Abstract: A method produces a hairpin single-stranded RNA molecule capable of inhibiting expression of a target gene, including the step of reacting a first single-stranded oligo-RNA molecule represented by formula (I) with a second single-stranded oligo-RNA molecule represented by formula (II) in a mixed solvent including a buffer solution and a hydrophilic organic solvent in the presence of a dehydration condensation agent: 5?-Xc-Lx1 . . . (I) and Lx2-X—Y-Ly-Yc-3? . . . (II), wherein the dehydration condensation agent is selected from the group consisting of a triazine-based dehydration condensation agent, a uronium-based dehydration condensation agent including an N-hydroxy nitrogen-containing aromatic ring structure, a carbodiimide-based dehydration condensation agent, a 2-halopyridinium-based dehydration condensation agent, and a formamidinium-based dehydration condensation agent.

Abstract: The present invention intends to provide a surface combustion burner which can permit high intensity combustion at the burner surface by preventing the occurrence of a lift phenomenon of flames due to whirling of air from the peripheral portion of the surface combustion burner. To this end, a mixing chamber positioned rearwardly of a porous member having its front surface constituting a combustion surface is divided by a partition wall into a first mixing chamber positioned at a central portion and a second mixing chamber positioned to surround the first mixing chamber so that fuel gas mixtures at different air ratios are supplied to the first and second mixing chambers, respectively, and/or the porous member having its front surface serving as the combustion surface has a resistance against the flow velocity of fuel gas mixture which is higher at a peripheral edge nearby region than at the remaining region.