Role of Parallel Solenoidal Electric Field on Energy Conversion in 2.5D Decaying Turbulence with a Guide Magnetic Field

We perform 2.5D particle-in-cell simulations of decaying turbulence in the presence of a guide (out-of-plane) background magnetic field. The fluctuating magnetic field initially consists of Fourier modes at low wavenumbers (long wavelengths). With time, the electromagnetic energy is converted to plasma kinetic energy (bulk flow+thermal energy) at the rate per unit volume of J · E for current density J and electric field E . Such decaying turbulence is well known to evolve toward a state with strongly intermittent plasma current. Here we decompose the electric field into components that are irrotational, E ir, and solenoidal (divergence-free), E so. E ir is associated with charge separation, and J · E ir is a rate of energy transfer between ions and electrons with little net change in plasma kinetic energy. Therefore, the net rate of conversion of electromagnetic energy to plasma kinetic energy is strongly dominated by J · E so, and for a strong guide magnetic field, this mainly involves the component E so,∥ parallel to the total magnetic field B . We examine various indicators of the spatial distribution of the energy transfer rate J ∥ · E so,∥, which relates to magnetic reconnection, the best of which are (1) the ratio of the out-of-plane electric field to the in-plane magnetic field, (2) the out-of-plane component of the nonideal electric field, and (3) the magnitude of the estimate of current helicity

Bipolar Plasma Kinetic Vaporization Resection in the Management of Benign Anastomotic Stricture after Rectal Cancer Surgery: A Report of 12 Cases

Background: Postoperative anastomotic stricture is a common complication after kinds of rectal cancer surgery, especially in low anterior resection and anal retention patients. Currently, various of treatments including anal expansion, endoscopic dilation and also surgery are applied with different efficacy and safety. Besides, bipolar plasma kinetic vaporization resection is a technique used to be applied for benign prostatic hyperplasia with minimally invasion and high safety. To the best of my knowledge, it had not been reported to be applied for narrow scars after rectal surgery.Methods: To analysis retrospectively the clinical data of 12 patients who suffered anastomotic strictures after rectal cancer surgery in the First Hospital of Jilin University from Feb 2015 to December 2017. Result：All of them were successfully treated by the technique of once bipolar plasma kinetic vaporization resection in 8 cases, twice in 3 cases, and more times in 1 cases without occurrence of additional complications. Conclusions: Demonstrated by these limited cases, bipolar plasma kinetic vaporization resection would be applied as an alternative method in the treatment of postoperative anastomotic strictures due to its advantages as well as its effectiveness and safety.

Dissection Methods in Abdominoplasty: A Systematic Review and Meta-Analysis

Abdominoplasty is one of the most common cosmetic procedures performed worldwide. Despite recent advances in surgical technique, the risk of complications remains high. The advantages of using various dissection devices as a method of flap elevation in abdominoplasty remains unclear. A systematic search was undertaken to identify studies comparing electrocautery dissection with scalpel dissection and plasma-kinetic energy-based dissection methods in abdominoplasty. A meta-analysis was performed using the selected studies. Seven studies were analyzed. These studies included a total of 1143 patients who underwent abdominoplasty using electrocautery (n = 617), steel scalpel (n = 457), or plasma dissection (n = 69). A meta-analysis was conducted, which showed an overall reduction in incidences of seroma, operative time, and length of hospital stay in the scalpel dissection group compared with the electrocautery group. The plasma dissection group showed a reduction in rate of postoperative wound infection and hematoma, as well as a reduction in drain output and length of hospital stay, compared with the electrocautery group. There are few studies comparing outcomes using different dissection techniques in abdominoplasty. These studies are small and heterogeneous in design. However, using plasma-kinetic energy-based devices or scalpel dissection appears to be associated with reduced complication rates, shorter operative time, lower drain volumes, and a reduction in the length of hospital stay.