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https://read.qxmd.com/read/30874826/-mri-interactions-with-magnetically-active-and-electrically-conductive-material
#1
REVIEW
F Schick
BACKGROUND: Patients undergoing MRI examinations are exposed to a strong static magnetic field and powerful electromagnetic alternating fields. Undesired or even dangerous effects could be caused if implants or objects with magnetic or electrically conductive elements are accidentally brought into the examination area. METHODS: Relevant interactions in MRI between magnetic/electric fields and body tissue as well as foreign materials are systematically presented, based on proven physical principles...
March 14, 2019: Der Radiologe
https://read.qxmd.com/read/30857115/assessment-of-radiofrequency-electromagnetic-field-exposure-from-personal-measurements-considering-the-body-shadowing-effect-in-korean-children-and-parents
#2
Jonghyuk Choi, Jung-Hwan Hwang, Hyungrul Lim, Hyunjoo Joo, Hee-Sun Yang, Yong-Han Lee, Marloes Eeftens, Benjamin Struchen, Martin Röösli, Ae-Kyoung Lee, Hyung-Do Choi, Jong Hwa Kwon, Mina Ha
We aimed to assess the personal radiofrequency electromagnetic field (RF-EMF) exposure levels of children and adults through their activities, with consideration to the body shadowing effect. We recruited 50 child-adult pairs, living in Seoul, Cheonan, and Ulsan, South Korea. RF-EMF measurements were performed between September and December 2016, using a portable exposure meter tailored to capture 14 Korean radiofrequency (RF) bands ranging from 87.5 to 5875MHz. The participants carried the device for 48h and kept a time-activity diary using a smartphone application in flight mode...
June 15, 2018: Science of the Total Environment
https://read.qxmd.com/read/30803001/a-numerical-and-experimental-study-of-rf-shimming-in-the-presence-of-hip-prostheses-using-adaptive-sar-at-3-t
#3
Aurelien Destruel, Miguel Fuentes, Ewald Weber, Kieran O'Brien, Jin Jin, Feng Liu, Markus Barth, Stuart Crozier
PURPOSE: Parallel transmission techniques in MRI have the potential to improve the image quality near metal implants at 3 T. However, current testing of implants only evaluates the risk of radiofrequency (RF) heating in phantoms in circularly polarized mode. We investigate the influence of changing the transmission settings in a 2-channel body coil on the peak temperature near 2 CoCrMo hip prostheses, using adaptive specific absorption rate (SAR) as an estimate of RF heating. METHODS: Adaptive SAR is a SAR averaging method that is optimized to correlate with thermal simulations and limit the temperature to 39°C near hip implants...
February 25, 2019: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://read.qxmd.com/read/30773725/wireless-coils-based-on-resonant-and-nonresonant-coupled-wire-structure-for-small-animal-multinuclear-imaging
#4
Tania S Vergara Gomez, Marc Dubois, Stanislav Glybovski, Benoit Larrat, Julien de Rosny, Carsten Rockstuhl, Monique Bernard, Redha Abdeddaim, Stefan Enoch, Frank Kober
Earlier work on RF metasurfaces for preclinical MRI has targeted applications such as whole-body imaging and dual-frequency coils. In these studies, a nonresonant loop was used to induce currents into a metasurface that was operated as a passive inductively powered resonator. However, as we show in this study, the strategy of using a resonant metasurface reduces the impact of the loop on the global performance of the assembled coil. To mitigate this deficiency, we developed a new approach that relies on the combination of a commercial surface coil and a coupled-wire structure operated away from its resonance...
February 17, 2019: NMR in Biomedicine
https://read.qxmd.com/read/30755096/modulation-of-antioxidant-enzyme-gene-expression-by-extremely-low-frequency-electromagnetic-field-in-post-stroke-patients
#5
Natalia Cichon, Michal Bijak, Ewelina Synowiec, Elzbieta Miller, Tomasz Sliwinski, Joanna Saluk-Bijak
Oxidative stress plays the most important role in the pathogenesis of stroke. Extremely low frequency electromagnetic field (ELF-EMF) therapy may be complementary in post-stroke therapy, as it modulates oxidative stress. The aim of this study was to evaluate the messenger ribonucleic acid (mRNA) levels of certain antioxidant genes in post-stroke patients given ELF-EMF therapy. Forty-eight post-stroke patients were divided into two groups: an ELF-EMF group and a non-ELF-EMF group. All patients underwent the same program of physical therapy, but the ELF-EMF group was additionally given ELF-EMF treatment...
