Cellular ATP levels are affected by moderate and strong static magnetic fields

Effects of Short-, Medium-, and Long-Term Treatment Using Photobiomodulation Therapy Combined with Static Magnetic Field in Aging Rats

(1) Background: We investigated the detrimental and protective effects of short-, medium, and long-term treatment with different doses of photobiomodulation therapy combined with static magnetic field (PBMT-sMF) during the aging process. (2) Methods: Rats were treated for 15, 30, and 60 weeks with 1, 3, 10, and 30 J of PBMT-sMF or a placebo control. In addition, eight young rats were not subjected to any procedure or treatment and were euthanized at six weeks old. Skin, muscle, bone, kidney, liver, and blood samples were analyzed. (3) Results: No differences between the groups in the morphology of the skin, muscle, and bone was observed. Glutamic pyruvic transaminase levels were increased in the placebo group after 30 and 60 weeks. Glutamic oxaloacetic transaminase levels were also increased in the placebo group after 30 weeks. An increase in creatinine in the PBMT-sMF 3, 10, and 30 J groups compared with that in the young control group was observed. No significant difference in urea levels between the groups was noted. Vascular endothelial growth factor increased in the PBMT-sMF 10 and 30 J groups after 15 weeks of treatment and in the PBMT-sMF 3 J after 60 weeks. Finally, vascular endothelial growth factor decreased in the PBMT-sMF 30 J group after 30 weeks of treatment. (4) Conclusions: PBMT-sMF did not have detrimental effects on the skin, muscle, bone, kidney, or liver after short-, medium-, and long-term treatments in aging rats. In addition, PBMT-sMF may have protective effects on the muscle tissue in aging rats after short- and long-term treatment.

Intermittent Theta Burst Stimulation Attenuates Cognitive Deficits and Alzheimer's Disease-Type Pathologies via ISCA1-Mediated Mitochondrial Modulation in APP/PS1 Mice

Intermittent theta burst stimulation (iTBS), a time-saving and cost-effective repetitive transcranial magnetic stimulation regime, has been shown to improve cognition in patients with Alzheimer's disease (AD). However, the specific mechanism underlying iTBS-induced cognitive enhancement remains unknown. Previous studies suggested that mitochondrial functions are modulated by magnetic stimulation. Here, we showed that iTBS upregulates the expression of iron-sulfur cluster assembly 1 (ISCA1, an essential regulatory factor for mitochondrial respiration) in the brain of APP/PS1 mice. In vivo and in vitro studies revealed that iTBS modulates mitochondrial iron-sulfur cluster assembly to facilitate mitochondrial respiration and function, which is required for ISCA1. Moreover, iTBS rescues cognitive decline and attenuates AD-type pathologies in APP/PS1 mice. The present study uncovers a novel mechanism by which iTBS modulates mitochondrial respiration and function via ISCA1-mediated iron-sulfur cluster assembly to alleviate cognitive impairments and pathologies in AD. We provide the mechanistic target of iTBS that warrants its therapeutic potential for AD patients.

Mechanisms of magnetic sensing and regulating extracellular electron transfer of electroactive bacteria under magnetic fields

Electroactive bacteria can display notable plasticity in their response to magnetic field (MF), which prompted bioelectrochemical system as promising candidates for magnetic sensor applications. In this study, we explored the sensing and stimulatory effect of MF on current generation by Geobacter sulfurreducens, and elucidated the related molecular mechanism at the transcriptomic level. MF treatment significantly enhanced electricity generation and overall energy efficiency of G. sulfurreducens by 50 % and 22 %, respectively. The response of current to MFs was instantaneous and reversible. Cyclic voltammetry analysis of the anode biofilm revealed that the redox couples changed from -0.31 to -0.39 V (vs. Ag/AgCl), suggesting that MFs could alter electron transfer related components. Differential gene expression analysis further verified this hypothesis, genes associated with electron transfer were upregulated in G. sulfurreducens under MF treatment relative to the control group, specifically, genes encoding periplasmic c-type cytochromes (ppcA and ppcD), outer membrane cytochrome (omcF, omcZ, omcB), pili (pilA-C, pilM, and pilV2), and ribosome. The enhanced bacterial extracellular electron transfer process was also linked to the overexpression of the NADH dehydrogenase I subunit, the ABC transporter, transcriptional regulation, and ATP synthase. Overall, our findings shed light on the molecular mechanism underlying the effects of magnetic field stimuli on EAB and provide a theoretical basis for its further application in magnetic sensors and other biological system.

