Studies of the role of proton relays in molecular catalysts for the electrocatalytic production and oxidation of H(2) have been carried out. The electrochemical production of hydrogen from protonated DMF solutions catalyzed by [Ni(P(2)(Ph)N(2)(Ph))(2)(CH(3)CN)](BF(4))(2), 3a (where P(2)(Ph)N(2)(Ph) is 1,3,5,7-tetraphenyl-1,5-diaza-3,7-diphosphacyclooctane), permits a limiting value of the H(2) ...

During orthodontic treatment, root resorption can occur unexplainably. No clear distinction has been made between resorption located within specific regions and resorption occurring generally in the dentition. The purpose is to present cases with idiopathic (of unknown origin) root resorption occurring regionally. Two cases of female patients, 26 and 28 years old, referred with aggressive root ...

A facile and efficient one-pot synthesis of pyrrolidines and dispiro pyrrolidines/pyrrolizidines has been accomplished by the 1,3-dipolar cycloaddtion reaction of azomethine ylides generated insitu from paraformaldehyde/ninhydrin and secondary amino acids with electron-deficient dipolarophiles in good yield. The reaction proceeded with high regio and stereoselectivity. The products have been ch...