Displaying publications 1 - 20 of 33 in total

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  1. Fulltext Measurement and Mapping of Wi-Fi Radiation Level at Students Hostel in Universiti Sains Malaysia Health Campus
    Abu Amat, N. H., Mohd Taib, N. H., Supardi, N. F., Yusoff, M. N. S.
    Physics and Technology in Medicine, 2020;1(1):38-44.
    MyJurnal
    The increasing use of wireless communication devices, particularly Wi-Fi has raised public concerns on the exposure to electromagnetic field (EMF) and its possible effect on human health. As the exposure level of the EMF radiation varies between different locations, measurement of the EMF strength at various locations is vital. In this study, we aimed to measure the EMF exposure which is described by four specific parameters, specifically 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 performed at the second floor in Nurani hostel block in Desasiswa Murni Nurani, 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 in a student room, television room, prayer room, and ironing room. The average radiation level was compared with the standard limit set by International Commission on Non-Ionizing Radiation Protection (ICNIRP). It was observed that the strength of Wi-Fi signal was highest in students’ room followed by television room. Both of these rooms exhibited high signal strength. While moderate but lower signal level was observed in prayer room followed by ironing room. The electromagnetic field and power density were found highest in students’ room, followed by television room, prayer room, and ironing room. Comparison with standard ICNIRP limit showed that the radiation level is still far below the acceptable limit, which is only 2% of the exposure level. To conclude, students’ room exhibited the strongest Wi-Fi signal and the highest radiation level. However, the radiation level especially power density is still far below the ICNIRP limit.
    Matched MeSH terms: Electromagnetic Fields
  2. Fulltext Role of Phase-Dependent Dielectric Properties of Alumina Nanoparticles in Electromagnetic-Assisted Enhanced Oil Recovery
    Adil M, Lee KC, Zaid HM, Manaka T
    Nanomaterials (Basel), 2020 Oct 06;10(10).
    PMID: 33036153 DOI: 10.3390/nano10101975
    The utilization of metal-oxide nanoparticles in enhanced oil recovery (EOR) has generated considerable research interest to increase the oil recovery. Among these nanoparticles, alumina nanoparticles (Al2O3-NPs) have proved promising in improving the oil recovery mechanism due to their prominent thermal properties. However, more significantly, these nanoparticles, coupled with electromagnetic (EM) waves, can be polarized to reduce water/oil mobility ratio and create disturbances at the oil/nanofluid interface, so that oil can be released from the reservoir rock surfaces and travelled easily to the production well. Moreover, alumina exists in various transition phases (γ, δ, θ, κ, β, η, χ), providing not only different sizes and morphologies but phase-dependent dielectric behavior at the applied EM frequencies. In this research, the oil recovery mechanism under EM fields of varying frequencies was investigated, which involved parameters such as mobility ratio, interfacial tension (IFT) and wettability. The displacement tests were conducted in water-wet sandpacks at 95 °C, by employing crude oil from Tapis. Alumina nanofluids (Al2O3-NFs) of four different phases (α, κ, θ and γ) and particle sizes (25-94.3 nm) were prepared by dispersing 0.01 wt. % NPs in brine (3 wt. % NaCl) together with SDBS as a dispersant. Three sequential injection scenarios were performed in each flooding scheme: (i) preflushes brine as a secondary flooding, (ii) conventional nano/EM-assisted nanofluid flooding, and (iii) postflushes brine to flush NPs. Compared to conventional nanofluid flooding (3.03-11.46% original oil in place/OOIP) as incremental oil recovery, EM-assisted nanofluid flooding provided an increase in oil recovery by approximately 4.12-12.90% of OOIP for different phases of alumina. It was established from these results that the recovery from EM-assisted nanofluid flooding is itself dependent on frequency, which is associated with good dielectric behavior of NPs to formulate the oil recovery mechanism including (i) mobility ratio improvement due to an electrorheological (ER) effect, (ii) interfacial disturbances by the oil droplet deformation, and (iii) wettability alteration by increased surface-free energy.
    Matched MeSH terms: Electromagnetic Fields
  3. Fulltext Effect of nanoparticles concentration on electromagnetic-assisted oil recovery using ZnO nanofluids
    Adil M, Lee K, Mohd Zaid H, A Shukur MF, Manaka T
    PLoS One, 2020;15(12):e0244738.
