Unlike the role of mesenchymal stem cells (MSCs) in regenerative medicine, their application in cell therapy can be complicated by factors such as a reduction in the proliferation potential, ...senescent tendency of MSCs to expand, and an age-dependent decline in their number and functions. It was shown that there is an association between exposure to electromagnetic fields (EMFs) and response to stress, cell proliferation, aging, and cell death. Furthermore, the zinc ion, as an essential trace element, was reported to be involved in the regulation of the growth and cell proliferation. In this report, ratadipose tissue-derived mesenchymal stem cells (rADSCs) were randomly divided into four groups—group I (control without any ZnSO
4
and EMF); group II (ZnSO
4
treatment without EMF exposed); group III (EMF exposed without ZnSO
4
); and group ІV (EMF exposed with ZnSO
4
)—to evaluate whether 0.14 μg/ml Zinc sulfate (ZnSO
4
) could affect cell proliferation of rADSCs under extremely low frequency-electromagnetic field (ELF-EMF). The methyl thiazoltetrazolium (MTT) method was used to determine the cell proliferation of rADSCs following exposure to ELF-EMF in the presence of ZnSO
4
. The immunocytochemistry method as well as flow-cytometry was used to identify the cell surface markers. Next, oil red O, alizarin red, toluidine blue, and cresyl violet staining was done to evaluate the adipogenic, osteogenic, chondrogenic, and neurogenic differentiation of rADSCs as the pluripotent capacity of rADSCs, respectively. The results showed that an exposure to ELF-EMF caused a decrease in the proliferation of rADSCs. However, the ZnSO
4
supplementation significantly increased the cell proliferation of ELF-EMF-exposed rADSCs. In addition, in the presence of 0.14 μg/ml ZnSO
4
, rADSCs appeared to be growing faster than the control group and ZnSO
4
significantly decreased the doubling time of ELF-EMF-exposed rADSCs. It seems that ZnSO
4
would be a good element to induce the cell proliferation of ELF-EMF-exposed rADSCs.
The aim of the present study was to determine the effect of an electromagnetic field (EMF) of value typically recorded in the vicinity of submarine cables (50 Hz, 1 mT) on the behavior and ...bioenergetics of the polychaete Hediste diversicolor. No avoidance or attraction behavior to EMF was shown, but the burrowing activity of H. diversicolor was enhanced in EMF treatment, indicating a stimulating effect on bioturbation potential. The polychaete maintained a positive energy balance and high amount (85% of assimilated energy) of energy available for individual production (scope for growth) after exposure to EMF. Food consumption and respiration rates were not affected but ammonia excretion rate was significantly reduced in EMF-exposed animals compared to the control conditions (geomagnetic field). The mechanisms behind this effect remain, however, unclear. This is the first study demonstrating the effects of environmentally realistic EMF value on the behavior and physiology of marine invertebrates, thus there is a need for more research.
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•Effects of 50 Hz 1 mT electromagnetic field (EMF) on H. diversicolor were assessed.•H. diversicolor did not exhibit avoidance or attraction behavior to EMF.•Exposure to EMF increased the sediment reworking activity of H. diversicolor.•H. diversicolor maintained a positive energy balance after exposure to EMF.•EMF significantly decreased the ammonia excretion rate of H. diversicolor.
An in situ (internal) electric field is used as a dosimetric quantity for human protection from low-frequency electromagnetic fields (lower than 5 MHz) under international safety ...standard/;guidelines. The IEEE standard uses a homogenous elliptical cross section to derive external field strength corresponding to an in situ field strength, while the International Committee on Non-Ionizing Radiation Protection (ICNIRP) guidelines use anatomical models to relate them. In the latter, "the 99th percentile value of the in situ electric field averaged over the cube of its side length of 2 mm" is used to represent the maximum in situ electric field. This metric was introduced to suppress computational artifacts that are inherent when using voxelized anatomical models, in which curved boundaries are discretized with a stair-casing approximation. To suppress the error, a few schemes have been proposed for treating the computational artifacts. In this study, the various schemes to suppress the artifacts are reviewed. Subsequently, a postprocessing method for determining the appropriate maximum in situ field strength is proposed. The performance of the proposed scheme is first verified by comparison with an analytical solution in a multilayered sphere. The method is then applied for different exposure scenarios in anatomically realistic human models where the volume under computation is also considered.
A high-intensity pulsed electromagnetic field (HI-PEMF) is a non-invasive and non-contact delivery method and may, as such, have an advantage over gene electrotransfer mediated by conventional ...electroporation using contact electrodes. Due to the limited number of in vitro studies in the field of gene electrotransfection by HI-PEMF, we designed experiments to investigate and demonstrate the feasibility of such a technique for the non-viral delivery of genetic material into cells in vitro. We first showed that HI-PEMF causes DNA adsorption to the membrane, a generally accepted prerequisite step for successful gene electrotransfection. We also showed that HI-PEMF can induce gene electrotransfection as the application of HI-PEMF increased the percentage of GFP-positive cells for two different combinations of pDNA size and concentration. Furthermore, by measuring the uptake of larger molecules, i.e., fluorescently labelled dextrans of three different sizes, we showed endocytosis to be a possible mechanism for introducing large molecules into cells by HI-PEMF.
In electromagnetic field subdomain analysis, the dimension of the coefficient matrix is the main factor affecting the solution speed. To further improve the solution efficiency, this article takes an ...axial-flux induction planar motor that compensates tangential forces generated by tilting of deployable mechanism in spacecraft ground test as the research object and proposes an improved subdomain (IP-SDM) solution model based on reduced order coefficient matrix. Using the equivalent current method, the reduced order coefficient matrix is realized by reducing the number of subdomain layers. The effect of eddy current is considered in the solution process, and the air gap magnetic field distribution and electromagnetic force under sinusoidal current excitation are calculated. Compared with the traditional subdomain methods, the solution speed of the IP-SDM model has been improved. To further prove the efficiency of the proposed method, the air gap magnetic field distribution and horizontal electromagnetic force are investigated by changing the parameters affecting the eddy current. Finally, the accuracy of the proposed IP-SDM model is verified by finite element analysis and prototype experiments.
