(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.
Proton
Definition:
Example Sentences:
(1) Apparently, the irradiation with visible light of a low intensity creates an additional proton gradient and thus stimulates a new replication and division cycle in the population of cells whose membranes do not have delta pH necessary for the initiation of these processes.
(2) Plasma membranes were isolated from rat kidney and their transport properties for sodium, calcium, protons, phosphate, glucose, lactate, and phenylalanine were investigated.
(3) Hydrogen isotope effects on these mutants indicate that MotA catalyzes proton transfer.
(4) It was concluded that the detachment of the oxaloyl residue from oxaloacetate and its replacement by a proton proceed with inversion of configuration at the methylene group which becomes methyl during the hydrolysis.
(5) There was also a significant increase in the mitochondrial proton conductance pathway of brown adipose tissue, assessed from the binding of guanosine diphosphate (GDP) to mitochondria isolated from the interscapular (89% above control) and perirenal and para-aortic depots (130%).
(6) We propose that, for a GC base pair in B conformation, there are two amino proton exchangeable states--a cytosine amino proton exchangeable state and a guanine amino proton exchangeable state; both require the disruption of only the corresponding interbase H bond.
(7) The rhodamine 123-induced growth inhibition was partially reversed by treating the dye-pre-exposed infected erythrocytes with the proton ionophore carbonyl-cyanide m-chlorophenylhydrazone, which dissipates transmembrane proton gradients.
(8) The detergent lauryl maltoside abolishes respiratory control and proton ejection by cytochrome c oxidase-containing proteoliposomes over a narrow concentration range.
(9) These data are discussed in relationship to the chemical mechanism of GSSG reduction and the identity of the proton-transfer step whose rate is sensitive to solvent isotopic composition.
(10) The chromophore of octopus rhodopsin is 11-cis retinal, linked via a protonated Schiff base to the protein backbone.
(11) Some additional amino proton resonances have also been assigned.
(12) Binding to HSA occurs primarily with the imidazolidine and thiazolidine groups of levamisole as it has been demonstrated by selective changes in the relaxation times and the chemical shifts of the protons attached to the carbon atoms.
(13) Diffusional anisotropy of water protons, induced by nonrandom, directional barriers which hinder or retard water motion, is measurable by MRI.
(14) The present studies examined the effect of cytosolic protons on electrotonic spread and conduction velocity in cardiac Purkinje fibers.
(15) The Pr(III)-induced shifts for several resolved nonexchangeable backbone proton resonances were compared with calculated shifts using the known x-ray structure.
(16) The present analysis concentrates on the utilization of low-energy proton accelerators of several hundred kilovolts for particle-induced X-ray emission microanalysis.
(17) The amount of protons released is in excess with respect to the amount of ubiquinol oxidized.
(18) The ATPase inhibitor dicyclohexylcarbodiimide, which collapsed the chemical and electrical components of the proton motive force, caused rapid cell swelling in the presence of glucose (and high intracellular ATP levels).
(19) In a direct test of the hypothesis that the M2 coat protein of influenza A can function as a proton translocator, we incorporated a synthetic peptide containing its putative transmembrane domain into voltage-clamped planar lipid bilayers.
(20) The pH dependence of this spectral change gave a sigmoidal curve fitted well to a theoretical curve of a cooperative release of two protons with a pK value of 7.5, indicating the existence of the acidic and alkaline forms of the ferrous CO enzyme.