(n.) Equality of weight or force; an equipoise or a state of rest produced by the mutual counteraction of two or more forces.
(n.) A level position; a just poise or balance in respect to an object, so that it remains firm; equipoise; as, to preserve the equilibrium of the body.
(n.) A balancing of the mind between motives or reasons, with consequent indecision and doubt.
Example Sentences:
(1) In contrast with oligodendrocytes, [Cl-]i in astrocytes is significantly increased (from 20 to 40 mM) above the equilibrium distribution owing to the activity of an inward directed Cl- pump; this suggests a different mechanism of K+ uptake in these cells.
(2) Although the brain AP50 is prominently phosphorylated by an endogenous protein kinase in isolated coated vesicle preparations, the neuronal AP50 was not detectably phosphorylated in intact cells as assessed by two-dimensional non-equilibrium pH gradient gel electrophoresis of labeled cells dissolved directly in SDS-containing buffers.
(3) Fibroblasts from WHHL rabbits bound little, if any, human LDL, an apo B-containing lipoprotein, in 4 degrees C equilibrium binding experiments.
(4) Analysis of the product by equilibrium density centrifugation and processive hydrolysis with snake venom phosphodiesterase suggested that the noncomplementary nucleotides were present in phosphodiester linkage.
(5) It is shown that, by comparison of a reacting mixture at chemical equilibrium with a non-reacting but equally composed one, the sum of the mean concentrations of the reaction products can immediately be taken from optical absorption or from interferometric measurements.
(6) Equilibrium and kinetic studies of the interaction of gene 32 protein of T4 phage with single-stranded fd DNA were performed monitoring the changes in protein fluorescence.
(7) Equilibrium and kinetic aspects of the binding of several proteins to N-(3-carboxypropionyl)aminodecyl-Sepharose, an amphiphilic ampholytic adsorbent, were studied at 22 degrees C, pH 7.0, I 0.10--0.12.
(8) Ceftriaxone, a cephalosporin, is bound reversibly to defatted human serum albumin from adults, with a first stoichiometric binding constant of 60,000 M-1, as found by equilibrium dialysis at pH 7.4, 37 degrees.
(9) In addition, a redistribution of cellular controls of the host reaction to parasites may act as a complementary mechanism for establishment of the viable equilibrium between host and parasite.
(10) In addition, although aspirin does transfer the acetyl group to hemoglobin both in vitro and in vivo, in our experiments the reaction does not result in any alteration in the oxygen equilibrium of either intact erythrocytes or hemoglobin in solution.
(11) administration the time for distribution in the body amounted to 8 h. The extrapolated initial concentrations in the equilibrium to distribution amounted to 0.68% of the administered dose in the plasma volume, and the theoretical volume of distribution was 5 times the body volume.
(12) This conception of the city as an expression of both regal power and social order, guided by cosmological principles and the pursuit of yin-yang equilibrium, was unlike anything in the western tradition.
(13) A molecular weight of 51,500 was determined from sodium dodecyl sulfate polyacrylamide gel electrophoresis, while sedimentation equilibrium ultracentrifugation gave a value of 49,500.
(14) Due to the higher stability constant, of MgCDTA, as compared to MgEDTA, addition of CDTA to a medium containing free Mg2+ and MgEDTA will not only chelate the free Mg2+, but it will also shift the equilibrium from MgEDTA towards MgCDTA, i.e.
(15) At alkaline pH, the Schiff's base equilibrium can be continuously and specifically displaced by reduction in situ with sodium cyanohydridoborate, which on the other hand leaves intact the reacting aldehyde groups of oxidized tRNA.
(16) Scatchard analysis of equilibrium 125I-HA binding to permeabilized hepatocytes in suspension at 4 degrees C indicates a Kd = 1.8 x 10(-7) M and 1.3 x 10(6) molecules of HA (Mr approximately 30,000) bound per cell at saturation.
(17) If the PET measurement is commenced prior to arteriovenous equilibrium, significant errors occur in calculated CBV.
(18) Cells were labeled with [3H]AA for 3 h, followed by a 20-h equilibrium period, then exposed to 10(-8) M PTH for different time periods ranging from 2-60 min.
(19) The equilibrium binding constants for the binary complex formation of eIF-4E-eIF-4A, m7GpppG-eIF-4E, m7GpppG-eIF-4F, globin mRNA-eIF-4E, globin mRNA-eIF-4F, and globin mRNA-eIF-4A were measured by direct fluorescence titration experiments.
