In recent years, China's manned space program has advanced rapidly, with deep space exploration missions such as manned lunar landing steadily progressing, leading to a significant extension of astronauts' duration in outer space. In this context, the impact of the space magnetic field environment on astronaut health has become increasingly conspicuous. Characterized by its complexity, the spatial magnetic field indirectly regulates the circadian rhythm system by interfering with mitochondrial functions, such as electron transport chain activity, ATP synthesis efficiency, and reactive oxygen species (ROS) balance. This disruption can lead to circadian misalignment, sleep disorders, metabolic dysregulation, and other issues, severely compromising astronauts' physical and mental well-being, as well as mission performance. Currently, researchers have carried out extensive investigations into the influence of the space magnetic environment on circadian rhythms. Nevertheless, due to disparities in magnetic field parameters, exposure durations, and the model organisms employed in experiments, the results have been inconsistent. This review systematically elaborates on ground-based simulation technologies for spatial magnetic field environments and their applications, summarizes the effects of magnetic fields with varying intensities and types on core circadian rhythm biomarkers in model organisms and humans, and explores the underlying molecular and physiological mechanisms of magnetic field-induced circadian rhythm perturbation. This work aims to deepen the understanding of the mechanisms of the space magnetic environment on biological rhythms, and establish a scientific basis for formulating adaptive protective strategies centered on circadian regulation for astronauts, thereby ensuring the successful implementation of long-term deep-space missions.
Circadian Rhythm/physiology* ; Humans ; Magnetic Fields/adverse effects* ; Space Flight ; Animals ; Extraterrestrial Environment

PURPOSETo describe our clinical experience with a system named SureShot? Distal Targeting (Smith & Nephew, Memphis, USA) based on magnetic field presence and discuss our suggestions on this technique.

METHODSWe analysed prospectively 47 patients affected by humeral, tibial or femoral fractures, treated in our institution during a 3-year period of time (August 2010 to September 2013). We considered the following parameters: the time to set up, the time to position a single screw, the effectiveness of the system (drilling ad screwing), the irradiation exposure time during distal locking procedure and surgical complications.

RESULTSA total number of 96 screws were inserted. The mean preparation time of the device was 5.1 min ± 2 min (range 3-10 min). The mean time for single screw targeting was 5.8 min ± 2.3 min (range 4-18 min). No major complications occurred. Only a few locking procedures were needed to be practiced in order to obtain the required expertise with this targeting device.

CONCLUSIONAccording to our results, this device is reliable and valid whenever the correct technique is followed. It is also user friendly, exposes to lower radiation and needs less surgical time compared to relative data from the literature. However, the surgeon should always be aware of how to use the free hand technique in case of malfunctioning of the system.

Bone Screws ; Fracture Fixation, Intramedullary ; adverse effects ; instrumentation ; methods ; Humans ; Magnetic Fields ; Prospective Studies

OBJECTIVETo investigate the bioeffects of extremely low frequency (ELF) magnetic field (MF) (50 Hz, 400 μT) and magnetic nanoparticles (MNPs) via cytotoxicity and apoptosis assays on PC12 cells.

METHODSMNPs modified by SiO₂ (MNP-SiO₂) were characterized by transmission electron microscopy (TEM), dynamic light scattering and hysteresis loop measurement. PC12 cells were administrated with MNP-SiO2 with or without MF exposure for 48 h. Cytotoxicity and apoptosis were evaluated with MTT assay and annexin V-FITC/PI staining, respectively. The morphology and uptake of MNP-SiO₂ were determined by TEM. MF simulation was performed by Ansoft Maxwell based on the finite element method.

RESULTSMNP-SiO₂ were identified as ~20 nm (diameter) ferromagnetic particles. MNP-SiO₂ reduced cell viability in a dose-dependent manner. MF also reduced cell viability with increasing concentrations of MNP-SiO₂. MNP-SiO₂ alone did not cause apoptosis in PC12 cells; instead, the proportion of apoptotic cells increased significantly under MF exposure and increasing doses of MNP-SiO₂. MNP-SiO₂ could be ingested and then cause a slight change in cell morphology.

CONCLUSIONCombined exposure of MF and MNP-SiO₂ resulted in remarkable cytotoxicity and increased apoptosis in PC12 cells. The results suggested that MF exposure could strengthen the MF of MNPs, which may enhance the bioeffects of ELF MF.

