Mutagenic Effect during Combined Exposure to Ionizing and Non-Ionizing Electromagnetic Radiation.

Using the method of dominant lethal mutations, we assessed the frequency of the death of Drosophila melanogaster embryos under combined exposure to ionizing γ-radiation and non-ionizing pulsed magnetic field at various doses and modes of exposure. Mutagenic effect of combined exposure is antagonistic in nature. The antagonism is more pronounced when the following mode of exposure was used: exposure to non-ionizing pulsed magnetic field for 5 h followed by exposure to γ-radiation at doses of 3, 10, and 60 Gy. In case of reverse sequence of exposures, the antagonistic effect was statistically significant after exposure to γ-radiation at doses of 3 and 10 Gy, whereas at a dose of 20 Gy, a synergistic interaction was noted.

Rapid label-free impedimetric detection of progesterone enhanced by immunomagnetic bead-based competitive immunoreaction.

Detecting progesterone (P4) concentration in cow serum is essential for monitoring the pregnancy progress after fertilization and is significant for the dairy farming industry and veterinary medicine. This study reports enzyme-free immunomagnetic beads (IMBs)-based competitive immunoassay for detecting P4 by P4-bovine serum albumin (BSA)-modified biosensors. The anti-P4 antibody-conjugated IMBs serve as collectors to capture P4 in undiluted serum samples to prevent the biosensor surface from biosample contamination and as insulated labels to report the electron-transfer resistance signal of electrochemical impedance spectroscopy (EIS) measurement. The IMBs and P4-containing samples were mixed for 15-30 min, capable of obtaining stable P4@IMB complexes. The 0.2-kGauss pulsed magnetic field (PMF) of the 20-s pulse width and 20-s relaxation time applied for 5 min can shorten the immunoreaction time between the P4@IMBs and the P4-BSA-modified biosensor and reduce the IMB's nonspecific adsorption on the biosensor surface. This competitive immunoassay's cut-off value and detection limit were 7.71 ng/mL and 7.33 ng/mL, respectively, which is lower than the serum's P4 plateau concentration (over 8 ng/mL) of dairy cows on days 6-16 of estrus cycles and that in pregnancy. The IMB-based immunoassay combining the PMF attraction and the label-free EIS measurement exhibits promising potential for rapidly detecting P4 in undiluted serum.

Feature Matching of Microsecond-Pulsed Magnetic Fields Combined with Fe3O4 Particles for Killing A375 Melanoma Cells.

The combination of magnetic fields and magnetic nanoparticles (MNPs) to kill cancer cells by magneto-mechanical force represents a novel therapy, offering advantages such as non-invasiveness, among others. Pulsed magnetic fields (PMFs) hold promise for application in this therapy due to advantages such as easily adjustable parameters; however, they suffer from the drawback of narrow pulse width. In order to fully exploit the potential of PMFs and MNPs in this therapy, while maximizing therapeutic efficacy within the constraints of the narrow pulse width, a feature-matching theory is proposed, encompassing the matching of three aspects: (1) MNP volume and critical volume of Brownian relaxation, (2) relaxation time and pulse width, and (3) MNP shape and the intermittence of PMF. In the theory, a microsecond-PMF generator was developed, and four kinds of MNPs were selected for in vitro cell experiments. The results demonstrate that the killing rate of the experimental group meeting the requirements of the theory is at least 18% higher than the control group. This validates the accuracy of our theory and provides valuable guidance for the further application of PMFs in this therapy.

Design and Validation of Miniaturized Repetitive Transcranial Magnetic Stimulation (rTMS) Head Coils.

