Optical emission spectroscopic study for diagnostics in high gravity DC-plasma CVD diamond growth

The effect of gravity on materials processing is rather complicated, and a large number of considerably unexpected results due to high gravity or sometimes centrifugation have been reported. The authors have been conducting high gravity diamond thin film growth by the DC-plasma CVD method up to 100 G. The effects of high gravity appeared in the nucleation site density, growth rate, grain size, uniformity, film coverage and morphology. With the increase in gravity, the nucleation site density, growth rate, grain size were all found to be increased, the uniformity and film coverage were improved, and {100} facet became dominant rather than {111} facet. To understand the deposition mechanism in these effects observed in high gravity, a diagnostic apparatus for spectroscopic study of the optical emission from the DC-plasma was developed, and the OES (optical emission spectroscopy) apparatus has been employed in high gravity CVD experiments. The influence of gravity on the most active species in the plasma, such as H, CH, C₂ was discussed together with the results from the Raman spectroscopy and X-ray diffraction study.     

Synthesis and Properties of Novel Poly(p-phenylenevinylene)s Containing a Tricarbonyl(arene)chromium Unit in the Main Chain

Summary Novel π-conjugated polymers based on poly(p-phenylenevinylene)s (PPVs) containing a tricarbonyl(arene)chromium unit in the main chain were synthesized by Horner-Wadsworth-Emmons olefination. The structures of the polymers were supported by ^lH NMR and IR spectra. The polymers obtained were soluble in common solvents such as THF, CH₂Cl₂, CHCl₃ and toluene. The molecular weights of the polymers were determined by GPC. Their thermal, optical, and electrochemical properties were investigated in detail. Received: 18 November 2002/Revised version: 10 February 2003/ Accepted: 11 February 2003 Correspondence to Yoshiki Chujo     

A monolithic1 x 10array of InGaAsP/InP photodiodes with small dark current and uniform responsivities

We fabricated a monolithic 1 × 10 array of InGaAsP/InP double-heterostructure photodiodes by liquid-phase epitaxy, which has highly uniform characteristics in breakdown voltages and responsivities and whose deviations in an array are ±1 percent and ±6 percent, respectively. The dark current of the elemental photodiode at low bias voltage, which is attributed mainly to the generation-recombination process in the depletion layer, is smaller than that of the germanium avalanche photodiode by one order at room temperature. The elemental photodiodes in the array have high quantum efficiency of more than 60 percent with SiOxfilm for antireflection in a wavelength range of1.0-1.2 mum, fast response time shorter than 1 ns, and very high cutoff frequency of about 800 MHz with the load resistance of 50 Ω.     

Simple thermo-level meter for HeI and HeII by a dynamic method

A simple liquid helium level monitoring device has been developed using pairs of carbon resistors mounted on a stainless steel ‘dipstick’. The device described has a resolution of 50 mm and negligible power dissipation. The level of both superfluid and normal helium, and the liquid temperatures, can be determined. The device has no moving parts and after some years of use has proved to be sturdy and durable. A similar device is proposed with a resolution of 12 mm and a microcomputer data recording system.     

Cytokine regulation of cell-to-cell interactions in lymphokine-activated killer cell cytotoxicity in vitro

The permanent pancreas carcinoma cell line, PCI-24, was developed in order to analyse cytokine regulation on pancreas carcinoma and lymphokine-activated killer (LAK) cell interaction. PCI cells expressed ICAM-1 and HLA-ABC, but not HLA-DR antigens. PCI cells showed augmented ICAM-1 and HLA-ABC expression when incubated with interferon gamma (IFN gamma) and tumour necrosis factor alpha. A similar but weak augmentary effect on the HLA-ABC and ICAM-1 surface expression was seen with interleukin-1 beta treatment. Natural attachment of LAK to PCI cells was augmented by recombinant IFN gamma in close association with ICAM-1 up-regulation on PCI cells. In addition, natural attachment was significantly inhibited by anti-LFA-1 and anti-ICAM-1 antibody treatments. Cytotoxicity of the LAK cells against PCI cells was also significantly inhibited with the same treatment. Thus, the attachment of LAK cells to PCI cells through LFA-1/ICAM-1 molecules appeared to be essential for the cytotoxicity for PCI cells. Pretreatment of PCI cells, but not of LAK cells, with IFN gamma or other cytokines resulted in a decrease of susceptibility for LAK cell cytotoxicity. The decreased susceptibility inversely correlated with HLA-ABC expression on the PCI cells. The collective evidence indicates that, although LAK cell attachment to pancreas carcinoma cells through the LFA-1/ICAM-1 molecule is augmented by IFN gamma, IFN gamma treatment of pancreas carcinoma cells reduces LAK cell cytotoxicity possibly through an increase in HLA-ABC or a regulation of molecules closely associated to HLA-ABC expression.     

Analysis of restriction fragment length polymorphism for the HLA-DR gene in Japanese patients with sarcoidosis

BACKGROUND: It is commonly assumed that some immunological disorder may play a part in the pathogenesis of sarcoidosis. Previous studies by several groups have shown a significant association with HLA-DR antigens in patients with sarcoidosis. In this study, restriction fragment length polymorphism (RFLP) analysis of the HLA-DR gene was designed to confirm the association at the gene level and to look for a gene rearrangement which may influence susceptibility to sarcoidosis. METHODS: Thirty two unrelated Japanese patients with sarcoidosis were tested for HLA antigens and subjected to RFLP analysis after digestion with Eco RI, Pst I, Bam HI, Pvu II, and Hind III by using an HLA-DR beta cDNA probe. A group of 47 unrelated healthy Japanese subjects served as controls. Frequencies of each restriction fragment were compared between the patients and the control subjects. Correlation between fragment frequencies and clinical features were also analysed. RESULTS: No restriction fragments of HLA-DR beta gene were found specific to the patients with sarcoidosis. The RFLP analysis could detect polymorphism of HLA-DR beta genes that was not distinguishable by conventional serological methods. Several restriction fragments of the DR beta gene were seen only in DRw52 positive individuals, and showed higher frequencies in the patients than in control subjects. The patients with these DNA fragments were likely to have limited stage disease with no ophthalmic involvement. CONCLUSIONS: An association between HLA and sarcoidosis was noted at the DNA level, although no restriction fragments were specific for this disease. RFLP analysis of the HLA gene is a more useful method than the usual HLA typing, and should be the first step in identifying the gene sequence which is connected with susceptibility to sarcoidosis.