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The paper notes the potential for enhancing seed productivity through exposure to an electromagnetic field. It touches upon both theoretical and practical considerations for developing an experimental laboratory plant for pre-sowing seed treatment using a low-frequency electromagnetic field and aiming to achieve a magnetobiological effect. (Research purpose) The study aims to investigate the influence of low-frequency electromagnetic field on the composition and properties of grain seeds. (Materials and methods) Standard emitters, characterized by a magnetic induction variability of 3-75 millitesla and a radiation frequency of 1-100 Hertz, were employed to ensure the necessary treatment parameters for a batch of seeds. (Results and discussion) The study investigates the impact of magnetization on the germination process, germination energy, and the physical and chemical properties of seeds subjected to different parameters of a low-frequency electromagnetic field (ranging from 3 to 75 millitesla in magnetic induction and a radiation frequency of 10-16 Hertz).The quality of the effect was analyzed with respect to the installation parameters and seed mass, ranging from 10 to 500 grams, across various cereal crops. Subsequently, specific modes were identified, and a functional irradiation program was devised to ensure a highly effective impact on seeds, optimizing their germination, sprouting and development. (Conclusions) The impact of a low-frequency electromagnetic field on the composition and properties of grain has been studied. An experimental laboratory plant with sources of a low-frequency electromagnetic field has been developed and irradiation modes have been justified. The pre-sowing treatment of an industrial batch, the magnetobiological effect is contingent upon several factors, including the crop type and variety, activation of a biological complex in a cell that initiates the development of a seedling, seed quality and moisture content, the presence of microorganisms on the surface, pathogenic ones included, and the characteristics of irradiation sources and energy parameters. The parameters of the low-frequency electromagnetic field were determined as follows: magnetic induction ranging from 3 to 75 millitesla, a frequency 10-16 Hertz, and seed weight varying from 10 to 500 grams. These identified parameters will be applied in the development of an industrial unit designed for the preparation of seed material and enhancement of its sowing properties.

This paper presents the transformation mechanism of a signal from the magnetic component of a low-frequency electromagnetic field with extremely low energy into a chemical and biochemical response in aqueous solutions of nucleic acids and proteins. The developed theoretical model shows that oxidative DNA damage and conformational transitions in proteins are based on a universal mechanism for changing the amount of the most long-lived form, hydrogen peroxide, in a chemical oscillator of mutual transformations of reactive oxygen species under a low-intensity electromagnetic field. It has been experimentally found that the content of hydrogen peroxide in solutions of biopolymers resonantly depends on the frequency of the applied field. Conformational changes in proteins are accompanied by increasing accessibility and activity of the nucleophilic centers, which are potential targets for reactive oxygen species. Complete unfolding and denaturation of the protein amino-acid chain in a low-frequency electromagnetic field did not occur. It has been shown that the enhanced formation of hydrogen peroxide at 3 and 50 Hz leads to oxidative modification of nitrogenous bases in DNA. [ABSTRACT FROM AUTHOR]

Introduction: Low-frequency electromagnetic field (50 Hz) (EMF) can modify crucial neuronal processes. Existing data indicate that exposure to EMF may represent a mild stressor and contribute to disturbances of the hypothalamic-pituitary-adrenal (HPA) axis. The important regulatory pathways controlling HPA axis activity include two types of corticosteroid receptors: mineralocorticoid receptors (MRs) and glucocorticoid receptors. They are particularly abundant in the hippocampus, a key locus of HPA axis feedback control. The research aimed at determining whether (1) EMF exhibits hormesis, it means bidirectional action depending on EMF intensity (1 or 7 mT) and (2) repeated EMF exposure changes stress response to subsequent stress factors. Methods: The exposure (7 days, 1 h/day) of adult rats to EMF (1 mT and 7 mT) was repeated 3 times. HPA axis hormones and their receptors were analysed after each following exposure. Moreover, the impact of EMF exposure on hormonal and behavioural responses to subsequent stress factor – open-field test was evaluated. Results: Our data suggest that exposure to EMF can establish a new "set-point" for HPA axis activity. The direction and dynamics of this process depend on the intensity of EMF and the number of exposures. EMF of 1 mT induced an adaptive stress response, but 7 mT EMF caused sensitization. Consequently, EMF changed the vulnerability of the organism to a subsequent stress factor. We have also shown the increase in MR mRNA abundance in the hippocampus of 1 mT EMF-exposed rats, which can represent the possible neuroprotective response and suggest therapeutic properties of EMFs. [ABSTRACT FROM AUTHOR]

