(n.) A luminous impression produced through excitation of the retina by some cause other than the impingement upon it of rays of light, as by pressure upon the eyeball when the lids are closed. Cf. After-image.
Example Sentences:
(1) Excitatory (positive) phenomena are subjective photic sensations (phosphenes) which can be elicited by transcranial magnetic stimulation over occipital parts of the skull.
(2) Stimulation substantially above threshold may produce a second conjugate phosphene, inverted about the horizontal meridian.8.
(3) Phosphenes appear immediately when stimulation is begun, and disappear immediately upon cessation of stimulation.18.
(4) The position of phosphenes in the visual field corresponds only roughly with expectations based on classical maps showing the projection of the visual field onto the cortex.14.
(5) The configuration of the phosphene fields hints at an excitation of the primary visual cortex (Brodmann's area 17).
(6) A visual prosthesis based on electrical stimulation of the visual cortex with an array of penetrating electrodes is expected to produce pixelized visual images consisting of punctate spots of light (phosphenes).
(7) The findings of these examinations correlated best of all with the clinical picture when visual evoked potentials (latency increase, decrease of the amplitude with atrophy augmentation, interhemispheric asymmetry in chiasmal and retro-chiasmal involvement) or the critical frequency of phosphene disappearance (reliably reduced if a disease was developing) were recorded.
(8) The phenomenon of deformation phosphenes was instrumental in prompting some pre-Socratic philosophers and Plato to conceive the idea that efferent light is emitted from the eye for the purpose of vision and a 'cone of vision' is formed by interaction with the external light.
(9) Because of the variation in repeated observations of the same phosphene pair, some method is needed to provide the 'best' fitting map to the observations.
(10) The increment threshold for a small spot of light on the phosphene in the dark is some 0.5 log td higher than for the same spot on a patch of light matched in appearance to the phosphene under the same conditions.5.
(11) Our findings indicate that the psychological component of the perception of electric and magnetic phosphenes must not be underestimated.
(12) For cortical phosphenes there is no sharp flicker fusion frequency, and probably no flicker fusion frequency at all.7.
(13) From experimental work on humans in 1905 with unencapsulated radium, it is known that approximately 80% of the intensity of the radium phosphene is from the beta-ray component and approximately 20% from the gamma-ray.
(14) Experiments are described in which the phosphene produced by passing alternating current of frequency 100 Hz through the eye is matched with a patch of light having the same apparent size.2.
(15) The prosthesis would create a pixelized visual sense consisting of punctate spots of light (phosphenes).
(16) The phosphenes appear on the left or right side of the visual field depending upon the direction of the coil currents, which determines whether the visual cortex of the right or the left hemisphere is activated.
(17) Electrical stimulation of the occipital cortex resulted in discrete photic sensations or "phosphenes" in two volunteers who had been totally blind for 7 and 28 years, respectively.
(18) Patterns of up to four phosphenes produced by four electrodes have been recognized.
(19) The influence of coil position on the size of electromyographic responses and on the intensity and position of phosphenes in the binocular visual field was studied.
(20) In the medial area (10-15 mm from the midline) of the occipital lobe, stimuli above the calcarine fissure resulted in phosphenes in the lower quadrant of the visual field.
Phosphine
Definition:
(n.) A colorless gas, PH3, analogous to ammonia, and having a disagreeable odor resembling that of garlic. Called also hydrogen phosphide, and formerly, phosphureted hydrogen.
Example Sentences:
(1) A number of the complexes showed potent cytotoxic activity in vitro and antitumor activity in vivo, with the phosphine-coordinated gold(I) thiosugar complexes demonstrating the greatest in vitro and in vivo activity.
(2) The phosphinic acid isosteres of di-, tetra- and hexapeptides containing a hydrophobic amino acid side chains at the P1-P'1 positions are powerful inhibitors of Human Immunodeficiency Virus protease.
