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Abstract: Here we present the crystal structure of Importin-β(1–462)·Ran·GTP·RanBD1ΔN as solved by molecular replacement. HPLC dissociation measurements on this complex show, that the N-terminus of RanBD may be involved in the release of the hydrolysis- and dissociation-block of Ran by Transportin/Importin-β. We could identify a pair of amino acids which – upon mutation – weaken the interaction between Ran and Importin-β specifically to allow dissociation without RanBD. These findings support the hypothesis that a ternary complex of Importin-β·Ran·GTP·RanBD exists in the final step of the export of Importin-β from the nucleus and that interaction of the N-terminus of RanBD with Ran plays a crucial role in disassembly of this complex. [Copyright &y& Elsevier]

Abstract: We report on the continuous increase of the breakdown electric field, also known as disruptive strength, of an ultra thin layer based on Al2O3 prepared by low temperature atomic layer deposition (ALD) by reducing its thickness down to 3nm. By measuring the disruptive strength for lower thicknesses, we demonstrate that these observations are in agreement with recent reports. Furthermore we detected an increase within the disruptive strength towards lower thicknesses together with a rise of the pin hole density. The pin holes, originating from an inhomogeneous growth of the dielectric and referred to as morphological defects and current conducting paths, are detected by Cu electroplating and result in a lower permittivity of the dielectric. As a conclusion, the dielectric breakdown of thin, low temperature ALD processed Al2O3 layers does not seem to be negatively influenced by the increase of the pin hole density. Thus, the increase of the disruptive strength is either due to the morphological defects in the form of pin holes or a material phenomenon that is not affected by its nanoporous structure. [Copyright &y& Elsevier]