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  1. Fulltext On the Use of Optically Stimulated Luminescent Dosimeter for Surface Dose Measurement during Radiotherapy
    Yusof FH, Ung NM, Wong JH, Jong WL, Ath V, Phua VC, et al.
    PLoS One, 2015;10(6):e0128544.
    PMID: 26052690 DOI: 10.1371/journal.pone.0128544
    This study was carried out to investigate the suitability of using the optically stimulated luminescence dosimeter (OSLD) in measuring surface dose during radiotherapy. The water equivalent depth (WED) of the OSLD was first determined by comparing the surface dose measured using the OSLD with the percentage depth dose at the buildup region measured using a Markus ionization chamber. Surface doses were measured on a solid water phantom using the OSLD and compared against the Markus ionization chamber and Gafchromic EBT3 film measurements. The effect of incident beam angles on surface dose was also studied. The OSLD was subsequently used to measure surface dose during tangential breast radiotherapy treatments in a phantom study and in the clinical measurement of 10 patients. Surface dose to the treated breast or chest wall, and on the contralateral breast were measured. The WED of the OSLD was found to be at 0.4 mm. For surface dose measurement on a solid water phantom, the Markus ionization chamber measured 15.95% for 6 MV photon beam and 12.64% for 10 MV photon beam followed by EBT3 film (23.79% and 17.14%) and OSLD (37.77% and 25.38%). Surface dose increased with the increase of the incident beam angle. For phantom and patient breast surface dose measurement, the response of the OSLD was higher than EBT3 film. The in-vivo measurements were also compared with the treatment planning system predicted dose. The OSLD measured higher dose values compared to dose at the surface (Hp(0.0)) by a factor of 2.37 for 6 MV and 2.01 for 10 MV photon beams, respectively. The measurement of absorbed dose at the skin depth of 0.4 mm by the OSLD can still be a useful tool to assess radiation effects on the skin dermis layer. This knowledge can be used to prevent and manage potential acute skin reaction and late skin toxicity from radiotherapy treatments.
    Matched MeSH terms: Dose-Response Relationship, Radiation
  2. Data-Centric Routing for Intra Wireless Body Sensor Networks
    Bangash JI, Khan AW, Abdullah AH
    J Med Syst, 2015 Sep;39(9):91.
    PMID: 26242749 DOI: 10.1007/s10916-015-0268-5
    A significant proportion of the worldwide population is of the elderly people living with chronic diseases that result in high health-care cost. To provide continuous health monitoring with minimal health-care cost, Wireless Body Sensor Networks (WBSNs) has been recently emerged as a promising technology. Depending on nature of sensory data, WBSNs might require a high level of Quality of Service (QoS) both in terms of delay and reliability during data reporting phase. In this paper, we propose a data-centric routing for intra WBSNs that adapts the routing strategy in accordance with the nature of data, temperature rise issue of the implanted bio-medical sensors due to electromagnetic wave absorption, and high and dynamic path loss caused by postural movement of human body and in-body wireless communication. We consider the network models both with and without relay nodes in our simulations. Due to the multi-facet routing strategy, the proposed data-centric routing achieves better performance in terms of delay, reliability, temperature rise, and energy consumption when compared with other state-of-the-art.
    Matched MeSH terms: Electromagnetic Radiation
  3. Estimation of breast radiation dose in a mammographic system
    Lee KH, Kandaiya S
    Appl Radiat Isot, 1996 Mar;47(3):361-3.
    PMID: 8935969
    Matched MeSH terms: Radiation Dosage
  4. Radioactivity associated with amang upgrading plants
    Hu SJ, Koo WK, Tan KL
    Health Phys, 1984 Feb;46(2):452-5.
    PMID: 6693279
    Matched MeSH terms: Radiation Dosage
  5. Statistical prediction of terrestrial gamma radiation dose rate based on geological features and soil types in Kota Tinggi district, Malaysia
    Ramli AT, Rahman AT, Lee MH
    Appl Radiat Isot, 2003 Nov-Dec;59(5-6):393-405.
    PMID: 14622942
    A statistical prediction of terrestrial gamma radiation dose rate has been performed, covering the Kota Tinggi district of Peninsular Malaysia. The prediction has been based on geological features and soil types. The purpose of this study is to provide a methodology to statistically predict the gamma radiation dose rate with minimum surveying in an area. Results of statistical predictions using the hypothesis test were compared with the actual dose rate obtained by measurements.
    Matched MeSH terms: Radiation Dosage
  6. Radiation risk for patients undergoing cardiac computed tomography examinations
    Alkhorayef M, Sulieman A, Alzahrani K, Abuzaid M, Alomair OI, Almuwannis M, et al.
    Appl Radiat Isot, 2021 Feb;168:109520.
    PMID: 33307438 DOI: 10.1016/j.apradiso.2020.109520
    The various technological advancements in computed tomography (CT) have resulted in remarkable growth in the use of CT imaging in clinical practice, not the least of which has been its establishment as the most valuable imaging examination for the assessment of cardiovascular system disorders. The objective of this study was to assess the effective radiation dose and radiation risk for patients during cardiac CT procedures, based on studies from four different hospitals equipped with 128 slice CT equipment. A total of eighty-three patients were investigated in this study with different clinical indications. Effective doses were also calculated using software based on Monte Carlo simulation. The mean patient age (years), weight (kg), and body mass index (BMI (kg/m2)) were 49 ± 11, 82 ± 12, and 31 ± 6, respectively. The results of the study revealed that the tube voltage (kVp) and tube current-exposure time product (mAs) ranged between 100 to 140 and 50 to 840 respectively. The overall average patient dose values for the volume CT dose index [(CTDIvol), in mGy)] and dose length product (DLP) (in mGy·cm) were 34.8 ± 15 (3.7-117.0) and 383.8 ± 354 (46.0-3277.0) respectively. The average effective dose (mSv) was 15.2 ± 8 (1.2-61.8). The radiation dose values showed wide variation between different hospitals and even within the same hospital. The results indicate the need to optimize radiation dose and to establish diagnostic reference levels (DRLs) for patients undergoing coronary computed tomography angiography (CCTA), also to harmonize the imaging protocols to ensure reduced radiation risk.
