Effects of vitamin B6 deficiency on cytokine levels and lymphocytes in mice

The effects of vitamin B6 (B6) deficiency on cytokine levels and proportions of lymphocyte subsets in BALB/c mice were investigated. The proportion of lymphocytes from the thymus and spleen of mice given no B6, that were CD4+ CD8- T cells, was larger than in mice given B6, and the ratio of CD8+ to CD4+ T cells in the thymus of mice given no B6 was lower. The concentrations of interleukin-5 and -10 in spleen cells stimulated in vitro with concanavalin A were significantly higher in the mice with B6 deficiency, as was their plasma corticosterone concentrations. These results suggested that B6 is necessary to maintain cytokine levels and lymphoid function in the thymus and spleen of mice.     

Automatic optical inspection of plated through-holes for ultrahigh density printed wiring boards

An automatic optical through-hole inspection system for ultrahigh density printed wiring boards (PWBs) using leakage light detection has been developed. To detect the dim leakage light emitted from the through-hole defect, we enhanced the sensitivity of the light detector 150 times using a microchannel plate tube. However, the tube caused two problems: stray light sensing and image distortion. To solve these problems, we optically isolated the sensing optics and developed a distortion correction method. We have developed a prototype system that can detect a defect as small as 100 m.     

Co-crosslinking blend of incompatible polymers VI: Poly(vinyl chloride) toughened with polyethylene via a co-crosslinking technique

A binary blend which consists of two incompatible polymers such as poly(vinyl chloride) and polyethylene has been performed through a partial co-crosslinking reaction with peroxide to give a co-crosslinked blend with a uniform dispersion of small polyethylene particles and with an improved mechanical property. The results are obtained through the formation of a co-crosslinked product which acts as a potential solid phase dispersant as well as a well-bonded reinforcing interlayer on polyethylene particles uniformly dispersed in poly(vinyl chloride) matrix. The resulting blends (PVC/PE=10/90 wt) give carbon spherules of 0.5 to 1m diameter through pressure-carbonization at 650° C for 1 h.     

Surface modification of tetrafluoroethylene–perfluoroalkyl vinylether copolymer (PFA) by plasmas for copper metallization

Tetrafluoroethylene–perfluoroalkyl vinylether copolymer (PFA) sheet surfaces were modified with argon, helium, oxygen, and hydrogen plasmas. How the four plasmas modified the PFA sheet surfaces was investigated. All plasmas modified the PFA surfaces and at the same time initiated degradation of the PFA polymer chains. The balance between modification and degradation was strongly influenced by the magnitude of the discharge current in the plasmas. Efficiency of the plasmas in modification was hydrogen plasma > oxygen plasma > argon plasma > helium plasma. The modification involved defluorination of CF₂ carbons into CHF and CH₂ carbons and oxidation into O? CH₂, O? CHF, and O? CF₂ groups. The surface‐modification technique (a combination of hydrogen plasma treatment and silane coupling treatment) proposed in this study was applied for copper metallization of the PFA surface. The utility of the technique was confirmed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1087–1097, 2002     

Microstructure of carbon spherules

Carbon spherules were formed from a mixture of polyethylene with 5–10 wt% Polyvinylchloride under pressure of 30 MPa. The spherules were embedded in a resin and thin-sectioned with a diamond knife. Alignment of small aromatic layers in the spherules was studied by transmission electron microscopy using dark-field image and microdiffraction techniques. Based on the obtained dark-field images at various positions of the aperture on the 002 diffraction ring, a structural model for the as-prepared spherules has been proposed. In this model small aromatic layers are assumed to align approximately on circular conical surfaces with a common vertex in the spherule at or near the center of the spherule. The proposed model is supported by an electron microdiffraction study of various micro-areas of sections of the spherules. The model is also consistent with the deformation of spherules into thick disks and formation of a definite system of cracks in heat-treatment to 2800°C as revealed by scanning electron microscopy.     

