Abstract: Provided is an acrylamide compound, which is useful for the promotion of platelet production from platelet progenitor cells such as megakaryocytes in vitro and represented by general formula [I]: wherein each symbol is as defined in the description.

Abstract: Provided is a novel heterocyclic compound having an aryl hydrocarbon receptor antagonist activity and useful for the promotion of platelet production, the compound being represented by the general formula [I]: wherein ring A, ring B, R1, R2, R3, R4, n, and X are as defined above, or a salt thereof.

Abstract: A digital work utilization monitoring method and system for preventing illegal use such as unpermitted copying of digital works so that use of the digital works can be monitored by judging whether or not the use is legally permitted and for facilitating a smooth and appropriate circulation of digital works by promoting payments of use fees for use of digital works. A use license is issued on the basis of a permission application for using a digital work and the license is embedded into the digital work by means of a digital watermark. With the license having an identification code of a device used by a user, it is judged whether or not the use of the distributed digital work is legally permitted by monitoring. The license can be issued on condition that a use fee has been paid.