    Matched MeSH terms: Radiation Dosage
  7. Fulltext Establishment of CTPA Local Diagnostic Reference Levels with Noise Magnitude as a Quality Indicator in a Tertiary Care Hospital
    Harun HH, Abdul Karim MK, Abd Rahman MA, Abdul Razak HR, Che Isa IN, Harun F
    Diagnostics (Basel), 2020 Sep 09;10(9).
    PMID: 32916913 DOI: 10.3390/diagnostics10090680
    This study aimed to establish the local diagnostic reference levels (LDRLs) of computed tomography pulmonary angiography (CTPA) examinations based on body size with regard to noise magnitude as a quality indicator. The records of 127 patients (55 males and 72 females) who had undergone CTPAs using a 128-slice CT scanner were retrieved. The dose information, scanning acquisition parameters, and patient demographics were recorded in standardized forms. The body size of patients was categorized into three groups based on their anteroposterior body length: P1 (14-19 cm), P2 (19-24 cm), and P3 (24-31 cm), and the radiation dose exposure was statistically compared. The image noise was determined quantitatively by measuring the standard deviation of the region of interest (ROI) at five different arteries-the ascending and descending aorta, pulmonary trunk, and the left and right main pulmonary arteries. We observed that the LDRL values were significantly different between body sizes (p < 0.05), and the median values of the CT dose index volume (CTDIvol) for P1, P2, and P3 were 6.13, 8.3, and 21.40 mGy, respectively. It was noted that the noise reference values were 23.78, 24.26, and 23.97 HU for P1, P2, and P3, respectively, which were not significantly different from each other (p > 0.05). The CTDIvol of 9 mGy and dose length product (DLP) of 329 mGy∙cm in this study were lower than those reported by other studies conducted elsewhere. This study successfully established the LDRLs of a local healthcare institution with the inclusion of the noise magnitude, which is comparable with other established references.
    Matched MeSH terms: Radiation Dosage
  8. Pharmacotherapy for chronic hemorrhagic radiation proctitis
    Gul YA, Prasannan S, Jabar FM, Shaker AR, Moissinac K
    World J Surg, 2002 Dec;26(12):1499-502.
    PMID: 12297939 DOI: 10.1007/s00268-002-6529-8
    Endoscopic thermal therapy and formalin are being increasingly recommended for the treatment of chronic hemorrhagic radiation proctitis. It may be too early, however, to discard pharmacologic agents from the management process, especially in medical institutions where specialized equipment is unavailable. We prospectively assessed the effectiveness of medical therapy in 14 consecutive patients with chronic hemorrhagic radiation proctitis from July 1999 to June 2001. All 14 subjects were women (mean age 56 years), 13 of whom had had radiotherapy for cancer of the cervix. The median time to onset of symptoms following irradiation was 16 months. Six patients had a hemoglobin level of < 8 g/dl, and blood transfusion was required in 11 patients. In five patients (36%) initially treated with hydrocortisone enemas prior to referral, this treatment continued; and the remaining nine patients were commenced on sucralfate enemas. Two patients given rectal hydrocortisone continued to bleed and were treated with sucralfate enemas and topical formalin, respectively. Rectal sucralfate suspension effectively procured symptomatic alleviation in all 11 patients. Rectal bleeding recurred in two patients who had been managed exclusively with hydrocortisone and sucralfate enemas, respectively, over a mean follow-up of 6 months. Both patients were managed with topical formalin, which controlled their symptoms. Even though the number of subjects in this study is small, sucralfate enema can be recommended as an effective first-line agent for managing patients with chronic hemorrhagic radiation proctitis. The use of more specialized therapy can therefore be reserved for cases where primary treatment failure occurs with sucralfate therapy.
    Matched MeSH terms: Radiation Dosage; Radiation Injuries/diagnosis; Radiation Injuries/drug therapy*
  9. Effect of gamma irradiation on the physical stability of dppc liposomes
    Liyana Mohd Ali Napia, Faizal Mohamed, Hur Munawar Kabir Mohd, Intan Syakeela Ahmad Bastamam, Shamellia Sharin, Norsyahidah Mohd Hidzir, et al.
    Sains Malaysiana, 2018;47:1235-1240.
    Unilamellar liposomes composed of dipalmitoylphosphatidylcholine (DPPC) were prepared by the reverse-phase
    evaporation method and extrusion through a polycarbonate membrane filter. Liposomes at 0.7 mg/mL lipid concentration
    in deionized water were exposed to gamma irradiation at a dose in the range 0.5 to 25 kGy. Gamma irradiation of
    liposomes resulted in the degradation of DPPC lipids into free fatty acids, lysophosphatidylcholine and 1,2-palmitoylphosphatidic
    acid (DPPA). The effect of gamma irradiation towards the physical stability of liposomes was investigated
    by means of dynamic light scattering (DLS), transmission electron microscopy (TEM) and zeta potential analysis. From
    the DLS analysis, no significant changes were observed in the hydrodynamic size of liposomes. TEM images indicate that
    the liposomes surface became smoother and rounder as higher irradiation doses were applied. Zeta potential analysis
    showed that gamma irradiation of DPPC liposomes at radiation doses as low as 0.5 kGy resulted in a drastic rise in the
    magnitude of the zeta potential. The results also demonstrate that gamma irradiation of liposomes suspension enhanced
    the overall stability of liposomes. Hence, it can be concluded that gamma irradiation on DPPC liposomes may potentially
    produce liposomes with higher stability.
    Matched MeSH terms: Radiation Dosage
  10. Fulltext Pediatric Solid Tumor Care and Multidisciplinary Tumor Boards in Low- and Middle-Income Countries in Southeast Asia
    Othman MY, Blair S, Nah SA, Ariffin H, Assanasen C, Soh SY, et al.
    JCO Glob Oncol, 2020 08;6:1328-1345.
    PMID: 32886560 DOI: 10.1200/GO.20.00284
    PURPOSE: Pediatric solid tumors require coordinated multidisciplinary specialist care. However, expertise and resources to conduct multidisciplinary tumor boards (MDTBs) are lacking in low- and middle-income countries (LMICs). We aimed to profile the landscape of pediatric solid tumor care and practices and perceptions on MDTBs among pediatric solid tumor units (PSTUs) in Southeast Asian LMICs.