    PMID: 33382855 DOI: 10.1371/journal.pone.0244738
    Utilization of metal-oxide nanoparticles (NPs) in enhanced oil recovery (EOR) has generated substantial recent research interest in this area. Among these NPs, zinc oxide nanoparticles (ZnO-NPs) have demonstrated promising results in improving oil recovery due to their prominent thermal properties. These nanoparticles can also be polarized by electromagnetic (EM) field, which offers a unique Nano-EOR approach called EM-assisted Nano-EOR. However, the impact of NPs concentrations on oil recovery mechanism under EM field has not been well established. For this purpose, ZnO nanofluids (ZnO-NFs) of two different particle sizes (55.7 and 117.1 nm) were formed by dispersing NPs between 0.01 wt.% to 0.1 wt.% in a basefluid of sodium dodecylbenzenesulfonate (SDBS) and NaCl to study their effect on oil recovery mechanism under the electromagnetic field. This mechanism involved parameters, including mobility ratio, interfacial tension (IFT) and wettability. The displacement tests were conducted in water-wet sandpacks at 95˚C, by employing crude oil from Tapis. Three tertiary recovery scenarios have been performed, including (i) SDBS surfactant flooding as a reference, (ii) ZnO-NFs flooding, and (iii) EM-assisted ZnO-NFs flooding. Compare with incremental oil recovery from surfactant flooding (2.1% original oil in place/OOIP), nanofluid flooding reaches up to 10.2% of OOIP at optimal 0.1 wt.% ZnO (55.7 nm). Meanwhile, EM-assisted nanofluid flooding at 0.1 wt.% ZnO provides a maximum oil recovery of 10.39% and 13.08% of OOIP under EM frequency of 18.8 and 167 MHz, respectively. By assessing the IFT/contact angle and mobility ratio, the optimal NPs concentration to achieve a favorable ER effect and interfacial disturbance is determined, correlated to smaller hydrodynamic-sized nanoparticles that cause strong electrostatic repulsion between particles.
    Matched MeSH terms: Electromagnetic Fields
  4. Fulltext Microwave bio-sensor based on symmetrical split ring resonator with spurline filters for therapeutic goods detection
    Alahnomi RA, Zakaria Z, Ruslan E, Ab Rashid SR, Mohd Bahar AA, Shaaban A
    PLoS One, 2017;12(9):e0185122.
    PMID: 28934301 DOI: 10.1371/journal.pone.0185122
    A novel symmetrical split ring resonator (SSRR) based microwave sensor with spurline filters for detecting and characterizing the properties of solid materials has been developed. Due to the weak perturbation in the interaction of material under test (MUT) and planar microwave sensor, spurline filters were embedded to the SSRR microwave sensor which effectively enhanced Q-factor with suppressing the undesired harmonic frequency. The spurline filter structures force the presented sensor to resonate at a fundamental frequency of 2.2 GHz with the capabilities of suppressing rejected harmonic frequency and miniaturization in circuit size. A wide bandwidth rejection is achieved by using double spurlines filters with high Q-factor achievement (up to 652.94) compared to single spurline filter. The new SSRR sensor with spurline filters displayed desired properties such as high sensitivity, accuracy, and performance with a 1.3% typical percentage error in the measurement results. Furthermore, the sensor has been successfully applied for detecting and characterizing solid materials (such as Roger 5880, Roger 4350, and FR4) and evidently demonstrated that it can suppress the harmonic frequency effectively. This novel design with harmonic suppression is useful for various applications such as food industry (meat, fruit, vegetables), biological medicine (derived from proteins and other substances produced by the body), and Therapeutic goods (antiseptics, vitamins, anti-psychotics, and other medicines).
    Matched MeSH terms: Electromagnetic Fields
  5. Effects of Bluetooth device electromagnetic field on hearing: pilot study
    Balachandran R, Prepageran N, Prepagaran N, Rahmat O, Zulkiflee AB, Hufaida KS
    J Laryngol Otol, 2012 Apr;126(4):345-8.
    PMID: 22310164 DOI: 10.1017/S0022215112000047
    The Bluetooth wireless headset has been promoted as a 'hands-free' device with a low emission of electromagnetic radiation.
