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Variations in occupational exposure to magnetic fields among welders in Malaysia

Man AK, Shahidan R

Radiat Prot Dosimetry, 2008;128(4):444-8.
PMID: 18045796

This study attempted to estimate the lifelong magnetic field (MF) exposures of a particular group of welders. Exposure was quantified via measurements, observations and interviews. It was found that these welders face a vast range of lifelong MF exposures depending on the welding processes and duration of the welding tasks performed. This may explain the inconsistency in the results of studies of MF exposures on human health. The mere assessing of the MF exposure levels through spot measurements does not give an overall picture of the total amount of exposure received by the welders as some of these workers performed the welding task throughout the day, whereas others performed this as a part of their job. The exposure to various chemicals in the fume may complicate the interpretation of the elevated health risk among the welders.

Matched MeSH terms: Electromagnetic Fields*
Transient electro-magneto-hydrodynamic two-phase blood flow and thermal transport through a capillary vessel

Mirza IA, Abdulhameed M, Vieru D, Shafie S

Comput Methods Programs Biomed, 2016 Dec;137:149-166.
PMID: 28110721 DOI: 10.1016/j.cmpb.2016.09.014

Therapies with magnetic/electromagnetic field are employed to relieve pains or, to accelerate flow of blood-particles, particularly during the surgery. In this paper, a theoretical study of the blood flow along with particles suspension through capillary was made by the electro-magneto-hydrodynamic approach. Analytical solutions to the non-dimensional blood velocity and non-dimensional particles velocity are obtained by means of the Laplace transform with respect to the time variable and the finite Hankel transform with respect to the radial coordinate. The study of thermally transfer characteristics is based on the energy equation for two-phase thermal transport of blood and particles suspension with viscous dissipation, the volumetric heat generation due to Joule heating effect and electromagnetic couple effect. The solution of the nonlinear heat transfer problem is derived by using the velocity field and the integral transform method. The influence of dimensionless system parameters like the electrokinetic width, the Hartman number, Prandtl number, the coefficient of heat generation due to Joule heating and Eckert number on the velocity and temperature fields was studied using the Mathcad software. Results are presented by graphical illustrations.

Matched MeSH terms: Electromagnetic Fields*
Fulltext Dielectric properties for selected wall material in the development of microwave-encapsulation-drying

Mohamad SNH, Muhamad II, Mohd Jusoh YM, Khairuddin N

J Food Sci Technol, 2018 Dec;55(12):5161-5165.
PMID: 30483013 DOI: 10.1007/s13197-018-3327-3

Dielectric properties study is important in understanding the interaction between materials within electromagnetic field. By knowing and understanding the dielectric properties of materials, an efficient and effective microwave heating process and products can be designed. In this study, the dielectric properties of several encapsulation wall materials were measured using open-ended coaxial probe method. This method was selected due to its simplicity and high accuracy. All materials exhibited similar behavior. The result inferred that β-cyclodextrin (BC), starch (S), Arabic (GA) and maltodextrin (M) with various dextrose equivalent exhibited effective encapsulation wall materials in microwave encapsulation-drying technique owing to loss tangent values which were higher than 0.1 at general application frequency of 2.45 GHz. Thus, these were found to be suitable as wall material to encapsulate the selected core material in this microwave encapsulation-drying method. On contrary, sodium caseinate showed an ineffective wall material to be used in microwave encapsulation-drying. The differences in the values of dielectric constant, loss factor and loss tangent were found to be contributed by frequency, composition and bulk density.

Matched MeSH terms: Electromagnetic Fields
Prospects of plasma immersion ion implantation and deposition (PIlI & D) in the biomaterials field in Malaysia and south East Asia

Mohamed MH

Med J Malaysia, 2004 May;59 Suppl B:19-20.
PMID: 15468798

One of the emerging technologies in the area of plasma processing is plasma immersion ion implantation (PSII). The paper addresses the merits offered by the PSII technique especially in the area of biomaterial processing. Worldwide development status as well as the drive towards commercial applications is elaborated in an attempt to draw the attention to the importance of the process for Malaysia as well as south East Asia.

