Effect Of Weak Magnetic Field Research Articles

Effects of high voltage electrostatic field and weak magnetic field assisted refrigeration on preservation of spinach

Effects of high voltage electrostatic field and weak magnetic field assisted refrigeration on preservation of spinach

Molecular Biological Effects of Weak Low-Frequency Magnetic Fields: Frequency-Amplitude Efficiency Windows and Possible Mechanisms.

This review covers the phenomenon of resonance-like responses of biological systems to low-frequency magnetic fields (LFMF). The historical development of this branch of magnetobiology, including the most notable biophysical models that explain the resonance-like responses of biological systems to LFMF with a specific frequency and amplitude, is given. Two groups can be distinguished among these models: one considers ion-cofactors of proteins as the primary targets for the LFMF influence, and the other regards the magnetic moments of particles in biomolecules. Attention is paid to the dependence of resonance-like LFMF effects on the cell type. A radical-pair mechanism of the magnetic field's influence on biochemical processes is described with the example of cryptochrome. Conditions for this mechanism's applicability to explain the biological effects of LFMF are given. A model of the influence of LFMF on radical pairs in biochemical oscillators, which can explain the frequency-amplitude efficiency windows of LFMF, is proposed.

On the anisotropic weak magnetic field effect in radical-pair reactions.

For more than 60 years, scientists have been fascinated by the fact that magnetic fields even weaker than internal hyperfine fields can markedly affect spin-selective radical-pair reactions. This weak magnetic field effect has been found to arise from the removal of degeneracies in the zero-field spin Hamiltonian. Here, I investigated the anisotropic effect of a weak magnetic field on a model radical pair with an axially symmetric hyperfine interaction. I found that S-T± and T0-T± interconversions driven by the smaller x and y-components of the hyperfine interaction can be hindered or enhanced by a weak external magnetic field, depending on its direction. Additional isotropically hyperfine-coupled nuclear spins preserve this conclusion, although the S → T± and T0 → T± transitions become asymmetric. These results are supported by simulating reaction yields of a more biologically plausible, flavin-based radical pair.

Effect of weak magnetic field on the water-holding properties, texture, and volatile compounds of pork and beef during frozen storage

The weak magnetic field has recently attracted much attention for improving the quality of frozen food due to its mild effectiveness and near-complete transmission through the food matrix. This study aimed to explore the effect of the magnetic field with 1 mT and 50 Hz on the freezing process and storage quality of pork and beef. The results showed that the freezing point of beef stored under the magnetic field was −1.7 °C, which was 0.5 °C lower than that of conventional frozen (CF) groups, and the phase transition times of pork and beef were reduced by 55.56% and 50.00%, respectively. The magnetic field maintained higher water-holding capacity and decreased drip loss and cooking loss for both types of meat. Coherently, the evaporation and redistribution of water was inhibited by MF, as indicated by the magnetic resonance imaging results. The magnetic field also effectively moderated the hardening in texture, odor deterioration and color change of frozen pork and beef. Less accumulation of free amino acids suggested the degradation of protein was suppressed under magnetic field . The present study would provide a scientific reference for the application of weak magnetic field in meat preservation.

Effect of external magnetic field on mass transport of reactive species in the reaction between nano zero valent iron and selenate anions in a simulated flue gas desulfurization wastewater

The mechanism involved in the reaction of regulated ions with nano Zero-Valent Iron (ZVI) in the presence of an applied weak magnetic field (WMF) was investigated. The WMF effect on mass transport of reacting ions and morphology and composition of the oxide layer in nano ZVI was elucidated using Electron Energy Loss Spectroscopy (EELS). The magnetic gradient force produced by ferromagnetic ZVI particles had a greater influence on the rate of selenate diffusion in solution than the Lorentz force due to the externally applied weak magnetic field. Moreover, the magnetic gradient force was suggested to suppress ZVI corrosion reactions. Despite changes in the iron oxide layer under the WMF influence, the rate of selenate reduction has not been significantly affected over short term lasting several hours. Most crucially, WMF had a negligible effect on the rate of mass transport of selenate anions, as compared to the dominant effect of forced convection.

