Displaying publications 161 - 180 of 712 in total

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  1. Hashim AK, Hatif AR, Ahmed NM, Wadi IA, Al Qaaod AA
    Appl Radiat Isot, 2021 Jan;167:109410.
    PMID: 33065401 DOI: 10.1016/j.apradiso.2020.109410
    Radon and progeny concentration measurements in various drink samples are intrinsically important for assessing the health risks resulting from daily consumption of these drinks. In this study the comparison between two Solid State Nuclear Track Detectors (SSNTDs), the CR-39 and the CN-85 has been conducted for the purpose of evaluating the radon concentration, annual effective dose, the rate of exhalation of radon and the effective radium content in thirty-two different samples of soft drink, water, and milk available in the local Iraq markets. The results showed that there are significant differences in the measurement results for the two detectors. The annual effective dose of the investigated samples is still below the limit of International Commission on Radiological Protection (ICRP) recommendation in the measurements of both detectors.
    Matched MeSH terms: Radiation Monitoring/methods
  2. Alkhorayef M, Sulieman A, Babikir E, Daar E, Alnaaimi M, Alduaij M, et al.
    Appl Radiat Isot, 2018 Aug;138:14-17.
    PMID: 28830729 DOI: 10.1016/j.apradiso.2017.08.010
    A pacemaker, which is used for heart resynchronization with electrical impulses, is used to manage many clinical conditions. Recently, the frequency of pacemaker implantation procedures has increased to more than 50% worldwide. During this procedure, patients can be exposed to excessive radiation exposure. Wide range of doses has been reported in previous studies, suggesting that optimization of this procedure has not been fulfilled yet. The current study evaluated patient radiation exposure during cardiac pacemaker procedures and quantified the patient effective dose. A total of 145 procedures were performed for five pacemaker procedures (VVI, VVIR, VVD, VVDR, and DDDR) at two hospitals. Patient doses were measured using the kerma-area product meter. Effective doses were estimated using software based on Monte Carlo simulation from the National Radiological Protection Board (NRPB, now The Health Protection Agency). The effective dose values were used to estimate cancer risk from the pacemaker procedure. Patient demographic data and exposure parameters for fluoroscopy and radiography were quantified. The mean patient doses ± SD per procedure (Gycm2) for VVI, VVIR, VVD, VVDR, and DDDR were 1.52 ± 0.13 (1.43-1.61), 3.28 ± 2.34 (0.29-8.73), 3.04 ± 1.67 (1.57-4.86), 6.04 ± 2.326 3.29-8.58), and 8.8 ± 3.6 (4.5-26.20), respectively. The overall patient effective dose was 1.1mSv per procedure. It is obvious that the DDDR procedure exposed patients to the highest radiation dose. Patient dose variation can be attributed to procedure type, exposure parameter settings, and fluoroscopy time. The results of this study showed that patient doses during different pacemaker procedures are lower compared to previous reported values. Patient risk from pacemaker procedure is low, compared to other cardiac interventional procedures. Patients' exposures were mainly influenced by the type of procedures and the clinical indication.
    Matched MeSH terms: Radiation Exposure/analysis; Radiation Exposure/prevention & control; Neoplasms, Radiation-Induced/etiology; Radiation Dosage; Radiation Protection/methods
  3. Hashim S, Musa Y, Ghoshal SK, Ahmad NE, Hashim IH, Yusop M, et al.
    Appl Radiat Isot, 2018 May;135:7-11.
    PMID: 29353759 DOI: 10.1016/j.apradiso.2018.01.010
    The performance of optically stimulated luminescence dosimeters (OSLDs, Al2O3:C) was evaluated in terms of the operational quantity of HP(10) in Co-60 external beam teletherapy unit. The reproducibility, signal depletion, and dose linearity of each dosimeter was investigated. For ten repeated readouts, each dosimeter exposed to 50mSv was found to be reproducible below 1.9 ± 3% from the mean value, indicating good reader stability. Meanwhile, an average signal reduction of 0.5% per readout was found. The dose response revealed a good linearity within the dose range of 5-50mSv having nearly perfect regression line with R2 equals 0.9992. The accuracy of the measured doses were evaluated in terms of operational quantity HP(10), wherein the trumpet curve method was used respecting the 1990 International Commission on Radiological Protection (ICRP) standard. The accuracy of the overall measurements from all dosimeters was discerned to be within the trumpet curve and devoid of outlier. It is established that the achieved OSL Al2O3:C dosimeters are greatly reliable for equivalent dose assessment.
