High-voltage Electric Field Research Articles

Development of a High-Voltage Pulsed Electric Field Sterilization Power Supply Using a New Topology Circuit

Traditional thermal sterilization technology is easy to implement and safe, but it will destroy food nutrition and change food taste. Therefore, people began to turn their attention to non-thermal sterilization. High-voltage pulsed electric field sterilization technology is one of them; it has attracted much attention because of its high efficiency and little damage to food. Different types of loads will cause serious trailing of the pulse falling edge. In view of this situation, this paper proposes a new topology circuit that combines a solid-state switch with a half-bridge Marx generator. It can be used for high-voltage pulsed electric field sterilization. By improving the structure of the classical Marx circuit, the high-voltage pulse power supply of the new topology circuit has the characteristics of steep rising edge and short falling edge delay; does not require isolation inductance or isolation resistance, which solves the isolation problem between the DC charging power supply and the high-voltage terminal; and has a good voltage-clamping function and load adaptability. The working process of the topology circuit under resistive, capacitive and inductive loads and the voltage clamping effect when the solid-state switch does not work properly in the discharge process are analyzed in detail. The power supply is composed of an adjustable DC power supply, five-stage half-bridge Marx generator and control protection circuit. A field programmable gate array (FPGA) is used as the controller to generate control signals, and optical fiber isolation is used to provide control signals for the main loop. The power supply can output a high-voltage square wave pulse with a voltage amplitude of 10 kV, maximum pulse number of 1000 per second, maximum pulse width of 20 μs, pulse rise time of smaller than 300 ns and short pulse drop time, and the repeated voltage amplitude, frequency and pulse width are adjustable, which can meet the requirements of a high-voltage pulse sterilization experiment.

Review of Aging Evaluation Methods for Silicone Rubber Composite Insulators

Silicone rubber insulation material is widely used for the external insulation of power systems. During the continuous service of a power grid, it will be seriously aged due to the influence of high voltage electric fields and harsh climate environments, which will reduce its insulation performance and service life and cause transmission line failure. How to evaluate the aging performance of silicone rubber insulation materials scientifically and accurately is a hot and difficult issue in the industry. Starting from the composite insulator, which is the most widely used insulating device of silicone rubber insulation materials, this paper expounds the aging mechanism of silicone rubber materials, analyzes the applicability and effectiveness of various existing aging tests and evaluation methods, especially discusses the magnetic resonance detection methods emerging in recent years, and finally summarizes the characterization and evaluation technology of the aging state of silicone rubber insulation materials.

Investigation of Consequences of High-Voltage Pulsed Electric Field and TGase Cross-Linking on the Physicochemical and Rheological Properties of Pleurotus eryngii Protein.

This study aimed to evaluate the effects of high-voltage pulsed electric fields (HPEF) and transglutaminase (TGase) cross-clinking on the physicochemical and rheological properties of Pleurotus eryngii protein (PEP). The results showed that HPEF increased α-helixes and β-turns but decreased β-folds. A HPEF at 1500 V/cm maximized the free sulfhydryl content and solubility of PEP. TGase formed high-molecular-weight polymers in PEP. TGase at 0.25% maximized the free sulfhydryl groups, particle size, and solubility; shifted the maximum absorption wavelength from 343 nm to 339 nm and 341 nm; increased α-helixes and β-turns and decreased β-folds; and showed better rheological properties. Compared with TGase cross-linking, HPEF-1500 V/cm and 1% TGase significantly reduced the free sulfhydryl groups, particle size, and solubility, produced more uniform network structures, and improved the rheological properties. These results suggest that HPEF can increase the cross-linking of TGase and improve rheological properties of TGase-cross-linked PEP by affecting the physicochemical properties.

