Search Results (112)

The growing use of wireless technology significantly increases the exposure of all living organisms to radiofrequency electromagnetic fields (RF-EMF). However, the physiological effects of RF-EMF on plants have not yet been sufficiently researched. In this study, we investigated the effects of RF-EMF radiation in the frequency ranges 1890–1900 MHz (DECT) and 2.4 GHz plus 5 GHz (Wi-Fi) on photosynthetic performance of Tilia plants (Tilia tomentosa). The recorded fast chlorophyll fluorescence transients were used to analyze the structure and function of PSII by the JIP-test. The analysis of the fluorescence of chlorophyll a showed that the RF-EMF interfered with the electron transport processes of photosynthesis. Tilia plants exposed to RF-EMF induced decrease in photosynthetic efficiency (F_V/F_M) and inactivation of part of PSII reaction centers (RC/CS_O). Observations of leaf senescence and lifespan over a period of 102 days showed that RF-EMF-exposed Tilia plants exhibited accelerated aging. Full article

Exposure to electromagnetic fields (EMFs) at different frequencies has been reported to induce apoptotic changes in brain tissue. Apoptosis is commonly evaluated using the TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling) method; however, conventional semi-quantitative scoring is subjective and may vary between observers. Therefore, this study aimed to evaluate the feasibility of transfer learning-based convolutional neural network (CNN) models for the objective and automated classification of apoptotic damage in TUNEL-stained brain sections. A total of 92 light microscopy images of TUNEL-stained rat brain tissue, obtained from experimental groups, were analyzed. Apoptotic damage was categorized into three classes (0: no, +1: slight, +2: moderate) based on semi-quantitative scoring. Pre-trained convolutional neural network models, including AlexNet, SqueezeNet, GoogLeNet, Inception-v3, and ResNet-101, were applied for image classification. All models were able to classify apoptotic damage levels, defined by the extent of TUNEL staining, from images with varying performance. The best-performing model achieved high classification accuracy and demonstrated strong agreement with manual scoring, as determined by visual assessments by experts. The models successfully distinguished between different levels of apoptotic damage observed across experimental groups. The findings suggest that transfer learning-based CNN models may provide an objective and reproducible approach for the classification of apoptotic damage in TUNEL-stained histopathological images, thereby reducing observer-dependent variability. This approach may also support histopathological evaluation in experimental models, including studies investigating EMF-induced brain injury. Full article

Background/Objectives: Amplitude-modulated radiofrequency (AMRF) fields have emerged as promising non-temperature-induced strategies in oncology. While conventional hyperthermia (HT) relies on thermal stress, the biological impact of AMRF, particularly in combination with radiotherapy (RT), remains insufficiently characterized. Methods: We assessed RF and AMRF, alone or with RT, using phenotypic analyses of proliferation, apoptosis, and necrosis across four cancer cell lines (HT29, SW620, U343, U138). Transcriptomic profiling with Kyoto Encyclopedia of Genes and Genomes (KEGG), GO:BP, and Reactome enrichment was performed in SW620 and U138 cells, selected for their strong phenotypic responses. Results: Across the panel, AMRF was associated with broader cytotoxic responses than RF or HT in most but not all cell lines. AMRF+RT produced the strongest necrotic responses, with cell-line-specific exceptions identified explicitly in the Results (the absence of a significant AMRF+RT apoptotic effect in SW620 and the absence of a significant AMRF+RT necrotic response in U343). In SW620 cells, AMRF was associated with extensive transcriptional reprogramming involving immune modulation, extracellular matrix remodeling, and cell cycle regulation, whereas RF alone showed narrower and delayed effects. In contrast, U138 cells showed elevated apoptosis and necrosis but limited transcriptional changes—a phenotype–transcriptome divergence that points to mechanisms operating downstream of transcription and warrants functional investigation in dedicated follow-up studies. Conclusions: AMRF and AMRF+RT emerge as promising non-temperature-induced anticancer modalities in the cell-line models profiled here, with the pattern of response varying between cell lines. These findings expand the biological impact of RF-based treatments and set the grounds for further investigation in mechanistic and translational studies. Full article

