Abstract: A first aspect of the present invention is carbon fiber wherein the surface of a monofilament has a center line average roughness Ra of 6.0 nm or more and 13 nm or less, and the monofilament has a long diameter/short diameter ratio of 1.11 or more and 1.245 or less. A second aspect of the present invention is carbon fiber precursor acrylic fiber wherein the surface of a monofilament has a center line average roughness Ra of 18 nm or more and 27 nm or less, and the monofilament has a long diameter/short diameter ratio of 1.11 or more and 1.245 or less. The carbon fiber according to the first aspect is obtained by stabilizing and carbonizing under specific conditions the carbon fiber precursor acrylic fiber according to the second aspect.

Abstract: A photopolymerization initiator which is a compound having a structure in which one or more carbonyl groups that link to a carbon atom are further directly bonded to an aromatic ring of an aromatic acyl group that bonds to a phosphorus atom in an acylphosphine oxide structure. A producing method of a photopolymerization initiator produces the photopolymerization initiator. In a polymerizable composition and an ink jet recording method, the photopolymerization initiator is used. Furthermore, an acylphosphine oxide compound has a partial structure represented by Formula 1 or Formula 2.

Abstract: A photopolymerization initiator which is a compound having a structure in which one or more carbonyl groups that link to a carbon atom are further directly bonded to an aromatic ring of an aromatic acyl group that bonds to a phosphorus atom in an acylphosphine oxide structure. A producing method of a photopolymerization initiator produces the photopolymerization initiator. In a polymerizable composition and an ink jet recording method, the photopolymerization initiator is used. Furthermore, an acylphosphine oxide compound has a partial structure represented by Formula 1 or Formula 2.

Abstract: A photopolymerization initiator which is a compound having a structure in which one or more carbonyl groups that link to a carbon atom are further directly bonded to an aromatic ring of an aromatic acyl group that bonds to a phosphorus atom in an acylphosphine oxide structure. A producing method of a photopolymerization initiator produces the photopolymerization initiator. In a polymerizable composition and an ink jet recording method, the photopolymerization initiator is used. Furthermore, an acylphosphine oxide compound has a partial structure represented by Formula 1 or Formula 2.

Abstract: A compound represented by a formula [1D] as shown below (wherein R1A, R1B, R2A, R2B, R3A and R3B represent a hydrogen atom, an optionally substituted C1-6 alkyl group, and the like) is useful as an intermediate for producing a thionucleoside, and the production method of the present invention is useful as a method for producing a thionucleoside.

Abstract: A compound represented by a formula [1D] as shown below (wherein R1A, R1B, R2A, R2B, R3A and R3B represent a hydrogen atom, an optionally substituted C1-6 alkyl group, and the like) is useful as an intermediate for producing a thionucleoside, and the production method of the present invention is useful as a method for producing a thionucleoside.

Abstract: A compound represented by a formula [1D] as shown below (wherein R1A, R1B, R2A, R2B, R3A and R3B represent a hydrogen atom, an optionally substituted C1-6 alkyl group, and the like) is useful as an intermediate for producing a thionucleoside, and the production method of the present invention is useful as a method for producing a thionucleoside.

Abstract: A photopolymerization initiator which is a compound having a structure in which one or more carbonyl groups that link to a carbon atom are further directly bonded to an aromatic ring of an aromatic acyl group that bonds to a phosphorus atom in an acylphosphine oxide structure. A producing method of a photopolymerization initiator produces the photopolymerization initiator. In a polymerizable composition and an ink jet recording method, the photopolymerization initiator is used. Furthermore, an acylphosphine oxide compound has a partial structure represented by Formula 1 or Formula 2.

Abstract: A compound represented by a formula [1D] as shown below (wherein R1A, R1B, R2A, R2B, R3A and R3B represent a hydrogen atom, an optionally substituted C1-6 alkyl group, and the like) is useful as an intermediate for producing a thionucleoside, and the production method of the present invention is useful as a method for producing a thionucleoside.

Abstract: A compound represented by a formula [1D] as shown below (wherein R1A, R1B, R2A, R2B, R3A and R3B represent a hydrogen atom, an optionally substituted C1-6 alkyl group, and the like) is useful as an intermediate for producing a thionucleoside, and the production method of the present invention is useful as a method for producing a thionucleoside.

