Abstract: Compounds represented by the general formula (1):   (where R1 is SR6 or NR7R8, where R6 is typically an alkyl group having 1-6 carbon atoms, R7 is a hydrogen atom, an alkyl group having 1-6 carbon atoms or a nitro group, and R8 is a hydrogen atom or an alkyl group having 1-6 carbon atoms; R2 and R3 are each typically a hydrogen atom or an alkyl group having 1-6 carbon atoms; R4 is a hydrogen atom, an alkyl group having 1-6 carbon atoms or an amidino group of which the amine portion may be substituted by an alkyl or nitro group; R5 is a hydrogen atom or an alkyl group having 1-6 carbon atoms; Y1, Y2, Y3 and Y4 which may be the same or different are each typically a hydrogen atom, a halogen atom or an alkoxy group having 1-6 carbon atoms; n and m are each an integer of 0 or 1), or possible stereoisomers or optically active forms of the compounds or pharmaceutically acceptable salts thereof.

Abstract: Compounds represented by the general formula (1): [wherein R1 is typically an aminoalkyl group; R2 is typically a hydrogen atom, a lower alkyl group, R3 or SR4 (where R4 is typically a lower alkyl group); Ar is typically a 5-membered aromatic heterocyclic group] have an NOS inhibiting activity and are useful as therapeutics of cerebrovascular diseases and other pharmaceuticals.

Abstract: Compounds represented by the general formula (1): (where R1 and R2 are typically a hydrogen atom; R3 and R4 are typically a hydrogen atom or a lower alkyl group; R5 is typically a hydrogen atom; X1, X2, X3 and X4 are typically a hydrogen atom or a lower alkoxy group; A is typically an optionally substituted pyridine ring; m and n are each 0 or 1) have an NOS inhibiting activity and are useful as therapeutics of cerebrovascular diseases and other pharmaceuticals.

Abstract: A two-dimensional matrix of complex coupled (gain or loss coupled) semiconductor DFB lasers is disclosed. The matrix includes several parallel branches of series lasers, each series having a plurality of lasers which are grown on the same wafer. The parallel branches are combined at either one end or both ends with either an integrated on-chip optical combiner or an external coupler to obtain a single optical output port. Each laser in the series comprises a multiple quantum well active region and a complex coupled grating having corrugations along a cavity length direction formed by periodic etching grooves through either the active region or the lossy QW region. The depth of etching is defined so as to provide a substantial insensitivity of each laser to the external feedback and random facet variations and to thereby ensure no substantial interaction between lasers in the series.

Abstract: Compounds represented by the general formula (I): ##STR1## (where R.sub.1 denotes a hydrogen atom, a straight-chained or branched alkoxycarbonyl group having 1-6 carbon atoms in which the alkyl portion may optionally have a substituent, or an optionally substituted straight-chained or branched acyl group having 1-9 carbon atoms;R.sub.2 denotes a hydrogen atom or an optionally substituted straight-chained or branched alkyl group having 1-6 carbon atoms;R.sub.3 denotes an optionally substituted straight-chained or branched alkyl group having 1-6 carbon atoms or an optionally substituted straight-chained or branched alkenyl group having 2-6 carbon atoms;R.sub.4 denotes a hydrogen atom;or alternatively R.sub.3 and R.sub.4 may combine together to form an optionally substituted 5- to 7-membered ring; andn denotes an integer of 2-4, provided that when R.sub.3 is a methyl group, n is not 3 at the same time) or pharmaceutically acceptable salts thereof.

Abstract: A one dimensional series of complex coupled (gain or loss coupled) DFB semiconductor lasers is disclosed. Each laser comprises a multiple quantum well active region and a complex coupled grating having corrugations along a cavity length direction formed by periodically etching grooves through the active region. The grating has a period comprising a first section and a second section, wherein substantially all quantum wells are etched away from the second section providing no substantial photon generation in the second section. The depth of etching is defined so as to provide a substantial insensitivity of each laser to the external feedback and random facet variations and to ensure no substantial interaction between lasers in the series. The lasers in the series may further comprise means for tuning laser wavelengths around corresponding lasing modes and/or means for switching between the lasing modes.

Abstract: The invention provides a complex coupled distributed feedback (DFB) semiconductor laser device with energy band gap modulation. The device comprises an active region formed on a substrate, and a barrier region adjacent the active region, the energy band gap of the barrier region modulated along a cavity length direction to form a complex coupled grating. The modal gain is higher in the barrier region areas, having narrower energy band gap, due to higher material gain and higher optical confinement factor in these areas. Periodic modulation of the energy band gap of the barrier region produces gain (or loss) modulation and index modulation in the material of the active region, thus, gain coupling and index coupling mechanisms being provided. Methods of producing gain modulation in the DFB laser, and fabrication thereof are also provided.

Abstract: Compound represented by the formula (I): ##STR1## or pharmaceutically acceptable salts thereof, as well as therapeutics for cerebrovascular diseases containing such compounds or salts as an active ingredient. The compounds are capable of selective inhibition of nitric oxide synthase in neurons and, hence, are useful as the active ingredient of therapeutics for cerebrovascular diseases.

