(n.) A rare element of the group of the earth metals, allied to aluminium. It occurs in certain rare minerals, as cerite, gadolinite, orthite, etc., and was so named from the difficulty of separating it from cerium, didymium, and other rare elements with which it is usually associated. Atomic weight 138.5. Symbol La.
Example Sentences:
(1) This was apparent by standard flux techniques only in low (65 mM) Na solutions, but was readily discernible in normal Na (125 mM) with the "lanthanum-residual" technique.
(2) Lanthanum nitrate used in this investigations is a valuable marker of the intercellular spaces.
(3) Lanthanum inhibits calcium uptake, protein secretion and K+ efflux induced by carbachol without impairing protein discharge stimulated by norepinephrine through the beta-adrenergic receptor.
(4) At every stage studied, neutralized lanthanum used as an ultrastructural tracer was seen filling the intercellular clefts and junction domains.
(5) The enhancement of lanthanum binding was reduced by both H1 and H2 receptor antagonists.
(6) Lanthanum can be used as a bidirectional inhibitor of micropinocytosis.
(7) Increasing the concentration of lanthanum from 0.1 to 10 mM in both the serosal and mucosal media produced a progressive decrease in tissue calcium retention and calcium transport.
(8) Moreover, lanthanum itself as well as lanthanides other than cerium, e.g., gadolinium and didymium (praseodymium, neodymium), were successfully applied and can be recommended as capture agents for phosphatase cytochemistry.
(9) Measurement of (140)La uptake by the living skin shows that lanthanum moves across the external surface of the skin readily, into and out of a compartment that has a limited capacity and is bounded on its internal side by a barrier impermeable to lanthanum.
(10) The shape regeneration of Ca2+-loaded cells, however, is blocked by lanthanum owing to Ca2+-pump inhibition.
(11) A tight junctional network, which shows some permeability to the lanthanum tracer, is located at the apical end of the cells.
(12) Human spermatozoa incubated in a strontium- or lanthanum-based medium, or T6 + 10% maternal human serum (HS) supplemented with 12 mM 8-bromo cyclic guanosine 3,5'-monophosphate and 10 mM imidazole for a 4-hour period before transfer to fresh T6 + 10% HS for a further 6 hours, demonstrated a significant increase (P less than 0.05) in acrosomal loss compared with T6 + 10% HS for a total 10-hour incubation.
(13) Using lanthanum tracer, we investigated the ultrastructure and the cell membrane permeability of mouse cardiac muscles in the early stage of severe burns.
(14) The lanthanum fluoride electrode activity coefficients.
(15) Only when mitochondria were disrupted did lanthanum gain access to internal sites on mitochondrial membranes.
(16) Moreover, the deposition of abnormal lamellar body contents resulted in the formation of clefts in the intercellular spaces at the stratum granulosum-stratum corneum interface, resulting in increased permeability through these domains shown by lanthanum perfusion.
(17) During either sustained diuresis (five animals) or vasopressin-induced antidiuresis (four animals), individual surface convolutions of distal convoluted tubules or early cortical collecting ducts were preserved for ultrastructural examination by intraluminal microperfusion with a glutaraldehyde-formaldehyde fixative followed by a second microperfusion with a lanthanum tracer.
(18) Lanthanum was rarely observed extravascularly and never extended to the enameloid matrix at the secretion stage.
(19) Perfusion of lanthanum chloride in saline for 15 min, followed by precipitation of lanthanum phosphate during fixation, resulted in lanthanum tracer distribution similar to that of horseradish peroxidase.
(20) The permeability of capillaries was investigated utilizing an in vivo injection of horseradish peroxidase (HRP) and an in situ perfusion of a balanced salt solution containing HRP and lanthanum chloride.
Praseodymium
Definition:
(n.) An elementary substance, one of the constituents of didymium; -- so called from the green color of its salts. Symbol Ps. Atomic weight 143.6.
Example Sentences:
(1) Moreover, lanthanum itself as well as lanthanides other than cerium, e.g., gadolinium and didymium (praseodymium, neodymium), were successfully applied and can be recommended as capture agents for phosphatase cytochemistry.
(2) The interaction of a series of beta-adrenoreceptor blocking agents with unilamellar dimyristoylphosphatidylcholine (DMPC) liposomes has been studied by proton nuclear magnetic resonance (1H-NMR) in the presence of praseodymium cation (Pr3+) at 30 degrees C. Addition of Pr3+ increased the splitting of the trimethylammonium group signals arising from the phospholipid molecules located at the internal and external surfaces of the bilayers.
(3) After oral administration, silipide exhibited a significant and dose-related protective effect against the hepatotoxicity induced by CCl4, praseodymium, ethanol and galactosamine.
(4) In the serum, phospholipid concentration fell to half the normal value within the first 24 hrs after praseodymium intoxication.
(5) On the other hand, energy transfer measurements using the lanthanide, praseodymium (Pr3+), as an acceptor indicate that IAEDANS is located 16-18 A from the binding site(s) of this calcium analog.
(6) Absorption difference and comparative absorption spectrophotometric studies on praseodymium(III) and fluorouracil, fluorocytosine, fluoroadenine, fluorothymine, fluorouridine, fluorocytidine, fluoroadenosine and fluorothymidine systems at pH approximately 5.5 and in different stoichiometries in 80% DMF medium have been carried out.
(7) The pretreatment of animals with phenobarbital normalized the microsomal enzyme impairment caused by praseodymium.
(8) The perovskite-like compounds RE(1-X)Pb(5)MnO(3) and RECoO(3), where RE (rare earth) is lanthanum, praseodymium, or neodymium, are active catalysts for the oxidation of carbon monoxide.
(9) The separate identification of the -N(+)-(CH(3))(3) groups located on the outside and inside of phospholipid bilayers observed in proton magnetic resonance spectroscopy upon addition of low concentrations of praseodymium ion was exploited to investigate the effects of incorporated cholesterol.
(10) The plot of the p2H dependence of the chemical shift of the outer trimethylammonium resonance of phosphatidylcholine liposomes with praseodymium ions present only on the outside of vesicles, results in a sigmoidal titration curve with its midpoint at p2H 1.5.
(11) for 15 days, praseodymium did not alter pharmacological effects and pharmacokinetic parameters.
(12) The addition of lanthanum chloride or praseodymium chloride in a peptide solution induces some conformational changes as displayed by several concerted variations of peptide resonances.
(13) Serum ornithine carbamoyltransferase (OCT) in rats poisoned with lanthanum, cerium and praseodymium.
(14) The serum ornithine carbamoyltransferase in relation to doses of lanthanum, cerium and praseodymium, administered intravenously as chlorides, was investigated.
(15) The analysis of the isolated solid complexes has suggested octa- and nona-coordination for praseodymium(III) in fluorinated nucleic bases and fluorinated nucleoside complexes.
(16) After intravenous injection of praseodymium nitrate, female Wistar rats develop fatty livers.
(17) The aim of this study is to investigate the quality of serum high density lipoprotein content as an index for the severity and time course of liver damage and regeneration following the administration of praseodymium.
(18) tris(1,1,1,2,2,3,3-heptafluoro-,7-dimethyl 1-4,6-octanedionato) praseodymium, to trilinolein has been found to induce a difference in the chemical shifts of the absorptions from the acids on the alpha- and beta positions.
(19) Intravenous injection of praseodymium nitrate into female Wistar rats results in liver damage.
(20) Upon addition of praseodymium ions, the phosphorus signals are shifted downfield.