    Matched MeSH terms: Radiation Dosage; Radiation Dosimeters
  4. Olatunji MA, Khandaker MU, Nwankwo VUJ, Idris AM
    Radiat Environ Biophys, 2022 Nov;61(4):597-608.
    PMID: 36175773 DOI: 10.1007/s00411-022-00993-3
    Proper documentation of baseline radiation data of different environments is an important step toward adequate environmental monitoring, and it provides quick means to quantitatively check and determine possible radionuclide contamination by anthropogenic sources. Besides, such documentation is useful for decision making processes, assessment of dose rates to the public, epidemiological studies, and environmental regulations. This review summarizes the results of studies conducted on radioactivity in Nigerian environments. For most soil samples, the levels of radioactivity are well within the world averages of 33, 45, and 420 Bq kg-1 for 226Ra, 232Th and 40K, respectively. Other soil samples from regions such as Abeokuta in the southwest, and Jos in the northcentral have been described as high background radiation areas with radioactivity values comparable with those obtained from known high background radiation areas such as the Odisha (formerly Orissa) coast in India (with values reported as 350, 2,825, and 180 Bq kg-1 for 238U/226Ra, 232Th, and 40K, respectively). In some parts of Nigeria, surface and underground water sources used for drinking and other purposes also present elevated levels of 226Ra above the world range of 0.01 to 0.1 Bq l-1 and the tolerable levels recommended by the World Health Organization and U.S. Environmental Protection Agency. Corresponding radiation doses due to measured radioactivities from different environments were estimated and compared with those reported in similar studies around the world. More so, the human and environmental health hazards that might be associated with the reported radioactivity in different environmental settings are discussed. The present report is expected to support authorities in developing appropriate regulations to protect the public from radiation exposure arising from environmental radioactivity. The report also examines other areas of consideration for future studies to ensure adequate radiation monitoring in Nigeria.
    Matched MeSH terms: Background Radiation; Radiation Dosage
  5. Ng SY, Eh Suk VR, Gew LT
    J Cosmet Dermatol, 2022 Nov;21(11):5409-5444.
    PMID: 35723888 DOI: 10.1111/jocd.15170
    BACKGROUND: Excessive exposure to ultraviolet radiation has harmful effects on human skin. At present, synthetic and mineral types of sunscreens used to protect against these harmful damages have been reported to cause negative health and environmental effects. The studies involving characterization and isolation of phytoconstituents from natural botanical sources are important to discover their potential beneficial effects on sunscreen development AIM: This systematic review provides specific and compiled information on the photoprotective properties of natural botanical sources for sunscreen development. The efforts in research and innovation are essential to ensure the safety and sustainability of plant-based sunscreen products.

    METHODS: In this review, a total of 35 articles were selected using the Scopus database based on the inclusion and exclusion criteria RESULT: The significant correlation between total phenolic content, total flavonoid content, antioxidant activities, and sun protection factor were shown in these studies which confirmed the potential benefits of natural plants in sunscreen development.

    CONCLUSIONS: In addition, natural botanical sources also exhibit excellent anti-tyrosinase, anti-aging, and anti-inflammatory activities. However, the biological activities of plants were dependent on the solvents used for extraction.

    Matched MeSH terms: Skin/radiation effects
  6. Garba NN, Abdulkadir M, Nasiru R, Saleh MA, Bello S, Khandaker MU, et al.
    Isotopes Environ Health Stud, 2023 Mar;59(1):112-125.