(20) To validate the repeated use of radionuclide equilibrium angiography for determining left ventricular (LV) ejection fraction (EF) and end-diastolic and end-systolic volumes (EDV and ESV), 25 patients were studied on an hourly basis an average of 9.1 days after acute myocardial infarction.
Tautomerism
Definition:
(n.) The condition, quality, or relation of metameric substances, or their respective derivatives, which are more or less interchangeable, according as one form or the other is the more stable. It is a special case of metamerism; thus, the lactam and the lactim compounds exhibit tautomerism.
Example Sentences:
(1) The coupled dienone-phenol re-arrangement and keto-enol tautomerism of this quinone methide produce the observed 3,4-dihydroxybenzaldehyde.
(2) On the other hand, results indicate that the protonation of formycin and its derivatives at the N1 atom leads to a change in their tautomeric preference from N7-H to N8-H.
(3) The inhibitor trapping system, however, prevents the inactivation of succinate dehydrogenase under the conditions when the rate of tautomeric oxaloacetate enol in equilibrium oxaloacetate ketone interconversion is high.
(4) In contrast, equilibria of ring chain tautomerism and covalent hydration of aldoses are almost completely insensitive to the polarity of their surroundings.
(5) The importance of both tautomerism and protonation reactions in the mechanism of action of adenosine deaminase is studied by means of a quantitative structure activity relationships strategy.
(6) The possibility that this product is an equilibrium mixture with the tautomeric 4-hydroxycyclophosphamide has not been as yet defintely ruled out.
(7) In addition to being a possible mechanism for alteration of hydrogen bonding in oxidized DNA, this type of interaction gives a better understanding into N7-N9 tautomerism of adenine.
(8) The product 3-fluorooxalacetate is thus released from phosphoenolpyruvate carboxykinase as the keto form and is reduced more rapidly by reduced nicotinamide adenine dinucleotide with malate dehydrogenase than by the occurrence of tautomerization.
(9) These results strongly suggest that the anomeric, epimeric, and tautomeric form of the sugar phosphate substrates favored by both enzymes is the beta-D-fructofuranose form.
(10) Tautomerization of DOPA quinone to dehydroDOPA may thus be a factor in the sclerotization of natural structures incorporating DOPA containing proteins.
(11) For the complex formed between [5,5-2H,5-13C]ALA and methyl methanethiosulfonate (MMTS) modified PBG synthase, which does not catalyze PBG formation but can form a Schiff base adduct, the chemical shift of 44.2 ppm (line width 92 Hz) identifies an imine structure as the predominant tautomeric form of the Schiff base.
(12) delta 5-3-Ketosteroid isomerase (EC 5.3.3.1) catalyzes the isomerization of delta 5-3-ketosteroids to delta 4-3-ketosteroids by a conservative tautomeric transfer of the 4 beta-proton to the 6 beta-position with Tyr-14 as a general acid and Asp-38 as a general base [Kuliopulos, A., Mildvan, A. S., Shortle, D., & Talalay, P. (1989) Biochemistry 28, 149-159].
(13) The results are consistent with evidence for the formation of the first tetrahydropterin intermediate by a tautomerization without any requirement for NADPH.
(14) Its function is probably to maintain the orientation and tautomeric state of the imidazole ring of histidine-159.
(15) This suggests that a stable AP:C base mispair via two hydrogen bonds can be formed with the imino tautomer of C. These results stress the importance of the imino form of C in AP-induced mutagenesis and support the 'trigger mechanism', in which formation of one hydrogen bond between AP and C is considered to stimulate the tautomeric shift of AP or C. The calculated relative stabilities of various base pairs and mispairs were in good agreement with experimental findings.
(16) Whereas O6-MeGua did not form hydrogen bonds with cytosine (via usual, wobble, or unusual tautomeric structures), it did form a 1:1 hydrogen-bonded complex with protonated cytosine.
(17) Amide-imide tautomerism enables a cleanup of the extract.
(18) Ultraviolet and infrared spectrophotometric techniques have been utilized to demonstrate that the monoanionic form of 2-thiouracil in aqueous medium consists of an equilibrium mixture of two tautomeric monoanions, one due to dissociation of the N1 proton, the other to dissociation of the N3 proton, in the approximate ratio 1:1.
(19) Combined use of mass spectroscopy and 1H- and 13C-NMR spectroscopy established that it is the 4,8-anhydro derivative of N-acetylneuraminic acid and that in solutions it exists in two tautomeric forms.
(20) As a result of a concerted proton (tautomeric) shift in the linked residues of the hydrogen-bond chain, which includes the bound molecule, a charge separation occurs.