(1) Some mechanisms that can provide catalysis of phosphoryl transfer through a metaphosphate-like transition state are reviewed briefly.
(2) Both at the substrate level and at the membrane level, orthophosphate energization to metaphosphate, by removal of an oxide anion (O2-), brings about a decrease in pKa with the concomitant dissociation of the two protons (2 H+), whereas de-energization of metaphosphate to orthophosphate, by addition of an oxide anion, brings about an increase in pKa with the concomitant fixation of two protons.
(3) As part of a comprehensive effort to evaluate the toxicological potential of calcium sodium metaphosphate fiber (Phosphate Fiber), the in vitro cytotoxicity of the fiber in cultured cells was studied.
(4) A metaphosphate intermediate appears to be involved.
(5) Calcium metaphosphates (CMP's)--a unique class of phosphate minerals possessing polymeric structures, [Ca(PO3)2]n, and having refractive indices of approximately 1.54-1.59-- are optically compatible with resins such as BIS-GMA.
(6) The fibers were rock wool [average diameter (D) = 6.1 microns, average length (L) = 296 microns], fiberglass (D = 0.65 microns, L = 16.8 microns), potassium titanate fiber (D = 0.36 microns, L = 7.17 microns), calcium sulfate fiber (D = 1.0 microns, L = 17.8 microns), basic magnesium sulfate fiber (D = 0.45 microns, L = 22.4 microns), and metaphosphate fiber (D = 2.38 microns, L = 64.1 microns).
(7) The results indicated that one of the two test dentifrices, containing 0.3% triclosan, 2% of a copolymer, and 0.76% sodium monofluorophosphate in an insoluble sodium metaphosphate abrasive system, significantly reduced plaque formation by 16% when compared to the placebo dentifrice.
(8) Detailed analysis of appropriate 31P nuclear-magnetic-resonance spectra shows that under the usual laboratory conditions, carbodiimide-induced condensation of orthophosphoric acid in a number of solvents leads to condensation only slightly beyond the metaphosphate composition in the presence of strong tertiary amines; whereas in the absence of amine, the condensation proceeds into the ultraphosphate region about halfway between the metaphosphate and phosphoric anhydride compositions.
(9) With arylsulphonyl chloride as condensing reagent monomeric nucleotide derivative B (nucleoside metaphosphate or its pyridinium adduct) is the highly reactive intermediate.
(10) The occurrence of linear condensed polyphosphates and cyclic condensed metaphosphates was studied by means of pulse-labeling with 32P-orthophosphate (3--5h) in a number of Phaeophyceae species: Pylaiella litoralis, Ilea fascia, Ectocarpus siliculosus and also Rhodophyceae species: Ceramiumdeslongchampsii, C. rubrum, Rhodomela confervoides, Porphyridium purpureum and P. aerugineum.
(11) In an experiment to ascertain the degradability of calcium sodium metaphosphate (CSM) fiber in vitro, 32P-labeled CSM fiber was incubated in media with or without rat lung epithelial cells (LEC) or rat alveolar macrophages (RAM).
(12) It is therefore suggested that, for the enzymatically catalyzed hydrolysis of phosphate compounds going via the formation of a metaphosphate intermediate, the role of any arginine residues at the active site is primarily one of binding and positioning the substrate.
(13) Electronic energy--resulting either from electron excitation or localization--is the obligatory link between the different forms of energy (light, redox, acid-base, metaphosphate-orthophosphate) transducible by biochemical systems.
(14) Phosphates with multiple negative charges can react by way of the monomeric metaphosphate ion PO3- as an intermediate.
(15) Concentrative absorption of inorganic phosphate observed in the stripped and everted intestine of the carp disappeared, when Na concentration of the Ringer solution was reduced from 150 to 7 mM, or when orthophosphate was replaced with metaphosphate.
(16) In this study we examined the shearing adhesive strength between a calcium metaphosphate glass-ceramic (CMP) and various luting materials.
(17) Three basic energy-transducing systems in bioenergetics, namely, redox, acid-base and metaphosphate-orthophosphate, couple between them through the acylium cation (Equation: see text)-carboxylate-anion (R-COO-) pair.
(18) For ketimines having carboxylate or phosphonate groups substituted on the beta-carbon atoms of the keto acid residue, there is a hydrogen ion or metal ion-activated covalent bond pathway which involves a shift of electron pairs toward the coordinated ketimine nitrogen, leading to beta-gamma, C-C or C-P bond fission and release of carbon dioxide or metaphosphate, respectively.
(19) Two-dimensional cellulose thin layer chromatography revealed that in all species studied 32P-radioactivity was generally present in all oligopolyphosphates containing 2 to 7 phosphate residues, in cyclic metaphosphates (tri-, tetra-, penta- and hexametaphosphates) and in high-molecular-weight condensed phosphates which remained at the starting point.
(20) The fact that the "metaphosphate" (delta-5.1) first becomes detectable only at later stage of the activation and does coexist with pyrophosphate and triphosphate suggests that the pyridinium derivative of "metaphosphate" is most probably not directly formed from the hypothetical mixed anhydride or active "pseudourea" right at the beginning of the reaction of pdTac with TPS or DCC, but rather formed at later stage of the activation reaction from the degradation of the pyro- and triphosphates by the activating agent.
