| 1. |
- Gadea, A., et al.
(författare)
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Observation of Ni-54 : Cross-conjugate symmetry in f(7/2) mirror energy differences
- 2006
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 97:15, s. 152501-
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Tidskriftsartikel (refereegranskat)abstract
- Gamma decays from excited states up to J(pi)=6(+) in the N=Z-2 nucleus Ni-54 have been identified for the first time. Level energies are compared with those of the isobars Co-54 and Fe-54 and of the cross-conjugate nuclei of mass A=42. The good but puzzling f(7/2) cross-conjugate symmetry in mirror and triplet energy differences is analyzed. Shell model calculations reproduce the new data but the necessary nuclear charge-dependent phenomenology is not fully explained by modern nucleon-nucleon potentials.
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| 2. |
- Sohler, D, et al.
(författare)
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Maximally Aligned States in the Proton Drip Line Nucleus 106Sb
- 2005
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Ingår i: Nuclear Physics, Section A. - : Elsevier BV. - 0375-9474 .- 1873-1554. ; 753:3-4, s. 251-262
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Tidskriftsartikel (refereegranskat)abstract
- High-spin states in Sb-106 have been investigated in the Fe-54(Ni-58, 1α 1p1n) reaction by in-beam γ-spectroscopic methods using the EUROBALL detector array equipped with charged particle and neutron detectors. On the basis of measured γγ-coincidence relations, angular distributions, and linear polarization ratios a significantly extended level scheme has been constructed up to spin and parity I-π = (19(-)) and E-x ∼ 6.5 MeV. The experimental results are interpreted within the framework of the gdsh shell model using a realistic effective nucleon-nucleon interaction. Candidates for states with fully aligned angular momenta in the π(d(5/2), g(7/2))(1) v (d(5/2), g(7/2))(5) valence space are identified at 4338 and 5203 keV, as well as in the π(d(5/2), g(7/2))(1) V(d(5/2), g(7/2))(4)h(11/2)(1) space at 6087, 6573 and 6783 keV.
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| 3. |
- Wadsworth, R., et al.
(författare)
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THE NORTHWEST FRONTIER : SPECTROSCOPY OF N similar to Z NUCLEI BELOW MASS 100
- 2009
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Ingår i: Acta Physica Polonica B. - 0587-4254 .- 1509-5770. ; 40:3, s. 611-620
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Tidskriftsartikel (refereegranskat)abstract
- The spectroscopy and structure of excited states of N similar to Z nuclei in the mass 70-100 region has been investigated using two techniques. In the A similar to 70-80 region fusion evaporation reactions coupled with the recoil-beta-tagging method have been employed at Jyvaskyla to study low-lying states in odd-odd N = Z nuclei. Results from these and other data for known odd-odd nuclei above mass 60 will be discussed. In the heavier mass 90 region a fragmentation experiment has been performed using the RIS-ING/FRS setup at GSI. This experiment was primarily aimed at searching for spin gap isomers in nuclei around A similar to 96. The objectives of the latter experiment will be discussed.
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| 4. |
- Wollersheim, HJ, et al.
(författare)
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Rare ISotopes INvestigation at GSI (RISING) Using Gamma-ray Spectroscopy at Relativistic Energies
- 2005
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; 537:3, s. 637-657
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Tidskriftsartikel (refereegranskat)abstract
- The Rare ISotopes INvestigation at GSI project combines the former EUROBALL Ge-Cluster detectors, the MINIBALL Ge detectors, BaF2--HECTOR detectors, and the fragment separator at GSI for high-resolution in-beam gamma-ray spectroscopy measurements with radioactive beams. These secondary beams produced at relativistic energies are used for Coulomb excitation or secondary fragmentation experiments in order to explore the nuclear structure of the projectiles or projectile like nuclei by measuring de-excitation photons. The newly designed detector array is described and the performance characteristics are given. Moreover, particularities of the experimental technique are discussed.
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| 5. |
- Palacz, M, et al.
(författare)
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Highly efficient charged particle veto detector CUP
- 2005
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 550:1-2, s. 414-424
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Tidskriftsartikel (refereegranskat)abstract
- A novel, highly efficient, plastic scintillator detector has been constructed. The primary application of the detector is to act as a veto device in heavy-ion-induced fusion-evaporation reactions, in which the structure of proton-rich nuclides is investigated by gamma-ray spectroscopy methods. The detector rejects events in which light charged particles, like protons and alpha particles, are emitted in the evaporation process, facilitating selection of reaction channels associated with emission of only neutrons. The detector was used in a EUROBALL experiment, with achieved efficiencies of 80% and 63% for protons and alpha particles, respectively. The design of the detector, its performance and limitations are discussed.
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| 6. |
- Banu, A, et al.