Biophysical mechanisms underlying the effects of static magnetic fields on biological systems

With the widespread use of static magnetic fields (SMFs) in medicine, it is imperative to explore the biological effects of SMFs and the mechanisms underlying their effects on biological systems. The presence of magnetic materials within cells and organisms could affect various biological metabolism and processes, including stress responses, proliferation, and structural alignment. SMFs were generally found to be safe at the organ and organism levels. However. human subjects exposed to strong SMFs have reported side effects. In this review, we combined the magnetic properties of biological samples to illustrate the mechanism of action of SMFs on biological systems from a biophysical point of view. We suggest that the mechanisms of action of SMFs on biological systems mainly include the induction of electric fields and currents, generation of magnetic effects, and influence of electron spins. An electrolyte flowing in a static magnetic field generates an induced current and an electric field. Magnetomechanical effects include orientation effects upon subjecting biological samples to SMFs and movement of biological samples in strong field gradients. SMFs are thought to affect biochemical reaction rates and yields by influencing electron spin. This paper helps people how can harness the favorable biological effects of SMFs.

Study on the advanced nitrogen removal under low temperature by biofilm on weak magnetic carriers

The advanced nitrogen removal under low temperature is inhibited because of reduction of the microbial activity. Packed bed reactors filled with different magnetic carriers (0, 0.3, 0.6, 0.9 mT) were constructed to enhance advanced denitrification under low temperature (5 ℃). Results showed that 0.3 and 0.9 mT carriers significantly improved denitrification, indicating the "window" effect. Total nitrogen removals were increased by 6.96% and 8.25%, and NO₂^- accumulation decreased by 25.70% and 13.90% in 0.3 and 0.9 mT reactors, respectively. Analysis of enzyme activity and electron transport chain showed that 0.3 mT carrier mainly increased NIR activity by improving compound III and cytC abundance while 0.9 mT carrier mainly increased NAR activity by improving compound I and NADH abundance, indicating different pathways. Similar microbial community in 0.3 and 0.9 mT reactors were revealed. Overall, weak magnetic carriers can be used to enhance advanced nitrogen removal under low temperature.

The respiratory cytotoxicity of typical organophosphorus flame retardants on five different respiratory tract cells: Which are the most sensitive one?

Triphenyl phosphate (TPHP) is a frequently used flame retardant and indoor semi-volatile pollutant exposing humans with endocrinal disrupting effects. However, its respiratory tract toxicity remains unclear. Herein, we mainly focused on exploring the cytotoxicity of TPHP to the cells from five different parts of the human respiratory tract (from top to bottom): human nasal epithelial (HNEpC) cells, human bronchial epithelial (16HBE) cells, normal nasopharyngeal epithelial (NP69) cells, human lung epithelial cells (Beas-2B) cells, and human lung fibrocells (HFL1 cells) cells. The cell viability, micronucleus induction, endoplasmic reticulum stress gene, intracellular Ca²⁺ concentration, mitochondrial membrane potential (MMP) were investigated in short-term as well as extended exposure of TPHP. HFL1 and HNEpC cells were found to be irreversible damage, while other three type cells achieved homeostasis through self-rescue. Moreover, expression of downstream genes of Nrf2 signaling pathway were upregulated for 1.3-7.0 times and glutathione detoxification enzyme activity changed for 2-10 (U/mg protein) in HNEpC cells. Furthermore, the vascular endothelial growth factor (VEGF), a disease-related factor, increased 1.0-3.5-fold in HNEpC cells. RNA-sequencing results suggested that protein linkage recombination, molecular function regulation and metabolic processes signal pathway were all affected by TPHP exposure in HNEpC. This is a first report to compare respiratory cytotoxicity in whole human respiratory tract under OPFR exposure and found HNEpC cells were the most sensitive target of TPHP. Molecular biological mechanisms uncovered that TPHP exposure in HNEpC can induce the activation of MAPK signal pathway and demonstrate potential respiratory growth differentiation and stress disorder in human nasal cells upon TPHP exposure.

