The invention provides a pickup head used in an optical data storage system. Each nozzle has first circuitry of a first type arranged asymmetrically to second circuitry of a second type. 05 to 10 MDa; applying the sample to an anion-exchange chromatography column so as to immobilize the polysaccharide to the column; eluting the immobilized polysaccharide while recording a chromatogram of the amount of polysaccharide eluted as a function of time; and determining the molecular weight distribution in the polysaccharide sample through analysis of the chromatogram. The nonwoven fabric made of filament has heat shrinkage of 1 percent or less at 120 C. The void content of the molded article is 10 to 60%, and the bulk density thereof is 0. In yet another preferred mode, the agent is administered in an amount sufficient to increase malonyl CoA level.