A compact millimeter-wave radar system operating at 33 GHz is presented for integration on small unmanned aerial systems (UAS) and for ground-based counter-UAS reconnaissance. The design is specifically motivated by civil-sector agricultural applications, where large-payload crop-dusting and precision-spraying drones operating under FAA 14 CFR Part 137 require lightweight sense-and-avoid radar that conforms aerodynamically to existing aircraft or ground vehicles. The system is based on a 36-element hemispherical conformal phased array of crossed half-wave dipole radiators that generate right-hand circular polarization (RHCP) on transmit and selectively receives left-hand circular polarization (LHCP) echoes from targets, providing passive first-stage suppression of co-polarized rain and ground clutter. A Linearly Constrained Minimum Variance (LCMV) digital beamformer, applied to per-element analog-to-digital converter (ADC) outputs, delivers closed-form beam weights that enforce a distortionless response at each scan direction while globally minimizing sidelobe power. The formulation resolves the main-beam drift caused by the ill-conditioned re-scaling step in iterative Chebyshev tapering, achieving sidelobe levels below $-20$ dB with main-beam peaks within $0.1$° of their commanded angles across all evaluated positions. Mutual coupling between array elements is modeled analytically using the induced-EMF method, yielding a $36\times 36$ impedance matrix whose off-diagonal entries are at most 8.2% of the element self-impedance at the minimum inter-element separation of 2.70 $\lambda$. A closed-form decoupling matrix is applied to the receive manifold prior to LCMV weight computation. Seven simultaneous independent receive beams covering $0$°–$60$° elevation are formed from a single data snapshot. A Scaled Conjugate Gradient neural network classifier, trained on radar-equation-scaled micro-Doppler features following Swerling I–IV radar cross-section (RCS) fluctuation statistics, achieves overall classification accuracy above 85% across five target classes. The five classes comprise two bird-signature classes (SW-I and SW-II), two UAV-signature classes (SW-III and SW-IV), and a clutter class. The design is entirely simulation-based; experimental validation using a sub-array prototype is identified as the primary direction for future work. Full article

Electromagnetic fields (EMFs), increasingly prevalent due to technological advancements, have raised significant concerns regarding their potential biological effects on living organisms. While much attention has focused on human health, growing evidence suggests that EMFs can also affect invertebrates, which play vital ecological roles. This study investigates the biochemical and cell death biomarker responses to EMF exposure for 24 h or 72 h in Parasteatoda tepidariorum. The focus is placed on the 10 MHz frequency, which is relevant to environmental exposure scenarios. Biochemical biomarkers include heat shock proteins (HSP70) and the percentage of apoptotic and living cells in individuals at their embryonic, young and adult stages. Results indicate that exposure to EMFs can induce measurable stress responses at the biochemical level, with variations depending on developmental stage and protective structures. Embryos outside of the egg sac exhibited significantly elevated levels of HSP70 and apoptosis markers compared to those within the sac, suggesting a partial protective effect of the cocoons. Furthermore, differences in biomarker sensitivity were observed across all the developmental stages and increased with prolonged exposure. These findings contribute to the understanding of EMF-induced biological effects in invertebrates and support the use of P. tepidariorum as a model species for environmental electromagnetic pollution. Full article

The Axial Flux Permanent Magnet Synchronous Motor (AFPMSM) has gained significant attention as a core power source for next-generation industrial sectors, including electric vehicles, wind turbines, robot joints, and drone propulsion motors, due to its high power density from a short axial length and large radial dimensions. Despite these structural advantages, cogging torque caused by magnetic interaction between the stator teeth and permanent magnets remains a critical drawback, inducing noise and vibration. While conventional Soft Magnetic Composite (SMC) core methods facilitate 3D flux paths, they suffer from low magnetic permeability, insufficient mechanical strength, and manufacturing complexity. To address these issues, this study proposes a stepped structure model utilizing electrical steel sheets to effectively reduce cogging torque. This structure features radial stacking of identical electrical steel sheets with varying widths, where each layer’s center is incrementally shifted in the rotational direction. This configuration achieves an effect analogous to continuous skewing without specialized 3D machining. To validate the proposed design, 3D Finite Element Analysis (FEA) was conducted. Results demonstrate that the peak-to-peak cogging torque was reduced to approximately 86% of the conventional model’s value, while maintaining the back-EMF reduction rate within 5%. By presenting a novel skewing technique, this research provides a practical alternative for high-precision and high-power AFPMSM. Full article

