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- Juhlin, Christopher, et al.
(författare)
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Crustal evolution of the Middle Urals based on seismic reflection and refraction data
- 1996
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Ingår i: Tectonophysics. - : Elsevier. - 0040-1951 .- 1879-3266. ; 264:1-4, s. 21-34
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Integration of seismic refraction and deep reflection data from the Middle Urals of central Russia provides important new constraints on the structure of the Uralian crust. Re-analysis of the GRANIT refraction profile and comparison with coincident reflection data from the ESRU profile shows a high-velocity (7.6-7.8 km/s) root zone from c. 45 to 55 km with low reflectivity beneath the Urals. We interpret this interval as crustal material, consistent with previous Russian interpretations of this velocity anomaly. Above this crustal root, one of the principle features imaged on the ESRU profile is a thick zone (3-4 s TWT) of relatively strong reflectivity which may characterize the lower crust of the East European platform, but is considerably shallower to the east at 8-12 s TWT (25-37 km) than in the west at 10-14 s TWT (31-43 km). Reprocessing of 20 s records from the R-17 Profile in the West Siberian basin, ~315 km northeast of the ESRU profile, reveals a similar pronounced lower-crustal reflectivity between 11-14 s TWT (34-43 km), in the hinterland of the Middle Urals. This lower-crustal reflection fabric may represent a feature developed during collisional orogenesis, or a younger property imparted through post-orogenic extension. Future deep reflection profiling will be critical to address the continuity, and accordihgly, the tectonic significance of this lower-crustal reflectivity in the Urals.
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| 2. |
- Knapp, S, et al.
(författare)
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Thermal unfolding of small proteins with SH3 domain folding pattern
- 1998
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Ingår i: Proteins. - 0887-3585 .- 1097-0134. ; 31:3, s. 309-319
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Tidskriftsartikel (refereegranskat)abstract
- The thermal unfolding of three SH3 domains of the Tec family of tyrosine kinases was studied by differential scanning calorimetry and CD spectroscopy, The unfolding transition of the three protein domains in the acidic pH region can be described as a reversible two-state process. For all three SH3 domains maximum stability was observed in the pH region 4.5 < pH < 7.0 where these domains unfold at temperatures of 353K (Btk), 342K (Itk), and 344K (Tec), At these temperatures an enthalpy change of 196 kJ/mol, 178 kJ/mol, and 169 kJ/mol was measured for Btk-, Itk-, and Tec-SH3 domains, respectively. The determined changes in heat capacity between the native and the denatured state are in an usual range expected for small proteins. Our analysis revealed that all SH3 domains studied are only weakly stabilized and have free energies of unfolding which do not exceed 12-16 kJ/mol but show quite high melting temperatures. Comparing unfolding free energies measured for eukaryotic SH3 domains with those of the topologically identical Sso7d protein from the hyperthermophile Sulfolobus solfataricus, the increased melting temperature of the thermostable protein is due to a broadening as well as a significant lifting of its stability curve. However, at their physiological temperatures, 310K for mesophilic SH3 domains and 350K for Sso7d, eukaryotic SH3 domains and Sso7d show very similar stabilities. (C) 1998 Wiley-Liss, Inc.
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