Abstract: Antibacterial fluoroquinoline derivatives and salts thereof of the following formula are stable and have low toxicity and high photostability and low cytotoxicity under light irradiation: ##STR1## wherein R.sub.1 is hydrogen or lower alkyl;R.sub.2 is hydrogen, optionally protected amino, optionally protected aminocarbonyl or optionally protected carboxyl;R.sub.5 is halogen, lower alkyl or optionally protected hydroxyl or is the same as R.sub.2 ;R.sub.6 is lower alkyl;A is CH.sub.2, optionally protected nitrogen or oxygen;andn and m are each an integer of from 0 to 4, provided that n +m is an integer of from 1 to 4.

Abstract: A liquid crystal display converter has at least two frame memories. An alternative switching operation is performed by controlling the operations of an address generating circuit and a data switching circuit on the basis of an output from a frame counter. In the alternative switching operation, when one of the frame memories performs a writing operation, the other frame memory performs a reading operation. In contrast to this, when one of the frame memories performs a reading operation in the alternative switching operation, the other frame memory performs a writing operation. In this construction, the number of access operations of the frame memories is reduced so that the liquid crystal display converter can be constructed by a memory relatively cheaply manufactured without using any high speed memory. Accordingly, price of the liquid crystal display converter can be reduced.

Abstract: Electronic equipment includes a container unit for storing a battery or an AC adaptor which are detachable from the container unit and exchangeable with each other, an input port unit for receiving electric power from an external source, and a connection attachment unit for storing the battery and the AC adaptor which are detachable from the connection attachment unit, so that the AC adaptor can be stored in the connection attachment unit to supply DC power to the electronic equipment through the input port in order to charge the battery stored in the container unit, so that another battery can be stored in the connection attachment unit to supply DC power to the electronic equipment through the input port in order to serve as an expansion battery in addition to the battery stored in the container unit, or so that both the battery and the AC adaptor can be stored in the connection attachment unit to charge the battery.

Abstract: A multi-wavelength laser array having a plurality of gain-coupled distributed feedback ridge waveguide lasers. The operational wavelength of each laser is established by selecting a width of the ridge waveguide in the range 1.6 .mu.m to 5.2 .mu.m. Fine tuning of each central wavelength is achieved by thermal power to selected waveguides via Titanium thin film resistors integrated into the laser array. A wavelength range of 9 nm is demonstrated utilizing a sixteen element array.

Abstract: A Type II heterojunction formed of semiconductor material which normally forms a Type I heterojunction. The Type II heterojunction is created by using a carefully chosen stack of epitaxial semiconductor materials with modifications to the band structure through quantum mechanical confinement effects. This virtual type II heterojunction is incorporated adjacent to the active region in a single-quantum-well, ridge-waveguide laser structure. An anomalous "Negative-T.sub.o " region is observed in which threshold current decreases with increasing temperature. A reduction in the temperature sensitivity of the threshold current of the laser structure results.

Abstract: A surface emitting, circular grating, semiconductor laser. Gain is generated by injecting current into an active, annular mesa region which surrounds a central, circular region having a circular grating for surface emission. The annular mesa region is surrounded by an outer annular region in which is etched a first order grating for creating feedback. Methods of fabricating the circular grating laser are also described.

Abstract: A head positioning system for use with a magnetic disk with outer, middle and inner servo tracks which are radially separated by data tracks. The head positioning system includes a measuring element for measuring deviations of the magnetic head from the outer, middle and inner servo tracks by reading the servo information recorded on each of the servo tracks and generating first, second and third deviation values. The head positioning system also includes a determining element which determines an offset correction value for a targtet data track included in the data tracks in accordance with a quadratic compensation function and the first, second and third deviation values. A fine positioning element positions the magnetic track of the target track according to the offset correction value.

Abstract: In a magnetic head assembly wherein each magnetic head is moved along a magnetic recording medium by an arm element coupled to a shaft which has an axis held in a substantially perpendicular relation to a reference plane, an angle adjusting arrangement is coupled to the shaft to adjust an angle between the axis and the reference plane within the substantially perpendicular relation. Preferably, the shaft has a fixed end and a free end adjustable to make the angle between the axis and the reference plane. The angle adjusting arrangement may comprise a pair of electromechanical transducing elements, such as piezoelectric elements, coupled to the free end for use in adjusting the angle. The angle adjusting arrangement may further comprise a leaf spring element between the electromagnetic elements for urging the free end towards a position which the free end has before adjustment of the angle.

Abstract: Room heating apparatus having a burner disposed in the upper part of a body to which air for combustion is forcibly supplied from a blower, a heat exchanger and a combustion chamber serially connected below the burner, and a second blower for recycling air from the room over the outer surfaces of the heat exchanger and the combustion chamber being disposed in the bottom of the body. The combustion chamber and the heat exchanger are substantially flat-shaped in configuration being on the order of ten times their thickness in both height and width.Accordingly, the room heating apparatus is a compact heating unit having high thermal efficiency, and the blower for recycling air can be protected from damage due to heat of the burner, even in the event the blower is accidentally stopped.