- 2048-8513. ; 16:4, s. 745-755
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Journal article (peer-reviewed)abstract
- Background Data on comorbidities in children on kidney replacement therapy (KRT) are scarce. Considering their high relevance for prognosis and treatment, this study aims to analyse the prevalence and implications of comorbidities in European children on KRT. Methods We included data from patients <20 years of age when commencing KRT from 2007 to 2017 from 22 European countries within the European Society of Paediatric Nephrology/European Renal Association Registry. Differences between patients with and without comorbidities in access to kidney transplantation (KT) and patient and graft survival were estimated using Cox regression. Results Comorbidities were present in 33% of the 4127 children commencing KRT and the prevalence has steadily increased by 5% annually since 2007. Comorbidities were most frequent in high-income countries (43% versus 24% in low-income countries and 33% in middle-income countries). Patients with comorbidities had a lower access to transplantation {adjusted hazard ratio [aHR] 0.67 [95% confidence interval (CI) 0.61-0.74]} and a higher risk of death [aHR 1.79 (95% CI 1.38-2.32)]. The increased mortality was only seen in dialysis patients [aHR 1.60 (95% CI 1.21-2.13)], and not after KT. For both outcomes, the impact of comorbidities was stronger in low-income countries. Graft survival was not affected by the presence of comorbidities [aHR for 5-year graft failure 1.18 (95% CI 0.84-1.65)]. Conclusions Comorbidities have become more frequent in children on KRT and reduce their access to transplantation and survival, especially when remaining on dialysis. KT should be considered as an option in all paediatric KRT patients and efforts should be made to identify modifiable barriers to KT for children with comorbidities. Lay Summary Kidney transplantation (KT) is considered the optimal treatment for children who suffer from permanent kidney failure, because it leads to a lower mortality and higher quality of life compared with dialysis. Children on dialysis frequently suffer from diseases of other organs (comorbidities) that can directly lower their life expectancy and could potentially represent a barrier for transplantation, posing an additional disease burden for these children. In this study we looked at data from a large multinational registry for children with kidney failure who require kidney replacement. Using these data, we studied whether these children suffered from comorbidities and whether these impact their life expectancy or their access to KT. We found that more and more children with kidney failure suffer from comorbidities when starting kidney replacement therapy. We also found that these children have a lower access to KT and a higher mortality on dialysis compared with children without comorbidities, especially in low-income countries. After KT, children with comorbidities have a similar mortality and graft survival compared with children without comorbidities. We concluded that reduced access to a kidney transplant might represent a modifiable barrier to KT in children with comorbidities, especially in low-resource countries. We suggest that children with comorbidities in need for kidney replacement therapy should be rapidly evaluated for eligibility for KT.
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| 14. |
- Sutter, D., et al.
(author)
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Orbitally selective breakdown of Fermi liquid quasiparticles in Ca1.8Sr0.2RuO4
- 2019
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In: Physical Review B. - : AMER PHYSICAL SOC. - 2469-9950 .- 2469-9969. ; 99:12
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Journal article (peer-reviewed)abstract
- We present a comprehensive angle-resolved photoemission spectroscopy study of Ca1.8Sr0.2RuO4. Four distinct bands are revealed and along the Ru-O bond direction their orbital characters are identified through a light polarization analysis and comparison to dynamical mean-field theory calculations. Bands assigned to d(xz),d(yz) orbitals display Fermi liquid behavior with fourfold quasiparticle mass renormalization. Extremely heavy fermions-associated with a predominantly d(xy) band character-are shown to display non-Fermi-liquid behavior. We thus demonstrate that Ca1.8Sr0.2RuO4 is a hybrid metal with an orbitally selective Fermi liquid quasiparticle breakdown.
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| 15. |
- Baljozovic, Milos, et al.
(author)
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Self-Assembly and Magnetic Order of Bi-Molecular 2D Spin Lattices of M(II,III) Phthalocyanines on Au(111)
- 2021
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In: MAGNETOCHEMISTRY. - : MDPI. - 2312-7481. ; 7:8
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Journal article (peer-reviewed)abstract
- Single layer low-dimensional materials are presently of emerging interest, including in the context of magnetism. In the present report, on-surface supramolecular architecturing was further developed and employed to create surface supported two-dimensional binary spin arrays on atomically clean non-magnetic Au(111). By chemical programming of the modules, different checkerboards were produced combining phthalocyanines containing metals of different oxidation and spin states, diamagnetic zinc, and a metal-free 'spacer'. In an in-depth, spectro-microscopy and theoretical account, we correlate the structure and the magnetic properties of these tunable systems and discuss the emergence of 2D Kondo magnetism from the spin-bearing components and via the physico-chemical bonding to the underlying substrate. The contributions of the individual elements, as well as the role of the electronic surface state in the bottom substrate, are discussed, also looking towards further in-depth investigations.
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| 16. |
- Generalov, Alexander, et al.
