What's the difference between cation and selenonium?
Cation
Definition:
(n.) An electro-positive substance, which in electro-decomposition is evolved at the cathode; -- opposed to anion.
Example Sentences:
(1) The actions of the polyvalent cationic dye Ruthenium Red and the enzyme neuraminidase were studied at the frog neuromuscular junction.
(2) Interaction of viable macrophages with cationic particles at 37 degrees C resulted in their "internalization" within vesicles and coated pits and a closer apposition between many segments of plasmalemma than with neutral or anionic substances.
(3) On the other hand, the hydrophilic reagents, 1-ethyl-3-[3-(dimethylamino)-propyl]carbodiimide and N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline, did not affect organic cation transport.
(4) Kup is a separate K+ uptake system with relatively little discrimination in the transport of the cations K+, Rb+, and Cs+.
(5) To selectively stain polyanionic macromolecules of growth plate cartilage and to prevent artifacts induced by aqueous fixation, proximal tibial growth plates were excised from rats, slam-frozen, and freeze-substituted in 100% methanol containing the cationic dye Alcian blue.
(6) In general, enzyme activity was strongly reduced by heavy metal inorganic cations; less strongly by organometallic cations, some anions, and certain pesticides; and weakly inhibited by light metal cations and organometallic and organic compounds.
(7) Conflicting reports exist on the postprandial response of serum cationic trypsin like immunoreactivity (SCTLI).
(8) Frequent measurement of serum cation and appropriate replacement are recommended when high dose Cisplatin containing regimen is used in chemotherapy of neoplasms.
(9) Binding is inhibited by divalent and trivalent cations (Cd2+ and La3+ being most potent) and other calcium channel drugs (1,4 dihydropyridines, phenylalkylamines, benzothiazepines).
(10) The planar 7H-pyridocarbazole cations form stacks approximately parallel to b. Interactions between stacks occur by weak van der Waals forces.
(11) Bio-Rex 70, a carboxylic acid cation exchanger, is studied as a biological ion-exchanger resin model for cellular cytoplasm.
(12) 45Calcium has been used to compare the kinetics for the transport and bioaccumulation of this regulatory cation in keratinocyte cultures of a kindred with HPS (i.e., one HPS homozygote, one HPS obligate heterozygote, one normal family member, and healthy adult controls).
(13) Although GTP most potently inhibited [125I]beta h-endorphin binding in the presence of sodium, inhibition of [125I]beta h-endorphin binding by GTP was also observed in the presence of the monovalent cations lithium and potassium, but not the divalent cations magnesium, calcium, or manganese.
(14) The fungicidal activity of six rabbit neutrophil cationic peptides (NP) against resting (dormant) spores, preincubated (swollen) spores, and hyphae of Aspergillus fumigatus and Rhizopus oryzae was examined.
(15) No significant relationship was found between these urinary cations and blood pressure.
(16) Cation concentrations were determined in a stratified subsample (n = 89) of the study group.
(17) The cation leak identified in this manner is not prelytic, and it is fully reversible.
(18) Na+ could not be replaced for growth by any other cations or substances.
(19) When the concentration of Ca2+ in the medium was raised to 10 mM was the only extracellular divalent cation present, the depolarization in response to A23187 was increased to 11-8 mV.
(20) Mn2+ had dual effects, stimulating the ECP release in the absence of Mg2+ and Ca2+, and inhibiting the release in the presence of these cations.
Selenonium
Definition:
(n.) A hypothetical radical of selenium, analogous to sulphonium.
Example Sentences:
(1) Trimethyl-selenonium was the major form (61%) of selenium in urine.
(2) At 30 microM concentration, the charged sulfonium and selenonium salts possessed significant agonist activity while the corresponding neutral species were inactive, suggesting that a charged species is optimal for dopamine agonist activity.
(3) The novel choline analogs selenonium choline (SeCh) and acetylselenonium choline (ASeCh) have been examined for selected biological activities.
(4) The use of single-column ion chromatography with conductometric detection was shown to be useful for the analysis of sulfonium and selenonium ions.
(5) Complete separation of the trimethylselenonium ion from four other selenonium compounds was achieved, and good recovery of the compounds was obtained for the desalting and chromatographic procedures.
(6) Selenobetaine (SB) and selenobetaine methyl ester (SBME) are methylated selenonium derivatives that undergo metabolism to release methyl selenide and dimethylselenide, respectively, as primary metabolites.
(7) In a series of para-substituted aryl 2-chloroethyl selenides, a linear free energy relationship between the first-order rate constant, k'nbp and sigma p gave a rho value of -1.3, indicating that formation of a cyclic ethylene selenonium ion is the rate-controlling step for alkylation of 4-(4-nitrobenzyl)pyridine (NBP).