First-order transitions in spin chains coupled to quantum baths

We show that tailoring the dissipative environment allows us to change the features of continuous quantum phase transitions and even induce first-order transitions in ferromagnetic spin chains. In particular, using a numerically exact quantum Monte Carlo method for the paradigmatic Ising chain of one-half spins in a transverse magnetic field, we find that spin couplings to local quantum boson baths (in the Ohmic regime) can drive the transition from the second to the first order even for a low dissipation strength. Moreover, using a variational mean-field approach for the treatment of spin-spin and spin-boson interactions, we point out that phase discontinuities are ascribable to a dissipation-induced effective magnetic field which is intrinsically related to the bath quantum fluctuations and vanishes for classical baths. The effective field is able to switch the sign of the magnetization along the direction of spin-spin interactions. The results can be potentially tested in recent quantum simulators and are relevant for quantum sensing since the spin system could not only detect the properties of nonclassical baths, but also the effects of weak magnetic fields.

Statistical Amplification of the Effects of Weak Magnetic Fields in Cellular Translation.

We assume that the enzymatic processes of recognition of amino acids and their addition to the synthesized molecule in cellular translation include the formation of intermediate pairs of radicals with spin-correlated electrons. The mathematical model presented describes the changes in the probability of incorrectly synthesized molecules in response to a change in the external weak magnetic field. A relatively high chance of errors has been shown to arise from the statistical enhancement of the low probability of local incorporation errors. This statistical mechanism does not require a long thermal relaxation time of electron spins of about 1 μs-a conjecture often used to match theoretical models of magnetoreception with experiments. The statistical mechanism allows for experimental verification by testing the usual Radical Pair Mechanism properties. In addition, this mechanism localizes the site where magnetic effects originate, the ribosome, which makes it possible to verify it by biochemical methods. This mechanism predicts a random nature of the nonspecific effects caused by weak and hypomagnetic fields and agrees with the diversity of biological responses to a weak magnetic field.

Effects of Weak Magnetic Fields on Plant Chemical Composition and Its Ecological Implications

The exposure of plants to weak magnetic fields (MFs) of various intensities and for different times is increasingly adopted to sustainably enhance plant growth in plant-based applications such as modern agriculture, phytoremediation and biogas production. However, little is known about the effects of MF exposure on plant chemical composition, and in turn on related ecosystem processes, such as the transfer of potentially toxic elements along food chains and the decomposition of organic matter. To fill this gap, the present research, through the study of the chemical composition of four edible crops (leaves of lettuce, parsley and basil, and fruits of tomato) differently exposed to weak MFs (75 Hz; 1.5 mT), aimed at evaluating the overall effects of the exposure on ecosystem processes. In particular, several essential (B, C, Ca, Cu, K, Fe, Mg, Mn, Mo, N, Ni, P, S, Zn), beneficial (Co, Na, Se, Si) and non-useful (Al, As, Ba, Cd, Cr, Li, Pb, Sr, Ti, V) elements, together with chemical compounds and derived parameters (soluble sugars, starch, chlorophylls, flavonoids, anthocyanins, nitrogen balance index), indicators of plant metabolism and health, and litter decomposability traits (C/N, C/P), were analyzed. Notwithstanding the expected variations in the observed effects among species and MF exposure conditions, the obtained results highlight a general decrease in most of the studied parameters (with the exception of those related to litter decomposability), attributable to a lower absorption/accumulation of the studied chemical elements and to a reduced synthesis of metabolites. The largest average reduction was observed for the non-useful elements, which outweighs the reduction in essential and beneficial elements and provides for an important MFinduced effect, considering their toxic, persistent and biomagnificable characteristics. Similarly, the induced increases in C/N and C/P ratios indicate the production of litter more recalcitrant to the decomposition process, suggesting that weak MF treatments may be useful to enhance soil C storage and reduce CO2 emissions.

