| 1. |
- Joss, D. T., et al.
(författare)
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Yrast states and band crossings in the neutron-deficient platinum isotopes Pt169-173
- 2006
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 74:1
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Tidskriftsartikel (refereegranskat)abstract
- The yrast states in the light platinum isotopes Pt169-173 have been investigated in a recoil-decay tagging experiment using the JUROGAM gamma-ray spectrometer in conjunction with the RITU gas-filled recoil separator and the GREAT tagging spectrometer. Gamma-ray transitions have been established for the first time in the odd-N isotopes, Pt-169 and Pt-173, and the yrast sequences in Pt-170 and Pt-172 have been extended. We discuss the possibility that the weakly deformed yrast structures of Pt-170, Pt-172, and Pt-173 are crossed by a deformed intruder configuration at spin similar to 8h.
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| 2. |
- Joss, D. T., et al.
(författare)
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Yrast structures in the light Pt isotopes Pt169-173
- 2005
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Ingår i: Journal of Physics G. - : IOP Publishing. - 0954-3899 .- 1361-6471. ; 31:10, s. S1715-S1718
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Tidskriftsartikel (refereegranskat)abstract
- The exploitation of the recoil-decay tagging (RDT) technique has reinvigorated experimental investigations of the shape coexistence phenomenon in heavy neutron-deficient nuclei. In a recent experiment using the JUROGAM and GREAT spectrometers in conjunction with the RITU gas-filled separator, excited states have been investigated in the light platinum isotopes. In addition to extending the yrast sequences in Pt-170 and Pt-172, the first observation of excited states in the odd-N isotopes, Pt-169 and Pt-173, is reported. The bands are discussed in terms of trends in level excitation energies as a function of neutron number.
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| 3. |
- Grahn, T., et al.
(författare)
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Collectivity and configuration mixing in Pb186,188 and Po194
- 2006
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 97:6
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Tidskriftsartikel (refereegranskat)abstract
- Lifetimes of prolate intruder states in Pb186 and oblate intruder states in Po194 have been determined by employing, for the first time, the recoil-decay tagging technique in recoil distance Doppler-shift lifetime measurements. In addition, lifetime measurements of prolate states in Pb188 up to the 8+ state were carried out using the recoil-gating method. The B(E2) values have been deduced from which deformation parameters |β2|=0.29(5) and |β2|=0.17(3) for the prolate and the oblate bands, respectively, have been extracted. The results also shed new light on the mixing between different shapes.
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| 4. |
- Lagergren, Karin, et al.
(författare)
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High-spin states in the proton-unbound nucleus Re-161
- 2006
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 74:2, s. 024316-
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Tidskriftsartikel (refereegranskat)abstract
- Excited states in Re-161 were populated using the Cd-106(Ni-58, p2n) reaction at a beam energy of 270 MeV, resulting in the first observation of gamma rays emitted from this nucleus. The reaction products were separated from scattered beam and fission fragments by the gas-filled recoil separator RITU, and were implanted in the double-sided silicon strip detectors of the GREAT spectrometer. Prompt gamma rays were detected by the JUROGAM Ge detector array and were assigned to Re-161 based on alpha- and proton-decay tagging of the implanted reaction products. The near-yrast high-spin level structure, which was delineated to spins around 39/2, is discussed in the context of the total Routhian surface formalism. The level scheme is interpreted in terms of the alignment of h(9/2)/f(7/2) neutrons at lower spins, followed by excitations involving the pi h(11/2) subshell at higher spins.
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| 5. |
- Pirinen, E., et al.