    Matched MeSH terms: Electromagnetic Fields/adverse effects*
  6. Fulltext Measurement of extremely low frequency (ELF) magnetic flux in the vicinity of the overhead high voltage transmission line in Universiti Kebangsaan Malaysia
    Faizal Mohamed, Irman Abdul Rahman, Ngu, Thieng Kui, Syazwani Mohd Fadzil, Firdaus Pozi, Amran Ab. Majid, et al.
    Journal of Nuclear and Related Technologies, 2017;14(2):1-10.
    MyJurnal
    Electricity has become one of the necessities for human daily activities. The presence of electric
    current produces electromagnetic fields (EMF) at extremely low frequency (ELF). The problem arises
    when scientists suggests a possible connection between ELF exposure to human health and safety.
    Concerned about the safety and health of students and staff, Universiti Kebangsaan Malaysia (UKM)
    took the initiative to identify possible ELF sources and measure their exposure in various locations
    around the UKM main campus in Bangi. This paper reports the results obtained from the monitoring
    of the magnetic flux density at three identified locations in the vicinity of the overhead high-voltage
    transmission line which transverses the university compound and compare the maximum value results
    with the exposure limit suggested by the International Committee on Non Ionising Radiation
    Protection (ICNIRP) for ELF. Measurements were done with an (Extech) Three Axis
    Electromagnetic Field (EMF) Meter (Model 430826) to determine the magnetic flux density. The
    lateral profile method was applied as the standard measurement methodology. Results showed that the
    maximum value of the magnetic flux density was 12.5 mG, which is below the suggested ICNIRP
    public exposure limit of 1000 mG, or in percentage ratio, 1.25% of ICNIRP public exposure limit.
    Results from the statistical Kruskal-Wallis test showed that there is a significant difference in the
    distributions of the magnetic flux densities at the different locations (P < 0.05). In conclusion, the
    measured locations are still safe for people in short-term exposure. However, long-term exposure
    measurements still need to be done to provide concrete data on the ELF-emission levels in UKM.
    Matched MeSH terms: Electromagnetic Fields
  7. Electromagnetic (EM) absorption reduction in a muscle cube with metamaterial attachment
    Faruque MR, Islam MT, Misran N
    Med Eng Phys, 2011 Jun;33(5):646-52.
    PMID: 21216175 DOI: 10.1016/j.medengphy.2010.12.004
    The purpose of this paper is to calculate the specific absorption rate (SAR) reduction in a muscle cube with metamaterial attachment. The finite-difference time-domain (FDTD) method has been used to evaluate the SAR in a realistic anatomically based model of the muscle cube. In this paper, we have designed the single-negative metamaterials from a periodic arrangement of split ring resonators (SRRs). By properly designing the structural parameter of the SRRs, the effective medium parameter can be tuned negative at the 900 MHz and 1800 MHz bands. Numerical results concerning the SAR values in the muscle cube in the presence of resonators exhibit significant SAR reduction. These results can provide useful information when designing safety-compliant mobile communication equipment.
    Matched MeSH terms: Electromagnetic Fields*
  8. Risk Communication Strategies for Possible Health Risks From Radio-Frequency Electromagnetic Fields (RF-EMF) Emission by Telecommunication Structures
    Fernandez PR, Ng KH, Kaur S
    Health Phys, 2019 06;116(6):835-839.
    PMID: 30844902 DOI: 10.1097/HP.0000000000001037
    There is widespread anxiety and speculation about RF-EMF emissions by telecommunication base stations and structures, as it is perceived by some to be unsafe and a threat to public health. Scientists, medical experts, politicians, journalists, and mobile telecommunication company specialists are involved in an active debate on whether people are immune to RF or if we are gambling with our future. Interviews with 31 individuals from 7 stakeholder groups in Malaysia reveal that the residents' main concerns are that the telecommunication companies do not follow guidelines and as a result the telecommunication structures are constructed close to their homes, which they perceive as a threat to public health. Some residents also do not want these structures because of cultural reasons, while some are jealous over rental income received by the landlords. Meanwhile, the authorities entrusted with safe-guarding public health are involved in a blame game as there is no agency that is clearly in charge. The interviews also highlight that the current risk communication initiatives are more reactive rather than proactive, and that the authorities do not speak in one voice. Based on the outcome of the interviews, eleven recommendations are formulated to improve risk communication initiatives in Malaysia. The recommendations stress on repairing, building, and strengthening trust, because trust in agencies, along with credibility, determines risk communication initiatives' effectiveness. These strategies can also be effectively replicated across regions to deal with contestations over RF-EMF emissions and the impact on health.