Electrorheological effects of waxy crude oils under high-voltage AC electric field

Electrical treatment is an emerging method for improving the cold flowability of waxy crude oil by taking advantage of the electrorheological effect of the oil. Previous investigations have been focused on the effect of DC electric fields, with the effect of AC electric fields unknown. In this paper, experiments were made by exposing a waxy crude oil to AC electric fields with different frequencies, field amplitudes, and waveforms (square wave, sine wave, and triangle wave), and the viscosity and yield stress of the crude oil before and after the treatment were compared. It was found that the AC electric field could also improve crude oil cold flowability, but its electrorheological effect is somewhat weaker than that of a DC field under the same test conditions of treatment time and temperature. The lower the frequency, the stronger the effect. The essential reason could be the reduced force of charged particle migration under an AC field with a higher frequency. At the same frequency, the viscosity reduction is significantly improved with increased field strength amplitude. At the same field strength amplitude, the electrorheological effect of the three studied waveforms is ranked, from strong to weak, as square one, sinusoidal one, and triangle one, which is essentially attributed to the difference in the Root Mean Square (RMS) values of the field strength of each waveform. The higher the RMS value, the better the electrorheological effect. The main conclusion was confirmed by additional experiments using another crude oil.

Investigation of seed distribution on the surface of the depositing electrode from the grain material supply in the process of seed disinfection in electric fields

Purpose. Determination of technical and technological parameters of the electrotechnological means for presowing disinfection and stimulation of seeds in the electric field depending from the coefficient of distribution of seeds of crops on the surface of the precipitating rotating electrode. Methods. Analytical and calculation method using the structural and technological parameters of the working area of the means for pre-sowing disinfection and stimulation of seeds in an electric field and the data on the physical and mechanical properties of crop seeds. Results. A prototype of an electrotechnological device for pre-sowing disinfection and stimulation of crop seeds by a complex of electrophysical actions has been developed. The main condition for effective disinfection of seeds on the surface of a disk electrode in a high voltage electric field is the turning of the grains in the working space of the electrode system and their uniform distribution by the thickness of the grains in one layer on the surface of the rotating depositing electrode. This movement of the seed masses on the moving electrode ensures uniform treatment of each grain, which increases the efficiency of the process of disinfection of seed and grain material. To implement the process of pre-sowing disinfection and stimulation of seeds in an electric field, a structural and technological scheme of seed feeding and distribution in the working area of the electrode space of the device was developed Analytical dependences of feeding, expected productivity, and design parameters of the device scrapers on the coefficient of distribution of crop seeds on the surface of the depositing rotating electrode were obtained. They allow us to establish what the seed supply to the surface of the depositing electrode should be, and, accordingly, the performance of the prototype and the parameters of the scraper system to ensure the turning of the seeds in space and their uniform distribution by the thickness of the seeds in one layer on the surface of the rotating depositing electrode. Conclusions 1. The dependence of the supply of crop seeds to the surface of the electrode in terms of the expected productivity of the plant on the coefficient of seed distribution kz in the working area of processing was established. The distribution of seeds on the electrode surface in terms of specific gravity depends on the supply of seeds to the disk, the height and length of the scrapers. Uniform distribution of wheat, soybeans, corn, sunflower seeds on the surface of the disk in a single layer is achieved when kz = 1. In this case, the seed supply to the disk is in the range of 0.3–0.6 kg/s. 2. The parameters of the scraper system in terms of the length and height of the three scrapers depended on the type of crop seeds and their supply to the working area of the electrode system. The length of the first scraper for different seeds was in the range of values 229–246 mm, height – 18–24 mm; the second – 164–181 mm and 36–47 mm; the third - 83–132 mm and 54–71 mm, respectively. The specific weight of seeds on the surface of the disk is 1.3–3.7 kg/m2. The expected productivity of the prototype of the electrotechnological means for seeds of agricultural crops will be in the range of 0.7–2.1 t/h. Keywords: seed distribution coefficient, scraper system, seed disinfection, electric field, productivity, feeding, electrotechnological installation, pathogenic microflora, molds

Law of diffusion bubbles produced by high-voltage pulsed electric field in liquid

