Biophysics of magnetic orientation: strengthening the interface between theory and experimental design

The first demonstrations of magnetic effects on the behaviour of migratory birds and homing pigeons in laboratory and field experiments, respectively, provided evidence for the longstanding hypothesis that animals such as birds that migrate and home over long distances would benefit from possession of a magnetic sense. Subsequent identification of at least two plausible biophysical mechanisms for magnetoreception in animals, one based on biogenic magnetite and another on radical-pair biochemical reactions, led to major efforts over recent decades to test predictions of the two models, as well as efforts to understand the ultrastructure and function of the possible magnetoreceptor cells. Unfortunately, progress in understanding the magnetic sense has been challenged by: (i) the availability of a relatively small number of techniques for analysing behavioural responses to magnetic fields by animals; (ii) difficulty in achieving reproducible results using the techniques; and (iii) difficulty in development and implementation of new techniques that might bring greater experimental power. As a consequence, laboratory and field techniques used to study the magnetic sense today remain substantially unchanged, despite the huge developments in technology and instrumentation since the techniques were developed in the 1950s. New methods developed for behavioural study of the magnetic sense over the last 30 years include the use of laboratory conditioning techniques and tracking devices based on transmission of radio signals to and from satellites. Here we consider methodological developments in the study of the magnetic sense and present suggestions for increasing the reproducibility and ease of interpretation of experimental studies. We recommend that future experiments invest more effort in automating control of experiments and data capture, control of stimulation and full blinding of experiments in the rare cases where automation is impossible. We also propose new experiments to confirm whether or not animals can detect magnetic fields using the radical-pair effect together with an alternate hypothesis that may explain the dependence on light of responses by animals to magnetic field stimuli

Model of murine ventricular cardiac tissue for in vitro kinematic-dynamic studies of electromagnetic and beta2-adrenergic stimulation

In a model of murine ventricular cardiac tissue in vitro, we have studied the inotropic effects of electromagnetic stimulation (frequency, 75 Hz), isoproterenol administration (10 μM), and their combination. In particular, we have performed an image processing analysis to evaluate the kinematics and the dynamics of beating cardiac syncytia starting from the video registration of their contraction movement. We have found that the electromagnetic stimulation is able to counteract the β-adrenergic effect of isoproterenol and to elicit an antihypertrophic response

Low level microwave exposure decreases the number of male germ cells and affect vital organs of Sprague Dawley rats

The effects of 2.45 GHz microwave (MW) radiation on the vital tissues of Sprague Dawley rats were investigated. The various tissues assessed through histopathological assay were liver, kidney, heart, testis, ovary, fallopian tube, prostate, seminal vesicle and epididymis. The animals were exposed to various level of Specific Absorption Rate (SAR) which were 0 (control), 0.48, 0.95, 1.43, 1.91 and 2.39 W/kg using the microwave generator, model ER660E, Serial No MX704CCR from Toshiba UK Ltd for maximum period of ten minutes. From the results it was observed that the kidney and ovary were the most affected tissues in the female animals exposed to 2.45 GHz MW radiation when compared to the control. Hyperchromasia was observed in the ovary of the animals exposed to MW radiation. Vascular/glomerular congestion, interstitial spaces hemorrhage and tubular cells cloudiness was observed in the kidney. In the male animals, the testis and liver were the most affected organs when compared with control. There was reduction in the number of germ cells and cell disorganization observed from the testis of exposed group. The degree of reduction in the number of the germ cells varies with SARs, highest reduction was observed in the group V exposed to 2.39 W/kg which suggest that MW radiation has the potential to affects male fertility adversely. Oodema, cloudiness, glomeruli congestion was observed in the liver. There is no significant proof that the microwave radiation at this study frequency produces pathologic effects on the tissue studied except for the decrease in the number of germ cells and modification of some organs

THz in biology and medicine: toward quantifying and understanding the interaction of millimeter- and submillimeter-waves with cells and cell processes

As the application and commercial use of millimeter- and submillimeter-wavelength radiation become more widespread, there is a growing need to understand and quantify both the coupling mechanisms and the impact of this long wavelength energy on biological function. Independent of the health impact of high doses of radio frequency (RF) energy on full organisms, which has been extensively investigated, there exists the potential for more subtle effects, which can best be quantified in studies which examine real-time changes in cellular functions as RF energy is applied. In this paper we present the first real time examination of RF induced changes in cellular activity at absorbed power levels well below the existing safe exposure limits. Fluorescence microscopy imaging of immortalized epithelial and neuronal cells in vitro indicate increased cellular membrane permeability and nanoporation after short term exposure to modest levels (10-50 mW/cm2) of RF power at 60 GHz. Sensitive patch clamp measurements on pyramidal neurons in cortical slices of neonatal rats showed a dramatic increase in cellular membrane permeability resulting either in suppression or facilitation of neuronal activity during exposure to sub-μW/cm2 of RF power at 60 GHz. Non-invasive modulation of neuronal activity could prove useful in a variety of health applications from suppression of peripheral neuropathic pain to treatment of central neurological disorders