Repetitive transcranial magnetic stimulation (rTMS) is a rapidly developing therapeutic modality for the safe and effective treatment of neuropsychiatric disorders. However, clinical rTMS driving systems and head coils are large, heavy, and expensive, so miniaturized, affordable rTMS devices may facilitate treatment access for patients at home, in underserved areas, in field and mobile hospitals, on ships and submarines, and in space. The central component of a portable rTMS system is a miniaturized, lightweight coil. Such a coil, when mated to lightweight driving circuits, must be able to induce B and E fields of sufficient intensity for medical use. This paper newly identifies and validates salient theoretical considerations specific to the dimensional scaling and miniaturization of coil geometries, particularly figure-8 coils, and delineates novel, key design criteria. In this context, the essential requirement of matching coil inductance with the characteristic resistance of the driver switches is highlighted. Computer simulations predicted E- and B-fields which were validated via benchtop experiments. Using a miniaturized coil with dimensions of 76 mm × 38 mm and weighing only 12.6 g, the peak E-field was 87 V/m at a distance of 1.5 cm. Practical considerations limited the maximum voltage and current to 350 V and 3.1 kA, respectively; nonetheless, this peak E-field value was well within the intensity range, 60-120 V/m, generally held to be therapeutically relevant. The presented parameters and results delineate coil and circuit guidelines for a future miniaturized, power-scalable rTMS system able to generate pulsed E-fields of sufficient amplitude for potential clinical use.

Passive Electrical Components Based on Cotton Fabric Decorated with Iron Oxides Microfibers: The Influence of Static and Pulsed Magnetic Fields on the Equivalent Electrical Properties.

In this work, environmentally friendly and low-cost passive electrical components (PECs) are manufactured based on composites consisting of cotton fabrics soaked with solutions of silicone oil and different amounts of iron oxides microfibers (µFe). The µFe consists of a mixture of three phases: hematite (α-Fe2O3), maghemite (γ-Fe2O3), and magnetite (Fe3O4). The equivalent electrical capacitance (Cp) and resistance (Rp) of PECs are measured as a function of magnetic flux density B in a static and pulsed magnetic field superimposed on an alternating electric field of frequency 1 kHz. The relative variation in the hysteresis curves for both Cp and Rp are obtained by measuring them in the ascending and then the descending mode of B. We show that all these three quantities are sensibly influenced by the volume fractions of µFe and by the values of B. The main influence on this behavior is attributed to the semiconductor properties of the α-Fe2O3 and γ-Fe2O3 components of the oxide microfibers. In addition, it is found that at B≃ 175 mT, the maximum relative variance of the hysteresis curve is about 3.35% for Cp and 3.18 % for Rp. When a pulsed magnetic field is used, it is shown that Cp and Rp closely follow the variation in the magnetic field. Thus, the resulting electrical properties of PECs, together with the fast response to the application of pulsed magnetic fields, make them useful in the fabrication of various devices, such as electric, magnetic, and deformation fields, or mechanical stress sensors with applications in protection against electromagnetic smog, healthcare monitoring, or for human-machine interfacing.

Magnetoresistance and Magnetic Relaxation of La-Sr-Mn-O Films Grown on Si/SiO2 Substrate by Pulsed Injection MOCVD.

The results of magnetoresistance (MR) and resistance relaxation of nanostructured La1-xSrxMnyO3 (LSMO) films with different film thicknesses (60-480 nm) grown on Si/SiO2 substrate by the pulsed-injection MOCVD technique are presented and compared with the reference manganite LSMO/Al2O3 films of the same thickness. The MR was investigated in permanent (up to 0.7 T) and pulsed (up to 10 T) magnetic fields in the temperature range of 80-300 K, and the resistance-relaxation processes were studied after the switch-off of the magnetic pulse with an amplitude of 10 T and a duration of 200 µs. It was found that the high-field MR values were comparable for all investigated films (~-40% at 10 T), whereas the memory effects differed depending on the film thickness and substrate used for the deposition. It was demonstrated that resistance relaxation to the initial state after removal of the magnetic field occurred in two time scales: fast' (~300 µs) and slow (longer than 10 ms). The observed fast relaxation process was analyzed using the Kolmogorov-Avrami-Fatuzzo model, taking into account the reorientation of magnetic domains into their equilibrium state. The smallest remnant resistivity values were found for the LSMO films grown on SiO2/Si substrate in comparison to the LSMO/Al2O3 films. The testing of the LSMO/SiO2/Si-based magnetic sensors in an alternating magnetic field with a half-period of 22 µs demonstrated that these films could be used for the development of fast magnetic sensors operating at room temperature. For operation at cryogenic temperature, the LSMO/SiO2/Si films could be employed only for single-pulse measurements due to magnetic-memory effects.

