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  1. Ng KH, Brady Z, Ng AH, Soh HS, Chou YH, Varma D
    J Med Imaging Radiat Oncol, 2021 Jul;65(4):464-470.
    PMID: 33606359 DOI: 10.1111/1754-9485.13165
    More than half of the world's population live in Asia-Pacific. This region is culturally diverse, with significant disparities in terms of socio-economic status, provision of health care and access to advanced technology. The medical use of ionising radiation is increasing worldwide and similarly within the Asia-Pacific region. In this paper, we highlight the current status in usage of ionising radiation in medicine in the region, and review the legal framework, implementation and activities in radiation protection. Asia-Pacific countries are active in strengthening radiation protection by promoting education and training. Various projects and activities initiated by international organisations such as the IAEA, WHO and ICRP have provided stimulation in the region, but more work is needed to continue to improve protection practices.
    Matched MeSH terms: Radiation Protection*; Radiation Oncology*
  2. Kohli S, Bhatia S
    Eur J Prosthodont Restor Dent, 2016 12;24(4):170.
    PMID: 28510369 DOI: 10.1922/EJPRD_01650kohli01
    Sir, I write in regard to Nayar S et al article 'The Effect of a Radiation Positioning Stent (RPS) in the Reduction of Radiation Dosage to the Opposing Jaw and Maintenance of Mouth opening after Radiation Therapy'. I wholeheartedly agree to that patients undergoing radio-therapy who had an Radiation Positioning Stent (RPS) would show a significant reduction in radiation dosage to the opposing jaw and maintained their mouth opening in the short-term. As we know that oral cancer has emerged to be one of most deadliest cancer nowadays.
    Matched MeSH terms: Radiation Dosage; Radiation Injuries*; Radiation Protection*
  3. Johary YH, Albarakati S, AlSohaim A, Aamry A, Aamri H, Tamam N, et al.
    Appl Radiat Isot, 2023 Mar;193:110648.
    PMID: 36669265 DOI: 10.1016/j.apradiso.2023.110648
    Occupational radiation exposure can occur due to various human activities, including the use of radiation in medicine. Occupationally exposed personnel surpassing 7.4 millions, and respresent the biggest single group of employees who are exposed to artificial radiation sources at work. This study compares the occupational radiation dose levels for 145 workers in four different hospitals located in the Aseer region in Saudi Arabia. The occupational exposure was quantified using thermoluminescence dosimeters (TLD-100). The levels of annual occupational exposures in targeted hospitals were calculated and compared with the levels of the international atomic energy agency (IAEA) Safety Standards. An average yearly cumulative dose for the two consecutive years. The average, highest and lowest resulted occupational doses under examination in this work is 1.42, 3.9 mSv and 0.72 for workers in various diagnostic radiology procedures. The resulted annual effective dose were within the IAEA approved yearly dose limit for occupational exposure of workers over 18, which is 20 mSv. Staff should be monitored on a regular basis, according to current practice, because their annual exposure may surpass 15% of the annual effective doses.
    Matched MeSH terms: Radiation Exposure*; Radiation Dosage; Radiation Injuries*
  4. Al-Bawri SS, Islam MS, Wong HY, Jamlos MF, Narbudowicz A, Jusoh M, et al.
    Sensors (Basel), 2020 Jan 14;20(2).
    PMID: 31947533 DOI: 10.3390/s20020457
    A multiband coplanar waveguide (CPW)-fed antenna loaded with metamaterial unit cell for GSM900, WLAN, LTE-A, and 5G Wi-Fi applications is presented in this paper. The proposed metamaterial structure is a combination of various symmetric split-ring resonators (SSRR) and its characteristics were investigated for two major axes directions at (x and y-axis) wave propagation through the material. For x-axis wave propagation, it indicates a wide range of negative refractive index in the frequency span of 2-8.5 GHz. For y-axis wave propagation, it shows more than 2 GHz bandwidth of near-zero refractive index (NZRI) property. Two categories of the proposed metamaterial plane were applied to enhance the bandwidth and gain. The measured reflection coefficient (S11) demonstrated significant bandwidths increase at the upper bands by 4.92-6.49 GHz and 3.251-4.324 GHz, considered as a rise of 71.4% and 168%, respectively, against the proposed antenna without using metamaterial. Besides being high bandwidth achieving, the proposed antenna radiates bi-directionally with 95% as the maximum radiation efficiency. Moreover, the maximum measured gain reaches 6.74 dBi by a 92.57% improvement compared with the antenna without using metamaterial. The simulation and measurement results of the proposed antenna show good agreement.
