The results are given of investigation of the inactivation of microbiological cultures in moist and dry states by low-temperature plasma of a low-power diffuse pulse-periodic discharge (up to 5 W) initiated in the air at a pressure of tens of torr and with an interelectrode gap of up to 10 cm. Escherichia coli and Staphylococcus epidermidis, inoculated onto test samples in an amount of ~10 8 , were used as reference cultures. It is found that a complete sterility of moist and dry test samples is attained after 15 minutes of treatment at an average discharge power of 0.3-0.4 W and 3-4 W, respectively. The inference is drawn that charged particles play a determining part in the bactericidal effect of the discharge.

This paper describes the development of a prototype high-power supply system for producing high-intensity magnetic and electric field impulses to be used in medical applications. After outlining the technical requirements and the main design features of the power source, the paper focuses on the numerical modelling of the double-coil design that is adopted. Theoretical predictions of the time history of the various currents in the circuit, and spatial and temporal variations of the electric and magnetic field distributions, are compared with experimental results obtained during full power testing of the system. Different ways are proposed by which the field intensities can be increased, and corresponding numerical simulations are presented. Initial physiological experiments have been undertaken with the prototype system. These have demonstrated the ability to stimulate structures such as the renal pacemaker, resulting in a ureteric peristaltic wave. The practical implications of this are discussed. References:'This work is funded by OTI(UK).