What's the difference between crystal and vitreous?

Crystal


Definition:

  • (n.) The regular form which a substance tends to assume in solidifying, through the inherent power of cohesive attraction. It is bounded by plane surfaces, symmetrically arranged, and each species of crystal has fixed axial ratios. See Crystallization.
  • (n.) The material of quartz, in crystallization transparent or nearly so, and either colorless or slightly tinged with gray, or the like; -- called also rock crystal. Ornamental vessels are made of it. Cf. Smoky quartz, Pebble; also Brazilian pebble, under Brazilian.
  • (n.) A species of glass, more perfect in its composition and manufacture than common glass, and often cut into ornamental forms. See Flint glass.
  • (n.) The glass over the dial of a watch case.
  • (n.) Anything resembling crystal, as clear water, etc.
  • (a.) Consisting of, or like, crystal; clear; transparent; lucid; pellucid; crystalline.

Example Sentences:

  • (1) Such a signal must be due to a small ferromagnetic crystal formed when the nerve is subjected to pressure, such as that due to mechanical injury.
  • (2) A comprehensive review of the roentgenographic features of calcium pyrophosphate crystal deposition disease (pseudogout) is presented.
  • (3) CW Nd:YAG light transmitted by fiber optic cable and sapphire crystal was applied transsclerally to the ciliary body of pigmented and albino rabbits.
  • (4) The crystal structure of the biological stain, "acridine orange," has been determined.
  • (5) Urinalysis revealed a low pH, increased ketones and bilirubin excretion, dark yellowish change in color, the appearance of "leaflet-shaped" crystals and increased red blood cells and epithelial cells in the urinary sediment, increased water intake, decreased specific gravity and decreased sodium, potassium and chloride in the urine.
  • (6) Early in the regression process, cholesterol esters are reduced at least partly by hydrolysis to yield cholesterol, some of which may crystallize and inhibit rapid regression.
  • (7) Here we determine the position of bound ADP diffused into the recA crystal.
  • (8) The virus material in these crystals had been subjected to treatment with EDTA at pH 8.0 before crystallization at pH 6.5.
  • (9) Results obtained show that chlorophyll is more active than other inhibitors studied and suggest a higher surface adsorption intensity on the primary sources of the crystal surface.
  • (10) The "Mg(2+)-Sarkosyl crystals" (M band) technique distinguishes between membrane-bound and free intracellular DNA.
  • (11) The molecular structure of the hexagonal crystal form of porcine pepsin (EC 3.4.23.1), an aspartic proteinase from the gastric mucosa, has been determined by molecular replacement using the fungal enzyme, penicillopepsin (EC 3.4.23.6), as the search model.
  • (12) In vitro experiments show that these macromolecules are able to interact with specific faces of different crystals, influencing both nucleation and crystal growth.
  • (13) 2 Each of the drugs significantly increased leucocyte cyclic AMP content within 3 h of the injection of crystals.
  • (14) For Kevin Phillips, just like Wilfried Zaha, this might have been his final act as a Crystal Palace player.
  • (15) In ancillary studies, multiple cycles of direct dissolution of UCB crystals revealed a progressive decrease in aqueous solubility of UCB as fine crystals were removed; this effect was minimal in CHCl3.
  • (16) Six dogs were instrumented with electromagnetic flow probes and subendocardial ultrasonic crystals.
  • (17) The crystallization of the lipase was successfully carried out.
  • (18) The values of the energy level distributions in crystals obtained from the measurements and analysis reported here are compared with those obtained by a different method for the same protein complex in frozen solution.
  • (19) The crystal structure of proteolytically modified human ACT has been solved at 2.7-A resolution (Baumann et al., 1991).
  • (20) These observations support our hypothesis that calcium pyrophosphate dihydrate crystal deposition in joints is regulated by the physical chemical gel state of the connective tissue matrix.

Vitreous


Definition:

  • (a.) Consisting of, or resembling, glass; glassy; as, vitreous rocks.
  • (a.) Of or pertaining to glass; derived from glass; as, vitreous electricity.

Example Sentences:

  • (1) Histologic examination of the anterior and posterior chambers and the vitreous led to a diagnosis of endophthalmitis caused by Coccidioides immitis infection.
  • (2) The distribution of polyanionic glycosaminoglycans (GAGs) in the developing mouse vitreous was studied histologically by P.A.S.
  • (3) Suspensions of isolated insect flight muscle thick filaments were embedded in layers of vitreous ice and visualized in the electron microscope under liquid nitrogen conditions.
  • (4) 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.
  • (5) That is cystoid macular edema is associated with incomplete PVD with vitreous contraction.
  • (6) Chemically isolated separate preparations of the non-aggregating protein-chondroitin-keratin sulphate (PCKS) fraction from the hyaline cartilage and hyaluronic acid (HUA) of the vitreous body and of the umbilicus were investigated by electron microscopy.
  • (7) The eye is of the closed vesicle type and is composed of retina, cornea, vitreous body, lens and optic nerve.
  • (8) In proliferative retinopathy, the mid-vitreous fluorophotometry readings were abnormally increased, correlating well with the extent of the peripheral angiographic changes (neovascularization).
  • (9) Because they prevent secondary capsular opacification and anterior vitreous propagation, it appears that such barrier-type implants should be systematically placed.
  • (10) The mean in the newborn-to-6-month-old group was 47.59 D; in the 12-18-month-old group it had decreased to 45.56 D. The cornea appears to stabilize at about 54 months, with an average reading of 42.69 D. Evaluation of 11 eyes diagnosed as having persistent hyperplastic primary vitreous revealed that eyes with this diagnosis generally have steeper corneas than normal eyes at any given age.
  • (11) The cortical vitreous of the normal (control) eye appeared to be a lamellar structure composed of sheets of collagen mesh.
  • (12) Four of 15 retinas unable to be attached by scleral buckling were reattached after the addition of a single vitreous operation.
  • (13) A case is presented of a Medallion intraocular lens that dislocated posteriorly into the vitreous cavity.
  • (14) We evaluated the efficacy of microspheres of biodegradable polymers as a slow releasing drug delivery system in the vitreous body.
  • (15) The concentrations are different in the various tissues and show a relationship to the distance from cornea to vitreous.
  • (16) Active transport of fluorescein across the blood-retinal barrier in the direction of vitreous to blood does not seem to be significant within the first 2 hr after fluorescein injection.
  • (17) This study was undertaken to determine if extracapsular lens extraction enhances the ability of common bacteria to infect the anterior segment of the eye and if the posterior lens capsule acts as a protective barrier denying the infectious process access to the vitreous body.
  • (18) After WGA-HRP injection into the vitreous cavity of one eye, terminal labeling was seen in the suprachiasmatic nucleus, dorsal and ventral lateral geniculate nuclei, pretectum and superficial layer of the superior colliculus.
  • (19) Experiences with surgical treatment of chronic endogenous uveitis in human patients have shown that vision-impairing axial opacities in the vitreous body can be removed by pars plana vitrectomy, and that a considerable decrease in the frequency and severity of uveitic relapses results.
  • (20) Ocular injuries were observed in 7 of the 10 cases and when present always included retinal, vitreous, and subdural optic nerve hemorrhages.