Novel platinum bipolar electrode for irreversible electroporation in prostate cancer: preclinical study in the beagle prostate

The exposure of the prostate to high electric field strength during irreversible electroporation (IRE) has been extensively investigated. Multiple monopolar electrodes, however, have risks of organ piercing and bleeding when placing electrodes. A novel bipolar electrode made of pure platinum and stainless steel was developed for prostate cancer ablation. Voltages of 500 and 700 V were applied to the beagle prostate with this electrode to evaluate ablated tissues and their characteristics. IRE procedures were technically successful in all dogs without procedure-related complications. The current that flowed through the anode and cathode while applying 500 and 700 V were 1.75 ± 0.25 A and 2.22 ± 0.35 A, respectively. TUNEL assays showed that the estimated ablated areas when applying 500 and 700 V were 0.78 cm2 and 1.21 cm2, respectively. The minimum electric field strength threshold required for induction of IRE was 800 V/cm. The platinum electrode was resistant to corrosion. The IRE procedure for beagle prostates using a single bipolar electrode was technically feasible and safe. The novel bipolar electrode has great potential for treating human prostate cancer with fewer IRE-related complications.

COD removal from leachate by electrocoagulation process: treatment with monopolar electrodes in parallel connection

This study examines the removal of chemical oxygen demand (COD) from landfill leachate generated from the municipal landfill site of Bingol, Turkey. The effect of parameters such as current density, pH, and inter-electrode distance during the electrocoagulation (EC) process on COD removal of the process was investigated. Moreover, for COD removal, the energy consumption and operating costs were calculated for iron electrode under the EC conditions. COD removal efficiency was 72.13% at the current density of 16 mA m−2, pH of 8.05, and the inter-electrode distance of 9 mm at the detention time of 60 min with iron electrode and the COD concentration was reduced from 6,100 mg L−1 to 1,700 mg L−1 by EC. The highest value of the electrical energy and electrode consumptions per kg of COD in the optimum conditions were determined as 0.055 kWh kg−1 COD and 3.43 kg kg−1 COD and the highest operating cost value was found to be 1.41 US$ kg−1 COD for 0–60 min time intervals.

Modelling of a bipolar stent-based electrode for thermal radio frequency ablation of tumours located in hollow organs

Purpose – In this paper a numerical simulation analysis of a modified stent-based electrode is introduced to be used as a bipolar electrode for radio frequency ablation of tumours located in hollow organs. The purpose of this paper is to study the possibility of achieving a more regular volume of induced lesion with the presented electrode without imperilling the ductal organ where the tumour is located. Design/methodology/approach – Three types of bipolar electrode configurations were considered, formed by two, three and five tubular segments. Numerical simulations were performed considering a tumour located in the bile duct, where two important blood vessels – the portal vein and the hepatic artery – have a significant impact due to the convective heat transfer caused by the blood flow (heat sink effect) which significantly affects the shape of lesion that is intended to induce in order to destroy the tumour. Findings – The results obtained show that the five-segment electrode arrangement allows a regular volume for the induced lesion, independently of the different values of applied voltage considered. Originality/value – The presented work introduces a numerical simulation analysis on a modified based-stent electrode previously studied. In this case, the electrode is configured so it can be used as a bipolar electrode, i.e., active and ground electrode are placed in the same device. Besides the results evinced by the obtained results, this kind of electrode avoids eventual skin burns that might occur due to the need of the return electrodes when monopolar electrodes are used.

A comparative study of the new xylarate germanium (IV) complexe with lithium (xygerm-1), lithium chloride and valproic acid to the amphetamine-enhanced self-stimulation reactions in rats

