Combination Of Electromagnetic Fields Research Articles

Hyper- and Hypopigmentation in a Subject with Fitzpatrick Skin Phototype VI: A New Treatment Option.

Background: Laser therapies can cause hyper- and hypopigmentation of the skin. There is little evidence in the literature of effective treatments for these types of problems in Fitzpatrick skin phototypes IV-VI. The main aim of this retrospective study is to evaluate the effects of a new therapy that combines the application of electromagnetic fields and vacuum on a subject with Fitzpatrick skin phototype VI, who presented extensive, laser-induced facial dyschromia. The secondary aim is to test the effectiveness of a free imaging software for assessing skin pigmentation. Methods: The level of improvement after therapy was evaluated, with a 5-point Likert scale, one month after the end of the treatment by the subject and by the doctor who performed the treatment, and by two blinded dermatologists. With the free software, a three-dimensional reconstruction of the treated area and the evaluation of the color distribution were performed. Results: Both the subject and the doctors involved in the study positively evaluated the effects of the treatment. The image analysis highlighted the homogenization of the skin color in the treated area. Conclusions: The combination of electromagnetic fields and vacuum for dyschromia treatments appears promising. The new method of assessing melanin levels resulted particularly efficient.

Combination of electromagnetic field and harris hawks optimization algorithms with optimization to optimization structure and its application for optimum power flow

ABSTRACT Electromagnetic Field Optimization (EFO) and Harris Hawk Optimization (HHO) algorithms are combined with the optimization to optimization (OtoO) approach, and the EFO-HHO algorithm pair is presented in this study. EFO method was used as the essential algorithm and HHO method was used as the auxiliary algorithm according to the OtoO structure. The constant parameters (R_rate, Ps_rate, P_field, N_field) of the EFO algorithm that affect the optimization performance are optimized with the HHO optimization algorithm for the related optimization problem. The proposed method was tested on 10 different benchmark functions according to different dimensional (30, 50100). The EFO-HHO algorithm pair can produce better results than the existing literature, especially in cases of increased dimension with the proposed approach. In addition to these, the OPF problem was tested on the IEEE 30 test bus system for the engineering application of the proposed method. The results are compared with the existing literature results. As it can be seen from the results, it has been shown on the real engineering problem that the optimization performance can be increased with the OtoO approach without changing the basic philosophy of the EFO algorithm.

Externally Applied Electromagnetic Fields and Hyperthermia Irreversibly Damage Cancer Cells

At present, the applications and efficacy of non-ionizing radiations (NIR) in oncotherapy are limited. In terms of potential combinations, the use of biocompatible magnetic nanoparticles as heat mediators has been extensively investigated. Nevertheless, developing more efficient heat nanomediators that may exhibit high specific absorption rates is still an unsolved problem. Our aim was to investigate if externally applied magnetic fields and a heat-inducing NIR affect tumor cell viability. To this end, under in vitro conditions, different human cancer cells (A2058 melanoma, AsPC1 pancreas carcinoma, MDA-MB-231 breast carcinoma) were treated with the combination of electromagnetic fields (EMFs, using solenoids) and hyperthermia (HT, using a thermostated bath). The effect of NIR was also studied in combination with standard chemotherapy and targeted therapy. An experimental device combining EMFs and high-intensity focused ultrasounds (HIFU)-induced HT was tested in vivo. EMFs (25 µT, 4 h) or HT (52 °C, 40 min) showed a limited effect on cancer cell viability in vitro. However, their combination decreased viability to approximately 16%, 50%, and 21% of control values in A2058, AsPC1, and MDA-MB-231 cells, respectively. Increased lysosomal permeability, release of cathepsins into the cytosol, and mitochondria-dependent activation of cell death are the underlying mechanisms. Cancer cells could be completely eliminated by combining EMFs, HT, and standard chemotherapy or EMFs, HT, and anti-Hsp70-targeted therapy. As a proof of concept, in vivo experiments performed in AsPC1 xenografts showed that a combination of EMFs, HIFU-induced HT, standard chemotherapy, and a lysosomal permeabilizer induces a complete cancer regression.

