Abstract: The novel indole derivatives and salts thereof represented by the general formula (1) ##STR1## possess, for example, an inhibitory effect against superoxide (O.sub.2.sup.-) released from the macrophage cells of guinea pig by stimulation and an anti-albuminuria activity against Masugi nephritis, and are useful in various clinical fields as an agent for preventing and treating diseases and cases associated with the above superoxide radical, for example, autoimmune diseases (e.g. rheumatism), arteriosclerosis, ischemic disease, ischemic encephalopathia, hepatic insufficiency and renal insufficiency, and also as an agent for preventing and treating nephritis.

Abstract: A diamond composite combined with a cobalt-containing substrate, comprising: a sintered mass of diamond, in which practically all the diamond particles are joined immediately with adjacent particles, a mass of cobalt-containing carbide, said latter mass being larger than the former and said first and latter masses being of a same cross section at the opposed ends, and an intermediate layer of a solid material which consists of Mo, Co and C with a minor proportion of inevitable impurities and which comprises a molybdenum carbide exhibiting a melting point within 200 degrees C. of that of the first said carbide material, said layer intervening between the masses and having a total radial cross sectional area of at least 80% but not greater than 97% of that of the diamond mass and carbide masses at the joint and a thickness of, at least, 25 microns over the whole cross sectional area and method for producing the same.