Aim. To estimate the effect of novel lythium bis(µ-xylarato)dihydrogermanate (IV) (Xygerm-1) on reinforcing properties of the lateral hypothalamus self-stimulation in rats compared to the reference drugs (lithium chloride and valproic acid) in rats with amphetamine-induced self-stimulation. Methods. To form a model of the brain self-stimulation, nichrome monopolar electrodes were implanted bilaterally in the lateral hypothalamic nucleus, followed by morphological control, and 7-10 days after the operation, the rats were trained to press a pedal for electrical stimulation of the brain. The effects of self-stimulation were assessed by analyzing the maximum rate of pedal pressing and the self-stimulation threshold. Study of the test compounds effects had been started when average self-stimulation threshold values varied by less than 10% for three consecutive sessions of the brain self-stimulation. Xygerm-1 (300-1800 mg/kg), valproic acid (30-300 mg/kg) and lithium chloride (25-200 mg/kg) were introduced as intraperitoneal injections to animals of the corresponding study groups (6 rats each). At the next stage of the experiment, effects of Xygerm-1, lithium chloride and valproic acid on amphetamine-induced (dose 0.5 mg/kg) brain self-stimulation reaction increase were studied at the same animal groups. Results. At the first stage of the experiment Xygerm-1 (1200 and 1800 mg/kg), lithium chloride (100 and 200 mg/kg) and valproic acid (300 mg/kg) had significantly increased self-stimulation threshold. High doses of Xygerm-1 and lithium chloride (1800 and 200 mg/kg correspondingly) had relevantly decreased the average self-stimulation rate. There was also a tendency for the average self-stimulation rate to decrease in animals administered valproic acid, though, not statistically significant. The use of Xygerm-1 and lithium chloride induced the dose-dependant self-stimulation threshold increase, decreased by the use of amphetamine sulfate. Rather high doses of Xygerm-1 and lithium chloride (1800 and 100 mg/kg correspondingly) had also blocked amphetamine-induced increase in pedal pressing rate. Studied doses of valproic acid did not altered the amphetamine-induced brain self-stimulation reaction increase. Conclusion. The novel compound bis(µ-xylarato)dihydrogermanate (IV) has a strong influence on behavior, in particular on the brain reward systems, which is similar to the action of lithium chloride and differs from the effect of valproic acid.

Role of the diaphragm in trunk rotation in humans

The objectives of the present study were to test the hypothesis that the costal diaphragm contracts during ipsilateral rotation of the trunk and that such trunk rotation increases the motor output of the muscle during inspiration. Monopolar electrodes were inserted in the right costal hemidiaphragm in six subjects, and electromyographic (EMG) recordings were made during isometric rotation efforts of the trunk to the right (“ipsilateral rotation”) and to the left (“contralateral rotation”). EMG activity was simultaneously recorded from the parasternal intercostal muscles on the right side. The parasternal intercostals were consistently active during ipsilateral rotation but silent during contralateral rotation. In contrast, the diaphragm was silent in the majority of rotations in either direction, and whenever diaphragm activity was recorded, it involved very few motor units. In addition, whereas parasternal inspiratory activity substantially increased during ipsilateral rotation and decreased during contralateral rotation, inspiratory activity in the diaphragm was essentially unaltered and the discharge frequency of single motor units in the muscle remained at 13–14 Hz in the different postures. It is concluded that 1) the diaphragm makes no significant contribution to trunk rotation and 2) even though the diaphragm and parasternal intercostals contract in a coordinated manner during resting breathing, the inspiratory output of the two muscles is affected differently by voluntary drive during trunk rotation.

Removal of Remazol Turquoise Blue (G-133) and Polyvinyl Alcohol (PVA) by Electrocoagulation using Monopolar and Bipolar Electrodes

This study aims to investigate color and COD removal efficiencies of electrocoagulation (EC) process for dye solutions simulated by using polyvinyl alcohol (PVA) and reactive dyestuff of Remazol Turquoise Blue (G-133). The two different electrode configurations, namely monopolar and bipolar, were examined to find out the better alternative intensifying the performance of the process. The results obtained from these tests show that an EC cell with bipolar electrodes has produced slightly higher color and COD removal efficiencies than that of an EC cell with monopolar electrodes. The best removal efficiencies have been found for the both electrode configurations under the conditions that the time of electrolysis is 30 min, the constant direct current (DC) value 0.75 A and the initial pH value 3. Consequently, the bipolar electrode configuration (BPEC) has yielded 72.7 percent COD and 99.8 percent color removals while the monopolar electrode configuration (MPEC) producing 65.2 percent COD and 99.6 percent color removals.