November 2018: Scandinavian Journal of Clinical and Laboratory Investigation
https://read.qxmd.com/read/30732836/fully-immersed-state-absorption-and-electrophysiological-effects-of-the-ovo-whole-body-perceptual-deprivation-chamber
#6
Tal Dotan Ben-Soussan, Federica Mauro, Stefano Lasaponara, Joseph Glicksohn, Fabio Marson, Aviva Berkovich-Ohana
Absorption, the ability to highly focus attention, as well as openness to self-altering experiences, is an important psychological construct, closely related to deep-meditation states and other altered states of consciousness. Yet, little is known about the electrophysiological profile of states of absorption, possibly due to the difficulty to induce this state in the lab. While most studies have used a visual Ganzfeld (homogeneous perceptual field), here we use a novel technique of full immersion-the OVO Whole-Body Perceptual Deprivation (OVO-WBPD) chamber, which is an altered sensory environment in the form of a human-sized egg...
2019: Progress in Brain Research
https://read.qxmd.com/read/30724881/-intracellular-regeneration-of-adrenocorticocytes-in-response-to-the-prophylactic-application-of-low-intensity-electromagnetic-radiation-under-the-conditions-of-radiation-an-experimental-study
#7
Yu N Korolev, M S Geniatulina, L V Mikhailik, L A Nikulina
BACKGROUND: Adaptation of the organism to the action of certain damaging factors, including radiation, is closely related to the state of the hypothalamic-pituitary-adrenal system. The important role in its activities is played by adrenocorticocytes (ACC) - the cells of the fascicular zone of the adrenal cortex. The disturbance of the structure and function of these cells can significantly impair and limit the development of the adaptive reactions in the body. One of the most promising ways to prevent the post-radiation changes in adrenocorticocytes consists of the application of the non-pharmacological therapeutic factors, such as low-intensity electromagnetic radiation (EMR) of ultra high frequency ( UHF) and the low-frequency (LF) magnetic field (MF) of low intensity (LI) after the exposition of the cells to the action of radiation...
2019: Voprosy Kurortologii, Fizioterapii, i Lechebnoĭ Fizicheskoĭ Kultury
https://read.qxmd.com/read/30674958/early-exposure-to-radiofrequency-electromagnetic-fields-at-1850-mhz-affects-auditory-circuits-in-early-postnatal-mice
#8
Ju Hwan Kim, Yang Hoon Huh, Jae-Hun Lee, Jae Yun Jung, Seung Cheol Ahn, Hak Rim Kim
In the present study, we measured the spontaneous post synaptic currents (sPSCs) at the post synaptic principle cells of the medial nucleus of the trapezoid body (MNTB) in early postnatal mice after exposure to 1850 MHz radiofrequency electromagnetic fields (RF-EMF). sPSC frequencies and amplitudes were significantly increased in the RF-EMF exposed group. Moreover, the number of synaptic vesicles in the calyx of Held was significantly increased in presynaptic nerve terminals. Following RF-EMF exposure, the number of docking synaptic vesicles in the active zone increased, thereby expanding the total length of the presynaptic active zone in the calyx of Held...
January 23, 2019: Scientific Reports
https://read.qxmd.com/read/30644277/biophysical-stimulation-of-the-knee-with-pemfs-from-bench-to-bedside
#9
G Vicenti, D Bizzoca, V S Nappi, F Moretti, M Carrozzo, V Belviso, B Moretti
Clinical biophysics investigates the relationship between non-ionizing physical energy and the human body. Although several types of electrical stimulation devices have received US FDA approval for orthopaedic application, the use of Pulsed Electromagnetic Field (PEMFs) play a central role in joint biophysics. This narrative review aims to summarize the current evidences on the efficacy of PEMF-therapy in the treatment of knee articular diseases. Preclinical studies have assessed the effects of PEMFs on chondrocytes, synoviocytes, articular cartilage explants and animal models, showing positive effects of PEMF-therapy on cells proliferation, extracellular matrix (ECM) production, chondrocytes apoptosis and inflammatory cytokines down-regulation...