    PMID: 36735938 DOI: 10.1080/10256016.2023.2172001
    Terrestrial gamma radiation dose (TGRD) rates were measured in situ from different locations in Katsina State, Nigeria, using a portable radiation survey metre based on geological formations and soil types. The measured TGRD rates ranged from 45 to 271 nGyh-1 with an average value of 116 ± 1 nGyh-1. Geological formation (silicified sheared rock) and soil type (lithosols and ferruginous crusts and ferruginous tropical soils) appeared to have the highest mean TGRD values of 163 and 134 nGyh-1 with sandstone geological formation and alluvial and hydromorphic soils having the lowest TGRD with values of 80 and 61 nGyh-1, respectively. One way ANOVA results shows that the tested null hypothesis was rejected. Thus, indicating that there exists a strong relationship between the various geological formations, soil types with the measured TGRD values based on the alternate hypothesis. Human health hazard indices like annual effective dose equivalent (AEDE), lifetime outdoor annual equivalent dose, and relative excess lifetime outdoor cancer risk associated with the mean TGRD of the study area were also calculated and found to be 0.711, 9.955 mSv, and 5.79 × 10-4, respectively. These values were higher than the world average values but favourable compared with the safety limits recommended by ICRP.
    Matched MeSH terms: Background Radiation; Radiation Dosage
  7. Siraz MMM, Das SK, Mondol MS, Alam MS, Al Mahmud J, Rashid MB, et al.
    Environ Monit Assess, 2023 Apr 17;195(5):579.
    PMID: 37067680 DOI: 10.1007/s10661-023-11223-8
    Bangladesh is a rapidly developing country, which is vulnerable to various types of pollution due to the large-scale industrial and associated human activities that might potentially affect the locally harvested foodstuffs. Therefore, the transfer factor is an essential tool to assess the safety of foodstuffs due to the presence of natural radioactivity in environmental matrix and/or strata. This is a first study of its kind conducted in a well-known region for mango farming in Bangladesh, measuring the uptake of naturally occurring radioactive materials (NORMs) by grass and mango from soil to assess the ingestion doses to humans. The HPGe gamma-ray detector was used to determine the concentrations of NORMs in samples of soil (20), grass (10), and mango (10), which were then used to calculate the transfer factors of soil to grass and soil to mango. Average activity concentrations of 226Ra, 232Th, and 40K in associated soil samples (47.27 ± 4.10, 64.49 ± 4.32, 421.60 ± 28.85) of mango and 226Ra and 232Th in associated soil samples (45.07 ± 3.93, 52.17 ± 3.95) of grass were found to exceed the world average values. The average transfer factors (TFs) for mango were obtained in the order of 40K(0.80) > 226Ra (0.61) > 232Th (0.31), and for grass, it shows the order of 40K (0.78) > 232Th (0.64) > 226Ra (0.56). However, a few values (3 mango samples and 3 grass samples) of the estimated TFs exceeded the recommended limits. Moreover, Bangladesh lacks the transfer factors for most of the food crops; therefore, calculation of TFs in the major agricultural products is required all over Bangladesh, especially the foodstuffs produced near the Rooppur Nuclear Power Plant, which is scheduled to be commissioned in 2023.
    Matched MeSH terms: Radiation Monitoring*
  8. Mohd Ridzwan SF, Fritschi L, Bhoo-Pathy N, Lei Hum W
    Health Phys, 2023 Oct 01;125(4):260-272.
    PMID: 37347198 DOI: 10.1097/HP.0000000000001712
    Personal dosimeters are used by medical radiation workers (MRWs) to monitor their radiation dose from external sources and comply with radiation safety guidelines. Nevertheless, there is evidence of inconsistent use of the devices among MRWs. Behavioral factors influencing the use of personal dosimeters have never been explored. Using established behavioral models, we aimed to develop a psychometric tool to measure the behavioral factors influencing dosimeter use and establish its feasibility, reliability, and validity. A 37-item tool was developed based on a qualitative study and review of the literature. The content relevancy was assessed by six field experts before it was piloted and re-tested on MRWs. The construct validity of the tool was analyzed using exploratory factor analysis to confirm its psychometric properties. Face validation was performed by academicians, field experts, and MRWs to enhance the tool's readability. The 37 items in the tool belonged to five constructs in the early phase. However, the validation study revealed a reliable 27 item tool with seven constructs, namely: "Attitude," "Social factors," "Ability to perform if facilitated," "Ability to overcome shortcomings," "Self-efficacy," "Complexity," and "Perceived usefulness." The item-construct validity index of accepted items was >0.83, and Cronbach's alpha for each construct ranged between 0.70 to 0.96, while factor loading for each item was between 0.723 to 0.963. All results were considered "good" and "excellent." The new tool appears to be valid, reliable, and feasible to measure behavioral factors influencing personal dosimeter use among MRWs, which is helpful to facilitate the planning of interventions to improve behaviors in occupational radiation monitoring.