Effects of weak magnetic field and finite chemical potential on the transport of charge and heat in hot QCD matter

We have studied the effects of weak magnetic field and finite chemical potential on the transport of charge and heat in hot QCD matter by estimating their respective response functions, viz. the electrical conductivity ( $$\sigma _{\textrm{el}}$$ ), the Hall conductivity ( $$\sigma _{\textrm{H}}$$ ), the thermal conductivity ( $$\kappa _0$$ ) and the Hall-type thermal conductivity ( $$\kappa _1$$ ). The expressions of charge and heat transport coefficients are obtained by solving the relativistic Boltzmann transport equation in the relaxation time approximation at weak magnetic field and finite chemical potential. The interactions among partons are incorporated through their thermal masses. We have observed that $$\sigma _{{\textrm{el}}}$$ and $$\kappa _0$$ decrease and $$\sigma _{{\textrm{H}}}$$ and $$\kappa _1$$ increase with the magnetic field in the weak magnetic field regime. On the other hand, the presence of a finite chemical potential increases these transport coefficients. The effects of weak magnetic field and finite chemical potential on aforesaid transport coefficients are found to be more conspicuous at low temperatures, whereas at high temperatures, they have only a mild dependence on magnetic field and chemical potential. We have found that the presence of finite chemical potential further extends the lifetime of the magnetic field. Furthermore, we have explored the effects of weak magnetic field and finite chemical potential on the Knudsen number, the elliptic flow coefficient and the Wiedemann–Franz law.

Crystalline-magnetism action in biomimetic mineralization of calcium carbonate

The influence of minor environmental factors, such as the geomagnetic field, on the biomineralization of nacres, is often ignored but a great deal of research has confirmed its important role in the normal mineralization of calcium carbonate. Although the geomagnetic field is weak, its cumulative effects need to be considered given that the biomineralization process can take years. Accordingly, the authors of this paper have investigated the effects of weak magnetic fields (25 Gs or 50 Gs) on calcium carbonate mineralization and analyzed the mechanism involved. The results show that even a weak magnetic field conduces to the formation of vaterite or aragonite, in the induction order of precursor → vaterite → aragonite. The stronger the magnetic field and the longer the time, the more obvious the induction effect. The effect of a magnetic field is strongest in the aging stage and weakest in the solution stage. Inductions by egg-white protein and by a magnetic field inhibit each other, but they both restrict particle growth. These findings highlight the importance of minor environmental factors for biomineralization and can serve as a reference for biomimetic preparation of a CaCO3 nacre-like structure and for anti-scale technology for circulating cooling water.

On the quantum nature of magnetic phenomena in biology

The review discusses the microscopic mechanisms of the action of weak magnetic fields on organisms. Magnetobiology distinguishes between magnetoreception, i.e., the effect of a magnetic field on specialized receptors, and a nonspecific response that develops without such receptors. The nonspecific effects of weak magnetic fields are highly general and universal: they occur in all organisms. Often these effects are disguised as the result of the action of uncontrolled random factors, appear as an increased scatter of measurements, and accompanied by low reproducibility. The nature of nonspecific magnetic effects, as is shown in this review, is related to the quantum dynamics of the magnetic moments of electrons, magnetic nuclei, and, possibly, rotations of molecular groups. Among the most substantiated is the spin-chemical mechanism, first of all. Its known low sensitivity to weak magnetic fields can be increased by including spin-correlated radical pairs in the enzymes that catalyze biopolymer processes, e.g., ribosomal ones. We show that research on the effects of significantly weakened magnetic fields compared with the geomagnetic field on cellular processes has prospects for various practical applications. The mechanisms proposed to explain nonspecific effects, but turned out to be untenable, are listed.