    Matched MeSH terms: Radiation; Electromagnetic Radiation
  5. Ali Esmail B, Majid HA, Zainal Abidin Z, Haimi Dahlan S, Himdi M, Dewan R, et al.
    Materials (Basel), 2020 Jan 26;13(3).
    PMID: 31991912 DOI: 10.3390/ma13030582
    In this research, a reconfigurable metamaterial (MM) structure was designed using a millimeter-wave (MMW) band with two configurations that exhibit different refractive indices. These two MM configurations are used to guide the antenna's main beam in the desired direction in the 5th generation (5G) band of 28 GHz. The different refractive indices of the two MM configurations created phase change for the electromagnetic (EM) wave of the antenna, which deflected the main beam. A contiguous squares resonator (CSR) is proposed as an MM structure to operate at MMW band. The CSR is reconfigured using three switches to achieve two MM configurations with different refractive indices. The simulation results of the proposed antenna loaded by MM unit cells demonstrate that the radiation beam is deflected by angles of +30° and -27° in the E-plane, depending on the arrangement of the two MM configurations on the antenna substrate. Furthermore, these deflections are accompanied by gain enhancements of 1.9 dB (26.7%) and 1.5 dB (22.4%) for the positive and negative deflections, respectively. The reflection coefficients of the MM antenna are kept below -10 dB for both deflection angles at 28 GHz. The MM antennas are manufactured and measured to validate the simulated results.
    Matched MeSH terms: Radiation; Electromagnetic Radiation
  6. Rizk C, Askounis P, Okyar HB, Sangau JK, Baradaran S, Al Fares E, et al.
    Radiat Prot Dosimetry, 2020 Aug 28;190(2):217-225.
    PMID: 32696972 DOI: 10.1093/rpd/ncaa093
    This paper presents the results of the evaluation of the uncertainty in measurement of the personal dose equivalent, Hp(10), at nine individual monitoring services (IMSs) in Asia and the Pacific region. Different types of passive dosemeters were type-tested according to the International Electrotechnical Commission 62387 requirements. The uncertainty in measurement was calculated using the Guide to the Expression of Uncertainty in Measurement approach. Expanded uncertainties ranged between 24 and 86% (average = 38%) for Hp(10) values around 1 mSv and between 14 and 40% (average = 27%) for doses around the annual dose limit, Hp(10) = 20 mSv. The expanded uncertainties were lower than the 1.5 factor in either direction proposed by the International Commission on Radiological Protection for doses near the relevant dose limits. This indicates an acceptable level of uncertainty for all participating IMSs. Uncertainty evaluation will help the IMSs to acknowledge the accuracy of their measurements.
    Matched MeSH terms: Radiation Dosage; Radiation Monitoring*
  7. Aliyu AS, Ibrahim U, Akpa CT, Garba NN, Ramli AT
    Isotopes Environ Health Stud, 2015;51(3):448-68.
