Shock structure deformation in plasma jet caused by strong magnetic field

The shock structure deformation in a plasma jet caused by a strong magnetic field was studied using an optical method. The plasma jet images in the enclosing vacuum chamber were taken with a digital single-lens reflex camera through a viewing window. Since the relative values of the measured light intensity are known to have a strong correlation with the number density of excited atoms, the vertical distribution of light intensity can be converted to a radial distribution of excited atom density using an Abel-inversion. The results of this conversion with a magnetic field were compared in the present experiments with those without the presence of a field. It is possible to obtain a smooth radial distribution of estimated number density using an approximate line. The density along the centerline increases obviously with the magnetic field. The minimal density point around the Mach disk was moved slightly upstream with the application of the field. The density distribution inside of the jet boundary was changed considerably by the application of the strong field. The jet boundary itself was not found to be affected significantly by the field although the boundary was found to be slightly contracted to the center axis with application of the field. It has been confirmed that the density distributions are mainly affected by the magnetic field at the corresponding location.     

Gene transfer of human prostacyclin synthase prevents neointimal formation after carotid balloon injury in rats

BACKGROUND AND PURPOSE: A disordered proliferative process in the vascular wall is thought to underlie the pathogenesis of restenosis after percutaneous transluminal angioplasty and carotid endarterectomy. A growth inhibitory property of overexpressed prostacyclin (PGI2) synthase (PGIS) was recently implicated in the pathological proliferation of vascular smooth muscle cells (VSMC) in vitro. Here, we investigated the effects of increased PGI2 synthesis on the pathological proliferation of VSMCs. METHODS: The cDNA encoding human PGIS was transfected into endothelium-denuded rat carotid arteries after arterial balloon injury with the use of hemagglutinating virus Japan (HVJ). HVJ liposome vector complex without PGIS cDNA was used for vehicle control. The level of 6-keto PGF1alpha, a stable hydrolyzed metabolite of PGI2, the histological distribution of the immunoreactivity for human PGIS and the ratio of neointimal/medial area were analyzed. RESULTS: In the analyses of 6-keto PGF1alpha, the level in the carotid arteries was significantly elevated 3 days after PGIS expression-vector transfection compared with that in the arteries after vehicle transfection. Seven days after human PGIS expression-vector transfection, the PGIS cDNA-transfected neointimal cells were strongly positive for human PGIS immunoreactivity in 81% sections examined. Fourteen days after the injury, the ratio of neointimal/medial area was 1.2+/-0.4 in the PGIS expression-vector transfected group, which was significantly smaller than that of the vehicle control group, 1.7+/-0.5; P<0.01. CONCLUSIONS: It was thus demonstrated that the gene transfer of human PGIS expression-vector into rat carotid arteries resulted in the increased production of human PGI2 in the vascular wall, the expression of human PGIS in the developing neointima and significantly inhibited the neointimal formation generated after balloon injury.     

Presumptive technique of power generation of amorphous silicon cell including various factors

This paper describes the presumptive technique of power generation of amorphous silicon module considering various factors. The influences exerted by solar spectrum, spectral response, angle of incidence and efficiency deviation are evaluated. Then, various factors are formulated. The presumptive technique of power generation including these factors is examined. As a result, the proposal technique is able to presume with a high accuracy as compared with the conventional technique.     

Growth of Fe3O4 whiskers from solid solution nanoparticles of Fe–Cu and Fe–Ag systems produced by DC plasma jet method

Fe–Cu and Fe–Ag binary systems are virtually immiscible for a whole range of composition in equilibrium. In the present study, the nanoparticles of Fe–Cu and Fe–Ag systems were produced by direct current plasma jet method. These produced nanoparticles had mean particle sizes of about 70 nm, and were a mixture of bcc and fcc phases. It was revealed by analytical high-resolution TEM observations that the nanoparticles of Fe–Cu and Fe–Ag systems were supersaturated solid solution. It has been found that numerous whiskers with a particle on their tip grow from these nanoparticles by heating above the temperature of 860 K under an Ar–O₂ atmosphere. The whiskers grow as the result of the phase separation in these solid solutions. The whiskers are composed of a Fe₃O₄ rod and a Cu₂O particle on the tip.     

Measurement of the magnetic characteristics of oriented silicon steel in an arbitrary direction

The measurement method and the experimental results on the magnetic characteristics of oriented silicon steel in any direction are described in this paper. A single sheet tester of rotational loss has been used in order to simulate conditions existing in real devices. The flux of any direction is induced in the specimen by exciting from X and Y directions in the same phase. The flux density was measured by each search coil. The magnetizing force was measured by the double H-coil method. The outputs of the B-coils and the H-coils were treated by sending the outputs from the wave digitizer to the personal computer. The components of the magnetic characteristics in the X and Y directions for small values of B are the same. Only the saturation value changes, and it depends on the direction of flux.     

Insulin-stimulated GLUT4 translocation is relevant to the phosphorylation of IRS-1 and the activity of PI3-kinase

We examined the role of 185-kDa insulin receptor substrate-1 (IRS-1) and phosphatidylinositol 3-kinase (PI3-kinase) in the signaling pathway of insulin-stimulated GLUT4 translocation. We had already developed a novel cell line to detect GLUT4 on the cell surface, directly and sensitively (Kanai, F., Nishioka, Y., Hayashi, H., Kamohara, S., Todaka, M., and Ebina, Y. (1993) J. Biol. Chem. 268, 14523-14526). We stably expressed a mutant insulin receptor in which Tyr972 was replaced with phenylalanine. Insulin-stimulated tyrosyl phosphorylation of IRS-1 and GLUT4 translocation were decreased in cells expressing the mutant receptor, as compared to findings in cells expressing the normal receptor. Wortmannin, an inhibitor of PI3-kinase, inhibits the insulin-stimulated PI3-kinase activity and GLUT4 translocation at 50 nM, but not the NaF-stimulated GLUT4 translocation. These results suggest that the tyrosine phosphorylation of IRS-1 and activation of PI3-kinase may be involved in the signaling pathway of the insulin-stimulated GLUT4 translocation.     

Arsenic extraction from solid phase using a dissimilatory arsenate-reducing bacterium

We investigated the feasibility of a novel bioremedial strategy for arsenic-contaminated soil using a dissimilatory arsenate-reducing bacterium (DARB), Bacillus sp. SF-1. SF-1 was able to effectively extract arsenic from various arsenic-laden solids, via the reduction of solid-phase arsenate to arsenite, which is much less adsorptive than arsenate. The strain can be an easy-to-handle, and cost-effective bioremedial agent.     

Improvement of chromatic aberration of a plastic rod lens array. 1. Combination-color lens arrays consisting of several kinds of rod lenses with different gradient constants and different color filter functions

We propose a new type of rod lens array with improved chromatic aberration. The new rod lens array consists of several kinds of rod lenses with different gradient constants and different color filter functions. The gradient constant of each lens was prepared such that the total conjugate length was identical to the specific wavelength of the lens with a constant lens length. We call our new type of rod lens array a combination-color lens array. The characteristics of this color-type lens array are as follows: high angular aperture, short focal length, and ease of production with established procedures. The optical resolution of the rod lens array is 300 dpi in a wide wavelength range that is high enough to be applied to color scanners.