(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.
Nitrogen
Definition:
(n.) A colorless nonmetallic element, tasteless and odorless, comprising four fifths of the atmosphere by volume. It is chemically very inert in the free state, and as such is incapable of supporting life (hence the name azote still used by French chemists); but it forms many important compounds, as ammonia, nitric acid, the cyanides, etc, and is a constituent of all organized living tissues, animal or vegetable. Symbol N. Atomic weight 14. It was formerly regarded as a permanent noncondensible gas, but was liquefied in 1877 by Cailletet of Paris, and Pictet of Geneva.
Example Sentences:
(1) These results are discussed in relation to the possible existence of enzyme-bound intermediates of nitrogen fixation.
(2) The measurement of the intestinal metabolism of the nitrogen moiety of glutamic acid has been investigated by oral ingestion of l-[15N]glutamic acid and sampling of arterialized blood.
(3) The induction of cells with two Y chromosomes by nitrogen mustard (NM) was examined.
(4) The disappearance of the herbicide, Avadex (40% diallate), from five agricultural soils (differing in either pH, carbon content, or nitrogen content), incubated under sterile and non-sterile conditions, was followed for a period of 20 weeks.
(5) Suspensions of isolated insect flight muscle thick filaments were embedded in layers of vitreous ice and visualized in the electron microscope under liquid nitrogen conditions.
(6) Airway closure (CV), functional residual capacity (FRC) and the distribution of inspired gas (nitrogen washout delay percentage, NWOD %) and arterial oxygen tension (PaO2) was measured by standard electrodes in eight extremely obese patients before and after weight loss (mean weights 142 and 94 kg, respectively) following intestinal shunt operation.
(7) Formula fed infants retained more nitrogen and gained weight faster.
(8) Triglyceride (Trigly) in female dogs, glutamic-pyruvic transaminase (GPT) and urea nitrogen (Urea-N) in male dogs tended to increase.
(9) Nitrogen retention was curvilinear in relation to metabolic live weight (kg0.75) in both series.
(10) Corynebacterium parvum-treated mice produce large amounts of circulating nitrogen oxides and develop a severe liver injury in response to lipopolysaccharide (LPS).
(11) Eight men and eight women each performed peak oxygen intake tests on a cycle ergometer breathing ambient air and a mixture of 12% oxygen in nitrogen (equivalent to an altitude of 4400 m) in the two experiments.
(12) From this, it was suggested that a negligible amount of oestradiol was released from these compounds and that the oestradiol moiety was useful as a carrier for the nitrogen mustard moiety.
(13) The intravenous administration of ovine placental lactogen to pregnant and non-pregnant sheep produced significant acute decreases in plasma free fatty acid, glucose and amino nitrogen concentrations.
(14) In contrast, nitrogen incubation did not alter the basal levels of TBA reactants except for a small rise associated with VE deficiency.
(15) MCT TPN was found to have some disadvantages, especially with regard to nitrogen balance and plasma albumin levels.
(16) Nitrogen mustard (N2M) treatment of rabbits induced neutropenia, and, in ligated ileal loops, it inhibited fluid secretion induced by salmonella or by cholera toxin (CT).
(17) 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.
(18) The raw data are obtained by capillary gas chromatography using a nitrogen-phosphorus detector.
(19) Total protein, RNA, DNA, nitrogen, free amino acids and water content were determined in both lymphatic organs.
(20) This is the first evidence supporting carbon-nitrogen bond formation as the initial site of interaction between the two substrate molecules.