Abstract: A compound represented by a formula [1D] as shown below (wherein R1A, R1B, R2A, R2B, R3A and R3B represent a hydrogen atom, an optionally substituted C1-6 alkyl group, and the like) is useful as an intermediate for producing a thionucleoside, and the production method of the present invention is useful as a method for producing a thionucleoside.

Abstract: A compound represented by a formula [1D] as shown below (wherein R1A, R1B, R2A, R2B, R3A and R3B represent a hydrogen atom, an optionally substituted C1-6 alkyl group, and the like) is useful as an intermediate for producing a thionucleoside, and the production method of the present invention is useful as a method for producing a thionucleoside.

Abstract: A compound represented by a formula [1D] as shown below (wherein R1A, R1B, R2A, R2B, R3A and R3B represent a hydrogen atom, an optionally substituted C1-6 alkyl group, and the like) is useful as an intermediate for producing a thionucleoside, and the production method of the present invention is useful as a method for producing a thionucleoside.

Abstract: The object of the present invention is to provide a compound which is useful as a production intermediate of pyrazine carboxamide derivative such as 6-fluoro-3-hydroxy-2-pyrazine carboxamide. The present invention provides a pyrazino[2,3-d]isoxazole derivative represented by the formula (I): wherein X represents a halogen atom, a hydroxyl group or a sulfamoyloxy group, and Y represents —C(?O)R or —CN; wherein R represents a hydrogen atom, an alkoxy group an aryloxy group, an alkyl group, an aryl group or an amino group.

Abstract: A compound represented by a formula [1D] as shown below (wherein R1A, R1B, R2A, R2B, R3A and R3B represent a hydrogen atom, an optionally substituted C1-6 alkyl group, and the like) is useful as an intermediate for producing a thionucleoside, and the production method of the present invention is useful as a method for producing a thionucleoside.

Abstract: The object of the present invention is to provide a compound which is useful as a production intermediate of pyrazine carboxamide derivative such as 6-fluoro-3-hydroxy-2-pyrazine carboxamide. The present invention provides a pyrazino[2,3-d]isoxazole derivative represented by the formula (I): wherein X represents a halogen atom, a hydroxyl group or a sulfamoyloxy group, and Y represents —C(?O)R or —CN; wherein R represents a hydrogen atom, an alkoxy group an aryloxy group, an alkyl group, an aryl group or an amino group.

Abstract: The object of the present invention is to provide a compound which is useful as a production intermediate of pyrazine carboxamide derivative such as 6-fluoro-3-hydroxy-2-pyrazine carboxamide. The present invention provides a pyrazino[2,3-d]isoxazole derivative represented by the formula (I): wherein X represents a halogen atom, a hydroxyl group or a sulfamoyloxy group, and Y represents —C(?O)R or —CN; wherein R represents a hydrogen atom, an alkoxy group an aryloxy group, an alkyl group, an aryl group or an amino group.

Abstract: The object of the present invention is to provide a compound which is useful as a production intermediate of pyrazine carboxamide derivative such as 6-fluoro-3-hydroxy-2-pyrazine carboxamide. The present invention provides a pyrazino[2,3-d]isoxazole derivative represented by the formula (I): wherein X represents a halogen atom, a hydroxyl group or a sulfamoyloxy group, and Y represents —C(?O)R or —CN; wherein R represents a hydrogen atom, an alkoxy group an aryloxy group, an alkyl group, an aryl group or an amino group.

Abstract: A method for optical measurement of a multi-stranded nucleic acid which comprises the step of bringing a compound into contact with a multi-stranded nucleic acid wherein said compound is capable of interacting with the multi-stranded nucleic acid, wherein the compound has the following properties: (a) the compound can exist in a substantially colorless and non-fluorescent state under at least one condition in an aqueous solution in the absence of the multi-stranded nucleic acid, and (b) when the multi-stranded nucleic acid is allowed to exist in the condition defined in the above (a), the compound changes to a substantially colored state based on an interaction with the multi-stranded nucleic acid and substantially expresses fluorescent property based on said interaction.

Abstract: The present invention provides a method for detecting fluorescence by using a solid support to which a probe molecule to be detected is fixed, wherein background is reduced by using a quenching agent. By using present invention, detection sensitivity of a DNA chip can be increased and stable data can be obtained.