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1.
Journal of Biomedical Engineering ; (6): 1135-1141, 2023.
Article in Chinese | WPRIM | ID: wpr-1008943

ABSTRACT

With the widespread use of electrical equipment, cognitive functions such as working memory (WM) could be severely affected when people are exposed to 50 Hz electromagnetic fields (EMF) for long term. However, the effects of EMF exposure on WM and its neural mechanism remain unclear. In the present paper, 15 rats were randomly assigned to three groups, and exposed to an EMF environment at 50 Hz and 2 mT for a different duration: 0 days (control group), 24 days (experimental group I), and 48 days (experimental group II). Then, their WM function was assessed by the T-maze task. Besides, their local field potential (LFP) in the media prefrontal cortex (mPFC) was recorded by the in vivo multichannel electrophysiological recording system to study the power spectral density (PSD) of θ and γ oscillations and the phase-amplitude coupling (PAC) intensity of θ-γ oscillations during the T-maze task. The results showed that the PSD of θ and γ oscillations decreased in experimental groups I and II, and the PAC intensity between θ and high-frequency γ (hγ) decreased significantly compared to the control group. The number of days needed to meet the task criterion was more in experimental groups I and II than that of control group. The results indicate that long-term exposure to EMF could impair WM function. The possible reason may be the impaired communication between different rhythmic oscillations caused by a decrease in θ-hγ PAC intensity. This paper demonstrates the negative effects of EMF on WM and reveals the potential neural mechanisms from the changes of PAC intensity, which provides important support for further investigation of the biological effects of EMF and its mechanisms.


Subject(s)
Humans , Rats , Animals , Memory, Short-Term/physiology , Electromagnetic Fields/adverse effects , Prefrontal Cortex , Cognition
2.
Chinese Journal of Medical Instrumentation ; (6): 106-109, 2023.
Article in Chinese | WPRIM | ID: wpr-971313

ABSTRACT

Aiming at the increasing application of RFID technology in the medical environment, this study introduces the foreign requirements for RFID immunity test of medical devices, compares them with the current immunity test requirements of medical devices in China, and puts forward the necessity of establishing relevant test specifications in China.


Subject(s)
Radio Frequency Identification Device , Electromagnetic Fields , Radio Waves , Equipment Safety , Technology
3.
Biomedical and Environmental Sciences ; (12): 1045-1058, 2023.
Article in English | WPRIM | ID: wpr-1007880

ABSTRACT

OBJECTIVE@#In this study, the combined effect of two stressors, namely, electromagnetic fields (EMFs) from mobile phones and fructose consumption, on hypothalamic and hepatic master metabolic regulators of the AMPK/SIRT1-UCP2/FOXO1 pathway were elucidated to delineate the underlying molecular mechanisms of insulin resistance.@*METHODS@#Weaned Wistar rats (28 days old) were divided into 4 groups: Normal, Exposure Only (ExpO), Fructose Only (FruO), and Exposure and Fructose (EF). Each group was provided standard laboratory chow ad libitum for 8 weeks . Additionally, the control groups, namely, the Normal and FruO groups, had unrestricted access to drinking water and fructose solution (15%), respectively. Furthermore, the respective treatment groups, namely, the ExpO and EF groups, received EMF exposure (1,760 MHz, 2 h/day x 8 weeks). In early adulthood, mitochondrial function, insulin receptor signaling, and oxidative stress signals in hypothalamic and hepatic tissues were assessed using western blotting and biochemical analysis.@*RESULT@#In the hypothalamic tissue of EF, SIRT1, FOXO 1, p-PI3K, p-AKT, Complex III, UCP2, MnSOD, and catalase expressions and OXPHOS and GSH activities were significantly decreased ( P < 0.05) compared to the Normal, ExpO, and FruO groups. In hepatic tissue of EF, the p-AMPKα, SIRT1, FOXO1, IRS1, p-PI3K, Complex I, II, III, IV, V, UCP2, and MnSOD expressions and the activity of OXPHOS, SOD, catalase, and GSH were significantly reduced compared to the Normal group ( P < 0.05).@*CONCLUSION@#The findings suggest that the combination of EMF exposure and fructose consumption during childhood and adolescence in Wistar rats disrupts the closely interlinked and multi-regulated crosstalk of insulin receptor signals, mitochondrial OXPHOS, and the antioxidant defense system in the hypothalamus and liver.


