(n.) A gaseous element, colorless, tasteless, and odorless, the lightest known substance, being fourteen and a half times lighter than air (hence its use in filling balloons), and over eleven thousand times lighter than water. It is very abundant, being an ingredient of water and of many other substances, especially those of animal or vegetable origin. It may by produced in many ways, but is chiefly obtained by the action of acids (as sulphuric) on metals, as zinc, iron, etc. It is very inflammable, and is an ingredient of coal gas and water gas. It is standard of chemical equivalents or combining weights, and also of valence, being the typical monad. Symbol H. Atomic weight 1.
Example Sentences:
(1) The hypothesis that proteins are critical targets in free radical mediated cytolysis was tested using U937 mononuclear phagocytes as targets and iron together with hydrogen peroxide to generate radicals.
(2) It has been conformed that catalase from bovine liver eliminates only the pro R hydrogen atom from ethanol.
(3) We investigated the possible contribution made by oropharyngeal microfloral fermentation of ingested carbohydrate to the generation of the early, transient exhaled breath hydrogen rise seen after carbohydrate ingestion.
(4) Hydrogen isotope effects on these mutants indicate that MotA catalyzes proton transfer.
(5) Excessive accumulation of hydrogen ions in the brain may play a pivotal role in initiating the necrosis seen in infarction and following hyperglycemic augmentation of ischemic brain damage.
(6) Studies were conducted in isolated, buffer-perfused rat lungs to determine if prostaglandin (PG) E1 attenuated pulmonary edema provoked by hydrogen peroxide (H2O2).
(7) All N and O atoms except N(3) and O(4') participate in a three-dimensional hydrogen-bonding system.
(8) Both adiphenine.HCl and proadifen.HCl form more stable complexes, suggesting that hydrogen bonding to the carbonyl oxygen by the hydroxyl-group on the rim of the CD ring could be an important contributor to the complexation.
(9) Control mutant S38N has stability essentially the same as that of wild-type lysozyme but hydrogen bonding similar to that of the stabilizing mutant S38D.
(10) High intensity ultrasound also enhances the heterogeneous catalysis of alkene hydrogenation by Ni powders.
(11) An atmosphere of hydrogen eliminates this inhibition in the hydrogenase-containing T. foetus but not in E. invadens which lacks the enzyme.
(12) Vanadate-dependent oxidation of either pyridine nucleotide was inhibited by the addition of either superoxide dismutase or catalase, indicating that both superoxide and hydrogen peroxide may be intermediates in the process.
(13) Our findings suggest that (a) the inclusion of a liquid meal provides a reproducible method of measuring orocaecal transit using the lactulose hydrogen breath test, (b) rapid small bowel transit in thyrotoxicosis may be one factor in the diarrhoea which is a feature of the disease and (c) if altered gut transit is the cause of sluggish bowel habit in hypothyroidism, delay in the colon, and not small bowel, is likely to be responsible.
(14) Stepwise hydrogenation of metal tetradehydrocorrin salts (10 double bonds) yields a series of macrocycles containing 9, 8, 7, 6 and 5 double bonds and conditions necessary to obtain corrins have been established.
(15) For dipeptides containing the amino terminal residues glycine, alanine and phenylalanine, abstraction of the hydrogen from the carbon adjacent to the peptide nitrogen was the major process leading to the spin-adducts.
(16) (7) The first-order radical transformation rates are independent of the (initial) concentration of N3 or peptide and unaffected by urea (as a modifier of hydrogen bond structures).
(17) Intermolecular contacts occur in both oligomers in the minor groove: in the B form through twisted guanine-guanine hydrogen bonding, and in the Z form through base-base stacking and the water network.
(18) Equilibrium-partitioning measurements indicate that the relative affinities of different probes for PC-rich vesicles, in competition with HODMA or DOTAP vesicles, increase with increasing hydrogen-bonding capacity of the probe headgroup in the order PC less than N,N-dimethyl PE less than N-methyl PE less than PE approximately phosphatidyl-2-amino-1-propanol.
(19) When tissue metabolism was irreversibly inhibited by exposure to formaldehyde, hydrogen ion concentration and pCO2 were significantly decreased in the mucosal side of the chamber compared with the viable gall bladder.