    PMID: 25848858 DOI: 10.1080/10256016.2015.1026339
    Nasarawa State is located in north central Nigeria and it is known as Nigeria's home of solid minerals. It is endowed with barite, copper, zinc, tantalite and granite. Continuous releases of mining waste and tailings into the biosphere may result in a build-up of radionuclides in air, water and soil. This work therefore aims to measure the activity concentration levels of primordial radionuclides in the soil/sediment samples collected from selected mines of the mining areas of Nasarawa State. The paper also assesses the radiological and radio ecological impacts of mining activities on the residents of mining areas and their environment. The activity concentrations of primordial radionuclides ((226)Ra, (232)Th and (40)K) in the surface soils/sediment samples were determined using sodium iodide-thallium gamma spectroscopy. Seven major mines were considered with 21 samples taken from each of the mines for radiochemistry analysis. The human health hazard assessment was conducted using regulatory methodologies set by the United Nations Scientific Committee on the Effects of Atomic Radiation, while the radio ecological impact assessment was conducted using the ERICA tool v. 1.2. The result shows that the activity concentrations of (40)K in the water ways of the Akiri copper and the Azara barite mines are 60 and 67% higher than the world average value for (40)K, respectively. In all mines, the annual effective dose rates (mSv y(-1)) were less than unity, and a maximum annual gonadal dose of 0.58 mSv y(-1) is received at the Akiri copper mine, which is almost twice the world average value for gonadal dose. The external hazard indices for all the mines were less than unity. Our results also show that mollusc-gastropod, insect larvae, mollusc-bivalve and zooplankton are the freshwater biotas with the highest dose rates ranging from 5 to 7 µGy h(-1). These higher dose rates could be associated with zinc and copper mining at Abuni and Akiri, respectively. The most exposed terrestrial reference organisms are lichen and bryophytes. In all cases, the radio ecological risks are not likely to be discernible. This paper presents a pioneer data for ecological risk from ionizing contaminants due to mining activity in Nasarawa State, Nigeria. Its methodology could be adopted for future work on radioecology of mining.
    Matched MeSH terms: Radiation Exposure*; Background Radiation*; Radiation Monitoring*
  8. Lam ES
    Med J Malaysia, 1979 Dec;34(2):171-3.
    PMID: 548723
    Matched MeSH terms: Radiation Dosage; Radiation Injuries/prevention & control*; Radiation Monitoring; Radiation Protection/methods
  9. Sanusi MSM, Ramli AT, Hassan WMSW, Lee MH, Izham A, Said MN, et al.
    Environ Int, 2017 07;104:91-101.
    PMID: 28412010 DOI: 10.1016/j.envint.2017.01.009
    Kuala Lumpur has been undergoing rapid urbanisation process, mainly in infrastructure development. The opening of new township and residential in former tin mining areas, particularly in the heavy mineral- or tin-bearing alluvial soil in Kuala Lumpur, is a contentious subject in land-use regulation. Construction practices, i.e. reclamation and dredging in these areas are potential to enhance the radioactivity levels of soil and subsequently, increase the existing background gamma radiation levels. This situation is worsened with the utilisation of tin tailings as construction materials apart from unavoidable soil pollutions due to naturally occurring radioactive materials in construction materials, e.g. granitic aggregate, cement and red clay brick. This study was conducted to assess the urbanisation impacts on background gamma radiation in Kuala Lumpur. The study found that the mean value of measured dose rate was 251±6nGyh-1(156-392nGyh-1) and 4 times higher than the world average value. High radioactivity levels of238U (95±12Bqkg-1),232Th (191±23Bqkg-1,) and40K (727±130Bqkg-1) in soil were identified as the major source of high radiation exposure. Based on statistical ANOVA, t-test, and analyses of cumulative probability distribution, this study has statistically verified the dose enhancements in the background radiation. The effective dose was estimated to be 0.31±0.01mSvy-1per man. The recommended ICRP reference level (1-20mSvy-1) is applicable to the involved existing exposure situation in this study. The estimated effective dose in this study is lower than the ICRP reference level and too low to cause deterministic radiation effects. Nevertheless based on estimations of lifetime radiation exposure risks, this study found that there was small probability for individual in Kuala Lumpur being diagnosed with cancer and dying of cancer.