Combined Pulsed Magnetic Field and Radiofrequency Electromagnetic Field Enhances MMP-9, Collagen-4, VEGF Synthesis to Improve Wound Healing Via Hif-1α/eNOS Pathway.

BACKGROUND: The blood supply of the tissue is very important in the acceleration of wound healing. Radiofrequency electromagnetic field (RF) and the pulsed magnetic field (PMF) increase vasodilation to contribute wound healing. The aim of this study was to evaluate the effects of RF and PMF on wound healing via hypoxia-inducible factor-1 alpha (Hif-1α)/endothelial nitric oxide synthase (eNOS) pathway. METHODS: Forty-eight rats were divided into 4 groups as sham (wound created only), PMF (27.12 MHz, 12 times a day at 30-min intervals), RF (0.5 mT, continuously) and PMF + RF groups. Wounds were created at 1.5 × 1.5 cm size to the dorsal region, and animals were put into unit. Six animals were killed on days 4 and 7; wound tissues were collected for histopathological, immunohistochemical as collagen-4, cytokeratin, matrix metalloproteinase-9 (MMP-9), vascular endothelial growth factor (VEGF) staining and Hif-1α/eNOS/VEGF expressions. RESULTS: On day 4, in addition to increasing VEGF and MMP-9 stainings, connection between intact tissue and scar tissue which was stronger in the RF- and PMF-applied groups was observed. On day 7, epithelization started; inflammatory reaction decreased; collagen production, cytokeratin, VEGF and MMP-9 expression enhanced, especially in the RF + PMF applied group. eNOS, Hif-1α and VEGF expression levels were found to be significantly highest in both days of RF + PMF-applied group. CONCLUSIONS: This study revealed that both in vitro RF and PMF applications can cause notable changes in factors that are required for tissue repair on wound healing such as epithelization, connective tissue formation, collagen production and angiogenesis via vasodilatory Hif-1α/eNOS pathway and VEGF signaling. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Mutation Effect of Ionizing and Non-Ionizing Electromagnetic Radiation on Drosophila melanogaster.

The frequency of D. melanogaster embryonic death was estimated using the method of dominant lethal mutations after exposure to ionizing γ-radiation and non-ionizing pulsed magnetic field. γ-Radiation had a dose-dependent mutational effect on D. melanogaster. A pronounced increase in embryonic death was observed starting from a dose of 3 Gy and reaches a plateau at 60 Gy due to the maximum death of eggs. When D. melanogaster was exposed to pulsed magnetic field, the effect did not depend on the exposure time; a statistically significant genotoxic effect was detected after 5-h exposure.

Cognitive improvement via a modulated rhythmic pulsed magnetic field in D-galactose-induced accelerated aging mice.

Rhythmic physical stimulations have emerged as effective noninvasive intervention strategies in the treatment of pathological cognitive deficits. Transcranial magnetic stimulation (TMS) can regulate neural firing and improve the learning and memory abilities of rodents or patients with cognitive deterioration. However, the effects of elaborate magnetic stimulation with low intensity during aging or other neurological disordering processes on cognitive decline remain unclear. In this study, we developed an elaborate modulated pulsed magnetic field (PMF) stimulation with a complex pattern in the theta repeated frequency and gamma carrier frequency and then determined the effects of this rhythmic PMF on the cognitive function of accelerated aging mice established by chronic subcutaneous injection of D-galactose (D-gal). The results of the Morris water maze (MWM) test showed that mice treated with modulated PMF displayed shorter swimming distance and latency time in the spatial exploration acquisition trial and exhibited a significant preference in the target presumptive platform area in the probe trial, all of which indicated the enhancement in spatial learning and memory abilities upon PMF stimulation of the accelerated aging mice. The novel object recognition (NOR) test results showed a similar tendency as the MWM results although without statistical significance. Further determination of histological structures demonstrated that the cognitive function-related hippocampal CA3 neurons degenerated upon D-gal injection, which could also be partially rescued by PMF application. In comparison with the high-intensity TMS approach, low-intensity magnetic stimulation could be much safer and allow deeper penetration without adverse effects such as seizure. In summary, modulated PMF, even with low intensity, could effectively improve rodent cognitive functions impaired by D-gal-induced accelerated aging, which might provide a new safe therapeutic strategy for cognitive deficits as well as other neurological disorders.