Moderate intensity of static magnetic fields can alter the avoidance behavior and fat storage of Caenorhabditis elegans via serotonin

Man-made static magnetic fields (SMFs) widely exist in human life as a physical environmental factor. However, the biological responses to moderate SMFs exposure and their underlying mechanisms are largely unknown. The present study was focused on exploring the nervous responses to moderate-intensity SMFs at 0.5 T and 1 T in Caenorhabditis elegans (C. elegans). We found that SMFs at either 0.5 T or 1 T had no statistically significant effects on the locomotor behaviors, while the 1 T magnetic field increased pharyngeal pumping. The avoidance behavior of the pathogenic Pseudomonas aeruginosa was greatly decreased in either 0.5 T or 1 T SMFs exposed nematodes, and the learning index was reducede from 0.52 ± 0.11 to 0.23 ± 0.17 and 0.16 ± 0.11, respectively. The total serotonin level was increased by 17.08% and 16.45% with the treatment of 0.5 T and 1 T SMF, compared to the control group; however, there were minimal effects of SMFs on other three neurotransmitters including choline, γ-aminobutyric acid (GABA), dopamine. RT-qPCR was used to further investigate the expression of serotonin-related genes, including rate-limiting enzymes, transcription factors and transport receptors. The expression levels of tph-1 and unc-86 genes were increased by SMF exposure, while those of ocr-2, osm-9, ser-1 and mod-1 genes were decreased. With the staining of lipid in either wild-type N2 or tph-1 mutants, we found that 0.5 T and 1 T SMFs decreased fat storage in C. elegans via serotonin pathway. Our study demonstrated that moderate-intensity SMFs induced neurobehavioral disorder and the reduction of fat storage by disturbing the secretion of serotonin in C. elegans, which provided new insights into elucidating nervous responses of C. elegans to moderate-intensity SMFs.

Photobiomodulation Therapy Combined with Static Magnetic Field (PBMT–SMF) on Spatiotemporal and Kinematics Gait Parameters in Post-Stroke: A Pilot Study

Background: Gait deficit is a major complaint in patients after stroke, restricting certain activities of daily living. Photobiomodulation therapy combined with a static magnetic field (PBMT-SMF) has been studied for several diseases, and the two therapies are beneficia. However, their combination has not yet been evaluated in stroke. Therefore, for PBMT–SMF to be used more often and become an adjunctive tool in the rehabilitation of stroke survivors at physical therapy rehabilitation centers and clinics, some important aspects need to be clarified. Purpose: This study aimed to test different doses of PBMT–SMF, to identify the ideal dose to cause immediate effects on the spatiotemporal and kinematic variables of gait in post-stroke patients. Methods: A randomized, triple-blinded, placebo-controlled crossover pilot study was performed. A total of 10 individuals with hemiparesis within 6 months to 5 years since the occurrence of stroke, aged 45–60 years, were included in the study. Participants were randomly assigned and treated with a single PBMT–SMF dose (sham, 10 J, 30 J, or 50 J) on a single application, with one dose per stage at 7-day intervals between stages. PBMT–SMF was applied with a cluster of 12 diodes (4 of 905 nm laser, 4 of 875 nm LEDs, and 4 of 640 nm LEDs, SMF of 35 mT) at 17 sites on both lower limbs after baseline evaluation: plantar flexors (2), knee extensors (9), and flexors (6). The primary outcome was self-selected walking speed, and the secondary outcomes were kinematic parameters. Gait analysis was performed using SMART-D 140^® and SMART-D INTEGRATED WORKSTATION^®. The outcomes were measured at the end of each stage after the single application of each PBMT–SMF dose tested. Results: No significant differences (p > 0.05) in spatiotemporal variables were observed between the different doses, compared with the baseline evaluation. However, differences (p < 0.05) were observed in the kinematic variable of the hip in the paretic and non-paretic limbs, specifically in the minimum flexion/extension angulation during the support phase (HMST–MIN) in doses 10 J, 30 J, and 50 J. Conclusions: A single application of PBMT–SMF at doses of 10 J, 30 J, and 50 J per site of the lower limbs did not demonstrate positive effects on the spatiotemporal variables, but it promoted immediate effects in the kinematic variables of the hip (maximum and minimum flexion/extension angulation during the support phase) in the paretic and non-paretic limbs in post-stroke people.