Matched MeSH terms: Electromagnetic Fields*
Fulltext Effect of radio-frequency electromagnetic radiations (RF-EMR) on passive avoidance behaviour and hippocampal morphology in Wistar rats

Narayanan SN, Kumar RS, Potu BK, Nayak S, Bhat PG, Mailankot M

Ups. J. Med. Sci., 2010 May;115(2):91-6.
PMID: 20095879 DOI: 10.3109/03009730903552661

The interaction of mobile phone radio-frequency electromagnetic radiation (RF-EMR) with the brain is a serious concern of our society.

Matched MeSH terms: Electromagnetic Fields*
Radiofrequency electromagnetic radiation-induced behavioral changes and their possible basis

Narayanan SN, Jetti R, Kesari KK, Kumar RS, Nayak SB, Bhat PG

Environ Sci Pollut Res Int, 2019 Oct;26(30):30693-30710.
PMID: 31463749 DOI: 10.1007/s11356-019-06278-5

The primary objective of mobile phone technology is to achieve communication with any person at any place and time. In the modern era, it is impossible to ignore the usefulness of mobile phone technology in cases of emergency as many lives have been saved. However, the biological effects they may have on humans and other animals have been largely ignored and not been evaluated comprehensively. One of the reasons for this is the speedy uncontrollable growth of this technology which has surpassed our researching ability. Initiated with the first generation, the mobile telephony currently reaches to its fifth generation without being screened extensively for any biological effects that they may have on humans or on other animals. Mounting evidences suggest possible non-thermal biological effects of radiofrequency electromagnetic radiation (RF-EMR) on brain and behavior. Behavioral studies have particularly concentrated on the effects of RF-EMR on learning, memory, anxiety, and locomotion. The literature analysis on behavioral effects of RF-EMR demonstrates complex picture with conflicting observations. Nonetheless, numerous reports suggest a possible behavioral effect of RF-EMR. The scientific findings about this issue are presented in the current review. The possible neural and molecular mechanisms for the behavioral effects have been proposed in the light of available evidences from the literature.

Matched MeSH terms: Electromagnetic Fields/adverse effects*
Fulltext Enhancement of mesenchymal stem cell chondrogenesis with short-term low intensity pulsed electromagnetic fields

Parate D, Franco-Obregón A, Fröhlich J, Beyer C, Abbas AA, Kamarul T, et al.

Sci Rep, 2017 08 25;7(1):9421.
PMID: 28842627 DOI: 10.1038/s41598-017-09892-w

Pulse electromagnetic fields (PEMFs) have been shown to recruit calcium-signaling cascades common to chondrogenesis. Here we document the effects of specified PEMF parameters over mesenchymal stem cells (MSC) chondrogenic differentiation. MSCs undergoing chondrogenesis are preferentially responsive to an electromagnetic efficacy window defined by field amplitude, duration and frequency of exposure. Contrary to conventional practice of administering prolonged and repetitive exposures to PEMFs, optimal chondrogenic outcome is achieved in response to brief (10 minutes), low intensity (2 mT) exposure to 6 ms bursts of magnetic pulses, at 15 Hz, administered only once at the onset of chondrogenic induction. By contrast, repeated exposures diminished chondrogenic outcome and could be attributed to calcium entry after the initial induction. Transient receptor potential (TRP) channels appear to mediate these aspects of PEMF stimulation, serving as a conduit for extracellular calcium. Preventing calcium entry during the repeated PEMF exposure with the co-administration of EGTA or TRP channel antagonists precluded the inhibition of differentiation. This study highlights the intricacies of calcium homeostasis during early chondrogenesis and the constraints that are placed on PEMF-based therapeutic strategies aimed at promoting MSC chondrogenesis. The demonstrated efficacy of our optimized PEMF regimens has clear clinical implications for future regenerative strategies for cartilage.

Matched MeSH terms: Electromagnetic Fields*
Molecular orbitals of delocalized electron clouds in neuronal domains

Poznanski RR, Cacha LA, Latif AZA, Salleh SH, Ali J, Yupapin P, et al.