(författare)
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Enhanced polyamine catabolism alters homeostatic control of white adipose tissue mass, energy expenditure, and glucose metabolism
- 2007
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Ingår i: Mol Cell Biol. - 0270-7306. ; 27:13, s. 4953-67
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Tidskriftsartikel (refereegranskat)abstract
- Peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1 alpha) is an attractive candidate gene for type 2 diabetes, as genes of the oxidative phosphorylation (OXPHOS) pathway are coordinatively downregulated by reduced expression of PGC-1 alpha in skeletal muscle and adipose tissue of patients with type 2 diabetes. Here we demonstrate that transgenic mice with activated polyamine catabolism due to overexpression of spermidine/spermine N(1)-acetyltransferase (SSAT) had reduced white adipose tissue (WAT) mass, high basal metabolic rate, improved glucose tolerance, high insulin sensitivity, and enhanced expression of the OXPHOS genes, coordinated by increased levels of PGC-1 alpha and 5'-AMP-activated protein kinase (AMPK) in WAT. As accelerated polyamine flux caused by SSAT overexpression depleted the ATP pool in adipocytes of SSAT mice and N(1),N(11)-diethylnorspermine-treated wild-type fetal fibroblasts, we propose that low ATP levels lead to the induction of AMPK, which in turn activates PGC-1 alpha in WAT of SSAT mice. Our hypothesis is supported by the finding that the phenotype of SSAT mice was reversed when the accelerated polyamine flux was reduced by the inhibition of polyamine biosynthesis in WAT. The involvement of polyamine catabolism in the regulation of energy and glucose metabolism may offer a novel target for drug development for obesity and type 2 diabetes.
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| 6. |
- Wiseman, D. R., et al.
(författare)
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In-beam gamma-ray spectroscopy of Po-190,Po-197
- 2007
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Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 34:3, s. 275-281
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Tidskriftsartikel (refereegranskat)abstract
- gamma-ray transitions in the neutron-deficient nuclei Po-190,Po-197 have been identified using the JUROGAM Ge detector array coupled to the RITU gas-filled separator and the GREAT spectrometer. The yrast band of Po-190 has been firmly established through gamma-gamma coincidences and extended up to a spin and parity of 14(+). It displays similar behaviour to its isotones Hg-186 and Pb-188 above the 4(+) level, thus confirming its prolate nature. In Po-197 the band built upon the 13/2(+) isomer has been extended up to a spin and parity of 33/2(+), while the non-yrast band has been observed for the first time. The behaviour of Po-197 is found to be similar to that of the nearby even-mass isotopes, which is consistent with the model in which the i(13/2) neutron is weakly coupled to the states in the even-even core.
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| 7. |
- Wiseman, D. R., et al.
(författare)
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Probe of triple shape coexistence in neutron deficient polonium nuclei
- 2006
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Ingår i: AIP Conf. Proc.. - : AIP. - 0735403236 - 9780735403239 ; , s. 560-562
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Konferensbidrag (refereegranskat)abstract
- γ-ray transitions in the neutron deficient 190,197Po nuclei have been identified. The yrast band of 190Po has been extended up to a spin and parity of 14+ and is found to display similar systematic behaviour to isotones 186Hg and 188Pb above the 4+ level, thus confirming its prolate nature. In 197Po the band built upon the 13/2+ isomer has been extended up to a spin and parity of 33/2+, while the non-yrast side-band has been observed for the first time. The behaviour of 197Po is found to be similar to that of the nearby even-mass isotopes, which is consistent with the model in which the i13/2 neutron is weakly coupled to the states in the even-even core.
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| 8. |
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| 9. |
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| 10. |
- Ekman, Jörgen, et al.
(författare)
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Retention of Pb isotopes in glass surfaces for retrospective assessment of radon exposure
- 2006
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Ingår i: Nuclear Instruments and Methods in Physics Research Section B. - : Elsevier. - 0168-583X .- 1872-9584. ; 249:1-2, s. 544-547
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Tidskriftsartikel (refereegranskat)abstract
- In recent years there has been increasing interest in radio-epidemiological techniques to retrospectively measure the radon dose exposure by determining the activity of 210Pb, the longest-lived 222Rn progeny, in glass surface layers. In this study the diffusion of 39 keV 209Pb+ ions implanted into glass using the IGISOL facility has been studied under conditions that mimic the recoil implantation of 210Pb from 222Rn. The resulting depth distributions of 209Pb were then measured after heat treatment in vacuum at different temperatures by a sputter erosion technique. The diffusion coefficient could be described by an Arrhenius equation D = D0exp(−H/kT) where and H = 2.81 ± 0.11 eV. No statistically significant loss of 209Pb from the sample was observed for annealing between 470 and 600 °C.
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