Abstract: In the present invention, a sequence segment conforming to the following rules (a) to (d) is searched from the base sequences of a target gene of RNA interference and, based on the search results, siRNA capable of causing RNAi is designed, synthesized, etc.: (a) The 3? end base is adenine, thymine, or uracil, (b) The 5? end base is guanine or cytosine, (c) A 7-base sequence from the 3? end is rich in one or more types of bases selected from the group consisting of adenine, thymine, and uracil, and (d) The number of bases is within a range that allows RNA interference to occur without causing cytotoxicity.

Abstract: The tool for contemplation comprises a paper on which a main unit and a sub unit that surrounds the main unit are printed. The main unit includes a subject display cell that displays a subject and a plurality of thought results display cells that display a plurality of thought results found from the subject. Each sub unit includes a new subject display cell that displays each thought result as a new subject, and a plurality of new thought results display cells that surrounds the new subject display cell and that display a plurality of thought results found from the new subject. Thereby, the tool for contemplation enables readily seeing and utilizing a plurality of thought results found from a subject.