NMR of fd coat protein.

The conformations of the major coat protein of a filamentous bacteriophage can be described by nuclear magnetic resonance spectroscopy of the protein and the virus. The NMR experiments involve detection of the 13C and 1H nuclei of the coat protein. Both the 13C and 1H nuclear magnetic resonance (NMR) spectra show that regions of the polypeptide chain have substantially more motion than a typical globular protein. The fd coat protein was purified by gel chromatography of the SDA solubilized virus. Natural abundance 13C NMR spectra at 38 MHz resolve all of the nonprotonated aromatic carbons from the three phenylalanines, two tyrosines, and one tryptophan of the coat protein. The alpha carbons of the coat protein show at least two different classes of relaxation behavior, indicative of substantial variation in the motion of the backbone carbons in contrast to the rigidity of the alpha carbons of globular proteins. The 1H spectrum at 360 MHz shows all of the aromatic carbons and many of the amide protons. Titration of a 1H spectra gives the pKas for the tyrosines.     

Determination of ammonia in ethylene using ion mobility spectrometry.

A simple procedure to analyze ammonia in ethylene by ion mobility spectrometry is described. The spectrometer is operated with a silane polymer membrane., 63Ni ion source, H+ (H2O)n reactant ion, and nitrogen drift and source gas. Ethylene containing parts per billion (ppb) (v/v) concentrations of ammonia is pulled across the membrane and diffuses into the spectrometer. Preconcentration or preseparation is unnecessary, because the ethylene in the spectrometer has no noticeable effect on the analytical results. Ethylene does not polymerize in the radioactive source. Ethylene's flammability is negated by the nitrogen inside the spectrometer. Response to ammonia concentrations between 200 ppb and 1.5 ppm is near linear, and a detection limit of 25 ppb is calculated.     

A phase-corrected coupled-states approximation for inelastic scattering

A simple phase correction is derived for the coupled-states (CS) approximation based on WKB phase shifts for the electric part of the potential. The resulting phase-corrected CS (PCCS) scattering matrix agrees well in both phase and magnitude with the exact one. The PCCS approximation should then give accurate m-state information for any quantization axis.     

LEARNING FROM THE PAST：LOOKING TOWARDS THE FUTURE FOR TERTIARY CHEMISTRY IN AUSTRALIA

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Updating analytical techniques for fast neutron activation analysis

Two improvements in the analytical techniques used for fast neutron activation analysis have been developed and put into routine use. The first is neutron shielding of a NaI (TL) counting system, which reduces the counting noise encountered during neutron generation. The second is a modification of batch type irradiation for long lived nuclides so they can be done simultaneously with other test.     

Determination of calcium in waters, milk and wine by discontinuous-flow analysis

The flow-based analysis method, discontinuous-flow analysis (DFA), was used for the determination of total calcium in drinking water, milk and wine by titration with ethyleneglycoltetraacetic acid. The detector is a coated-wire calcium-selective electrode. The titration can be cycled continuously with a cycle time of about 1 min. This can be carried out with a single sample or with different samples using an autosampler. The method for waters and wine is simple, fast and highly reproducible. For milk, a back-titration method was used because of the complex matrix of the sample.     

A new class of Rh(III) catalyst containing an aminoalcohol tethered to a tetramethylcyclopentadienyl group for asymmetric transfer hydrogenation of ketones

The synthesis and application to asymmetric reduction of acetophenone, of a novel class of Rh(III) catalyst containing a tether between the cyclopentadienyl group and a homochiral aminoalcohol, is described. The complex is a highly active catalyst for asymmetric ketone reduction, however it appears to be unstable to the extended reaction conditions. The well-defined stereochemical structure of the catalyst offers potential for significant improvement and ‘fine tuning’ towards specific substrates.     

129Xe NMR spectrum of xenon inside C(60)

Xenon was inserted into C(60) by heating C(60) in 3000 atm of xenon gas at 650 degrees C. The Xe@C(60) was separated from the empty C(60) by using HPLC. The (13)C resonance for Xe@C(60) is shifted downfield by 0.95 ppm (192 Hz). (129)Xe NMR showed a line 179.2 ppm downfield from xenon gas.