[en] Hydration of amides in aqueous solutions has been studied by measuring the infrared spectra of amides (benzamide, p-methoxybenzamide, and ropionamide) in dioxane-D₂O and dioxane-H₂O mixtures. The absorption due to the C=O stretching (or amide I band) exhibited a very remarkable red shift accompanied by a characteristic change of the band shape as the water content in the medium increased. The spectral change is attributed to the change of the hydration state at the carbonyl oxygen. In the aqueous mixtures, amide molecules participate in an equilibrium among various states of hydration. The weighted mean frequency of the ν/sub C = O/ absorption, anti ν/sub C = O/, varied in proportion to the water contained in the medium. The difference between the anti ν/sub C = O/ value in pure water and that in pure dioxane,Δ anti ν, was used as a measure of the maximum degree of hydration. It was larger for propionamide than for the aromatic amides, suggesting that the steric effect of the substituents is of major importance in hydration. The isotope effect, Δ anti ν/sub D₂O//Δ anti ν/sub H₂O/, in the range from 1.4 to 1.6 for all cases examined, indicated that stronger hydration of amides occurred with D₂O than with H₂O

[en] The early history of neutrino mixing will be discussed with a focus on the birth of the MNS theory

[en] This report includes feasibility studies for a new synchrotron radiation source using TRISTAN Main Ring (MR) of KEK now being used as an electron and positron collider. A task force for the feasibility study started in the spring of 1990, and a sub-group was organized to study and discuss the problems related to the lattice of MR. The main subject in this report is how to realize both very small emittance and large dynamic aperture in a new lattice. Two long straight sections in the present lattice called 'Nikko' and 'Oho' must be modified like a gable roof, 1) to get free space for insertion devices, 2) to extract their synchrotron radiation to the experimental hutches which will be set in the ring tunnel in those sections and 3) to add a radiation shielding wall between the ring and the beam channel for the synchrotron radiation. The other two long straight sections called 'Fuji' and 'Tsukuba' will be used for injection, RF cavities and damping wigglers necessary for the very low emittance. The ultimate emittance will be 1.6 nm rad with the horizontal dynamic aperture of 36 x 10^-6 m rad that is about half the aperture experienced at the present MR. (author)

[en] Rat phospholipase D was successfully solubilized with Triton X-100. Solubilized phospholipase D is clearly separated from phosphatidic acid phosphatase and still dependent on sodium oleate for activity

[en] The results are reported of the neutron activation analysis of poly(methyl methacrylate) polymerized with a redox system of chromium (II) acetate and p-chlorobenzyl peroxide in dimethylformamide at 30⁰C. Since the polymer was originally synthesized in experiments for kinetic studies, the results indicate an arbitrary background of purity of polymers obtained in a laboratory. Samples were irradiated for 28m and gamma spectra detected trace amounts of chlorine, aluminum, vanadium, magnesium, manganese, potassium, copper, zinc, sodium, bromine, lanthanum, gold, and chromium. 2 figures, 1 table

[en] A design for admitting cesium vapor into a hollow hydrogen plasma discharge in a duoplasmatron ion source for the purpose of increasing the negative hydrogen ion output current is described. 60 mA beam currents for negative hydrogen ions are reported

[en] To study the change in vortex dynamics associated with the change in equilibrium vortex states from the thermal to quantum-vortex-liquid (QVL) upon cooling, we have performed measurements of the fluctuating [time (t)-dependent] component of flux-flow voltage V(t), δV(t)≡V(t)-V₀, about the average voltage V₀ using a thick amorphous Mo_xSi_1-x film. Only in the QVL phase, large δV(t) is observed. The distribution of δV(t) is asymmetric having a tail along the direction of flux motion [δV(t)>0], suggesting the presence of anomalous flux-flow motion in the QVL phase

No abstract available

[en] The protective effect of glutathione (GSH) and cysteamine (MEA) on radiation-induced mitotic delay in cultured mammalian L-5 cells was studied. Cells treated with 20 mM of GSH during irradiation with 2 Gy (200 rad) showed faster recovery of the mitotic index than control cells irradiated without chemical treatment; however, GSH had no effect on mitotic delay time. Inhibition of mitosis was observed with 80, 100, and 120 mM of GSH. Cells treated with 5 mM of MEA during irradiation also showed faster recovery of the mitotic index than the controls, but in addition the delay time was shortened. Progression of G₂-phase cells treated with 5-fluorouracil to mitosis after irradiation was protected by MEA but not by GSH. Progression of S-phase cells labeled with ³H-thymidine to mitosis was accelerated by both agents during irradiation

[en] We measure the ac complex resistivity in the mixed state of amorphous Mo_xSi_1-x films with different thicknesses (t). For films with t=100 and 30 nm we can determine the vortex-glass-transition (VGT) line which persists down to low temperatures (T) up to high fields (B) near the upper critical field at T=0. In the liquid phase the vortex-relaxation time (τ_g) extracted from the frequency dependence of ac resistivity follows the power-law T dependence expected by the VG theory for three dimensions (3D). For the thinner (10, 6 nm) films, both the dc resistivity and τ_g follow the activated T dependence except for the very low-T region, suggestive of 2D VGT. For all of the films studied, τ_g in high B shows a decreased T dependence at lower T, indicating the quantum-driven fluctuations