Conformationally rigid nucleoside probes help understand the role of sugar pucker and nucleobase orientation in the thrombin-binding aptamer URL: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2761269/?tool=pubmed Authors: Saneyoshi, / Mazzini, / Aviñó, / Portella, / González, Cecilia / Orozco, Modesto / Marquez, VE / Eritja,