To verify whether a low-frequency electromagnetic field (LFE field) can help reduce structural damage during the freeze–thaw process and maintain shelf life, Mongolian cheese was frozen at −10, −20, and −30 °C, then thawed at microwave or room temperature. Results showed that LFE field-assisted frozen treatment could reduce ice crystal size and protect the protein matrix structure of cheese. Frozen–thawed cheese retained 96.5% of its hardness and showed no significant difference from the fresh one in elasticity, cohesion, and chewiness. Frozen cheese showed similar but slower ripening behavior during storage, suggesting a potential application of the LFE field in the frozen storage of high-protein foods. [ABSTRACT FROM AUTHOR]

It is important to periodically measure, analyze, and map electromagnetic radiation levels due to potential risks. This study aims to draw attention to new electromagnetic pollution caused by radio frequencies and extremely low frequencies. For this reason, electric field and magnetic field measurements were carried out in the 1-Hz–400-kHz frequency band in a shopping mall, where electronic devices cause low-frequency electromagnetic radiation intensively. The measurements were performed with the EHP-50F device for 24 h a day for a week. The measurements were made at 10 points in the shopping mall, and the measurement results were evaluated over five different sectors: electronics, clothing and accessories (male–female), personal care and cosmetics, supermarket, and the playland for children. Magnetic maps of each sector were produced. In addition, the specific absorption rates (SAR) of male and female customers in these workplaces were determined. This is the first study carried out to find SAR caused by low-frequency radiation. Although the safe limit value of SAR for the whole body is 0.08 W/kg, the SAR values calculated in the playland and electronics sectors were obtained to be 0.763 and 0.39 W/kg, respectively. Results clearly demonstrate how especially small children are exposed to danger in the long term. [ABSTRACT FROM AUTHOR]

Featured Application: Results of the presented work could be potentially used as evidence of long-term exposure to low-frequency magnetic field effects on the growth of cell cultures. This article is focused on the in vitro experimental verification of the basic necessary conditions for valid interpretation of an ion parametric resonance prediction model of biological reaction on an externally applied, extremely low-frequency magnetic field. Experiments are performed on model organism Saccharomyces cerevisiae strain BY4741, with the intention to target calcium ions, which already produced interesting preliminary results within authors' previous works, confirming specific magnetic field settings being bioactive. To study the nature and origin of biological reactions more exhaustingly, the research is aimed at two chosen physical aspects of ion parametric resonance theory. In the first part, experiments are set up to verify the resonance point validity for calcium ions and to perform a sensitivity analysis of the biological system response around this point. In the second part, the main attention is paid to the verification of the validity of maximum biological effect at specific BAC/BDC ratios, reflecting the ion parametric resonance theory as well as the current state of the art and knowledge. Both series of experiments have shown interesting results, confirming 29.89 Hz as a bioactive frequency for a BAC/BDC ratio of 1.8. These observations are in close correlation with the assumptions of the ion parametric resonance model for targeting calcium ions. The performed sensitivity analysis around the resonance point looks even more interesting, as conducted preliminary experiments resulted in two more pronounced bioactive frequencies of 24.89 and 34.89 Hz, in terms of biological response significance, than the resonance frequency assumed by an investigated prediction model. The narrow width of the peak, which is typical for physical phenomena of resonant nature, was not observed within this series of experiments, which would be addressed more precisely in future work of authors. [ABSTRACT FROM AUTHOR]

