Pulse signal vs MD time. (a) Pulse outputs of the H-bond distance changes in the nucleotide base pairs C3---G22, G4---C21, A5---T20, A6---T19 and T7---A18. (b) Pulse outputs of the distance between the stacked nucleobases A18---T19, T19---T20 and T20---C21. Each nucleic acid sequence shows a distinct signal pattern.