Electromagnetic stimulation increases mitochondrial function in osteogenic cells and promotes bone fracture repair

Bone fracture is a growing public health burden and there is a clinical need for non-invasive therapies to aid in the fracture healing process. Previous studies have demonstrated the utility of electromagnetic (EM) fields in promoting bone repair; however, its underlying mechanism of action is unclear. Interestingly, there is a growing body of literature describing positive effects of an EM field on mitochondria. In our own work, we have previously demonstrated that differentiation of osteoprogenitors into osteoblasts involves activation of mitochondrial oxidative phosphorylation (OxPhos). Therefore, it was reasonable to propose that EM field therapy exerts bone anabolic effects via stimulation of mitochondrial OxPhos. In this study, we show that application of a low intensity constant EM field source on osteogenic cells in vitro resulted in increased mitochondrial membrane potential and respiratory complex I activity and induced osteogenic differentiation. In the presence of mitochondrial inhibitor antimycin A, the osteoinductive effect was reversed, confirming that this effect was mediated via increased OxPhos activity. Using a mouse tibial bone fracture model in vivo, we show that application of a low intensity constant EM field source enhanced fracture repair via improved biomechanical properties and increased callus bone mineralization. Overall, this study provides supporting evidence that EM field therapy promotes bone fracture repair through mitochondrial OxPhos activation.

Effect of High Static Magnetic Field (2 T-12 T) Exposure on the Mineral Element Content in Mice

Relative stability of mineral elements in tissues is necessary for health. High static magnetic fields (HiSMFs) have been widely used in biomedical research and industry. However, the bioeffect of HiSMFs on animals is still unclear. In this study, we investigated the effects of HiSMF exposure on the levels of Mg, Fe, Zn, Ca, and Cu in the main organs of mice. The 8-week male C57BL/6 mice were treated by 2-4 T, 6-8 T, 10-12 T HiSMFs for 28 days. The mass fractions of Mg, Fe, Zn, Ca, and Cu in the liver, brain, kidney, and heart in mice were respectively measured by atomic absorption spectroscopy, and used to evaluate mineral element content in tissues. The 2-4 T HiSMF exposure has increased the Mg, Fe, and Ca content in the kidney, as well as the Zn content in the brain. The 6-8 T HiSMF exposure has increased the Zn level in the liver; Mg, Fe, and Ca levels in the kidney; and Fe level in the heart, while the Zn in the kidney, and Zn and Ca in the heart was decreased by 6-8 T HiSMF exposure. For the 10-12 T HiSMF exposure, the Mg in the kidney, the Fe in the liver and kidney, and Cu in the brain have been increased significantly. However, the Zn in the kidney and the Ca in the brain and the heart were reduced by 10-12 T HiSMF exposure. The HiSMF exposure for 28 days can alter the Mg, Fe, Zn, Ca, and Cu content in mice, and change with the different magnetic flux density of HiSMFs (2-4 T, 6-8 T, 10-12 T), elements, and organ types.

Effects of Photobiomodulation Therapy Combined with Static Magnetic Field in Severe COVID-19 Patients Requiring Intubation: A Pragmatic Randomized Placebo-Controlled Trial

Purpose

We aimed to investigate the effects of photobiomodulation therapy combined with static magnetic field (PBMT-sMF) on the length of intensive care unit (ICU) stay and mortality rate of severe COVID-19 patients requiring invasive mechanical ventilation and assess its role in preserving respiratory muscles and modulating inflammatory processes.

Patients and Methods

We conducted a prospectively registered, triple-blinded, randomized, placebo-controlled trial of PBMT-sMF in severe COVID-19 ICU patients requiring invasive mechanical ventilation. Patients were randomly assigned to receive either PBMT-sMF or a placebo daily throughout their ICU stay. The primary outcome was length of ICU stay, defined by either discharge or death. The secondary outcomes were survival rate, diaphragm muscle function, and the changes in blood parameters, ventilatory parameters, and arterial blood gases.