    METHODS: Using online surveys, availability of specialty manpower and MDTBs among PSTUs was first determined. From the subset of PSTUs with MDTBs, one pediatric surgeon and one pediatric oncologist from each center were queried using 5-point Likert scale questions adapted from published questionnaires.

    RESULTS: In 37 (80.4%) of 46 identified PSTUs, availability of pediatric-trained specialists was as follows: oncologists, 94.6%; surgeons, 91.9%; radiologists, 54.1%; pathologists, 40.5%; radiation oncologists, 29.7%; nuclear medicine physicians, 13.5%; and nurses, 81.1%. Availability of pediatric-trained surgeons, radiologists, and pathologists was significantly associated with the existence of MDTBs (P = .037, .005, and .022, respectively). Among 43 (89.6%) of 48 respondents from 24 PSTUs with MDTBs, 90.5% of oncologists reported > 50% oncology-dedicated workload versus 22.7% of surgeons. Views on benefits and barriers did not significantly differ between oncologists and surgeons. The majority agreed that MDTBs helped to improve accuracy of treatment recommendations and team competence. Complex cases, insufficient radiology and pathology preparation, and need for supplementary investigations were the top barriers.

    CONCLUSION: This first known profile of pediatric solid tumor care in Southeast Asia found that availability of pediatric-trained subspecialists was a significant prerequisite for pediatric MDTBs in this region. Most PSTUs lacked pediatric-trained pathologists and radiologists. Correspondingly, gaps in radiographic and pathologic diagnoses were the most common limitations for MDTBs. Greater emphasis on holistic multidisciplinary subspecialty development is needed to advance pediatric solid tumor care in Southeast Asia.