Subject(s)
Humans , Rats , Animals , Adult , Rats, Wistar , Fructose/metabolism , Catalase , Receptor, Insulin/metabolism , AMP-Activated Protein Kinases/metabolism , Electromagnetic Fields/adverse effects , Sirtuin 1/metabolism , Cell Phone , Phosphatidylinositol 3-Kinases/metabolism , Forkhead Box Protein O1/metabolism , Uncoupling Protein 2
4.
Chinese Journal of Medical Instrumentation ; (6): 442-444, 2023.
Article in Chinese | WPRIM | ID: wpr-982261

ABSTRACT

OBJECTIVE@#To improve the electromagnetic compatibility (EMC) quality of medical devices, improve the efficiency of EMC testing, and promote the speed of market approval.@*METHODS@#The unqualified cases of EMC test items of medical devices in recent years were statistically analyzed, and the reasons of low EMC quality of medical devices were analyzed from the perspective of test.@*RESULTS@#Based on the analysis of the reasons, the suggestions were given from the perspectives of medical device manufacturers and testing organizations.@*CONCLUSIONS@#In order to ensure the quality of EMC of medical devices, medical device manufacturers, regulatory authorities and inspection and testing institutions should strengthen the monitoring and evaluation of medical device electromagnetic compatibility, to ensure the safety of products work together to promote the development of the medical device industry healthily and orderly.


Subject(s)
Electromagnetic Phenomena , Industry , Electromagnetic Fields
5.
Journal of Biomedical Engineering ; (6): 95-102, 2023.
Article in Chinese | WPRIM | ID: wpr-970678

ABSTRACT

The study aims to explore the effect of mesenchymal stem cells-derived exosomes (MSCs-Exo) on staurosporine (STS)-induced chondrocyte apoptosis before and after exposure to pulsed electromagnetic field (PEMF) at different frequencies. The AMSCs were extracted from the epididymal fat of healthy rats before and after exposure to the PEMF at 1 mT amplitude and a frequency of 15, 45, and 75 Hz, respectively, in an incubator. MSCs-Exo was extracted and identified. Exosomes were labeled with DiO fluorescent dye, and then co-cultured with STS-induced chondrocytes for 24 h. Cellular uptake of MSC-Exo, apoptosis, and the protein and mRNA expression of aggrecan, caspase-3 and collagenⅡA in chondrocytes were observed. The study demonstrated that the exposure of 75 Hz PEMF was superior to 15 and 45 Hz PEMF in enhancing the effect of exosomes in alleviating chondrocyte apoptosis and promoting cell matrix synthesis. This study lays a foundation for the regulatory mechanism of PEMF stimulation on MSCs-Exo in inhibiting chondrocyte apoptosis, and opens up a new direction for the prevention and treatment of osteoarthritis.


Subject(s)
Animals , Rats , Apoptosis , Chondrocytes , Electromagnetic Fields , Exosomes/physiology , Mesenchymal Stem Cells/metabolism
6.
Braz. j. biol ; 82: e232525, 2022. tab, graf
Article in English | LILACS, VETINDEX | ID: biblio-1249239

ABSTRACT

The coupling of a ligand with a molecular receptor induces a signal that travels through the receptor, reaching the internal domain and triggering a response cascade. In previous work on T-cell receptors and their coupling with foreign antigens, we observed the presence of planar molecular patterns able to generate electromagnetic fields within the proteins. These planes showed a coherent (synchronized) behavior, replicating immediately in the intracellular domain that which occurred in the extracellular domain as the ligand was coupled. In the present study, we examined this molecular transduction - the capacity of the coupling signal to penetrate deep inside the receptor molecule and induce a response. We verified the presence of synchronized behavior in diverse receptorligand systems. To appreciate this diversity, we present four biochemically different systems - TCR-peptide, calcium pump-ADP, haemoglobin-oxygen, and gp120-CD4 viral coupling. The confirmation of synchronized molecular transduction in each of these systems suggests that the proposed mechanism would occur in all biochemical receptor-ligand systems.


A ligação de um ligante com um receptor molecular induz um sinal que viaja através do receptor, chegando ao domínio interno e disparando uma cascata de resposta. Em trabalhos anteriores em receptores de células T e sua ligação com antígenos estranhos, observamos a presença de padrões moleculares planares capazes de gerar campos eletromagnéticos dentro das proteínas. Esses planos mostraram um comportamento coerente (sincronizado), replicando, instantaneamente, no domínio intracelular o que ocorreu no domínio extracelular, enquanto o ligante era acoplado. No presente estudo, examinamos essa transdução ­ a capacidade de um sinal de acoplamento de penetrar profundamente a molécula receptora e induzir uma resposta. Verificamos a presença de um comportamento coerente em sistemas diversos de receptor-ligante. Para apreciar essa diversidade, apresentamos quatro sistemas bioquímicos diferentes: TCR-peptídeo, ADP-bomba de cálcio, hemoglobina-oxigênio e gp120-CD4 acoplamento viral. A confirmação de transdução molecular sincronizada em cada um desses sistemas sugere que o mecanismo proposto ocorreria em todos os sistemas bioquímicos receptor-ligante.