Measurement System for Short-Pulsed Magnetic Fields.

A measurement system based on the colossal magnetoresistance CMR-B-scalar sensor was developed for the measurement of short-duration high-amplitude magnetic fields. The system consists of a magnetic field sensor made from thin nanostructured manganite film with minimized memory effect, and a magnetic field recording module. The memory effect of the La1-xSrx(Mn1-yCoy)zO3 manganite films doped with different amounts of Co and Mn was investigated by measuring the magnetoresistance (MR) and resistance relaxation in pulsed magnetic fields up to 20 T in the temperature range of 80-365 K. It was found that for low-temperature applications, films doped with Co (LSMCO) are preferable due to the minimized magnetic memory effect at these temperatures, compared with LSMO films without Co. For applications at temperatures higher than room temperature, nanostructured manganite LSMO films with increased Mn content above the stoichiometric level have to be used. These films do not exhibit magnetic memory effects and have higher MR values. To avoid parasitic signal due to electromotive forces appearing in the transmission line of the sensor during measurement of short-pulsed magnetic fields, a bipolar-pulsed voltage supply for the sensor was used. For signal recording, a measurement module consisting of a pulsed voltage generator with a frequency up to 12.5 MHz, a 16-bit ADC with a sampling rate of 25 MHz, and a microprocessor was proposed. The circuit of the measurement module was shielded against low- and high-frequency electromagnetic noise, and the recorded signal was transmitted to a personal computer using a fiber optic link. The system was tested using magnetic field generators, generating magnetic fields with pulse durations ranging from 3 to 20 µs. The developed magnetic field measurement system can be used for the measurement of high-pulsed magnetic fields with pulse durations in the order of microseconds in different fields of science and industry.

Genomic DNA damage induced by co-exposure to DNA damaging agents and pulsed magnetic field.

PURPOSE: Many articles describe the effects of extremely low-frequency magnetic fields (MFs) on DNA damage induction. However, the mechanism of MF interaction with living matter is not yet known with certainty. Some works suggest that MF could induce an increase in the efficacy of reactive oxygen species (ROS) production. This work investigates whether pulsed MF exposure produces alterations in genomic DNA damage induced by co-exposure to DNA damaging agents (bleomycin and methyl methanesulfonate (MMS)). MATERIALS AND METHODS: Genomic DNA, prepared from S. cerevisiae cultures, was exposed to pulsed MF (1.5 mT peak, 25 Hz) and MMS (0-1%) (15-60 min), and to MF and bleomycin (0-0.6 IU/mL) (24-72 h). The damage induced to DNA was evaluated by electrophoresis and image analysis. RESULTS: Pulsed MF induced an increment in the level of DNA damage produced by MMS and bleomycin in all groups at the exposure conditions assayed. CONCLUSIONS: Pulsed MF could modulate the cytotoxic action of MMS and bleomycin. The observed effect could be the result of a multifactorial process influenced by the type of agent that damages DNA, the dose, and the duration of the exposure to the pulsed MF.

Precise manipulation of the charge percolation networks of flow-electrode capacitive deionization using a pulsed magnetic field.