Effect of weak alternating magnetic fields on neutrophilic granulocytes. An analytical review

The article discusses the main achievements in recent years in studying the biological effects of weak and superweak low-frequency magnetic fields, either variable or combined with constant ones. Considered are neutrophil granulocytes activated by chemical stimulants or intact when the magnetic fields affect isolated cells, blood, and whole organisms. The methods include recording changes in ROS concentration levels (the most noticeable effect of exposure to a weak magnetic field), priming index, calcium homeostasis, proliferative activity, immune status, as well as the influence of various chemical agents on these indicators. The leading methods in this field are fluorescence spectrometry and chemiluminescence analysis. The experimental results indicate the biological effectiveness of this physical factor, the specific effect of which depends on the type of biosystem, its functional status, the environment, and the parameters of the fields themselves. The data obtained can have applied significance in magnetotherapy, immune response optimization in various diseases, acceleration of tissue regeneration and repair, and increasing the body's resistance to infections. They also can have academic significance since they help to identify the primary field acceptors and magnetic targets and their localization in the cell, study relationships with signal cascades, build models of biological signal amplification pathways, and find biologically significant frequencies and field amplitudes.

Investigation for effect of weak electric and magnetic fields at black spots on concrete pavement

Roads are valuable assets worldwide that must be kept in good condition with minimum maintenance to safeguard against accident. From the literature review and the field observations, it is quite evident that geo-fields are one of the parameters which is responsible for damaging the road surface and hence further increasing the possibility of accidents. Present study is an attempt to provide a detailed insight into the performance of the road segment when subjected to geo-fields. For the same accident data of the Mumbai-Pune expressway, over six years from 2016 to 2021 has been used. Based on this data 46 accident black spots were segregated for investigation. An automated method is used to measure the pavement roughness index (PRI). On these spots, the quality of pavement is determined using the non– destructive test of Ultra Sonic Pulse Velocity (UPV). Geo-fields are measured in terms of electric and magnetic fields at these black spots. Data has been analyzed using Karl Pearson’s correlation coefficient and linear regression models are developed for the average number of road accidents (Ā) with respect to PRI, UPV and Geo-fields. The mathematical models developed may provide a useful link between road accidents, geo-fields, and pavement surface conditions. It will also help transport authorities not only to predict the number of accidents at particular spots envisaged on existing expressway but will also enable them to design pavements appropriately for the detrimental effects of weak electric and magnetic fields.

Aerobic granulation and microbial community succession in sequencing batch reactors treating the low strength wastewater: The dual effects of weak magnetic field and exogenous signal molecule

The application of magneto-biological effects in wastewater treatment has been brought under the spotlight recently. This work explored the dual effects of magnetic field (MF) and exogenous N-hexanoyl-l-homoserine lactone (C6-HSL) on activated sludge granulation. Results showed that exposure to MF and C6-HSL obviously accelerated the aerobic granulation process and promoted the secretion of extracellular polymeric substances, especially polysaccharides, humic acid-like substances, aromatic proteins, and tryptophan-like substrates. Illumina MiSeq sequencing results indicated that the introduction of MF and C6-HSL can increase the diversity and richness of microbial community without antagonism, and the biological basis for rapid granulation process in this study was the enrichment of slow-growing bacteria Candidatus_Competibacter. Besides, the overgrowth of filamentous bacteria Thiothrix could be suppressed due to the presence of MF, improving the stabilities of aerobic granular sludge. This study provides a new understanding of the MF and C6-HSL effects on rapid aerobic granulation when treating the low-strength wastewater.

Effects of weak static magnetic fields on the development of seedlings of Arabidopsis thaliana.

