(a.) Sour, sharp, or biting to the taste; tart; having the taste of vinegar: as, acid fruits or liquors. Also fig.: Sour-tempered.
(a.) Of or pertaining to an acid; as, acid reaction.
(n.) A sour substance.
(n.) One of a class of compounds, generally but not always distinguished by their sour taste, solubility in water, and reddening of vegetable blue or violet colors. They are also characterized by the power of destroying the distinctive properties of alkalies or bases, combining with them to form salts, at the same time losing their own peculiar properties. They all contain hydrogen, united with a more negative element or radical, either alone, or more generally with oxygen, and take their names from this negative element or radical. Those which contain no oxygen are sometimes called hydracids in distinction from the others which are called oxygen acids or oxacids.
Example Sentences:
(1) The amino acid sequence deduced from the nucleotide sequence contained both amino- and carboxyl-terminal sequences.
(2) F(420) is photolabile aerobically in neutral and basic solutions, whereas the acid-stable chromophore is not photolabile under these conditions.
(3) The high amino acid levels in the cells suggest that these cells act as inter-organ transporters and reservoirs of amino acids, they have a different role in their handling and metabolism from those of mammals.
(4) If ascorbic acid was omitted from the culture medium, the extensive new connective tissue matrix was not produced.
(5) The interaction of the antibody with both the bacterial and the tissue derived polysialic acids suggests that the conformational epitope critical for the interaction is formed by both classes of compounds.
(6) Arachidic acid was without effect, while linoleic acid and linolenic acid were (on a concentration basis) at least 5-times less active than arachidonic acid.
(7) An unsaturated fatty acid auxotroph of Escherichia coli was grown with a series of cis-octadecenoate isomers in which the location of the double bond varied from positions 3 to 17.
(8) The ability of azelastine to influence antigen-induced contractile responses (Schultz-Dale phenomenon) in isolated tracheal segments of the guinea-pig was investigated and compared with selected antiallergic drugs and inhibitors of arachidonic acid metabolism.
(9) After 4 to 6 hours of recirculation, accumulation of vasoactive amine, 5-hydroxytryptamine, its major metabolite, 5-hydroxyindole acetic acid, and its precursor amino acid, tryptophan were detected.
(10) Spectrophotometric determination of the sulfhydryl content in the animal tissue before (control) and after using 6,6'-Dithiodinicotinic acid is applied.
(11) This death is also dependent on the presence of chloride and is prevented with the non-selective EAA antagonist, kynurenic acid, but is not prevented by QA.
(12) However, four of ten young adult outer arm (relatively sun-exposed) and one of ten young adult inner arm (relatively sun-protected) fibroblasts lines increased their saturation density in response to retinoic acid.
(13) Microionophoretically applied excitatory amino acids induced firing of extracellularly recorded single units in a tissue slice preparation of the mouse cochlear nucleus, and the similarly applied antagonist 2-amino-5-phosphonovalerate (2APV) was demonstrated to be a selective N-methyl-D-aspartate (NMDA) receptor antagonist.
(14) The LD50 of the following metal-binding chelating drugs, EDTA, diethylenetriaminepentaacetic acid (DTPA), hydroxyethylenediaminetriacetic acid (HEDTA), cyclohexanediaminotetraacetic acid (CDTA) and triethylenetetraminehexaacetic acid (TTHA) was evaluated in terms of mortality in rats after intraperitoneal administration and was found to be in the order: CDTA greater than EDTA greater than DTPA greater than TTHA greater than HEDTA.
(15) Estimations of the degree of incorporation of 14C from the radioactive labeled carbohydrate into the glycerol and fatty acid moieties were carried out.
(16) The second amino acid residue influences not only the rate of reaction but also the extent of formation of the product of the Amadori rearrangement, the ketoamine.
(17) Leumorphin is a 29-amino-acid peptide derived from preproenkephalin B. Intracerebroventricular (i.c.v.)
(18) Hepatic lymph flow increased only after ethacrynic acid and mannitol administration.
(19) 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.
(20) A phytochemical investigation of an ethanolic extract of the whole plant of Echites hirsuta (Apocynaceae) resulted in the isolation and identification of the flavonoids naringenin, aromadendrin (dihydrokaempferol), and kaempferol; the coumarin fraxetin; the triterpene ursolic acid; and the sterol glycoside sitosteryl glucoside.
Etch
Definition:
(n.) A variant of Eddish.
(v. t.) To produce, as figures or designs, on mental, glass, or the like, by means of lines or strokes eaten in or corroded by means of some strong acid.
(v. t.) To subject to etching; to draw upon and bite with acid, as a plate of metal.
(v. t.) To sketch; to delineate.
(v. i.) To practice etching; to make etchings.
Example Sentences:
(1) After permeabilization, with attendant partial extraction, the preparation can be fixed, then viewed by either deep-etch replication, or by high-resolution scanning electron microscopy, with structure of interest revealed in deep view.
(2) The freeze-etch technique was used to study the morphology of Treponema refringens (Nichols).
(3) A thorough dental prophylaxis before acid-etching of enamel is often recommended.
(4) The results of the rapid-freeze and deep-etch procedure showed that the ridges observed by the surface replica method consisted of linear arrangements of elliptical particles on the ES face of the plasma membrane.
(5) All the summer deals in graphical, Etch-a-sketch form .
(6) When either predictability or bond strength was considered independently, several bracket systems, coupled with a particular etch time, had either high predictability or high bond strength.
(7) This demineralization was similar to enamel acid etched with 50% phosphoric acid for 2 mn.
(8) This study evaluated the bond strength between glass ionomer cements and laser-etched dentin.
(9) Acid etching smooths and cleans the dentinal surface.
(10) Examination of apposed replicas and deep-etched specimens indicated that at least some of the IMPs extend through the T. pallidum outer membrane and are exposed on the surface of the organism.
(11) Isolated appressed chloroplast membranes, highly enriched in photosystem II (PSII) activity, were examined by freeze-etch electron microscopy.
(12) The technique of freeze-etching for electron microscopy applied to isolated islets of Langerhans has permitted a successful evaluation of emiocytotic events on the cell surface.
(13) The tensile bond strengths of the bonding resin to the etched enamel surfaces were not significantly different.
(14) The etched porcelain laminate veneer is a new conservative treatment that offers a solution to fractured, discolored, and worn anterior teeth.
(15) SEM and TEM examinations suggested that dentinal collagen exposed by the etching but not entangled and impregnated by poly (4-META-co-MMA) easily deteriorated by water during the longer immersion.
(16) The performance of a commercial double-propane-jet freezer (Balzers QFD 101) has been assessed, for rapid freezing of fresh tissues in freeze-etch work.
(17) The purpose of this in vitro study was to determine the tensile bond strengths (TBS) of several orthodontic bonding systems and orthodontic brackets to enamel surfaces exposed to different etching procedures.
(18) We find that freeze-drying is the most reliable and easy method for molecules that withstand distilled water; freeze-etching can be successfully applied to transmembrane proteins (even in the presence of detergents or salt); the glycerol-spray technique provides an excellent alternative to the cryotechniques in particular for studies of single linear molecules.
(19) After acid etching, filtration produced a 32-fold increase in permeation.
(20) On the corresponding PF face of the plasma membrane, linear arrangements of the intramembrane particles (IMPs) of about 8 nm in diameter were observed by both the deep-etch and freeze-fracture methods.