For studying the changes of macro-physical field in the casting process of large-scale rare earth magnesium alloy, through the numerical simulation method, a two-dimensional axisymmetric multi-physical field coupling model was established by using the multi-physical simulation software COMSOL Multiphysics. The changes of temperature field, flow field, Lorentz force, and liquid fraction of large-size rare earth magnesium alloy with diameter of 750 mm under different electromagnetic parameters (magnetic field frequency and current intensity) in steady state of direct-chill (DC) casting were studied. The results reveal that using a magnetic field can reduce the temperature gradient and greatly accelerate the melt flow, the depth of the sump is reduced by about 50 mm. As the current intensity rises, the flow rate in the melt becomes accelerated, the sump depth becomes shallower, while the melt area with a liquid fraction of 0.5 to 0.63 increases. The Lorentz force rises as the magnetic field frequency increases, but the skin depth of the magnetic field decreases from 64.9 to 36.4 mm. [ABSTRACT FROM AUTHOR]

The advancement in science and technology has resulted in the invention and widespread usage of many electrical devices in the daily lives of humans. The exponential use of modern electronic facilities has increased electromagnetic field exposure in the current population. Therefore, the presented article deals with designing, constructing, and testing a new applicator system developed for cells electromagnetic biocompatibility studies. The applicator system is intended for studying the non-thermal impacts of low-frequency magnetic field on cell cultures growth. Main attention is focused on increasing the capacity of the applicator and effectivity of the experiments. The key idea is to reach high level of the magnetic field homogeneity in an area of interest and the temperature stability during the biocompatibility studies. The applicator system is designed based on numerical simulations and its construction, measurements, and properties evaluation are also reported for proving the applicator's functionality. The new applicator allows performing five parallel experiments at the same time under the same conditions. The simulation together with the experimental results confirm that the magnetic field homogeneity reaches 99% in the area of interest and the maximum temperature instability is lower than 2% during the experiments. The effectiveness of new applicator is tested and proved during preliminary experiments with Saccharomyces Cerevisiae cells. The observed effects of MF exposure represent maximal stimulation of 74% and maximal inhibition of 49%. The reason why MF with the same parameters induces inhibition in one sample and stimulation in the other will be the subject of further research. [ABSTRACT FROM AUTHOR]

To verify whether a low-frequency electromagnetic field (LFE field) can help reduce structural damage during the freeze–thaw process and maintain shelf life, Mongolian cheese was frozen at −10, −20, and −30 °C, then thawed at microwave or room temperature. Results showed that LFE field-assisted frozen treatment could reduce ice crystal size and protect the protein matrix structure of cheese. Frozen–thawed cheese retained 96.5% of its hardness and showed no significant difference from the fresh one in elasticity, cohesion, and chewiness. Frozen cheese showed similar but slower ripening behavior during storage, suggesting a potential application of the LFE field in the frozen storage of high-protein foods.

This article is focused on the in vitro experimental verification of the basic necessary conditions for valid interpretation of an ion parametric resonance prediction model of biological reaction on an externally applied, extremely low-frequency magnetic field. Experiments are performed on model organism Saccharomyces cerevisiae strain BY4741, with the intention to target calcium ions, which already produced interesting preliminary results within authors’ previous works, confirming specific magnetic field settings being bioactive. To study the nature and origin of biological reactions more exhaustingly, the research is aimed at two chosen physical aspects of ion parametric resonance theory. In the first part, experiments are set up to verify the resonance point validity for calcium ions and to perform a sensitivity analysis of the biological system response around this point. In the second part, the main attention is paid to the verification of the validity of maximum biological effect at specific BAC/BDC ratios, reflecting the ion parametric resonance theory as well as the current state of the art and knowledge. Both series of experiments have shown interesting results, confirming 29.89 Hz as a bioactive frequency for a BAC/BDC ratio of 1.8. These observations are in close correlation with the assumptions of the ion parametric resonance model for targeting calcium ions. The performed sensitivity analysis around the resonance point looks even more interesting, as conducted preliminary experiments resulted in two more pronounced bioactive frequencies of 24.89 and 34.89 Hz, in terms of biological response significance, than the resonance frequency assumed by an investigated prediction model. The narrow width of the peak, which is typical for physical phenomena of resonant nature, was not observed within this series of experiments, which would be addressed more precisely in future work of authors.