Subject(s)
Signal Transduction , Electromagnetic Fields , Receptors, Antigen, T-Cell/genetics , Ligands
7.
Journal of Southern Medical University ; (12): 988-996, 2022.
Article in Chinese | WPRIM | ID: wpr-941031

ABSTRACT

OBJECTIVE@#To explore whether the effect of low-frequency pulsed electromagnetic fields (PEMFs) in promoting osteoblast mineralization and maturation is related to the primary cilia, polycystin2 (PC2) and sAC/PKA/CREB signaling pathway.@*METHODS@#We detected the expression levels of PC2, sAC, PKA, CREB and their phosphorylated proteins in primary rat calvarial osteoblasts exposed to 50 Hz 0.6 mT PEMFs for 0, 5, 15, 30, 60, 90, and 120 min. We blocked PC2 function with amiloride hydrochloride and detected the changes in the activity of sAC/PKA/CREB signal pathway and the mineralization and maturation of the osteoblasts. These examinations were repeated in the osteoblasts after specific knockdown of PC2 via RNA interference and were the co-localization of PC2, sAC, PKA, CREB and their phosphorylated proteins with the primary cilia were using immunofluorescence staining. The expressions of PC2 and the signaling proteins of sAC/PKA/CREB pathway were detected after inhibition of primary ciliation by RNA interference.@*RESULTS@#The expression levels of PC2, sAC, p-PKA and p- CREB were significantly increased in the osteoblasts after exposure to PEMFs for different time lengths (P < 0.01). Blocking PC2 function or PC2 knockdown in the osteoblasts resulted in failure of sAC/PKA/CREB signaling pathway activation and arrest of osteoblast mineralization and maturation. PC2, sAC, p-PKA and p-CREB were localized to the entire primary cilia or its roots, but PKA and CREB were not detected in the primary cilia. After interference of the primary cilia, PEMFs exposure no longer caused increase of PC2 expression and failed to activate the sAC/PKA/CREB signaling pathway or promote osteoblast mineralization and maturation.@*CONCLUSION@#PC2, located on the surface of the primary cilia of osteoblasts, can perceive and transmit the physical signals from PEMFs and promote the mineralization and maturation of osteoblasts by activating the PC2/ sAC/PKA/CREB signaling pathway.


Subject(s)
Animals , Rats , Cell Differentiation , Electromagnetic Fields , Osteoblasts , Osteogenesis/genetics , Signal Transduction
8.
Journal of Zhejiang University. Science. B ; (12): 42-57, 2022.
Article in English | WPRIM | ID: wpr-929038

ABSTRACT

Mesenchymal stem/stromal cell (MSC)‍-based therapy has been regarded as one of the most revolutionary breakthroughs in the history of modern medicine owing to its myriad of immunoregulatory and regenerative properties. With the rapid progress in the fields of osteo- and musculoskeletal therapies, the demand for MSC-based treatment modalities is becoming increasingly prominent. In this endeavor, researchers around the world have devised new and innovative techniques to support the proliferation of MSCs while minimizing the loss of hallmark features of stem cells. One such example is electromagnetic field (EMF) exposure, which is an alternative approach with promising potential. In this review, we present a critical discourse on the efficiency, practicability, and limitations of some of the relevant methods, with insurmountable evidence backing the implementation of EMF as a feasible strategy for the clinically relevant expansion of MSCs.


Subject(s)
Cell Differentiation , Cell Proliferation , Electromagnetic Fields , Mesenchymal Stem Cells , Signal Transduction
9.
Chinese Journal of Biotechnology ; (12): 1159-1172, 2022.
Article in Chinese | WPRIM | ID: wpr-927771

ABSTRACT

It is known that low-frequency pulsed electromagnetic fields (PEMFs) can promote the differentiation and maturation of rat calvarial osteoblasts (ROBs) cultured in vitro. However, the mechanism that how ROBs perceive the physical signals of PEMFs and initiate osteogenic differentiation remains unknown. In this study, we investigated the relationship between the promotion of osteogenic differentiation of ROBs by 0.6 mT 50 Hz PEMFs and the presence of polycystin2 (PC2) located on the primary cilia on the surface of ROBs. First, immunofluorescence staining was used to study whether PC2 is located in the primary cilia of ROBs, and then the changes of PC2 protein expression in ROBs upon treatment with PEMFs for different time were detected by Western blotting. Subsequently, we detected the expression of PC2 protein by Western blotting and the effect of PEMFs on the activity of alkaline phosphatase (ALP), as well as the expression of Runx-2, Bmp-2, Col-1 and Osx proteins and genes related to bone formation after pretreating ROBs with amiloride HCl (AMI), a PC2 blocker. Moreover, we detected the expression of genes related to bone formation after inhibiting the expression of PC2 in ROBs using RNA interference. The results showed that PC2 was localized on the primary cilia of ROBs, and PEMFs treatment increased the expression of PC2 protein. When PC2 was blocked by AMI, PEMFs could no longer increase PC2 protein expression and ALP activity, and the promotion effect of PEMFs on osteogenic related protein and gene expression was also offset. After inhibiting the expression of PC2 using RNA interference, PEMFs can no longer increase the expression of genes related to bone formation. The results showed that PC2, located on the surface of primary cilia of osteoblasts, plays an indispensable role in perceiving and transmitting the physical signals from PEMFs, and the promotion of osteogenic differentiation of ROBs by PEMFs depends on the existence of PC2. This study may help to elucidate the mechanism underlying the promotion of bone formation and osteoporosis treatment in low-frequency PEMFs.


