Mononuclear η (4e)-Bonded Phosphaalkyne Complexes; Selective Formation of a 1,2-Diphosphacyclobutadiene Tantalum Complex.

Only the 1,2-diphosphacyclobutadiene and none of its 1,3 isomer was obtained in the reaction of 1 with tBuC≡P to give 2. In complex 1, which was prepared from [TaCl (η -C Me )(CO) (thf)] and tBuC≡P, the phosphaalkyne adopts an η (4e) bonding mode according to NMR data, crystal structure analysis, and theoretical calculations.

The ligand-receptor-G-protein ternary complex as a GTP-synthase. steady-state proton pumping and dose-response relationships for beta -adrenoceptors.

Steady-state solutions are developed for the rate of G alpha.GTP production in a synthase model of the ligand-receptor-G-protein ternary complex activated by a ligand-receptor proton pumping mechanism. The effective rate, k(31), defining the proton transfer, phosphorylation and G alpha.

Fluorescence monitoring of antibiotic-induced bacterial damage using flow cytometry.

Background: Conventional techniques used to assess bactericidal activities of antibodies are time-consuming; flow cytometry has been used as a rapid alternative. In this study, the membrane potential-sensitive fluorescent probes bis-(1,3-dibutylbarbituric acid) trimethine oxonol (DiBAC4(3)) and Sytox Green, the redox dye cyano-2,3-ditolyl tetrazolium chloride (CTC), and the Baclite viability test kit were used to assess the effects of ceftazidime, ampicillin, and vancomycin on clinical isolates of Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus, respectively.

Methods: Bacterial cultures were grown to early exponential phase, at which point the antibiotics were added at their breakpoint values, and incubation was allowed to continue.

A 13C-NMR study of the mechanism of bacterial metabolism of monomethyl sulfate.

Two different mechanisms have been proposed previously for initiating the biodegradation of monomethyl sulfate (MeSO4) in bacteria. For a Hyphomicrobium species, a sulfatase enzyme has been proposed to hydrolyse MeSO4 to methanol and inorganic sulfate. For an Agrobacterium sp.