Energetics and Kinetics of Plant Raw Material Dehydration Processes

The aim of this work is the energy-efficient equipment creation for production of a highquality dry product from a plant raw material and development of scientific and engineering foundation for the design of such an equipment. The achievement of this aim lies in a deep analysis of tendency in the development of a drying theory and technique. The graph is presented, on the basis of which the development of heat and moisture transfer model of A.V. Lykov is given, taking into account the P. A. Rebinder moisture bond forms specificity. The problems of convective drying modern technologies are determined; the reasons of high-energy consumption during their work are substantiated. The electrodynamic dehydrators classification is given, which consideres the combined simple modes (drying) and hybrid dehydration modes. On the basis of the first law of thermodynamics, the possibility of a significant decrease in energy consumption is shown by the organization of a “vapordynamic” effect. The most significant result of the work is the construction of the electrodynamic apparatus module for dehydration of food and medicinal plant raw material. By the combination of electromagnetic field with the filtration process the specific energy consumptions were 1.9 MJ per 1 kg of the removed moisture, at the hybrid processes — juice yield exceeded vapor yield by 3.5 times. The significance of the work consists in the fact that the scientific conception of the authors on the possibilities of the significant decrease in energy consumption during the raw material dehydration at the innovative electrodynamic type apparatuses was practically proven.

Energetics and Kinetics of Plant Raw Material Dehydration Processes

The aim of this work is the energy-efficient equipment creation for production of a highquality dry product from a plant raw material and development of scientific and engineering foundation for the design of such an equipment. The achievement of this aim lies in a deep analysis of tendency in the development of a drying theory and technique. The graph is presented, on the basis of which the development of heat and moisture transfer model of A.V. Lykov is given, taking into account the P. A. Rebinder moisture bond forms specificity. The problems of convective drying modern technologies are determined; the reasons of high-energy consumption during their work are substantiated. The electrodynamic dehydrators classification is given, which considers the combined simple modes (drying) and hybrid dehydration modes. On the basis of the first law of thermodynamics, the possibility of a significant decrease in energy consumption is shown by the organization of a “vapordynamic” effect. The most significant result of the work is the construction of the electrodynamic apparatus module for dehydration of food and medicinal plant raw material. By the combination of electromagnetic field with the filtration process the specific energy consumptions were 1.9 MJ per 1 kg of the removed moisture, at the hybrid processes — juice yield exceeded vapor yield by 3.5 times. The significance of the work consists in the fact that the scientific conception of the authors on the possibilities of the significant decrease in energy consumption during the raw material dehydration at the innovative electrodynamic type apparatuses was practically proven

Issues on the Electron Stopping Power Modulated by Magnetic and Electric Fields

Ionizing radiation has been employed in conjunction with various clinical modalities for therapeutic purposes. Often, surgery, chemo and radiation therapies have been combined on the arsenal against cancer. Nontraditional techniques, as Tumor Treating Fields (TTF) that uses low-intensity variable electric fields, have also been employed for the treatment of brain tumors, glioblastoma multiforme (GBM), with promising results in reducing the harmful radio and chemotherapy effects, while maintaining the same tumor control rates. The combination of electromagnetic field and chemotherapy has already held a clinical investigation; however, it is missing the experimental and theoretical studies coupling electric and magnetic fields with electron radiotherapy. Herein, a theoretical analysis involving the Stopping Power of electron particles in conjunction with static electric and magnetic fields (E, H) was addressed in order to study the relevance of the use of external electromagnetic fields in radiotherapy. The findings reinforce the possibility of application of the coupling magnetic field with electron radiotherapy, and open a horizon to future experimental and clinical studies if the relevance is enough.

