Accuracy and convergence of higher order distorted wave perturbation theory

A distorted wave perturbation theory which allows for a different distortion potential for each channel is investigated. The method is closely related to a perturbative solution of close coupled equations. Improvement in first order is found. However, higher order terms are not significantly improved over other computationally more convenient approaches. For purposes of comparison, numerical results are given for the oscillator atom collinear collision. The convergence of series solutions is studied as a function of scattering parameters. The accuracy of several approximation schemes is also investigated.     

Efficient Hydrolysis of RNA by a PNA - Diethylenetriamine Adduct

The introduction of a urea bond linking a protected diethylenetriamine (DETA) unit and the terminal amino group of a resin-bound peptide nucleic acid (PNA) decamer gave access to a PNA - DETA adduct (shown here), which hydrolyzed the target 25-mer RNA rapidly and sequence specifically.