Salt
Definition:
(n.) The chloride of sodium, a substance used for seasoning food, for the preservation of meat, etc. It is found native in the earth, and is also produced, by evaporation and crystallization, from sea water and other water impregnated with saline particles.
(n.) The neutral compound formed by the union of an acid and a base; thus, sulphuric acid and iron form the salt sulphate of iron or green vitriol.
(n.) Fig.: That which preserves from corruption or error; that which purifies; a corrective; an antiseptic; also, an allowance or deduction; as, his statements must be taken with a grain of salt.
(n.) Any mineral salt used as an aperient or cathartic, especially Epsom salts, Rochelle salt, or Glauber's salt.
(n.) Marshes flooded by the tide.
(n.) Of or relating to salt; abounding in, or containing, salt; prepared or preserved with, or tasting of, salt; salted; as, salt beef; salt water.
(n.) Overflowed with, or growing in, salt water; as, a salt marsh; salt grass.
(n.) Fig.: Bitter; sharp; pungent.
(n.) Fig.: Salacious; lecherous; lustful.
(v. t.) To sprinkle, impregnate, or season with salt; to preserve with salt or in brine; to supply with salt; as, to salt fish, beef, or pork; to salt cattle.
(v. t.) To fill with salt between the timbers and planks, as a ship, for the preservation of the timber.
(v. i.) To deposit salt as a saline solution; as, the brine begins to salt.
(n.) The act of leaping or jumping; a leap.
Example Sentences:
(1) Samples are hydrolyzed with Ba (OH)2, and the hydrolysate is passed through a Dowex-50 column to remove the salts and soluble carbohydrates.
(2) Ursodeoxycholate was the only dihydroxy bile salt which was able to solubilize phospholipid (although not cholesterol) below the critical micellar concentration.
(3) Furthermore, recent investigations into the pharmacokinetics of lithium salts are dealt with.
(4) The influence of calcium ions on the electrophoretic properties of phospholipid stabilized emulsions containing various quantities of the sodium salts of oleic acid (SO), phosphatidic acid (SPA), phosphatidylinositol (SPI), and phosphatidylserine (SPS) was examined.
(5) The role of adrenergic agents in augmenting proximal tubular salt and water flux, was studied in a preparation of freshly isolated rabbit renal proximal tubular cells in suspension.
(6) An investigation of the constitutive ions of salts revealed that their effects were additive only in the case of salts that have no specific binding capability.
(7) Benzyloxycarbonylarginine p-nitrophenyl ester and other activated esters of N-a-sustituted arginine salts may be useful reagents for introduction of trypsin-labile protecting groups into peptide fragments for purpose of polypeptide semi-synthesis.
(8) The association constants K'A, KN, and K'N in the scheme (see article), were determined for the magnesium salts of ADP, adenyl-5'-yl imidodiphosphate AMP-P(NH)P, and PPi.
(9) In contrast to this, adrenalectomy decreased ANP levels markedly in the organum vasculosum laminae terminalis and preoptic periventricular nucleus, which are reportedly involved in the central regulation of salt and water homeostasis.
(10) For routine use, 50 mul of 12% BTV SRBC, 0.1 ml of a spleen cell suspension, and 0.5 ml of 0.5% agarose in a balanced salt solution were mixed and plated on a microscope slide precoated with 0.1% aqueous agarose.
(11) Transcription studies in vitro on repression of the tryptophan operon of Escherichia coli show that partially purified trp repressor binds specifically to DNA containing the trp operator with a repressor-operator dissociation constant of about 0.2 nM in 0.12 M salt at 37 degrees , a value consistent with the extent of trp operon regulation in vivo.
(12) Mixed micelles of bile salt and phospholipids inhibit the lipase-colipase-catalysed hydrolysis of triacylglycerols.
(13) The first one is a region with iodine insufficiency; the second one is a region where the people use table salt in excess.
(14) One cellulase is buffer-soluble, the other buffer-insoluble but extractable with high salt concentrations.
(15) If salt fluoridation could also be generalized, caries levels could be reduced to a fraction of their initial values.
(16) The major lipase in human milk is dependent on bile salts for activity and probably participates in intestinal digestion of milk lipids in the newborn.
(17) The strain was resistant to bile salts in TCBS medium and demonstrated several properties from a borderline of two Vibrio and Aeromonas species.
(18) Sodium taurolithocholate, a monohydroxy bile salt, does not affect the CD spectrum of CEase, and neither the di- or the monohydroxy bile salt activates the enzyme.
(19) It is therefore suggested that salt water adaptation triggers a cellular reorganization of the epithelium in such a way that leaky junctions (a low resistance pathway) appear at the apex of the chloride cells.
(20) Depending on the differential sensitivity of nuclear T-ag to extraction by salt and detergent, nuclear T-ag could be separated into nucleoplasmic T-ag, salt-sensitive T-ag and matrix-bound T-ag subclasses.