Pulsed electric field is a novel physical energy source for treating atrial fibrillation and tumor ablation, which has advantages over traditional thermal ablation, such as being non-thermal, short treatment time, tissue selectivity, and low contact pressure requirements. The diffusion bubbles generated during physical ablation may lead to gas embolism and silent cerebral events, with potential hazards such as tissue damage and cerebral ischemia. Previous studies have shown that the number of bubbles generated is correlated with the electrical properties of the treated object, pulse parameters (pulse waveform, treatment time and input energy), and electrodes. The number of bubbles are more significant at the cathode than at the anode, and the number of bubbles positively correlates with the input energy. However, to the best of our knowledge, no studies have been conducted to investigate the effects of ablation pulse parameters on diffusion bubbles. Therefore, in our experiment, a platform for producing pulses and observing diffusion bubble is built, and the needle-ring electrode we made realizes the capture and measurement of diffusion bubbles. Since pulses with a voltage of 3 kV and a pulse width of 100 μs are commonly used as ablation parameters for atrial fibrillation and tumor in pulsed field ablation (PFA), the pulse width of unipolar pulse is selected as 5, 10, 50, and 100 μs, and the number of pulses applied is 1. The pulse voltage is determined according to the parameters commonly used in PFA and the simulation calculation of the field strength distribution of the needle-ring electrode. After determining the parameters, this experiment explicitly investigates the relationships among diffusion bubbles and solution conductivity, pulse voltage, pulse width, input energy, and other parameters. Meanwhile, the size distributions of diffusion bubbles under different operating conditions are statistically investigated. Besides, the possible causes of diffuse bubbles are also explored. We evaluate the number of bubbles by measuring the cross-sectional area of the diffusion bubbles from a top-down perspective. The experimental results show that the area of diffusion bubbles generated in the liquid is positively correlated with pulse voltage and input energy; high conductivity and long pulse width can enhance the thermal effect and increase the area of diffusion bubbles; diffusion bubbles with a diameter larger than 100 μm are easily generated under high conductivity and high pulse width conditions. By speculating on the results, the electrolytic reaction may be the main source of diffusion bubbles when the needle electrode is the cathode. This study is expected to optimize future pulsed electric field ablation parameters.

The shape-retention and heat-tolerant elastic helix based on azobenzene-polyimide supramolecular assembly

Helical structures are ubiquitous in natural and engineered systems across multiple length scales, while they often exhibit nearly uniform radius and pitch. Utilization of biomimetic structure design to develop stretchable and robust 3D helical structures that are shape-preserving and heat-tolerant is of great interest. Herein, we devise flexible 3D helixes by supramolecular self-assembly and high voltage electric field orientation of molecular chains. The 3D helixes not only inherit buffering mechanics with exceptional shape-retention ability against cyclic stretching but also exhibit excellent heat-resistant quality. The results of the experimental tests confirm that the helix can recover its original shape without obvious residual strain and basically withstand after 2000 cycles under force loading of 10 cN. Such robust biomimetic materials hold great prospects in the fields of artificial muscles, wearable materials, and so on.

Fragmentation modeling of gas-phase ionic liquid clusters in high-voltage electric field

Cluster fragmentation subjected to a high-voltage electric field may play an important role in controlling the novel ionic liquid (IL) electrospray propulsion but has received little attention. In this work, the micro-fragmentation mechanisms of three kinds of IL clusters are numerically investigated using both static and dynamic approaches based on the quantum mechanical principles. Firstly, it reveals that the Coulomb interaction dominates the total inter-fragment energy for all three IL dimers, whereas the hydrogen-bonding interaction is identified as the main cause for the much slower break-up rate of the 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM-BF4]) dimer. In addition to the electrostatic interaction, the van der Waals interaction is a secondary energy component to which only a small fraction of atoms contribute significantly, regardless of IL cluster type. We find, only when the applied electric field is larger than 1 V/nm, the total inter-fragment energies of all three IL clusters start to dramatically reduced, indicating the possible occurrence of massive break-up. Secondly, ab initio molecular dynamics simulation further confirms that the [EMIM-BF4] negatively charged dimer is the most stable of three IL clusters under the identical conditions. As far as the high-voltage electric field is concerned, the one-parameter exponential function of break-up ratio versus time, routinely used in the field-free region, is not valid. Finally, on the basis of simulated results, a compound exponential-decay model is proposed, and the derived differential-sum equations from constant electric fields can be further applied to the non-uniform electric field.