Forest plantations, including those of Norway spruce, are increasingly threatened by drought in Central Europe. One of the measures understating this threat might be the use of drought-mitigative additives at planting. The effects of induced water limitation and the application of hydrogel Agrisorb and commercial ectomycorrhizal fungi (EMF) inoculum Ectovit on the development of 2 + 1 spruce seedlings were estimated in this study. The root systems of 2 + 0 seedlings were treated with the additives, along with their spring transplantation into peat-filled pots. The seedlings were then exposed throughout the entire growing season either to full watering (FW)—volumetric soil water content 70%, reduced watering (RW)—water content 40%, periodic watering (PW)—substrate rehydrated to 70% after drying to the wilting point (21%), or remained non-watered (NW). Survival, growth and chlorophyll fluorescence of the seedlings decreased proportionally to the increased drought intensity, while the highest root-to-shoot ratio and EMF colonization of roots occurred under PW and RW, respectively. NW seedlings died after 9 weeks of desiccation, whereas the EMF inoculum prolonged the survival time by one week. Ectomycorrhizas were formed predominantly with native EMF in all the treatments; nevertheless, compared with the uninoculated control, the formation of a treatment-specific EMF root morphotype and increased EMF colonization under PW and RW were observed on the inoculated seedlings. Both the EMF inoculum and the hydrogel increased survival under PW by approximately 15% but did not significantly affect growth, regardless of the watering regime. These results are limited to the experimental conditions and suggest a more dominant effects of the watering regimes compared with the additives tested. Full article

The achievements of regenerative medicine are based on methods of controlling stem cell division and differentiation. Electromagnetic fields stimulate cell differentiation by means of affecting calcium channels and cellular signaling. However, only a small part of the mechanisms underlying electromagnetic field effect on cells has been studied. The prospect of their use in tissue engineering as an addition or alternative to biochemical effects becomes clear in the course of numerous experiments. Electromagnetic stimulation enhances the effect of biochemical differentiation inducers and can cause the secretion of exosomes of special properties, which may serve as a therapeutic tool. For example, it has been shown that EMFs at 15 Hz and 2 mT increased the expression of chondrogenic differentiation markers SOX9 and COL2 in human bone-marrow MSCs by up to 3-fold (based on Parate et al.). Optimizing EMF parameters (e.g., 15–50 Hz, 1–2 mT) for specific cells and pathologies remains a key challenge of the studies in the field of tissue engineering. This review describes the electromagnetic field effect on the chondrogenic and osteogenic differentiation of MSCs of various origins, which is important for the musculoskeletal tissue recovery, as well as on inflammatory diseases in model animals. Full article

The biological effects of radiofrequency electromagnetic fields (RF-EMFs) remain an unresolved scientific issue with important societal relevance, particularly in the context of the global deployment of fifth-generation (5G) wireless technologies. The skin is continuously exposed to both RF-EMFs and ultraviolet (UV) radiation, a well-established inducer of oxidative stress and DNA damage, making it a relevant model for assessing combined environmental exposures. In this study, we investigated whether post-exposure to 5G RF-EMFs (3.5 and 28 GHz) modulates ultraviolet A (UVA)-induced genotoxic stress in human keratinocytes (HaCaT) and murine melanoma (B16) cells. Post-UV RF-EMF exposure significantly reduced DNA damage markers, including phosphorylated histone H2AX (γH2AX) foci formation (by approximately 30–50%) and comet tail moments (by 60–80%), and suppressed intracellular reactive oxygen species (ROS) accumulation (by 56–93%). These effects were accompanied by selective attenuation of p38 mitogen-activated protein kinase (MAPK) phosphorylation (reduced by 55–85%). The magnitude of molecular protection was comparable to that observed with N-acetylcysteine treatment or pharmacological inhibition of p38 MAPK. In contrast, RF-EMF exposure did not reverse UV-induced reductions in cell viability or alterations in cell cycle distribution, indicating that its protective effects are confined to early molecular stress-response pathways rather than downstream survival outcomes. Together, these findings demonstrate that 5G RF-EMFs can facilitate recovery from UVA-induced molecular damage via redox-sensitive and p38-dependent mechanisms, providing mechanistic insight into the interaction between modern telecommunication frequencies and UV-induced skin stress. Full article

