Bioelectromagnetics最新文献

{"title":"The influence of eyelashes on electric field distribution and absorbed power density in the cornea under millimeter-wave exposure.","authors":"Negin Foroughimehr, Zoltan Vilagosh, Ali Yavari, Andrew Wood","doi":"10.1002/bem.22526","DOIUrl":"10.1002/bem.22526","url":null,"abstract":"<p><p>As millimeter wave (MMW) technology, particularly in fifth-generation (5G) devices, gains prominence, there is a crucial need for comprehensive electromagnetic (EM) models of ocular tissues to understand and characterize EM exposure conditions accurately. This study employs numerical modeling to investigate the interaction between MMW and the cornea, aiming to characterize EM field distributions and absorption within an anatomically accurate eye model while considering the influence of eyelashes. Using the finite-difference time-domain (FDTD) method, we conduct simulations of EM radiation interactions from 20.0 to 100.0 GHz with a human eye model. Moreover, we analyze the temperature distribution increase within the eye model using a thermal sensor in XFdtd, employing a scheme based on the finite difference (FD) method. Our findings reveal a nonuniform distribution of the EM field, particularly intensified in corneal regions adjacent to eyelashes and eyelids. Despite similar EM field patterns, the presence or absence of eyelashes has minimal impact on temperature differences. However, the study highlights increased radiation absorption by the eyelid's epidermis at 100.0 GHz, reducing the rise in the cornea's temperature.</p>","PeriodicalId":8956,"journal":{"name":"Bioelectromagnetics","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142457202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Protective effect of radiofrequency exposure against menadione-induced oxidative DNA damage in human neuroblastoma cells: The role of exposure duration and investigation on key molecular targets.","authors":"Anna Sannino, Mariateresa Allocca, Maria R Scarfì, Stefania Romeo, Olga Zeni","doi":"10.1002/bem.22524","DOIUrl":"10.1002/bem.22524","url":null,"abstract":"<p><p>In our previous studies, we demonstrated that 20 h pre-exposure of SH-SY5Y human neuroblastoma cells to 1950 MHz, UMTS signal, at specific absorption rate of 0.3 and 1.25 W/kg, was able to reduce the oxidative DNA damage induced by a subsequent treatment with menadione in the alkaline comet assay while not inducing genotoxicity per se. In this study, the same cell model was used to test the same experimental conditions by setting different radiofrequency exposure duration and timing along the 72 h culture period. The results obtained in at least three independent experiments indicate that shorter exposure durations than 20 h, that is, 10, 3, and 1 h per day for 3 days, were still capable to exert the protective effect while not inducing DNA damage per se. In addition, to provide some hints into the mechanisms underpinning the observed phenomenon, thioredoxin-1, heat shock transcription factor 1, heat shock protein 70, and poly [ADP-ribose] polymerase 1, as key molecular players involved in the cellular stress response, were tested following 3 h of radiofrequency exposure in western blot and qRT-PCR experiments. No effect resulted from molecular analysis under the experimental conditions adopted.</p>","PeriodicalId":8956,"journal":{"name":"Bioelectromagnetics","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142307078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical and analytical inspection of magnetic field effects in the radical pair mechanism by a simplified rate equation model.","authors":"Andreas Deser, Jens Kuhne, Heinrich A M Leymann","doi":"10.1002/bem.22528","DOIUrl":"10.1002/bem.22528","url":null,"abstract":"<p><p>The radical pair mechanism is by now the most prominent candidate for a biologically relevant quantum effect of magnetic fields. Recently, N. Ikeya and J. R. Woodward demonstrated a magnetic field effect for sub-extremely low frequency (ELF) fields in the mT range by investigating the autofluorescence spectrum of flavin adenine dinucleotide in living HeLa cells. We apply a simple rate equation model to show numerically and analytically that magnetic field effects can be expected to exist in the whole ELF range.