    Matched MeSH terms: Electromagnetic Fields/adverse effects*
  9. Analysis of model-based and model-free CEST effect quantification methods for different medical applications
    Foo LS, Yap WS, Hum YC, Manan HA, Tee YK
    J Magn Reson, 2020 01;310:106648.
    PMID: 31760147 DOI: 10.1016/j.jmr.2019.106648
    Chemical exchange saturation transfer (CEST) magnetic resonance imaging (MRI) holds great potential to provide new metabolic information for clinical applications such as tumor, stroke and Parkinson's Disease diagnosis. Many active research and developments have been conducted to translate this emerging MRI technique for routine clinical applications. In general, there are two CEST quantification techniques: (i) model-free and (ii) model-based techniques. The reliability of these quantification techniques depends heavily on the experimental conditions and quality of the collected data. Errors such as noise may lead to misleading quantification results and thus inaccurate diagnosis when CEST imaging becomes a standard or routine imaging scan in the future. This paper investigates the accuracy and robustness of these quantification techniques under different signal-to-noise (SNR) levels and magnetic field strengths. The quantified CEST effect before and after adding random Gaussian White Noise using model-free and model-based quantification techniques were compared. It was found that the model-free technique consistently yielded larger average percentage error across all tested parameters compared to its model-based counterpart, and that the model-based technique could withstand SNR of about 3 times lower than the model-free technique. When applied on noisy brain tumor, ischemic stroke, and Parkinson's Disease clinical data, the model-free technique failed to produce significant differences between normal and abnormal tissue whereas the model-based technique consistently generated significant differences. Although the model-free technique was less accurate and robust, its simplicity and thus speed would still make it a good approximate when the SNR was high (>50) or when the CEST effect was large and well-defined. For more accurate CEST quantification, model-based techniques should be considered. When SNR was low (<50) and the CEST effect was small such as those acquired from clinical field strength scanners, which are generally 3T and below, model-based techniques should be considered over model-free counterpart to maintain an average percentage error of less than 44% even under very noisy condition as tested in this work.
    Matched MeSH terms: Electromagnetic Fields
  10. The effects of metamaterial on electromagnetic fields absorption characteristics of human eye tissues
    Gasmelseed A, Yunus J
    Prog Biophys Mol Biol, 2014 Jan;114(1):8-12.
    PMID: 24239501 DOI: 10.1016/j.pbiomolbio.2013.10.004
    The interaction of a dipole antenna with a human eye model in the presence of a metamaterial is investigated in this paper. The finite difference time domain (FDTD) method with convolutional perfectly matched layer (CPML) formulation have been used. A three-dimensional anatomical model of the human eye with resolution of 1.25 mm × 1.25 mm × 1.25 mm was used in this study. The dipole antenna was driven by modulated Gaussian pulse and the numerical study is performed with dipole operating at 900 MHz. The analysis has been done by varying the size and value of electric permittivity of the metamaterial. By normalizing the peak SAR (1 g and 10 g) to 1 W for all examined cases, we observed how the SAR values are not affected by the different permittivity values with the size of the metamaterial kept fixed.
    Matched MeSH terms: Electromagnetic Fields*
  11. Fulltext Stochastic electromagnetic field propagation- measurement and modelling
    Gradoni G, Russer J, Baharuddin MH, Haider M, Russer P, Smartt C, et al.
    Philos Trans A Math Phys Eng Sci, 2018 Oct 29;376(2134).
    PMID: 30373944 DOI: 10.1098/rsta.2017.0455
    This paper reviews recent progress in the measurement and modelling of stochastic electromagnetic fields, focusing on propagation approaches based on Wigner functions and the method of moments technique. The respective propagation methods are exemplified by application to measurements of electromagnetic emissions from a stirred, cavity-backed aperture. We discuss early elements of statistical electromagnetics in Heaviside's papers, driven mainly by an analogy of electromagnetic wave propagation with heat transfer. These ideas include concepts of momentum and directionality in the realm of propagation through confined media with irregular boundaries. We then review and extend concepts using Wigner functions to propagate the statistical properties of electromagnetic fields. We discuss in particular how to include polarization in this formalism leading to a Wigner tensor formulation and a relation to an averaged Poynting vector.This article is part of the theme issue 'Celebrating 125 years of Oliver Heaviside's 'Electromagnetic Theory''.
