Solution structures of the i-motif tetramers of d(TCC), d(5methylCCT) and d(T5methylCC): novel NOE connections between amino protons and sugar protons

AbstractBackground: At slightly acid or even neutral pH, oligodeoxynucleotides that include a stretch of cytidines form a tetramer structure in which two parallel-stranded duplexes have their hemi-protonated C·C+ base pairs face-to-face and fully intercalated, in a so-called i-motif, first observed serendipitously in [d(TC5 )]4.Results A high-definition structure of [d(TCC)]4 was computed on the basis of inter-residue distances corresponding to 21 NOESY cross-peaks measured at short mixing times. A similarly defined structure of [d(5mCCT)]4 was also obtained. A small number of very characteristic (amino proton)-(sugar proton) cross-peaks entails the intercalation topology. The structure is generally similar to that of [d(TC5 )]4 . The sequence d(T5mCC) forms two tetramers in comparable proportions. The intercalation topologies are read off the two patterns of (amino proton)-(sugar proton) cross-peaks: one is the same as in the d(TCC) tetramer, the other has the intercalated strands shifted by one base, which avoids the steric hindrance between the methyl groups of the 5mC pairs of the two duplexes. .Conclusion The structures obtained in this work and the procedures introduced to characterize them and to solve the problems linked to the symmetry of the structure provide tools for further exploring the conditions required for formation of the i-motif

Terminal Base Pairs of Oligodeoxynucleotides: Imino Proton Exchange and Fraying

International audienc

Sodium Hydroxide as a Permian Clay-Gypsum Stabilizer

Civil Engineerin

Joseph Gantrelle Prize (42nd biennial period, 1976-1977). Report of the jury.

Attribution du prix Gantrelle à René Henry lors de la remise de prix éponyme de 1976-1977 par les jurés Claire Préaux, Maurice Leroy, Jules Labarbe et Léon Lacroix.Awarding of the Gantrelle prize to René Henry at the 1976-1977 eponymous award ceremony by the jurors Claire Préaux, Maurice Leroy, Jules Labarbe and Léon Lacroix

Laparoscopic surgery for groin hernia in a third world country: a report of 9 cases of transabdominal pre-peritoneal (TAPP) repair in Yaoundé, Cameroon

Groin hernia repair is probably the most common procedure in general surgery. Today, in adult hernias, prosthetic repairs are accepted to be superior to "non-mesh" suture repairs. Concerning mesh repair, the (open) LICHENSTEIN and laparoscopic inguinal hernia techniques are recommended as the best evidence-based options. Nevertheless laparoscopic repair techniques still not currently practiced in sub-Saharan countries and particularly in Cameroon. From January 2011 to November 2014, a prospective laparoscopic groin hernia-specific database was queried for all adult patients in the visceral and laparoscopic surgery unit of the National Insurance Health Center of Essos (Yaoundé/Cameroon). Seven patients were recorded. All of them were male with a mean age of 49 years. Two cases were bilateral, 5 unilateral and all of them primary. There were 6 direct and 3 indirect hernias. They underwent 9 Transabdominal Pre-peritoneal (TAPP) repair and none Totally Extra-Peritoneal (TEP) procedure was done. A self-gripping overlapping flap was inserted in all cases. The mean length of the procedure was decreasing with time, from 150 min for our first procedure to 60 minutes for the last one. With a mean follow-up period of 20.2 months, the post-operatives courses were uneventful. Laparoscopic hernia repair in general and TAPP in particularly is a safe and reproducible procedure even in developing countries. African surgeons should be aware of this technique.Pan African Medical Journal 2016; 2

Interurban car tests on the Illinois Traction System

Thesis (B.S.)--University of Illinois, 1905.Typescript.Leaves 31-37 contain folded charts