(n.) A gaseous compound of hydrogen and nitrogen, NH3, with a pungent smell and taste: -- often called volatile alkali, and spirits of hartshorn.
Example Sentences:
(1) This method provided myocardial perfusion images of high quality which were well correlated with N-13 ammonia images.
(2) Studies were performed to characterize the determinants of proximal tubule ammonia entry (and retention) in vivo.
(3) Confirmation of the striking correlation between increased urinary ammonia and lowered neonatal ponderal index may afford a simple test for the identification of nutrient-related growth retardation.
(4) However, almost all of the numerous compounds found to inhibit ammonia oxidizers also inhibit methanotrophs, and most of the inhibitors act upon the monooxygenases.
(5) An otherwise progressive rise in blood ammonia concentration was halted in the treatment group.
(6) The high rate of H pylori ammonia production in uraemic patients should accentuate any ammonia induced effects.
(7) The determination of ammonia in plasma, using glutamate dehydrogenase, is complicated by non-specific oxidation of the coenzyme, promoted by components of the sample matrix.
(8) The methanol-ammonia (20:1) and chloroform-methanol-ammonia (2:2:1) systems, used with silica-gel plates, are the most promising for rapid preliminary screening of tuna fish extracts for histamine.
(9) The effect of ammonia is partially reversed by nitrate.
(10) The addition of glutamine or ammonia increased glycine incorporation of control cultures, but failed to do so in treated cultures.
(11) Plasma dextrose and bicarbonate declined in concentration while potassium, lactate, LDH, ammonia, and hemoglobin rose with storage.
(12) The changes were proportional to the concentration and duration of ammonia treatment.
(13) The Km for ammonia of carbamyl phosphate synthetase was determined by preincubating isolated liver cells for 30 min in the absence of ammonia and bicarbonate and in the presence of ornithine, chloroquine, which blocks lysosomal proteolysis, and aminoxy acetic acid, which inhibits transaminases.
(14) The highest predictive values for the exclusion of TiC are shown by inconspicuous concentration capacity accompanied by normal ammonia excretion, total acid excretion, water diuresis, free water clearance or urine dilution capacity.
(15) All dogs were evaluated at the beginning of the study by complete physical examination; total and differential WBC counts; serum biochemical analysis (alanine transaminase and alkaline phosphatase activities and bilirubin and albumin concentrations); sulfobromophthalein excretion, ammonia tolerance, and glucagon response testing; portal and intraparenchymal pressure determinations; operative mesenteric portography; and histologic assessment of hepatic biopsy specimens.
(16) The significant differences (p=0.001) are found by lysine, ammonia, histidine, arginine, threonine, glutaminic acid, and phenyl alanine.
(17) Formation of anthranilate will proceed in the presence of partially pure subunit I provided ammonia is available in place of glutamine.
(18) Net synthesis of microbial N (Nn) was calculated from ammonia-N incorporation.
(19) Attachment of sufficient quantities of PEG to phenylalanine ammonia-lyase substantially reduces immunological recognition and clearance of the conjugated enzyme in mice.
(20) No direct relationship exists between glutamate dehydrogenase (NADP+) and glutamate-ammonia ligase in P. denitrificans, while the glutamate synthase (NADPH) activity changes in parallel with that of the latter enzyme.
Hydride
Definition:
(n.) A compound of the binary type, in which hydrogen is united with some other element.
Example Sentences:
(1) The corresponding hydrides, mono-n-butyltin hydride, di-n-butyltin hydride, tri-n-butyltin hydride, monophenyltin hydride, diphenyltin hydride triphenyltin hydride, are detected by electron-capture gas chromatography after clean-up by silica gel column chromatography.
(2) The latter compounds were reduced with lithium aluminium hydride to the respective amines (II a-c) and then N-alkylated by reaction with 2-propynyl-, 2-butynyl- or 2,3-butadienyl bromides to the corresponding amines (III a-j).
(3) The mechanism of hydrogen activation was shown to be heterolytic cleavage to an enzyme hydride and a proton.