    Matched MeSH terms: Radiation Exposure/analysis*; Background Radiation*; Radiation Dosage; Radiation Monitoring
  10. Abu Amat, N. H., Mohd Taib, N. H., Supardi, N. F., Yusoff, M. N. S.
    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: Radiation, Ionizing; Radiation, Nonionizing; Electromagnetic Radiation
  11. Ligam, Alfred Sanggau, Zarina Masood, Mohd Fairus Abdul Farid, Ahmad Nabil Abd Rahim, Nurhayati Ramli, Mohammad Suhaimi Kassim
    MyJurnal
    Radiation Monitoring System aims to limit the exposure dose to personnel to the lowest level
    referring to the concept of ALARA (As Low As Reasonably Achievable). Atomic Energy Licensing
    (Basic Safety Radiation Protection) Regulations 2010 is useful to control employee and public
    radiation protection program and guideline. This paper discussed the methodology and
    implementation of the radiation protection program at PUSPATI TRIGA Reactor (RTP) which is
    implemented in Nuklear Malaysia, Complex Bangi.
    Matched MeSH terms: Radiation; Radiation Monitoring; Radiation Protection
  12. Pradhoshini KP, Priyadharshini M, Santhanabharathi B, Ahmed MS, Parveen MHS, War MUD, et al.
    Environ Toxicol Pharmacol, 2023 Apr;99:104091.
    PMID: 36870406 DOI: 10.1016/j.etap.2023.104091
    Ionizing radiation from radionuclides impacts marine aquatic biota and the scope of investigation must be wider than just invertebrates. We intend to detail and illustrate numerous biological effects that occur in both aquatic vertebrates and invertebrates, at various dose rates from all three kinds of ionizing radiation. The characteristics of radiation sources and dosages that would most effectively generate the intended effects in the irradiated organism were assessed once the biological differentiation between vertebrates and invertebrates was determined through multiple lines of evidence. We contend that invertebrates are still more radiosensitive than vertebrates, due to their small genome size, rapid reproduction rates and lifestyle, which help them to compensate for the effects of radiation induced declines in fecundity, life span and individual health. We also identified various research gaps in this field and suggest future directions to be investigated to remedy the lack of data available in this area.
    Matched MeSH terms: Radiation Tolerance; Radiation, Ionizing*
  13. Jaffar FHF, Osman K, Ismail NH, Chin KY, Ibrahim SF
    Tohoku J. Exp. Med., 2019 07;248(3):169-179.
    PMID: 31353326 DOI: 10.1620/tjem.248.169
    Extensive use of Wi-Fi has contributed to radiofrequency electromagnetic radiation (RF-EMR) pollution in environment. Various studies have been conducted to evaluate the effect of RF-EMR emitted by Wi-Fi transmitter on male reproduction health. However, there are conflicting findings between studies. Thus, this review aims to elucidate the possible effects of 2.45 GHz Wi-Fi exposure on both animal and human male reproductive system. A computerized database search performed through MEDLINE via Ovid and PUBMED with the following set of keywords: 'Wi-Fi or WiFi or wireless fidelity or Wi-Fi router or WiFi router or electromagnetic or radiofrequency radiation' AND 'sperm or spermatozoa or spermatogenesis or semen or seminal plasma or testes or testis or testosterone or male reproduction' had returned 526 articles. Only 17 studies conformed to pre-set inclusion criterion. Additional records identified through Google Scholar and reviewed article further revealed six eligible articles. A total of 23 articles were used for data extraction, including 15 studies on rats, three studies on mice, and five studies on human health. Sperm count, motility and DNA integrity were the most affected parameters when exposed to RF-EMR emitted by Wi-Fi transmitter. Unfortunately, sperm viability and morphology were inconclusive. Structural and/or physiological analyses of the testes showed degenerative changes, reduced testosterone level, increased apoptotic cells, and DNA damage. These effects were mainly due to the elevation of testicular temperature and oxidative stress activity. In conclusion, exposure towards 2.45 GHz RF-EMR emitted by Wi-Fi transmitter is hazardous on the male reproductive system.
