Abstract: Provided is a process for producing an isocoumarin-3-yl-acetic acid derivative, characterized by reacting a homophthalic acid derivative represented by a formula: 1

Abstract: Provided is a process for producing an isocoumarin-3-yl-acetic acid derivative, characterized by reacting a homophthalic acid derivative represented by a formula: (wherein Rc, R2 and R are mainly protecting groups) with a malonic acid derivating represented by a formula: (wherein R is an organic group including a lower alkyl group; R3 is a protecting group for a carboxyl group; and X is a halogen atom or a —OM group (wherein M is alkaline metal or alkaline earth metal)). According to the above process, various isocoumarin-3-yl-acetic acid derivatives can efficiently be provided.

Abstract: This invention provides DNA fragments for efficiently preparing a protein having asymmetric hydrolase activity for 4-substituted 1,4-dihydropyridine derivatives, transformants obtained by using such a DNA fragment, and a process for preparing the aforesaid enzyme. Specifically, an isolated gene derived from the chromosome of Streptomyces viridosporus and encoding a protein having asymmetric hydrolase activity for 4-substituted 1,4-dihydropyridine derivatives, plasmids having the aforesaid gene integrated thereinto, transformants obtained by using such a plasmid, and a process for preparing the aforesaid enzyme by using such a transformant are disclosed. A process for the enzymatic conversion of 4-substituted 1,4-dihydropyridine derivatives by using the aforesaid enzyme is also disclosed.

Abstract: When a second disc is inserted, recording and/or reproducing operation of information on or from a first disc is stopped, and a moving member is moved in the X1-direction. This movement allows a clamp chassis to be moved upward and unclamped, and the second disc is carried into a disc apparatus by a transfer roller and is supported by disc guides. Then, the first and the second discs are supported by the disc guides and are moved upward and then, the first disc is carried out of an insertion opening by the transfer roller. In the course of the movement of the drive chassis to the upper position, the second disc is placed on a turntable, and is chucked and clamped by a clamper. Therefore, it is possible to exchange the second disc with the first disc only by inserting the second disc.

Abstract: There is provided a disk device capable of shortening a replacing time for a disk.

Abstract: There is provided a disk device wherein an insertion/ejection slot for a disk, and two upper and lower disk D transferring paths connected to the insertion/ejection slot are provided; between the upper transferring path and the lower transferring path, a transferring roller for transferring the disk is disposed; an upper roller portion and a lower roller portion of the transferring roller are disposed so as to face the upper and lower transferring paths, respectively; in the upper roller portion and the lower roller portion, there are provided pressing members, having pressing surfaces to be arranged so as to oppose to each other; and the disk is caught between the pressing surface and the upper roller portion, or between the pressing surface and the lower roller portion to rotate the transferring roller thereby transferring the disk.

Abstract: Conventional disc units each involve the problem that a new disc must be inserted into the disc unit after a disc already present in the disc unit is ejected and that therefore it takes time for disc replacement. In the disc unit of the present invention, to solve the above-mentioned problem, a new second disc which has been inserted into the disc unit through an insertion opening is carried from an insertion area to a disc driving section by a conveying means. On the other hand, a first disc already present in the disc unit prior to insertion of the second disc is ejected from an ejection area to the exterior of the disc unit by both first and second ejection members. The time required for disc replacement can be shortened by performing the disc inserting operation by the conveying means and the disc ejecting operation by the first and second ejection members both in a simultaneous manner.

Abstract: This invention provides DNA fragments for efficiently preparing a protein having asymmetric hydrolase activity for 4-substituted 1,4-dihydropyridine derivatives, transformants obtained by using such a DNA fragment, and a process for preparing the aforesaid enzyme. Specifically, an isolated gene derived from the chromosome of Streptomyces viridosporus and encoding a protein having asymmetric hydrolase activity for 4-substituted 1,4-dihydropyridine derivatives, plasmids having the aforesaid gene integrated thereinto, transformants obtained by using such a plasmid, and a process for preparing the aforesaid enzyme by using such a transformant are disclosed. A process for the enzymatic conversion of 4-substituted 1,4-dihydropyridine derivatives by using the aforesaid enzyme is also disclosed.

Abstract: Optically active 1,4-dihydropyridine derivatives represented by general formula (I) and anion salts thereof and a production method therefor: ##STR1## (wherein R.sup.1 represents a C.sub.1-6 alkyl group, R.sup.2 represents a nitrogen-containing heterocyclic group forming a quaternary ammonium which may be substituted, and n is an integer of 1, 2 or 3). The optically active 1,4-dihydropyridine derivatives represented by general formula (I) have vasodilating activity and hypotensive activity and are excellent in water solubility so that they are useful as a drug for circulatory system such as a hypotensor or vasodilator.

Abstract: Disclosed are the novel C-glycoside compounds Mer-1020dA, Mer-1020dB, Mer-1020dC and Mer-1020dD which have a chromophore group in common with well-known chrysomycins A and B, but can be distinguished from the chrysomycins and the like in that the novel C-glycoside compounds have a sugar residue having a higher degree of oxidation, as well as the compound Mer-1020dE comprising only the chromophore thereof. Among these compounds, the C-glycoside compounds are antibiotics which have low toxicity and can strongly inhibit the growth of solid cancer cells in particular.