Repeated irreversible electroporation in a locally advanced pancreatic cancer

It is reasonable to consider the technical possibility and oncological feasibility of the local tumor destruction in patients with locally advanced pancreatic cancer (PCa). Irreversible electroporation (IRE) is a non-thermal method of local tumor ablation, which uses non-thermal energy of high-voltage ultrashort electric fields localized between electrodes to create nanopores in the cellular wall with the following cellular death. The zone of impact can be accurately predicted using the location of the electrodes. A fairly clear and controlled ablation boundary without a clinically significant zone of perifocal tissue damage reduces the risk of accidental injury to the wall of a hollow organ. The method is based on a change in the permeability of the cell membrane and the development of apoptosis, which allows to act directly on the ducts and the great vessels infiltrated by the tumor without a high risk of damage. The presented case shows that IRE is advisable to use as a part of the combined treatment of patients with locally advanced PCa. There were no complications observed after the IRE. Radiological evaluations and pathologic reports showed an adequate long-term local control. Also, good results were obtained in the overall life expectancy, given that we are talking about unresectable ductal adenocarcinoma of the pancreas. The patient passed away in 39 months from the beginning of the treatment and in 26 months from the initial IRE. In case of local relapse, repeated electroporation with a good long-term result is also possible. The time to progression exceeded eleven months after electroporation performed for a local relapse. According to magnetic resonance imaging, both locoregional relapse and distant liver metastases were detected. The patient lived 16 months after a repeated IRE session and died of pulmonary embolism on the background of chemotherapy. Favorable prognostic factors are the presence of an objective response to previous conservative treatment, compliance with the parameters of electroporation, complete inclusion of tumor infiltration in the affected area.

Abstract 9835: Multi-Modality Imaging Assessment of Microbubbles and Cerebral Emboli in Left Ventricular Pulsed Field Ablation

Introduction: Pulsed field ablation (PFA) may have a superior safety profile compared to other ablation technologies, but the high-voltage electrical fields have the potential to cause gaseous microbubbles (MB), which may be associated with cerebral emboli. In this study, we evaluate the MB burden of a monopolar, biphasic PFA system (CENTAURI, Galaxy Medical), that delivers a waveform designed to limit MB generation. Methods: After anticoagulation with heparin, healthy and chronic MI swine (30 day survival after 90 minute coronary balloon occlusion) underwent PFA in the LV using an open-irrigated focal catheter under intra-cardiac echocardiography (ICE) guidance and monitoring of MBs. Two additional healthy control swine received 0.5 and 1 ml of air MBs through the lumen of the ablation catheter. Swine underwent brain MRI before and after PFA (or control air MB injection) with T1, T2, FLAIR, ADC and susceptibility- and diffusion-weighted imaging (DWI) interpreted by a neuroradiologist blinded to treatment group. Gross pathology and histology of brains with any MRI findings was performed by a neuropathologist. Results: Four healthy swine underwent 50 PFA applications and 5 chronic MI swine underwent 74 applications. No PFA-related MB formation was noted on ICE. Both control swine developed multiple acute emboli in the left thalamus and caudate on DWI, ADC and FLAIR brain MRI sequences in response to air MB injection (Figure). Of the 9 PFA swine, there were no ADC nor FLAIR sequence abnormalities. There was one instance of a hyperintense focus in the left putamen on the DWI trace image, but absence of ADC or FLAIR affirmation suggested it was artifact. Gross pathology and histopathology of this region did not detect any abnormalities (Figure). Conclusion: Catheter air MB injection caused MR-detectable cerebral emboli in swine. Focal monopolar biphasic PFA with CENTAURI does not generate MBs observable on ICE, and did not cause cerebral emboli in healthy or post-infarct LVs.