Results

Thirty patients were included and equally randomized into the two groups. There were no significant differences in the length of ICU stay (mean difference, MD = −6.80; 95% CI = −18.71 to 5.11) between the groups. Among the secondary outcomes, significant differences were observed in diaphragm thickness, fraction of inspired oxygen, partial pressure of oxygen/fraction of inspired oxygen ratio, C-reactive protein levels, lymphocyte count, and hemoglobin (p < 0.05).

Conclusion

Among severe COVID-19 patients requiring invasive mechanical ventilation, the length of ICU stay was not significantly different between the PBMT-sMF and placebo groups. In contrast, PBMT-sMF was significantly associated with reduced diaphragm atrophy, improved ventilatory parameters and lymphocyte count, and decreased C-reactive protein levels and hemoglobin count.

Trial Registration Number (Clinical Trials.gov)

NCT04386694.

Effects of Photobiomodulation Therapy Combined with Static Magnetic Field in Severe COVID-19 Patients Requiring Intubation: A Pragmatic Randomized Placebo-Controlled Trial

PURPOSE

We aimed to investigate the effects of photobiomodulation therapy combined with static magnetic field (PBMT-sMF) on the length of intensive care unit (ICU) stay and mortality rate of severe COVID-19 patients requiring invasive mechanical ventilation and assess its role in preserving respiratory muscles and modulating inflammatory processes.

PATIENTS AND METHODS

We conducted a prospectively registered, triple-blinded, randomized, placebo-controlled trial of PBMT-sMF in severe COVID-19 ICU patients requiring invasive mechanical ventilation. Patients were randomly assigned to receive either PBMT-sMF or a placebo daily throughout their ICU stay. The primary outcome was length of ICU stay, defined by either discharge or death. The secondary outcomes were survival rate, diaphragm muscle function, and the changes in blood parameters, ventilatory parameters, and arterial blood gases.

RESULTS

Thirty patients were included and equally randomized into the two groups. There were no significant differences in the length of ICU stay (mean difference, MD = -6.80; 95% CI = -18.71 to 5.11) between the groups. Among the secondary outcomes, significant differences were observed in diaphragm thickness, fraction of inspired oxygen, partial pressure of oxygen/fraction of inspired oxygen ratio, C-reactive protein levels, lymphocyte count, and hemoglobin (p < 0.05).

CONCLUSION

Among severe COVID-19 patients requiring invasive mechanical ventilation, the length of ICU stay was not significantly different between the PBMT-sMF and placebo groups. In contrast, PBMT-sMF was significantly associated with reduced diaphragm atrophy, improved ventilatory parameters and lymphocyte count, and decreased C-reactive protein levels and hemoglobin count.

TRIAL REGISTRATION NUMBER CLINICAL TRIALSGOV

NCT04386694.

Application of magnetic fields to wastewater treatment and its mechanisms: A review

Magnetic field (MF) has been applied widely and successfully as an efficient, low-cost and easy-to-use technique to enhance wastewater treatment (WWT) performance. Although the effects of MF on WWT were revealed and summarized by some works, they are still mysterious and complex. This review summarizes the application of MF in magnetic adsorption-separation of heavy metals and dyes, treatment of domestic wastewater and photo-magnetic coupling technology. Furthermore, the mechanisms of MF-enhanced WWT are critically elaborated from the perspective of magnetic physicochemical and biological effects, such as magnetoresistance, Lorentz force, and intracellular radical pair mechanism. At last, the challenges and opportunities for MF application in WWT are discussed. For overcoming the limitations and taking advantages of MFs in WWT, fundamental research of the mechanisms of the application of MFs should be carried out in the future.

