Embodiments of photoanodes and quantum dot-sensitized solar cells comprising colloidal, cation-exchanged quantum dots are disclosed. A down-converter 121 frequency-down-converts analog signal Sm. The first semiconductor layer is in contact with the gate insulating layer. A motion vector with the least cost may be selected and motion compensated to generate a plurality of interpolated pictures. In each pair, the power switching element in a high voltage side and the power switching element in a low voltage side are connected in series. The present invention also provides methods of extranuclear RNA splicing, and methods of protein translation based on extranuclear RNA splicing.