•Applies a dynamic bit-vector data structure using an electromagnetic field approach.•Makes adjustments to increase processing speed and reduce solution storage space.•Hides sensitive association ...rules simultaneously.•Proposes a solution for the reduction of non-sensitive information.•Evaluates the proposed method based on both real-world and synthetic datasets.
Hiding the association rules is one of the methods used to protect sensitive information in data-mining processes. Its goal is to transform the original dataset so that the support for, or the reliability of, sensitive rules is reduced below the minimum threshold. Then these sensitive rules cannot be exploited, while the rules that are non-sensitive can still be exploited normally. Many methods have been proposed for hiding the association rules. However, most of these methods are very slow and consume a large amount of storage space. Consequently, they are not suitable when mining large datasets. Recently, the electromagnetic field optimization (EFO4ARH) method was proposed, and it was found to hide the sensitive association rules better than the other methods. To increase mining efficiency further, this paper proposes a new workaround called EFODBV4ARH. This technique applies a dynamic bit vector data structure in combination with the electromagnetic field optimization method. Experimental results indicate that EFODBV4ARH is significantly more efficient than EFO4ARH.
In this paper the photobiomodulation on isolated mitochondria of bovine liver is studied as a thermodynamic process of conversion of energy. This analysis is conducted by considering a particular ...set-up for the photobiomodulation experiments of interest. It allows, in particular, the computation of the electromagnetic field and the related energetic quantities in the stimulated organelles. The measurements of the excess of biochemical power density produced by the illuminated mitochondria are performed at regular time intervals after the experiments. The calculations and the measurements finally allow us to obtain the first results on the efficiency of the process of conversion of electromagnetic energy into excess of biochemical energy released by the isolated organelles.
Nowadays, tissue engineering by using stem cells in combination with scaffolds and bioactive molecules has made significant contributions to the regeneration of damaged bone tissues. Since the usage ...of bioactive molecules including, growth factors to induce differentiation is safety limited in clinical applications, and it has also been previously observed that extremely low frequency pulsed electromagnetic fields (PEMF) can be effective in the enhancement of proliferation rate and osteogenic differentiation of stem cells, the aim of this study was investigating the osteoinductive potential of PEMF in combination with Poly(caprolactone) (PCL) nanofibrous scaffold. To achieve this aim, Adipose‐derived mesenchymal stem cells (ADSCs) isolated and characterized and then osteogenic differentiation of them was investigated after culturing on the surface of PCL scaffold under treatments of PEMF, PEMF plus osteogenic medium (OM) and OM. Analysis of common osteogenic markers such as Alizarin red staining, ALP activity, calcium content and four important bone‐related genes in days of 7, 14, and 21 confirmed that the effects of PEMF on the osteogenic differentiation of ADSCs are very similar to the effects of osteogenic medium. Thus, regarding the immunological concerns about the application of bioactive molecules for tissue engineering, PEMF could be a good alternative for osteogenic medium. Although, results were showed a synergetic effect for simultaneous application of PEMF and PCL scaffold in the osteogenesis process of ADSCs. Taking together, ADSCs‐seeded PCL nanofibrous scaffold in combination with PEMF could be a great option for use in bone tissue engineering applications.
Tissue engineering (stem cells in combination with scaffolds and bioactive molecules) has made significant contributions to the damaged bone regeneration. PEMF can be effective in the enhancement of proliferation rate and osteogenic differentiation of stem cells. ADSCs‐seeded PCL nanofibers in combination with PEMF could be a great option for use in bone tissue engineering applications.
•Daily 3 min SPEMF exposure significantly reversed bone loss of osteopenic mice in 6 weeks.•Daily 8 h PEMF exposure significantly increased BMD of osteopenic mice in 8 weeks.•Daily 3 min SPEMF ...restored the bone mass of osteopenic mice to the levels of healthy mice in 12 weeks.•SPEMF appears to be more therapeutic than PEMF in the treatment of osteopenia.
Pulsed electromagnetic fields (PEMFs) have been proposed to treat bone loss. However, time-consuming is the main complaint. A time-saving and effective treatment is of expectation. Previously, we showed a 3 min daily of single pulsed electromagnetic field (SPEMF) accelerated bone formation of long bone defect in mice. Here we compared the effect of SPEMF with PEMF for treating denervation/disuse osteopenic mice.
Healthy mice were divided into 3 groups: intact mice (INT), INT + PEMF, and INT + SPEMF. Induced osteopenic mice were divided to osteopenia (IOP), IOP + PEMF, and IOP + SPEMF groups. The PEMF treated groups were subjected to daily 8 h PEMF(15 Hz, 18 G) exposure, while SPEMF treated groups were daily 3 min SPEMF(0.2 Hz, 1 T) exposure. BMD was evaluated every two weeks during the 12 weeks of treatment. Microarchitecture was evaluated on week 12.
SPEMF significantly reversed bone loss in IOP mice as early as 6 weeks post-treatment, while PEMF reversed bone loss after 8 weeks. Bone volume was significantly increased in the IOP + PEMF and IOP + SPEMF group. Besides, bone volume and trabecular number of IOP + SPEMF mice were restored to the levels of INT mice in 12 weeks. Our finding suggests SPEMF increased BMD and restored microarchitecture of disuse osteopenic mice to healthy level.
