() An unsymmetrical, divalent, hydrocarbon radical, C2H4 metameric with ethylene but written thus, CH3.CH to distinguish it from the symmetrical ethylene, CH2.CH2. Its compounds are derived from aldehyde. Formerly called also ethidene.
Example Sentences:
(1) These results indicate that an A-ring ethylidene-containing bilatriene is required for post-translational covalent attachment of bilin to apophytochrome and that apophytochrome may be the bilin C-S lyase which catalyzes bilin attachment.
(2) Two mutagens, 2-amino-1-methyl-5-propylideneimidazol-4-one (AMPI) and 2-amino-5-ethylidene-1-methylimidazol-4-one (AEMI) were isolated and characterized by UV absorption spectra, mass spectra, and 1H-NMR.
(3) The cytotoxic and cell kinetic effects of the epipodophyllotoxin 4,6-demethylepipodophyllotoxin-9-(4,6-O-ethylidene-beta-D-glucopyr anoside) (VP-16) in cultured mammalian cells are thought to relate to the induction of DNA damage, specifically DNA strand interruptions.
(4) Reference ranges for alpha-amylase in serum, spontaneously voided urine, and 24 h urine were determined, using 4,6-ethylidene-(G7)-1-4-nitrophenyl-(Gl)-alpha,D-maltoheptaoside as the substrate (EPS method), at 25, 30, and 37 degrees C. The measured values were evaluated with and without the use of a factor which converts the results of the alpha-amylase EPS method into values comparable to those obtained with the alpha-amylase PNP method (substrate: 4-nitrophenyl-alpha,D-maltoheptaoside); comparison with the established reference ranges of the PNP method was therefore possible.
(5) The effects of the calcium antagonist verapamil on the intracellular disposition of 4'-demethylepipodophyllotoxin-9-(4,6-O-ethylidene-beta-D-glucopyra noside) (etoposide) (VP-16) as well as on subsequent DNA damage and cytotoxicity were studied in L1210 cells in vitro.
(6) Synthesis of the regular branched polysaccharide [-6(Gal beta 1-4)GlcNAc beta 1-3Gal beta 1-4Glc beta 1-]n structurally corresponding to capsular polysaccharide of Streptococcus pneumoniae type 14 involves blockwise synthesis of a tritylated 1,2-O-(1-cyano)ethylidene tetrasaccharide derivative from lactosamine and lactose precursors followed by stereospecific polycondensation of the tetrasaccharide monomer.
(7) The labelling was inhibited by 4,6-O-ethylidene-D-glucose.
(8) 4,6-O-Ethylidene-D-glucose inhibited wild-type transport with a Ki of approximately 12 mM, but this was increased to greater than 120 mM in the Gln282----Leu mutant.
(9) Drug uptake studies reveal equivalent equilibrium intracellular concentrations of [3H]9-(4,6-O-ethylidene-beta-D-glucopyranosyl)-4'-demethyepipodophyll otoxin in the resistant and parental cells.
(10) The effects of KW-3635 (sodium (E)-11-[2-(5,6-dimethyl-1-benzimidazolyl)- ethylidene]-6,11-dihydrodibenz[b,e]oxepine-2-carboxylate monohydrate, CAS 127166-41-0) on smooth muscle preparations were examined.
(11) The GC method allowed the quantitation of 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine, and major metabolite of methadone.
(12) Cells pre-incubated with 76 mM ethylidene glucose did not show an uphill transfer from 4 mM-[(14)C]glucose in the outside medium in contrast to cells pre-incubated in 76 mM glucose or in 76 mM 3-O-methyl glucose.5.
(13) Four malto-oligosaccharides (dp 2-5), each with a 4,6-O-ethylidene group on the glucosyl unit at the non-reducing terminus, were synthesised and used to prove that the maltose-binding protein (MBP) of E. coli is a closed-groove binder.
(14) Podophyllotoxin, 4'-demethylpodophyllotoxin and 4'-demethylepipodophyllotoxin excluding an ethylidene glucose group had more anti-HeLa, but much less anti-L1210 activity than etoposide.
(15) No crossreactivity was found with alpha 1-methadol, morphine, meperidine, dextropropoxyphene, 2-ethyl-5-methyl-3,3-diphenyl-l-pyrroline and 2-ethylidene-l, 5-dimethyl-3,3-diphenylpyrrolidene.
(16) The essential amino acid L-tryptophan (L-Trp) was found to be an effective inhibitor of the development of mutagenicity (Ames test) in liquid-reflux models known to produce identified IQ-type mutagens, such as 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) and 2-amino-3,7,8-trimethylimidazo[4,5-f]quinoxaline (7,8-DiMeIQx), and in reflux models recently developed in our laboratory that have been found to produce novel IQ-"like" mutagens (aminoimidazol-4-ones), which we have identified as 2-amino-1-methyl-5-propylideneimidazol-4-one (TCP-1), and 2-amino-5-ethylidene-1-methylimidazol-4-one (TCP-2 or ACP).
(17) Condensation of 6-azauridine with ethyl levulinate, followed by saponification or phosphorylation, leads to 2',3'-O-[1-(2-carboxyethyl)ethylidene]-6-azauridine and its 5'-monophosphate.
(18) Removal of the chloroacetyl groups from 12 beta, its alpha analogue 12 alpha, and 15 beta gave the 4-O-(2-benzyloxycarbonylamino-2-deoxy-4,6-O-ethylidene-alpha-(17 alpha) and -beta-D-glucopyranosyl)-4'-O-demethyl-epipodophyllotoxins (17 beta and 20 beta), respectively.
(19) The biosynthetic origin of the carbon skeleton of 3-ethylidene-L-azetidine-2-carboxylic acid (polyoximic acid) is described.
(20) The asymmetrical nature of sugar affinity for the hexose transfer system in human red cells has been demonstrated using purified 4,6-O-ethylidene-alpha-D-glucopyranose (ethylidene glucose) to inhibit the exchange of glucose, 3-O-methyl glucose and galactose.
Hydrogen
Definition:
(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.