Cleavage of disulfide dependent on superoxide

Disulfide bond was created by superoxide in aprotic media and by a hydroxyl radical derived from superoxide in aqueous medium. The reaction mechanism was examined in detail.     

Hall effect in intrinsic type II superconductors near the lower critical field

The Hall angle θ in three V samples (RRR = 80, 120, 140) and two Nb samples (RRR = 57, 66) has been measured in the mixed state in order to elucidate the transport properties in the intrinsic type-II superconductors with intermediate purity.     

Edge thermal transport barrier In LHD discharges

In LHD discharges a significant enhancement of the global energy confinement has been achieved for the first time in a helical device with an edge thermal barrier, which exhibits a sharp gradient at the edge of the temperature profile. Key features associated with the barrier are quite different from those seen in tokamaks: (i) almost no change in particle (including impurity) transport, (ii) a gradual formation of the barrier, (iii) a very high ratio of the edge temperature to the average temperature, and (iv) no edge relaxation phenomenon. These features are very attractive in applying the thermal barrier to future reactor grade devices.     

Magnetic moment of 48Sc

Nuclear magnetic resonances were measured for ⁴⁸Sc and ^44mSc oriented at 8 mK in an Fe host metal. The magnetic hyperfine splitting frequencies at an external magnetic field of 0.2 T were determined to be 63.22(11) MHz and 64.81(1) MHz for ⁴⁸Sc and ^44mSc, respectively. With the known magnetic moment of $\mu \left( {^{44{\rm m}}\mbox{Sc}} \right)=+3.88\left( 1 \right) \mu _N $ , the magnetic moment of ⁴⁸Sc is deduced as $\left| {\mu \left( {^{48}\mbox{Sc}} \right)} \right|=3.785\left( {12} \right)\mu _N $ . The measured magnetic moment of ⁴⁸Sc is discussed in terms of the shell model using the effective interactions.     

New small-scale cross-axis coil planet centrifuge. Partition efficiency and application to purification of bullfrog ribonuclease

The new small-scale cross-axis coil planet centrifuge (X-axis CPC) previously designed and fabricated in our laboratory has a distinctive feature such that four separation columns of similar weight are mounted symmetrically around the rotary frame to achieve stable balancing of the centrifuge under a high revolution speed. In this column layout, neighboring columns must be rotated in the opposite direction if viewed from the center of the centrifuge to avoid twisting the interconnecting flow tubes. The effect of rotational direction of the columns on the partition efficiency was evaluated with separation of a set of test samples such as cytochrome c, myoglobin, and lysozyme using an aqueous-aqueous polymer phase system composed of 12.5% (w/w) polyethylene glycol (PEG) 1000 and 12.5% (w/w) dibasic potassium phosphate under 1000 rpm of column revolution. A series of experiments was performed using a set of two diagonally located columns (connected in series) each consisting of five coiled layers of 1 mm I.D. with a total capacity of 27.0 mL. Both right- and left-handed coils were tested each under the optimized conditions for choice of mobile phase and direction of the column rotation so that the satisfactory volume of the mobile phase was retained in the column by the aid of Archimedean screw effect. The results of these studies showed that one particular combination of handedness of the coil and direction of the rotation yielded the best peak resolution for each mobile phase. In order to demonstrate the capability of the apparatus, the purification of ribonuclease (RNase) from the extract of bullfrog egg, sialic acid binding lectin (cSBL), was carried out using both organic-aqueous and aqueous-aqueous polymer phase systems. When using the 16.0% (w/w) PEG 1000-6.3% (w/w) dibasic potassium phosphate-6.3% (w/w) monobasic potassium phosphate system, cSBL was successfully separated from other proteins present in the extract while commercial RNase A was eluted at near the solvent front by the lower phase mobile. The cSBL retained its native RNase activity. The overall results demonstrated that the present new small-scale X-axis CPC is useful for the purification of bioactive compounds without loss of their native activities.     

Efficient proton conduction in dry nanofilms of amorphous aluminosilicate

Amorphous aluminosilicate nanofilms as prepared by a sol-gel process and post-annealing exhibit proton conduction at a wide temperature range in dry air with a lowest area specific resistance of 0.24 omega cm2 at 400 degrees C.     

Embedding of individual ferritin molecules in large, self-supporting silica nanofilms

We report herein the fabrication of ferritin-embedded self-supporting silica nanofilms via a simple spin-coating process. Ferritin was employed as a template molecule, and solutions of ferritin and silica were spread on a polymer-coated silicon substrate, in this order. After dissolving the polymer underlayer by simply immersing ethanol, a centimeter-sized self-supporting nanofilm of ferritin/silica composite with a thickness of 15 nm was successfully transferred onto an alumina membrane without the film breaking. Ozone and hydrochloric acid solution treatment removed the template ferritin molecules from the composite film to produce corresponding transmembrane nanoholes. The reported method is very simple, and the fabrication of a protein-embedded self-supporting nanofilm enables the design of biomembrane-mimetic devices.     

Polarized beam of unstable nuclei via ion beam surface interaction at grazing incidence

We have measured the polarization of unstable nuclei produced by the technique of ion beam surface interaction at grazing incidence (IBSIGI). A 60 keV ¹²⁴Cs beam from the on-line mass separator was used. The NMR technique was employed for the observation of the nuclear polarization. A small polarization of 0.22(13)% was observed. The small value was interpreted in terms of the velocity dependence of nuclear polarization, comparing with the results observed with stable nuclei. This revised version was published online in August 2006 with corrections to the Cover Date.