    Matched MeSH terms: Radiation Oncologists
  11. Prognostic factors and nomogram for survival prediction in patients with primary pulmonary lymphoma: a SEER population-based study
    Low SK, Zayan AH, Istanbuly O, Nguyen Tran MD, Ebied A, Mohamed Tawfik G, et al.
    Leuk Lymphoma, 2019 12;60(14):3406-3416.
    PMID: 31322026 DOI: 10.1080/10428194.2019.1633636
    Primary pulmonary lymphomas (PPLs) are rare lymphoproliferative malignancies arising from the lungs. The prognostic factors and optimal management of PPL have not been clearly defined due to its rarity. This study sought to characterize the significant prognostic factors and develop a validated nomogram for individualized prediction of survival outcomes in patients with PPL. A total of 2325 patients diagnosed with PPL between 1983 and 2010 were identified using the Surveillance, Epidemiology, and End Results (SEER) database. Older age at diagnosis, males, Hispanic race, non-marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue histology, Ann Arbor stage IV were significantly associated with worse OS on multivariable analysis. All treatment modalities, including chemotherapy, surgery, and radiotherapy were independent predictors of survival on univariable analysis. The nomogram built demonstrated good discriminative ability and calibration, with the C-index of 0.690 and 0.730 in the training and validation cohorts, respectively.
    Matched MeSH terms: Radiation Oncology
  12. Fulltext A Single Centre Annual Audit on Computed Tomography Pulmonary Angiogram: Demographic, Clinical Scoring System, Patients’ Outcome
    Low Qin Jian, Teo Kuo Zhau, Mohd Nadzri Misni, Cheo Seng Wee
    Borneo Journal of Medical Sciences, 2020;14(2):11-18.
    MyJurnal
    Computed tomography pulmonary angiogram (CTPA) is widely used in the investigation of suspected pulmonary embolism. CTPA is not without adverse effects as it involves intravenous contrast injection and radiation exposure. The annual incidence of pulmonary embolism is 60 – 70 per 100,000 populations and CTPA remains the commonest imaging modality1. This study aims to audit all CTPA performed at Hospital Sultanah Nora Ismail, Batu Pahat, Johor for the entire year of 2018 to illustrate the demographic data, symptoms, risk factors, clinical scoring system applied and patients’ outcome. A retrospective study was conducted to audit all CTPA performed between 1st January to 31st December 2018 via the radiology department electronic records and patients’ records. There were a total of 60 CTPA performed in the entire year of 2018 with 16 positive and 44 negative scans. Among the 16 positive scans, 7 (44%) had a Wells score above 6, 6 (38%) had a Wells score between 2 – 6 and 3 (18%) had a Wells score less than 2. Out of the 16 positive scans, 4 (25%) were known malignancy and 1 was a known case of anti-phospholipid syndrome. All 60 patients had electrographs and arterial blood gases performed prior to CTPA. D dimer was performed in 15 cases (5%). Among the 16 positive scan patients, 4 (25%) passed away during the same admission directly or indirectly related to pulmonary embolism. This annual computed tomography audit report will assist clinicians in making better diagnostic decision when dealing with patients with suspected pulmonary embolism.
    Matched MeSH terms: Radiation
  13. Fulltext Repeat rate analysis of lower limb radiograph for digital radiography in general radiography at Pantai Klang hospital Selangor
    Nur Aishah Jusnaidi, Nurul Fadhlina Ismail
    Malaysian Journal of Applied Sciences, 2020;5(2):112-116.
    MyJurnal
    Assessing the repeat rate is crucial to reduce unnecessary dose to the patient by identifying the major cause for repeating the x-rays exposure to the patient and apply corrective measures. To analyse the repeat rate of routine lower limb projections in direct digital radiography (DR) from general radiology department of Pantai Klang Hospital. 26 months retrospective repeated radiograph was acquired from Picture Archiving and Communication System (PACS) at Hospital Pantai Klang. The retrieved radiographs were grouped based on the reason for the i radiographs being rejected which are incorrect positioning, incorrect collimation, patient movement, incorrect exposure factors, artefact, and other reasons. Total repeated radiographs retrieved for basic lower limbs projections were 13616. Knee was the highest repeted examination and the lowest repeat rate was tibia fibula. (repeat rate: knee = 1.04%, tibia fibula = 0.57%). incorrect positioning is the major causes for repeat exposure for all examinations type, followed by incorrect collimation, other categories, centring ray error, incorrect exposure factors and artifact.