Subject(s)
Animals , Rats , Alkaline Phosphatase/metabolism , Electromagnetic Fields , Osteoblasts/metabolism , Osteogenesis/genetics , TRPP Cation Channels/physiology
10.
Rev. cuba. invest. bioméd ; 40(2): e570, 2021. graf
Article in Spanish | LILACS, CUMED | ID: biblio-1347461

ABSTRACT

Introducción: El panorama demográfico en el mundo está cambiando. La población mayor de 60 años es el segmento que está creciendo más rápidamente y en el que las enfermedades del tejido óseo se presentan con más frecuencia, lo que aumenta la demanda de materiales y tecnologías apropiadas para restaurar estos tejidos. Objetivo: Analizar la información que se ha generado sobre el desarrollo de biomateriales compuestos para la reparación ósea, con énfasis en la identificación de las tecnologías emergentes basadas en el uso del campo electromagnético, sus aplicaciones y potencialidades. Métodos: Se consultaron trabajos científicos publicados en libros, revistas, patentes y tesis. El 80 por ciento de la documentación seleccionada pertenece al periodo 2010-2019. Análisis e integración de la información: Los métodos identificados fueron clasificados en cinco grupos: electrodeposición química, ya sea por electrólisis, electroforesis o síntesis electroforética in situ; electroporación; electrohilado; control magnético distal y bioestimulación electromagnética de células y tejidos, directamente o por la introducción de dispositivos que convierten la energía electromagnética en energía mecánica. Conclusiones: Estos métodos permiten la conformación de matrices celulares y acelulares compuestas y, además, dispositivos bioestimuladores con control de los parámetros de construcción y acción, de tal manera, que se logran procesos con mayor grado de reproducibilidad y a la medida de los requerimientos específicos para cada paciente(AU)


Introduction: The global demographic panorama is changing. The population aged over 60 years is the fastest growing segment, as well as the one where bone tissue diseases are most common, increasing the demand of appropriate materials and technologies to restore those tissues. Objective: To analyze the information so far generated about the development of composite biomaterials for bone repair, with an emphasis on the identification of emerging technologies based on the use of the electromagnetic field, its applications and potential. Methods: An analysis was performed of scientific papers published in books, journals, patents and theses. Of the documentation selected, 80 percent was from the period 2010-2019. Data analysis and integration: The methods identified were classified into five groups: chemical electrodeposition, be it by in situ electrophoretic synthesis, electrolysis or electrophoresis; electroporation; electrospinning; distal magnetic control and electromagnetic biostimulation of cells and tissues, either directly or incorporating devices which convert electromagnetic energy into mechanical energy. Conclusions: These methods permit the conformation of composite cellular and acellular matrices as well as biostimulator devices controlling construction and action parameters in such a way that the processes obtained display greater reproducibility and are more in keeping with the specific requirements of each patient(AU)


Subject(s)
Humans , Biocompatible Materials/analysis , Electric Stimulation/methods , Electromagnetic Fields
11.
Rev. Assoc. Med. Bras. (1992) ; 67(2): 282-286, Feb. 2021. tab
Article in English | LILACS | ID: biblio-1287821

ABSTRACT

SUMMARY OBJECTIVE: The aim of this study was to compare the effect of transcutaneous electrical nerve stimulation (TENS), ultrasound (US), and pulsed electromagnetic field (PEMF) combination with TENS and US therapy alone in patients with supraspinatus tear. METHODS: Forty patients were included in this study. The patients were randomly divided into two groups as follows: PEMF (n=20) and Sham (n=20) groups. PEMF was applied to the first group at a frequency of 50 Hz, 25 G intensity, and 20 min/session. The device was turned off while PEMF was applied to the second group. Diathermy (US) and electrotherapy (TENS) were applied to both groups for 10 sessions. Numerical Rating Scale (NRS), University of California-Los Angeles (UCLA) Shoulder Scale, and Shoulder Pain and Disability Index (SPADI) were used as outcome measures. RESULTS: In both groups, there was a significant improvement in the NRS, UCLA Shoulder Scale, and SPADI scores after treatment compared with pretreatment (p<0.05). In the comparison of the difference between the pretreatment and posttreatment measurement values between the groups, no significant difference was found between PEMF and Sham groups according to the NRS (p=0.165), UCLA Shoulder Scale (p=0.141), and SPADI (p=0.839) scores. CONCLUSIONS: In our study, a combination of PEMF therapy with conventional physical therapy modalities was not found to be superior to the conventional therapy alone, and adding it to the routine treatment of symptomatic supraspinatus tear would not provide any additional benefit.