The advancement in science and technology has resulted in the invention and widespread usage of many electrical devices in the daily lives of humans. The exponential use of modern electronic facilities has increased electromagnetic field exposure in the current population. Therefore, the presented article deals with designing, constructing, and testing a new applicator system developed for cells electromagnetic biocompatibility studies. The applicator system is intended for studying the non-thermal impacts of low-frequency magnetic field on cell cultures growth. Main attention is focused on increasing the capacity of the applicator and effectivity of the experiments. The key idea is to reach high level of the magnetic field homogeneity in an area of interest and the temperature stability during the biocompatibility studies. The applicator system is designed based on numerical simulations and its construction, measurements, and properties evaluation are also reported for proving the applicator’s functionality. The new applicator allows performing five parallel experiments at the same time under the same conditions. The simulation together with the experimental results confirm that the magnetic field homogeneity reaches 99% in the area of interest and the maximum temperature instability is lower than 2% during the experiments. The effectiveness of new applicator is tested and proved during preliminary experiments with Saccharomyces Cerevisiae cells. The observed effects of MF exposure represent maximal stimulation of 74% and maximal inhibition of 49%. The reason why MF with the same parameters induces inhibition in one sample and stimulation in the other will be the subject of further research.

Low‐frequency electromagnetic field (LF‐EMF) stimulation is an emerging neuromodulation tool that is attracting more attention because of its non‐invasive and well‐controlled characteristics. However, the effect of different LF‐EMF features including the forms and the time of addition on neuronal activity has not been completely understood. In this study, we used multi‐electrode array (MEA) systems to develop a flexible in vitro magnetic stimulation device with plug‐and‐play features that allows for real‐time delivery of LF‐EMFs to biological tissues. Crucially, the method enables different forms of LF‐EMF to be added at any time to a long‐term potentiation (LTP) experiment without interrupting the process of LTP induction. We demonstrated that the slope of field excitatory postsynaptic potentials (fEPSPs) decreased significantly under post or priming uninterrupted sine LF‐EMFs. The fEPSPs slope would continue to decline significantly when LF‐EMFs were added two times with a 20‐min interval. Paired‐pulse ratio (PPR) was analyzed and the results reflected that LF‐EMFs induced LTP was expressed postsynaptically. The results of pharmacological experiments indicated that AMPA receptor activity was involved in the process of LTP loss caused by post‐LF‐EMFs. Moreover, the effect of priming sine or Quadripulse stimulation (QPS)‐patterned LF‐EMFs depended on the time interval between the end of LF‐EMF and the beginning of baseline recording. Interestingly, the effect of sine LF‐EMFs on LTP would not disappear within 120 min, while the impact of QPS‐patterned LF‐EMFs on LTP might disappear after 90 min. These results indicated that LF‐EMF might have a form‐ and time‐dependent effect on LTP. [ABSTRACT FROM AUTHOR]

The content of damaged 8-hydroxy-2-deoxyguanosine nitrogenous bases in the blood DNA of healthy donors and patients with epidermolysis bullosa after exposure to an alternating magnetic field of 550 ± 30 A/m in the frequency range from 3 to 60 Hz in vitro was determined using an enzyme immunoassay. The degree of oxidative DNA damage in epidermolysis bullosa was almost twice as high as in healthy donors. It was shown that there was a significant increase in the level of 8-oxoguanine in the DNA of both groups after the magnetic field treatment, which depended in a complex way on the frequency. The resulting effect is explained by the generation of reactive oxygen species under the influence of a magnetic field and the disruption of DNA repair processes. [ABSTRACT FROM AUTHOR]

Changes in Escherichia coli and Staphylococcus aureus reproduction were experimentally studied upon exposure of bacterial suspensions or the solvent (water) to a rectified electromagnetic field of a low frequency (4 Hz) and low intensity (~5.1–6 T) with various orientations of its vector with respect to the Z axis of the geomagnetic field. An increase in the total Z component of the field that influenced bacteria was associated with an accelerated formation of bacterial colonies, while a decrease in the component inhibited bacterial colony formation. [ABSTRACT FROM AUTHOR]