    Matched MeSH terms: Radiation Dosimeters*
  9. Kasmat NK, Mohamad NS, Tajuddin MA, Mahmud MH
    Med J Malaysia, 2024 Mar;79(Suppl 1):215-219.
    PMID: 38555908
    This study is aimed to determine knowledge and practices on radiation protection among radiographers in nuclear medicine department. A cross-sectional survey was conducted among radiographers in nuclear medicine departments in four health institutions in Malaysia. A set of questionnaires was distributed to 17 respondents using convenience sampling. Approximately more than 75% and 44% - 56% of the radiographers have good knowledge of radiation protection and frequent adherence to radiation protection practices, respectively. Levels of education and length of service were statistically correlated with radiation protection knowledge and practices attributes (p < 0.05), respectively. More training is necessary for knowledge and practice improvement.
    Matched MeSH terms: Radiation Protection*
  10. Alsaffar MS, Kabir NA
    Appl Radiat Isot, 2024 Sep;211:111413.
    PMID: 38944898 DOI: 10.1016/j.apradiso.2024.111413
    The plant acts as an important route for the transfer of radionuclides from the soil to animals, leading to the transfer of radiation to human food products such as beef and milk. Therefore, the level of radioactivity in fodder plays a crucial role in deciding whether cattle may be allowed to graze in a certain area. In this study, the activities of 226Ra, 232Th and 40K were measured via gamma-ray spectrometry on different fodder samples, including napier leaves, rice straw, corn stalks, guinea grass, mixed pasture, palm oil leaves and palm kernel collected from Penang, Malaysia. Theoretical calculations were also conducted to estimate the levels of these radionuclides in caw's products (beef and milk), as well as their potential radiological impact on local consumers. On average, the annual effective dose due to ingestion of radionuclides in milk was 11.39 μSv y-1, whereas in beef it was 5.63 μSv y-1. These values are significantly lower than the worldwide average of 290 μSv y-1. Research confirmed that farmers' usage of the aforementioned feeds did not cause any radiation-related health risks.
    Matched MeSH terms: Radiation Monitoring/methods
  11. Yahya N, Ebert MA, Bulsara M, Haworth A, Kearvell R, Foo K, et al.
    Radiat Oncol, 2014;9:282.
    PMID: 25498565 DOI: 10.1186/s13014-014-0282-7
    To assess the impact of incremental modifications of treatment planning and delivery technique, as well as patient anatomical factors, on late gastrointestinal toxicity using data from the TROG 03.04 RADAR prostate radiotherapy trial.
    Matched MeSH terms: Radiation Injuries/prevention & control; Gastrointestinal Tract/radiation effects*
  12. Sahini MH, Hossain I, Wagiran H, Saeed MA, Ali H
    Appl Radiat Isot, 2014 Sep;92:18-21.
    PMID: 24973463 DOI: 10.1016/j.apradiso.2014.05.024
    Characteristics of the thermoluminescence (TL) responses of Yb- and Yb-Tb-doped optical fibers irradiated with 6MV photons are reported. The concentration of Yb in the Yb-doped optical fiber was 0.26mol%; the concentrations of Yb and Tb in the Yb-Tb-doped optical fiber were 0.62 and 0.2mol%, respectively. The TL dose responses are linear in the dose range 0.5-4Gy. The radiation sensitivity of the Yb-Tb material is almost two orders of magnitude higher than the sensitivity of the material doped with Yb alone.
    Matched MeSH terms: Radiation Tolerance
  13. Ibahim MJ, Crosbie JC, Yang Y, Zaitseva M, Stevenson AW, Rogers PA, et al.
    PLoS One, 2014;9(6):e100547.
