To provide a novel preventive andor therapeutic agent against a virus, disclosed is a preventive andor therapeutic agent against a viral infection containing geranyl-geranyl acetone as an active ingredient. The change in the output frequency provides an indication of a change in a measurement parameter. The base member and the cover member each have a plurality of apertures defined in adjacent side walls that allow the horizontal latch arm to extend through the assembly. Thus, for example, a cold acid alkylation using an oligomer of isobutene with isobutane produces isooctane with the isobutane reacting with the constituent isobutene units of the oligomers on a molar basis.