Modulation of the Cell Membrane Potential and Intracellular Protein Transport by High Magnetic Fields

To explore cellular responses to high magnetic fields (HMF), we present a model of the interactions of cells with a homogeneous HMF that accounts for the magnetic force exerted on paramagnetic/diamagnetic species. There are various chemical species inside a living cell, many of which may have large concentration gradients. Thus, when an HMF is applied to a cell, the concentration-gradient magnetic forces act on paramagnetic or diamagnetic species and can either assist or oppose large particle movement through the cytoplasm. We demonstrate possibilities for changing the machinery in living cells with HMFs and predict two new mechanisms for modulating cellular functions with HMFs via (i) changes in the membrane potential and (ii) magnetically assisted intracellular diffusiophoresis of large proteins. By deriving a generalized form for the Nernst equation, we find that an HMF can change the membrane potential of the cell and thus have a significant impact on the properties and biological functionality of cells. The elaborated model provides a universal framework encompassing current studies on controlling cell functions by high static magnetic fields. Bioelectromagnetics. 2021;42:27-36. © 2020 Bioelectromagnetics Society.

Does photobiomodulation therapy combined to static magnetic field (PBMT-sMF) promote ergogenic effects even when the exercised muscle group is not irradiated? A randomized, triple-blind, placebo-controlled trial

Background

The direct application of photobiomodulation therapy (PBMT) using low-level laser therapy (LLLT) and light emitting diodes (LEDs) combined with a static magnetic field (sMF) (PBMT-sMF) to target tissues is shown to improve muscle performance and recovery. Studies have reported possible PBMT effects when a local distant to the target tissue is irradiated. Notably, the extent of these effects on musculoskeletal performance and the optimal site of irradiation remain unclear, although this information is clinically important since these aspects could directly affect the magnitude of the effect. Therefore, we investigated the effects of local and non-local PBMT-sMF irradiations on musculoskeletal performance and post-exercise recovery before an eccentric exercise protocol.

Methods

This randomized, triple-blind (participants, therapists and assessors), placebo-controlled trial included 30 healthy male volunteers randomly assigned to the placebo, local, and non-local groups. Active or placebo PBMT-sMF was applied to 6 sites of the quadriceps muscle of both legs. An eccentric exercise protocol was used to induce fatigue. The primary outcome was peak torque assessed by maximal voluntary contraction (MVC). The secondary outcomes were delayed onset muscle soreness (DOMS) measured by visual analogue scale (VAS), muscle injury assessed by serum creatine kinase activity (CK), and blood lactate levels. Evaluations were performed before the eccentric exercise protocol (baseline), as well as immediately after and 1, 24, 48, and 72 h upon protocol completion.

Results

Ten volunteers were randomized per group and analysed for all outcomes. Compared to the placebo and non-local groups, irradiation with PBMT-SMF led to statistically significant improvement (p < 0.05) with regard to all variables in the local group. The outcomes observed in the non-local group were similar to those in the placebo group with regard to all variables.The volunteers did not report any adverse effects.

Conclusion

Our results support the current evidence that local irradiation of all exercised muscles promotes ergogenic effects. PBMT-sMF improved performance and reduced muscle fatigue only when applied locally to muscles involved in physical activity.

Trial registration

NCT03695458. Registered October 04th 2018.

Implant-based direction of magnetic nanoporous silica nanoparticles - influence of macrophage depletion and infection

Implant associated infections are still key problem in surgery. In the present study, the combination of a magnetic implant with administered magnetic nanoporous silica nanoparticles as potential drug carriers was examined in mice in dependence of local infection and macrophages as influencing factors. Four groups of mice (with and without implant infection and with and without macrophage depletion) received a magnet on the left and a titanium control on the right hind leg. Then, fluorescent nanoparticles were administered and particle accumulations at implant surfaces and in inner organs as well as local tissue reactions were analyzed. Magnetic nanoparticles could be found at the surfaces of magnetic implants in different amounts depending on the treatment groups and only rarely at titanium surfaces. Different interactions of magnetic implants, particles, infection and surrounding tissues occurred. The general principle of targeted accumulation of magnetic nanoparticles could be proven.

