| 1. |
- Fredholm, BB, et al.
(författare)
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Consequences of eliminating adenosine A(1) receptors in mice
- 2003
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Ingår i: Drug Development Research (Proceedings of the Seventh International Symposium on Adenosine and Adenine Nucleotides - Part 1). - : Wiley. - 1098-2299 .- 0272-4391. ; 58, s. 350-
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Konferensbidrag (refereegranskat)abstract
- The second coding exon of the adenosine A, receptor gene was eliminated by homologous recombination. The phenotype of mice (mixed C57B6/129OlaHsd background) was studied, using siblings from matings of heterozygous mice. Among the offspring the ratio between+/+, +/-and -/-animals was 1:2:1. Over the first half-year-at least-growth and viability were the same in all genotypes. Binding of A(1) ligands was eliminated in-/-mice and halved in+/-mice. Blood pressure was increased in-/-mice and this was paralleled by an increase in plasma renin. Heart rate was unaffected, as was contractility. Furthermore, the response of the perfused heart to ischemia was similar in+/+and -/-hearts. However, remote preconditioning was eliminated in-/-mouse hearts. Tubuloglomerular feedback in the kidney was also lost in-/-mice. The analgesic response to a non-selective adenosing receptor agonist was lost in-/-mice, which also showed hyperalgesia in the tail-flick test. There was a slight hypoactivity in-/-mice, but responses to caffeine were essentially normal. The inhibition of excitatory neurotransmission in hippocampus by adenosine was lost in-/-mice and reduced in+/-mice. Responses to ATP were affected similarly. Hypoxic depression of synaptic transmission was essentially eliminated in hippocampus and hypoxic decrease in spinal respiratory neuron firing was markedly reduced. These results show that adenosine A, receptors play a physiologically important role in the kidney, spinal cord, and hippocampus and that they are critically important in the adaptive responses to hypoxia. (C) 2003 Wiley-Liss, Inc.
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| 2. |
- Fedorov, A. V., et al.
(författare)
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Insight into the Temperature Evolution of Electronic Structure and Mechanism of Exchange Interaction in EuS
- 2021
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Ingår i: Journal of Physical Chemistry Letters. - : American Chemical Society (ACS). - 1948-7185. ; 12:34, s. 8328-8334
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Tidskriftsartikel (refereegranskat)abstract
- Discovered in 1962, the divalent ferromagnetic semiconductor EuS (TC = 16.5 K, Eg = 1.65 eV) has remained constantly relevant to the engineering of novel magnetically active interfaces, heterostructures, and multilayer sequences and to combination with topological materials. Because detailed information on the electronic structure of EuS and, in particular, its evolution across TC is not well-represented in the literature but is essential for the development of new functional systems, the present work aims at filling this gap. Our angle-resolved photoemission measurements complemented with first-principles calculations demonstrate how the electronic structure of EuS evolves across a paramagnetic-ferromagnetic transition. Our results emphasize the importance of the strong Eu 4f-S 3p mixing for exchange-magnetic splittings of the sulfur-derived bands as well as coupling between f and d orbitals of neighboring Eu atoms to derive the value of TC accurately. The 4f-3p mixing facilitates the coupling between 4f and 5d orbitals of neighboring Eu atoms, which mainly governs the exchange interaction in EuS.
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| 3. |
- Schulz, S., et al.
(författare)
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Classical and cubic Rashba effect in the presence of in-plane 4f magnetism at the iridium silicide surface of the antiferromagnet GdIr2Si2
- 2021
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Ingår i: Physical Review B. - 2469-9950. ; 103:3
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Tidskriftsartikel (refereegranskat)abstract
- We present a combined experimental and theoretical study of the two-dimensional electron states at the iridium-silicide surface of the antiferromagnet GdIr2Si2 above and below the Néel temperature. Using angle-resolved photoemission spectroscopy (ARPES) we find a significant spin-orbit splitting of the surface states in the paramagnetic phase. By means of ab initio density-functional-theory (DFT) calculations we establish that the surface electron states that reside in the projected band gap around the M¯ point exhibit very different spin structures which are governed by the conventional and the cubic Rashba effect. The latter is reflected in a triple spin winding, i.e., the surface electron spin reveals three complete rotations upon moving once around the constant energy contours. Below the Néel temperature, our ARPES measurements show an intricate photoemission intensity picture characteristic of a complex magnetic domain structure. The orientation of the domains, however, can be clarified from a comparative analysis of the ARPES data and their DFT modeling. To characterize a single magnetic domain picture, we resort to the calculations and scrutinize the interplay of the Rashba spin-orbit coupling field with the in-plane exchange field, provided by the ferromagnetically ordered 4f moments of the near-surface Gd layer.
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| 4. |
- Usachov, D. Yu, et al.
(författare)
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Cubic Rashba Effect in the Surface Spin Structure of Rare-Earth Ternary Materials
- 2020
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Ingår i: Physical Review Letters. - 0031-9007. ; 124:23
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Tidskriftsartikel (refereegranskat)abstract
- Spin-orbit interaction and structure inversion asymmetry in combination with magnetic ordering is a promising route to novel materials with highly mobile spin-polarized carriers at the surface. Spin-resolved measurements of the photoemission current from the Si-terminated surface of the antiferromagnet TbRh2Si2 and their analysis within an ab initio one-step theory unveil an unusual triple winding of the electron spin along the fourfold-symmetric constant energy contours of the surface states. A two-band k·p model is presented that yields the triple winding as a cubic Rashba effect. The curious in-plane spin-momentum locking is remarkably robust and remains intact across a paramagnetic-antiferromagnetic transition in spite of spin-orbit interaction on Rh atoms being considerably weaker than the out-of-plane exchange field due to the Tb 4f moments.
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