November 2018: Journal of Biological Regulators and Homeostatic Agents
https://read.qxmd.com/read/30627371/exposure-to-cell-phone-radiofrequency-changes-corticotrophin-hormone-levels-and-histology-of-the-brain-and-adrenal-glands-in-male-wistar-rat
#10
Sima Shahabi, Iman Hassanzadeh Taji, Maedeh Hoseinnezhaddarzi, Fateme Mousavi, Shermineh Shirchi, Atena Nazari, Hooman Zarei, Fereshteh Pourabdolhossein
Objectives: Nowadays, the electromagnetic field-emitting devices are used routinely in our lives. Controversial reports exist concerning the effects of mobile radiofrequency (RF) on different parts of the body, especially stress hormones. The main goal of the present work was to study the long-term effects of mobile RF900 MHz exposure with special focus on the adrenal gland pathophysiology and function. Materials and Methods: Adult male Wistar rats were exposed to mobile RF 6 hr daily for 4-8 weeks...
December 2018: Iranian Journal of Basic Medical Sciences
https://read.qxmd.com/read/30625451/the-quot-virtual-dbs-population-quot-five-realistic-computational-models-of-deep-brain-stimulation-patients-for-electromagnetic-mr-safety-studies
#11
Bastien Guerin, Maria Ida Iacono, Mathias Davids, Darin D Dougherty, Leonardo M Angelone, Lawrence L Wald
We design, develop, and disseminate a "virtual population" of five realistic computational models of deep brain stimulation (DBS) patients for electromagnetic (EM) analysis. We found five DBS patients in our institution' research patient database who received high quality post-DBS surgery computer tomography (CT) examinations of the head and neck. Three patients have a single implanted pulse generator (IPG) and the two others have two IPGs (one for each lead). Moreover, one patient has two abandoned leads on each side of the head...
January 9, 2019: Physics in Medicine and Biology
https://read.qxmd.com/read/30598286/harnessing-electroceuticals-to-treat-disorders-arising-from-traumatic-stress-theoretical-considerations-using-a-psychosensory-model
#12
Ronald A Ruden
Traumatically encoded memories can last a lifetime. These memories, either by purposeful or inadvertent re-activation, cause the release of stress hormones and generate a persistent and inescapable allostatic load on the body, brain and mind. This leads to a maladaptive response, as the ability to return to pre-event homeostasis is no longer possible. The consequence of this response is that it increases risk for further traumatization and other disorders. Remarkably, recent research has shown that these memories become labile and subject to disruption upon recall...
September 6, 2018: Explore: the Journal of Science and Healing
https://read.qxmd.com/read/30580045/high-permittivity-ceramics-improve-the-transmit-field-and-receive-efficiency-of-a-commercial-extremity-coil-at-1-5-tesla
#13
Irena Zivkovic, Wouter Teeuwisse, Alexey Slobozhanyuk, Elizaveta Nenasheva, Andrew Webb
OBJECTIVE: The purpose of this work is to investigate the use of ceramic materials (based on BaTiO3 with ZrO2 and CeO2 -additives) with very high relative permittivity (εr  ∼ 4500) to increase the local transmit field and signal-to-noise ratio (SNR) for commercial extremity coils on a clinical 1.5 T MRI system. METHODS: Electromagnetic simulations of transmit efficiency and specific absorption rate (SAR) were performed using four ferroelectric ceramic blocks placed around a cylindrical phantom, as well as placing these ceramics around the wrist of a human body model...
December 15, 2018: Journal of Magnetic Resonance
https://read.qxmd.com/read/30561338/importance-of-exposure-duration-and-metrics-on-correlation-between-rf-energy-absorption-and-temperature-increase-in-a-human-model
#14
Marta Cavagnaro, James Lin
OBJECTIVE: This study investigated the influence of absorption metrics and averaging schemes on correlation between RF/microwave energy and induced temperature elevation for plane wave exposures. METHODS: A voxel-based, anatomically realistic model of the human body was considered. Correlation of electromagnetic fields and temperature increases were evaluated at several frequencies. Both Specific Absorption Rate (SAR) and Volume Absorption Rate (VAR) were considered...
December 12, 2018: IEEE Transactions on Bio-medical Engineering
https://read.qxmd.com/read/30555917/discovering-the-forbidden-raman-modes-at-the-edges-of-layered-materials
#15
Yao Guo, Weixuan Zhang, Hanchun Wu, Junfeng Han, Yongliang Zhang, Shenghuang Lin, Chunru Liu, Kang Xu, Jingsi Qiao, Wei Ji, Qing Chen, Song Gao, Wenjing Zhang, Xiangdong Zhang, Yang Chai
The edges of layered materials have unique properties that substantially differ from the body regions. In this work, we perform a systematic Raman study of the edges of various layered materials (MoS2 , WS2 , WSe2 , PtS2 , and black phosphorus). The Raman spectra of the edges feature newly observed forbidden Raman modes, which are originally undetectable from the body region. By selecting the edge type and the polarization directions of the incident and scattered light, all forbidden Raman modes are distinctly detected...
