Traditionally, Corydalis tuber has been used for the control of pain including headache, stomach ache, and neuralgia. In the present study, modulation of the Corydalis tuber on glycine-activated ion current in the acutely dissociated periaqueductal gray (PAG) neurons was studied by a nystatin-perforated patch-clamp technique. High concentrations of Corydalis tuber elicited ion current, which wa...

The plant alkaloid ibogaine has promising anti-addictive properties. Albeit not licensed as a therapeutic drug, and despite hints that ibogaine may perturb the heart rhythm, this alkaloid is used to treat drug addicts. We have recently reported that ibogaine inhibits human ERG (hERG) potassium channels at concentrations similar to the drugs affinity for several of its known brain targets. There...

−− The spectrophotometric method for the determination of cuprous ions in solution presented by Anwar et al. (2000), has since been analyzed and improved, especially with regard to interference from iron and ion species commonly found in acid mine drainage (AMD). The reduction of cupric ions in the presence of ferrous ions, not considered by Anwar et al., renders this method unfeasible for cupr...

The electrostatic screening length predicted by Debye-H\"uckel theory decreases with increasing ionic strength, but recent experiments have found that the can instead increase in concentrated electrolytes. This phenomenon, referred to as underscreening, is believed result from ion-ion correlations and short-range forces such excluded volume interactions among ions. We use Brownian Dynamics simu...

A study of the transient potential signals obtained with a cation-selective electrode based on an ion-exchanger was carried out for solutions following individual cations at different concentrations: H+, Li+, Na+, K+, Rb+, Mg2+, Ca2+, choline (Ch+), acetylcholine (AcCh+), and procaine (Pr+). Three general types were distinguished depending value selectivity coefficient corresponding ion. princi...

The mechanism of ion conduction by potassium channels is one of the central issues in physiology. In particular, it is still unclear how the ion concentration and the membrane voltage drive ion conduction. We have investigated the dynamics of the ion conduction processes in the Kv1.2 pore domain, by molecular dynamics (MD) simulations with several different voltages and ion concentrations. By f...

One-point, Linear, Hyperbolic and Polynomial calibration approaches were adopted to elucidate the quantitative effectiveness of standard solutions of 10 to 800 ng/mL secobarbital by comparing theoretical and observed concentrations. Different concentrations of internal standard(IS), 50 and 200 ng/mL, were added to standard solutions for comparison purpose. Two GC column temperature programs, a ...

Ion-mediated electrostatic interactions play an important role in RNA folding stability. For a RNA in a solution with higher Mg(2+) ion concentration, more counterions in the solution can bind to the RNA, causing a strong many-body coupling between the bound ions. The many-body effect can change the effective potential of mean force between the tightly bound ions. This effect tends to dampen io...

The hammerhead ribozyme is generally accepted as a well characterized metalloenzyme. However, the precise nature of the interactions of the RNA with metal ions remains to be fully defined. Examination of metal ion-catalyzed hammerhead reactions at limited concentrations of metal ions is useful for evaluation of the role of metal ions, as demonstrated in this study. At concentrations of Mn2+ ion...