(author)
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Spin Orientation of Two-Dimensional Electrons Driven by Temperature-Tunable Competition of Spin-Orbit and Exchange-Magnetic Interactions
- 2017
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In: Nano Letters. - : American Chemical Society (ACS). - 1530-6984 .- 1530-6992. ; 17:2, s. 811-820
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Journal article (peer-reviewed)abstract
- Finding ways to create and control the spin-dependent properties of two-dimensional electron states (2DESs) is a major challenge for the elaboration of novel spin-based devices. Spin-orbit and exchange-magnetic interactions (SOI and EMI) are two fundamental mechanisms that enable access to the tunability of spin-dependent properties of carriers. The silicon surface of HoRh2Si2 appears to be a unique model system, where concurrent SOI and EMI can be visualized and controlled by varying the temperature. The beauty and simplicity of this system lie in the 4f moments, which act as a multiple tuning instrument on the 2DESs, as the 4f projections parallel and perpendicular to the surface order at essentially different temperatures. Here we show that the SOI locks the spins of the 2DESs exclusively in the surface plane when the 4f moments are disordered: the Rashba-Bychkov effect. When the temperature is gradually lowered and the system experiences magnetic order, the rising EMI progressively competes with the SOI leading to a fundamental change in the spin-dependent properties of the 2DESs. The spins rotate and reorient toward the out-of-plane Ho 4f moments. Our findings show that the direction of the spins and the spin-splitting of the two-dimensional electrons at the surface can be manipulated in a controlled way by using only one parameter: the temperature.
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| 17. |
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| 18. |
- Plumb, Jennifer C., et al.
(author)
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In Search of Meaning : Values in Modern Clinical Behavior Analysis
- 2009
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In: The Behavior analyst. - 0738-6729. ; 32:1, s. 85-103
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Journal article (peer-reviewed)abstract
- Skinner described behavior analysis as the field of values and purpose. However, he defined these concepts in terms of a history of reinforcement and failed to specify whether and how human and nonhuman values might differ. Human values have been seen as theoretically central within a number of nonbehavioral traditions in psychology, including humanism and positive psychology. However, these approaches have failed to provide explanations of the behavior-environment relations involved in valuing that might allow prediction and influence with respect to this phenomenon. Modern clinical behavior analysis in the form of acceptance and commitment therapy (ACT), however, succeeds in providing a functional definition of human values that meets this latter criterion. ACT is rooted in behavior analysis and relational frame theory (RFT) and defines values in terms of verbally established motivation. ACT empirical research into values has begun to blossom in recent years, and ACT-RFT researchers are currently investigating the concept at the most basic empirical level as well as in the applied clinical arena, heralding new interest in and insight into values within clinical behavioral psychology.
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| 19. |
- Spada, Cristiano, et al.
(author)
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Clinical indications for computed tomographic colonography: European Society of Gastrointestinal Endoscopy (ESGE) and European Society of Gastrointestinal and Abdominal Radiology (ESGAR) Guideline.
- 2014
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In: Endoscopy. - : Georg Thieme Verlag KG. - 1438-8812 .- 0013-726X. ; 46:10, s. 897-915
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Journal article (peer-reviewed)abstract
- This is an official guideline of the European Society of Gastrointestinal Endoscopy (ESGE) and the European Society of Gastrointestinal and Abdominal Radiology (ESGAR). It addresses the clinical indications for the use of computed tomographic colonography (CTC). A targeted literature search was performed to evaluate the evidence supporting the use of CTC. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was adopted to define the strength of recommendations and the quality of evidence. Main recommendations 1 ESGE/ESGAR recommend computed tomographic colonography (CTC) as the radiological examination of choice for the diagnosis of colorectal neoplasia. ESGE/ESGAR do not recommend barium enema in this setting (strong recommendation, high quality evidence). 2 ESGE/ESGAR recommend CTC, preferably the same or next day, if colonoscopy is incomplete. Delay of CTC should be considered following endoscopic resection. In the case of obstructing colorectal cancer, preoperative contrast-enhanced CTC may also allow location or staging of malignant lesions (strong recommendation, moderate quality evidence). 3 When endoscopy is contraindicated or not possible, ESGE/ESGAR recommend CTC as an acceptable and equally sensitive alternative for patients with symptoms suggestive of colorectal cancer (strong recommendation, high quality evidence). 4 ESGE/ESGAR recommend referral for endoscopic polypectomy in patients with at least one polyp ≥ 6 mm in diameter detected at CTC. CTC surveillance may be clinically considered if patients do not undergo polypectomy (strong recommendation, moderate quality evidence). 5 ESGE/ESGAR do not recommend CTC as a primary test for population screening or in individuals with a positive first-degree family history of colorectal cancer (CRC). However, it may be proposed as a CRC screening test on an individual basis providing the screenee is adequately informed about test characteristics, benefits, and risks (weak recommendation, moderate quality evidence).
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| 20. |
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| 21. |
- Tamai, Anna, et al.
(author)
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High-Resolution Photoemission on Sr2RuO4 Reveals Correlation-Enhanced Effective Spin-Orbit Coupling and Dominantly Local Self-Energies
- 2019
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In: Physical Review X. - New York : American Physical Society. - 2160-3308. ; 9:2
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Journal article (peer-reviewed)abstract
- We explore the interplay of electron-electron correlations and spin-orbit coupling in the model Fermi liquid Sr2RuO4 using laser-based angle-resolved photoemission spectroscopy. Our precise measurement of the Fermi surface confirms the importance of spin-orbit coupling in this material and reveals that its effective value is enhanced by a factor of about 2, due to electronic correlations. The self-energies for the β and γ sheets are found to display significant angular dependence. By taking into account the multi-orbital composition of quasiparticle states, we determine self-energies associated with each orbital component directly from the experimental data. This analysis demonstrates that the perceived angular dependence does not imply momentum-dependent many-body effects but arises from a substantial orbital mixing induced by spin-orbit coupling. A comparison to single-site dynamical mean-field theory further supports the notion of dominantly local orbital self-energies and provides strong evidence for an electronic origin of the observed nonlinear frequency dependence of the self-energies, leading to “kinks” in the quasiparticle dispersion of Sr2RuO4.
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