(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.
Unpleasant
Definition:
(a.) Not pleasant; not amiable or agreeable; displeasing; offensive.
Example Sentences:
(1) In the ketamine group, 36% of the patients complained of unpleasant dreams.
(2) Facial expression, EEG, and self-report of subjective emotional experience were recorded while subjects individually watched both pleasant and unpleasant films.
(3) The subjects described the thirst sensations as mainly due to a dry unpleasant tasting mouth, which was promptly relieved by drinking.
(4) It is no wonder that these visits can be stressful and unpleasant.
(5) Jonathan Rees, who was yesterday cleared of murdering his former business partner, Daniel Morgan, is a private investigator of a particularly unpleasant and vindicative kind.
(6) The lack of clinical activity and the unpleasant adverse effects in this population of patients with previously treated cervix cancer makes it unlikely that this drug will play any significant role in treatment.
(7) It must be very unpleasant to find out you’ve violated a brilliant artist whose public performance about you has drawn international attention and widespread support.
(8) In its infancy, the movement against censorship agitated on behalf of artists, iconoclasts, talented blasphemers; against repressive forces whose unpleasantness only confirmed which side was in the right.
(9) Before and after the experiment subjects were required to answer a questionnaire concerned with their image and attitude toward computers and the degree to which the task of typing is unpleasant.
(10) In our experience intestinal bypass, though resulting in significant weight loss, is associated with a number of unpleasant complications.
(11) "If you told them that some ... warheads were going to be dropped there and that it would be a very unpleasant place to go, they would not go there."
(12) In a joint statement the chapels said:"It shows management's utter disregard for the loyalty and dedication that their staff show every day in their efforts to produce quality newspapers and magazines, and sends out a deeply unpleasant message: no matter your experience or your commitment, everything is rated by cost."
(13) High problem severity was primarily associated with drinking in response to unpleasant affect and the belief that alcohol enhances social behavior.
(14) In an attitude survey of pregnant women 77% believed that vaginal examination was reassuring, 55% found it unpleasant, and 18% thought it could cause miscarriage.
(15) Cold pressor stimulation consisted of forearm immersion in a circulating water bath maintained at 0-1 degrees C. Subjects made threshold determinations of pain and tolerance and used Visual Analogue Scales to rate the strength and the unpleasantness of both noxious stimuli before and after receiving either hypnosis- or relaxation-induced analgesia.
(16) What's impressive is Cole's unfailing good cheer in the face of so much unpleasantness.
(17) It’s not as smelly as people imagine (myth number three), but it is still unpleasant, especially when the space is this confined, and one of the men tells me he reckons they are underpaid for what they do.
(18) Lidocaine (20 mg IV) will significantly reduce the incidence and severity of pain with propofol injection, but about 6% of patients will still suffer unpleasant pain if the dorsum of the hand is used.
(19) Both normal controls and left brain-damaged patients often averted their gaze from the screen when unpleasant material was displayed, whereas right brain-damaged patients rarely showed gaze aversion.
(20) However, all 8 subjects had unpleasant nasal symptoms following chlormethiazole, and it is therefore not an ideal hypnotic for this age group.