(n.) The act of resounding; the quality or state of being resonant.
(n.) A prolongation or increase of any sound, either by reflection, as in a cavern or apartment the walls of which are not distant enough to return a distinct echo, or by the production of vibrations in other bodies, as a sounding-board, or the bodies of musical instruments.
Example Sentences:
(1) By presenting the case history of a man who successively developed facial and trigeminal neural dysfunction after Mohs chemosurgery of a PCSCC, this paper documents histologically the occurrence of such neural invasion, and illustrates the utility of gadolinium-enhanced magnetic resonance scanning in patient management.
(2) The tumors were identified by magnetic resonance (MR) imaging.
(3) Twenty patients with non-small cell bronchogenic carcinoma were prospectively studied for intrathoracic lymphadenopathy using computed tomography (CT) and magnetic resonance imaging (MRI).
(4) Electron spin resonance studies indicate the formation of two vanadyl complexes that are 1:1 in vanadyl and deferoxamine, but have two or three bound hydroxamate groups.
(5) The role of magnetic resonance imaging is also discussed, as is the pathophysiology, management, and prognosis in the elderly patient.
(6) The resonance Raman spectra of oxy and deoxy cobalt-substituted hemoglobin (CoHb) are reported.
(7) In the same buffer a resonance marked L by Russu et al.
(8) An innovative magnetic resonance imaging technique was applied to the measurement of blood flow in the abdominal aorta.
(9) Sequelae of chemo- and radiotherapy were only depicted by magnetic resonance imaging.
(10) The present results using approximately 12% hemoglobin concentration in 0.1 M Bistris buffer at pD 7 and 27 degrees C with and without organic phosphate show that there is no significant line broadening on oxygenation (from 0 to 50% saturation) to affect the determination of the intensities or areas of these resonances.
(11) The linewidths of the methionine Cepsilon resonances are narrowed by increasing temperature according to an Arrhenius energy of activation of nearly 3 kcal.
(12) Magnetic resonance imaging of the spinal cord clearly demonstrated the entire lesion.
(13) Right ventricular volumes were determined in 12 patients with different levels of right and left ventricular function by magnetic resonance imaging (MRI) using an ECG gated multisection technique in planes perpendicular to the diastolic position of the interventricular septum.
(14) In April 1986, magnetic resonance imaging (MRI) of the thorax and shoulder girdle was presented to the 99th Annual Meeting of the American Association of Anatomists.
(15) In addition, a 31P nuclear magnetic resonance (NMR) technique was applied to investigate the in vivo energy metabolism of the graft.
(16) Line broadening detected in several of the high-field nuclear magnetic resonance spectra was attributed to cis-trans isomerization.
(17) The correlation of posterior intervertebral (facet) joint tropism (asymmetry), degenerative facet disease, and intervertebral disc disease was reviewed in a retrospective study of magnetic resonance images of the lumbar spine from 100 patients with complaints of low back pain and sciatica.
(18) Some additional amino proton resonances have also been assigned.
(19) The basic principle of the resonant tool, its adaptation for surgery, the experimental results of its use in animals, and clinical experience are reported.
(20) In this critical review of human in vivo nuclear magnetic resonance (NMR) spectroscopy, the questions of which chemical species can be detected and with what sensitivity, their biochemical significance, and their potential clinical value are addressed.
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.