(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.
Phenylene
Definition:
(n.) A hypothetic radical (C6H4) occurring in certain derivatives of benzene; as, phenylene diamine.
Example Sentences:
(1) Efficacy of polyvinyl chloride collars containing temephos [0,0'-(thiodi-4,1-phenylene) 0,0,0',0'-tetramethyl bis-(phosphorothioate)] was elevaluated in dogs and cats against the cat flea (Ctenocephalides felis).
(2) The PCAH's identified in SRF-carbon black were: anthracene, phenanthrene, fluoranthene, pyrene, benzo(mno)fluoranthene, chrysene, 1,2-benzanthracene, 9,10-dimethyl-1,2-benzanthracene, 1,2-benzopyrene, 3,4-benzopyrene, perylene, o-phenylene pyrene 1,2-benzoperylene, anthanthrene, and coronene.
(3) Inhibition of MDA production to below control levels using the antioxidant N,N'-diphenyl-phenylene diamine (DPPD) however, had no inhibitory effect on cocaine-induced cytotoxicity in either mouse or rat cells.
(4) Platelet function studies, both in vitro and in vivo of dl-4,5,6-trinor-3,7-inter-m-phenylene-3-oxa-PGE1, methyl ester (VIII) are presented.
(5) The retention of radioactivity in the heart was also significantly prolonged when the p-phenylene group was in this position.
(6) New 1,4-diarylimidazole and 1,4-pyrrolimidazol-phenylene derivatives were prepared in attempt to deepen S.A.R.
(7) The activity of diamfenetide (N,N'-[oxybis(2,1-ethan diyloxy-4,1-phenylene)] bis acetamide) was studied in lambs experimentally inoculated with Fasciola hepatica.
(8) Acute effects of 200 mg of orally given 4-[2-(methylamino)ethyl]-o-phenylene diisobutyrate hydrochloride (ibopamine hydrochloride) which is a new diisobutyric ester of N-methyldopamine, on hemodynamics and metabolism were evaluated in 11 patients with severe heart failure (New York Heart Association class IV).
(9) Moreover, it is supposed that MDI may give rise to cross-sensitization to p-phenylene diamine and chemically related compounds.
(10) Muscle fibres in transverse "semithin" sections of osmium-fixed and plastic embedded muscle tissue stained with p-phenylene-diamine has been classified into three types (M, INT and H) and correlated to the same fibres in neighboring sequential preincubated myofibrillar ATP-ase sections.
(11) Several N,N'-(p-phenylene)dioxamic acids were synthesized also in the same manner starting with the requisite p-phenylenediamines.
(12) A close correlation, but no equality was found between the fibre types classified according to the ATP-ase and the p-phenylene-diamine methods.
(13) 2 was conducted to determine the effects of varying the length of the ortho-phenylene-diamine (OPD) incubation time upon assay results.
(14) In an alternative, but less satisfactory synthesis of 10, the compound (5-nitro-1, 3-phenylene) biscarbamic acid diphenyl ester (11), or the corresponding diethyl ester 12, was converted by ammonolysis to 13.
(15) Dogs and cats were treated with 2% temephos [0,0'-(thiodi-p-phenylene) 0,0',0'-tetramethyl bis (phosphorothioate)] powder to evaluate its insecticidal activity against the cat flea (Ctenocephalides felis).
(16) This addition may result in the saturation of the bridgehead double bond, thus allowing the two triple bonds to approach each other, causing cyclization of the diyn-ene to form a phenylene diradical.
(17) The peak heart uptake and the loss of radioactivity from the myocardium of fasted Sprague-Dawley rats depended on the alkyl-chain length and p-phenylene position.
(18) The consequences of incorporating variable-length flexible and rigid tethers [poly(methylene), Z and E ethylene, m- and p-phenylene] between the two netropsin-like moieties on the DNA binding properties were assessed by DNase I footprinting.
(19) The analyzing column is packed with porous polymer beads of 2,6-diphenyl-1,4-phenylene oxide.
(20) Surprisingly it turned out that the domain structure of S1 with ADP trapped by p-phenylene-N, N'-dimaleimide (pPDM) thiol cross-linking almost does not differ from that of the nucleotide-free S1.