Sinusoidal electromagnetic fields accelerate bone regeneration by boosting the multifunctionality of bone marrow mesenchymal stem cells

BackgroundThe repair of critical-sized bone defects is always a challenging problem. Electromagnetic fields (EMFs), used as a physiotherapy for bone defects, have been suspected to cause potential hazards to human health due to the long-term exposure. To optimize the application of EMF while avoiding its adverse effects, a combination of EMF and tissue engineering techniques is critical. Furthermore, a deeper understanding of the mechanism of action of EMF will lead to better applications in the future.MethodsIn this research, bone marrow mesenchymal stem cells (BMSCs) seeded on 3D-printed scaffolds were treated with sinusoidal EMFs in vitro. Then, 5.5 mm critical-sized calvarial defects were created in rats, and the cell scaffolds were implanted into the defects. In addition, the molecular and cellular mechanisms by which EMFs regulate BMSCs were explored with various approaches to gain deeper insight into the effects of EMFs.ResultsThe cell scaffolds treated with EMF successfully accelerated the repair of critical-sized calvarial defects. Further studies revealed that EMF could not directly induce the differentiation of BMSCs but improved the sensitivity of BMSCs to BMP signals by upregulating the quantity of specific BMP (bone morphogenetic protein) receptors. Once these receptors receive BMP signals from the surrounding milieu, a cascade of reactions is initiated to promote osteogenic differentiation via the BMP/Smad signalling pathway. Moreover, the cytokines secreted by BMSCs treated with EMF can better facilitate angiogenesis and osteoimmunomodulation which play fundamental roles in bone regeneration.ConclusionIn summary, EMF can promote the osteogenic potential of BMSCs and enhance the paracrine function of BMSCs to facilitate bone regeneration. These findings highlight the profound impact of EMF on tissue engineering and provide a new strategy for the clinical treatment of bone defects.

Effect of Combined Electromagnetic Fields on Microstructure and Properties of Large-Sized Ingot of 2219 Aluminum Alloy

Large-sized 2219 aluminum alloy ingot has wide application prospect in aerospace and military fields. Severe defects, such as coarse grain, the inhomogeneity of structure and macrosegregation occurred in large-sized aluminum ingot produced by normal DC casting. The application of a single magnetic field in DC casting process cannot solve these defects. In this paper, a new method with the combination of electromagnetic fields imposed on bulk melt treatment during DC casting was proposed. And a φ508 mm ingot of 2219 aluminum alloy was prepared in this method. Compared with the normal DC casting, the effect of the combined electromagnetic fields on the microstructure and properties was studied. The experimental results demonstrate that the application of the combined electromagnetic fields significantly refines the grains, and the grain size distribution on the cross section of the ingot tends to be more uniform as well as the mechanical properties are significantly improved. The microstructure and grain size distribution can be significantly affected by different combined electromagnetic fields. It is considered that the appropriate combined electromagnetic fields parameters play an important role in controlling the homogeneity of large-sized ingots.

Impact of electromagnetic fields on in vitro toxicity of silver and graphene nanoparticles

ABSTRACTThe correlation between shape and concentration of silver nanoparticles (AgNPs), their cytotoxicity and formation of reactive oxygen species (ROS) in the presence of electromagnetic fields (EMFs) has been investigated. In addition, the bio-effects caused by the combination of EMFs and graphene nanoparticles (GrNPs) have been also assessed. The AgNPs of three shapes (triangular, spherical and colloidal) and GrNPs were added in high concentrations to the culture of human fibroblasts and exposed to EMF of three different frequencies: 900, 2400 and 7500 MHz. The results demonstrated the dependence of the EMF-induced cytotoxicity on the shape and concentration of AgNPs. The maximal cell killing effect was observed at 900 MHz frequency for NPs of all shapes and concentrations. The highest temperature elevation was observed for GrNPs solution irradiated by EMF of 900 MHz frequency. The exposure to EMF led to significant increase of ROS formation in triangular and colloidal AgNPs solutions. However, no impact of EMF on ROS production was detected for spherical AgNPs. GrNPs demonstrated ROS-protective activity that was dependent on their concentration. Our findings indicate the feasibility to control cytotoxicity of AgNPs by means of EMFs. The effect EMF on the biological activity of AgNPs and GrNPs is reported here for the first time.