(4) The lithium aluminum hydride reduction product of the 24R-acid (Vb) was identical with the naturally occurring 5 beta-ranol, hence 5 beta-ranol has the 24R configuration.
(5) An evaluation of the possible role of flavins (as a hydride carrier between NADPH and the steroid) has shown that progesterone 5 alpha-reduction is inhibited by high levels of flavins and flavin analogs.
(6) The higher the rate of hydride transfer at pH 7.65, the higher the pH of the cross-over point.
(7) Because we have been unable to detect trans coordination of 2-mercaptoethanol, we favor a mechanism that involves a hydride attack on the Co-methylene carbon of (carboxymethyl)cobalamin rather than a trans attack of the thiol on the cobalt atom.
(8) Only O-benzoylation occurred on reaction with benzoic an hydride.
(9) 40- and 60-S ribosomal subunits and 80-S ribosomes from rat liver were highly labelled by reductive methylation using formaldehyde and sodium boro-[3H] hydride, under conditions which did not decrease their activity in poly-U-directed polyphenylalanine synthesis.
(10) A new rapid high yield synthesis of radiolabeled N'-(4-11C-methyl)imipramine has been developed using a reductive-carboxylation approach, in which 11CO2 is reacted with either N'-trimethylsilyldesimipramine or N'-lithium derivative of desimipramine, followed by lithium aluminum hydride reduction, to give no carrier added or carrier added 11C-labeled imipramine respectively.
(11) Reduction of this mixture 1 with sodium aluminum bis-(methoxyethoxy)hydride furnished the 11 beta, 18, 21-triol 2a.
(12) The two mechanisms have been assessed in terms of the calculated absolute and relative pKas of the protonated species taking into account experimental information regarding possible stabilization of these forms in the enzyme active site and also the effectiveness of the various protonations in assisting the hydride ion transfer step.
(13) A radioactive label was introduced by using sodium boro[3H]hydride to reduce the initially formed Schiff's base.
(14) After deoxygenation of 2'-O-[[(4-methylphenyl)oxy]thiocarbonyl] compounds 20A-E with tributyltin hydride the 2,3'-anhydro bridge of the 2'-deoxynucleosides 21A-E was opened with LiN3 to produce the protected 3'-azido-2,3'-dideoxynucleoside derivatives 22A-G. Saponification with NaOCH3 gave 1-(3'-azido-2',3',5'-trideoxy-beta-D-allofuranosyl)thymine (2; homo-AZT), the 5'-C-(hydroxymethyl) derivatives of AZT 1-(3'-azido-2',3'- dideoxy-beta-D-allofuranosyl)thymine (3) and 1-(3'-azido-2',3'-dideoxy-alpha-L-talofuranosyl)thymine (4), and the 5'-C-methyl derivatives of AZT 1-(3'-azido-2',3',6'-trideoxy-beta-D-allofuranosyl)thymine (5) and 1-(3'-azido-2',3',6'-trideoxy-alpha-L-talofuranosyl)thymine (6).
(15) While further improvements might lead to potential enhancement of sensitivity and precision of as much as an order of magnitude, the present performance of the hydride system was satisfactory in relation to the requirements of isotopic analysis for metabolic investigations employing 74Se as the in vivo stable isotope tracer.
(16) These models, in turn, have suggested detailed mechanisms for the various chemical steps of the reaction: a ring opening catalysed by an activated histidine, a hydride-shift isomerization, and a ring closure which may be facilitated by a polarised water molecule.
(17) The disulfide form but not the sulfhydryl form of a boron hydride compound was found to be cataractogenic.
(18) Proper molecular orientation is required for hydride transfer (Dalziel and Dickinson, 1967).
(19) An alkylation technique using methyl iodide and sodium hydride in dimethyl sulfoxide has been evaluated for 3 carbamate and 7 urea herbicides in 9 foods.
(20) To determine the effectiveness of the selenium reduction and the completeness of the selenium hydride formation a parallel selenium determination was carried out by means of ICP-AES and FI-HAAS analysis.