This paper proposes that immune delay, beyond immune evasion, is key in the propagation competence of major viral and bacterial infections, and that the dynamics of infection and immune response suggest possibilities for mitigating the ensuing infectious diseases. Recent data show a critical role of neutrophils at various stages of viral and bacterial infections, revealing how early activation of neutrophils could help mitigate infectious diseases. It could prevent the gradual overactivation of subclasses of neutrophils and probably not induce it. In respiratory virus infections, an immune delay of several days allows the development of a high viral load supporting infectivity towards further hosts when a delayed and increased immune response takes place. Virus variants will optimize immune delay towards highest infectivity, supporting pandemic potential. The influenza virus, coronavirus, and several major bacterial infections exhibit such immune delay capability. Recurrent urinary tract infections (rUTI) are common, often associated with the causative uropathogenic E. coli (UPEC) that has this capability, suggesting that immune delay is crucial in the pathogenesis of rUTI and other widespread bacterial infections. Counteracting immune delay, therefore, is a promising approach for mitigating infectious diseases with epidemic and pandemic presence or potential. Previously proven low-frequency electromagnetic field (LF-EMF)-induced neutrophil activation is such an approach. Full article

This paper presents the design, optimization, and validation of a dual three-phase yokeless and segmented armature (YASA) axial flux permanent magnet (AFPM) machine for aerospace actuators. The proposed 12-slot, 10-pole topology employs segmented soft magnetic composite (SMC) stator teeth integrated into an additively manufactured aluminium holder, combining modularity, weight reduction, and improved thermal conduction. A multi-objective optimization process based on 3D finite element analysis (FEA) was applied to balance torque capability and losses. The manufacturable design achieved a peak torque of 28.3 Nm at 1400 rpm and a peak output power of 3.5 kW with an efficiency of 81.6%, while limiting short-circuit currents to 14 Arms. Transient structural simulations revealed that three-phase short circuits induce unbalanced axial forces, exciting rotor wobbling—a phenomenon not previously reported for YASA machines. A prototype was fabricated and tested, with static torque measurements deviating by 8.6% from FEA predictions. By contrast, line-to-line back-EMF and generator-mode power output exhibited larger discrepancies (up to 20%), attributed to the frequency-dependent permeability and localized eddy currents of the SMC stator material introduced during EDM machining. These results demonstrate both the feasibility and the limitations of YASA AFPM machines for aerospace applications. Full article

The proliferation of telecommunication devices in recent decades has resulted in a substantial increase in exposure risk to manmade radiofrequency electromagnetic fields (RF-EMFs) for both animals and plants. The physiological effects of these exposures remain to be fully elucidated. In this study, we measured and analyzed the chlorophyll fluorescence rise kinetics of lettuce plants in the presence of RF-EMFs and after a short drought treatment. The analysis of the fluorescence data was conducted using two different strategies: a conventional JIP test and a novel machine learning-assisted anomaly-detection approach. Our results suggest that exposure to RF-EMFs weakens the plant’s hormetic responses induced by drought treatment, both in terms of the response’s magnitude and its extent. These findings provide further evidence supporting the hypothesis that RF-EMFs interfere with plant stress responses. Full article

