Abstract: A method for producing a pyrimidine nucleoside compound includes reacting a sugar phosphate and pyrimidine base derivative using an enzyme having cytosine nucleoside phosphorylase activity, the pyrimidine base derivative being represented by general formula (I): (wherein R1 represents an amino group that may be replaced with an acyl group having an alkyl group of 1 to 3 carbon atoms or an alkyl group of 1 to 3 carbon atoms, an alkyl group of 1 to 3 carbon atoms, or a thiol group; R2 represents an amino group, a thiol group, a hydroxyl group, or a hydrogen atom; R3 represents an alkyl group of 1 to 3 carbon atoms that may be replaced with a hydroxyl group, an amino group, or a hydrogen atom; R4 represents a hydroxyl group or a hydrogen atom; when R1 is an amino group, when R2 is a hydroxyl group, and when R4 is a hydrogen atom; R3 is neither an alkyl group of 1 to 3 carbon atoms nor a hydrogen atom).

Abstract: This invention provides a novel D-aminoacylase obtained by cloning a DNA encoding the novel D-aminoacylase from Methylobacterium mesophilicum MT 10894, etc. and which shows sufficiently high activity at an industrially useful substrate concentration to allow a D-amino acid to be efficiently produced from an N-acyl-DL-amino acid; a DNA encoding the D-aminoacylase; a process for producing a D-amino acid from the corresponding N-acylamino acid using a transformant containing the DNA.

Abstract: A novel gluconate dehydratase derived from Achromobacter xylosoxidans and a gene encoding the gluconate dehydratase are provided. By reacting the gluconate dehydratase or a transformed cell containing the gene with an aldonic acid, the corresponding 2-keto-3-deoxyaldonic acid can be efficiently produced.

Abstract: The invention provides a method for producing a cytosine nucleoside compound from pentose-1-phosphate and cytosine or a derivative thereof using a nucleoside phosphorylase reactive to cytosine or a bacterium having the enzyme activity. The invention also provides a method for specifically reducing an activity to degrade the substrates or the product, resulting in efficient production of the cytosine nucleoside compound. According to the invention, little by-product is produced in producing cytonucleocide compounds.

Abstract: This invention provides a novel D-aminoacylase obtained by cloning a DNA encoding the novel D-aminoacylase from Methylobacterium mesophilicum MT 10894, etc. and which shows sufficiently high activity at an industrially useful substrate concentration to allow a D-amino acid to be efficiently produced from an N-acyl-DL-amino acid; a DNA encoding the D-aminoacylase; a process for producing a D-amino acid from the corresponding N-acylamino acid using a transformant containing the DNA.

Abstract: The invention provides a method for producing a cytosine nucleoside compound from pentose-1-phosphate and cytosine or a derivative thereof using a nucleoside phosphorylase reactive to cytosine or a bacterium having the enzyme activity. The invention also provides a method for specifically reducing an activity to degrade the substrates or the product, resulting in efficient production of the cytosine nucleoside compound. According to the invention, little by-product is produced in producing cytonucleocide compounds.

Abstract: Light distribution characteristics are defined which define a correspondence relation between the position of a reflection point on a reference plane and the position of an image of a light source. In accordance with the light distribution characteristics, a path line in the reference plane is determined. A profile curve for each of a plurality of sampling points dispersibly distributed on the path line, is determined in accordance with the light distribution characteristics, the profile curve passing through the sampling point and corresponding to the topological shape of a reflecting surface to be determined. As the reflection point moves along the profile curve, the image of the light source moves in the direction crossing the reference plane in accordance with the light distribution characteristics. The topological shape of the reflecting surface is determined in accordance with the profile curve determined for each sampling point.

Abstract: A valve operating system in an internal combustion engine includes a cam shaft provided with a valve operating cam, a rocker arm having a pair of support wall portions which are integrally connected at their base ends to a swinging support portion swingably supported on a support member mounted on a cylinder head and which are opposed to each other at a distance in a direction along the swinging axis of the swinging support portion, a support shaft supported between the support wall portions, and a roller which is rotatably supported on the support shaft with a bearing interposed therebetween so as to be in rolling contact with the valve operating cam. A lower connecting wall interconnecting lower portions of the base ends of the support wall portions is projectingly provided on the swinging support portion in a manner opposed to an outer peripheral surface of a lower portion of the roller. Thus, it is possible to increase the rigidity of the rocker arm, while avoiding an increase in size of the rocker arm.

Abstract: Optically active chroman-3-acetic acids and optically active chroman-3-acetic acid esters can be obtained by treating a mixture of (3R)- and (3S)-chroman-3-acetic esters of formula (I) [wherein R1 is a straight or branched alkyl group having 1-5 carbon atoms and R2 is a hydrogen atom or substituted or unsubstituted amino group] is treated with an esterase which has an optically selective hydrolyzing activity or microorganisms which carry said hydrolase, or a preparation therefrom. A novel esterase derived from bacteria of genus Pseudonocardia can also be used as said esterase.

Abstract: A valve operating system in an internal combustion engine includes a cam shaft provided with a plurality of valve operating cams, a plurality of rocker arms positioned adjacent one another, an associative operation switch capable of being switched between a state in which it permits the rocker arms adjacent each other to be operated associatively with each other, and a state in which it releases the associative operation. An urging means for urging the free rocker arm of the plurality of rocker arms toward the valve operating cam corresponding to the free rocker arm, which becomes free relative to an engine valve, when the associative operation switch is brought into the associative operation releasing state.