Subject(s)
Humans , Electric Stimulation Therapy , Magnetic Field Therapy , Treatment Outcome , Rotator Cuff , Shoulder Pain/therapy , Electromagnetic Fields
12.
Arq. neuropsiquiatr ; 79(2): 139-148, Feb. 2021. tab, graf
Article in English | LILACS | ID: biblio-1153165

ABSTRACT

ABSTRACT Background: The use of technological devices is growing rapidly, and the use of cell phones increases in parallel. Dependence on technological devices is a particular factor in this increased exposure. Many studies have been performed on this electromagnetic field, but no definite conclusions have been drawn. Objective: The purpose of this research was to investigate exposure to electromagnetic field, cell phone use behaviors, the specific absorption rate (SAR) values, and changes in health occurring after exposure in university students. Methods: A questionnaire was administered to 1,019 volunteer students aged 18-24 years at the Niğde Ömer Halisdemir and Recep Tayip Erdoğan Universities in 2018-2019. The questions were based on a survey of the literature. Results: The students spent an average 4-8 hours per day on their cell phones, and findings such as headache (p=0.002), concentration deficit (p=0.001), tiredness on waking in the morning (p=0.001), hyperactivity (p=0.001), general feeling of fatigue (p=0.001), and lethargy (p=0.001) increased in a statistically significant manner with length of use. Conclusions: Participants exhibited high levels of cell phone use and experienced biological, behavioral, and sleep problems. They also had very little knowledge about specific SAR values, an important criterion concerning cell phones.


RESUMO Introdução: O uso de dispositivos tecnológicos está crescendo rapidamente e o uso de telefone celulares aumenta em paralelo. A dependência de dispositivos tecnológicos é um fator nesse aumento de exposição. Diversos estudos sobre o campo eletromagnético foram realizados, mas nenhuma conclusão definitiva foi alcançada. Objetivo: O objetivo desta pesquisa foi investigar a exposição ao campo eletromagnético, os comportamentos de uso do telefone celular, os valores de absorção específica (specific absorption rate — SAR) dos telefones celulares utilizados e as alterações na saúde ocorridas após a exposição em adolescentes universitários. Métodos: Um questionário foi aplicado a 1.019 alunos voluntários com idades entre 18-24 anos nas universidades Niğde Ömer Halisdemir e Recep Tayip Erdoğan em 2018-2019. As perguntas foram baseadas em um levantamento bibliográfico. Resultados: Os estudantes gastaram em média 4-8 horas por dia em seus celulares, e achados como cefaleia (p=0,002), dificuldade de concentração (p=0,001), cansaço ao acordar pela manhã (p=0,001), hiperatividade (p=0,001), sensação geral de fadiga (p=0,001) e letargia (p=0,001) aumentaram de forma estatisticamente significativa com o tempo de uso. Conclusões: Os participantes exibiram altos níveis de uso de telefone celular e problemas biológicos, comportamentais e de sono. Eles também tinham pouco conhecimento sobre valores específicos de SAR, um critério importante para telefones celulares.


Subject(s)
Humans , Adolescent , Young Adult , Cell Phone , Cell Phone Use , Students , Universities , Electromagnetic Fields/adverse effects
13.
Biomedical and Environmental Sciences ; (12): 593-602, 2020.
Article in English | WPRIM | ID: wpr-828975

ABSTRACT

Objective@#This study aimed to investigate the effect of exposure to a 900 MHz electromagnetic field (EMF) on the cervical spinal cord (CSC) of rats and the possible protective effect of luteolin (LUT) against CSC tissue damage.@*Methods@#Quantitative data were obtained stereological, biochemical, immunohistochemical, and histopathological techniques. We investigated morphometric value, superoxide dismutase (SOD) level, and the expression of high-mobility group box 1 protein molecules, as well as histological changes.@*Results@#The total number of motor neurons in the EMF group significantly decreased in comparison with that in the control group ( < 0.05). In the EMF + LUT group, we found a significant increase in the total number of motor neurons compared with that in the EMF group ( < 0.05). SOD enzyme activity in the EMF group significantly increased in comparison with that in the control group ( < 0.05). By contrast, the EMF+LUT group exhibited a decrease in SOD level compared with the EMF group ( < 0.05).@*Conclusion@#Our results suggested that exposure to EMF could be deleterious to CSC tissues. Furthermore, the protective efficacy of LUT against SC damage might have resulted from the alleviation of oxidative stress caused by EMF.


Subject(s)
Animals , Male , Rats , Antioxidants , Pharmacology , Electromagnetic Fields , Luteolin , Pharmacology , Rats, Wistar , Spinal Cord , Radiation Effects
14.
Chinese Journal of Medical Instrumentation ; (6): 101-107, 2020.
Article in Chinese | WPRIM | ID: wpr-942708

ABSTRACT

The complex electromagnetic field environments in magnetic resonance imaging system(MRI) can have a significant impact on patients carrying implants, the RF heating problems being particularly important. To ensure the safety of the patients, it is necessary to understand the distribution of tissue temperature in the MRI environment and its changes over time. Based on the analysis of tissue temperature rise in MRI, this paper constructs a bird cage coil for generating RF field in MRI system, and constructs ASTM standard/improved phantom and single-cavity pacemaker finite element models, use time-domain finite difference (FDTD) to simulate. Firstly, the correctness of the simulation software and simulation method was validated according to the method of ISO. Then the distribution of the electric field, SAR and temperature field and the temperature change with time were calculated in the environment of 64 MHz, 2 W/kg. The difference in temperature rise with blood heat exchange and no blood heat exchange (standard/improved phantom) was specifically compared. The simulation results show that there are electric field and SAR hotspots near the electrode tip, the wire tail and the case of pacemaker. There are high SAR values on both sides of the phantom, and the shorter the distance from the coil, the higher the SAR. The temperature field distribution is similar to the SAR distribution; the temperature is higher in the area around the end of the wire and the case of pacemaker because the heat accumulation is higher around this area. At the same time, blood heat exchange can reduce the temperature rise to a certain extent.


