Abstract: The light-absorbing composition according to the present invention includes: a light absorber made of a phosphonic acid represented by the following formula (A) and copper ion; and a curable resin. Alight-absorbing film having desired properties can be provided by curing a coating film of the light-absorbing composition. In the formula (A), R1 to R5 are each independently a hydrogen atom, a halogen atom, a hydroxy group, or a nitro group, and n represents an integer of 1 to 3.

Abstract: A light-absorbing composition according to the present invention includes: a light absorber; a curable resin; and an alkoxysilane. The alkoxysilane includes a dialkoxysilane. Since the alkoxysilane of the light-absorbing composition includes the dialkoxysilane, desired flexibility is likely to be imparted to a light-absorbing layer owing to an organic functional group of the dialkoxysilane while a strong skeleton having a siloxane bond is formed in the light-absorbing layer.

Abstract: The liquid composition for optical filters according to the present invention contains: a light absorber; at least one of an alkoxysilane and a hydrolysate of an alkoxysilane; a phosphoric acid ester; and a solvent. The light absorber is formed by a phosphonic acid having an aryl group bonded to a phosphorus atom and copper ion. In the liquid composition, a content of an organic solvent having a relative permittivity of 7 or less at 20° C. is 50 mass % or less.

Abstract: The present invention provides a method for testing mesothelioma comprising a step of determining a concentration of a human periostin protein in at least one type of sample of blood or pleural fluid of a subject. In the step of determining the concentration of human periostin protein, an antibody directed against human periostin protein may be used. The present invention further provides a kit for diagnosing mesothelioma, said kit comprising an antibody directed against human periostin protein. In the kit for diagnosing mesothelioma, the antibody directed against a human periostin protein may be an antibody that binds to a polypeptide consisting of an amino acid sequence set out in SE ID NO: 2.