Abstract: An anthraquinone-based active material for a redox flow battery includes a first compound represented by the following chemical formula: where at least one of the R1 to R8 is a hydroxy group, and at least one of the R1 to R8 is an alkoxy group.

Abstract: A method of producing an anthraquinone-based substance represented by the following chemical formula: where at least one of R1 to R8 is a hydroxy group, and at least one of R1 to R8 is an alkoxy group, includes the steps of: preparing a starting material represented by the following chemical formula: where at least two of the R1? to R8? are hydroxy groups; and reacting the starting material with an organic alkylating agent. The amount of the organic alkylating agent to be reacted with the starting material is more than or equal to 0.05 mol and less than n mol per 1 mol of the starting material, where n is the number of hydroxy groups contained in the starting material.

Abstract: An object is to provide a surgical assistance device and a surgery support system that can ensure a sufficient field of view during an arthroscopic surgery. The object can be achieved by a surgical assistance device for capturing an image inside a body cavity. The surgical assistance device includes: N image capturing units; holding parts, each of the holding parts holding each of the image capturing units; and a base member, and N is an integer that is greater than or equal to three.

Abstract: A redox flow battery includes: a cell having a first chamber and a second chamber separated by a membrane; a first tank for storing a first electrolytic solution; a first circulation device for circulating the first electrolytic solution between the first chamber and the first tank; a second tank for storing a second electrolytic solution; and a second circulation device for circulating the second electrolytic solution between the second chamber and the second tank. Each of the first electrolytic solution and the second electrolytic solution contains an active material, and at least one of the active material contained in the first electrolytic solution or the active material contained in the second electrolytic solution is a quinone multimer in which a plurality of quinones are connected via an alkyl chain or a hydroquinone multimer in which a plurality of hydroquinones are connected an alkyl chain.