To study magnetoreception of Arabidopsis thaliana, we analysed several developmental responses including cryptochrome-independent seed germination and the phytochrome- and cryptochrome-dependent hypocotyl elongation and photo-accumulation of anthocyanins and chlorophylls in weak static magnetic fields ranging from near null to 122 μT. A field of 50 μT accelerated seed germination by about 20h relative to samples maintained in a near-null field. The double mutant, cry1cry2, lacking cryptochromes 1 and 2 displayed the same magnetic field-induced germination acceleration under blue light as the wild-type strain. Magnetic field-induced germination acceleration was masked in the presence of exogenous sucrose. Stimulus-response curves for hypocotyl elongation in a range between near-null to 122 μT indicated maxima near 9 and 60 μT for the wild-type strain as well as mutant cry1cry2. The photo-accumulation of anthocyanins and chlorophylls could be effectively modulated by magnetic fields in the presence of low-irradiance red and blue light, respectively. The findings indicate that Arabidopsis thaliana possesses light-independent mechanisms of magnetic field reception, which remain presently unidentified. Our results are in better agreement with predictions of the level crossing mechanism (LCM) of magnetoreception rather than those of the cryptochrome-associated radical-pair mechanism (RPM).

In vivo low-intensity magnetic pulses durably alter neocortical neuron excitability and spontaneous activity.

Magnetic brain stimulation is a promising treatment for neurological and psychiatric disorders. However, a better understanding of its effects at the individual neuron level is essential to improve its clinical application. We combined focal low-intensity repetitive transcranial magnetic stimulation (LI-rTMS) to the rat somatosensory cortex with intracellular recordings of subjacent pyramidal neurons in vivo. Continuous 10Hz LI-rTMS reliably evoked firing at ∼4-5Hz during the stimulation period and induced durable attenuation of synaptic activity and spontaneous firing in cortical neurons, through membrane hyperpolarization and a reduced intrinsic excitability. However, inducing firing in individual neurons by repeated intracellular current injection did not reproduce the effects of LI-rTMS on neuronal properties. These data provide a novel understanding of mechanisms underlying magnetic brain stimulation showing that, in addition to inducing biochemical plasticity, even weak magnetic fields can activate neurons and enduringly modulate their excitability. KEY POINTS: Repetitive transcranial magnetic stimulation (rTMS) is a promising technique to alleviate neurological and psychiatric disorders caused by alterations in cortical activity. Our knowledge of the cellular mechanisms underlying rTMS-based therapies remains limited. We combined in vivo focal application of low-intensity rTMS (LI-rTMS) to the rat somatosensory cortex with intracellular recordings of subjacent pyramidal neurons to characterize the effects of weak magnetic fields at single cell level. Ten minutes of LI-rTMS delivered at 10Hz reliably evoked action potentials in cortical neurons during the stimulation period, and induced durable attenuation of their intrinsic excitability, synaptic activity and spontaneous firing. These results help us better understand the mechanisms of weak magnetic stimulation and should allow optimizing the effectiveness of stimulation protocols for clinical use.

Investigation of the effect of sustainable magnetic treatment on the microbiological communities in drinking water

The drinking water scarcity is posing a threat to mankind, hence better water quality management methods are required. Magnetic water treatment, which has been reported to improve aesthetic water quality and reduce scaling problems, can be an important addition to the traditional disinfectant dependent treatment. Despite the extensive market application opportunities, the effect of magnetic fields on (microbial) drinking water communities and subsequently the biostability is still largely unexplored, although the first patent was registered already 1945.Here flow cytometry was applied to assess the effect of weak magnetic fields (≤10 G) with strong gradients (≈800 G/m) on drinking water microbial communities. Drinking water was collected from the tap and placed inside the magnetic field (treated) and 5 m away from the magnet to avoid any background interferences (control) using both a static set-up and a shaking set-up. Samples were collected during a seven-day period for flow cytometry examination. Additionally, the effects of magnetic fields on the growth of Pseudomonas aeruginosa in autoclaved tap water were examined. Based on the fluorescent intensity of the stained nucleic acid content, the microbial cells were grouped into low nucleic acid content (LNA) and high nucleic acid content (HNA). Our results show that the LNA was dominant under nutrient limited condition while the HNA dominates when nutrient is more available. Such behavior of LNA and HNA matches well with the long discussed r/K selection model where r-strategists adapted to eutrophic conditions and K-strategists adapted to oligotrophic conditions. The applied magnetic fields selectively promote the growth of LNA under nutrient rich environment, which indicates a beneficial effect on biostability enhancement. Inhibition on an HNA representative Pseudomonas aeruginosa has also been observed. Based on our laboratory observations, we conclude that magnetic field treatment can be a sustainable method for microbial community management with great potential.