Is magnetic resonance imaging teratogenic during pregnancy? Literature review

Magnetic resonance imaging is a diagnostic tool used for obtaining an image through the combination of electromagnetic fields and radiofrequency. Given its properties and safety, it is the imaging modality of choice in pregnant women. However, little is known about the effects of MRI on the developing foetus. ObjectivesTo identify the effects of the use of magnetic resonance imaging on the foetus when used as a diagnostic tool during pregnancy. Materials and methodsA literature search was performed in PubMed, Embase, and LILACS. Clinical guidelines and the grey literature were also reviewed. An analysis was made based on the findings. ResultsFour potentially adverse effects where found: (1) The impact on the auditory development due to the acoustic sound made by the resonator. (2) Teratogenic effects on DNA. (3) Physical deformities secondary to temperature increase. (4) Teratogenic effects due to the use of gadolinium as a contrast agent. ConclusionThe risk assessment on the use of magnetic resonance imaging on the foetus is complex, owing to the multiple differences in field strength, force gradients, and radiofrequency pulses used. Although the adverse effects of using this method are not very clear, there are studies that describe the possible outcomes that can result from the use of this imaging modality. It is recommended to use MRI with caution, as long as the benefits outweigh the risk in pregnant patients.

¿Es teratogénica la resonancia magnética durante el embarazo? Revisión de la literatura

Magnetic resonance imaging is a diagnostic tool used for obtaining an image through the combination of electromagnetic fields and radiofrequency. Given its properties and safety, it is the imaging modality of choice in pregnant women. However, little is known about the effects of MRI on the developing foetus. ObjectivesTo identify the effects of the use of magnetic resonance imaging on the foetus when used as a diagnostic tool during pregnancy. Materials and methodsA literature search was performed in PubMed, Embase, and LILACS. Clinical guidelines and the grey literature were also reviewed. An analysis was made based on the findings. ResultsFour potentially adverse effects where found: 1) The impact on the auditory development due to the acoustic sound made by the resonator. 2) Teratogenic effects on DNA. 3) Physical deformities secondary to temperature increase. 4) Teratogenic effects due to the use of gadolinium as a contrast agent. ConclusionThe risk assessment on the use of magnetic resonance imaging on the foetus is complex, owing to the multiple differences in field strength, force gradients, and radiofrequency pulses used. Although the adverse effects of using this method are not very clear, there are studies that describe the possible outcomes that can result from the use of this imaging modality. It is recommended to use MRI with caution, as long as the benefits outweigh the risk in pregnant patients.

Combined effects of electromagnetic field and low-level laser increase proliferation and alter the morphology of human adipose tissue-derived mesenchymal stem cells.

In recent years, electromagnetic field (EMF) and low-level laser (LLL) have been found to affect various biological processes, the growth and proliferation of cells, and especially that of stem cells. The aim of this study was to investigate the effects of EMF and LLL on proliferation of human adipose tissue-derived mesenchymal stem cells (hAT-MSCs) and thus to examine the impact of these therapeutic physical modalities on stem cell engraftment. hAT-MSCs were isolated from subcutaneous adipose tissue of six persons ranging in age from 21 to 56years. EMF was applied for a period of 7days, once a day for 30min, via a magnetic cushion surface at a frequency of 50Hz and an intensity of 3mT. LLL was applied also for 7days, once a day for 5min, at radiation energies of 3J/cm2, with a wavelength of 808nm, power output of 200mW, and power density of 0.2W/cm2. Nonexposed cells (control) were cultivated under the same culture conditions. Seven days after treatment, the cells were examined for cell viability, proliferation, and morphology. We found that after 7days, the number of EMF-treated hAT-MSCs was significantly higher than the number of the untreated cells, LLL-treated hAT-MSCs were more numerous than EMF-treated cells, and hAT-MSCs that were treated with the combination of EMF and LLL were the most numerous. EMF and/or LLL treatment did not significantly affect hAT-MSC viability by itself. Changes in cell morphology were also observed, in terms of an increase in cell surface area and fractal dimension in hAT-MSCs treated with EMF and the combination of EMF and LLL. In conclusion, EMF and/or LLL treatment accelerated the proliferation of hAT-MSCs without compromising their viability, and therefore, they may be used in stem cell tissue engineering.

