(n.) A piece of glass, or other transparent substance, ground with two opposite regular surfaces, either both curved, or one curved and the other plane, and commonly used, either singly or combined, in optical instruments, for changing the direction of rays of light, and thus magnifying objects, or otherwise modifying vision. In practice, the curved surfaces are usually spherical, though rarely cylindrical, or of some other figure.
Example Sentences:
(1) These results demonstrate that increased availability of galactose, a high-affinity substrate for the enzyme, leads to increased aldose reductase messenger RNA, which suggests a role for aldose reductase in sugar metabolism in the lens.
(2) Based on several previous studies, which demonstrated that sorbitol accumulation in human red blood cells (RBCs) was a function of ambient glucose concentrations, either in vitro or in vivo, our investigations were conducted to determine if RBC sorbitol accumulation would correlate with sorbitol accumulation in lens and nerve tissue of diabetic rats; the effect of sorbinil in reducing sorbitol levels in lens and nerve tissue of diabetic rats would be reflected by changes in RBC sorbitol; and sorbinil would reduce RBC sorbitol in diabetic man.
(3) The significance of the differences in these two patterns of actin is discussed in terms of differences in the accommodative ability and static lens shape in these two animals.
(4) The epithelium of Brunner's gland stained intensely with Ricinus communis agglutinin-I (RCA-I), succinylated-WGA (S-WGA) and wheat-germ agglutinin (WGA), moderately with Bandeirea simplicifolia agglutinin-I (BS-I), Concanavalia ensiformis agglutinin (Con A) peanut agglutinin (PNA) and Ulex europaeus agglutinin-I (UEA-I) and occasionally with Dolichos biflorus agglutinin (DBA), Lens culinaris agglutinin (LCA) and soybean agglutinin (SBA).
(5) That is, he believes, to look at massively difficult, interlocking problems through too narrow a lens.
(6) The advantages of the incision through the pars plana ciliaris are (1) easier approach to the vitreous cavity, (2) preservation of the crystalline lens and an intact iris, and (3) circumvention of the corneal and chamber angle complications sometimes associated with the transcorneal approach.
(7) The third patient was using an extended-wear soft contact lens for correction of residual myopia.
(8) The cellularity depends on the type of the lens and the material of the lens and on the clinical picture of the disease.
(9) Although lens haemagglutinins were detected in 6 out of 7 rabbits, in only 3 of the 6 animals did the titre reach a maximum of 1:640.
(10) Dioptric aniseikonia was calculated between 1 month and 24 months after surgery (with Gruber's and Huber's computer program) on the basis of most recently obtained values (bulb axis length, depth of the anterior chamber, lens thickness, necessary refraction), and compared with subjective measurements taken with the phase difference haploscope.
(11) We propose that a channel with these properties could contribute to maintenance of lens transparency and fluid balance.
(12) Although the lens did not alter stereopsis, it did produce severe color discrimination losses for normal and dichromatic subjects.
(13) The general efficacy of this intraocular lens compared with other anterior chamber lenses was not addressed in this study.
(14) However, the monkey lens low molecular weight proteins differ from the human low molecular weight proteins in charge as well as molecular weight determined by SDS-PAGE.
(15) Fifty-five myopic naval personnel with no previous contact lens experience were put through a three-week study using these contact lenses.
(16) A Stryker turning frame was used during surgical removal of a posterior displaced lens.
(17) The biocompatibility and fixation of a new silicone intraocular lens was evaluated in the cat eye.
(18) Both organisms have previously been found to be sequestered in the posterior lens capsule by histological and microbiological examination of excised capsular specimens.
(19) Previous experiments had demonstrated that the receptors for the lectins soybean agglutinin (SBA), wheat germ agglutinin, concanavalin A and Lens culinaris agglutinin all were relatively uniformly distributed on both myoblasts and myotubes, and that SBA receptors were capable of rapid redistribution on myotubes but not myoblasts at 4 degrees C (Sawyer & Akeson, 1983).
