Water-Soluble contrast enhancing materials—new photobleachable dyes

Many styrylpyridinium compounds (SPC), which are very stable in the dark, were prepared and evaluated as photobleachable dyes for contrast enhanced lithography (CEL). The photobleaching characteristics of water-soluble contrast enhancing materials composed of SPC and water-soluble polymer depend on the structure of the SPC and the kind of polymers used. The technique using SPC-based CEL proved to be very effective for the resist pattern profiles.     

STM spectroscopy in superconducting phase of (BEDT-TTF)2Cu(NCS)2

The superconducting phase of (BEDT-TTF)₂Cu(NCS)₂ was investigated with use of the scanning tunneling microscope (STM).The tunneling conductance was measured at the b-c surface of a single crystal. The differential conductance shows a clear superconducting gap structure below the transition temperature and its value is reduced to almost zero around zero bias voltage at 1.9 K. The conductance curve is not well fitted to the BCS one but suggests the gap anisotropy. However, the gap with line nodes, expected from the simple d-wave symmetry, is excluded. Possible models for the superconducting gap are as follows; (1) the gap with point nodes or (2) the anisotropic gap with a minimum value Δ_min1 mev. It is understood that the superconducting gap is highly anisotropic in k-space.     

Time domain measurements of launching-condition-dependent bandwidth of all-plastic optical fibres

The dependence of the -3 dB bandwidth of an all-plastic optical fibre (APF) on the launching conditions was measured using the time domain method with a visible-light laser diode as the light source. The launch optics and detector appropriate to APFs were examined. The bandwidth was observed to have a large dependence on the launching conditions.<>     

Relationships between the hepatic intrinsic clearance or blood cell-plasma partition coefficient in the rabbit and the lipophilicity of basic drugs

We investigated the delivery of foreign genes into mouse glioma cells in vivo using hemagglutinating virus of Japan (HVJ)-liposomes, which are coated by Sendai virus envelope protein. HVJ-liposomes, containing lacZ gene or herpes simplex virus thymidine kinase (HSVtk) gene-bearing plasmid DNA were applied in the meningeal gliomatosis (MG) mouse model system. Highly efficient delivery was observed in disseminated glioma cells, and 80% of MG mice expressing the HSVtk gene were cured by treatment with ganciclovir. These results suggest that this novel gene delivery system may be applicable for the in vivo gene therapy of human malignant glioma.     

The oxidation kinetics of spherically shaped palladium powder

The oxidation kinetics of spherically shaped palladium (Pd) powders was investigated over the temperature range between 350 and 800°C. Two types of Pd powders differing from each other in particle sizes were used in this study, 0.30 and 0.85 m in diameter. The fraction of total oxide formed was measured in situ by means of a thermobalance method. In this system, the volume of product palladium oxide (PdO) increases significantly vs. the volume of reactant Pd, and consequently the experimental data were explained well by Valensi-Carter equation. Apparent activation energies of oxidation for the two types of Pd powders were both estimated to be 140 kJ/mol.     

Highly-sensitive and high-resolution all-fiber three-dimensional measurement system

A practical all-fiber three-dimensional measurement system is demonstrated with an incoherent interferometer at the eye-safe wavelength of 1.55 mum. The sensitivity and axial resolution are as high as 102 dB and 1.4 mum from a few meters' distance, respectively. A rotating scanner is developed for axial scanning, and a wide longitudinal scanning range of 54 mm is demonstrated. The high resolution images of a few samples are clearly obtained at the speed of 52 points/s. Moreover, the resolution, sensitivity, speed, and angle dependence are discussed for measurement of a 100 yen Japanese coin.     

The effect of copper(II) on the formation of γ-FeOOH

Various γ-FeOOH samples have been synthesized by air oxidation of FeSO₄ solution with or without addition of Cu(II) (0–46 at.%Cu/Fe) and examined by X-ray diffraction, electron-microscopic observation, BET surface area determination, infra red absorption, DTA and chemical analyses. A destructive action of doped Cu(II) ions on the crystal formation was apparently recognized and discussed based on the crystallographic structure. The possible mechanism of crystallization of γ-FeOOH appears to differ between pure and Cu-doped γ-FeOOH, particularly one containing nearly 50%Cu.     

C NMR study of C-enriched single-wall carbon nanotubes synthesized by catalytic decomposition of methane

¹³C NMR spectra and spin-lattice relaxation times were measured for single-wall carbon nanotubes with 99.9 and 50.0% ¹³C enrichments and natural abundance (1.1% ¹³C) prepared by catalytic decomposition of CH₄. The ¹³C isotropic shift is about 116 ppm from tetramethylsilane, being estimated from magic-angle-spinning (MAS) spectra. The value does not depend on the degree of the ¹³C enrichment. The ¹³C MAS NMR spectra show two additional small peaks at 171 and 152 ppm, which are ascribed to carbon species at defects or edges. The line widths of the main isotropic peak in MAS spectra are about 30 ppm, the origin of which is mostly chemical shift dispersion, reflecting a distribution of diameter and helicity. The line width in the ¹³C static spectra originates from chemical shift dispersion, chemical shift anisotropy and dipole–dipole interactions between ¹³C spins as well as between ¹³C and ¹H spins at defects or edges. ¹H NMR spectra confirm the presence of H-containing species. The ¹³C spin-lattice relaxation is dominated presumably by interaction with magnetic impurities.