Reversible and Irreversible Effects of Electroporation on Contractility and Calcium Homeostasis in Isolated Cardiac Ventricular Myocytes.

Irreversible electroporation is an energy form utilizing high-voltage pulsed electric field, leading to cellular homeostasis disruption and cell death. Recently, irreversible electroporation has shown promising results for the treatment of cardiac arrhythmias. However, reversible and irreversible effects of pulsed electric field on cardiac myocytes remain poorly understood. Here, we evaluated the influence of a monophasic single electric pulse (EP) on the contractility, Ca2+ homeostasis and recovery of cardiac myocytes. Isolated rat left ventricular myocytes were electroporated using single monophasic EP of different durations and voltages. Sarcomere length and intracellular Ca2+ were simultaneously monitored for up to 20 minutes after EP application in Fura-2 loaded left ventricular myocytes. Lethal voltage thresholds were determined using 100 µs and 10 ms pulses and by discriminating cell orientation with respect to the electric field. Electroporation led to an immediate increase in intracellular Ca2+ which was dependent upon the voltage delivered to the cell. Intermediate-voltage EP (140 V, 100 µs) increased sarcomere shortening, Ca2+ transient amplitude, and diastolic Ca2+ level measured 1 minute post-EP. Although sarcomere shortening returned to pre-EP level within 5 minutes, Ca2+ transient amplitude decreased further below pre-EP level and diastolic Ca2+ level remained elevated within 20 minutes post-EP. Spontaneous contractions were observed after sublethal EP application but their frequency decreased progressively within 20 minutes. Lethal EP voltage threshold was lower in myocytes oriented perpendicular than parallel to the electric field using 100 µs pulses while an opposite effect was found using 10 ms pulses. Sublethal EP affected rat left ventricular myocytes contractility and disrupted Ca2+ homeostasis as a function of the EP voltage. Moreover, EP-induced lethality was preceded by a large increase in intracellular Ca2+ and was dependent upon the EP duration, amplitude and left ventricular myocytes orientation with respect to the electric field. These findings provide new insights into the effect of pulsed electric field on cardiac myocytes.

High-Frequency Pulsed Electric Field Ablation in Beagle Model for Treatment of Prostate Cancer

Simple SummaryAround 248,530 newly diagnosed in 2021, prostate cancer has been the most frequently diagnosed cancer in the USA. Rapid decellularization preserving acellular tissues is essential for accurate treatment and regeneration in affected areas. Our study aimed to assess the safety and efficacy of high-frequency pulsed electric field (HF-PEF) in a beagle model for the treatment of prostate cancer. We confirmed that HF-PEF of 1800 V/cm, 100 μs width, 2 ms interval successfully decellularized the prostate tissue after 4 hours, and the tissues were almost regenerated in 28 days. IRE with HF-PEF has therapeutic potential to treat prostate cancer while minimizing damage to the surrounding tissues.Conventional irreversible electroporation (IRE) with low-frequency pulsed electric field (LF-PEF) is used to induce cell death; however, it has several disadvantages including a long procedure time and severe muscle contraction due to high-voltage electric field. This study investigates a novel IRE protocol with high-frequency pulsed electric field (HF-PEF) of 500 Hz repetition to ablate the prostate tissue in beagles for treatment of prostate cancer. A finite element analysis was performed to validate optimal electrical field strength for the procedure. In total, 12 beagles received HF-PEF of 500 Hz and were sacrificed at 4 h, 4 days, and 28 days (3 each). The remaining three beagles underwent sham procedure. The outcomes of HF-PEF were assessed by histological responses. HF-PEF successfully decellularized the prostate tissues 4 h after the treatment. The prostate glands, duct, and urethra were well preserved after IRE with HF-PEF. The ablated prostatic tissues were gradually regenerated and appeared similar to the original tissues 28 d after IRE with HF-PEF. Moreover, electrocardiography and hematology demonstrated that IRE with HF-PEF did not seriously affect the cardiac tissue. HF-PEF was effective and safe in the beagle prostate and effectively induced the ablation and gradually recovered with cellular regeneration.