The effect of low-frequency electromagnetic field (LFEF) on temperature pattern and microstructure on both symmetry planes was investigated during the semi-continuous direct chilling (DC) casting process of magnesium slab. The distribution characteristics of magnetic flux density (B) and time average electromagnetic volume force density (F) were calculated. The weak value ofFwas found near the slab corner, which was clearly distinguished from the distribution ofB. According to the temperature measurement results, LFEF made the mushy region much flatter than that of conventional DC casting and it was much more obvious in the thickness direction. Compared with conventional DC casting, the low-frequency electromagnetic casting (LFEC) process could decrease the average temperature gradient between the centre and border in the mushy zone. The microstructures on both symmetry planes were also refined at different levels during the LFEC process. [ABSTRACT FROM PUBLISHER]

The effects of low-frequency electromagnetic field (LFEF) on nucleation during the pure aluminium solidification process are investigated. The experimental results show that the primary structure cannot be refined by applying LFEF on high-temperature liquid phase. The LFEF can dissociate the nuclei from the mould wall and disperse them uniformly when The LFEF is applied during the nucleation stage. However, the temperature at the middle of mould is higher than the liquidus temperature of pure aluminium, and the crystal nuclei cannot be preserved and grow up. [ABSTRACT FROM AUTHOR]

Electromagnetic field (EMF) treatment has proven to be effective against mineral scaling in water systems. Therefore, it should be assessed for the treatment of other deposits such as biofilms. In this study, a commercial device producing low-frequency EMF (1–10 kHz) was applied to a reactor fed with natural water for 45 days. The treatment promoted the concentration of microorganisms in suspension and limited the amount of sessile microorganisms in the biofilm, as determined by the measurement of total DNA, qPCR and microscopy. The structure of the bacterial community was assessed by t-RFLP and pyrosequencing analysis. The results showed that EMF treatment affected both planktonic and sessile community composition. EMFs were responsible for a shift in classes of Proteobacteria during development of the biofilm. It may be speculated that the EMF treatment affected particle solubility and/or microorganism hydration. This study indicated that EMFs modulated biofilm formation in natural water. [ABSTRACT FROM AUTHOR]

The super high strength aluminum alloy ingots with 100 mm in diameter were cast by the process of low-frequency electromagnetic horizontal continuous casting (LFEHC) and the effect of electromagnetic field on the as-cast microstructure was studied. Results show that microstructure of the sample prepared by the LFEHC process was greatly refined. Microstructures at the border and the center of the ingots were fine, uniform and rosette-haped.Electromagnetic frequency plays a key role in microstructure refining. Fine and uniform microstructures can be obtained with optimal electromagnetic frequency. In this experiment, under a frequency of 30 Hz the microstructure was the finest and the most uniform.

A chemiluminescence study showed that hepatitis B virus (HBV) and hepatitis C virus (HCV) DNA amplicons are capable of induced radiation when exposed to electromagnetic fields (EMFs) that range from 7.5 to 30 Hz in frequency and from 24 to 40 A/m in field strength. An EMF with a frequency of 9 Hz was shown to exert the greatest effect on aqueous solutions of the hepatitis virus DNA amplicons. The hydration shell of the DNA amplicons was observed to change. The change in the DNA hydration shell on exposure to a low-frequency EMF was presumed to restore hydrogen bonds, to induce crosslinks, and to facilitate DNA repair. [ABSTRACT FROM AUTHOR]

The effects of electromagnetic stirring and AlC grain refiner on the grain refinement of semi-continuously cast AZ31 magnesium alloy were discussed in this investigation. The results indicate that electromagnetic stirring has an effective refining effect on the grain size of AZ31 magnesium alloy under the effect of AlC grain refiner. Electromagnetic stirring can 'activate' the AlC particles, resulting in more heterogeneous nucleation sites for the primary α-Mg grains. But, longer holding time can 'deactivate' the AlC particles and poison the grain refining effect. [ABSTRACT FROM AUTHOR]

Stimulation of wheat seed germination by brief exposure in a 50-Hz electromagnetic field (EMF) is shown to depend on the extent of membrane stretching upon seed swelling in sucrose solutions. This again confirms the effect of low-frequency EMF on the release of peripheral proteins from membranes. Prolonged exposure, on the contrary, decreases the germination rate and retards seedling growth. [ABSTRACT FROM AUTHOR]

