Catalytic, asymmetric alpha-halogenation.
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Biomedical subjects
Publications and source records attributed to W J Drury.
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[structure] A catalytic asymmetric reaction process was designed involving the use of solid-phase reagents and catalysts that constitute the packing of a series of "reaction columns". This process was applied to the catalytic asymmetric synthesis of beta-lactams, yielding pure product after crystallization with exceptional enantio- and diastereoselectivity.
[formula: see text] Catalytic acylation using complex transition metal salts MCo(CO)4 is demonstrated. Surprisingly, a solvent-dependent mechanistic "switch" results in a Lewis acid-based acylation mechanism in nonpolar media and a nucleophilic mechanism in polar organic media. These observations lead to the first example of a catalyzed Staudinger reaction to form beta-lactams.
Heterogeneity in a Pseudomonas aeruginosa biofilm was quantified by measuring distributions of thickness in biofilm samples and a distribution of particle sizes in effluent samples. The mean steady-state thickness was approximately 33 microns, but individual measurements ranged from 13.3 to 60.0 microns. Particles exceeding 100 microns3 were observed in the reactor effluent. The results reveal a rough biofilm surface and indicate that most biomass detaches in the form of multicellular particles.
Sixty-four adult patients (87 diaphyseal forearm fractures) were treated by plating. Thirty-nine percent of the fractures were classified as single bone fractures (16% radius, 23% ulna); 43% were both radial and ulnar fractures, and 19% were Galeazzi or Monteggia fracture-dislocations. A major complication occurred in 18 (28%) patients. Nonunion occurred in six patients: three of 18 bones treated with four screws (17%), but only three of 69 bones fixed with five or more screws (4.3%), a nonunion rate four times higher for bones plated with four screws. Screws loosened in three fractures, all involving the ulna. Radioulnar synostosis occurred in seven forearms, and in five of these the forearm injuries were associated with multiple system trauma involving head injury. Two patients had osteomyelitis. Both were victims of massive crush injury and delayed internal fixation, and both required removal of the implant; but eventually the fractures healed. Plate fixation of forearm fractures can have a high complication rate. Meticulous attention to surgical technique and the use of plates long enough to provide secure fixation can not be overemphasized. An increased incidence of synostosis in polytrauma, head-injured patients was noteworthy.