Subject(s)
Humans , Electromagnetic Fields , Magnetic Resonance Imaging , Models, Theoretical , Phantoms, Imaging , Prostheses and Implants , Temperature
15.
Chinese Journal of Medical Instrumentation ; (6): 302-306, 2020.
Article in Chinese | WPRIM | ID: wpr-828200

ABSTRACT

Concerning on the safety risks caused by electromagnetic interference of patients implanted with high-risk active implantable medical devices in the environment of domestic MUs, this study evaluates and focuses on the requirements of electromagnetic compatibility in domestic and international standards for rail transit vehicles, the main mechanism of risks caused by EMI, the actual measurement of environmental data in MUs and the working performance of various active implantables in the compartment. The test results shows that all kinds of active implantable medical device samples works normally in the CRH2A EMU in China, and there is still a large margin between the measured radiation emission in MU and the limit required by the standards.


Subject(s)
Humans , China , Electromagnetic Fields , Electromagnetic Radiation , Pacemaker, Artificial , Prostheses and Implants
16.
Journal of Biomedical Engineering ; (6): 280-287, 2020.
Article in Chinese | WPRIM | ID: wpr-828169

ABSTRACT

Wireless power transfer (WPT) is a new power transmission way, which can be widely used in electric vehicles and other fields. Its electromagnetic environment must be analyzed to ensure safe application. A low-power wireless power transfer system experimental platform was built, with 25 W receiving power and 47 kHz resonant frequency, which was used to carry out animal experiments. Treatment mice were exposed to environment of wireless power transfer system for 5 h a day and 6 days as one cycle. At the end of every cycle, learning memory behavior of mice were detected in T-shaped maze. The exposure experiment lasted for 12 weeks. Finally, immune parameters, sex hormones and part of organ physiological structure were detected. The results are as follows: as exposure time increased, memory behavior of mice did not change obviously with no statistical difference in sex hormone either ( > 0.05), the concentration of immune factors including tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6) and interleukin-1 beta (IL-1β) significantly increased ( < 0.05), and the structure of some organs showed some changes. The experimental results show that the environment of the wireless power transfer system has no effect on the memory behavior of mice, and has some effect on physiological properties of mice.


Subject(s)
Animals , Mice , Cytokines , Electric Power Supplies , Electricity , Electromagnetic Fields , Gonadal Steroid Hormones , Memory , Wireless Technology
17.
São José dos Campos; s.n; 2020. 70 p. il., graf., tab..
Thesis in Portuguese | LILACS, BBO | ID: biblio-1150925

ABSTRACT

A utilização de estimulação biofísica através da modalidade de campo eletromagnético pulsado (CEMP) para o tratamento de diversas condições no tecido ósseo tem despertado o interesse científico há décadas. Entretanto, a grande variedade nos parâmetros e protocolos utilizados e a divergência de resultados na literatura dificultam o estabelecimento de uma metodologia que seja eficaz no contexto da terapia com implantes osseointegrados. Dessa forma, torna-se importante avaliar o efeito de diferentes tempos de aplicação do CEMP padronizado em diferentes momentos no processo de osseointegração de implantes de titânio inseridos em tíbias de ratos. Para isso, foram utilizados 60 animais (Rattus norvegicus, variação albinus, Wistar), randomizados em três grupos experimentais: controle, teste A (GTA) submetidos por 3 horas de CEMP, e teste B (GTB) com 1 hora de CEMP, sendo que, a exposição ocorreu em 5 dias semanalmente durante o período experimental. Todos os animais receberam implantes em ambas as tíbias, e a aplicação do CEMP ocorreu apenas nos grupos teste com parâmetros fixos de ± 1 mT, 15 Hz, com 25 ciclos repetidos por 200 microssegundos. Após a eutanásia as peças foram separadas e preparadas para o teste mecânico, análises histomorfométricas, microtomografia computadorizada (µCT) e ensaios biológicos in vitro. Os dados foram tabulados e a análise de variância ANOVA foi aplicada, com nível de significância de 5%. Os resultados obtidos revelaram que, GTB apresentou melhores resultados em comparação ao GTA nos testes de torque de remoção em 07 dias; no volume ósseo e densidade mineral óssea, ambos em 07, 21 e 45 dias; na proliferação celular em 21 dias, na viabilidade celular em 07 e 45 dias, no conteúdo de proteína total em 07 dias e nódulos de mineralização em 03 e 07 dias. O GTA apresentou melhor desempenho na avaliação da espessura do osso trabecular em 03 dias e na proliferação celular em 03 e 45 dias comparado ao GTB. Os grupos teste apresentaram resultados superiores ao controle nas avaliações de contato osso-implante, espessura do osso trabecular, na viabilidade celular, conteúdo de proteína total e fosfatase alcalina. Na análise histomorfométrica e no número de trabéculas não houve diferenças entre os grupos teste. Com os resultados pode-se concluir que, a aplicação do campo eletromagnético pulsado como um bioestimulador foi efetivo na otimização dos eventos no tecido ósseo que acarretam na osseointegração, especialmente quando aplicado por menor tempo e nos períodos iniciais do reparo ósseo(AU)


