[Function control of implanted pacemakers using electronic oscillographs].

Several approaches to implementing amperometric detection for capillary electrophoresis have been reported. This report describes the development of a voltammetric detector for CE. The detector is designed to minimize distortion of the voltammetry due to ohmic potential drop. This was accomplished by using a cast Nafion detection cell at the end of the separation capillary. The cast Nafion detection cell provided a low-dead-volume, low-resistance cell that minimized ohmic potential drop and peak band broadening. The ability to detect the current due to oxidation of analytes superimposed on a large background current was also improved. A dynamic background subtraction scheme was used in which a second working electrode, positioned in the electrochemical cell but outside of the detection cell, was used to compensate for the background current in real time. The output of the compensating working electrode was subtracted from the output of the detecting working electrode prior to analog-to-digital conversion. Postexperimental digital background subtraction was also implemented. This approach provided optimal elimination of the background current with maximal detection of the analytical signal. The voltammetric detector developed produced high-quality voltammetric response of analytes with injected concentrations as low as 0.20 microM. The system was evaluated by obtaining CE voltammograms of a mixture of eight test phenolic acids.

Electrodes↗

PubMed1997

Impact of different electrode surface areas on validity of human electrogastrograms.

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Electrodes↗

PubMed1997

Stone disintegration: effect of shock wave projection and electrode age on this parameter in a standard stone model.

Despite the real effectiveness and successful results of shock wave application, the effect of some varying parameters, namely number of shock wave (SW) electrical discharge value (kV), projection of the shock waves and electrode age are still to be evaluated. By using a standard stone model, we evaluated the real effect of the projection of shock waves and electrode age on the degree of stone disintegration. Our results indicated no significant relationship between the kV value and the degree of stone disintegration. However, as the number of SW increased, the rate of disintegration became evident. On the other hand, application of the same number of SW from two different angles revealed more effective disintegration rate on standard stone model. Thus SW number, age of the electrode and the projection of shock waves seemed to be important in the disintegration of the stones.

Electrodes↗