Accuracy of treadmill exercise electrocardiography in detecting restenosis following single-vessel percutaneous transluminal coronary angioplasty

To develop an improved method for diagnosing restenosis using treadmill exercise electrocardiography (ECG) following percutaneous transluminal coronary angioplasty (PTCA), we prospectively evaluated 46 patients who underwent PTCA for the treatment of single-vessel coronary artery disease and who did not have a history of myocardial infarction. Treadmill exercise ECG and coronary angiography were performed 3 months after PTCA to determine their accuracy in diagnosing restenosis based on standard ST-segment depression criteria, the difference between the maximum ST-segment depression before and 3 months after PTCA (< or =0.5 mm: positive; >0.5 mm: negative), and the difference between sigmaST-segment depression before PTCA and 3 months after PTCA (< or = 1.5 mm: positive; > 1.5 mm: negative). The sensitivity, specificity, and diagnostic accuracy of standard ST-segment depression criteria were 65%, 66%, and 65%, respectively. The sensitivity, specificity, and accuracy for the difference in maximum ST-segment depression were 77%, 76%, and 76%, respectively, whereas the values for the difference in sigmaST-segment depression were 77%, 83%, and 80%, respectively. Based on these results, we conclude that using the difference between ST-segment depression before and after PTCA improves the accuracy of treadmill exercise ECG for diagnosing restenosis.     

Antitumor response of genetically engineered IL-2 expression to human esophageal carcinoma cells in mature T cell-defective condition

We examined whether antitumor effect could be produced by retrovirally expressed human interleukin-2 (hIL-2) gene in human esophageal cancer cells (T.Tn) using immunocompromised nude mice. Loss of tumorigenicity of hIL-2-producing T.Tn (T.Tn/hIL-2) cells inoculated subcutaneously was observed in contrast to continuous tumor growth of wild-type cells, although in vitro proliferation of T.Tn/hIL-2 cells remained the same as that of wild-type cells. The antitumor effect was also evidenced by the injection of T.Tn/hIL-2 cells into established tumors of wild-type cells. The injection significantly retarded the subsequent growth of wild-type tumors. Histological examination of regressing T.Tn/hIL-2 cells revealed necrotic areas and infiltration of several types of inflammatory cells. Treatment of nude mice with anti-asialoGM1 antibody did not influence the IL-2-mediated tumor rejection. Vaccination of nude mice with irradiated T.Tn/hIL-2 cells whose secretion of hIL-2 in amount was comparable to that of unirradiated cells did not develop protective immunity. Taken together, the antitumor effect achieved in nude mice by the inoculation of T.Tn/hIL-2 cells is mediated by non-T non-natural killer cells.     

TL-10: A programming language for assembly robots

TL-10, Toyoto Robot Language-10, is a BASIC-like robot language. It has functions that define locations and subroutine parameters, which are useful in the accumulation and the transference of robot applied technology. It also has functions to communicate with other computers such as those for vision systems. The important features are described and illustrated by examples.     

Bending fatigue strength of case-carburized helical gears (In the case of large helix angles)

Case-carburizing enlarges the depth of the hardened layer at the tooth width end on the acute angle side of helical gears. For the helical gears with large helix angles (Exceeding 25°), this hardened layer may lower their bending fatigue strength. Therefore, we investigated the influence of this hardened layer on their bending fatigue strength through the bending fatigue tests. Our results suggest that this hardened layer might reduce the case-carburizing’s effect to enhance their bending fatigue strength. Thus, using only the maximum tooth root stress would be inadequate for evaluating their bending fatigue strength, and it would be necessary to consider the relationship between the hardened layer and the tooth root stress distribution (Especially, the stress applied at the tooth width end on the acute angle side) from the beginning of meshing to the end.     

Synthesis and properties of N-(α-carboxyalkyl)acrylamide telomer-type surfactants having multihydrocarbon chains

N-(α-Carboxyalkyl)acrylamide telomer-type surfactants (xC _n−1 AmAc where n is alkyl chain length=6, 8, 10, 12; and x is degree of polymerization=3.3–13.1) were synthesized by the telomerization of monomer (C _n−1 AmAc) in the presence of the corresponding alkanethiol as a chain transfer agent and then investigated for their surface-active properties. xC _n−1 AmAc telomers lowered the surface tension of aqueous solutions that were at pH 9–10. The critical micelle concentrations (CMC) of the telomers were lower than those of the monomers with the same alkyl chain length, and the CMC values shifted to lower concentrations with both increasing alkyl chain length and polymerization degree. xC₉AmAc with x=3.3–6.3 gave the highest efficiencies in lowering the surface tension. The cross-sectional molecular areas per molecule of xC _n−1 AmAc telomers were smaller than the values estimated on the assumption that they are assemblies of C _n−1 AmAc monomer units. The foaming abilities and the foam stabilities were both in the orders of xC₇AmAc>xC₉AmAc>xC₅AmAc>xC₁₁AmAc. Mixtures of aqueous solutions of xC _n−1 AmAc telomers and toluene formed oil-in-water emulsions. The emulsion-stabilizing abilities were in the orders of xC₇AmAc>xC₅AmAc>xC₉AmAc=xC₁₁AmAc. The addition of Ca²⁺ to the mixed solutions of telomers and toluene resulted in formation of water-in-oil type emulsions. Thus, the surface-active properties of the telomers were influenced significantly by the alkyl chain length and the polymerization degree of the telomers. In addition, these properties could be correlated with the hydrophilic-lipophilic balance (HLB); the highest surface activities were observed by using xC _n−1 AmAc with HLB of 14–18.     

Microstructure of AlN with two-domain structure on (001) diamond substrate grown by metal-organic vapor phase epitaxy

We investigate the microstructures of domain boundaries in an AlN layer grown on a (001) diamond substrate by metal-organic vapor phase epitaxy. The AlN layer has a two-domain structure with crystal orientation along either <112?0> AlN [named by AlN^I domain] or <101?0> AlN [named by AlN^II domain] parallel to [110] direction of diamond. The AlN^I and AlN^II domains are not atomically bonded at two-domain boundary from initial to final step of growth, while an edge-type dislocation is generated at single-domain boundary (SDB). In addition, an inversion AlN^I domain [named by AlN^I?] is randomly-ordered at the initial stage of the coalescence between the AlN^I domains. The AlN^I? is easily terminated with increasing the thickness of AlN^I domain. The inversion domain boundary changes to the edge-type dislocation at the SDB with further growth, which reduces the defect density in the AlN^I domains.     

Photocatalytic inactivation and removal of algae with TiO<Subscript>2</Subscript>-coated materials

The capabilities of TiO₂-coated materials for the inactivation and removal of algae were investigated. As supports for TiO₂, non-woven fabric and Ni foam were chosen. To evaluate the ability of noble metal cocatalyst additions to facilitate the photocatalytic algal inhibition of TiO₂-coated materials, Pd nanoparticles were deposited on non-woven fabric-supported TiO₂ by photoelectrochemical deposition. The fabric-supported Pd/TiO₂ showed higher inhibition activity for algal growth compared to the fabric-supported TiO₂ without Pd. In addition, Ni foam-supported TiO₂ also showed high inhibition activity, both in laboratory-scale tests and open-air tests. Therefore, TiO₂-coated materials with suitable coating methods such as the use of cocatalysts or large surface area can substantially inhibit algal growth. The ability of the TiO₂-coated materials to inhibit algae correlated well with their activity for the photocatalytic decolorization of methylene blue, suggesting a nonspecific mechanism in the breakdown of cellular structures.