Bio-effects of non-ionizing electromagnetic fields in context of cancer therapy

Bio-effects mediated by non-ionizing electromagnetic fields (EMF) have become a hot topic of research in the last decades. This interest has been triggered by a growing public concern about the rapid expansion of telecommunication devices and possible consequences of their use on human health. Despite a feasibility study of potential negative impacts, the therapeutic advantages of EMF could be effectively harnessed for the treatment of cancer and other diseases. This review aims to examine recent findings relating to the mechanisms of action underlying the bio-effects induced by non-ionizing EMF. The potential of non-thermal and thermal effects is discussed in the context of possible applications for the induction of apoptosis, formation of reactive oxygen species, and increase of membrane permeability in malignant cells. A special emphasis has been put on the combination of EMF with magnetic nano-particles and ultrasound for cancer treatment. The review encompasses both human and animal studies.

Mathematical Modelling of Microwave Pyrolysis

Abstract This study deals with a detailed numerical investigation of the microwave heating process in plastic pyrolysis. The pyrolysis of high-density polyethylene (HDPE) was studied using a single-mode microwave cavity, TE10 mode, at 2.45 GHz with two different absorbents, as carbon and silicon carbide, and the results were compared. The temperature distribution inside the sample was determined by solving the conservation equations coupled with the microwave and chemical kinetic equations. Lambert’s law was applied to describe the electromagnetic field in the microwave cavity. The effective heat capacity method was used to account for the latent heat in the melting range of plastic. The heat of the reaction was taken into account using first-order kinetic equations assuming a single-step reaction. One-dimensional model equations were solved using the finite difference method utilising MATLAB codes. The model developed in this study provides a better understanding of the fundamental mechanisms of the microwave pyrolysis of HDPE based on a combination of electromagnetic field and thermal models. The primary focus was to incorporate and investigate the effect of the phase changes and reaction during microwave pyrolysis. The results show that the temperature profile strongly depends on the physical properties of the material. Silicon carbide provides more uniform heating distribution compared with carbon.

Effect of Acute Extremely Low Frequency Electromagnetic Field Exposure on the Antioxidant Status and Lipid Levels in Rat Brain

It is generally accepted that electromagnetic fields (EMF) can exert biological effects; however, the mechanisms by which EMF elicits responses are still unknown. The present study was designed to assess the immediate effects of acute EMF exposure, movement restriction, and the combination of both on the antioxidant systems and lipid content in the whole brain of rat. Thirty two male Wistar rats were arranged in four groups: control, EMF exposed, movement restrained (MR), and EMF + MR for 2 h. Rats were then sacrificed and their brains analyzed for superoxide dismutase and catalase activities, reduced glutathione, nitric oxide, total cholesterol, and triacylglycerol levels, as well as plasma corticosterone concentrations. Acute exposure to EMF induces reduction in catalase and superoxide dismutase activities, whereas the combination of EMF + MR also decreases both reduced glutathione and nitric oxide levels. Our results show that the acute exposure to EMF does not induce elevation of stress-hormone corticosterone but impairs the antioxidant status in rat brain. Plasma corticosterone concentration and antioxidant data indicate that the acute exposure to EMF appears to be a mild stressor that leads to some adaptive responses due to the activation of systems controlling the brain oxidative balance.