Biosystems, 2019 Sep;183:103982.
PMID: 31195028 DOI: 10.1016/j.biosystems.2019.103982

We have further developed the two-brains hypothesis as a form of complementarity (or complementary relationship) of endogenously induced weak magnetic fields in the electromagnetic brain. The locally induced magnetic field between electron magnetic dipole moments of delocalized electron clouds in neuronal domains is complementary to the exogenous electromagnetic waves created by the oscillating molecular dipoles in the electro-ionic brain. In this paper, we mathematically model the operation of the electromagnetic grid, especially in regard to the functional role of atomic orbitals of dipole-bound delocalized electrons. A quantum molecular dynamic approach under quantum equilibrium conditions is taken to illustrate phase differences between quasi-free electrons tethered to an oscillating molecular core. We use a simplified version of the many-body problem to analytically solve the macro-quantum wave equation (equivalent to the Kohn-Sham equation). The resultant solution for the mechanical angular momentum can be used to approximate the molecular orbital of the dipole-bound delocalized electrons. In addition to non-adiabatic motion of the molecular core, 'guidance waves' may contribute to the delocalized macro-quantum wave functions in generating nonlocal phase correlations. The intrinsic magnetic properties of the origins of the endogenous electromagnetic field are considered to be a nested hierarchy of electromagnetic fields that may also include electromagnetic patterns in three-dimensional space. The coupling between the two-brains may involve an 'anticipatory affect' based on the conceptualization of anticipation as potentiality, arising either from the macro-quantum potential energy or from the electrostatic effects of residual charges in the quantum and classical subsystems of the two-brains that occurs through partitioning of the potential energy of the combined quantum molecular dynamic system.

Matched MeSH terms: Electromagnetic Fields
Evaluation of Interference of Cellular Phones on Electronic Apex Locators: An In Vitro Study

Sidhu P, Shankargouda S, Dicksit DD, Mahdey HM, Muzaffar D, Arora S

J Endod, 2016 Apr;42(4):622-5.
PMID: 26850688 DOI: 10.1016/j.joen.2015.12.027

INTRODUCTION: Use of mobile phone has been prohibited in many hospitals to prevent interference with medical devices. Electromagnetic radiation emitted from cellular phones might interfere with electronic working length determination. The purpose of this in vitro study was to evaluate the effect of a smart phone (Samsung Galaxy Note Edge) on working length determination of electronic apex locators (EALs) Propex II and Rootor.
METHODS: Fifteen intact, non-carious single-rooted teeth were decoronated at the cementoenamel junction. Visually, working length was determined by using a #15 K-file under stereomicroscope (×20). The effect of cellular phones on electronic working length (EWL) was determined under 2 experimental settings: (1) in a closed room with poor signal strength and (2) in a polyclinic set up with good signal strength and 5 conditions: (1) electronically, without cellular phone in room; (2) electronically, with cellular phone in physical contact with EAL; (3) electronically, with mobile phone in physical contact with EAL and in calling mode for a period of 25 seconds; (4) electronically, mobile phone placed at a distance of 40 cm from the EAL; and (5) electronically, mobile phone placed at a distance of 40 cm and in calling mode for a period of 25 seconds. The EWL was measured 3 times per tooth under each condition. Stability of the readings was scored from 1 to 3: (1) good stability, (2) stable reading after 1 attempt, and (3) stable reading after 2 attempts. The data were compared by using analysis of variance.
RESULTS: The EWL measurements were not influenced by the presence of cellular phone and could be determined under all experimental conditions.
CONCLUSIONS: Within the limitations of this study, it can be concluded that mobile phones do not interfere with the EWL determination.

Matched MeSH terms: Electromagnetic Fields
Fulltext Combination effect of argan oil and low frequency electromagnetic field on open wound in mice

Siti F. Masre, Muzamir, M.K, Sabarina, I., Jehan, N., Yanti Rosli

Jurnal Sains Kesihatan Malaysia, 2018;16(101):41-45.
MyJurnal

This study was conducted to evaluate the effect of argan oil with the exposure of low frequency electromagnetic field (EMF) on open wound healing in mice. Eighteen male mice (20-40 g) were divided into three groups: phosphate buffer saline (PBS) as negative control, solcoseryl gel as positive control, and argan oil with the exposure of low frequency EMF, 1.2 mT (treatment group). Full thickness wounds (4 mm diameter) were induced on the shaved dorsal of the mouse. All mice were sacrificed on day 12 after the final treatment. Macroscopic observation, wound contraction rate, histopathology analysis and total protein content were examined in this study. Results showed that wounds treated with argan oil and exposed to low frequency EMF has a significant increase in wound contraction rate (p < 0.05) and total protein content (p < 0.05). Moreover, histopathological analysis on the wound tissues displayed complete re-epithelization with thick and dense collagen fibers in the argan oil with low frequency EMF exposure treated group. In conclusion, topical treatment of argan oil with low frequency EMF exposure yield a better healing progress and showed the ability to accelerate wound healing

Matched MeSH terms: Electromagnetic Fields
Fulltext Measurement and Mapping of Wi-Fi Radiation Level at Hamdan Tahir Library, Universiti Sains Malaysia Health Campus

Supardi, N. F., Mohd Taib, N. H., Abu Amat, N. H., Yusoff, M. N. S.

