| 11. |
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| 12. |
- Buyanova, Irina, 1960-, et al.
(författare)
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On the origin of spin loss in GaMnN/InGaN Light-Emitting Diodes
- 2004
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 84, s. 2599-
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Tidskriftsartikel (refereegranskat)abstract
- Spin polarization of GaMnN/InGaN light-emitting diodes grown by molecular beam epitaxy is analyzed. In spite of the ferromagnetic behavior of the GaMnN spin injector, the diodes are shown to exhibit very low efficiency of spin injection. Based on resonant optical orientation spectroscopy, the spin loss in the structures is shown to be largely due to fast spin relaxation within the InGaN spin detector, which itself destroys any spin polarization generated by optical spin orientation or electrical spin injection.
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| 13. |
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| 14. |
- Chen, Weimin, 1959-, et al.
(författare)
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Efficient spin depolarization in ZnCdSe spin detector : an important factor limiting optical spin injection efficiency in ZnMnSe/CdZnSe spin light-emitting structures
- 2004
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 85, s. 5260-
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Tidskriftsartikel (refereegranskat)abstract
- Spin depolarization of a ZnCdSe quantum-well spin detector (SD) in ZnMnSe/ZnCdSe light-emitting quantum structures is investigated by cw and time-resolved optical orientation spectroscopy. It is shown that spin depolarization is governed by three distinct spin relaxation processes with the corresponding polarization decay times of 850, 30, and <10 ps. The dominant and the fastest process is attributed to spin relaxation accompanying energy relaxation of hot excitons (and hot carriers) within the SD, providing evidence that it can be an important source of spin loss, leading to the observed limited efficiency of optical spin injection in the structures.
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| 15. |
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| 16. |
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| 17. |
- Karle, A., et al.
(författare)
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Observation of high energy atmospheric neutrinos with AMANDA
- 2000
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Ingår i: AIP Conference Proceedings. - : American Institute of Physics (AIP). ; , s. 823-827
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Konferensbidrag (refereegranskat)abstract
- In 1997 the Antarctic Muon and Neutrino Detector Array (AMANDA) started operating with 10 strings. In an analysis of data taken during the first year of operation 188 atmospheric neutrino candidates were found. Their zenith angle distribution agrees with expectations based on Monte Carlo simulations. A preliminary upper limit is given on a diffuse flux of high energy neutrinos of astrophysical origin.
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| 18. |
- Lindholm, D, et al.
(författare)
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Neuronal apoptosis inhibitory protein : structural requirements for hippocalcin binding and effects on survival of NGF-denendent sympathetic neurons
- 2002
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Ingår i: Biochimica et Biophysica Acta - Proteins and Proteomics. - : ELSEVIER SCIENCE BV. - 1570-9639 .- 1878-1454. ; 1600:1-2, s. 138-147
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Tidskriftsartikel (refereegranskat)abstract
- Neuronal apoptosis inhibitory protein (NAIP) has been linked to the inherited disease, spinal muscular atrophy (SMA), which occurs in children with degeneration of the motorneurons. In the nervous system, NAIP is expressed by specific classes of neurons including spinal -motorneurons. Recently, NAIP was shown to interact with hippocalcin, which belongs to the neuronal calcium sensor (NCS) protein family. Here we-have studied this interaction in more detail, using deletions and a mutagenesis of the third baculovirus inhibitory repeat (BIR) motif in NAIP, and functional assays for neuronal death. The results showed that specific amino acids and the zinc finger domain in BIR3 are needed for efficient interaction of NAIP with hippocalcin. Cotransfections of NAIP-BIR3 and hippocalcin resulted in translocation and colocalisation of the two proteins in neuroblastoma cells. This was accompanied by an enhanced resistance towards cell death induced by high levels of calcium. In contrast, expression of NAIP-BIR3 and hippocalcin in sympathetic neurons did not protect against death induced by nerve growth factor (NGF) withdrawal. The results demonstrate a functional interaction of hippocalcin with NAIP-BIR3, which in neuroblastoma cells leads to rescue of cells after high intracellular calcium, but which in sympathetic neurons had no significant effect. The results indicate that NAIP in conjunction with hippocalcin can affect the survival of some, but not all neural cells, and this interaction may play a role in the neurodegenerative processes in SMA, and possible other human disorders. (C) 2002 Elsevier Science B.V All rights reserved.
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| 19. |
- Niessen, Peter, et al.
(författare)
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Recent results from the amanda experiment
- 2003
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Ingår i: Proceedings of 38th Rencontres de Moriond on Electroweak Interactions and Unified Theories 15-22 Mar 2003. Les Arcs, France.
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Konferensbidrag (refereegranskat)abstract
- AMANDA (Antarctic Muon And Neutrino Detector Array) is a neutrino telescope built under the southern polar icecap and its scope is to explore the possibility to detect high energy cosmic neutrinos. This should generate insight into the powerful celestial objects where acceleration mechanisms can bring up to 10 20 eV. We describe the achievements and results from the AMANDA-B10 prototype and the preliminary results from the current AMANDA-II detector which show dramatic increase in sensitivity.
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| 20. |
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