Electro Fluid Dynamics: A Route to Design Polymers and Composites for Biomedical and Bio-Sustainable Applications.

In the last two decades, several processes have been explored for the development of micro and/or nanostructured substrates by sagely physically and/or chemically manipulating polymer materials. These processes have to be designed to overcome some of the limitations of the traditional ones in terms of feasibility, reproducibility, and sustainability. Herein, the primary aim of this work is to focus on the enormous potential of using a high voltage electric field to manipulate polymers from synthetic and/or natural sources for the fabrication of different devices based on elementary units, i.e., fibers or particles, with different characteristic sizes—from micro to nanoscale. Firstly, basic principles and working mechanisms will be introduced in order to correlate the effect of selected process parameters (i.e., an applied voltage) on the dimensional features of the structures. Secondly, a comprehensive overview of the recent trends and potential uses of these processes will be proposed for different biomedical and bio-sustainable application areas.

Research on CH4-CO2 reforming over Ni-Fe catalyst enhanced by electric field

CH4-CO2 reforming is an important way to prepare syngas, but it is often difficult to achieve both high conversion rate and low energy consumption at the same time. High-voltage electric fields can provide high-density energy, and it helps to improve the catalytic effect as well as effectively reduce the reaction temperature. Based on the Ni-Fe catalytic supported on active carbon(AC), a high-voltage electric field was added to the reforming system in this paper. The effects of temperature, electric field strength, and catalytic performance of the catalyst were investigated, then the promotion effect of high voltage electric field on the reforming reaction was revealed. The results show that the Ni-Fe/AC catalyst has better catalytic performance than the single-metal component catalyst, and the comparatively best catalytic effect can be achieved with 10% component loading. After adding a 9 mA electric field at 400 °C, the conversion of CH4 increased from almost 0–19.6%, which was 9 times higher than that of 1 mA, and the conversion of CO2 also increased to 29.3%. This indicated that the enhancement of electric field strength could effectively promote the reforming reaction. Finally, according to the catalyst characterization analysis, it is speculated that the electric field can stimulate the AC support to generate a large amount of active substance, which facilitates the entire catalytic process.

Deodorization of sunflower oil by high voltage electric field as a nonthermal method sunflower oil refining by electric field.

In this study, the high voltage electric field (HVEF) method was used for deodorization of sunflower oil to omit drawbacks of an established industrial method including long time, high energy, chemicals and water consumption, loss of bioactive compounds, and formation of some contaminants due to exposure to heat. Response surface methodology (RSM) was employed to find the optimal values of processing parameters. The effects of voltage (5-15kV), clay (0-1%), electrolyte concentration (0-50mM), the number of electrodes (1-5 pairs), and electrodes distance (1-3cm) on the volatile compounds and tocopherols content were investigated by HS-SPME-GC/MS and HPLC, respectively. The optimal processing conditions were determined to be a voltage of 5kV, a distance of 1cm between the electrodes and a number of five pairs of electrodes. The amount of bleaching clay and electrolyte concentration were zero under optimal conditions. The refining process by HVEF removed 32.33% of the volatile compounds from crude sunflower oil, while the industrial refining process reduced the volatile compounds by only 17.78%. Results indicated no change was observed in the tocopherols content of refined sunflower oil by HVEF method. Based on PCA results, HVEF-treated sample not only contained the lowest concentration of volatile compounds but also was the most similar to crude sample in terms of volatile compounds composition. PRACTICAL APPLICATION: The oil refining process consists of four main stages, the last of which is deodorization. This step involves injecting steam at a temperature of about 240°C, under vacuum for about 50 min. High voltage electric field (HVEF) was able to reduce the number of volatile compounds, while no change was made in the tocopherol content of sunflower oil samples. It also does not form contaminant such as 3-monochloropropane-1,2-diol fatty acid esters and glycidyl fatty acid esters. There is no need to apply the vacuum in HVEF refining, which reduces the production cost and makes the process flow straightforward as well as rapid. This research helps to propagate green refining procedures of vegetable oils in food plants.