Physics and Technology in Medicine, 2020;1(1):52-57.
MyJurnal

Wi-Fi is a wireless communication technology that uses specific electromagnetic frequencies. The increasing use of Wi-Fi has raised public concerns about the impact of electromagnetic radiation on the environment and human health. Since the exposure level of the electromagnetic field (EMF) radiation differs between different locations, it is important to measure the strength of the EMF at various locations under observation. This study aimed to obtain specific values related to the radiofrequency and microwave EMF which is described by four specific parameters, that are 1) the frequency of the wave, 2) the electric field strength E, 3) the magnetic field strength H, and 4) the power density S. This study was carried out at the first floor area of Hamdan Tahir Library, Universiti Sains Malaysia Health Campus. Mapping of Wi-Fi signal and measurement of Wi-Fi radiation level was performed at four specific locations, that are Laptop zone 1, Laptop zone 2, Computer lab, and Cozy corner. The average radiation level was compared with the ICNIRP standard limit for public user. It was observed that the Wi-Fi signal was highest in Laptop zone 2 followed by Laptop zone 1 which displayed a moderate signal strength. Whereas moderate but lower signal level was detected in Computer lab zone and Cozy corner. The electric and magnetic fields as well as power density were found highest in Laptop zone 1, followed by Laptop zone 2, Cozy corner, and Computer lab. Comparison with standard ICNIRP limit showed that the radiation level is still far below the ICNIRP limit, which is only 2% of exposure level. To conclude, Laptop zone 2 exhibited the strongest Wi-Fi signal whereas Laptop zone 1 displayed the highest radiation level. However, the strength of the electric and magnetic fields as well as power density is still far below the ICNIRP limit.

Matched MeSH terms: Electromagnetic Fields
Fulltext Harnessing energy from electromagnetic field: practical implementation integrating coil antenna and IC load

Syahrizal Salleh, Zulkifli Abd Majid

Pertanika Journal of Science & Technology, 2013;21(2):555-566.
MyJurnal

An AC to DC voltage rectifier and its respective regulator were designed and integrated on a 0.25μm CMOS process. Its input impedance was measured along with the regulated DC output. Input impedance of a series of rectangular coil microstrip antenna on FR4 PCB with outer dimension of 78mm x 41mm was measured. The positive reactance of the antenna was matched at resonance with negative reactance of the integrated rectifier and regulator with addition of external capacitor. Relationship between incidental electromagnetic field in A/m at the coil microstrip antenna all the way to the rectified DC voltage at the output of the regulator is presented. In the context of wireless power transfer, this work focuses on the remote unit that absorbs electromagnetic field generated by another system and converts the energy into DC supply voltage for remote device

Matched MeSH terms: Electromagnetic Fields
Fulltext Effects of electromagnetic field (EMF) on histological changes and norepinephrine levels in the brains of adult male rats

Yap, Hui Cin, Asmah Hamid, Farah Wahida Ibrahim, Nor Fadilah Rajab, Yanti Rosli

Jurnal Sains Kesihatan Malaysia, 2016;14(1):55-61.
MyJurnal

The emergence of research about the biological effects of electromagnetic field (EMF) have growing concern among
researchers. The aim of this study was to investigate the effects on the brain of rats periodically exposed to 0.1 mT EMF.
Total 24 adult male Sprague Dawley rats were subdivided randomly to 4 groups: 2 control groups (C1 6 hours: 6 h/
day for 5 days; C2 20 hours: 20 h/day for 5 days) and 2 treatment groups which exposed to 0.1 mT EMF (T1 6 hours:
6 h/day for 5 days; T2 20 hours: 20 h/day for 5 days). A significant decrease in the pyramidal cell number was higher
as the exposure duration to EMF was extended (T1, p

Matched MeSH terms: Electromagnetic Fields

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