</p>","PeriodicalId":8956,"journal":{"name":"Bioelectromagnetics","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142575226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterising core body temperature response of free-moving C57BL/6 mice to 1.95 GHz whole-body radiofrequency-electromagnetic fields.","authors":"Emma Sylvester, Chao Deng, Robert McIntosh, Steve Iskra, John Frankland, Raymond McKenzie, Rodney J Croft","doi":"10.1002/bem.22527","DOIUrl":"10.1002/bem.22527","url":null,"abstract":"<p><p>The present study investigated the core body temperature (CBT) response of free-moving adult male and female C57BL/6 mice, during and following a 2-h exposure to 1.95 GHz RF-EMF within custom-built reverberation chambers, using temperature capsules implanted within the intraperitoneal cavity and data continuously logged and transmitted via radiotelemetry postexposure. Comparing RF-EMF exposures (WBA-SAR of 1.25, 2.5, 3.75, and 5 W/kg) to the sham-exposed condition, we identified a peak in CBT within the first 16 min of RF-EMF exposure (+0.15, +0.31, +0.24, +0.37°C at 1.25, 2.5, 3.75, and 5 W/kg respectively; statistically significant at WBA-SAR ≥ 2.5 W/kg only), which largely dissipated for the remainder of the exposure period. Immediately before the end of exposure, only the CBT of the 5 W/kg condition was statistically differentiable from sham. Based on our findings, it is apparent that mice are able to effectively compensate for the increased thermal load at RF-EMF strengths up to 5 W/kg. In addition, the elevated CBT at the end of the exposure period in the 5 W/kg condition was statistically significantly reduced compared to the sham condition immediately after RF-EMF exposure ceased. This would indicate that measures of CBT following the end of an RF-EMF exposure period may not reflect the actual change in the CBT of mice caused by RF-EMF exposure in mice.</p>","PeriodicalId":8956,"journal":{"name":"Bioelectromagnetics","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142457201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Action potential threshold variability for different electrostimulation models and its potential impact on occupational exposure limit values.","authors":"Florian Soyka, Thomas Tarnaud, Carsten Alteköster, Ruben Schoeters, Tom Plovie, Wout Joseph, Emmeric Tanghe","doi":"10.1002/bem.22529","DOIUrl":"https://doi.org/10.1002/bem.22529","url":null,"abstract":"<p><p>Occupational exposure limit values (ELVs) for body internal electric fields can be derived from thresholds for action potential generation. These thresholds can be calculated with electrostimulation models. The spatially extended nonlinear node model (SENN) is often used to determine such thresholds. Important parameters of these models are the membrane channel dynamics describing the ionic transmembrane currents as well as the temperature at which the models operate. This work compares action potential thresholds for five different membrane channel dynamics used with the SENN model. Furthermore, two more detailed double-cable models by Gaines et al. (MRG-Sensory and MRG-Motor) are also considered in this work. Thresholds calculated with the SENN model and the MRG models are compared for frequencies between 1 Hz and 100 kHz and temperatures at 22°C and 37°C. Results show that MRG thresholds are lower than SENN thresholds. Deriving alternative ELVs from these thresholds shows that the alternative ELVs can change significantly with different ion channel dynamics (up to a factor of 22). Using the double cable model could lead to approximately ten times lower alternative exposure limit values. On the contrary, using the SENN model with different membrane channel dynamics could also lead to higher alternative exposure limit values. Therefore, future exposure guidelines should take the influence of different electrostimulation models into account when deriving ELVs.