    Matched MeSH terms: Genitalia, Male/radiation effects*; Electromagnetic Radiation*
  14. Bohari A, Hashim S, Mohd Mustafa SN
    Radiat Prot Dosimetry, 2020 Jun 24;188(3):397-402.
    PMID: 31950168 DOI: 10.1093/rpd/ncz299
    Radiation scattered throughout the room during fluoroscopy-guided interventional (FGI) procedures was quantified at different locations using nanoDot optically stimulated luminescence dosemeters. All the tube angulation imaging shows that the radiation spectrum resembled a single peak distribution. The left anterior oblique 90° shows the highest single peak distribution (28.65 mSv/h). The single peak distribution for standard anteroposterior, left anterior oblique 45° and right anterior oblique 45° imaging was 13.32, 22.99 and 17.40 mSv/h, respectively. All tube angulation shows that the position of the interventional radiologist experienced a higher radiation level compared to other staffs. The doses of radiation varied widely around the perimeter of the patient's table and changed in accordance to imaging angles during procedures. Knowledge pertaining to radiation exposure levels is integral in order to avoid adverse risks, particularly among staff.
    Matched MeSH terms: Radiation Exposure*; Radiation Dosage; Scattering, Radiation
  15. Omar, M., Sulaiman, I., Hassan, A.
    MyJurnal
    The measurements of absorbed dose rate in air around amang plant buildings were carried out using a scintillation detector. It was found that the mean radiation levels at seven amang plants were in the range of 1.6 – 5.5 µGy h -1. The individual maximum value measured was 56 µGy h -1. The annual dose to a worker transporting the minerals to the plant was estimated to be 1.5 mSv y -1.
    Matched MeSH terms: Radiation
  16. Tan D, Mohamad Salleh SA, Manan HA, Yahya N
    J Med Imaging Radiat Oncol, 2023 Aug;67(5):564-579.
    PMID: 37309680 DOI: 10.1111/1754-9485.13546
    INTRODUCTION: Delta-radiomics models are potentially able to improve the treatment assessment than single-time point features. The purpose of this study is to systematically synthesize the performance of delta-radiomics-based models for radiotherapy (RT)-induced toxicity.

    METHODS: A literature search was performed following the PRISMA guidelines. Systematic searches were performed in PubMed, Scopus, Cochrane and Embase databases in October 2022. Retrospective and prospective studies on the delta-radiomics model for RT-induced toxicity were included based on predefined PICOS criteria. A random-effect meta-analysis of AUC was performed on the performance of delta-radiomics models, and a comparison with non-delta radiomics models was included.

    RESULTS: Of the 563 articles retrieved, 13 selected studies of RT-treated patients on different types of cancer (HNC = 571, NPC = 186, NSCLC = 165, oesophagus = 106, prostate = 33, OPC = 21) were eligible for inclusion in the systematic review. Included studies show that morphological and dosimetric features may improve the predictive model performance for the selected toxicity. Four studies that reported both delta and non-delta radiomics features with AUC were included in the meta-analysis. The AUC random effects estimate for delta and non-delta radiomics models were 0.80 and 0.78 with heterogeneity, I2 of 73% and 27% respectively.

    CONCLUSION: Delta-radiomics-based models were found to be promising predictors of predefined end points. Future studies should consider using standardized methods and radiomics features and external validation to the reviewed delta-radiomics model.

    Matched MeSH terms: Radiation Injuries*; Radiation Oncology*
  17. Sanusi MS, Ramli AT, Gabdo HT, Garba NN, Heryanshah A, Wagiran H, et al.
    J Environ Radioact, 2014 Sep;135:67-74.
    PMID: 24787672 DOI: 10.1016/j.jenvrad.2014.04.004
    A terrestrial gamma radiation survey for the state of Selangor, Kuala Lumpur and Putrajaya was conducted to obtain baseline data for environmental radiological health practices. Based on soil type, geological background and information from airborne survey maps, 95 survey points statistically representing the study area were determined. The measured doses varied according to geological background and soil types. They ranged from 17 nGy h(-1) to 500 nGy h(-1). The mean terrestrial gamma dose rate in air above the ground was 182 ± 81 nGy h(-1). This is two times higher than the average dose rate of terrestrial gamma radiation in Malaysia which is 92 nGy h(-1) (UNSCEAR 2000). An isodose map was produced to represent exposure rate from natural sources of terrestrial gamma radiation.
