(n.) One of a class of caustic bases, such as soda, potash, ammonia, and lithia, whose distinguishing peculiarities are solubility in alcohol and water, uniting with oils and fats to form soap, neutralizing and forming salts with acids, turning to brown several vegetable yellows, and changing reddened litmus to blue.
Example Sentences:
(1) Significant amounts of 35S-labeled material were lost during the alkali treatment.
(2) The results also suggest that both alkali metals most probably have been delivered to the suckling pups and some of their toxic effect was retarded.
(3) Rabbits eating Rabbit Chow excreted a very alkaline urine, but rats eating the same diet excreted much less alkali when expressed per kilogram of body weight.
(4) From these findings it is concluded that cardiac performance and carbohydrate metabolism are accelerated in alkali and depressed in acid perfusion, and that myocardial metabolism could be affected by pH not only secondary to the change of performance but also by itself.
(5) Electrophoresis, Sephadex chromatography, and ultrafiltration studies showed that the alkali-soluble, water-soluble cell wall antigen is comprised of lipid, polysaccharide, and protein and has a molecular weight range of 30,000 to 50,000.
(6) [Na+],[Cl-)and[alkali]were determined in the alkaline gastric juice samples (pH greater than 7.0).
(7) Plants placed in pure acid and alkali solutions were also able to neutralize the medium.
(8) TFP produced a more discrete block in the repair of alkali-labile lesions in DNA.
(9) Activation of GV by monochromatic 450-nm radiation causes two specific DNA changes in human P3 cells in culture as shown by alkaline elution techniques: single-strand breaks (i.e., alkali-labile sites plus frank strand scissions) and DNA-to-protein covalent bond crosslinks.
(10) Keratan sulphate was isolated from bovine intervertebral disc and bovine nasal septum after hydrolysis with proteinases and treatment with dilute alkali.
(11) It was necessary to avoid CsCl banding of procapsids in their preparation as this treatment altered both their pI and their sensitivity to alkali dissociation into 14S subunits.
(12) In these muscles, two kinds of mRNA for the cardiac myosin alkali light chain, identical with those in ventricular muscle, were expressed and their relative amount in each tissue was almost the same as that in ventricular muscle.
(13) The enzymes were detected and characterized by agarose gel electrophoresis of alkali-denatured digestion products.
(14) The alkali cations selectivity sequence induced by ETH1811 is Li+ (1) greater than Na+ (0.08) greater than K+ (0.02) greater than Cs+ (0.008).
(15) When the monomer was further dissociated into constituent subunits in strong alkali or at high concentrations of SDS, the CD spectrum disappeared almost completely, indicating loss of the asymmetric interactions of the chromophoric heme a with its immediate environments, consisting of the subunit assembly.
(16) Addition of alkali to the culture media results in decrease of cell GAD activity, whereas increase of enzyme level occurs only in cells growing in unbuffered media.
(17) Chain breaks as measured in alkali were also measured and found to be enhanced by the dye; the ratio of breaks per iodine loss was 0.9.
(18) Alkali hydrolysates of elastins contained a radioactive peak that was eluted between proline and leucine.
(19) Under limiting concentration conditions, BLM and NCS induce alkali-labile sites in DNA without a subsequent cleavage of the chain.
(20) Hydrolysis with mild alkali yields anhydroretinol, as it does for synthetic retinyl phosphate, with absorption maxima at 388, 368, and 346 nm.
Metalloid
Definition:
(n.) Formerly, the metallic base of a fixed alkali, or alkaline earth; -- applied by Sir H. Davy to sodium, potassium, and some other metallic substances whose metallic character was supposed to be not well defined.
(n.) Now, one of several elementary substances which in the free state are unlike metals, and whose compounds possess or produce acid, rather than basic, properties; a nonmetal; as, boron, carbon, phosphorus, nitrogen, oxygen, sulphur, chlorine, bromine, etc., are metalloids.
(a.) Having the appearance of a metal.