Effects of functional groups in glow discharge polymerization

Summary Glow discharge polymerizations of allyltrimethylsilane (ATMS) and trimethylvinyloxysilane (TMVOS) were investigated by elemental analysis and infrared spectroscopy. The formed polymers were far different in elemental composition from the starting materials, and possessed high carbon and hydrogen contents. There was less difference in an infrared-spectral sense between the two polymers from ATMS and TMVOS. A polymer-forming process in a discharge state is discussed.     

Role of unsaturated groups in glow discharge polymerization

The role of unsaturated groups of the starting compounds in glow discharge polymerization was investigated by elemental analysis, infrared spectroscopy, and ESCA. Tetramethylsilane (TMS), trimethylvinylsilane (TMVS), and ethyltrimethylsilane (ETMS) were used as starting materials. Glow discharge conditions (W/FM value meaning the rf power input per mass of the monomers) as well as a degree of the unsaturation of the starting materials had strong influences upon the polymer deposition rate and the elemental composition of the formed polymers. The C_1s and the Si_2p spectra showed that the chemical composition of these polymers was distinguished by either presence or absence of the unsaturated groups in the starting compounds rather than kind of the unsaturated groups. The polymer formation, when the monomers containing double and triple bonds were served, is proceeded not only through these unsaturated bonds but also through the cleavage between Si and C atoms.     

Hydrophilic surface modification of polypropylene films by CCl4 plasma

The CCl₄ plasma treatment of polypropylene films was investigated from the viewpoint of hydrophilic surface modification using a contact-angle meter, ATR FTIR spectroscopy, and angular XPS. Hydrophilicity and chemical composition of the CCl₄ plasma treatment was effective in hydrophilic modification. The advancing contact angle of water for polypropylene films was decreased from 99° to 81-7° by the CCl₄ plasma treatment, and the surface energy increased from 27.2 to 38.9-67.7 mJ/m² when the discharge current varied from 50 to 150 mA. The CCl₄ plasma initiated chlorination, oxidation, and aluminum sputtering reactions. The chlorination of polypropylene films was favorable in a mild CCl₄ plasma operated at discharge current of 50 mA. The oxidation and aluminum sputtering reactions were predominant over the chlorination in strong CCl₄ plasmas operated at discharge currents of more than 75 mA. The chlorination initiated by the mild CCl₄ plasma was restricted near the film surface within 36 Å deep. The regions modified with the strong CCl₄ plasma reached inner layers of 36-49 Å deep. Hydrophilicity caused by the CCl₄ plasma treatment may be due not only to chlorine functionalities but also to oxygen and aluminum functionalities. © 1993 John Wiley & Sons, Inc.     

Changes in pore properties of phenol formaldehyde-based carbon with carbonization and oxidation conditions

Porous carbon beads were prepared by carbonizing at 700 and 1000 °C under N₂ (NN-series) or CO₂ atmospheres (CO-series) and a subsequent oxidization with boiling nitric acid solution (13%, v/v) for 3 h (ANN- and ACO-series). BET surface area of both CO- and NN-series samples tends to increase with increasing carbonization temperature, but CO-series samples show higher BET surface areas (700 °C: 610 m²/g, 1000 °C: 780 m²/g) compared with those of NN-series samples (700 °C: 380 m²/g, 1000 °C: 580 m²/g). After acid oxidation, BET surface areas of NN-series samples increased from 580 to 650 m²/g, whereas those of CO-series samples decreased from 780 to 600 m²/g. On subsequent acid oxidation, acidic surface functional groups increased in both CO- and NN-series samples, but the CO-series samples tend to have much more acidic surface functional groups. Adsorption of halogenated methanes, such as tetra-, tri- and dichloromethanes, onto the samples of CO-, NN-, ACO- and ANN-series was thought to be driven initially by the basicity, but the acidic functional groups that could attract adsorbates via dipole-dipole interaction might hinder the adsorption of subsequently incoming adsorbates.