Abstract: Optically active chroman-3-acetic acids and optically active chroman-3-acetic acid esters can be obtained by treating a mixture of (3R)- and (3S)-chroman-3-acetic esters of formula (I) ##STR1## [wherein R.sub.1 is a straight or branched alkyl group having 1-5 carbon atoms and R.sub.2 is a hydrogen atom or substituted or unsubstituted amino group]is treated with an esterase which has an optically selective hydrolyzing activity or microorganisms which carry said hydrolase, or a preparation therefrom. A novel esterase derived from bacteria of genus Pseudonocardia can also be used as said esterase.

Abstract: A valve operating system in an internal combustion engine includes a cam shaft provided with a plurality of valve operating cams, a plurality of rocker arms positioned adjacent one another, an associative operation switch capable of being switched between a state in which it permits the rocker arms adjacent each other to be operated associatively with each other, and a state in which it releases the associative operation. An urging means for urging the free rocker arm of the plurality of rocker arms toward the valve operating cam corresponding to the free rocker arm, which becomes free relative to an engine valve, when the associative operation switch is brought into the associative operation releasing state.

Abstract: A valve-operation control system for an internal combustion engine includes a timing transmitting device for transmitting the rotational power of a crankshaft at a speed reduction ratio of 1/4 to a cam shaft, and intake-side and exhaust-side valve operating devices.

Abstract: A valve operating device for use in an internal combustion engine for varying operating characteristics of a pair of engine valves (20) in multi-stages depending upon operating conditions of the engine. A cam shaft (31) is provided with a high-speed cam (32), a pair of medium-speed cams disposed on opposite sides of the high-speed cam (32), and a pair of low-speed cams (34) disposed between the medium-speed cams (33) and the high-speed cam (32). A rocker shaft (35) is provided with a first free rocker arm (36) in sliding contact with the high-speed cam (32), a pair of driving rocker arms (37) operatively connected to the pair of engine valves (20), respectively, and in sliding contact with the low-speed cams (34), and a pair of second free rocker arms (38) disposed with the driving rocker arms (37) interposed between the second free rocker arms (38) and the first free rocker arm (36) to be in sliding contact with the medium-speed cams (33).

Abstract: Disclosed is a cloned tyrosine phenol-lyase gene which encodes an amino acid sequence represented by the formula [I], which can be expressed in the absence of tyrosine in culturing medium. A recombinant vector containing the tyrosine phenol-lyase gene as well as E. coli transformants capable of producing tyrosine phenol-lyase are also disclosed.

Abstract: In a dual-fuel internal combustion engine which can selectively use gaseous fuel such as CNG or liquid fuel such as gasoline, a pair of intake passages are independently connected to a combustion chamber of the engine, and a gaseous fuel supply device and a liquid fuel supply device are provided in the corresponding intake passages so that the liquid and gaseous fuels may not mix with each other when the fuel for the engine is switched over one from the other as they are introduced into the combustion chamber through different intake passages. Further, by switching the operating mode of the intake valve when changing the fuel, the configuration of the intake passage can be optimized for each fuel, and the timing and the lift of the intake valves may also be optimized for each fuel without complicating the control structure of the overall system. The present invention can improve the torque output and the emission property of the dual-fuel engine.

Abstract: An intake system of a multi-cylinder interval combustion engine including a common inlet duct, first and second resonating ducts branched from the downstream end of the inlet duct, first and second resonating chambers leading from the first and second resonating ducts, respectively, a plurality of first intake ducts for connecting the first resonating chamber to a first group of cylinders, respectively, having ignition timings set not to come adjacent to each other, respectively, a plurality of second intake ducts for connecting the second resonating chamber to a second group of cylinders, respectively, having ignition timings set not to come adjacent to each other, a common intake chamber capable of communicating with both the resonating chambers through communication ports which can be closed by valves, and an actuator for opening and closing the valves at least in response to the engine revolutions.

Abstract: A method for casting a rocker arm made of light alloy for use in an overhead cam shaft type valve operating mechanism of an internal combustion engine, which rocker arm includes a thick-walled bearing section to be fitted on a rocker arm shaft and is integrally provided with a wear-resistive piece having a protrusion on its rear surface and adapted to abut a cam. After molten metal has been injected under pressure into a metallic mold for the rocker arm, a secondary pressurizing force directed in the direction of an imaginary center axis of a rocker arm shaft is exerted by means of a pressurizing rod. In the metallic mold for the rocker arm, a sprue is provided close to the position where the wear-resistive piece is disposed with respect to the position where the bearing section is formed, and the direction of the sprue is directed towards the position where the wear-resistive place is disposed.

Abstract: A lubricant supplying system for a DOHC type multicylinder internal combustion engine comprising a plurality of cylinders arranged in series in a cylinder block, a pair of cam shafts parallel to each other and rotatably supported by a cylinder head and cam holders fixed to the cylinder head at opposite sides of the respective cylinders along the cylinder arranging direction, a plurality of cams including low speed cams corresponding to intake and exhaust valves of the respective cylinders and fixed to the cam shafts, a plurality of rocker arms in slidable contact with the respective cams corresponding to the intake and exhaust valves of the respective cylinders, and a connection switching mechanism for switching connection and disconnection of the rocker arms in response to a hydraulic pressure to vary the operating states of the valves responsive to the operating state of the engine, wherein a hydraulic pressure supply passage independent from an oil supply passage for supplying a hydraulic pressure to the c