Abstract: A 50 Hz magnetic field effect on the growth of yeasts Saccharomyces cerevisae was studied. The cylindrical coil induced magnetic fields with inductions up to 10 mT. Duration of exposure varied up to 24 min. Exposure took place at laboratory temperature (24–26 °C) and the air ventilator maintained the temperature at the place of the sample. We measured the growth curves of yeasts in broth and we calculated the number of CFU (colony forming units) on solid soil. We found that magnetic field decreases the number of yeasts, and slowed down their growth. The result is similar to the experiments with bacteria E. coli, S. aureus and L. adecarboxylata. It seems that the magnetic fields kill a part of yeasts and the bigger part of them survives and continues in their growth. [Copyright &y& Elsevier]

Abstract: Enzymatic activity (denitrification) of Paracoccus denitrificans was estimated electrochemically by reduction of duroquinone (DQ). Graphite electrodes covered with whole bacterial cells behind a dialysis membrane were used for measurement. P. denitrificans reduce nitrate and/or nitrite under anaerobic conditions to nitrogen gas. DQ acts as an electron mediator. After donation of the electrons to the respiratory system of the bacteria, produced DQ is reduced to durohydroquinone on the electrode surface electrocatalytically. P. denitrificans were exposed to low-frequency magnetic field (10 mT, 50 Hz) for 24 min. In comparison with the control samples, the reduction peak of I–E curves that represent denitrification activity of the cells decreased significantly after magnetic field exposure. The decrease of the peak current was about 20%. The CFU-colony forming units-method was used to estimate the number of surviving bacteria. After 24 min exposure of 10 mT magnetic field P. denitrificans culture on electrode indicates 21% bacterial death. [Copyright &y& Elsevier]

The effect of a 50 Hz magnetic field on the growth of different bacterial strains was studied. We used bacteria with different cell shapes. We compared rod-shaped bacteria (E. coli, L. adecarboxylata) and spherical bacteria (S. aureus, P. denitrificans, S. paucimobilis, R. erythropolis). The growth curves of control and magnetic fields exposed samples were measured. The cylindrical coil induced magnetic fields with inductions up to 10 mT. Duration of exposure varied up to 24 min. Exposure took place at laboratory temperature (24–26°C) and the air ventilator maintained the temperature of sample. We observed the decrease of optical densities in exposed samples. The magnetic field effect was bigger for rod-like bacteria. We concluded that magnetic field effects depend on the shape of exposed cells. [ABSTRACT FROM AUTHOR]

Abstract: The horizontal direct chill (HDC) casting process is a well-established production route for aluminum alloy ingots but the ingot may some times suffer from inhomogeneous microstructures due to unbalanced cooling and the effect of gravity. In order to control the defect, a low-frequency electromagnetic field has been applied in HDC casting process and its influence has been studied. The results show that a low-frequency electromagnetic field can effectively reduce inhomogeneous microstructures in HDC castings. Two main parameters of the electromagnetic field—density and frequency, significantly influence the microstructures and solution distribution along the diameter of the ingot. The mechanisms of the effects of electromagnetic field have been discussed. [Copyright &y& Elsevier]

This work studies biological effects of low-frequency electromagnetic fields. We have exposed three different bacterial strains—Escherichia coli, Leclercia adecarboxylata and Staphylococcus aureus to the magnetic field (t<30 min, Bm=10 mT, f=50 Hz) in order to compare their viability (number of colony-forming units (CFU)). We have measured the dependence of CFU on time of exposure and on the value of the magnetic field induction Bm. Viability decreases with longer exposure time and/or higher induction Bm for all strains, but the quantity of the effect is strain-dependent. The highest decrease of the viability and the biggest magnetic field effect was observed with E. coli. The smallest magnetic field effect appears for S. aureus. From the measurement of the growth dynamics we have concluded that the decrease of the CFU starts immediately after the magnetic field was switched on. [Copyright &y& Elsevier]