    PMID: 24945301 DOI: 10.1371/journal.pone.0100547
    High-dose synchrotron microbeam radiation therapy (MRT) has shown the potential to deliver improved outcomes over conventional broadbeam (BB) radiation therapy. To implement synchrotron MRT clinically for cancer treatment, it is necessary to undertake dose equivalence studies to identify MRT doses that give similar outcomes to BB treatments.
    Matched MeSH terms: Cell Survival/radiation effects; Dose-Response Relationship, Radiation; Cell Proliferation/radiation effects
  14. Hashim S, Ibrahim SA, Che Omar SS, Alajerami YS, Saripan MI, Noor NM, et al.
    Appl Radiat Isot, 2014 Aug;90:258-60.
    PMID: 24858954 DOI: 10.1016/j.apradiso.2014.04.016
    Radiation effects of photon irradiation in pure Photonic Crystal Fibres (PCF) and Flat fibres (FF) are still much less investigated in thermoluminescense dosimetry (TLD). We have reported the TL response of PCF and FF subjected to 6 MV photon irradiation. The proposed dosimeter shows good linearity at doses ranging from 1 to 4 Gy. The small size of these detectors points to its use as a dosimeter at megavoltage energies, where better tissue-equivalence and the Bragg-Gray cavity theory prevails.
    Matched MeSH terms: Radiation Dosage*; Silicon Dioxide/radiation effects*
  15. Mahyuddin NM, Russell G
    ScientificWorldJournal, 2014;2014:876435.
    PMID: 24782671 DOI: 10.1155/2014/876435
    Technology scaling relies on reduced nodal capacitances and lower voltages in order to improve performance and power consumption, resulting in significant increase in layout density, thus making these submicron technologies more susceptible to soft errors. Previous analysis indicates a significant improvement in SEU tolerance of the driver when the bias current is injected into the circuit but results in increase of power dissipation. Subsequently, other alternatives are considered. The impact of transistor sizes and temperature on SEU tolerance is tested. Results indicate no significant changes in Q(crit) when the effective transistor length is increased by 10%, but there is an improvement when high temperature and high bias currents are applied. However, this is due to other process parameters that are temperature dependent, which contribute to the sharp increase in Q(crit). It is found that, with temperature, there is no clear factor that can justify the direct impact of temperature on the SEU tolerance. Thus, in order to improve the SEU tolerance, high bias currents are still considered to be the most effective method in improving the SEU sensitivity. However, good trade-off is required for the low-swing driver in order to meet the reliability target with minimal power overhead.
    Matched MeSH terms: Radiation Monitoring/instrumentation; Radiation Monitoring/methods; Radiation Tolerance
  16. Kannan S, Chandrasekaran B, Muthusamy S, Sidhu P, Suresh N
    Gerodontology, 2014 Jun;31(2):149-52.
    PMID: 24797620 DOI: 10.1111/ger.12010
    Burns of the oral mucosa may be caused by thermal, mechanical, chemical, electrical or radiation injury. Clinically, these burns can produce localised or diffuse areas of tissue damage depending on the severity and extent of the insult. Most oral thermal burns produce erosions or ulcers on the palate or tongue.
    Matched MeSH terms: Radiation Injuries
  17. Chowdhury MA, Jahan I, Karim N, Alam MK, Abdur Rahman M, Moniruzzaman M, et al.
    Biomed Res Int, 2014;2014:145159.
    PMID: 24711991 DOI: 10.1155/2014/145159
    In the present study, the residual pesticide levels were determined in eggplants (Solanum melongena) (n = 16), purchased from four different markets in Dhaka, Bangladesh. The carbamate and organophosphorus pesticide residual levels were determined by high performance liquid chromatography (HPLC), and the efficiency of gamma radiation on pesticide removal in three different types of vegetables was also studied. Many (50%) of the samples contained pesticides, and three samples had residual levels above the maximum residue levels determined by the World Health Organisation. Three carbamates (carbaryl, carbofuran, and pirimicarb) and six organophosphates (phenthoate, diazinon, parathion, dimethoate, phosphamidon, and pirimiphos-methyl) were detected in eggplant samples; the highest carbofuran level detected was 1.86 mg/kg, while phenthoate was detected at 0.311 mg/kg. Gamma radiation decreased pesticide levels proportionately with increasing radiation doses. Diazinon, chlorpyrifos, and phosphamidon were reduced by 40-48%, 35-43%, and 30-45%, respectively, when a radiation strength of 0.5 kGy was utilized. However, when the radiation dose was increased to 1.0 kGy, the levels of the pesticides were reduced to 85-90%, 80-91%, and 90-95%, respectively. In summary, our study revealed that pesticide residues are present at high amounts in vegetable samples and that gamma radiation at 1.0 kGy can remove 80-95% of some pesticides.