A Position Detection Strategy for Sensorless Surface Mounted Permanent Magnet Motors at Low Speed Using Transient Finite-Element Analysis

A novel solution for sensorless starting of conventional surface mounted PM motors is proposed. The strategy of the proposed scheme is to creatively formulate a combination of electromagnetic field with transient finite element method (FEM). The proposed solution is an improvement over and above conventional methods in that it is based on rotor position detection at zero speed with high frequency signal injection and back EMF detection. Previous researches tend to consider the induced signal from different winding terminals independently. The proposed methodology however exploits the induced voltage signals from two of the motor winding terminals, using the third terminal as the signal injection point. The strategy also eliminates the process of polarity tests. The relationship between the dependency of induced signals and the rotor position angle is summarized, and a simple motor starting scheme is proposed. Effects arising from the transient characteristics of the injected/induced signals are fully addressed using FEM.

900-MHz Microwave Radiation Enhances γ-Ray Adverse Effects on SHG44 Cells

Mobile phones are widely used globally. However, the biological effects due to exposure to electromagnetic fields (EMF) produced by mobile phones are largely unknown. Environmental and occupational exposure of humans to γ-rays is a biologically relevant phenomenon. Consequently studies were undertaken to examine the interactions between γ-rays and EMF on human health. In this study, exposure to 900-MHz EMF expanded γ-ray damage to SHG44 cells. Preexposure EMF enhanced the decrease in cell proliferation induced by γ-ray irradiation and the rate of apoptosis. The combination of EMF and γ-ray exposure resulted in a synergistic effect by triggering stress response, which increased reactive oxygen species, but the expression of hsp70 at both mRNA and protein levels remained unaltered. Data indicate that the adverse effects of γ-rays on cellular functions are strengthened by EMF.

Study of the different responsive behaviour of the sidebands in LIGO I

Gravitational waves may be measured by detecting the length change induced by them in a Fabry–Perot cavity. In order to amplify the effect on the laser beam driving the cavity, the end mirrors are almost totally reflective so that when the resonant conditions are achieved, the electromagnetic field reflected from the cavity only changes in phase when the resonator changes in length. Several techniques may be used for the signal extraction; for example sidebands can be generated by phase modulation of the laser beam, which are minimally sensitive to any length change in the Fabry–Perot cavity when the carrier is resonating in there. Therefore, they can be used as a reference for the measurement of the variation induced by the gravitational wave upon the carrier. In an ideal case they are symmetric around the carrier for an unperturbed configuration. If the symmetry is broken, the combination of electromagnetic fields, which is supposed to be proportional to the gravitational strain, is a non-zero quantity because of a variety of imperfections in the real interferometers. We will discuss the fundamental mechanism beneath this phenomenon that is observed experimentally.

Variation in as cast and aged structures of centrifugally cast heat resistant steel solidified in an electromagnetic field and under different cooling conditions

The influences of an applied electromagnetic field and cooling conditions on the as cast and aged structures of centrifugally cast heat resistant HK40 steel tubes were investigated. The results reveal that both the electromagnetic field and the cooling ability of the casting mould have significant effects on the macrostructure morphology and the volume fraction and distribution of eutectic carbides, as well as on the homogeneity of secondary precipitation caused by high temperature aging treatment. The differences in the structures are attributed to the different solidification processes of the cast tubes. It is indicated that a reasonable combination of electromagnetic field and cooling conditions during solidification is greatly beneficial, leading to an improvement of creep resistance of cast tubes.

Reduction of cogging torque in spindle motors for CD-ROM drive

In this paper an approach to design a low cogging torque spindle motor without skewing stator slots or magnet poles is proposed. The effects of the slot and pole number combination and optimal choice of the width ratio of armature teeth to magnet pole are are investigated. A finite element method based on a combination of electromagnetic field and circuit equations for magnetic field modeling and torque prediction is presented. Results show that increasing the number of the least common multiple of slot and pole gives only sufficient conditions to decrease the level of cogging torque. To obtain smaller amplitude of the cogging torque, it is also necessary to choose the width ratio of armature teeth to magnet pole are properly.