| 1. |
- Fedorov, R V, et al.
(författare)
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Structure of ribosomal protein TL5 complexed with RNA provides new insights into the CTC family of stress proteins
- 2001
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Ingår i: Acta Crystallographica. Section D: Biological Crystallography. - 1399-0047. ; D57:7, s. 968-976
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Tidskriftsartikel (refereegranskat)abstract
- The crystal structure of Thermus thermophilus ribosomal protein TL5 in complex with a fragment of Escherichia coli 5S rRNA has been determined at 2.3 Å resolution. The protein consists of two domains. The structure of the N-terminal domain is close to the structure of E. coli ribosomal protein L25, but the C-terminal domain represents a new fold composed of seven -strands connected by long loops. TL5 binds to the RNA through its N-terminal domain, whereas the C-terminal domain is not included in this interaction. Cd2+ ions, the presence of which improved the crystal quality significantly, bind only to the protein component of the complex and stabilize the protein molecule itself and the interactions between the two molecules in the asymmetric unit of the crystal. The TL5 sequence reveals homology to the so-called general stress protein CTC. The hydrophobic cores which stabilize both TL5 domains are highly conserved in CTC proteins. Thus, all CTC proteins may fold with a topology close to that of TL5.
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| 2. |
- Korkishko, Y. N., et al.
(författare)
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Proton exchanged LiNbO3 optical waveguides : Nonlinear, electrooptical and photorefractive properties
- 2001
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Ingår i: Ferroelectrics (Print). - 0015-0193 .- 1563-5112. ; 264:04-jan, s. 1983-1988
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Tidskriftsartikel (refereegranskat)abstract
- We show that proton exchanged LiNbO3 waveguides exhibit very complex structural chemistry. Seven HxLi1-xNbO3 crystallographic phases have been identified in PE LiNbO3 waveguides. A correlation is done between the electroptical, nonlinear and photorefractive properties, the processing conditions and the refractive index changes of the waveguides.
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| 3. |
- Shergur, J., et al.
(författare)
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beta-decay studies of Sn135-137 using selective resonance laser ionization techniques
- 2002
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Ingår i: Physical Review C - Nuclear Physics. - 2469-9985 .- 2469-9993. ; 65:3
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Tidskriftsartikel (refereegranskat)abstract
- The decays of the very neutron rich Sn isotopes Sn135-137 were studied at CERN/ISOLDE using isotopic and isobaric selectivity achieved by the use of a resonance ionization laser ion source and mass spectroscopy, respectively. Neutron decay rates, gamma-ray singles, and gamma-gamma coincidence data were collected as a function of time. The half-life (T-1/2) and delayed neutron emission probability (P-n) values of 135 Sn were measured to be 530(20) ms and 21(3)%, respectively. For Sn-136, a T-1/2 of 250(30) ms was determined along with a P-n value of 30(5)%. For Sn-137, a T-1/2 of 190(60) ms and a P-n value of 58(15)% were deduced. Identification of low-energy transitions in Sb-135 was made possible by comparison of laser-on and laser-off gamma-ray spectra. Those data combined with gamma-gamma coincidence spectra were used to construct a level scheme for Sb-135 that includes an unexpectedly low first excited state at 282 keV. A ground state beta branch of 33.2% was measured by following the growth and decay of the Sb-135 daughter. Shell-model calculations are consistent with the observed Sb-135 level structure and can account for a lowered first excited state.
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| 4. |
- Korkishko, Y. N., et al.
(författare)
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Proton exchanged LiNbO3 and LiTaO3 optical waveguides and integrated optic devices
- 2003
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Ingår i: Microelectronic Engineering. - 0167-9317 .- 1873-5568. ; 69:04-feb, s. 228-236
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Tidskriftsartikel (refereegranskat)abstract
- We show that proton exchanged LiNbO3 waveguides exhibit very complex structural chemistry. Seven HxLi1-xNbO3 and six HxLi1-xTaO3 crystallographic phases have been identified in PE LiNbO3 and LiTaO3 waveguides, respectively. A correlation is done between the electrooptical, nonlinear and photorefractive properties, the processing conditions and the refractive index changes of the waveguides. Some integrated optical devices have been realized.