The use of biophysical stimulation through the pulsed electromagnetic field modality (PEMF) for the treatment of various conditions in bone tissue has aroused scientific interest for decades. However, the wide variety of parameters and protocols used and the divergence of results in the literature make it difficult to establish a methodology that is effective in the context of therapy with osseointegrated implants. Thus, it is important to evaluate the effect of different application times of the standardized PEMF at different times in the osseointegration process of titanium implants inserted in tibiae of rats. For this, 60 animals (Rattus norvegicus, variation albinus, Wistar) were used, randomized in three experimental groups: control, test A (GTA) submitted for 3 hours of CEMP, and test B (GTB) with 1 hour of PEMF, and the exposure occurred in 5 days weekly during the trial period. All animals received implants in both tibiae, and the application of PEMF only occurred in the test groups with fixed parameters ± 1 mT, 15 Hz, with 25 cycles repeated for 200 microseconds. After euthanasia, the pieces were separated and prepared for mechanical testing, histomorphometric analysis, computed microtomography (µCT) and in vitro biological tests. Data were tabulated and ANOVA analysis of variance was applied, with a significance level of 5%. The results obtained revealed that, GTB presented better results in comparison to GTA in the removal torque tests in 07 days; in bone volume and bone mineral density, both at 07, 21 and 45 days; cell proliferation in 21 days, cell viability in 07 and 45 days, total protein content in 07 days and mineralization nodules in 03 and 07 days. GTA performed better in assessing trabecular bone thickness in 03 days and in cell proliferation in 03 and 45 days compared to GTB. The test groups showed results superior to the control in assessments of boneimplant contact, trabecular bone thickness , in cell viability, total protein content and alkaline phosphatase. In the histomorphometric analysis and in the number of trabeculae, there were no differences between the test groups. With the results it can be concluded that the application of the pulsed electromagnetic field as a biostimulator was effective in the optimization of the events in the bone tissue that result in osseointegration, especially when applied for a shorter time and in the initial periods of bone repair(AU)


Subject(s)
Osseointegration , Electromagnetic Fields , Bone-Anchored Prosthesis/adverse effects
18.
Int. j. morphol ; 37(2): 719-723, June 2019. tab, graf
Article in English | LILACS | ID: biblio-1002283

ABSTRACT

Mobile phone use has increased rapidly. The central nervous system has been shown to be adversely affected by its electromagnetic field (EMF) resulting in headache and sleep disturbances. How the cells make up the CNS and are affected by EMF is unclear. However, because of their central role in inflammation through diverse stimuli including radiation, this study aimed to investigate the effects of electromagnetic fields induced by mobile phones on mast cells in rat dura mater. A total of 18 adult, female, SpragueDawley rats were divided into two groups. The choice of female rats for his study was based on recent surveys demonstrating that mobile phone use is more frequent and prolonged among females. The study group was exposed to 900 MHz electromagnetic field (1 h/day for 45 days). In the end of the study, duramater tissue was extracted and stained using Toluidine blue. Mast cells were counted and results were analysed using Student t test. Mean mast cell number was 202.33±9.82 and 456.78±35.01 in the control and study groups, respectively (p<0.05). Analysis of serum electrolyte and immunoglobulin E levels showed no statistically significant difference between the two groups (p>0.05). The study showed that mobile phone exposure increased mast cell number and degranulation in rat dura mater. Further studies are required to evaluate the clinical implications of these findings.


