Interaction of Sodium and Potassium Ions with Ionic Dextran Derivatives in Aqueous Solution with and without Added Salt

1973 ◽  
Vol 6 (3) ◽  
pp. 438-442 ◽  
Author(s):  
Hajime Noguchi ◽  
Kunihiko Gekko ◽  
Shio Makino
Keyword(s):  
Aqueous Solution ◽  
Potassium Ions ◽  
Sodium And Potassium ◽  
Added Salt

scholarly journals Alexdrandrite Effects and Pseudosymmetry in Aluminum Oxalates

2014 ◽  
Vol 70 (a1) ◽  
pp. C1017-C1017
Author(s):  
Ruthairat Nimthong ◽  
Matthias Zeller ◽  
Patimaporn Sungnoi ◽  
Sumpun Wongnawa ◽  
Chaveng Pakawatchai
Keyword(s):  
Aqueous Solution ◽  
Solid State ◽  
Color Change ◽  
Analysis Data ◽  
Tetragonal Symmetry ◽  
Potassium Ions ◽  
Solution Properties ◽  
Cubic Symmetry ◽  
Change Effect ◽  
Sodium And Potassium

Three chromium doped potassium aluminum oxalates, (K3[Al0.95Cr0.05(C2O4)3]·3H2O) "Blue", (K2/3Na7/3[Al0.95Cr0.05(C2O4)3]·4H2O) "RedCubic", and (K18{Na[Al0.964Cr0.036(C2O4)3]6}Cl·18H2O) "Red-Hexagonal" were prepared from aqueous solutions of K3[Cr(C2O4)3]·3H2O, K3[Al(C2O4)3]·3H2O and NaCl, and their solid state and solution properties were rationalized from their crystal structures, analysis data and solid state and solution UV-vis spectra. Crystals of "RedCubic" are characterized by a metrically cubic I-centered unit cell, but do have actual tetragonal symmetry derived by ordering of sodium and potassium ions not compatible with the apparent cubic symmetry. Results of 13C-NMR, EPMA/EDX, SC-XRD, and UV-Vis spectroscopies are discussed in relation to the compound's structures and color behavior. In aqueous solution RedCubic and Blue show the same greenish purple color and identical electronic absorption peaks. In the solid state, they have different colors and show slightly different absorption peaks. Their color behavior as well as the Alexandrite color-change effect observed in the two Red crystals are rationalized based on the compounds' absorption peaks.

Sodium and Potassium Fluxes in the Abdominal Nerve Cord of the Cockroach, Periplaneta Americana L

1961 ◽  
Vol 38 (2) ◽  
pp. 315-322
Author(s):  
J. E. TREHERNE
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Nerve Cord ◽  
Periplaneta Americana ◽  
Unit Area ◽  
Potassium Ions ◽  
Sodium Ions ◽  
Nerve Sheath ◽  
The Central Nervous System ◽  
Sodium And Potassium

1. The influx of sodium and potassium ions into the central nervous system of Periplaneta americana has been studied by measuring the increase in radioactivity within the abdominal nerve cord following the injection of 24NA and 42K. into the haemolymph. 2. The calculated influx of sodium ions was approximately 320 mM./l. of nerve cord water/hr. and of potassium ions was 312 mM./l. of nerve cord water/hr. These values are very approximately equivalent to an influx per unit area of nerve cord surface of 13.9 x 10-2 M cm. -2 sec.-1 for sodium and 13.5 x 10-12 M cm. -2 sec.-1 for potassium ions. 3. The relatively rapid influxes of these ions are discussed in relation to the postulated function of the nerve sheath as a diffusion barrier. It is suggested that a dynamic steady state rather than a static impermeability must exist across the sheath surrounding the central nervous system in this insect.

Tetanic hyperpolarization of single medullated nerve fibers in sodium and lithium

1976 ◽  
Vol 231 (4) ◽  
pp. 1033-1038 ◽  
Author(s):  
GM Schoepfle
Keyword(s):  
Steady State ◽  
Interspike Interval ◽  
Nerve Fibers ◽  
Repetitive Stimulation ◽  
Time Dependent ◽  
Potassium Ions ◽  
Current Densities ◽  
Medullated Nerve Fiber ◽  
Sodium And Potassium ◽  
Stimulation Of

Repetitive stimulation of a single medullated nerve fiber of Xenopus yields a succession of postspike voltage-time curves which are nearly coincident until attainment of a voltage that corresponds to that of the maximum attained by the normal postspike undershoot. Initially the interspike potential returns toward a resting level after this brief phase of hyperpolarization. However, as tetanization proceeds, a pattern of hyperpolarization develops with the result that, in the tetanic steady state, there exists a progressive hyperpolarization throughout each interspike interval. Extent of postspike hyperpolarization in terms of a deviation deltaVm from the resting level of membrane potential is approximated by the variation deltaVm = delta[MNa + MK]/[GNa + GK] where MNa and MK are current densities associated with active pumping of sodium and potassium ions and GNa and GK are corresponding time-dependent leak conductances. Tetanic hyperpolarization is reversibly abolished by cyanide and by exposure to lithium Ringer. Eventual reappearance of tetanic hyperpolarization in the presence of lithium Ringer suggests lithium pumping.

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