(författare)
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108Sn Studied with Intermediate-energy Coulomb Excitation
- 2005
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 72:6
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Tidskriftsartikel (refereegranskat)abstract
- The unstable neutron-deficient Sn-108 isotope has been studied in inverse kinematics by intermediate-energy Coulomb excitation using the RISING/FRS experimental setup at GSI. This is the highest Z nucleus studied so far with this method. Its reduced transition probability B (E2;0(g.s.)(+)-> 2(1)(+)) has been measured for the first time. The extracted B(E2) value of 0.230(57)e(2) b(2) has been determined relative to the known value in the stable Sn-112 isotope. The result is discussed in the framework of recent large-scale shell model calculations performed with realistic effective interactions. The roles of particle-hole excitations of the Sn-100 core and of the Z=50 shell gap for the E2 polarization are investigated.
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| 7. |
- Mach, Henryk, et al.
(författare)
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The single-particle and collective features in the nuclei just above Sn-132
- 2007
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Ingår i: Acta Physica Polonica B. - 0587-4254 .- 1509-5770. ; 38:4, s. 1213-1218
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Tidskriftsartikel (refereegranskat)abstract
- The Advanced Time Delayed method has been used to measure the lifetimes of excited states in the exotic nuclei Sb-134, Sb-135 and Te-136 populated in the beta decay of Sn-134, Sn-135 and Sn-136, respectively. High purity Sn beams were extracted at the ISOLDE separator using a novel production technique utilizing the molecular SnS+ beams to isolate Sn from contaminating other fission products. Among the new results we have identified the 1/2(+) state in Sb-135 and its E2 transition to the lower-lying 5/2(+) state was found to be surprisingly collective. This measurement represents also one of the first applications of the LaBr3 scintillator to ultra fast timing.
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| 8. |
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| 9. |
- Assié, M., et al.
(författare)
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Neutron correlations in 6He viewed through nuclear break-up
- 2009
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Ingår i: European Physical Journal A. - : Springer Science and Business Media LLC. - 1434-6001 .- 1434-601X. ; 42:3, s. 441-446
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Tidskriftsartikel (refereegranskat)abstract
- The nuclear break-up of He-6 on a Pb-208 target was studied at 20 A MeV using a secondary beam of He-6 produced by the SPIRAL facility at GANIL. alpha-particles were detected in coincidence with two neutrons with a large angular coverage and the reaction mechanism was identified. From the distribution of the relative angles between the two neutrons the correlation function was extracted. It shows a strong correlation at small relative angles attributed to the contribution of the di-neutron configuration of He-6.
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| 14. |
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| 15. |
- Nilsson, A., et al.
(författare)
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The hydrogen bond in ice probed by soft x-ray spectroscopy and density functional theory
- 2005
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Ingår i: Journal of Chemical Physics. - : American Institute of Physics. - 1089-7690 .- 0021-9606. ; 122, s. 154505-
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Tidskriftsartikel (refereegranskat)abstract
- We combine photoelectron and x-ray absorption spectroscopy with density functional theory to derive a molecular orbital picture of the hydrogen bond in ice. We find that the hydrogen bond involves donation and back-donation of charge between the oxygen lone pair and the O–H antibonding orbitals on neighboring molecules. Together with internal s-p rehybridization this minimizes the repulsive charge overlap of the connecting oxygen and hydrogen atoms, which is essential for a strong attractive electrostatic interaction. Our joint experimental and theoretical results demonstrate that an electrostatic model based on only charge induction from the surrounding medium fails to properly describe the internal charge redistributions upon hydrogen bonding.
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| 16. |
- Vilen, ST, et al.
(författare)
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Intracellular co-localization of trypsin-2 and matrix metalloprotease-9: Possible proteolytic cascade of trypsin-2, MMP-9 and enterokinase in carcinoma
- 2008
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Ingår i: Experimental Cell Research. - : Elsevier BV. - 1090-2422 .- 0014-4827. ; 314:4, s. 914-926
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Tidskriftsartikel (refereegranskat)abstract
- Tumor-associated trypsin-2 and matrix metalloprotease-9 (MMP-9) are associated with cancer, particularly with invasive squamous cell carcinomas. They require activation for catalytical competence via proteolytic cascades. One cascade is formed by enterokinase, trypsin-2 and MMP-9; enterokinase activates trypsinogen-2 to trypsin-2, which is an efficient proMMP-9 activator. We describe here that oral squamous cell carcinomas express all members of this cascade: MMP-9, trypsin-2 and enterokinase. The expression of enterokinase in a carcinoma cell line not derived from the duodenum was shown here for the first time. Enterokinase directly cleaved proMMP-9 at the Lys(65)-Ser(66) site, but failed to activate it in vitro. We demonstrated by confocal microscopy that MMP-9 and trypsin-2 co-localized in intracellular vesicles of the carcinoma cells. This co-localization of trypsin-2 and MMP-9 resulted in intracellular proMMP-9 processing that represented fully or partially activated MMP-9. However, although both proteases were present also in various bone tumor tissues, MMP-9 and trypsin-2 never co-localized at the cellular level in these tissues. This suggests that the intracellular vesicular co-localization, storage and possible activation of these proteases may be a unique feature for aggressive epithelial tumors, such as squamous cell carcinomas, but not for tumors of mesenchymal origin.