Magnetic field is a simple and powerful means that enables controlled the transport of electrode particles in flow electrode capacitive deionization (FCDI). However, the magnetic particles are easily stripped from hybrid suspension electrodes and the precise manipulation of the charge percolation network remains challenging. In this study, a programmable magnetic field was introduced into the FCDI system to enhance the desalination performance and operational stability of magnetic FCDI, with core-shell magnetic carbon (MC) used as an alternative electrode additive. The results showed that the pulsed magnetic field (PMF) was more effective in enhancing the average salt removal rate (ASRR) compared to the constant magnetic field (CMF), with 51.6% and 67.7% enhancement, respectively, compared to the magnetic field-free condition. The outstanding advantage of the PMF lies in the enhancement in the trapping and mediating effects in the switching magnetic field, which keeps the concentration of the electrode particles near the current collector at a high level and greatly facilitates electron transport. In long-term operation (20,000 cycles), the pulsed magnetic FCDI achieved a stable desalinating rate of 0.4-0.68 µmol min-1 cm-2 and a charge efficiency of >96%. In brief, our study introduces a new approach for the precise manipulation of charge percolation networks of the suspension electrodes and provides insight into the charging mechanism of the magnetic FCDI.

Theory and Practice of Using Pulsed Electromagnetic Processing of Metal Melts.

In industrial practice, various methods of external influences on metal melts are used. For example, vibration processing, exposure to ultrasound, and other physical fields. The main purpose of such influences is purposeful grinding of the metal structure, which contributes to the improvement of mechanical characteristics. The article presents an overview of research on pulse processing of ferrous and non-ferrous melts: processing with pulsed current, electromagnetic pulses and pulsed magnetic fields. The results of the analysis showed that, despite the different methods and devices used for these treatments, their effect on the structure and properties of the cast metal is generally the same. The main effect is observed in the refinement of the macro and microstructure and a simultaneous increase in the strength properties and plasticity. The intensity of the observed effects depends on the characteristics of the equipment used to create the pulses. The main characteristics are: pulse duration, pulse frequency, current amplitude, and power.

Pulsed magnetic field treatment ameliorates the progression of peripheral neuropathy by modulating the neuronal oxidative stress, apoptosis and angiogenesis in a rat model of experimental diabetes.

OBJECTIVE: The present study aimed to investigate the possible anti-neuropathic effects of daily pulsed magnetic field treatments (PMF) in streptozotocin (60 mg/kg) induced 4 weeks diabetic (type-1) wistar rats (6-8 months). MATERIALS AND METHODS: Body mass, blood glucose and thermal and mechanical sensations were evaluated during the PMF or sham-PMF in diabetic or non-diabetic rats (n = 7/group). After the measurements of motor nerve conduction velocities (MNCV), the levels of several biomarkers for oxidative stress, apoptosis and angiogenesis in spinal cord and sciatic nerve were measured. RESULTS: PMF for 4 weeks significantly recovered the MCNV (96.9% and 63.9%) and almost fully (100%) restored to the latency and threshold. PMF also significantly suppressed the diabetes induced enhances in biochemical markers of both neuronal tissues. CONCLUSIONS: Findings suggested that PMF might prevent the development of functional abnormalities in diabetic rats due to its anti-oxidative, anti-apoptotic and anti-angiogenic actions in neuronal tissues.

Growth alteration of Allium cepa L. roots exposed to 1.5 mT, 25 Hz pulsed magnetic field.

The response of plants to magnetic fields (MF) is not fully understood. This work studies the effects of pulsed MF on the germination and growth of Allium cepa roots. Onions were exposed to 25Hz, 1.5mT, 33h. Pulsed MF was generated by a Helmholtz-type equipment that generated rectangular voltage pulses. The results showed that fewer roots grew in the specimens exposed to pulsed MF (14±6 roots on day 1 to 21±8 on day 4) than in the control groups (32±17 to 48±23) (p<0.05 Friedman). Control specimens showed a root mean length of 7±4 mm (day 1) and 24±10 mm (day 4). The specimens treated with pulsed MF showed a length of 4±2 mm (day 1), reaching 18±9 mm on day 4 (p<0.001 ANOVA). In conclusion, the exposure of Allium cepa specimens to 25Hz, 1.5mT pulsed MF during 33h produces a decrease in the germination and growth of roots.

[Efficacy and safety of magnet therapy using portable device for knee osteoarthritis. 55-week double-blind study results]. / Effektivnost' i bezopasnost' primeneniya magnitoterapii s pomoshch'yu portativnogo apparata pri lechenii osteoartrita kolennykh sustavov. Rezul'taty dvoinogo slepogo 55-nedel'nogo issledovaniya.