</p>","PeriodicalId":8956,"journal":{"name":"Bioelectromagnetics","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142567739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pulsed electromagnetic fields attenuate human musculocutaneous nerve damage induced by biceps eccentric contractions.","authors":"Karina Kouzaki, Koichi Nakazato","doi":"10.1002/bem.22525","DOIUrl":"10.1002/bem.22525","url":null,"abstract":"<p><p>Pulsed electromagnetic field (PEMF) therapy, a noninvasive treatment, has shown promise in mitigating nerve damage. However, unaccustomed exercises, such as eccentric contractions (ECCs), can damage both muscle and nerve tissue. This study investigated whether magnetic stimulation (MS) with PEMF could aid in nerve recovery after ECCs in the elbow flexors. Twenty participants were randomly assigned to either a control (CNT) or an MS group. Following ECCs, we measured the latency of the M-wave in the musculocutaneous nerve as an indicator of nerve function. Additionally, isometric torque, range of motion, and muscle pain were assessed for muscle function. Interestingly, only the CNT group exhibited a significant increase in latency on Day 2 (p < 0.05). The MS group, on the other hand, displayed an earlier recovery trend in isometric torque, range of motion, and muscle soreness. Notably, muscle soreness significantly decreased immediately after MS treatment compared to pretreatment levels. These findings suggest that MS treatment can effectively attenuate nerve damage induced by ECCs exercise.</p>","PeriodicalId":8956,"journal":{"name":"Bioelectromagnetics","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142307079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A comparative study of simulated electric fields of transcranial magnetic stimulation targeting different cortical motor regions","authors":"Jack Jiaqi Zhang, Bella Bingbing Zhang, Zhongfei Bai, Kenneth N. K. Fong","doi":"10.1002/bem.22523","DOIUrl":"https://doi.org/10.1002/bem.22523","url":null,"abstract":"This computational simulation study investigates the strength of transcranial magnetic stimulation (TMS)-induced electric fields (EF) in primary motor cortex (M1) and secondary motor areas. Our results reveal high interindividual variability in the strength of TMS-induced EF responses in secondary motor areas, relative to the stimulation threshold in M1. Notably, the activation of the supplementary motor area requires high-intensity stimulation, which could be attributed to the greater scalp-to-cortex distance observed over this area. These findings emphasize the importance of individualized planning using computational simulation for optimizing neuromodulation strategies targeting the cortical motor system.","PeriodicalId":8956,"journal":{"name":"Bioelectromagnetics","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142263617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nonlinearities and timescales in neural models of temporal interference stimulation.","authors":"Tom Plovie, Ruben Schoeters, Thomas Tarnaud, Wout Joseph, Emmeric Tanghe","doi":"10.1002/bem.22522","DOIUrl":"https://doi.org/10.1002/bem.22522","url":null,"abstract":"<p><p>In temporal interference (TI) stimulation, neuronal cells react to two interfering sinusoidal electric fields with a slightly different frequency ( <math> <semantics> <mrow> <mrow><msub><mi>f</mi> <mn>1</mn></msub> </mrow> </mrow> <annotation>${f}_{1}$</annotation></semantics> </math> , <math> <semantics> <mrow> <mrow><msub><mi>f</mi> <mn>2</mn></msub> </mrow> </mrow> <annotation>${f}_{2}$</annotation></semantics> </math> in the range of about 1-4 kHz, <math> <semantics> <mrow><mrow><mo>∣</mo> <msub><mi>f</mi> <mn>1</mn></msub> <mo>-</mo> <msub><mi>f</mi> <mn>2</mn></msub> <mo>∣</mo></mrow> </mrow> <annotation>$| {f}_{1}-{f}_{2}| $</annotation></semantics> </math> in the range of about 1-100 Hz). It has been previously observed that for the same input intensity, the neurons do not react to a purely sinusoidal signal at <math> <semantics> <mrow> <mrow><msub><mi>f</mi> <mn>1</mn></msub> </mrow> </mrow> <annotation>${f}_{1}$</annotation></semantics> </math> or <math> <semantics> <mrow> <mrow><msub><mi>f</mi> <mn>2</mn></msub> </mrow> </mrow> <annotation>${f}_{2}$</annotation></semantics> </math> . This study seeks a better understanding of the largely unknown mechanisms underlying TI neuromodulation. To this end, single-compartment models are used to simulate computationally the response of neurons to the sinusoidal and TI waveform. This study compares five different neuron models: Hodgkin-Huxley (HH), Frankenhaeuser-Huxley (FH), along with leaky, exponential, and adaptive-exponential integrate-and-fire (IF). It was found that IF models do not entirely reflect the experimental behavior while the HH and FH model did qualitatively replicate the observed neural responses. Changing the time constants and steady state values of the ion gates in the FH model alters the response to both the sinusoidal and TI signal, possibly reducing the firing threshold of the sinusoidal input below that of the TI input. The results show that in the modified (simplified) model, TI stimulation is not qualitatively impacted by nonlinearities in the current-voltage relation. In contrast, ion channels have a significant impact on the neuronal response. This paper offers insights into neuronal biophysics and computational models of TI stimulation.