    Matched MeSH terms: Electromagnetic Fields
  12. Fulltext Dry Thermotropic Glycolipid Self-Assembly:A Review
    Hashim R, Zahid NI, Velayutham TS, Aripin NFK, Ogawa S, Sugimura A
    J Oleo Sci, 2018 Jun 01;67(6):651-668.
    PMID: 29760332 DOI: 10.5650/jos.ess17261
    Also recognized as carbohydrate liquid crystals, glycolipids are amphiphiles whose basic unit comprises of a sugar group attached to an alkyl chain. Glycolipids are amphitropic, which means these materials form liquid crystal self-assemblies when dry (thermotropic) as well as when dissolved in solvents (lyotropic/surfactants) such as water. Many glycolipids are also naturally derived since these can be found in cell membranes. Their membrane and surfactant functions are largely understood through their lyotropic properties. While glycolipids are expected to play major roles as eco-friendly surfactants in the global surfactant market, their usefulness as thermotropic liquid crystal material is, to date, unknown, due to relatively lack of research performed and data reported in the literature. Understandably since glycolipids are hygroscopic with many hydroxy groups, removing the last trace water is very challenging. In recent time, with careful lyophilization and more consistent characterization technique, some researchers have attempted serious studies into "dry" or anhydrous glycolipids. Motivated by possible developments of novel thermotropic applications, some results from these studies also provide surprising new understanding to support conventional wisdom of the lyotropic systems. Here we review the dry state of glycosides, a family of glycolipids whose sugar headgroup is linked to the lipid chain via a glycosidic oxygen linker. The structure property relationship of both linear and anhydrous Guerbet glycosides will be examined. In particular, how the variation of sugar stereochemistry (e.g. anomer vs. epimer), the chain length and chain branching affect the formation of thermotropic liquid crystals phases, which not only located under equilibrium but also far from equilibrium conditions (glassy phase) are scrutinized. The dry glycolipid assembly has been subjected to electric and magnetic fields and the results show interesting behaviors including a possible transient current generation.
    Matched MeSH terms: Electromagnetic Fields
  13. Fulltext Low-Profile Slotted Metamaterial Antenna Based on Bi Slot Microstrip Patch for 5G Application
    Hoque A, Islam MT, Almutairi AF
    Sensors (Basel), 2020 Jun 11;20(11).
    PMID: 32545228 DOI: 10.3390/s20113323
    A low-profile high-directivity, and double-negative (DNG) metamaterial-loaded antenna with a slotted patch is proposed for the 5G application. The radiated slotted arm as a V shape has been extended to provide a low-profile feature with a two-isometric view square patch structure, which accelerates the electromagnetic (EM) resonance. Besides, the tapered patch with two vertically split parabolic horns and the unit cell metamaterial expedite achieve more directive radiation. Two adjacent splits with meta units enhance the surface current to modify the actual electric current, which is induced by a substrate-isolated EM field. As a result, the slotted antenna shows a 7.14 dBi realized gain with 80% radiation efficiency, which is quite significant. The operation bandwidth is 4.27-4.40 GHz, and characteristic impedance approximately remains the same (50 Ω) to give a VSWR (voltage Standing wave ratio) of less than 2, which is ideal for the expected application field. The overall size of the antenna is 60 × 40 × 1.52 mm. Hence, it has potential for future 5G applications, like Internet of Things (IoT), healthcare systems, smart homes, etc.
    Matched MeSH terms: Electromagnetic Fields
  14. Analysis on the effect of the distances and inclination angles between human head and mobile phone on SAR
    Hossain MI, Faruque MR, Islam MT
    Prog Biophys Mol Biol, 2015 Nov;119(2):103-10.
    PMID: 25863147 DOI: 10.1016/j.pbiomolbio.2015.03.008
    The aim of this paper is to investigate the effects of the distances between the human head and internal cellular device antenna on the specific absorption rate (SAR). This paper also analyzes the effects of inclination angles between user head and mobile terminal antenna on SAR values. The effects of the metal-glass casing of mobile phone on the SAR values were observed in the vicinity of the human head model. Moreover, the return losses were investigated in all cases to mark antenna performance. This analysis was performed by adopting finite-difference time-domain (FDTD) method on Computer Simulation Technology (CST) Microwave Studio. The results indicate that by increasing the distance between the user head and antenna, SAR values are decreased. But the increase in inclination angle does not reduce SAR values in all cases. Additionally, this investigation provides some useful indication for future design of low SAR mobile terminal antenna.
