(n.) A very small libratory motion of the earth's axis, by which its inclination to the plane of the ecliptic is constantly varying by a small amount.
(n.) The motion of a flower in following the apparent movement of the sun, from the east in the morning to the west in the evening.
(n.) Circumnutation.
Example Sentences:
(1) The effect on the signal intensities of cerebrospinal fluid (CSF) and iophendylate (Pantopaque) and on CSF-iophendylate contrast was studied in vitro with a small-nutation-angle (alpha) gradient refocused magnetic resonance (MR) imaging technique (GRASS) as alpha, repetition time (TR), and echo time (TE) were varied.
(2) 2D 27Al nutation MAS NMR was used to corroborate the line assignment for the as-synthesized and the rehydrated AlPO4-17.
(3) The families that do not show consistent differences are not necessarily harbouring nutations at the same locus, or the same mutation at any particular locus.
(4) The mutation which makes T7 DNA sensitive to the endonuclease is separable from the amber nutation and located between am28 and am233 (gene 6).
(5) Solid-state 27Al NMR spectra of several aluminophosphate molecular sieves have been recorded with conventional magic-angle spinning (MAS), double-rotation (DOR) and quadrupole nutation with fast MAS.
(6) Enhanced resolution was obtained in the quadrupole nutation experiment at certain radiofrequency pulse strengths.
(7) There was a high correlation between measurements obtained with the variable nutation and partial saturation techniques.
(8) The one phase is the intermediate phase where dilatation of the cervix is almost complete and where there is an instinctive reflex that delivery is going to take place and this is very strong, and this is what starts off the oscillation (contra-nutation) of the sacrum and full engagement.
(9) The apparent T2 is influenced by the magnitude of the nutation angle inhomogeneity across the slice and paradoxically is not always more accurate with larger numbers of echoes.
(10) The accuracy of measurement of the spin-lattice relaxation time (T1) in biological systems using the variable nutation angle method is discussed using computer simulations.
(11) The spin nutation properties of frequency selective (space selective in combination with a magnetic field gradient) trains of radiofrequency micropulses were studied in a numeric model.
(12) Cross-polarization magic-angle spinning 13C and 15N NMR, rotational-echo double resonance 13C NMR, and delays alternating with nutation for tailored excitation-difference 13C NMR spectra have been obtained from lyophilized cell walls of Bacillus subtilis grown on a synthetic medium containing D,L-[2-13C, 15N]aspartate and D-[1-13C]alanine.
(13) Transparent pulses are defined by the property of having no net effect on stationary spins, while selectively nutating and dephasing flowing spins.
(14) This "variable nutation" techniques was investigated using a T1 phantom.
(15) We conclude that the variable nutation method may allow measurement of T1 relaxation times with a significant reduction in acquisition time compared to partial saturation techniques.
Precession
Definition:
(n.) The act of going before, or forward.
Example Sentences:
(1) Self-reported and observer-rated signs and symptoms of nicotine withdrawal were assessed precessation and 2, 7, 14, 30, 90, and 180 days postcessation in smokers who quit on their own for 30 days.
(2) This review of basic physics of nuclear magnetic resonance (NMR) discusses precession of magnetic nuclei in a static external field, introduces the concept of the rotating frame, and describes excitation of nuclei by an RF field.
(3) By allowing a free precession interval before signal acquisition, time is left for field gradients to be switched and for undesirable transients to decay.
(4) We report in vitro and in vivo MR studies of hemorrhage using the gradient-echo pulse sequence, FISP (steady state free precession) and FLASH (spoiling of transverse magnetization) at 1.5 Tesla.
(5) Precession photographs from these crystal forms are very alike, suggesting the molecular packing to be similar in all three forms.
(6) Crystals were analyzed using precession photography and were assigned to trigonal space group R32 with unit cell dimensions a = b = 115 A, c = 385 A.
(7) The results obtained in a previous study using 131I fibrinogen in cancerous patients suggested a local intravascular clotting precess.
(8) According to the study of the 8 cases published since 1956 and of this personal case the precession of a benign porosyringeal tumour seems probable but has never been proved.
(9) Canavanine also affects regulatory and catalytic reactions of arginine metabolism, arginine uptake, formation of structural components, and other cellular precesses.
(10) The temperature, concentration and Larmor precession frequency dependences can be well described by the conception of fast exchange in a simple biphasic model of water molecules rotation in the first hydration layer with slight anisotropy of motion.
(11) The space group and unit cell dimensions were determined with a precession camera and a four-circle diffractometer to be C222(1), and a = 157.1 A, b = 85.5 A, and c = 79.7 A, respectively.
(12) Microperfusion of pertubular capillaries failed to demonstrate urinary precession of 3H-gentamicin over 14C-inulin, a finding which argues against a rapid transtubular secretory flux of gentamicin.
(13) When this residual phase coherency is utilized in conjunction with the fast SSFP (steady-state free precession) technique, both the FID and the echo signals can be obtained.
(14) Steady-state free precession (SSFP) pulse sequences can produce magnetic resonance (MR) images rapidly, in which cerebrospinal fluid (CSF) is several times more intense than the other tissues.
(15) The detector is stationary which causes a distortion that is negligible for precession angles less than 10 degrees.
(16) There exists an age-related precession of taurine uptake values by brush border membrane vesicles prepared from nursing rats from youngest to oldest.
(17) Naturally processed peptide fragments bound to MHC class II molecules are peptides of 13-17 amino acids which appear to be precessively truncated from the carboxy terminus, perhaps after binding to the MHC class II molecule.
(18) The space group was determined using screenless small-angle precession photographs, and was confirmed by analyzing area detector diffraction data with the XENGEN programs for indexing and refinement.
(19) In a series of 18 consecutive cases of acute significant inversion trauma to the ankle, a three-dimensional fast imaging with steady-state precession pulse sequence (3D FISP) was performed.
(20) Results indicated that a FISP (fast imaging with steady precession) sequence with a TR of 50 msec, TE of 15 msec, velocity compensation in the read and section-select directions, acceleration compensation in the read direction, anisotropic volume, and a 1.25-mm partition thickness produced three-dimensional angiographic MR images that were accurate and reproducible in the depiction of the major intracranial vessels.