Does the combination of photobiomodulation therapy (PBMT) and static magnetic fields (sMF) potentiate the effects of aerobic endurance training and decrease the loss of performance during detraining? A randomised, triple-blinded, placebo-controlled trial

Background

Photobiomodulation (PBMT) is a therapy that uses non-ionising forms of light, including low-level lasers and light-emitting diodes (LEDs) that may be capable of modulating cellular activity. Some biological processes may also interact with static magnetic fields (sMF), leading to modulatory effects on cells. Previous studies have verified that the combination of PBMT and sMF (PBMT/sMF) enhances the performance of individuals during aerobic training programs. The detraining period can cause losses in aerobic capacity. However, there is no evidence of the existence of any recourse that can decrease the effects of detraining. We aimed to investigate the effects of PBMT/sMF application during training and detraining to assess the effectiveness of this treatment in reducing the effects of detraining.

Methods

Sixty male volunteers were randomly allocated into four groups— participants who received PBMT/sMF during the training and detraining (PBMT/sMF + PBMT/sMF); participants who received PBMT/sMF during the training and a placebo in the detraining (PBMT/sMF + Placebo); participants who received a placebo during the training and PBMT/sMF in the detraining (Placebo+PBMT/sMF); and participants who received a placebo during the training and detraining (Placebo+Placebo). Participants performed treadmill training over 12 weeks (3 sessions/week), followed by 4 weeks of detraining. PBMT/sMF was applied using a 12-diode emitter (four 905 nm super-pulsed lasers, four 875 nm light-emitting diodes (LEDs), four 640 nm LEDs, and a 35 mT magnetic field) at 17 sites on each lower limb (dosage: 30 J per site). The data were analysed by two-way repeated measures analysis of variance (ANOVA, time vs experimental group) with post-hoc Bonferroni correction.

Results

The percentage of change in time until exhaustion and in maximum oxygen consumption was higher in the PBMT/sMF + PBMT/sMF group than in the Placebo+Placebo group at all time-points (p < 0.05). Moreover, the percentage of decrease in body fat at the 16th week was higher in the PBMT/sMF + PBMT/sMF group than in the Placebo+Placebo group (p < 0.05).

Conclusions

PBMT/sMF can potentiate the effects of aerobic endurance training and decrease performance loss after a 4-week detraining period. Thus, it may prove to be an important tool for both amateur and high-performance athletes as well as people undergoing rehabilitation.

Trial registration

NCT03879226. Trial registered on 18 March 2019.

Acute effects of photobiomodulation therapy and magnetic field on functional mobility in stroke survivors: a randomized, sham-controlled, triple-blind, crossover, clinical trial

Identify the optimal energy delivered with a single application of the combination of photobiomodulation therapy (PBMT) combining different light sources (low-level laser therapy-LLLT and light emitting diode therapy-LEDT) and static magnetic field (sMF) in order to determine the acute effects on functional mobility of stroke survivors. Was conducted a randomized, placebo-controlled, crossover, triple-blind, clinical trial (RCT). Twelve patients were recruited, however ten concluded the study, they were randomly treated with four PBMT/sMF energies (sham-0 J, 10 J, 30 J, and 50 J per site irradiated), with 1-week interval washout between treatments. PBMT/sMF were administered after the pre-intervention (baseline) evaluation and the total energy delivered per site at each treatment was determined based on the results of the randomization procedure. PBMT/sMF were administered in direct contact with the skin and applied with slight pressure to nine sites on the knee extensors, six sites on the knee flexors, and two sites on the plantar flexors' muscles in both lower limbs (bilaterally). The primary outcome measure was the 6-min walk test (6MWT) and the secondary outcome was the Timed Up and Go (TUG) test. Significant improvements were found in the 6MWT test using a total energy of 30 J per site compared with sham (0 J) (p < 0.05) and compared with the baseline evaluation (p < 0.01). And in the TUG test significant improvements were also found using a total energy per site of 30 J per site compared to sham (0 J) and baseline (p < 0.05). PBMT with different light sources (laser and LEDs) and wavelengths in combination with sMF with a total energy per site of 30 J has positive acute effects on functional mobility in stroke survivors.