    Matched MeSH terms: Electromagnetic Fields*
  15. Fulltext Quantum Physics Perspective on Electromagnetic and Quantum Fields Inside the Brain
    Idris Z
    Malays J Med Sci, 2020 Feb;27(1):1-5.
    PMID: 32158340 DOI: 10.21315/mjms2020.27.1.1
    Brain energy is associated commonly with electrochemical type of energy. This energy is displayed in the form of electromagnetic waves or better known as brainwaves. This concept is a classical concept (Newtonian) in which the studied object, that is the brain is viewed as a large anatomical object with its functional brainwaves. Another concept which incorporates quantum principles in it can also be used to study the brain. This perspective viewing the brain as purely waves, including its anatomical substrate. Thus, there are two types of energy or field exist in our brain: electromagnetic and quantum fields. Electromagnetic field is thought as dominant energy in purely motor and sensory inputs to our brain, whilst quantum field or energy is perceived as more influential in brain cognitions. The reason for this notion lies in its features which is diffused, non-deterministic, varied, complex and oneness.
    Matched MeSH terms: Electromagnetic Fields
  16. Fulltext Optimizing supercritical antisolvent process parameters to minimize the particle size of paracetamol nanoencapsulated in L-polylactide
    Kalani M, Yunus R, Abdullah N
    Int J Nanomedicine, 2011;6:1101-5.
    PMID: 21698077 DOI: 10.2147/IJN.S18979
    The aim of this study was to optimize the different process parameters including pressure, temperature, and polymer concentration, to produce fine small spherical particles with a narrow particle size distribution using a supercritical antisolvent method for drug encapsulation. The interaction between different process parameters was also investigated.
    Matched MeSH terms: Electromagnetic Fields
  17. Assessment of radiofrequency/microwave radiation emitted by the antennas of rooftop-mounted mobile phone base stations
    Keow MA, Radiman S
    Radiat Prot Dosimetry, 2006;121(2):122-7.
    PMID: 16357026
    Radiofrequency (RF) and microwave (MW) radiation exposures from the antennas of rooftop-mounted mobile telephone base stations have become a serious issue in recent years due to the rapidly evolving technologies in wireless telecommunication systems. In Malaysia, thousands of mobile telephone base stations have been erected all over the country, most of which are mounted on the rooftops. In view of public concerns, measurements of the RF/MW levels emitted by the base stations were carried out in this study. The values were compared with the exposure limits set by several organisations and countries. Measurements were performed at 200 sites around 47 mobile phone base stations. It was found that the RF/MW radiation from these base stations were well below the maximum exposure limits set by various agencies.
    Matched MeSH terms: Electromagnetic Fields/adverse effects*
  18. Graphene oxide and gold nanoparticle based dual platform with short DNA probe for the PCR free DNA biosensing using surface-enhanced Raman scattering
    Khalil I, Yehye WA, Julkapli NM, Rahmati S, Sina AA, Basirun WJ, et al.
    Biosens Bioelectron, 2019 Apr 15;131:214-223.
    PMID: 30844598 DOI: 10.1016/j.bios.2019.02.028
    Surface-enhanced Raman scattering (SERS) based DNA biosensors have considered as excellent, fast and ultrasensitive sensing technique which relies on the fingerprinting ability to produce molecule specific distinct spectra. Unlike conventional fluorescence based strategies SERS provides narrow spectral bandwidths, fluorescence quenching and multiplexing ability, and fitting attribute with short length probe DNA sequences. Herein, we report a novel and PCR free SERS based DNA detection strategy involving dual platforms and short DNA probes for the detection of endangered species, Malayan box turtle (MBT) (Cuora amboinensis). In this biosensing feature, the detection is based on the covalent linking of the two platforms involving graphene oxide-gold nanoparticles (GO-AuNPs) functionalized with capture probe 1 and gold nanoparticles (AuNPs) modified with capture probe 2 and Raman dye (Cy3) via hybridization with the corresponding target sequences. Coupling of the two platforms generates locally enhanced electromagnetic field 'hot spot', formed at the junctions and interstitial crevices of the nanostructures and consequently provide significant amplification of the SERS signal. Therefore, employing the two SERS active substrates and short-length probe DNA sequences, we have managed to improve the sensitivity of the biosensors to achieve a lowest limit of detection (LOD) as low as 10 fM. Furthermore, the fabricated biosensor exhibited sensitivity even for single nucleotide base-mismatch in the target DNA as well as showed excellent performance to discriminate closely related six non-target DNA sequences. Although the developed SERS biosensor would be an attractive platform for the authentication of MBT from diverse samples including forensic and/or archaeological specimens, it could have universal application for detecting gene specific biomarkers for many diseases including cancer.