Instrumental physiotherapeutic treatment using portable devices is optimal for patients with rheumatic diseases due to the devices' greater accessibility. However, there are still issues concerning the efficacy of physical factors generated by portable equipment in osteoarthritis (OA), mostly due to the limited evidence. OBJECTIVE: To study the efficacy and safety of long-term use of the portable magnet therapy device ALMAG+ (Almag Active) in knee OA (KOA). MATERIALS AND METHODS: A double-blind, randomized, placebo-controlled, prospective, 55-week clinical trial of the medical device was conducted. The study included patients with primary and secondary (associated with immunoinflammatory rheumatic diseases) KOA stages I-III according to Kellgren-Lawrence diagnosed using generally accepted criteria (R. Altman et al., 1986). Enrollment of patients with secondary KOA was allowed given that the remission or low disease activity was achieved. During the study patients had to receive steady drug therapy. No intra-articular injections of glucocorticosteroids, hyaluronic acid, PRP, and physiotherapy procedures for knees (electrotherapy, shockwave therapy, heat therapy, hydrotherapy, peloid therapy) were allowed three months or less before the enrollment and throughout the study. According to the approved protocol, 77 patients (mean age 52.73±12.97 years) from two research centers participated in the study: 32 (41.6%) were males, and 45 (58.4%) were females. Primary KOA occurred in 41 (52%) patients, 36 (46.8%) patients had secondary KOA (associated with rheumatoid arthritis, ankylosing spondylitis, Sjögren's disease, psoriatic arthritis, systemic lupus erythematosus, or diffuse scleroderma). All patients received NSAIDs as a concomitant therapy, 24.7% received diacerein, 28.6% received disease-modifying anti-rheumatic drugs, 2.6% received methylprednisolone up to 8 mg/day, and 9% received biologic therapy. After randomization, 40 (52%) patients received placebo treatments (Group 1) and 37 (48%) received active treatments (Group 2). Both groups were comparable in the main parameters. The proportion of smokers was higher in Group 2, but the difference was not statistically significant. During the 55-week follow-up, three courses of 18 daily home magnet therapy procedures each were performed. RESULTS: In both groups, starting from week 5 of the study, an improvement of pain on movement and at rest according to VAS compared to the baseline (p<0.01 at all assessment time points) was observed, which can be explained by a pronounced placebo effect, often observed in OA. The improvement of pain at rest was more prominent in Group 2 vs. Group 1 at Week 21 (p=0.038) and Week 55 (p=0.017) of the study, probably due to the anti-inflammatory effect. The overall WOMAC index score was also lower in Group 2 vs. Group 1 at Weeks 21 and 55 (p=0.03 at both time points). The mean articular cartilage thickness, determined by ultrasound, reduced in Group 1 and remained practically unchanged in Group 2 (p=0.011). No adverse events associated with the use of the ALMAG+ (Almag Active) device, according to the attending physician, and no exacerbations of immunoinflammatory rheumatic diseases during the study period were reported. CONCLUSION: The results of a double-blind, placebo-controlled study of magnet therapy using a portable device demonstrated analgesic, anti-inflammatory, and structure-modifying effects of this type of physiotherapeutic treatment. No adverse events and exacerbations of rheumatic diseases associated with the study treatment have been reported.

Neuroprotective and anti-neuropathic actions of pulsed magnetic fields with low frequencies in rats with chronic peripheral neuropathic pain.

