[Thermal distribution in ablation of squamous cell carcinoma skin tumors using irreversible electroporation]

Irreversible electroporation is a new treatment modality for skin tumors ablation. In order to successful treatment, all of tumoral tissues must be exposed to intense electric field. In addition, the heat that produced during the surgery has adverse effect on recovery procedure. This study was done to evaluate the thermal distribution in ablation of squamous cell carcinoma skin tumors using irreversible electroporation. In this study numerical modeling by finite element was used for determination of electrical and thermal distribution in healthy and tumoral tissues. Three-Dimensional Model was done using MR imaging of patient with squamous cell carcinoma in FEMLAB v3.5a software. Electric field distribution determined using Laplace equation and distribution of thermal damage calculated using bioheat equation and Arrhenius equation. This calculation was done for different geometry parameters of needle and plate electrodes. Thermal damage of first-degree burn was not observed in any cases. However in high voltage, volume with temperature above 43[degree sign]C reach to 10% of tumoral tissue and 3% of healthy tissue. The study show that the voltage applied to the electrodes and the distance between the electrodes can have the greatest impact on the thermal and electrical distributions. Although needle electrode showed better electric coverage in tumoral area. This study showed that it can be possible to select optimized electric and geometric parameter to select electrode for complete tumor ablation, control of thermal damage in tumoral and healthy tissues

Does whole body exposure to GSM-950 MHz electromagnetic fields affect acquisition and consolidation of spatial information in rats?

This study was planned to examine the effects of whole-body exposure to GSM-950 MHz electromagnetic fields [EMFs] on acquisition and consolidation of spatial memory in rats using a water maze task. In experiment 1, the animals were given two blocks of five trials per day for three consecutive days in a water maze task. The interval between blocks was 4h. Before each training session, the animals were exposed to 950 MHz EMFs for 45 min with lower-[0.835 mW/cm[2]] or higher-power [1.166 mW/cm[2]] densities. In experiment 2, the animals were given two blocks of 5 trials with a 3 min interval between blocks. Immediately after the last trial, they were exposed to EMFs for 45 min with lower-or higher-power densities. In both experiments, 48 h after the last training day a 60 s probe test was done. Results from experiment1 [pre-training exposure to EMFs] indicated no significant differences in performances of exposed and non-exposed groups either during acquisition [learning] or during probe test [memory retention]. Results from experiment 2 [post training exposure to EMFs] also indicated no significant differences among groups during acquisition or probe test. In these experiments, no effect of exposure to 950 MHz on acquisition or consolidation of spatial navigation of rats in a water maze was detected