Abstract: Components that demonstrate an ?-glucosidase inhibitory activity and hyperglycemic inhibitory activity have clearly been provided from among the components included in Yacon. The present inventors found that as a result of screening for a strong anti-oxidant component in a Yacon aerial portion extract, an antioxidant activity was converged in a DIAION HP-20 column chromatography 50% methanol-eluted fraction of hot water extract. Thus, since a previously unidentified high-content component was confirmed, the present inventors conducted purification thereof, and thereby separated TCAA. As a result, this TCAA was found to be the component that demonstrates the ?-glucosidase inhibitory activity and hyperglycemic inhibitory activity.

Abstract: Components that demonstrate an ?-glucosidase inhibitory activity and hyperglycemic inhibitory activity have clearly been provided from among the components included in Yacon. The present inventors found that as a result of screening for a strong anti-oxidant component in a Yacon aerial portion extract, an antioxidant activity was converged in a DIAION HP-20 column chromatography 50% methanol-eluted fraction of hot water extract. Thus, since a previously unidentified high-content component was confirmed, the present inventors conducted purification thereof, and thereby separated TCAA. As a result, this TCAA was found to be the component that demonstrates the ?-glucosidase inhibitory activity and hyperglycemic inhibitory activity.

Abstract: A silicon carbide layer between a silicon substrate or layer and a metal layer because silicon carbide has many properties similar to those of silicon, has a very slow diffusion rate of a metal through the silicon carbide, or prevents a diffusion of a metal into the silicon, and can be deposited by CVD, which has an advantage of a good coverage over a step portion such as a contact window.

Abstract: A single crystalline silicon carbide (.beta.-SiC) layer having a thickness greater than 1 .mu.m is grown on a silicon substrate by the following method of the present invention. The silicon substrate is provided in a reactor chamber, and the reactor chamber is evacuated and maintained at a reduced atmospheric pressure during the growing processes. While flowing a mixed gas containing acetylene into the reactor chamber, the substrate is heated up at a temperature range from 800.degree. to 1000.degree. C., preferable in a range from 810.degree. to 850.degree. C., whereby a buffer layer of carbonized silicon having a thickness of 60 to 100 .ANG. is grown on the substrate. Thereafter, the flowing gas is changed to a mixed gas containing hydrocarbon and chlorosilane, and the substrate temperature is raised to a temperature from 850.degree. to 950.degree. C. In this process, a single crystalline .beta.-SiC layer can be grown on the buffer layer, and a thickness of a few .mu.m for the grown .beta.

Abstract: In a process for producing at least one Nb.sub.3 Sn superconductor which comprises drawing a composite composed of a core of niobium or a niobium alloy and a matrix of a copper-tin alloy and subjecting the drawn composite to reactive heat-treatment, thereby forming a layer of Nb.sub.3 Sn between the core and the matrix; the improvement wherein the copper-tin alloy contains 1 to 15 atomic percent of tin, and 0.1 to 8 atomic percent in total of at least one element selected from 0.1 to 8 atomic percent of titanium, 0.1 to 5 atomic percent of zirconium and 0.1 to 5 atomic percent of hafnium.

Abstract: A superconductor including V.sub.3 Ga is produced by making a composite of a vanadium core metal, a continuous portion of aluminum surrounding the vandium core metal or forming a second core, and a copper, silver or copper-silver alloy containing gallium, fabricating the composite to the desired shape, and heat-treating the shaped composite. The vanadium core may contain titanium, zirconium or hafnium, and the continuous portion of aluminum may contain copper or zirconium.

Abstract: A superconductor including V.sub.3 Ga is produced by making a composite of a vanadium core metal, a continuous portion of aluminum surrounding the vanadium core metal or forming a second core, and a copper, silver or copper-silver alloy containing gallium, fabricating the composite to the desired shape, and heat-treating the shaped composite. The vanadium core may contain titanium, zirconium or hafnium, and the continuous portion of aluminum may contain copper or zirconium.