(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.
Monobasic
Definition:
(a.) Capable of being neutralized by a univalent base or basic radical; having but one acid hydrogen atom to be replaced; -- said of acids; as, acetic, nitric, and hydrochloric acids are monobasic.
Example Sentences:
(1) It is concluded that in this cell type (i) somatostatin-14 is exclusively generated by dibasic cleavage at the Arg-2-Lys-1 site of the intact precursor with concomitant production of prosomatostatin[1-76], and (ii) no direct interactions between the monobasic and dibasic processing domains occur.
(2) At 95 degrees C in the denatured form cytosine residues titrated as a simple monobasic acid of pK3.9 compared with pK approximately 2.5 for the native form at 25 degrees C. 2.
(3) These results demonstrate that AtT-20 cells efficiently and accurately process prodynorphin at both dibasic sites and monobasic cleavage sites, indicating that the AtT-20 cells contain enzymes capable of cleaving the precursor not only at dibasic residues but also at monobasic residues.
(4) Apurinic sites were introduced to dGpdG, dGpdT, dTpdG and pdGpdG by HCl hydrolysis and the cleavage of the phosphodiester bond was measured in the monobase dinucleotides by HPLC.
(5) Additional mitomycin admixtures were reconstituted with a buffer solution containing monobasic and dibasic sodium phosphate; these were diluted with 5% dextrose injection only.
(6) Comparison of amino acids around the monobasic cleavage sites suggests that these cleavages follow certain sequence motifs and can be described as the rules that govern monobasic cleavages: (i) a basic amino acid is present at either 3, 5, or 7 amino acids N-terminal to the cleavage site, (ii) hydrophobic aliphatic amino acids (leucine, isoleucine, valine, or methionine) are never present in the position C-terminal to the monobasic amino acid at the cleavage site, (iii) a cysteine is never present in the vicinity of the cleavage site, and (iv) an aromatic amino acid is never present at the position N-terminal to the monobasic amino acid at the cleavage site.
(7) From these results it can be concluded that both the "dibasic" cleavage between vasopressin and MSEL-neurophysin and the "monobasic" cleavage between MSEL-neurophysin and copeptin occur within the granule compartment.
(8) In fact, a monobasic cleavage requires two basic residues and a domain containing nonpolar amino acids such as alanine or leucine, or both.
(9) The basic extract was neutralized and analyzed on a phenyl column eluting with acetonitrile:10 mM potassium phosphate (30:70; monobasic, pH 5.6).
(10) The method is based on derivatization with the chiral reagent 2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl isothiocyanate (GITC), and resolution of the resulting diastereomeric thioureas by reversed-phase HPLC using methanol-aqueous monobasic ammonium phosphate mixture as the mobile phase.
(11) dibasic and monobasic specific forms, might explain the tissue-specific processing of precursors like the pro-opiomelanocortin and the CKK and somatostatin precursor.
(12) The most abundant of these were two 39 aa forms that resulted from the monobasic endoproteolytic cleavage of proHNP-1 and proHNP-3.
(13) The monobasic macrolide erythromycin on the other hand was less affected by the SC9252 mutation, less effectively antagonized by Mg2+, and was a far less effective permeabilizer than dibasic azithromycin.
(14) In the flounder the same dibasic residue processing site is utilised but cleavage at different monobasic sites takes place (corresponding to Arg50 and Arg97 in anglerfish preprosomatostatin II).
(15) Accordingly, we evaluated the buffering capacity of seven synthetic organic buffers and monobasic potassium phosphate, both singly and in pairs, over the pH range 7.4 to 6.0.
(16) It is concluded that the processing site in the intermediate form of the pancreatic eicosapeptide is an example of a proline-directed monobasic cleavage site that has been conserved during evolution.
(17) A liquid medium, designated as Kabatiella zeae medium (KZM), containing 10.0 g of carboxymethylcellulose, 5.0 g of maltose, 1.5 g of peptone, 1.0 g of monobasic potassium phosphate, 1 L of distilled water, is described.
(18) Both peptides are synthesized as larger precursors containing paired basic and monobasic amino acids at their processing sites, which, upon cleavage, generate either SRIF-14 or -28, respectively.
(19) The monobasic processing could also be distinguished from the dibasic cleavage mechanism as, in time, the cells gradually lost the ability to cleave at the monobasic site while the dibasic processing was unaffected.
(20) It was found that the sulfonamide ligands act as monobasic bidentate ON donors.