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| 17. |
- Ali, M Al Haj, et al.
(författare)
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Distribution of neuroendocrine cells in the small and large intestines of the one-humped camel (Camelus dromedarius)
- 2007
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Ingår i: Neuropeptides. - : Elsevier BV. - 0143-4179 .- 1532-2785. ; 41:5, s. 293-299
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Tidskriftsartikel (refereegranskat)abstract
- The distribution and relative frequency of neuroendocrine cells in the small and large intestines of one-humped camel were studied using antisera against 5-hydroxytryptamine (5-HT), cholecystokinin (CCK-8), somatostatin (SOM), peptide tyrosine tyrosine (PYY), gastric inhibitory polypeptide (GIP), neuronal nitric oxide synthase (nNOS), gastrin releasing peptide (GRP), substance P (SP), and neurokinin A (NKA). Among these cell types, CCK-8 immunoreactive (IR) cells were uniformly distributed in the mucosa, while others showed varied distribution in the villi or crypts of the small intestine. Immunoreactive cells like 5HT, CCK-8, and SOM showed peak density in the villi and crypts of the small intestine and in the colonic glands of the large intestine, while cells containing SP were discerned predominately in the crypts. 5-HT, CCK-8 and SOM cells were mainly flask-shaped and of the open-variety, while PYY and SP immunoreactive cells were mainly rounded or basket-shaped and of the closed variety. Basically the distribution pattern of the endocrine cells in the duodenum, jejunum and colon of the one-humped camel is similar to that of other mammals. Finally, the distribution of these bioactive agents may give clues as to how these agents aid in the function of the intestinal tract of this desert animal.
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| 18. |
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| 19. |
- Atac Nyberg, Ayse, et al.
(författare)
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Discrimination of gamma rays due to inelastic neutron scattering in AGATA
- 2009
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 607:3, s. 554-563
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Tidskriftsartikel (refereegranskat)abstract
- Possibilities of discriminating neutrons and gamma rays in the AGATA gamma-ray tracking spectrometer have been investigated with the aim of reducing the background due to inelastic scattering of neutrons in the high-purity germanium crystals. This background may become a serious problem especially in experiments with neutron-rich radioactive ion beams. Simulations using the GEANT4 toolkit and a tracking program based on the forward tracking algorithm were carried out by emitting neutrons and gamma rays from the center of AGATA. Three different methods were developed and tested in order to find "fingerprints" of the neutron interaction points in the detectors. In a simulation with simultaneous emission of six neutrons with energies in the range 1-5 MeV and 10 gamma rays with energies between 150 and 1450 keV, the peak-to-background ratio at a gamma-ray energy of 1.0 MeV was improved by a factor of 2.4 after neutron rejection with a reduction of the photopeak efficiency at 1.0 MeV of only a factor of 1.25. (C) 2009 Elsevier B.V. All rights reserved.
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| 20. |
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| 21. |
- Barkauskaite, V, et al.
(författare)
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Translocation of the novel cytokine HMGB1 to the cytoplasm and extracellular space coincides with the peak of clinical activity in experimentally UV-induced lesions of cutaneous lupus erythematosus
- 2007
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Ingår i: Lupus. - : SAGE Publications. - 0961-2033 .- 1477-0962. ; 16:10, s. 794-802
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Tidskriftsartikel (refereegranskat)abstract
- HMGB1 is a pro-inflammatory cytokine that together with TNF-α and IL-1β is involved in the pathogenesis of spontaneously occurring skin lesions in lupus erythematosus. The purpose of the present study was to explore the sequence of events in HMGB1, TNF-α and IL-1β expression under development and resolution of experimentally induced CLE lesions. The study involved investigation of 38 serial skin biopsies acquired from photoprovoked skin lesions of nine CLE patients, using immunohistochemical staining of tissue sections. In biopsies from the clinically most active phase of skin involvement extracellular, secreted HMGB1 and increased cytoplasmic HMGB1 were found, as compared with the late and fading lesions or non-lesional skin. Besides HMGB1, increased expression of TNF-α and IL-1β was observed in dermal infiltrates of the induced CLE lesions. These cytokines were however not upregulated in all lesions, and increased expression of IL-1β was seen predominantly in late biopsies. In conclusion, extracellular and cytoplasmic HMGB1 coincides with the clinically most active phase of photoinduced lesions of cutaneous lupus, and suggests that HMGB1 is an important factor in the inflammatory autoimmune process of CLE. HMGB1 can induce expression of TNF-α and IL-1β, and formation of a pro-inflammatory loop between HMGB1, TNF-α, and IL-1β may be responsible for the prolonged and sustained inflammation in CLE. Lupus (2007) 16, 794—802.
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