Animals ; Apoptosis ; drug effects ; Cell Proliferation ; drug effects ; Magnetic Fields ; adverse effects ; Magnetite Nanoparticles ; toxicity ; Microscopy, Electron, Transmission ; PC12 Cells ; Rats ; Silicon Dioxide

In the past century, there have been many attempts to treat cancer with low levels of electric and magnetic fields. We have developed noninvasive biofeedback examination devices and techniques and discovered that patients with the same tumor type exhibit biofeedback responses to the same, precise frequencies. Intrabuccal administration of 27.12 MHz radiofrequency (RF) electromagnetic fields (EMF), which are amplitude-modulated at tumor-specific frequencies, results in long-term objective responses in patients with cancer and is not associated with any significant adverse effects. Intrabuccal administration allows for therapeutic delivery of very low and safe levels of EMF throughout the body as exemplified by responses observed in the femur, liver, adrenal glands, and lungs. In vitro studies have demonstrated that tumor-specific frequencies identified in patients with various forms of cancer are capable of blocking the growth of tumor cells in a tissue- and tumor-specific fashion. Current experimental evidence suggests that tumor-specific modulation frequencies regulate the expression of genes involved in migration and invasion and disrupt the mitotic spindle. This novel targeted treatment approach is emerging as an appealing therapeutic option for patients with advanced cancer given its excellent tolerability. Dissection of the molecular mechanisms accounting for the anti-cancer effects of tumor-specific modulation frequencies is likely to lead to the discovery of novel pathways in cancer.
Carcinoma, Hepatocellular ; therapy ; Cell Proliferation ; radiation effects ; Electromagnetic Fields ; Humans ; Liver Neoplasms ; therapy ; Magnetic Field Therapy ; adverse effects ; Neoplasms ; diagnosis ; pathology ; therapy ; Radiation Dosage ; Radio Waves ; Thyroid Neoplasms ; therapy ; Treatment Outcome

OBJECTIVE: An ex vivo study found a copper-containing intrauterine device (IUD) to be safe for women undergoing an MRI examination at a 3.0-T field. No significant artifacts caused by the metallic implant were detected. However, there are still no in vivo data about these concerns. The aim of this study was to evaluate 3.0-T magnetic field interactions of copper-containing IUDs in vivo. MATERIALS AND METHODS: Magnetic field interactions and potential adverse events were evaluated in 33 women using a questionnaire-based telephone survey. Two experienced radiologists performed artifact evaluation on MR images of the pelvis. RESULTS: Eighteen patients were eligible for the survey. One patient reported a dislocation of the IUD after the MR examination. All other patients had no signs of field interactions. No IUD-related artifacts were found. CONCLUSION: MRI at 3.0-T is possible for women with copper-containing IUDs. However, consulting a gynecologist to check the correct position of the IUD and exclude complications after an MR examination is highly recommended. High-quality clinical imaging of the female pelvis can be performed without a loss in image quality.
Adult ; Artifacts ; *Copper ; Female ; Hot Temperature ; Humans ; *Intrauterine Devices, Copper/adverse effects ; Magnetic Fields ; Magnetic Resonance Imaging/adverse effects/*methods ; Middle Aged ; Pelvis

OBJECTIVE: To explore the function of outer hair cells and its influencing factors in the workers of occupational exposure to low frequency electric and magnetic fields. METHOD: 502 high-strength LF EMFs-exposed workers were taken as the study subjects. The field intensity indicator and noise analyzer were employed for the examination of the electromagnetic energy intensity and noise value at the working sites. Self-administered questionnaires were adopted. Universal hearing screening by distortion product otoacoustic emission (DPOAE) and pure tone audiometry (PTA) were done. 100 workers who had abnormal POAE were taken as the observation group and 100 workers who had normal DPOAE were taken as the control group. The workers need be confirmed with ABR testing when the pure tone threshold of two consecutive frequencies were above 20 dB HL or DPOAE detection in any frequency did not pass. Multiple factor analysis with logistic regression was performed for the risk factors. RESULT: The average electric power density in job locations was 21-38 KV/m, which was higher than national standard (< 5 kv/m). Average noise-level in job locations was 52-65 dBHL, which was within the standard (< 85 dB(A). Questionnaire presented that low frequency electric and magnetic fields might increase the incidence of headache, insomnia and tinnitus in the observed group. The incidence of abnormal DPOAE was higher in the subjects of the observed group (P < 0.01). At 676, 933, 3616, 5 130, 7253 Hz, the DPOAE amplitudes of the observed group workers were significantly lower than the control group. Multivariate analysis showed that the risk factors of abnormal DPOAE included exposure of EMF, length of service, daily exposure time, conservatory measures might be protective factors. CONCLUSION The changes of DPOAE indicated that the exposure to low frequency electric and magnetic fields had a subtle, discreet and localized impairing effects on outer hair cells. Exposure of low frequency electric and magnetic fields, length of service, daily exposure time might be risk factors, conservatory measures might be protective factors.
Auditory Threshold ; Case-Control Studies ; Electromagnetic Fields ; adverse effects ; Hair Cells, Vestibular ; pathology ; Humans ; Magnetic Fields ; adverse effects ; Male ; Noise ; adverse effects ; Occupational Exposure ; Surveys and Questionnaires

OBJECTIVEHigher levels of exposure to extremely low-frequency magnetic fields (ELF-MF) are associated with a slightly increased risk of childhood leukaemia. Compared with more-developed Western countries, higher exposure levels are evident in the Czech Republic, probably because of the different types of housing. In light of this, we aimed to examine the association between ELF-MF exposure and childhood leukaemia in the Czech Republic.

