Abstract: An object of the present invention is to provide a medicament as a thyroid hormone receptor ligand which is sufficient in drug efficacy and safety, and has the excellent action as a drug. The present invention provides a compound represented by the following general formula (I) or a pharmaceutically acceptable salt thereof: [wherein [Chemical Formula 2] is a single bond or a double bond; A is —CH2— or —CO—; X, Y, and Z are each independently a nitrogen atom or a carbon atom; R1 is a hydrogen atom or an aralkyl group; R2 is an alkyl group or an aralkyl group, etc.; R3 is a hydrogen atom or an alkyl group, etc.; R4 is a hydrogen atom or an alkyl group; R5 is a hydrogen atom, an alkyl group or a halo lower alkyl group, etc.; R6 is a hydrogen atom or an alkyl group; R7 is a hydrogen atom, etc.; R8 is a hydrogen atom, or an alkyl group, etc.; and E is —NHCO-G-COR12, etc. (wherein G is a single bond or an alkylene group, and R12 is a hydroxy group or an alkoxy group)].

Abstract: A dipeptidyl peptidase IV inhibitor which is satisfactory in respect of activity, stability and safety and has an excellent action as a pharmaceutical agent. A compound represented by the following general formula or a pharmaceutically acceptable salt thereof: wherein R1 and R2 each represents hydrogen, an optionally substituted C1-6 alkyl group, or —COOR5 whereupon R5 represents hydrogen or an optionally substituted C1-6 alkyl group, or R1, R2, and a carbon atom together represent a 3- to 6-membered cycloalkyl group, R3 represents hydrogen or an optionally substituted C6-10 aryl group, R4represents a hydrogen or a cyano group, D represents —CONR6-, —CO— or —NR6CO—, R6 represents hydrogen or an optionally substituted C1-6 alkyl group, E represents —(CH2)m— whereupon m is 1 to 3, —CH2OCH2—, or —SCH2—, n is 0 to 3, and A represents an optionally substituted bicyclic heterocyclic group or bicyclic hydrocarbon group.

Abstract: An optical communication system is formed by connecting a base station to user stations. Each user station has a transmitting section for upstream communication. The base station has a light source which supplies transmission light used for upstream communication.

Abstract: A dipeptidyl peptidase IV inhibitor which is satisfactory in respect of activity, stability and safety and has an excellent action as a pharmaceutical agent. A compound represented by the following general formula or a pharmaceutically acceptable salt thereof: wherein R1 and R2 each represents hydrogen, an optionally substituted C1-6 alkyl group, or —COOR5 whereupon R5 represents hydrogen or an optionally substituted C1-6 alkyl group, or R1, R2, and a carbon atom together represent a 3- to 6-membered cycloalkyl group, R3 represents hydrogen or an optionally substituted C6-10 aryl group, R4 represents a hydrogen or a cyano group, D represents —CONR6—, —CO— or —NR6CO—, R6 represents hydrogen or an optionally substituted C1-6 alkyl group, E represents —(CH2)m— whereupon m is 1 to 3, —CH2OCH2—, or —SCH2—, n is 0 to 3, and A represents an optionally substituted bicyclic heterocyclic group or bicyclic hydrocarbon group.

Abstract: An optical communication system is formed by connecting a base station to user stations. Each user station has a transmitting section for upstream communication. The base station has a light source which supplies transmission light used for upstream communication.