    Matched MeSH terms: Radiation Exposure
  14. Fulltext Tailoring bismuth borate glasses by incorporating PbO/GeO2 for protection against nuclear radiation
    Kumar A, Jain A, Sayyed MI, Laariedh F, Mahmoud KA, Nebhen J, et al.
    Sci Rep, 2021 Apr 08;11(1):7784.
    PMID: 33833308 DOI: 10.1038/s41598-021-87256-1
    Nuclear radiation shielding capabilities for a glass series 20Bi2O3 - xPbO - (80 - 2x)B2O3 - xGeO2 (where x = 5, 10, 20, and 30 mol%) have been investigated using the Phy-X/PSD software and Monte Carlo N-Particle transport code. The mass attenuation coefficients (μm) of selected samples have been estimated through XCOM dependent Phy-X/PSD program and MCNP-5 code in the photon-energy range 0.015-15 MeV. So obtained μm values are used to calculate other γ-ray shielding parameters such as half-value layer (HVL), mean-free-path (MFP), etc. The calculated μm values were found to be 71.20 cm2/g, 76.03 cm2/g, 84.24 cm2/g, and 90.94 cm2/g for four glasses S1 to S4, respectively. The effective atomic number (Zeff)values vary between 69.87 and 17.11 for S1 or 75.66 and 29.11 for S4 over 0.05-15 MeV of photon-energy. Sample S4, which has a larger PbO/GeO2 of 30 mol% in the bismuth-borate glass, possesses the lowest MFP and HVL, providing higher radiation protection efficiency compared to all other combinations. It shows outperformance while compared the calculated parameters (HVL and MFP) with the commercial shielding glasses, different alloys, polymers, standard shielding concretes, and ceramics. Geometric Progression (G-P) was applied for evaluating the energy absorption and exposure buildup factors at energies 0.015-15 MeV with penetration depths up to 40 mfp. The buildup factors showed dependence on the MFP and photon-energy as well. The studied samples' neutron shielding behavior was also evaluated by calculating the fast neutron removal cross-section (ΣR), i.e. found to be 0.139 cm-1 for S1, 0.133 cm-1 for S2, 0.128 cm-1 for S3, and 0.12 cm-1 for S4. The results reveal a great potential for using a glass composite sample S4 in radiation protection applications.
    Matched MeSH terms: Radiation Protection
  15. Fulltext Noise exposure and hearing symptoms among laundry workers and mechanical cutters in a teaching hospital
    Asaritaminaziah binti Hisam, Siti Marwanis binti Anua
    Journal of Occupational Safety and Health, 2018;15(1):35-41.
    MyJurnal
    Workers who are exposed to high noise level were at risk of noise-induced hearing loss (NIHL). This crosssectional study was conducted to investigate the noise exposure level and hearing symptoms among workers exposed to noise in a teaching hospital. Utilising convenience sampling method, 20 laundry workers and 17 mechanical cutters were recruited into this study. Noise exposure levels were measured using noise dosimeter for 8 hours and information on hearing symptoms were gathered using a modified questionnaire adopted from the American Speech Language Hearing Association (ASHA). A significantly higher mean noise level (85±2 dB(A)) was reported among mechanical cutters as compared to laundry workers (80±3 dB(A)), p=0.001 although the former had shorter duration of noise exposure (20±3 hours per week vs. 28±12 hours per week). Fourteen (70%) laundry workers and six (35%) mechanical cutters had reported having hearing problem in noisy background. Higher proportion of laundry workers (n=8, 57%) had reported hearing symptoms compared to mechanical cutters (n=6, 43%) and longer work years was found to be significantly associated with hearing symptoms (p=0.049). There is a need of appropriate education and training on noise exposure, NIHL and hearing protection devices usage in the workplaces
    Matched MeSH terms: Radiation Dosimeters
  16. Fulltext Bystander Effect Induced in Breast Cancer (MCF-7) and Human Osteoblast Cell Lines (hFOB 1.19) with HDR-Brachytherapy
    Zainudin Nh M, R A, W N R
    J Biomed Phys Eng, 2020 Jun;10(3):319-328.
    PMID: 32637376 DOI: 10.31661/jbpe.v0i0.1135
    Background: Radiation induced bystander effects (RIBEs) occurs in unirradiated cells exhibiting indirect biological effect as a consequence of signals from other irradiated cells in the population.