    Matched MeSH terms: Electromagnetic Fields
  19. Radio frequency electromagnetic radiation (RF-EMR) from GSM (0.9/1.8GHz) mobile phones induces oxidative stress and reduces sperm motility in rats
    Mailankot M, Kunnath AP, Jayalekshmi H, Koduru B, Valsalan R
    Clinics (Sao Paulo), 2009;64(6):561-5.
    PMID: 19578660
    INTRODUCTION: Mobile phones have become indispensable in the daily lives of men and women around the globe. As cell phone use has become more widespread, concerns have mounted regarding the potentially harmful effects of RF-EMR from these devices.

    OBJECTIVE: The present study was designed to evaluate the effects of RF-EMR from mobile phones on free radical metabolism and sperm quality.

    MATERIALS AND METHODS: Male albino Wistar rats (10-12 weeks old) were exposed to RF-EMR from an active GSM (0.9/1.8 GHz) mobile phone for 1 hour continuously per day for 28 days. Controls were exposed to a mobile phone without a battery for the same period. The phone was kept in a cage with a wooden bottom in order to address concerns that the effects of exposure to the phone could be due to heat emitted by the phone rather than to RF-EMR alone. Animals were sacrificed 24 hours after the last exposure and tissues of interest were harvested.

    RESULTS: One hour of exposure to the phone did not significantly change facial temperature in either group of rats. No significant difference was observed in total sperm count between controls and RF-EMR exposed groups. However, rats exposed to RF-EMR exhibited a significantly reduced percentage of motile sperm. Moreover, RF-EMR exposure resulted in a significant increase in lipid peroxidation and low GSH content in the testis and epididymis.

    CONCLUSION: Given the results of the present study, we speculate that RF-EMR from mobile phones negatively affects semen quality and may impair male fertility.

    Matched MeSH terms: Electromagnetic Fields/adverse effects*
  20. Fulltext Effect of Short-Term Mobile Phone Base Station Exposure on Cognitive Performance, Body Temperature, Heart Rate and Blood Pressure of Malaysians
    Malek F, Rani KA, Rahim HA, Omar MH
    Sci Rep, 2015;5:13206.
    PMID: 26286015 DOI: 10.1038/srep13206
    Individuals who report their sensitivity to electromagnetic fields often undergo cognitive impairments that they believe are due to the exposure of mobile phone technology. The aim of this study is to clarify whether short-term exposure at 1 V/m to the typical Global System for Mobile Communication and Universal Mobile Telecommunications System (UMTS) affects cognitive performance and physiological parameters (body temperature, blood pressure and heart rate). This study applies counterbalanced randomizing single blind tests to determine if sensitive individuals experience more negative health effects when they are exposed to base station signals compared with sham (control) individuals. The sample size is 200 subjects with 50.0% Idiopathic Environmental Intolerance attributed to electromagnetic fields (IEI-EMF) also known as sensitive and 50.0% (non-IEI-EMF). The computer-administered Cambridge Neuropsychological Test Automated Battery (CANTAB eclipse(TM)) is used to examine cognitive performance. Four tests are chosen to evaluate Cognitive performance in CANTAB: Reaction Time (RTI), Rapid Visual Processing (RVP), Paired Associates Learning (PAL) and Spatial Span (SSP). Paired sample t-test on the other hand, is used to examine the physiological parameters. Generally, in both groups, there is no statistical significant difference between the exposure and sham exposure towards cognitive performance and physiological effects (P's > 0.05).
    Matched MeSH terms: Electromagnetic Fields
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