    Matched MeSH terms: Carbamates/radiation effects*; Organophosphorus Compounds/radiation effects*; Pesticide Residues/radiation effects*
  18. Dabbagh A, Abdullah BJ, Abu Kasim NH, Ramasindarum C
    Int J Hyperthermia, 2014 Feb;30(1):66-74.
    PMID: 24286257 DOI: 10.3109/02656736.2013.854930
    The emergence of thermal modalities has promoted the use of heat-sensitive phantoms for calibration, measurement, and verification purposes. However, development of durable phantoms with high precision ability to represent the temperature distribution remains a challenge. This study aims to introduce a reusable phantom that provides an accurate assessment of the heated region in various thermal modalities.
    Matched MeSH terms: Coloring Agents/radiation effects; Ethylenediamines/radiation effects; Gels/radiation effects
  19. Sabarudin A, Yusof MZ, Mohamad M, Sun Z
    Radiat Prot Dosimetry, 2014 Dec;162(3):316-21.
    PMID: 24255172 DOI: 10.1093/rpd/nct280
    A study on the radiation dose associated with cerebral CT angiography (CTA) and CT perfusion (CTP) was conducted on an anthropomorphic phantom with the aim of estimating the effective dose (E) and entrance skin dose (ESD) in the eyes and thyroid gland during different CTA and CTP protocols. The E was calculated to be 0.61 and 0.28 mSv in CTA with 100 and 80 kV(p), respectively. In contrast, CTP resulted in an estimated E of 2.74 and 2.07 mSv corresponding to 40 and 30 s protocols, respectively. The eyes received a higher ESD than the thyroid gland in all of these protocols. The results of this study indicate that combining both CTA and CTP procedures are not recommended in the stroke evaluation due to high radiation dose. Application of modified techniques in CTA (80 kV(p)) and CTP (30 s) is highly recommended in clinical practice for further radiation dose reduction.
    Matched MeSH terms: Brain/radiation effects; Radiation Dosage; Skin/radiation effects
  20. Jawad MM, Husein A, Azlina A, Alam MK, Hassan R, Shaari R
    J Biomed Opt, 2013 Dec;18(12):128001.
    PMID: 24337495 DOI: 10.1117/1.JBO.18.12.128001
    Bone regeneration is essential in medical treatment, such as in surgical bone healing and orthodontics. The aim of this study is to examine the effect of different powers of 940 nm diode low-level laser treatment (LLLT) on osteoblast cells during their proliferation and differentiation stages. A human fetal osteoblast cell line was cultured and treated with LLLT. The cells were divided into experimental groups according to the power delivered and periods of exposure per day for each laser power. The (3-(4,5-dimethylthiazol-2yl)-2,5 diphenyl tetrazolium bromide) (MTT) assay was used to determine cell proliferation. Both alkaline phosphatase and osteocalcin activity assays were assessed for cell differentiation. All treatment groups showed a significant increase in cell proliferation and differentiation compared to the control group. Regarding the exposure time, the subgroups treated with the LLLT for 6 min showed higher proliferation and differentiation rates for the powers delivered, the 300-mW LLLT group significantly increased the amount of cell proliferation. By contrast, the 100 and 200 mW groups showed significantly greater amounts of cell differentiation. These results suggest that the use of LLLT may play an important role in stimulating osteoblast cells for improved bone formation.
    Matched MeSH terms: Cell Differentiation/radiation effects*; Osteoblasts/radiation effects*; Cell Proliferation/radiation effects*
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