(n.) A real or apparent libratory motion, like that of a balance before coming to rest.
Example Sentences:
(1) The simulation reproduces the amplitudes of the fast librational motions of the backbone N-H bonds determined from 15N nuclear magnetic relaxation data, as well as the crystallographic B-factors.
(2) This has provided information on the translational and librational motions of individual groups in the complex.
(3) Above about 52 degrees C cholesterol improves the order by decreasing the amplitude of the librational motions.
(4) In its thermal vibrations, the adenosine molecule behaves as two rigid segments with a torsional libration about the glycosidic bond of 14.4 deg2 at 123 K. The force constant for this libration, as determined from the diffraction data, is 73 (10) J mol-1 deg-2.
(5) In the 1970s, Princeton physicist Gerald K O’Neill envisioned 100,000-person colonies, stationed at what is known as the fifth Lagrangian libration point (L5) in the moon’s orbit – like a gravitational eddy where things stay put by themselves.
(6) The source of the entropic elastomeric force is demonstrated to be the result of internal chain dynamics, and the mechanism is called the librational entropy mechanism of elasticity.
(7) The librational motions are to some extent cooperative.
(8) A translational, librational, and screw analysis of the thermal parameters of endothiapepsin also supports a model in which the two parts can move relative to each other.
(9) Collectively these results suggest that hydrophobic interactions make contributions to elastin entropy at low extensions, but that librational mechanisms make larger contributions to the elastic restoring force at longer extensions.
(10) Many such motions reflect peptide plane librations that result from anticorrelated crankshaft rotations of psi i and phi i+1.
(11) 7 nsec at 40 degrees C) where the band has been assigned to a peptide librational mode.
(12) The amplitude of the base motion, modeled as a fast four-site libration, or diffusion in a cone, increased slightly with higher levels of hydration.
(13) The TLS model has also been applied to the whole protein molecule and shows that the average motion is approximately isotropic with little librational character.
(14) Calculations of the relative statistical weights of these conformations confirm earlier theoretical considerations on the importance of the librational free energy of stable conformations of peptides.
(15) Since the spin-lattice relaxation rate for the active R-state (immobilized) phosphate is similar to that observed in other phosphoenzymes of different size it is suggested that a librational motion on the nanosecond time scale may constitute a common spin-lattice relaxation pathway for phosphates in macromolecules.
(16) The absorption bands of the glycerol ester, phosphoryl, and choline groups were broadened upon hydration, suggesting the activation of the librational or torsional motion.
(17) The similarity of Raman frequencies for B-, A-, C-, and Z-DNA suggests that these modes originate from concerted motions of the bases (librations), which are not strongly dependent upon helix backbone geometry or handedness.
(18) Thus, while the rate of these transitions cannot be quantified, the simulated decay of these correlation functions is completely consistent with the physical picture in which the N-H vectors, in addition to fast librational motion, undergo large amplitude jumps between conformations stabilized by hydrogen bonds.
(19) By analogy this allows for the first assignment of a peptide librational mode in a naturally occurring polypeptide or protein.
(20) The hydrophobic side groups in the protein core show mainly translational motion, with mean-square librations of 20 deg2 which are similar to those found in some close-packed crystals of small organic molecules.
Surface
Definition:
(n.) The exterior part of anything that has length and breadth; one of the limits that bound a solid, esp. the upper face; superficies; the outside; as, the surface of the earth; the surface of a diamond; the surface of the body.
(n.) Hence, outward or external appearance.
(n.) A magnitude that has length and breadth without thickness; superficies; as, a plane surface; a spherical surface.
(n.) That part of the side which is terminated by the flank prolonged, and the angle of the nearest bastion.
(v. t.) To give a surface to; especially, to cause to have a smooth or plain surface; to make smooth or plain.
(v. t.) To work over the surface or soil of, as ground, in hunting for gold.
Example Sentences:
(1) The resulting dose distribution is displayed using traditional 2-dimensional displays or as an isodose surface composited with underlying anatomy and the target volume.
(2) Phospholipid methylation in human EGMs is distinctly different from that in rat EGMs (Hirata and Axelrod 1980) in that the human activity is not Mg++-dependent, and apparent methyltransferase I activity is located in the external membrane surface.
(3) To quantify the size of the lesion in mice, the area of the infarct on the brain surface was assessed planimetrically 48 h after MCA occlusion by transcardial perfusion of carbon black.
(4) Using monoclonal antibodies directed against the plasma membrane of Madin-Darby canine kidney (MDCK) cells, we demonstrated previously that a glycoprotein with an Mr = 23,000 (gp23) had a non-polarized cell surface distribution and was observed on both the apical and basolateral membranes (Ojakian, G. K., Romain, R. E., and Herz, R. E. (1987) Am.
(5) In the surface epithelial cells, the basolateral cell surface showed moderate enzymatic activity.
(6) Such an increase in antibody binding occurred simultaneously with an increase in the fluidity of surface lipid regions, as monitored by fluorescence depolarization of 1-(trimethylammoniophenyl)-6-phenyl-1,3,5-hexatriene.
(7) The role of Ca2+ in cell agglutination may be either to activate the cell-surface dextran receptor or to form specific intercellular Ca2+ bridges.
(8) The subcellular distribution of sialyltransferase and its product of action, sialic acid, was investigated in the undifferentiated cells of the rat intestinal crypts and compared with the pattern observed in the differentiated cells present in the surface epithelium.
(9) Even with hepatic lipase, phospholipid hydrolysis could not deplete VLDL and IDL of sufficient phospholipid molecules to account for the loss of surface phospholipid that accompanies triacylglycerol hydrolysis and decreasing core volume as LDL is formed (or for conversion of HDL2 to HDL3).
(10) A total of 555 caries lesions were registered on proximal surfaces, 49.1% being primary lesions in the enamel, 21.4% primary lesions into the dentin and 29.5% secondary lesions.
(11) Contact angles of Silafocon A and PMMA were relatively uninfluenced by front surface radii between 7.7 and 8.85 and 7.3 to 8.8 mm, respectively.
(12) These cells contained organelles characteristic of the maturation stage ameloblast and often extended to the enamel surface, suggesting a possible origin from the ameloblast layer.
(13) Together these observations suggest that cytotactin is an endogenous cell surface modulatory protein and provide a possible mechanism whereby cytotactin may contribute to pattern formation during development, regeneration, tumorigenesis, and wound healing.
(14) Our Ph1-positive ALL revealed B-cell lineage leukemia, since their surface phenotype were Ia+ and CD10+ and they have rearranged immunoglobulin JH genes.
(15) The complete nucleotide sequence of the gene for a cell surface protein antigen (SpaA) of Streptococcus sobrinus MT3791 (serotype g) was determined.
(16) To investigate the mechanism of enhanced responsiveness of cholesterol-enriched human platelets, we compared stimulation by surface-membrane-receptor (thrombin) and post-receptor (AlF4-) G-protein-directed pathways.
(17) Lysis of EAC4b,3b cellular intermediates formed to contain a low surface amount of C3b was more inhibited than was lysis of cells formed with a standard amount of C3b on the surface.
(18) After either 5 or 10 days of culture with both cytokines, intense immunofluorescent staining for Ia could be identified on the surface of greater than 80-90% of the viable islet cells.
(19) Within the capillary-perfused mucosa and muscularis (between 50 and 2000 microns from the urothelial surface), concentrations decreased by 50% for each 500-microns distance.
(20) Displacement of the surface of the cornea of bovine eyes after disruption of intact structures was investigated by means of holographic interferometry.