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| 5. |
- Krebs, C. J., et al.
(författare)
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Terrestrial trophic dynamics in the Canadian Arctic
- 2003
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Ingår i: Canadian Journal of Zoology-Revue Canadienne De Zoologie. ; 81, s. 827-843
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Tidskriftsartikel (refereegranskat)abstract
- The Swedish Tundra Northwest Expedition of 1999 visited 17 sites throughout the Canadian Arctic. At 12 sites that were intensively sampled we estimated the standing crop of plants and the densities of herbivores and predators with an array of trapping, visual surveys, and faecal-pellet transects. We developed a trophic-balance model using ECOPATH to integrate these observations and determine the fate of primary and secondary production in these tundra ecosystems, which spanned an 8-fold range of standing crop of plants. We estimated that about 13% of net primary production was consumed by herbivores, while over 70% of small-herbivore production was estimated to flow to predators. Only 9% of large-herbivore production was consumed by predators. Organization of Canadian Arctic ecosystems appears to be more top-down than bottom-up. Net primary production does not seem to be herbivore-limited at any site. This is the first attempt to integrate trophic dynamics over the entire Canadian Arctic.
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| 6. |
- Shergur J, Brown BA, Fedoseyev V, Koster U, Kratz KL, Sweryniak D, Walters WB, Wohr A, Fedorov D, Hannawald M, Hjorth-Jensen M, Mishin V, Pfeiffer B, Ressler JJ, Fynbo HOU, Hoff P, Mach H, Nilsson T, Wilhelmsen-Rolander K, Simon H, Bickley A and the ISOLD
(författare)
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Beta-Decay Studies of 135-137Sn using Selective Resonance Laser Ionization Techniques
- 2002
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Ingår i: Phys. Rev.. ; C65, s. 34313-
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Tidskriftsartikel (refereegranskat)
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| 7. |
- Shergur, J., et al.
(författare)
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Decay of Sn-135,Sn-136 isolated by use of a laser ion source and evidence for a more harmonic-oscillator-like nuclear potential
- 2001
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Ingår i: Nuclear Physics A. - 0375-9474. ; 682, s. 493C-497C
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Konferensbidrag (refereegranskat)abstract
- The use of a resonance ionization laser ion source at CERN/ISOLDE has made it possible to study the decay of very neutron-rich Sn135-137. The decay of Sn-135 is found to populate low-energy levels in Sb-135 via direct beta decay and the first excited state in Sb-134 by beta-delayed neutron emission. The level structure of Sb-135 Will be discussed and a possible signature for a more diffuse nuclear surface considered.
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| 8. |
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| 9. |
- Korkishko, Y. N., et al.
(författare)
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Second-order optical non-linearity of proton exchanged lithium tantalate waveguides
- 2001
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Ingår i: Applied physics. B, Lasers and optics (Print). - : Springer Science and Business Media LLC. - 0946-2171 .- 1432-0649. ; 73:06-maj, s. 519-522
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Tidskriftsartikel (refereegranskat)abstract
- A detailed correlation between the fabrication conditions, crystallographic phase state of HxLi1-xTaO3 waveguides and second-order optical non-linearity has been investigated by using reflected SHG measurements from the polished waveguide end face. The non-linearity, strongly reduced after the initial proton exchange, is found to be restored and even increased after annealing. However, this apparent increase in the non-linearity is accompanied by a strong degradation of the quality of the SHG reflected beam in the region of the initial as-exchanged waveguide due to beam scattering. The high temperature proton exchange technique has been shown to produce high-quality alpha -phase waveguides with essentially undegraded non-linear optical properties. There is no phase transition when the alpha -phase waveguides are fabricated by direct exchange. This phase presents the same crystalline structure as that of LiTaO3 and maintains the excellent non-linear properties of the bulk material. The results obtained are important for the design fabrication and optimization of guided-wave non-linear optical devices in LiTaO3.
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| 10. |
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