Aiming at the transient overcurrent problem faced by doubly-fed induction generators (DFIGs) during continuous voltage fault ride-through, a segmented control strategy based on the rotor side converter (RSC) is proposed. First, through theoretical analysis of the relationship between stator current and transient induced electromotive force (EMF) in each stage of continuous faults, a feedforward control strategy based on the transient component of stator current is proposed. The observable stator current is extracted for its transient component, which is used as a rotor voltage compensation term to effectively counteract the influence of transient EMF. Meanwhile, a fuzzy control algorithm is introduced during the low voltage ride-through (LVRT) stage to dynamically adjust the virtual resistance value, enhancing the system’s damping characteristics. Studies show that this strategy significantly suppresses rotor current spikes in all stages of voltage ride-through. Finally, simulation results verify that the proposed method improves the ride-through performance of DFIG under continuous voltage faults. Full article

Background/Objectives: Angiogenesis is the multistep process of the formation of new blood vessels. It is beneficial in scenarios that require tissue repair and regeneration, such as wound healing, bone fracture repair, and recovery from ischemic injuries like stroke, where new blood vessel formation restores oxygen and nutrient supply to damaged areas. Extremely low-frequency electromagnetic stimulation (ELF-EMS), which involves electromagnetic fields in the frequency range of 0–300 Hz, have been shown to reduce ischemic stroke volume by improving cerebral blood flow and recovery effects that are dependent on eNOS. Based on previous results, we herein explore the effects of ELF-EMS treatment (13.5 mT/10 and 60 Hz) on the activation of angiogenic processes in vitro in homeostatic conditions. Methods: Using human microvascular endothelial cells (HMEC-1), we studied cell proliferation, migration, and tube formation in vitro, as well as nitric oxide production and the effect of calcium and nitric oxide (NO) on these processes. Moreover, blood vessel formation was studied using a chicken chorioallantoic membrane (CAM) assay. Results: Our results showed that ELF-EMS increases proliferation, tube formation, and both the migration and transmigration of these cells, the latter of which was mediated via NO. In turn, calcium inhibition decreased ELF-EMF-induced NO production. Furthermore, ELF-EMS significantly increased blood vessel formation in the CAM assay. Conclusions: Our results indicated that ELF-EMS exposure (13.5 mT/10 and 60 Hz) significantly induces angiogenesis in vitro and in ovo, underscoring its potential application in the treatment of conditions characterized by insufficient blood supply. Full article

Emerging evidence highlights the biological risks associated with electromagnetic fields (EMFs) generated by electronic devices. The toxic effects and mechanisms induced by exposure to EMFs on microglial cells and natural substances that inhibit them are limited to date. Here, we investigated whether exposure to 3.5 GHz EMF radiation, potentially generated by smartphones working in 5G communication or cooking using microwave ovens, affects the growth of BV2 mouse microglial cells and polydeoxyribonucleotide (PDRN), a DNA preparation derived from salmon sperm, inhibits it. Of note, exposure to 3.5 GHz EMF radiation for 2 h markedly inhibited the growth and triggered apoptosis in BV2 cells, characterized by the reduced number of surviving cells, increased genomic DNA fragmentation, increased reactive oxygen species (ROS) levels, and altered phosphorylation and expression levels of JNK-1/2, p38 MAPK, ERK-1/2, eIF-2α, and procaspase-9. Pharmacological inhibition studies revealed that JNK-1/2 and p38 MAPK activation and ROS generation were crucial for 3.5 GHz EMF-induced BV2 cytotoxicity. Of interest, PDRN effectively countered these effects by inhibiting the activation of JNK-1/2, p38 MAPK, and caspase-9, and the production of ROS, although it did not affect eIF-2 phosphorylation. In conclusion, this study is the first to report that PDRN protects against 3.5 GHz EMF-induced toxicities in BV2 microglial cells, and PDRN’s protective effects on 3.5 GHz EMF-induced BV2 cytotoxicity are mediated primarily by modulating ROS, JNK-1/2, p38 MAPK, and caspase-9. Full article