Substantially Improved Electrofusion Efficiency of Hybridoma Cells: Based on the Combination of Nanosecond and Microsecond Pulses.

As the initial antibody technology, the preparation of hybridoma cells has been widely used in discovering antibody drugs and is still in use. Various antibody drugs obtained through this technology have been approved for treating human diseases. However, the key to producing hybridoma cells is efficient cell fusion. High-voltage microsecond pulsed electric fields (μsHVPEFs) are currently one of the most common methods used for cell electrofusion. Nevertheless, the membrane potential induced by the external microsecond pulse is proportional to the diameter of the cell, making it difficult to fuse cells of different sizes. Although nanosecond pulsed electric fields (nsPEFs) can achieve the fusion of cells of different sizes, due to the limitation of pore size, deoxyribonucleic acid (DNA) cannot efficiently pass through the cell pores produced by nsPEFs. This directly causes the significant loss of the target gene and reduces the proportion of positive cells after fusion. To achieve an electric field environment independent of cell size and enable efficient cell fusion, we propose a combination of nanosecond pulsed electric fields and low-voltage microsecond pulsed electric fields (ns/μsLVPEFs) to balance the advantages and disadvantages of the two techniques. The results of fluorescence experiments and hybridoma culture experiments showed that after lymphocytes and myeloma cells were stimulated by a pulse (ns/μsLVPEF, μsHVPEF, and control), compared with μsHVPEF, applying ns/μsLVPEF at the same energy could increase the cell fusion efficiency by 1.5–3.0 times. Thus far, we have combined nanosecond and microsecond pulses and provided a practical solution that can significantly increase cell fusion efficiency. This efficient cell fusion method may contribute to the further development of hybridoma technology in electrofusion.

Effect of Negative High-Voltage Corona Field on Hydrophilicity and Vigor of Astragalus mongolicus Seeds

This work aims to study the effect of dc negative high-voltage corona electric field on the vigor and hydrophilicity of Astragalus membranceus (Fisch.) Bge. var. mongolicus (Bge.) Hsiao seeds. The ion wind generated by the multipin pole generator at −3, −4, −5, −6, and −7 kV and the electrostatic field acted together. <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${A}$ </tex-math></inline-formula> . mongholicus seeds were exposed to the electric field for 30, 60, and 90 min. Results show that the ion wind velocity increases significantly with the increase of applied voltage. Malonaldehyde (MDA), electrical conductivity (EC), and apparent contact angle (APCA) in all treatment groups decreased to different degrees compared with the control samples. MDA, EC, and APCA decreased by 56.28%, 20.89%, and 31%, respectively. The hydrophilicity of seeds treated by negative corona field was improved, and the water absorption of seeds was increased by 1.34 times. Fourier infrared spectroscopy, scanning electron microscopy, and energy dispersive X-ray (EDX) spectroscopy were used to examine the spectra, apparent morphology, and surface elements of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${A}$ </tex-math></inline-formula> . mongholicus seed coats from different treatment groups. Results showed that the ionic wind generated by the negative high-voltage corona electric field had a significant etching effect on the seed coat and enhanced the water absorption and fiber strength of hydrophilic functional groups of the seed coat.

