(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.
Reduction
Definition:
(n.) The act of reducing, or state of being reduced; conversion to a given state or condition; diminution; conquest; as, the reduction of a body to powder; the reduction of things to order; the reduction of the expenses of government; the reduction of a rebellious province.
(n.) The act or process of reducing. See Reduce, v. t., 6. and To reduce an equation, To reduce an expression, under Reduce, v. t.
(v. t.) The correction of observations for known errors of instruments, etc.
(v. t.) The preparation of the facts and measurements of observations in order to deduce a general result.
(v. t.) The process of making a copy of something, as a figure, design, or draught, on a smaller scale, preserving the proper proportions.
(v. t.) The bringing of a syllogism in one of the so-called imperfect modes into a mode in the first figure.
(v. t.) The act, process, or result of reducing; as, the reduction of iron from its ores; the reduction of aldehyde from alcohol.
(v. t.) The operation of restoring a dislocated or fractured part to its former place.
Example Sentences:
(1) Direct fetal digitalization led to a reduction in umbilical artery resistance, a decline in the abdominal circumference from 20.3 to 17.8 cm, and resolution of the ascites within 72 h. Despite this dramatic response to therapy, fetal death occurred on day 5 of treatment.
(2) Use of the improved operative technique contributed to reduction in number of complications.
(3) Following central retinal artery ligation, infarction of the retinal ganglion cells was reflected by a 97 per cent reduction in the radioactively labeled protein within the optic nerve.
(4) It is concluded that amlodipine reduces myocardial ischemic injury by mechanism(s) that may involve a reduction in myocardial oxygen demand as well as by positively influencing transmembrane Ca2+ fluxes during ischemia and reperfusion.
(5) By 1978, the reduction in incidence of measles will exceed 90%.
(6) Osteoporosis is characterized by a reduction in bone density.
(7) At pH 7.0, reduction is complete after 6 to 10 h. These results together with an earlier study concerning the positions of the two most readily reduced bonds (Cornell J.S., and Pierce, J.G.
(8) A survey carried out two and three years after the launch of the official campaign also showed a reduction in the prevalence of rickets in children taking low dose supplements equivalent to about 2.5 micrograms (100 IU) vitamin D daily.
(9) The role of O2 free radicals in the reduction of sarcolemmal Na+-K+-ATPase, which occurs during reperfusion of ischemic heart, was examined in isolated guinea pig heart using exogenous scavengers of O2 radicals and an inhibitor of xanthine oxidase.
(10) Maximal covalent binding of [4,5-14C]ronidazole to DNA also required four-electron reduction, consistent with previous studies of the covalent binding of this agent to immobilized sulfhydryl groups [Kedderis et al.
(11) Optimum rates of acetylene reduction in short-term assays occurred at 20% O2 (0.2 atm (1 atm = 101.325 kPa] in the gas phase.
(12) Meanwhile, reductions in tax allowances on dividends for company shareholders from £5,000 down to £2,000 represent another dent to the incomes of many business owners.
(13) Polyribosomes isolated from the livers of rats sacrificed 6 h after treatment with actinomycin D showed a 42% reduction in their capacity to bind anti-RSA Fab'.
(14) In view of reports of the reduction of telomeric repeats in human malignant tumors, we measured the lengths of telomeric repeats in 55 primary neuroblastomas.
(15) Anatomic and roentgenographic criteria used for the assessment of reduction in ankle fractures are highlighted in this review of ankle trauma.
(16) By increasing luminal air pressure from 10 to 20 cm H2O a significant reduction in GBF was observed.
(17) The reduction rates of peripheral leukocytes, lung Schiff bases and lung water content were not identical in rats depleted from leukocyte after inhalation injury.
(18) The results show that in TMO-treated animals the time to the onset of convulsions, the time to the onset of NADH oxidation-reduction cycles, and the survival time were significantly longer than in the control group.
(19) Since the first is balked by the obstacle of deficit reduction, emphasis has turned to the second.
(20) The analysis of total seizure days showed a significant reduction during LTG treatment (p less than 0.002).