Crystallization of Arthrobacter sp. strain 1C N-(1-D-carboxyethyl)-L-norvaline dehydrogenase and its complex with NAD+

The novel NAD+-linked opine dehydrogenase from a soil isolate Arthrobacter sp. strain 1C belongs to an enzyme superfamily whose members exhibit quite diverse substrate specificites. Crystals of this opine dehydrogenase, obtained in the presence or absence of co-factor and substrates, have been shown to diffract to beyond 1.8 ? resolution. X-ray precession photographs have established that the crystals belong to space group P21212, with cell parameters a = 104.9, b = 80.0, c = 45.5 ? and a single subunit in the asymmetric unit. The elucidation of the three-dimensional structure of this enzyme will provide a structural framework for this novel class of dehydrogenases to enable a comparison to be made with other enzyme families and also as the basis for mutagenesis experiments directed towards the production of natural and synthetic opine-type compounds containing two chiral centres.     

Wire number doubling in high-wire-number regime increasesZ-accelerator X-ray power

Doubling the number of tungsten wires from 120 to 240, keeping the mass fixed, increased the radiated X-ray power relative to the electrical power at the insulator stack of the Z accelerator by (35±15)% for 8.75- and 20-mm radii Z-pinch wire arrays. One-dimensional radiation magneto hydrodynamic calculations suggest that the arrays were operating in a quasi “plasma-shed” regime, where the plasma generated by the individual wires partially merge prior to the inward implosion of the entire array     

Double Z-pinch hohlraum drive with excellent temperature balance for symmetric inertial confinement fusion capsule implosions

A double Z pinch driving a cylindrical secondary hohlraum from each end has been developed which can indirectly drive intertial confinement fusion capsule implosions with time-averaged radiation fields uniform to 2%-4%. 2D time-dependent view factor and 2D radiation hydrodynamic simulations using the measured primary hohlraum temperatures show that capsule convergence ratios of at least 10 with average distortions from sphericity of /r200 MJ.