Abstract: An optical information recording medium comprising a substrate and formed thereon an information recording layer comprising at least two organic dyes having different chemical structures and continuous playback ability of 10.sup.5 times or more at a playback laser power of 0.5 to 1.5 mW, is excellent in readout light stability (durability) and reflectance.

Abstract: There are disclosed a novel naphthalocyanine derivative represented by the general formula [I] or [II] shown below, a process for preparing said derivative, an optical information recording medium using said derivative, and a process for preparing thereof: ##STR1## wherein M is a metal, metal oxide, metal hydroxide and the like, R.sup.1 is an alkyl group of 1-22 carbon atoms, n is an integer of 1 to 4, and Y.sub.1 and Y.sub.2 aryloxy group and the like.

Abstract: 2,3-dicyanonaphthalene derivatives useful in the synthesis of naphthalocyanine derivatives are disclosed. The 2,3-dicyanonaphthalene derivatives have the formula: ##STR1## wherein each R.sup.1 may be the same or different and represents an alkyl group, substituted alkyl group, or aryl group; and n is an integer from 1 to 4.

Abstract: Novel naphthalocyanine derivatives are disclosed in the specification are useful for forming a recording layer in an optical recording medium. These derivatives are represented by the following formula (I): ##STR1## in which k, l, m and n, which may be the same or different, are zero or integers of 1 to 4, k+l+m+n being an integer of 1 or more; R.sup.1 's in a number of (k+l+m+n), which may be the same or different, are alkyl groups, substituted alkyl groups, or aryl groups; M is Si, Ge or Sn; and two Y's, which may be the same or different, are aryloxyl groups, alkoxyl groups, trialkylsiloxyl groups, triarylsiloxyl groups, trialkoxysiloxyl groups, triaryloxysiloxyl groups, trityloxyl groups, or acyloxyl groups. These derivatives are especially useful in the preparation of an optical recording medium.

Abstract: In an optical data storage medium comprising a resin, substrate, a primary coat formed thereon and a recording layer of a dye decomposable by a laser beam formed on the primary coat, said primary coat is a silicone resin layer whose surface had been subjected to a plasma treatment. The primary coat prevents the substrate from attack by solvent for forming the recording layer, and enables the recording layer to be uniform in thickness with good adhesion.

Abstract: This invention discloses a process for producing tissue plasminogen activator. The process comprises cultivating Escherichia coli, yeast, or mammalian cells into which the vector having the gene for human tissue plasminogen activator (tPA) has been introduced by the recombinant DNA technology. In the cultivation or purification process, a specific antiplasmin agent, which is one of the protease inhibitors, is added to the medium and/or the buffer solutions used for purification, so as to prevent the conversion of single-chain form tPA into double-chain form tPA by a protease which is present in the medium.

Abstract: Disclosed are a novel naphthalocyanine dye shown in the specification, a method for preparing the same, and an optical information recording medium employing the same.According to the present invention, there can be obtained a novel naphthalocyanine dye, a method for preparing the same, and an optical information recording medium employing the same, which has excellent characteristics in recording/reading out property and in reading stability.

Abstract: An agent for treatment and prevention of asthma comprising 2-[2-phenyl-2-(2-pyridyl)]ethyl-2-imidazoline or a salt thereof as an active ingredient is disclosed.

Abstract: There is provided a stable enzyme composition comprising glutathione peroxidase and at least one stabilizer compound selected from the group consisting of pentoses, hexoses, penthahydric sugar alcohols, hexahydric sugar alcohols and disaccharides.