(a.) Having the properties of a nonmetal; nonmetallic; acid; negative.
Example Sentences:
(1) As with other elements, the interest here is the potential effect of environmental acidification on environmental behavior in ways that are relevant to human exposure to these metalloids.
(2) The effects of the well established carcinogenic metals or metalloids (As, Be, Cr, Ni), hypothetically carcinogenic but well-established cocarcinogenic metals (Cd, Pb, Co) and weak co-carcinogenic metals (Al, Cu, Fe, Zn) and the antagonism between Mg and these metals were studied on the ionic transfer through the isolated human amnion.
(3) New information about the toxic effect of some metals and metalloids and about their kinetics of absorption, distribution and excretion in experimental animals, and particularly in man, is necessary for elaborating suitable biological exposure tests.
(4) Selenium (Se) is a metalloid with chemical properties closed to those of sulfur, but they can not substitute for one another in vivo.
(5) In order to invalidate or confirm the affirmation that non antithyroid sulphide molecules alter the measure of the thyroid fixation rate of iodine 131 we undertook on the rat: on one hand a kinetic study of thyroid fixation of sodium thiosulfate labelled with sulphur 35, which showed a very low captation not exceeding 0,01% of injected radioactivity; on the other hand the study of the effects of some sulphide molecules on thyroid fixation of iodine 131 in the rat: sodium thiosulfate, association of sodium thiosulfate + metalloidal sulphur + methionine, carbutamide and dimethylsulfoxyde in various kinds of dose administration and periods.
(6) Main group metals and metalloids were surveyed for the identification of species that can either donate or accept methyl groups.
(7) Diethyl maleate, indocyanine green and sulfobromophthalein (BSP), which decreased biliary excretion of GSH, significantly diminished excretion of antimony and bismuth into bile indicating that hepatobiliary transport of these metalloids is GSH-dependent.
(8) In recent years, however, it has become clear that several metals and metalloids undergo transformations in mammalian tissues and that metabolism may have important implications in clinical pharmacology, toxicology, and environmental health.
(9) Proportionally to their biliary excretion rates, these metalloids generate increased biliary excretion of GSH probably because they are transported from liver to bile as unstable GSH complexes.
(10) The potential impact of acidic deposition on As and Se in soils cannot readily be assessed with respect to human exposure, but it would appear that the behavior of these metalloids in poorly buffered, poorly immobilizing soils, e.g., sandy soils of low metal hydrous oxide content, would be most affected.
(11) Biological monitoring of exposure to metals and metalloids involves not only determination of these elements in selected body fluids and tissues but, in some cases, also determination of a certain biochemical indicator which signalises the presence of the monitored element in the organism.
(12) Methylcobalamin (methyl-B12) has been implicated in the biomethylation of the heavy metals (mercury, tin, platinum, gold, and thallium) as well as the metalloids (arsenic, selenium, tellurium and sulfur).
(13) Details of the kinetics and mechanisms for biomethylation of arsenic are presented, with special emphasis on synergistic reactions between metal and metalloids in different oxidation states.
(14) The exchange rates for metals and metalloids between sediments, soils, water and aquatic biota are discussed in terms of normal and acidified ecosystems.
(15) The occupational history highlighted heavy exposure to inhalation of ash derived from mineral oil combustion and containing several elements, metals and metalloids, including vanadium and nickel.
(16) Available information on acid precipitation and the environmental behavior of these metalloids do, however, permit some preliminary conclusions to be drawn.
(17) Over the past 15 years, these methods have led to the establishment of causal factors in metal- and metalloid-induced toxicity.
(18) The present studies in rats aimed to determine whether antimony and bismuth, other metalloids in group Va of the periodic table, also possess similar properties.
(19) The abnormal life--potentially the death--of the cell can be restored by a metalloid--lithium--which is nearly as common as sodium in the mineral world.
(20) In this report we present details of the mechanisms for biological methylation of certain metals and metalloids with special emphasis on those elements that are widely dispersed in the biosphere.