(n.) A gaseous compound of carbon and hydrogen, in the proportion of two atoms of the former to two of the latter. It is a colorless gas, with a peculiar, unpleasant odor, and is produced for use as an illuminating gas in a number of ways, but chiefly by the action of water on calcium carbide. Its light is very brilliant.
Example Sentences:
(1) Optimum rates of acetylene reduction in short-term assays occurred at 20% O2 (0.2 atm (1 atm = 101.325 kPa] in the gas phase.
(2) On siratro, CIAT899 induced nodules that were ineffective in acetylene reduction, whereas the EPS-deficient mutants induced effective nodules.
(3) It is suggested that acetylene reduction assays may not be accurately applied to samples containing methane oxidizing bacteria.
(4) Biological nitrogen fixation, as determined by acetylene reduction, occurs in Lake Erie.
(5) Some of the thiophenes and their acetylenic derivatives possess extremely potent phototoxic activities toward membrane-containing viruses.
(6) The efficiencies of the different positional isomers in supporting cell proliferation varied from essentially 0 cells per fmol for the 2-5 and 13-17 isomers to high values when the acetylenic bond was near the center of the chain: e.g.
(7) If the cultures were grown in media with NH4+, NO3-, urea, glutamine or asparagine, hydrogen photoevolution by the cells and acetylene reduction started after the lag-phase and proceeded at a low rate.
(8) Under suitable growth conditions the acetylenic acids are catabolized and partly reused via acetate for de novo synthesis of fatty acids.
(9) 2-Ethynyl-4,5-diphenylthiazoles were synthesized by the palladium catalyst cross-coupling reaction of 2-iodo-4,5-diphenylthiazole with monosubstituted acetylenes.
(10) The conditions which are necessary for the synthesis and function of this system were studied in whole cells by using acetylene reduction as a sensitive assay for the presence of the N(2)-fixing system.
(11) However, in culture under aerobic conditions, large, phase-bright vesicles are formed in HFPCcI3 within 20 h following removal of NH+4 from the culture medium and reach peak numbers within 72 to 96 h. In vivo acetylene reduction activity parallels vesicle formation.
(12) Vesicles permeabilized by freeze-thaw or detergents showed increased rates of acetylene reduction due to increased permeability of dithionite.
(13) After 30 minutes at this new driving force, four timed acetylene samples were again collected.
(14) 3-(1,2,3-Triazol-1-yl)methylcephalosporins have been prepared by the direct cycloaddition of acetylene to 3-azidomethylcephalosporins, which were obtained by nucleophilic substitution of 3-chloromethylcephalosporins with sodium azide in N,N-dimethylformamide.
(15) Biological dinitrogen fixation in mangrove communities of the Tampa Bay region of South Florida was investigated using the acetylene reduction technique.
(16) Nitrate reductase (nar) A, B and E mutants of Escherichia coli with plasmids carrying Klebsiella pneumoniae nitrogen fixation (nif) genes reduced acetylene independently of added molybdate, but nar D mutants showed pleiotropic dependence on the concentration of added molybdate for expression of both nar and nif.
(17) Two important side reactions of this procedure are known: the formation of the isomeric beta-ethynyl derivative and the formation of a dimeric product with acetylene bridge.
(18) Acetylene-reducing activity of purified nitrogenase from Klebsiella pneumoniae was studied over a range of ATP and Mg(2+) concentrations at 15 degrees C, pH7.8.
(19) The reconstituted acid mixture is injected into the graphite tube atomizer for analysis of Cu and Cd and aspirated into the air--acetylene flame for measurement of Zn.
(20) The 19-acetylenic testosterone, a confirmed metabolite from primate studies, was 25% as efficient as MDL 18,962 for aromatase inactivation, while 6 beta-hydroxy- and 6-oxo analogs were 11% and 5%, respectively as efficient as their parent compound.
Odour
Definition:
Example Sentences:
(1) Employed method of observation gave quantitative information about the influence of odours on ratios of basic predeterminate activities, insect distribution pattern and their tendency to choose zones with an odour.
(2) There was a clear relationship between the receptor responses and odour concentration.
(3) produced strong rotten, fishy, hydrogen sulphide off-odours.
(4) This may be managed in future by an odour-reducing minimal APS-addition under a 2%-application.
(5) • Rules requiring local authorities to investigate and abate noise, dust and odour nuisances will be liberalised or improved.
(6) Distinction was made between different types of odours (rotten, wood).
(7) These laboratory bioassay findings agree with field observations on tsetse responses to certain chemical odours.
(8) A substantial improvement in the rate of detection of organic lesions affecting the olfactory pathway can be achieved by substituting odours such as musk ketone, exaltolide, linalyl acetate and coumarin for those in current use.
(9) One month later the subjects underwent a second recognition test, at the end of which they were required to give an evaluation of the pleasantness of each odour on a nine-point scale.
(10) Diluted DOMESTOS proved to be a cleaning agent and germicide, but was, however, blamed for chlorine odour, especially when diluted with warm water.
(11) The patient developed a characteristic fish odour of his sweat, urine and to his breath after the consumption of choline-rich foods.
(12) Only ACB produced classical musk-like UAO (UAO + ve) in an in vitro odour-producing system with 29% being UAO -ve.
(13) Effective stimuli were the odours of cattle and sheep and high concentrations of carbon dioxide from dry ice.
(14) A fast method for such comparisons, based on volume matching followed by the estimation of comparable surface dots, is presented and applied on a few selected sandalwood odour molecules.
(15) The plug is made of a soft, pliable plastic material with open cells, containing a carbon filter which allows flatus to pass odour-free.
(16) This study examines the effect of synthetic cattle-derived odours, presented with Communicable Diseases Centre (CDC) miniature light traps for mosquitoes and also with sticky traps for sandflies, in Sri Lanka.
(17) A statistical significant training effect could be shown with the qualitative test for training of the odour memory as well as the articulation in describing of smell impressions.
(18) The results were analysed from two viewpoints: the role of odour as a warning against chemical hazard, a possibility of using the shift of sensation threshold of appropriately selected reference standards as a measure of discomfort created by odours in working environment.
(19) The activities of 45 RRUs were analyzed during sniffing in response to an odour stimulus.
(20) The maturation of the granule cells of the ferret olfactory bulb around the time of odour imprinting has been examined.