Different alkali metal atoms are observed to donate electrons to CF(3)Br molecules that are oriented in space. For collision energies high enough to overcome the Coulomb attraction, a positive ion/negative ion pair is observed and mass-analyzed using coincident time-of-flight mass spectroscopy. The alkali metal cation and various negative ions are observed. The most abundant negative ion is the...

We investigate the effects of adding periodic stimulation to a generic, conductance-based neuron model that includes ion concentration dynamics of sodium and potassium. Under conditions of high extracellular potassium, the model exhibits repeating, spontaneous, seizure-like bursting events associated with slow modulation of the ion concentrations local to the neuron. We show that for a range of...

A flow injection system for the potassium speciation in fortified wines, using two detectors placed in series, is described. The free, or ionized form, is monitored in a tubular-shaped potassium ion-selective electrode, and the total potassium content in a flame emission spectrometer used as end-of-line detector. Potassium determinations can be carried out in a linear range from 300 to 2000 mg ...

We report spectrophotometric methods for quantifying sodium and potassium in serum and plasma without sample pretreatment or solvent-extraction steps. The methods are based on novel chromogenic ionophores characterized by molecular structures highly preorganized for binding, which result in exceptionally high sensitivity and selectivity (negligible responses to sodium at 80 to 200 mmol/L in the...

The asymmetric unit of the title salt, K(+)·C(13)H(14)BF(3)NO(2)·0.5H(2)O, consists of two derivatized indolyltrifluoridoborate anions, two potassium cations and one water mol-ecule. Within the indolyltrifluoro-borate anions, the least-square planes consisting of the carboxyl group and the adjacent quarternary C atom of the tert-butyl groups deviate significantly from coplanarity with the indol...

The purpose of this study was to establish a model of trigeminal neuralgia (TN) through an approach from lower edge of cheekbone and to observe the functional changes in the voltage-gated potassium currents in the cultured trigeminal ganglion (TG) neurons. Thirty Sprague-Dawley male rats were divided into two groups, the sham-operated (sham) group and the operated group. The TN model was carrie...

Patch clamp measurements of excised inside-out patches of Arabidopsis thaliana plasma membrane reveal at least two ion channels which conduct either potassium or chloride. The conductance of the potassium channel ranged from 5 to 70 picosiemens depending on KCl concentration. The conductance increased linearly with increasing cytoplasmic-side [KCl]; the extent of this dependence declined as ext...

Voltage-gated ion channels play a fundamental role in the generation and propagation of the cardiac action potential by acting synergistically to produce an ionic current across cellular membranes. Abnormalities of heart ion channel activities that lead to loss or gain of function (channelopathies) are often associated with disruption of the coordinated propagation of electrical activity of the...