Abstract: An improved bipolar transistor of BiCMOS is provided to improve the breakdown voltage between a collector and a base. A low concentration diffusion layer is provided at a main surface of a semiconductor substrate at a boundary between an outer perimeter of an external base layer and an end portion of a field oxide film. The low concentration diffusion layer expands from the main surface of the semiconductor substrate toward the inside of the substrate and has a concentration lower than the impurity concentration of the external base layer.

Abstract: A rectifying transfer gate circuit includes first and second field effect transistors and one diode. The source of the first field effect transistor is coupled to a first input node and the gate thereof is coupled to a second input node. Meanwhile, the source of the second field effect transistor is coupled to the second input node and the gate thereof is coupled to the first input node. The diode is coupled between the common drain of the first and second field effect transistors and an output node, so as to increase the speed of the operation in the application circuit utilizing the above rectifying transfer gate circuit.

Abstract: A rectifying transfer gate circuit includes first and second field effect transistors and one diode. The source of the first field effect transistor is coupled to a first input node and the gate thereof is coupled to a second input node. Meanwhile, the source of the second field effect transistor is coupled to the second input node and the gate thereof is coupled to the first input node. The diode is coupled between the common drain of the first and second field effect transistors and an output node, so as to increase the speed of the operation in the application circuit utilizing the above rectifying transfer gate circuit.

Abstract: An bipolar transistor of BiCMOS is provided to improve the breakdown voltage between a collector and a base. A low concentration diffusion layer is provided at a main surface of a semiconductor substrate at a boundary between an outer perimeter of an external base layer and an end portion of a field oxide film. The low concentration diffusion layer expands from the main surface of the semiconductor substrate toward the inside of the substrate and has a concentration lower than the impurity concentration of the external base layer.

Abstract: Disclosed are 1,4-dihydropyridine derivatives represented by the general formula (I) and salts thereof, as well as optical active 1,4-dihydropyridine derivatives represented by the general formula (II) and salts thereof which are obtained from the derivative by biochemical reactions using microorganisms or enzymes and useful as preventive and therapeutic agents for ischemic heart diseases and hypertension. ##STR1## (wherein x and Y are H, NO.sub.2, CN, halogen; R.sup.1 and R.sup.2 are H, CHO, substituted alkylcarbonyl, crotonyl, cinnamoyl, alkoxycarbonyl, aryloxycarbonyl, benzyloxycarbonyl, carboxybenzoyl, or R.sup.1 and R.sup.2 taken together represent phthaloyl; n is an integer of 1 to 3).

Abstract: A semiconductor device which remains highly reliable and is easy to mount even when a bonding pad pitch is reduced. The semiconductor device is featured in that a thermally conductive support substrate in which a semiconductor chip is fixed to a recessed portion is mounted on the reverse side of an insulating tape, that is, a TAB substrate having a conductor pattern on the surface; and solder balls are placed on the front side of the insulating tape to ensure connection to the conductor pattern on the front side through holes.

Abstract: A rectifying transfer gate device having two transistors with a common drain region of a first conductivity. A doped region of a second conductivity opposite the first conductivity is positioned between the common drain region and corresponding drain electrode. This configuration forms a PN junction that acts as a diode by inhibiting electrical conduction. Therefore malfunctions due to undesired circulating current are decreased.

Abstract: Method for producing semiconductor devices comprises a first step in which a plurality of metal substrates each of which is provided with a die mounting region at a central portion thereof are connected in series to produce a train of connected metal substrates by means of first connecting tabs and a pair of first side rails each of which is provided with first positioning pilot apertures are connected to the train by means of second connecting tabs to produce a metal substrate frame, a second step in which a plurality of circuit substrates each of which is provided with a lead pattern around an opening formed at the central portion thereof are connected in series by means of third connecting tabs to produce a train of connected circuit substrates and a pair of second side rails each of which is provided with second positioning pilot apertures are connected by fourth connecting tabs to produce a circuit substrate frame, a third step in which both frames are alinged with each other making use of the first and

Abstract: A semiconductor device comprises a circuit substrate being provided with a first lead pattern and a second lead pattern on a front surface and rear surface thereof respectively. The first lead pattern includes a die mounting region and conductive leads. The second lead pattern includes first outer connecting terminal lands connected with the die mounting region by way of first vias, second outer connecting terminal lands connected with the conductive leads of the first lead pattern by way of second vias, and a ground plane connected with the first outer connecting terminal lands while being electrically and magnetically shielded from the second outer connecting terminal lands. Solder balls are mounted on the first and second outer connecting terminal lands respectively. A semiconductor die is fixedly mounted on the die mounting region. Bonding wires connect electrode pads mounted on the semiconductor die with the conductive leads respectively.

Abstract: (4R)-3-(Substituted aminoalkyl)oxycarbonyl-1,4-dihydro-2,6-dimethyl-4-(nitrophenyl)pyridine-5- carboxylic acids can be prepared efficiently, by reacting bis(substituted aminoalkyl) 1,4-dihydro-2,6-dimethyl-4-(nitrophenyl)pyridine-3,5-dicarboxylates with a microorganism capable of asymmetric hydrolysis and belonging to the genus Streptomyces, the genus Paecilomyces, the genus Botryodioplodia, the genus Alternaria or the genus Helminthosporium, or a treated product thereof. The compounds are extremely useful as important intermediates for preparation of pharmaceuticals useful for the prevention and treatment of angina pectoris, hypertension, etc.