The management of chronic peripheral neuropathic pain conditions with conventional treatments is still limited. In this present study, we aimed to determine the anti-neuropathic actions of pulsed magnetic field (PMF) treatments as a therapeutic. Effects of daily PMF treatments for 4 weeks were investigated by examining pain behaviors, hyperalgesia and allodynia, electrophysiological parameters, amplitude of compound action potential (CAP) and sciatic nerve conduction velocity (SNCV) and histopathological changes in rats with chronic constriction injury (CCI). Peripheral and central pro-inflammatory cytokines (TNF α, IL-1ß and IL-17), chemokines (CCL3 and CXCL1) and angiogenic factors (VEGF and bFGF) in sciatic nerves and spinal cord tissues were also measured for determining the possible molecular action mechanisms of PMF treatment. Hyperalgesia and allodynia were observed at the first week and lasted for 4 weeks after CCI. PMF treatments caused time-dependent anti-hyperalgesic and anti-allodynic effects. PMF treatment alleviated the histopathological consequences of CCI on sciatic nerve and significantly improved the amplitude of the CAP and SNCV. PMF treatment inhibited the pro-inflammatory molecules and promoted the anti-inflammatory cytokines in neural tissues. PMF treatment also suppressed the VEGF levels and enhanced the bFGF levels in both neural tissues. The results of the present study suggested that daily PMF treatment may have neuroprotective and anti-neuropathic pain actions in rats with CCI-induced neuropathy due to its modulating effects on neuro-inflammatory and neuro-angiogenic mediators in central and peripheral neural tissues.

Impact of pulsed magnetic field treatment on enzymatic inactivation and quality of cloudy apple juice.

The effects of PMF (5-7 T, 5-30 pulses) on enzyme activity, pH, titratable acidity, soluble solids, color, ascorbic acid, total phenols and antioxidant activity (DPPH radical scavenging activity) of cloudy apple juice were evaluated. PMF inhibited activities of polyphenoloxidase (PPO), peroxidase (POD) and pectinmethylesterase (PME), but PPO was more sensitive to PMF than POD and PME. At the intensity of 6 T with 15 pulses, PPO and POD both exhibited the lowest residual activity (53.22 and 92.96%), while PME showed the lowest residual activity (83.01%) at 7 T with 30 pulses. No significant effect on soluble solids was found under all processing parameters, whereas significant decreases of ascorbic acid were observed at the intensity of 7 T with 5-30 pulses. PMF did not change pH, titratable acidity, color, total phenols and DPPH radical scavenging activity severely. These results suggest PMF can be a potential technology for enzymatic inactivation in apple juice with high retention of quality.

Unveiling the induced lipid production in Chlorella vulgaris under pulsed magnetic field treatment.

The pulsed magnetic field (PMF) was adopted for the enhancement of lipid in Chlorella vulgaris. The average biomass and lipid content in outdoor conditions were found to be 0.315 g.L-1 and 20-25% respectively. The effect of magnetic flux density in the range of 600-900 mG on biomass production and lipid content was studied. A magnetic flux density of 700 mG at 1Hz for 4 h per day was found to be optimum, which yielded a maximum dry cell weight of 0.61 g.L-1, two-fold than the normal condition, with a lipid content of 55.2%. FTIR analysis evidenced that the PMF treatment increased the active oxygen, which could be attributed to the enhancement of growth and lipid of C. vulgaris.

Viability inhibition of A375 melanoma cellsin vitroby a high-frequency nanosecond-pulsed magnetic field combined with targeted iron oxide nanoparticles via membrane magnetoporation.

Poor efficacy and low electrical safety are issues in the treatment of tumours with pulsed magnetic fields (PMFs). Based on the cumulative effect of high-frequency pulses and the enhanced perforation effect of targeted nanoparticles, this article proposes for the first time a new method that combines high-frequency nanosecond-pulsed magnetic fields (nsPMFs) with folic acid-superparamagnetic iron oxide nanoparticles (SPIONs-FA) to kill tumour cells. After determining the safe concentration of the targeted iron oxide nanoparticles, CCK-8 reagent was used to detect the changes in cell viability after utilising the combined method. After that, PI macromolecular dyes were used to stain the cells. Then, the state of the cell membrane was observed by scanning electron microscopy, and other methods were applied to study the cell membrane permeability changes after the combined treatment of the cells. It was finally confirmed that the high-frequency PMF can significantly reduce cell viability through the cumulative effect. In addition, the targeted iron oxide nanoparticles can reduce the magnetic field amplitude and the number of pulses required for the high-frequency PMF to kill tumour cellsin vitrothrough magnetoporation. The objective of this research is to improve the electrical safety of the PMF with the use of nsPMFs for the safe, efficient and low-intensity treatment of tumours.