El uso del teléfono móvil ha aumentado rápidamente. Se ha demostrado que el sistema nervioso central (SNC) se ve afectado de manera adversa debido al campo electromagnético (CEM) que produce dolor de cabeza y trastornos del sueño. No está claro cómo se ve afectada la composición celular del SNC por el CEM. Sin embargo, debido a su función principal en la inflamación a través de diversos estímulos que incluyen la radiación, este estudio tuvo como objetivo investigar los efectos de los campos electromagnéticos inducidos por los teléfonos móviles en los mastocitos de la duramadre de ratas. Un total de 18 ratas Sprague-Dawley adultas, hembras, se dividieron en dos grupos. Se usaron ratas hembras para este estudio en base a investigaciones recientes que han demostrado que el uso de teléfonos móviles es más frecuente y prolongado en las mujeres. Los grupos de estudio fueron expuestos a un campo electromagnético de 900 MHz (1 h / día durante 45 días). Al término del estudio, fue extirpado el tejido de la duramadre y teñido con azul de toluidina. Se contaron los mastocitos y se analizaron los resultados utilizando la prueba t de Student. La cantidad media de células cebadas fue de 202,33 ± 9.82 y 456,78 ± 35,01 en los grupos control y estudio, respectivamente (p <0,05). El análisis del electrolito sérico y los niveles de inmunoglobulina E no mostraron diferencias estadísticamente significativas entre los dos grupos (p> 0,05). El estudio mostró que la exposición a teléfonos móviles aumentó el número de mastocitos y la desgranulación en la duramadre de las ratas. Se requieren estudios adicionales para evaluar las implicaciones clínicas de estos hallazgos.


Subject(s)
Animals , Rats , Cell Phone , Dura Mater/radiation effects , Electromagnetic Fields/adverse effects , Mast Cells/radiation effects , Rats, Sprague-Dawley
19.
Braz. j. otorhinolaryngol. (Impr.) ; 85(3): 282-289, May-June 2019. tab, graf
Article in English | LILACS | ID: biblio-1011624

ABSTRACT

Abstract Introduction: In daily life biological systems are usually exposed to magnetic field forces at different intensities and frequencies, either directly or indirectly. Despite negative results, the therapeutic use of the low dose magnetic field has been found in recent studies. The effect of magnetic field forces on cochlear cells is not clear in the literature. Objective: In our study, we first applied in vivo pulsed magnetic fields to laboratory rats to investigate the effects on cochlea with distortion product otoacoustic emission test followed by histopathological examinations. Methods: Twelve rats were included in this study, separated into two groups as study group and control group. The rats in the study group were exposed to 40 Hz pulsed magnetic field for 1 h/day for 30 days; the hearing of the rats was controlled by otoacoustic emission test. Also, their cochleas were removed and histochemical examination was performed by Caspase-3, Caspase-9, and TUNEL methods. Results: A statistically significant difference was determined (p < 0.05) when the hearing thresholds of the groups obtained by using 5714 Hz and 8000 Hz stimuli were compared by Kruskal-Wallis test. A significant reaction was observed in the study group, especially in the outer ciliated cells during immunohistochemical examinations by using Caspase-3 and Caspase-9 methods. A significantly positive difference was determined in the study group, especially at the outer ciliated cells and the support cells of the corti organ, when compared to the control group (p < 0.05) by the TUNEL method. Conclusion: According to the results of our study, the very low dose magnetic field, which is considered to be used for therapeutic purposes recently, can cause both auditory function defects and histopathologic damage in cochlear cells.


Resumo Introdução: Os sistemas biológicos são geralmente expostos a forças de campo magnético em diferentes intensidades e frequências, direta ou indiretamente, na vida diária. Apesar dos resultados negativos, o uso terapêutico do campo magnético de baixa dose tem sido encontrado em estudos recentes. O efeito das forças do campo magnético sobre as células cocleares não está claro na literatura. Objetivo: Em nosso estudo, aplicamos pela primeira vez campos magnéticos pulsados in vivo em ratos de laboratório para investigar os efeitos na cóclea através do teste de emissão otoacústica por produto de distorção e análises histopatológicas. Método: Doze ratos foram incluídos neste estudo, os quais foram separados em dois grupos, grupo de estudo e grupo controle. Os ratos do grupo de estudo foram expostos a campo magnético pulsado de 40 Hz por 1 hora/dia por 30 dias, e a audição dos ratos foi controlada por testes de emissão otoacústica. Além disso, suas cócleas foram colhidas e o exame histoquímico foi feito pelos métodos caspase-3, caspase-9 e TUNEL. Resultados: Foi determinada uma diferença estatisticamente significante (p < 0,05) quando os limiares auditivos dos grupos obtidos por meio dos estímulos de 5714 Hz e 8000 Hz foram comparados pelo teste de Kruskal-Wallis. Uma reação significante foi observada no grupo de estudo, especialmente nas células ciliadas externas nas análises imuno-histoquímicas, com os métodos caspase-3 e caspase-9. Uma diferença significantemente positiva foi determinada no grupo de estudo, especialmente nas células ciliadas externas e nas células de suporte do órgão de Corti, quando comparadas com o grupo controle (p < 0,05) pelo método TUNEL. Conclusão: De acordo com os resultados do nosso estudo, o campo magnético de dose baixa, que tem sido considerado para uso terapêutico recentemente, pode causar defeitos na função auditiva e danos histopatológicos nas células cocleares.


Subject(s)
Animals , Male , Rats , Cochlea/pathology , Hair Cells, Auditory, Outer/pathology , Electromagnetic Fields/adverse effects , Immunohistochemistry , Rats, Wistar , Otoacoustic Emissions, Spontaneous , Statistics, Nonparametric
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