December 2018: Science Advances
https://read.qxmd.com/read/30533171/role-of-mitochondria-in-the-oxidative-stress-induced-by-electromagnetic-fields-focus-on-reproductive-systems
#16
REVIEW
Silvano Junior Santini, Valeria Cordone, Stefano Falone, Mahmut Mijit, Carla Tatone, Fernanda Amicarelli, Giovanna Di Emidio
Modern technologies relying on wireless communication systems have brought increasing levels of electromagnetic field (EMF) exposure. This increased research interest in the effects of these radiations on human health. There is compelling evidence that EMFs affect cell physiology by altering redox-related processes. Considering the importance of redox milieu in the biological competence of oocyte and sperm, we reviewed the existing literature regarding the effects of EMFs on reproductive systems. Given the role of mitochondria as the main source of reactive oxygen species (ROS), we focused on the hypothesis of a mitochondrial basis of EMF-induced reproductive toxicity...
2018: Oxidative Medicine and Cellular Longevity
https://read.qxmd.com/read/30530090/exposure-and-health-risks-perception-of-extremely-low-frequency-and-radiofrequency-electromagnetic-fields-and-the-effect-of-providing-information
#17
Mara Gallastegi, Ana Jiménez-Zabala, Amaia Molinuevo, Juan J Aurrekoetxea, Loreto Santa-Marina, Laura Vozmediano, Jesús Ibarluzea
Given that regardless of actual exposure levels, high-risk perceptions of electromagnetic fields of non-ionizing radiation (EMF-NIR) may cause health effects, it is important to understand the mechanisms behind perceptions in the general population. The aims of this study were to assess perceptions of both exposure and health-risk among mothers of the INMA (Environment and childhood)-Gipuzkoa child cohort; to explore possible determinants that explain such perceptions; and to evaluate whether providing information on exposure levels has any effect on perceptions...
November 28, 2018: Environmental Research
https://read.qxmd.com/read/30530085/health-effects-of-wind-turbines-on-humans-in-residential-settings-results-of-a-scoping-review
#18
REVIEW
Alice Freiberg, Christiane Schefter, Maria Girbig, Vanise C Murta, Andreas Seidler
INTRODUCTION: As the global number of wind turbines has increased steadily in recent years, as has the number of studies about putative health effects in residential settings, it is the review purpose to give an overview of the characteristics and methodologies of the scientific literature around the topic in order to identify research gaps and to derive implications for research and practice. Additionally, study findings from higher-quality observational studies as well as results that seem to be of interest for the scientific and political debate are presented...
November 25, 2018: Environmental Research
https://read.qxmd.com/read/30523884/sensitivity-analysis-of-neurodynamic-and-electromagnetic-simulation-parameters-for-robust-prediction-of-peripheral-nerve-stimulation
#19
Valerie Klein, Mathias Davids, Lawrence L Wald, Lothar R Schad, Bastien Guérin
Peripheral nerve stimulation (PNS) has become an important limitation for fast MR imaging using the latest gradient hardware. We have recently developed a simulation framework to predict PNS thresholds and stimulation locations in the body for arbitrary coil geometries to inform the gradient coil optimization process. Our approach couples electromagnetic field simulations in realistic body models to a neurodynamic model of peripheral nerve fibers. In this work, we systematically analyze the impact of key parameters on the predicted PNS thresholds to assess the robustness of the simulation results...
December 19, 2018: Physics in Medicine and Biology
https://read.qxmd.com/read/30481957/possible-effects-of-radiofrequency-electromagnetic-field-exposure-on-central-nerve-system
#20
REVIEW
Ju Hwan Kim, Jin-Koo Lee, Hyung-Gun Kim, Kyu-Bong Kim, Hak Rim Kim
Technological advances of mankind, through the development of electrical and communication technologies, have resulted in the exposure to artificial electromagnetic fields (EMF). Technological growth is expected to continue; as such, the amount of EMF exposure will continue to increase steadily. In particular, the use-time of smart phones, that have become a necessity for modern people, is steadily increasing. Social concerns and interest in the impact on the cranial nervous system are increased when considering the area where the mobile phone is used...
November 27, 2018: Biomolecules & Therapeutics
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