(3) Quantitative analysis of type II pneumocytes showed that newborn rabbits had a distinct cell subpopulation in a region of low-angle light scatter and phosphine-3R fluorescence intensity similar to that previously reported on type II cells from adult rabbits.
(4) Substitution of the phosphinate linkage (PO2-CH2) for the peptide bond also gives potent inhibitors such as napthoyl-GlyP-C-Leu-Trp-NHBzl, the phosphinate analog of naphtholyl-Gly-Leu-Trp-NHBzl, which has a Ki of 10 nM.
(5) The incorporation of phosphine and phosphite ligands is described.
(6) The coordinated gold compound, 2,3,4,6-tetra-O-acetyl-1-thio-beta-D-glucopyranosato-S-triethyl phosphine gold (auranofin; Ridaura), was evaluated for antitumor activity in a variety of mouse tumor models.
(7) Dynamic studies showed that the combined action of phosphine and hydrofluoric acid damages the Krebs cycle reactions, dehydrogenization of isocitrate and synthesis of citrate in homogenized rat liver.
(8) Replacement of the scissile bond with the phosphinic analogue of Leu10-Val11 (1b) gave the most potent inhibitors, having IC50 = 7.5 x 10(-8) M for H-Pro-His-Pro-Phe-His-(1b)-Ile-His-Lys-OH and IC50 = 1.0 x 10(-7) M for Z-Arg-Arg-Pro-Phe-His-(1b)-Ile-His-NH2.
(9) Concentrations of [carboxyl-14C]procaine in blood of mice were increased threefold for 27 min by exposure to O-4-nitrophenyl diphenylphosphinate 2 hr prior to [carboxyl-14C]procaine injection ip, while there was no effect of O-4-nitrophenyl methyl(phenyl)phosphinate pretreatment.
(10) The yellow chromophore due to phosphine from raw polished rice had 2 absorption maxima, a strong one at 370-380 nm and a weaker one at 400-410 nm.
(11) These cells are distinguishable by the staining of their lamellar bodies with the fluorescent lipophilic dye, phosphine-3R and by their intensity of low-angle light scatter.
(12) The pro-S oxygen atom of the two phosphonate inhibitors and of the phosphinate group of the StaP inhibitor make very short contact distances (approximately 2.4 A) to the carboxyl oxygen atom, O delta 1, of Asp33 on penicillopepsin.
(13) This compound, which contains both carboxylic and phosphinic acid functional groups, is an HMG CoA reductase inhibitor currently under clinical investigation at the Bristol-Myers Squibb Pharmaceutical Research Institute.
(14) The two acidic groups of II are selectively esterified, first by methylation of the carboxylic acid with methanolic hydrochloric acid and then by formation of the hexafluoroisopropyl ester of the phosphinic acid.
(15) The ability of 3-aminopropyl(diethyoxymethyl)phosphinic acid (CGP 35348), 3-aminopropyl (hexyl)phosphinic acid (3-APHPA) and phaclofen to antagonize these responses was assessed.
(16) The hydroxamate Ro 31-4724 inhibits proteoglycan and collagen loss, whereas the phosphinic acid Ro 31-7467 selectively inhibits collagen breakdown in this model.
(17) No interferences from red phosphorus, phosphine, water vapor, or other common gases are significant.
(18) The reactivation and efficacy data, especially for CMPP, support the concept that oxime sensitive phosphinates may be useful as pretreatments against nerve agent intoxication.
(19) A new, single bolus method of in vivo blood pool imaging using a technetium Tc99m phosphine isocyanide complex (DEPIC) which binds to pre-albumin was evaluated in volunteers (n = 4) and patients (n = 20).
(20) As this was an indirect proof of malathion ingestion, it was assumed that phosphine had been ingested as well and that consequently this was the cause of death, because it is much more toxic than malathion and because it was continuously generated from not completely dissolved aluminiumphosphide tablets, while the children were still playing.