(a.) Pertaining to, or containing, hydrogen and fluorine; fluohydric; as, hydrofluoric acid.
Example Sentences:
(1) A technique is described which the glass coverslip of a culture, flat embedded in epoxy resins can be removed easily using hydrofluoric acid.
(2) Especially in the case of Scotchprime treatment, hydrofluoric acid etching was remarkably effective on the increase in the bond strengths.
(3) We have reported the case of a man who was totally immersed in a 10% hydrofluoric acid solution.
(4) We present two fatal cases resulting from extensive exposure to hydrofluoric acid which produced acute systemic metabolic acidosis with profound hypocalcemia and hypomagnesemia.
(5) Dynamic studies showed that the combined action of phosphine and hydrofluoric acid damages the Krebs cycle reactions, dehydrogenization of isocitrate and synthesis of citrate in homogenized rat liver.
(6) With the exception of the excessive exposure to acidulated fluoride, ammonium bifluoride, or hydrofluoric acid, there is little risk of surface degradation of virtually all current dental ceramics.
(7) This system purportedly eliminates hydrofluoric acid-etching and silane pretreatment.
(8) Hydrolysis, treatment with aqueous hydrofluoric acid, and 1H and 13C nuclear magnetic resonance studies showed that the glycoprotein glycan is a high-molecular-weight polymer (approximate Mr, 15,000) of tetrasaccharide repeating units with the component sugars N-acetylgalactosamine (GalNAc), N-acetylmannosamine (ManNAc), and N-acetylbacillosamine (BacNAc; 2-N-acetyl-4-amino-2,4,6-trideoxy glucose) linked by monophosphate diesters.
(9) Hydrofluoric acid is used in a variety of industries and poses a considerable medical hazard.
(10) From SEM observation, hydrofluoric acid etching gave greater roughness to the porcelain surface, which resulted in greater mechanical interlocking of the resin.
(11) Hydrofluoric acid can thus be used to specifically cleave Rha-containing polysaccharides.
(12) If an ophthalmologist is the first to treat a patient with chemical exposure, the history of hydrofluoric acid exposure must be obtained, and the burn team and other medical specialists must be quickly consulted to avoid potentially fatal complications.
(13) Introduction of a halogen atom at C-2 of steroid 3-ketofluorohydrins, obtained from the corresponding 5alpha,6alpha-epoxides by trans-diaxial opening with hydrofluoric acid, prevents the 6beta-fluorine atom from undergoing rearrangement to the more stable 6alpha configuration when the 5-tert-hydroxyl is split off to yield to yield a conjugated double bond.
(14) The experimental variables included three porcelain surface preparations, as polished, etched with phosphoric acid, or etched with hydrofluoric acid and three kinds of commercially available silane coupling agents.
(15) Following hydrofluoric acid (HF) treatment, tau PHF proteins are heat- and acid-stable, soluble in 2-(N-morpholino)ethanesulfonic acid buffers and display the same molecular weight, pI, and immunochemical properties as normal tau s. Alkaline phosphatase treatment of dissociated PHF results in similar, although less extensive, electrophoretic changes and a reduction in PHF-1 immunoreactivity.
(16) In a previous report, observations were made on the apporopriate concentrations of hydrofluoric acid and durations of application in treating porcelain surfaces to improve the bonding strength at the porcelain-resin interface.
(17) The fluoride ion levels (geometric mean) in the urine and in the serum of the non-hydrofluoric-acid workers were determined to be 0.59 ppm and 12 ppb, respectively.
(18) Acidified sample (1l) with a known amount of 95Zr was evaporated to dryness, treated with hydrofluoric and nitric acids, and then with nitric and perchloric acids, and evaporated nearly to dryness.
(19) We have deglycosylated the enzyme gamma-glutamyl transpeptidase by treatment of the protein with anhydrous hydrofluoric acid at 0 degree C. After deglycosylation, the heavy and light subunits showed a molecular weight of 43 and 23 Kd respectively.
(20) A patient with hydrofluoric acid burns involving only 8% of his body surface area died from intractable cardiac arrhythmia secondary to the depletion of ionized calcium by fluoride ion.
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.