The concept of weak algebraic hyperstructures or Hv-structures constitutes a generalization of the well-known algebraic hyperstructures (semihypergroup, hypergroup and so on). The overall aim of this paper is to present an introduction to some of the results, methods and ideas about chemical examples of weak algebraic hyperstructures. In this paper after an introduction of basic definitions and...

This article describes the formation of reactive oxygen species as a result of the oxidation of dissolved sulfide by Fe(III)-containing sediments suspended in oxygenated seawater over the pH range 7.00 and 8.25. Sediment samples were obtained from across the coastal littoral zone in South Carolina, US, at locations from the beach edge to the forested edge of a Spartina dominated estuarine salt ...

Elicitation of cultured chickpea (Cicer arietinum L.) cells stimulates a signal transduction pathway leading to several rapid responses: (1) oxidative burst, (2) extracellular alkalinisation, (3) extracellular acidification, (4) transient K+ efflux, and (5) activation of defence related genes all within 2 hours. Induced genes are encoding acidic and basic chitinases, a thaumatin-like protein an...

Based on the recently derived general expression for the rates of diffusion-controlled reactions, we calculate the rates of dismutation of the superoxide anion radical catalyzed by Cu/Zn superoxide dismutases (SOD). This is the first attempt to calculate the absolute rates of diffusion-controlled enzyme reactions based on the atomiclevel molecular dynamics simulations. All solvent molecules are...

The reduction of cytochrome c by xanthine oxidase and the competitive inhibition of this process by carbonic anhydrase and by myoglobin have been studied by kinetic and by equilibrium binding methods. Carbonic anhydrases isolated from bovine and from human erythrocytes differed strikingly in their ability to inhibit competitively the reduction of cytochrome c. The KS for cytochrome c was a func...

An abnormal N-heterocyclic carbene (aNHC) has been used as a Lewis base to initiate dismutation of trichlorosilane. This report presents the reactivity differences of a normal N-heterocyclic carbene (NHC) versus aNHCwith heavier group 14 elements. Three novel compounds (NHC)2 SiCl2H2 (2), aNHC SiCl2H2 (3), and aNHC GeCl2 (4) have been synthesized and characterized by single crystal X-ray analys...

An abnormal N-heterocyclic carbene (aNHC) has been used as a Lewis base to initiate dismutation of trichlorosilane. This report presents the reactivity differences of a normal N-heterocyclic carbene (NHC) versus aNHC with heavier group 14 elements. Three novel compounds (NHC)(2)·SiCl(2)H(2) (2), aNHC·SiCl(2)H(2) (3), and aNHC·GeCl(2) (4) have been synthesized and characterized by single crystal...

Riboflavin synthase catalyses a mechanistically complex dismutation affording riboflavin and 5-amino-6-ribitylamino-2,4(1H,3H )-pyrimidinedione from 6,7-dimethyl-8-ribityllumazine. A pentacyclic adduct (compound 2 ) of two substrate molecules was used as substrate for pre-steady-state kinetic analysis. Whereas the wild-type enzyme catalyses the decomposition of compound 2 into a mixture of ribo...