Genotoxic effects of low 2.45 GHz microwave radiation exposures on Sprague Dawley rats

This paper investigates the genotoxic effects of 2.45 GHz microwave (MW) radiation exposure at low specific absorption rates (SAR). 200 Sprague Dawley rats were exposed to SAR values between 0.48 and 4.30 W.kg-1 and the DNA of different tissues extracted, precipitated and quantified. Induced deoxyribonucleic acid (DNA) damages were assessed using the methods of DNA Direct Amplification of Length Polymorphisms (DALP) and the Single Cell Gel Electrophoresis (SCGE). Densitometric gel analysis demonstrated distinctly altered band patterns within the range of 40 and 120 bp in exposed samples and in the tail DNA of the same animals before exposure compared with control. Results were re-affirmed with SCGE (comet assay) for the same cells. Different tissues had different sensitivities to exposures with the brains having the highest. DNA damages were sex-independent. There was statistically significant difference in the Olive moment and % DNA in the tail of the exposed tissues compared with control (p < 0.05). Observed effects were attributed to magnetic field interactions and production of reactive oxygen species. We conclude that low SAR 2.45 GHz MW radiation exposures can induce DNA single strand breaks and the direct genome analysis of DNA of various tissues demonstrated potential for genotoxicity

Interaction of Radiofrequency Radiation with Biological Systems

Rapid advancement of radiofrequency (RF)-driven technologies has greatly affected our everyday lives. Increasing evidence led by in-vitro, in-vivo studies, epidemiological and clinical trials indicates that RF interacts considerably well with biological systems in various ways depending on different exposure parameters and properties of biological materials. Besides their innumerable benefits in different sectors of commercial and military fields, they can induce alterations in many physiological functions of the body, which may culminate into adverse human health consequences. The present article explicitly addresses the RF-based technologies and their applications, fundamentals of RF energy interaction with biological systems, exposure parameters, and dosimetry studies along with thermal and non-thermal effects on different vital organs at molecular and cellular levels. Further, this article outlines the limitations of RF-induced biological effect studies, status of risk assessment, safety levels and its future perspectives

Cell bystander effect induced by radiofrequency electromagnetic fields and magnetic nanoparticles

Induced effects by direct exposure to ionizing radiation (IR) are a central issue in many fields like radiation protection, clinic diagnosis and oncological therapies. Direct irradiation at certain doses induce cell death, but similar effects can also occur in cells no directly exposed to IR, a mechanism known as bystander effect. Non-IR (radiofrequency waves) can induce the death of cells loaded with MNPs in a focused oncological therapy known as magnetic hyperthermia. Indirect mechanisms are also able to induce the death of unloaded MNPs cells. Using in vitro cell models, we found that colocalization of the MNPs at the lysosomes and the non-increase of the temperature induces bystander effect under non-IR. Our results provide a landscape in which bystander effects are a more general mechanism, up to now only observed and clinically used in the field of radiotherapy.Comment: 16 pages, 4 figures, submitted to International Journal of Radiation Biolog

Roadmap on semiconductor-cell biointerfaces.

This roadmap outlines the role semiconductor-based materials play in understanding the complex biophysical dynamics at multiple length scales, as well as the design and implementation of next-generation electronic, optoelectronic, and mechanical devices for biointerfaces. The roadmap emphasizes the advantages of semiconductor building blocks in interfacing, monitoring, and manipulating the activity of biological components, and discusses the possibility of using active semiconductor-cell interfaces for discovering new signaling processes in the biological world

Positive correlation between ELF and RFelectromagnetic fieldon cancer risk

Extremely low frequency (ELF) and Radio frequency (RF) electromagnetic field may affect biological systems by raising generation free radicals by decline activities of glutathione peroxidase dismutase or increase in the lifetime of free radicals with inhibited pretreatment of cells antioxidant like that alpha tocopherol. ELF and  RF electromagnetic  field maycan damaged DNA  with raising level  hydroxyl radicals in cells and  it is  can interact DNA and form mainly 8-hydroxy-2′–deoxyguanosine( 8-OHdG) adducts. Many study showed   Electromagnetic field radiation(EMF) can change gene expression and conformation of protein. It may declineexpression of some genes such as superoxide dismutase orraise expressionof certain genes such as Hsps (heat shock proteins). ELF and RFelectromagnetic field   can effects on homeostasis Ca2+ and alteration in important cellular and molecular processes such as differentiation, proliferation, gene expression, cytoskeletal reorganization and metabolism. Use of radio frequency electromagneticfield onsatellite jamming in Iran and some country may can harmful to human health and it could be a risk factor for cancer