    Matched MeSH terms: Radiation Monitoring*
  18. Mohd Asri MT, Elias S, Iskandar SM, Abd Halim S, Jumiah H, Zaki AR, et al.
    Med J Malaysia, 2004 May;59 Suppl B:139-40.
    PMID: 15468857
    The aim of this work was to study radiation and the effects of temperature on conductivity properties of polyvinyl alcohol (PVA)-based potassium hydroxide (KOH) and propylene carbonate (PC), where the ionic conduction preferentially occurs in the amorphous phase by free radicals ions through gamma-irradiation. Alkaline composite polymer electrolyte (ACPE) consisting of PVA, KOH and PC of different concentration ratios were prepared by solvent-casting technique. The ACPE were irradiated with different doses from 5 kGy up to 200 kGy. The conductivity properties of the electrolyte films were measured at different frequencies in the range 20 Hz to 1 MHz using LCR meter. The results showed that the conductivity properties were dependent on the radiation dose, temperature and the concentration of the polymer blends.
    Matched MeSH terms: Dose-Response Relationship, Radiation; Electrolytes/radiation effects*; Hydroxides/radiation effects*; Polymers/radiation effects*; Polyvinyl Alcohol/radiation effects*; Propane/radiation effects*; Potassium Compounds/radiation effects*
  19. Mustafa IS, Kamari HM, Yusoff WM, Aziz SA, Rahman AA
    Int J Mol Sci, 2013;14(2):3201-14.
    PMID: 23380963 DOI: 10.3390/ijms14023201
    Spectrophotometric studies of lead borotellurite glasses were carried out before and after gamma irradiation exposure. The increasing peak on the TeO(4) bi-pyramidal arrangement and TeO(3+1) (or distorted TeO(4)) is due to augmentation of irradiation dose which is attributed to an increase in degree of disorder of the amorphous phase. The structures of lead tellurate contain Pb(3)TeO(6) consisting of TeO(3) trigonal pyramid connected by PbO(4) tetragonal forming a three-dimensional network. The decrease of glass rigidity is due to irradiation process which is supported by the XRD diffractograms results. The decreasing values of absorption edge indicate that red shift effect occur after irradiation processes. A shift in the optical absorption edge attributed to an increase of the conjugation length. The values of optical band gap, E(opt) were calculated and found to be dependent on the glass composition and radiation exposure. Generally, an increase and decrease in Urbach's energy can be considered as being due to an increase in defects within glass network.
    Matched MeSH terms: Radiation Exposure; Radiation Dosage
  20. Abdul Sani SF, Othman MHU, Alqahtani A, Almugren KS, Alkallas FH, Bradley DA
    PLoS One, 2020;15(12):e0241550.
    PMID: 33378398 DOI: 10.1371/journal.pone.0241550
    For x- and gamma- irradiations delivering entrance doses from 2- up to 1000 Gy to commercial 1.0 mm thick borosilicate glass microscope slides, study has been made of their thermoluminescence yield. With an effective atomic number of 10.6 (approximating bone equivalence), photon energy dependency is apparent in the low x-ray energy range, with interplay between the photoelectric effect and attenuation. As an example, over the examined dose range, at 120 kVp the photon sensitivity has been found to be some 5× that of 60Co gamma irradiations, also with repeatability to within ~1%. The glow-curves, taking the form of a single prominent broad peak, have been deconvolved yielding at best fit a total of five peaks, the associated activation energies and frequency factors also being obtained. The results indicate borosilicate glass slides to offer promising performance as a low-cost passive radiation dosimeter, with utility for both radiotherapy and industrial applications.
    Matched MeSH terms: Radiation Oncology; Radiation Dosimeters
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