Alternating, multi-block supramolecular copolymers were created using quadruple hydrogen bonding as the noncovalent binding force. One block consisted of two guanosine butyl urea (UG) units attached at the ends of a triethylene glycol linker or a PEG chain (MW = 2 kD). The other block contained a 2,7-diamido-1,8-naphthyridine (DAN) unit at each end of a short alkane diester linker or a 100 kD p...

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Mivacurium chloride (BW B1090U) is a new, short-acting non-depolarizing neuromuscular blocking agent. It is a synthetic bis-benzylisoquinolinium diester, which is hydrolysed rapidly by plasma cholinesterase. This study compares mivacurium, atracurium and vecuronium by continuous i.v. infusion. The duration of mivacurium infusion ranged from 29.5 to 286 min. The steady state infusion rates neces...

m-Aminophenylboronate-substituted agarose binds specifically RNA chains carrying a mature 5' cap. The binding occurs most effectively at pH greater than 8 and involves diester formation between the negatively charged tetrahedric boronate group and the cisdiol of the ribose of the cap. The positive charge introduced by the m7G methylation is necessary for efficient binding although two closely s...

Thin-layer systems for argentation chromatography of fatty-acid esters of carotenoids have been developed. As two-dimensional reversed-phase partition system on paraffine impregnated cellulose this method permits a clear discrimination between saturated and unsaturated fatty acids. By adsorption on silver nitrate containing silica gel-G separation of carotenoid esters according to the degree of...

Enzyme-catalyzed phosphoryl transfer reactions have frequently been suggested to proceed through transition states that are altered from their solution counterparts. Previous work with Escherichia coli alkaline phosphatase (AP), however, suggests that this enzyme catalyzes the hydrolysis of phosphate monoesters through a loose, dissociative transition state, similar to that in solution. AP also...

BACKGROUND Field trapping experiments were conducted to evaluate the attractiveness of five different pheromone blends as well as the impact of trap design on attractiveness towards cocoa mirids, Sahlbergella singularis Hagl. and Distantiella theobroma (Dist.), in Cameroon. RESULTS A total of 361 adults of S. singularis (359 males and two females) were caught. The highest numbers of mirids we...