P 68 Unintentional maladjustment of a shunt valve due to electromagnetic door locks – A case report

Normal-pressure hydrocephalus is caused by dilatation of the internal cerebrospinal fluid spaces at normal intracranial pressure. The resulting progressive accumulation of CSF in the brain space can cause permanent damage and, if left untreated, complete loss of brain tissue [2, 4]. The standard treatment for hydrocephalus in children and adults is the implantation of a ventriculo-peritoneal shunt (VP shunt). Most of the currently used shunt systems have a valve to control pressure and drain CSF if necessary [4]. In recent years, malfunction of programmable VP shunts has been reported in patients exposed to strong electromagnetic fields, such as those generated during magnetic resonance imaging (MRI) [1, 3]. However, little is known about the effects of weak magnetic fields on VP shunts. We present the case of a 53 -year-old forensic psychiatric patient in whom the pressure setting of an implanted Codman-Hakim programmable shunt valve changed during passage through various ward doors, leading to the onset of psychiatric symptoms. During the inpatient stay, the valve's pressure setting changed at least six times randomly despite frequent reprogramming and monitoring. References 1 Akbar M, Aschoff A, Georgi JC, Nennig E, Heiland S, Abel R, Stippich C (2010) Adjustable Cerebrospinal Fluid Shunt Valves in 3.0-Tesla MRI: a Phantom Study using Explanted Devices. Rofo 182(7):594-602 2 Kahle KT, Kulkarni AV, Limbrick DD, Warf BC (2016) Hydrocephalus in children. Lancet 387(10020):788–799 3 Mirzayan MJ, Klinge PM, Samii M, Goetz F, Krauss JK (2012) MRI safety of a programmable shunt assistant at 3 and 7 Tesla. Br J Neurosurg 26(3):397-400 4 Portillo Medina SA, Franco JVA, Ciapponi A, Garotte V, Vietto V (2017) Ventriculo-peritoneal shunting devices for hydrocephalus. Cochrane Database Syst Rev. 2017(7): CD012726 Figure 1. Scetch of a Codman-Hakim shunt valve. Figure 2. Image of a Codman-Hakim VP shunt before and after passing a door.

A Brief Review of the Current State of Research on the Biological Effects of Weak Magnetic Fields

A Brief Review of the Current State of Research on the Biological Effects of Weak Magnetic Fields

Weak magnetic field-dependent photoluminescence properties of lead bromide perovskites

The strong spin–orbit coupling (SOC) in lead halide perovskites, when inversion symmetry is lifted, has provided opportunities for investigating the Rashba effect in these systems. Moreover, the strong orbital moment, which, in turn, impacts the spin-pair in singlet and triplet electronic states, plays a significant role in enhancing the optoelectronic properties in the presence of external magnetic fields in lead halide perovskites. Here, we investigate the effect of weak magnetic fields (<1 T) on the photoluminescence (PL) properties of CsPbBr3 nanocrystals with and without Ruddlesden–Popper (RP) faults and single crystals of CH3NH3PbBr3. Along with an enhancement in the PL intensity as a function of an external magnetic field, which is observed in both lead bromide perovskites, the PL emission red-shifts in CsPbBr3 nanocrystals. Density-functional theory calculations of the electronic band-edge in CsPbBr3 show almost no change in the energy gap as a function of the external magnetic field. The experimental results, thus, suggest the role of mixing of the triplet and singlet excitonic states under weak magnetic fields. This is further deduced from an enhancement in PL lifetimes as a function of the field in CsPbBr3. In CH3NH3PbBr3, an increase in PL intensity is observed under weak magnetic fields; however, no changes in the peak energy or PL lifetimes are observed. The internal magnetic fields due to SOC are characterized for all three samples and found to be the highest for CsPbBr3 nanocrystals with RP faults.