Novel assistive technologies for efficient freezing of pork based on high voltage electric field and static magnetic field: A comparative study

To enhance the freezing rate and thawed product quality of pork tenderloin, an experimental study was conducted using the high voltage electric field and static magnetic field separately during freezing. Pork tenderloin pieces were frozen at −20 °C under several high voltage electric fields (10 kV/m (HVEF1), 30 kV/m (HVEF3), 50 kV/m (HVEF5)) and magnetic fields of 2 mT (MF2), 4 mT (MF4), 6 mT (MF6) and 8 mT (MF8). The effects of different methods on freezing rate, ice crystal size as well as the distribution, and product quality after thawing were investigated. The freezing time of pork tenderloin was reduced by 40.04% and 37.81% respectively, under the optimal electric and magnetic field conditions tested. The thawing loss decreased from 5.7% of conventional freezing to 1.7% of HVEF1 and 2.4% of MF2, respectively. In addition, both high-voltage electric field freezing and magnetic field freezing can better maintain the moisture state in the sample. The results for color and pH confirmed that the thawed product quality using HVEF1 and MF2 was superior to that obtained under other conditions. The myofibrillar protein in the thawed products obtained from HVEF1 and MF2 treatments was also found to be thermally more stable. It is noteworthy that the HVEF1 treated sample has the highest umami signal and the lowest salty signal. Considering the enhanced freezing efficiency and improved quality, application of HVEF1 is recommended as a viable strategy to produce high-quality frozen pork tenderloin. Industrial relevanceThe slow freezing rate of frozen meat products and serious deterioration of product quality are the key problems. Therefore, improving the efficiency of freezing is desirable. This study provides ideas for pork preservation. It caters to the need of industrial production of meat product where better efficiency freezing process is highly desirable, and the findings of this study is beneficial to the meat processing industry.

Achieving excellent photocatalytic degradation of pollutants by flower-like SrBi4Ti4O15/BiOCl heterojunction: The promotion of piezoelectric effect

Combining photocatalyst with piezoelectric materials is an effective way to promote the performance of photocatalysis. Herein, a flower-like SrBi4Ti4O15/BiOCl composite is proposed and its photocatalytic degradation performance is effectively improved by piezoelectric effect. SrBi4Ti4O15/BiOCl heterojunction is prepared by molten salt method and hydrothermal method, and the polarization is carried out under the action of direct current high voltage electric field. Piezoelectric effect offers a built-in polarization field for improving the separation efficiency of photogenerated electrons and holes. Hence, under the synergistic action of ultrasound and light, the degradation rate constant of polarized SrBi4Ti4O15/BiOCl to RhB dye reaches 0.7313 min−1, which is 13.13 and 2.53 times that of pure SrBi4Ti4O15 and SrBi4Ti4O15/BiOCl under light only, exceeding almost vast majority piezo-photocatalysts reported. This study provides an efficient and feasible piezo-photocatalyst for pollutant treatment, and contributing to comprehending the mechanism of piezoelectric effect to improve the photocatalytic performance.

Comparison of Presowing Wheat Treatments by Low-Temperature Plasma, Electric Field, Cold Hardening, and Action of Tebuconazole-Based Disinfectant

This work compares the presowing treatment of winter wheat seeds with a low-temperature plasma, a constant high-voltage electric field, a plant protection disinfectant, and cold hardening on the resistance of seedlings to freezing and their morphophysiological characteristics at the initial stage of germination. Various treatment combinations were considered, including the effect of the disinfectant jointly with low-temperature plasma treatment. The greatest stimulating effect from the point of view of seedlings’ morphophysiological characteristics was achieved when seeds were cold-hardened. The action of low-temperature plasma is noticeable up to the third day of germination. The treatment with the low-temperature plasma of seeds pretreated and not-pretreated with the disinfectant had a similar effect on the morphophysiological characteristics of seedlings. The plasma treatment and the electric field were combined with each other, i.e., the plasma treatment effects were added to the electric field effects. Resistance to low temperatures was increased with the hardening of seeds treated with the electric field and the disinfectant. Resistance to low temperatures was reduced when treated with the electric field and/or low-temperature plasma after being treated with the disinfectant.