Rotating magnetic field delays human umbilical vein endothelial cell aging and prolongs the lifespan of Caenorhabditis elegans

The biological effects of magnetic fields are a research hotspot in the field of biomedical engineering. In this study, we further investigated the effects of a rotating magnetic field (RMF; 0.2 T, 4 Hz) on the growth of human umbilical vein endothelial cells (HUVECs) and Caenorhabditis elegans. The results showed that RMF exposure prolonged the lifespan of C. elegans and slowed the aging of HUVECs. RMF treatment of HUVECs showed that activation of adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) was associated with decreased mitochondrial membrane potential (MMP) due to increased intracellular Ca2+ concentrations induced by endoplasmic reticulum stress in anti-aging mechanisms. RMF also promoted the health status of C. elegans by improving activity, reducing age-related pigment accumulation, delaying Aβ-induced paralysis and increasing resistance to heat and oxidative stress. The prolonged lifespan of C. elegans was associated with decreased levels of daf-16 which related to the insulin/insulin-like growth factor signaling pathway (IIS) activity and reactive oxygen species (ROS), whereas the heat shock transcription factor-1 (hsf-1) pathway was not involved. Moreover, the level of autophagy was increased after RMF treatment. These findings expand our understanding of the potential mechanisms by which RMF treatment prolongs lifespan.

6-mT 0-120-Hz magnetic fields differentially affect cellular ATP levels

Adenosine triphosphate (ATP), an indispensable molecule that provides energy for essentially all cellular processes, has been shown to be affected by some magnetic fields (MFs). Although people are frequently exposed to various static and power frequency MFs in their daily lives, the exact effects of these MFs of different frequencies have not been systematically investigated. Here, we tested 6-mT MFs with 0, 50, and 120 Hz for their effects on cellular ATP levels in 11 different cell lines. We found that the 6-mT static magnetic field (SMF) either does not affect or increase cellular ATP levels, while 6-mT 50-Hz MF either does not affect or decrease cellular ATP levels. In contrast, 6-mT 120-Hz MF has variable effects. We examined the mitochondrial membrane potential (MMP) as well as reactive oxygen species (ROS) in four different cell lines, but did not find their direct correlation with ATP levels. Although none of the ATP level changes induced by these three different frequencies of 6-mT MFs are dramatic, these results may be used to explain some differential cellular responses of various cell lines to different frequency MFs.

Acute effects of photobiomodulation therapy (PBMT) combining laser diodes, light-emitting diodes, and magnetic field in exercise capacity assessed by 6MST in patients with COPD: a crossover, randomized, and triple-blinded clinical trial

Chronic obstructive pulmonary disease (COPD) is characterized by dyspnea, as well as musculoskeletal and systemic manifestations. Photobiomodulation therapy (PBMT) with use of low-level laser therapy (LLLT) and/or light-emitting diode therapy (LEDT) is an electrophysical intervention that has been found to minimize or delay muscle fatigue. The aim of this study was to evaluate the acute effect of PBMT with combined use of lasers diodes, light-emitting diodes (LEDs), magnetic field on muscle performance, exercise tolerance, and metabolic variables during the 6-minute stepper test (6MST) in patients with COPD. Twenty-one patients with COPD (FEV₁ 46.3% predicted) completed the 6MST protocol over 2 weeks, with one session per week. PBMT/magnetic field or placebo (PL) was performed before each 6MST (17 sites on each lower limb, with a dose of 30 J per site, using a cluster of 12 diodes 4 × 905 nm super-pulsed laser diodes, 4 × 875 nm infrared LEDs, and 4 × 640 nm red LEDs; Multi Radiance Medical™, Solon, OH, USA). Patients were randomized into two groups before the test according to the treatment they would receive. Assessments were performed before the start of each protocol. The primary outcomes were oxygen uptake and number of steps, and the secondary outcome was perceived exertion (dyspnea and fatigue in the lower limbs). PBMT/magnetic field applied before 6MST significantly increased the number of steps during the cardiopulmonary exercise test when compared to the results with placebo (129.8 ± 10.6 vs 116.1 ± 11.5, p = 0.000). PBMT/magnetic field treatment also led to a lower score for the perception of breathlessness (3.0 [1.0-7.0] vs 4.0 [2.0-8.0], p = 0.000) and lower limb fatigue (2.0 [0.0-5.0] vs 4.0 [0.0-7.0], p = 0.001) compared to that with placebo treatment. This study showed that the combined application of PBMT and magnetic field increased the number of steps during the 6MST and decreased the sensation of dyspnea and lower limb fatigue in patients with COPD.