    Objective: In this study, bystander effects in MCF-7 breast cancer cells and hFOB 1.19 normal osteoblast cells irradiated with gamma emitting HDR Brachytherapy Ir-192 source were investigated.

    Material and Methods: In this in-vitro study, bystander effect stimulation was conducted using medium transfer technique of irradiated cells to the non-irradiated bystander cells. Cell viability, reactive oxygen species (ROS) generation and colony forming assay was employed to evaluate the effect.

    Results: Results indicate that the exposure to the medium irradiated MCF-7 induced significant bystander killing and decreased the survival fraction of bystander MCF-7 and hFOB from 1.19 to 81.70 % and 65.44 %, respectively. A significant decrease in survival fraction was observed for hFOB 1.19 bystander cells (p < 0.05). We found that the rate of hFOB 1.19 cell growth significantly decreases to 85.5% when added with media from irradiated cells. The ROS levels of bystander cells for both cell lines were observed to have an increase even after 4 h of treatment. Our results suggest the presence of bystander effects in unirradiated cells exposed to the irradiated medium.

    Conclusion: These data provide evidence that irradiated MCF-7 breast cancer cells can induce bystander death in unirradiated MCF-7 and hFOB 1.19 bystander cells. Increase in cell death could also be mediated by the ROS generation during the irradiation with HDR brachytherapy.