METHODSWe conducted a paired case-control study. The cases (children with leukaemia) were age- sex- and permanent residence-matched to controls (children without leukaemia). Although this limited potential bias and confounding, it also limited our number of participants.

RESULTSThe matched analyses included 79 case-control pairs. No significant association between ELF-MF exposure and childhood leukaemia was observed for exposures over 0.2 μT (odds ratio [OR]=0.93, confidence interval [CI]=0.45-1.93), 0.3 μT (OR=0.77, CI=0.34-1.75), or 0.4 μT (OR=0.9, CI=0.37-2.22).

CONCLUSIONDespite higher levels of exposure in Middle and Eastern Europe, no indication of an association between ELF-MF exposure and childhood leukaemia was determined. This in contrast to the findings of previous studies conducted in different countries.

Adolescent ; Case-Control Studies ; Child ; Child, Preschool ; Czech Republic ; epidemiology ; Female ; Humans ; Infant ; Leukemia ; epidemiology ; etiology ; Magnetic Fields ; adverse effects ; Male ; Odds Ratio ; Risk Factors

Chromosome Aberrations ; Environmental Exposure ; adverse effects ; Humans ; Magnetic Fields

OBJECTIVETo investigate the effects of sinusoidal magnetic field on isolated sarcoplasmic reticulum (SR) calcium release channel (RyR1) function.

METHODSWith the Ca2+ dynamic spectrum and isotope labeled methods, the Ca2+ release and [(3)H]-Ryanodine binding, the initial rates of NADH oxidation and the production of superoxide of SR exposed to 50 Hz sinusoidal magnetic field (MF) were investigated respectively.

RESULTS0.4 mT, 50 Hz sinusoidal MF exposure for 30 min increased SR Ca2+ release initial rate about 35% from (10.82 +/- 0.89) pmol.mg(-1) pro.s(-1) to (14.69 +/- 1.21) pmol.mg(-1) pro.s(-1); and the [(3)H]-Ryanodine binding by about 15% from (2.13 +/- 0.05) pmol/mg pro to (2.45 +/- 0.07) pmol/mg pro, which regulated by 1 mmol/L NADH with 1 mmol/L NAD+. Meanwhile MF upregulated the rate of NADH oxidation by about 22% from (0.88 +/- 0.11) x 10(-4) FI/s to (1.07 +/- 0.13) x 10(-4) FI/s and upregulated the production of superoxide by about 32% from (0.99 +/- 0.09) x 10(-5) FI/s to (1.31 +/- 0.06) x 10(-5) FI/s.

CONCLUSION0.4 mT sinusoidal MF increases the activity of RyR1 within the low redox potential environment, and promotes NADH oxidase activity and superoxide production.

Animals ; Calcium ; metabolism ; Magnetic Fields ; adverse effects ; Rabbits ; Ryanodine Receptor Calcium Release Channel ; metabolism ; Sarcoplasmic Reticulum ; metabolism ; radiation effects

OBJECTIVETo investigate the relationship among a 50-Hz MF-induced epidermal growth factor receptor (EGFR) clustering, acid sphingomyelinase (A-SMase) and ceramide (CER), and to explore the possible mechanism of receptor clustering.

METHODSHuman amnion (FL) cells were exposed to a 50-Hz sinusoidal magnetic field at 0.4 mT for 15 min with or without imipramine, a specific inhibitor of A-SMase and ceramide pretreatment. EGF treatment served as the positive control and DMSO treatment served as the solvent control. The EGFR was labeled with polyclonal anti-EGFR antibody and the clustering of EGFR was analyzed using immunofluorescence and confocal microscopy. The percentage of cells with EGFR clustering was counted and compared.

RESULTSBoth EGF treatment and 50-Hz MF exposure could induce EGFR clustering. However, the effect could be eliminated by imipramine pretreatment for 4 hours. When FL cells were incubated with ceramide following the imipramine pretreatment for 30 min, EGFR clustering induced by 50-Hz MF exposure could be recovered.

CONCLUSIONEGFR clustering induced by 50-Hz MF depends on A-SMase activity, and ceramide, as the hydrolyzate from A-SMase might participate in the process of EGFR clustering.

Amnion ; cytology ; Cell Line ; Cell Membrane ; metabolism ; radiation effects ; Ceramides ; metabolism ; Epithelial Cells ; metabolism ; radiation effects ; Humans ; Magnetic Fields ; adverse effects ; Receptor, Epidermal Growth Factor ; metabolism ; Sphingomyelin Phosphodiesterase ; metabolism ; physiology