(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.
Propane
Definition:
(n.) A heavy gaseous hydrocarbon, C3H8, of the paraffin series, occurring naturally dissolved in crude petroleum, and also made artificially; -- called also propyl hydride.
Example Sentences:
(1) Stopped-flow studies of oxidation of butan-1-ol and propan-2-ol by NAD(+) in the presence of Phenol Red and large concentrations of yeast alcohol dehydrogenase give no evidence for the participation of a group of pK(a) approx.
(2) Young female rats dosed with 1-bromo[1-14C]propane excrete the same metabolites as adult females but in different relative proportions.
(3) The performance of a commercial double-propane-jet freezer (Balzers QFD 101) has been assessed, for rapid freezing of fresh tissues in freeze-etch work.
(4) The ryanodine receptor protein of sheep cardiac muscle sarcoplasmic reticulum membranes functions as a ligand-regulated ion channel following solubilization with the zwitterionic detergent CHAPS (3-[(3-cholamidopropyl)-dimethylammonio]-1- propane sulphonate); purification by density gradient centrifugation, reconstitution into proteo-liposomes and incorporation into planar phospholipid bilayers.
(5) The biliary excretion of metabolites of 1,2-epoxy-3-(p-nitrophenoxy)-propane is described.
(6) There is no detectable activity with 1,2-epoxy-3-(p-nitrophenoxy)propane, ethacrynic acid, p-nitrobenzyl chloride or p-nitrophenyl acetate.
(7) Clinical experience is reported with bis-dioxopiperazine propane (ICRF 159) in 20 children with acute leukaemia in relapse.
(8) A fast freezing technique using liquid propane was used to obtain frozen solutions of methemoglobin at pH 7.
(9) Substitution of "strong" salts in the sample zone with salts formed by weak acids and bases, e.g.. Tris-acetate, Tris-glycinate, Good's buffers such as (N-[2-acetamido]-2-iminodiacetic acid (ADA), (2-[(2-amino-2-oxoethyl)-amino] ethanesulfonic acid (ACES), (3-[N-morpholino]propane sulfonic acid (MOPS), essentially abolishes both phenomena, oxidation and irreversible denaturation.
(10) Results of the demonstration tests show that the system, which uses liquefied propane, successfully removed PCBs from contaminated sediments in New Bedford Harbor.
(11) The capacity of carnosine to decrease free radical-induced damage was evaluated using the oxidation of brain homogenates, the 2,2'-azobis-2-amidino propane-induced oxidation of erythrocyte ghost membranes, the radiation induced inactivation of horseradish peroxidase and the 2,2'-azobis-2-amidino propane-induced inactivation of lysozyme.
(12) Lignin peroxidase also hydroxylated 1-(4'-ethoxy-3'-methoxyphenyl)propane II at the alpha-position to yield 1-(4'-ethoxy-3'-methoxyphenyl)-1-hydroxypropane VI under anaerobic conditions in the presence of mCPBA.
(13) Derivatives of the antiallergic drug cromolyn [disodium 5,5'-[(2-hydroxy-1,3-propanediyl)-bis(oxy)]bis [4-oxo-(4H-1-benzopyran)-2- carboxylate]], which can be conjugated covalently at the propane 2-position to macromolecules and to insoluble matrices, were synthesized.
(14) The effect of two nitroimidazoles, 2-acetoxyl-1,3-bis-(2'-methyl-4'-nitro-1'-imidazolyl)propane (Rs-029) and 2-acetoxy-1-(2'-methyl-4'-nitro-1'-imidazolyl)-3-(2''-methyl-5''-nitro- 1- nitroimidazolyl)propane (Rs-034) on ATP level and erythrocyte membrane ATP-ase activity was studied.
(15) The animals were decapitated and, the pituitary glands were removed, mounted on tissue holders and frozen in liquified propane.
(16) macrosporus is a unique acid endopeptidase that is insensitive (or less sensitive) to specific inhibitors of ordinary acid or aspartic proteinases, such as pepstatin, diazoacetyl-DL-norleucine methyl ester, and 1,2-epoxy-3-(p-nitrophenoxy)-propane.
(17) Rapid quenching methods such as plunging a grid into liquid propane cooled by LN2 or collision with a clean surface of a copper block cooled to LHe temperature were used to avoid ice crystal formation.
(18) Considerable activity was obtained with 1-chlorl-2,4-dinitrobenzene and low activity with 3,4-dichloro-1-nitrobenzene, but no enzymic reaction was detectable with sulphobromophthalein 1,2-epoxy-3-(p-nitrophenoxy)propane of trans-4-phenylbut-3-en-2-one as substrates.
(19) When porcine brain membranes were solubilized with digitonin or 3-[(3-cholamidopropyl)dimethylammonio]-1-propane sulfonate (CHAPS), approximately 20% of the receptors were solubilized, most (90% or more) of which bound to Sepharose 4B conjugated with wheat germ agglutinin (WGA).
(20) Propane inhalation may be widespread, yet only a few cases have been reported.