Abstract: Pyrazine derivatives represented by general formula [1]: wherein the variables are as defined in the specification, or salts thereof have an excellent antiviral activity and are useful as a therapeutic agent for treating viral infections. Further, fluoropyrazine-carboxamide derivatives represented by general formula [2]: wherein the variables are as defined in the specification, or salts thereof are useful as an intermediate for production of the compounds of general formula [1], and as an intermediate for production of the fluoropyrazine-carboxamide derivatives of which one typical example is 6-fluoro-3-hyroxy-2-pyrazine-carboxamide having an antiviral activity.

Abstract: Nitrogen-containing heterocyclic carboxamide derivatives represented by the following general formula: wherein ring A is a substituted or unsubstituted pyrazine, pyrimidine, pyridazine or triazine ring; R1 is O or OH; R2 is a hydrogen atom, an acyl group or a substituted or unsubstituted carbamoylalkyl or carboxyalkyl group; and the broken line represents a single bond or a double bond; or salts thereof are useful for preventing and treating virus infections and especially influenza virus infections.

Abstract: Pyrazine derivatives represented by general formula [1]: 1

Abstract: A transfer control method includes a selecting step which selects one of a first route for making an asynchronous transfer to a request destination via a control block and a second route for making a synchronous transfer to the request destination by not passing the control block, with respect to a request from a request source.

Abstract: Nitrogen-containing heterocyclic carboxamide derivatives represented by the following general formula: 1

Abstract: The present invention relates to a 2,3-diketopiperazine derivative or a salt thereof, which has inhibitory effect on platelet aggregation because of glycoprotein IIb/IIIa receptor antagonism and hence is useful as a prophylactic and therapeutic agent for diseases associated with platelet aggregation.General formula ##STR1## wherein R.sup.1 represents a protected or unprotected amidino group; R.sup.2 represents a hydrogen atom or a carboxyl-protecting group; A represents a substituted or unsubstituted lower alkylene group; B represents --O--, --CONH--, --NHCO-- or --SO.sub.2 NH--; Y represents a substituted or unsubstituted lower alkylene group; and the broken line represents a single bond or a double bond.

Abstract: The present invention relates to a 2,3-diketopiperazine derivative or a salt thereof, which has inhibitory effect on platelet aggregation because of glycoprotein IIb/IIIa receptor antagonism and hence is useful as a prophylactic and therapeutic agent for diseases associated with platelet aggregation. General formula: ##STR1## wherein R.sup.1 represents a protected or unprotected amidino group; R.sup.2 represents a hydrogen atom or a carboxyl-protecting group; A represents a substituted or unsubstituted lower alkylene group; B represents --O--, --CONH--, --NHCO--or --SO.sub.2 NH--; Y represents a substituted or unsubstituted lower alkylene group; and the broken line represents a single bond or a double bond.

Abstract: An I/O interface control method and data processing equipment each of which can avoid data destruction in an I/O unit even when a channel control unit is in a check/stop state. When an abnormal state notification signal from the channel control unit has been received, the channel element completes an I/O operation in execution to halt a transmission to a new I/O operation. When the abnormal state notification signal delayed by a predetermined time has been received, the main storage control unit separates the channel control unit from the channel element to halt the data transmission. The present invention can be applicable to computer systems each including a DASD acting as an I/O unit.