</p>","PeriodicalId":8956,"journal":{"name":"Bioelectromagnetics","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142054863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stimulus effects of extremely low-frequency electric field exposure on calcium oscillations in a human cortical spheroid.","authors":"Atsushi Saito, Takeo Shiina, Yoichi Sekiba","doi":"10.1002/bem.22521","DOIUrl":"https://doi.org/10.1002/bem.22521","url":null,"abstract":"<p><p>High-intensity, low-frequency (1 Hz to 100 kHz) electric and magnetic fields (EF and MF) cause electrical excitation of the nervous system via an induced EF (iEF) in living tissue. However, the biological properties and thresholds of stimulus effects on synchronized activity in a three-dimensional (3D) neuronal network remain uncertain. In this study, we evaluated changes in neuronal network activity during extremely low-frequency EF (ELF-EF) exposure by measuring intracellular calcium ([Ca²⁺]_i) oscillations, which reflect neuronal network activity. For ELF-EF exposure experiments, we used a human cortical spheroid (hCS), a 3D-cultured neuronal network generated from human induced pluripotent stem cell (hiPSC)-derived cortical neurons. A 50 Hz sinusoidal ELF-EF exposure modulated [Ca²⁺]_i oscillations with dependencies on exposure intensity and duration. Based on the experimental setup and results, the iEF distribution inside the hCS was estimated using high-resolution numerical dosimetry. The numerical estimation revealed threshold values ranging between 255-510 V/m (peak) and 131-261 V/m (average). This indicates that thresholds of neuronal excitation in the hCS were equivalent to those of a thin nerve fiber.</p>","PeriodicalId":8956,"journal":{"name":"Bioelectromagnetics","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142054864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A real-time working memory evaluation system for macaques in microwave fields","authors":"Bowen Li MSc,&nbsp;Xueyan Zhang PhD,&nbsp;Nan Qiao MSc,&nbsp;Jiawei Chen MSc,&nbsp;Weijie Bi,&nbsp;Weijia Zhi PhD,&nbsp;Lizhen Ma PhD,&nbsp;Congcong Miao,&nbsp;Lifeng Wang PhD,&nbsp;Yong Zou PhD,&nbsp;Xiangjun Hu PhD","doi":"10.1002/bem.22519","DOIUrl":"10.1002/bem.22519","url":null,"abstract":"<p>With the development and widespread application of electromagnetic technology, the health hazards of electromagnetic radiation have attracted much attention and concern. The effect of electromagnetic radiation on the nervous system, especially on learning, memory, and cognitive functions, is an important research topic in the field of electromagnetic biological effects. Most previous studies were conducted with rodents, which are relatively mature. As research has progressed, studies using non-human primates as experimental subjects have been carried out. Compared to rodents, non-human primates such as macaques not only have brain structures more similar to those of humans but also exhibit learning and memory processes that are similar. In this paper, we present a behavioral test system for the real-time evaluation of the working memory (WM) of macaques in a microwave environment. The system consists of two parts: hardware and software. The hardware consists of four modules: the operation terminal, the control terminal, the optical signal transmission, and detection module and the reward feedback module. The software program can implement the feeding learning task, the button-pressing learning task, and the delayed match-to-sample task. The device is useful for the real-time evaluation of the WM of macaques in microwave environments, showing good electromagnetic compatibility, a simple and reliable structure, and easy operation.</p>","PeriodicalId":8956,"journal":{"name":"Bioelectromagnetics","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141888453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}