(n.) A gaseous element found in the atmospheres of the sun and earth and in some rare minerals.
Example Sentences:
(1) Irradiation of the skin overlying the median nerve at the wrist in humans with a low power (1 mW; 632.5 nm) helium-neon laser produced a somatosensory evoked potential obtained at Erb's point.
(2) To determine if computed tomography (CT) can accurately measure lung volume, we compared lung gas volume measured by helium dilution with the equivalent volume calculated from CT total lung volume and density in 13 supine dogs.
(3) The biological effects of the helium-neon (He-Ne) laser on skin and oral mucosa were examined for the first time electron microscopically.
(4) For the estimation and correction of errors in the measurement of the respiratory flow with viscosity-affected respiratory flow receptors the viscosity of natural respiratory gases (N2, O2, CO2, H2O) and of the ternary system helium-oxygen-nitrogen, which is of importance in pulmonary function diagnosis, was determined.
(5) It uses neutron irradiation and subsequent measurements of helium 3 and helium 4 in a static mass spectrometer.
(6) The effects of helium and argon, inert gases, on oxygen consumption have been studied on liver tissue of white rats who were delivered different fatty products plus to basic food).
(7) Experiments were performed in a cylinder full of beads open at one end and closed at the other in which a mixture of oxygen with helium or argon or sulphur hexafluoride could diffuse with ambient air through the open end.
(8) We hypothesized that the use of dilutant gases, as helium (He) or hydrogen (H2), having low density but high specific heat compared to nitrogen, could change the TE vs TI regression.
(9) In eight of the 13 patients studied the baseline ratio of expiratory flow at 50% vital capacity (VC) breathing helium-oxygen (V50He) to V50air was over 1.20 and they were called responders; the remaining five patients were called non-responders.
(10) Physiologic studies included maximal expiratory flow volume curves with air and helium-oxygen mixtures.
(11) 7, 14, 19 and 31 atmosphere absolute (ATA) with helium-oxygen or helium-nitrogen-oxygen have been performed at the Japan Marine Science and Technology Center.
(12) At the 50 per cent embryonic survival level, helium ion r.b.e.
(13) Similar exercise in 25.5 degrees C water, breathing helium tri-mix (gas density less than air), produced higher VE but lower VO2 when compared to air breathing.
(14) In a third group of subjects we compared helium flux blood flow (stripped skin) to laser doppler velocimetric (LDV) measurements (intact skin) at adjacent skin sites and found a nonlinear increase in the LDV skin blood flow compared to that determined by helium over the same temperature range.
(15) I was sitting in the room, reading all the negativity and death threats, and by now the helium balloons were half-full, hovering like jellyfish.
(16) After intravenous blood exposure to low-intensity radiation of Helium-Neon laser patients with haemorrhagic pancreatitis exhibited inhibition of the blood proteolytic activity; enhancement of free-radical oxidation, kallikrein-kinin system activity, blood oxygen transport, correction of endotoxic pancreatogenic syndrome.
(17) The effects of balloon rupture may be compounded by the use of helium as a driving gas to inflate the balloon.
(18) An atomic emission detector, consisting of a microwave-induced helium plasma and atomic emission spectrometer, has been used for the gas chromatographic analysis of pesticides.
(19) The modification effect of the anoxic radiosensitizer TAN on the mutagenesis in various Salmonella tester strains after gamma-ray and helium ion irradiation was studied.
(20) The clinical and laboratory findings were examined of 10 patients with seropositive rheumatoid arthritis (RA) treated with a first applied technique of intravenous irradiation of the circulating blood with helium-neon laser combined with external irradiation of the inflamed joints.
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.