For any root system and any commutative ring, we give a relatively simple presentation of a group related to its Steinberg group St. This includes the case of infinite root systems used in Kac–Moody theory, for which the Steinberg group was defined by Tits and Morita–Rehmann. In most cases, our group equals St, giving a presentation with many advantages over the usual presentation of St. This e...

We obtain a criterion for quasiconvexity of a subgroup of an amalgamated free product of two word hyperbolic groups along a virtually cyclic subgroup. The result provides a method of constructing new word hyperbolic group in class (Q), that is such that all their finitely generated subgroups are quasiconvex. It is known that free groups, hyperbolic surface groups and most 3-dimensional Kleinian...

Sulfonamide resonant biologically active enaminone derivatives 3, 5, and quinolone derivative 8 have been created. Correspondingly, the thiazoloquinazoline derivative 13 was acquired in decent yield via reaction of 2-isothiocyanate derivative 9 with the L-nor ephedrine 10. The assemblies of the prepared amalgams stood established by microanalysis, IR, 1H-NMR, 13C-NMR and mass spectral informati...

AIMS To establish and analyse reference data for the mercury burden of patients with and without amalgam fillings. METHODS Atomic absorption spectroscopy was used to quantify Hg concentrations in the scalp hair and urine (before and after application of dimercaptopropane sulphonate), and Hg release from dental amalgams (using a newly developed, amalgam specific chew test), in 2223 subjects. ...