Polyether antibiotics are a large class of microbial secondary metabolites generally produced by soil actinomycetes of the genus Streptomyces'). Intensive search for new polyether antibiotics has in recent years revealed that other genera of streptomycetes also produce these antibiotics. Laidlomycin is produced by Streptoverticillum eurocidium'). Cationomycin'), antibiotics CP-47,433 and CP-47,...

Turbine oil plays an important role in supporting optimal steam turbine performance. Some additives in turbine oil can cause emulsification when the oil is contaminated by water, so demulsibility is a very important property of the steam turbine oil. In order to improve the demulsibility of steam turbine oil, two kinds of polyether-silicone comb copolymers are synthesized and used as steam turb...

It has long been recognised that nest depredation by olfactory-searching mammals greatly influences the reproductive success of ground-nesting birds. Yet adaptations of birds to diminish smell during nesting have rarely been investigated. Recently, a remarkable shift in the composition of uropygial gland secretions (preen waxes) was discovered in many ground-nesting shorebirds and ducks that be...

BACKGROUND Ciguatera is a circumtropical disease produced by polyether sodium channel toxins (ciguatoxins) that enter the marine food chain and accumulate in otherwise edible fish. Ciguatoxins, as well as potent water-soluble polyethers known as maitotoxins, are produced by certain dinoflagellate species in the genus Gambierdiscus and Fukuyoa spp. in the Pacific but little is known of the poten...

OBJECTIVE The aim of this study was 2-fold. The first aim was to evaluate the effects of mixing technique (hand-mixing or auto-mixing) on bacterial attachment to polyether impression materials. The second aim was to determine whether bacterial attachment to these materials was affected by length of exposure to disinfection solutions. MATERIALS AND METHODS Polyether impression material samples...

Thermoplastic polyamide elastomer (PAE) [also PEBA: polyether block amide] is one of the most recently developed of the thermoplastic elastomers: a multiblock polymer with polyamide hard segments, it uses longchain polyether diol or polyester diol of low Tg for its soft segments. Polyamide 6 or polyamide 12 (PA12) is the main polyamide component used, while the soft segments are mostly provided...

AIM To evaluate the biocompatibility of a resin-based endodontic filler (RealSeal) using the indirect cytotoxicity test. METHODOLOGY Human gingival fibroblasts were cultured ex vivo. Pellets of the materials to be tested were incubated for 24, 48, and 72 h at 37 degrees C under sterile conditions to obtain their eluates. The fibroblasts were exposed to either diluted (50%) or undiluted eluate...

Objective. To investigate the accuracy of dies obtained from single-step and 2-step double-mix impressions. Material and Methods. Impressions (n = 10) of a stainless steel die simulating a complete crown preparation were performed using a polyether (Impregum Soft Heavy and Light body) and a vinyl polysiloxane (Perfectim Blue Velvet and Flexi-Velvet) in two consistencies, in one or two (without ...

Phosphorothioate diester oligonucleotides proved to be fully compatible with maleimides in the context of two different conjugation reactions: (a) reaction of (5')diene-[phosphorothioate oligonucleotides] with maleimido-containing compounds to afford the Diels-Alder cycloadduct; (b) conjugation of (5')maleimido-[phosphorothioate oligonucleotides] with thiol-containing compounds. No evidence of ...

Quinizarin diester is used as a fluoro-chromogenic substrate of the activity of lipase supported in poly(methylmetacrylate) beads (CALB, Novozym® 435) dispersed in organic solvents. The monoester and diester of quinizarin are both non-fluorescent species contrasting with the enzymatic product quinizarin that shows optical absorption in the visible region and strong fluorescence signal. The enzy...