(20) Based on the refined atomic coordinates of the tRNAphe in the orthorhombic crystal, on the recent advances in the distance dependence of the ring-current magnetic field effects and on the adopted values for the isolated hydrogen-bonded NH resonances, a computed spectrum consisting of 23 protons was constructed.
Methane
Definition:
(n.) A light, colorless, gaseous, inflammable hydrocarbon, CH4; marsh gas. See Marsh gas, under Gas.
Example Sentences:
(1) A new type of Escherichia coli mutant which shows increased sensitivity to methyl methane sulfonate but not to UV light or to gamma rays was isolated after mutagenesis with N-methyl-N'-nitro-N-nitrosoguanidine.
(2) The possibility that mammalian DNA topoisomerase II is an intracellular target which mediates drug-induced DNA breaks is supported by the following studies using 4'-(9-acridinylamino)methane-sulfon-m-anisidide (m-AMSA): (a) a single m-AMSA-dependent DNA cleavage activity copurified with calf thymus DNA topoisomerase II activity at all chromatographic steps of the enzyme purification; (b) m-AMSA-induced DNA cleavage by this purified activity resulted in the covalent attachment of protein to the 5'-ends of the DNA via a tyrosyl phosphate bond.
(3) These parameters are compared with those of various model groups and compounds: CH2, peptide, methane, ethane, and the 1--13 N-terminal fragments of ribonuclease.
(4) It could perhaps be used in natural gas stations, where a synthetic gas is first produced by reacting the methane with steam to produce carbon dioxide and hydrogen.
(5) It is suggested that acetylene reduction assays may not be accurately applied to samples containing methane oxidizing bacteria.
(6) Certain methane- and methanol-oxidizing bacteria were grouped on the basis of serological cross-reacting enzyme specificities.
(7) The growth yield was 5.8 mg of cells (dry weight) per mmol of methane and was not dependent on the kind of methyl compound used as substrate.
(8) Various inhibitors that affected methane formation (e.g.
(9) The new methane rules – which will be formally unveiled on Wednesday - are the last big chance for Obama to fight climate change.
(10) Completely demineralized root powder was subjected to solutions of varying pH and ionic strength: (a) 0.1 M acetic acid, pH 4.0, (b) 0.1 M acetic acid + 0.15 M KCl, pH 4.0, (c) 0.1 M Hepes, pH 7.0 or to (d) 0.1 M Hepes + 0.15 M KCl, pH 7.0 at 37 degrees C. The surfaces of intact root specimens were exposed to 0.1 M acetic acid, pH 4.0 (which resulted in erosive lesions) or to 0.1 M lactic acid, 0.2 mM methane hydroxy diphosphonate, pH 5.0 (which produced subsurface lesions) at 37 degrees C. After incubation, the extracts were analysed for soluble collagen and the insoluble matrices were treated with trypsin at 15 degrees C to determine the denatured collagen.
(11) Particularly an automatic apparatus for monitoring total organic substances less methane, and one, employing specific detection and selective columns for the automatic and continuous determination of light sulfur compounds, are described.
(12) The ratio of methane (CH4) to CO2 in the abomasum gas was higher than that in the rumen.
(13) Hydrogen and methane are products of colonic bacterial metabolism.
(14) Other sources were monosodium methylarsenate (4 cases), dodecyl ammonium methane arsonate (5 cases), and other compounds (12 cases).
(15) The gas produced contained between 56 and 59% of methane.
(16) The present results reveal aspects of how both protein B and substrate can regulate electron transfer into and out of the hydroxylase component of methane monooxygenase.
(17) Using a complex, but soluble supplement (whey powder) it is shown that reproducible incremental measurements can be made and that the supplement used gives increases in production of characteristic end-products only (carbon dioxide, methane, acetic and butyric acids).
(18) Nickel did not alter methane production, carcass characteristics or ruminal volatile fatty acid proportions.
(19) Barack Obama has defied a Republican Congress to move ahead on his climate agenda on Wednesday, cracking down on methane emissions from America’s oil and natural gas boom.
(20) Twenty-six Acinetobacter calcoaceticus proline auxotrophs were isolated after ethyl methane sulfonate mutagenesis.