(20) The relative permittivity and conductivity of rabbit eye lens were measured in the frequency domain between 2 and 18 GHz at temperatures of 37 and 20 degrees C. An analysis of the data suggested that a significant proportion of the bulk water in nuclear and cortical lens tissue may behave differently to pure water.
Vertex
Definition:
(n.) A turning point; the principal or highest point; top; summit; crown; apex.
(n.) The top, or crown, of the head.
(n.) The zenith, or the point of the heavens directly overhead.
(n.) The point in any figure opposite to, and farthest from, the base; the terminating point of some particular line or lines in a figure or a curve; the top, or the point opposite the base.
Example Sentences:
(1) CNV1 was recorded at the vertex while CNV3 was recorded at multiple electrode sites to assess topographical differences.
(2) Preceding or during movement, maximum ERD was observed in most cases in central-vertex regions.
(3) Brain stem electric responses, recorded with external electrodes on vertex and ear lobes, are excellent for audiometry of young children.
(4) Umbilical blood-gas status at elective cesarean section with oxygen inhalation for breech presentation (25 cases) was compared with that for vertex presentation (25 cases), so as to confirm the security of full-term breech fetuses delivered by cesarean section under spinal anesthesia.
(5) An evoked brain response can also be elicited simultaneously from the vertex response is affected to the same degree by several different aspects of visual stimuli as is the corresponding occipital response.
(6) N1 and P2 to the last preceding frequent stimulus, the rare (attended target) stimulus, and the following two frequent stimuli were evaluated using 6 reference-independent measures: latency (time of maximal potential range between any two locations), amplitude of maximal potential range, global field power, vertex (Cz) current source density, location of extreme potential, and location of potential centroid.
(7) AEPs were recorded to an "oddball" paradigm from vertex and left and right temporal electrodes.
(8) The MRBPs had earlier onsets during the first runs of skill acquisition than during later training sessions; they occurred earlier when they preceded a stimulus train than when they preceded a single stimulus; the onset was earlier over the vertex than over the premotor area.
(9) In addition, careful parametric baseline studies were performed in each cat to strengthen the evidentiary linkage between wave A as recorded from the vertex in these experiments and previous studies describing the origin and trajectory of wave A in the brainstem reticular formation and several regions of thalamus, including the intralaminar nuclei.
(10) Responses were recorded between needle electrodes placed on the vertex and the ipsilateral ear, with ground at the interorbital line.
(11) A model of sleep phasic events such as vertex waves, K complexes, delta waves and sleep spindles is proposed.
(12) The enhancement results have been confirmed for central brain vertex stimulation using the Sheffield magnet.
(13) Anodal stimulation at the vertex produced complex corticospinal volleys that could be recorded at both sites, with multiple waves analogous to the D and I waves documented in animal experiments.
(14) N140 and P190 (the "vertex potentials") are probably generated bilaterally in the frontal lobes, including orbito-frontal, lateral and mesial (supplementary motor area) cortex.
(15) An otherwise healthy five-year-old girl presented for evaluation of a large patch of erythematous scaling alopecia on the vertex of her scalp.
(16) Oxygen extraction in the breech (Mean: 49.0%) was higher than that in the vertex (32.9%).
(17) As it is quite unlikely that P3 generating sources are strongly active during the processing of the frequent stimulus, this effect is possibly due to a component overlap from the vertex potential.
(18) The frequency of congenital anomaly was also studied in 8,863 infants delivered by breech and vertex presentation.
(19) Carbon particles entering the subarachnoid space over the vertex of the cerebral hemispheres drained along selected paravascular and subfrontal pathways in the subarachnoid space to the cribriform plate and thence into nasal lymphatics and cervical lymph nodes.
(20) As it was not possible to collect sufficient material for valid conclusions on a series of patients with similar uterine activity, fetal size, uterine volume, cervical resistance, and lower uterine segment development; only women in normal labor without disproportion and delivered of infants in the occipitoanterior vertex presentation were included in the study.