Very weak, 60-cps alternating current applied directly to the heart can cause ventricular fibrillation; greater current strength is required to induce ventricular fibrillation with a single shock delivered during the vulnerable period of the cardiac cycle. The present experiments were designed to examine the basis of this difference. The studies were performed in anesthetized open-chest dogs. T...

Effects of variation of the stimulus pulse shape on the excitation of a nonmyelinated nerve fibre were studied using a mathematical model based on the Hodgkin-Huxley equations. Efficiency of smoothly changing pulses was compared with that of rectangular pulses. For pulses shorter than the time to excitation, the rate of the stimulus rise did not determine the ability of a smoothly changing puls...

The laser strength of many materials under multipulse irradiation is usually significantly lower than their single-pulse irradiation. ‘accumulation’ effect reduces the impurity composition and mass evaporated substance from surface solid increases resistance solid, maximum ion charge ratio W in subthreshold above threshold region power density, without requiring additional radiation energy.

We present the effect of dual-pulse temporal shaping on ultraviolet nanosecond laser damage characteristics a fused silica exit surface in high fluence regime. The pre- and post-pulse have opposite effects behavior at pulse delay 20 ns. pre-pulse irradiation significantly increases main-pulse threshold, making it much higher than that single-pulse while has little threshold. For near-threshold ...

Our previous studies demonstrated that only a few days of housing in an enriched environment increases response strength and paired-pulse depression in the auditory cortex of awake and anesthetized rats [Engineer, N.D., Percaccio, C.R., Pandya, P.K., Moucha, R., Rathbun, D.L., Kilgard, M.P., 2004. Environmental enrichment improves response strength, threshold, selectivity, and latency of audito...

OBJECTIVE Intra-retinal placement of stimulating electrodes can provide close and stable proximity to target neurons. We assessed improvement in stimulation thresholds and selectivity of the direct and network-mediated retinal stimulation with intraretinal electrodes, compared to epiretinal and subretinal placements. APPROACH Stimulation thresholds of the retinal ganglion cells (RGCs) in wild...

This paper describes the passive Qswitch, based on polymer and organic dye BDN, of a pulsed Nd:YAG laser. Pulses of 27ns duration and peak power of 1.7MW for initial transmission of Q-switch 18.4% 0 T = have been obtained. We have obtained Q-switching efficiency of 77% for train of pulses of 31 and 76.2% 0 T = at the pump energy of 98J. We have also obtained the dependency of laser pulse charac...

background: this study is the first research investigating the possible effect of pulsed power signals on the characteristics of cortical bone by comparing the mechanical properties of this type of bone pre and post expose to pulsed power. methods: a positive buck-boost converter was applied to generate adjustable high voltage, high frequency pulses (up to 500 v and 10 khz). the functional beha...

This paper describes experiments that determine how the inter-pulse interval between rectangular pulses in a train of pulses alters the threshold of electroporation of 1-pamitoyl 2-oleoyl phosphatidycholine bilayer lipid membranes. The bilayers were exposed to a train of sixteen 100-micros duration pulses. Threshold voltage and the sequence number of the pulse in the train, where onset of the e...