    Matched MeSH terms: Radiation Injuries
  17. Fulltext The relationship between life-time noise exposure and experience of tinnitus among young adults in the International Islamic University (IIUM) Kuantan
    Zirwatu Hanani, Wan Ahmad Wan Aslynn, Marina L. Alisaputri
    International Journal of Allied Health Sciences, 2019;3(4):914-922.
    MyJurnal
    Introduction: Clinical studies have shown that people suffering from tinnitus are at a high risk of developing serious psychological disturbances or serious psychological distress (Erlandsson &
    Widen, 2004 in Hiller and Goebel, 1998). Thus the purpose of this study was to determine the
    relationship between life-time noise exposure and tinnitus experience among young adults in IIUM Kuantan. Methods: A cross sectional study was used to determine whether there is any association between tinnitus experiences and life-time noise exposure among 11 young adults in IIUM Kuantan from age of 18 to 35 years old who are exposed to the noise. Hearing assessment was done using otoscopy, tympanometry and pure tone audiometry. Participants were asked to fill in a questionnaire on tinnitus experience, and were fitted with a noise dosimeter that measured their noise exposure during waking hours. Values collected from dosimeter were then converted into cumulative life-time noise exposure which refers to the equivalent noise exposure per year (Jokitulppo, Tolvenen & Bjork, 2005). Results: Average cumulative life-time noise exposure of the participants is 72.54 dBA ± 6.9459. Fifty five percent (55%) reported of sometimes having tinnitus. No correlation was found between cumulative life-time noise exposure and tinnitus experience. Conclusion: The cumulative life-time noise exposure among young adults in IIUM Kuantan was found to be lower than the level considered as hazardous. Despite reports of tinnitus experience, there was no evidence that the tinnitus was due to noise exposure.
    Matched MeSH terms: Radiation Dosimeters
  18. Fulltext Transparent Blend of Poly(Methylmethacrylate)/Cellulose Acetate Butyrate for the Protection from Ultraviolet
    Mahmood Raouf R, Abdul Wahab Z, Azowa Ibrahim N, Abidin Talib Z, Chieng BW
    Polymers (Basel), 2016 Apr 14;8(4).
    PMID: 30979233 DOI: 10.3390/polym8040128
    The use of transparent polymers as an alternative to glass has become widespread. However, the direct exposure of these materials to climatic conditions of sunlight and heat decrease the lifetime cost of these products. The aim of this study was to minimize the harm caused by ultraviolet (UV) radiation exposure to transparent poly(methylmethacrylate) (PMMA), which usually leads to changes in the physical and chemical properties of these materials and reduced performance. This was achieved using environmentally friendly cellulose acetate butyrate (CAB). The optical, morphological, and thermal properties of CAB blended with transparent PMMA was studied using UV-VIS spectrophotometry, scanning electron microscopy, X-ray diffraction, dynamic mechanical analysis, and thermal gravimetric analysis. The results show that CAB was able to reduce the effects of UV radiation by making PMMA more transparent to UV light, thereby preventing the negative effects of trapped radiation within the compositional structure, while maintaining the amorphous structure of the blend. The results also show that CAB blended with PMMA led to some properties commensurate with the requirements of research in terms of a slight increase in the value of the modulus and the glass transition temperature for the PMMA/CAB blend.
    Matched MeSH terms: Radiation Exposure
  19. Fulltext Quantitative assessment on coronary computed tomography angiography (CCTA) image quality: comparisons between genders and different tube voltage settings
    Chian TC, Nassir NM, Ibrahim MI, Yusof AK, Sabarudin A
    Quant Imaging Med Surg, 2017 Feb;7(1):48-58.
    PMID: 28275559 DOI: 10.21037/qims.2017.02.02
    BACKGROUND: This study was carried out to quantify and compare the quantitative image quality of coronary computed tomography angiography (CCTA) between genders as well as between different tube voltages scan protocols.

    METHODS: Fifty-five cases of CCTA were collected retrospectively and all images including reformatted axial images at systolic and diastolic phases as well as images with curved multi planar reformation (cMPR) were obtained. Quantitative image quality including signal intensity, image noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of right coronary artery (RCA), left anterior descending artery (LAD), left circumflex artery (LCx) and left main artery (LM) were quantified using Analyze 12.0 software.

    RESULTS: Six hundred and fifty-seven coronary arteries were evaluated. There were no significant differences in any quantitative image quality parameters between genders. 100 kilovoltage peak (kVp) scanning protocol produced images with significantly higher signal intensity compared to 120 kVp scanning protocol (P<0.001) in all coronary arteries in all types of images. Higher SNR was also observed in 100 kVp scan protocol in all coronary arteries except in LCx where 120 kVp showed better SNR than 100 kVp.

    CONCLUSIONS: There were no significant differences in image quality of CCTA between genders and different tube voltages. Lower tube voltage (100 kVp) scanning protocol is recommended in clinical practice to reduce the radiation dose to patient.

    Matched MeSH terms: Radiation Dosage
  20. Characterization and biocompatibility evaluation of bacterial cellulose-based wound dressing hydrogel: effect of electron beam irradiation doses and concentration of acrylic acid
    Mohamad N, Buang F, Mat Lazim A, Ahmad N, Martin C, Mohd Amin MCI
    J Biomed Mater Res B Appl Biomater, 2017 Nov;105(8):2553-2564.
    PMID: 27690276 DOI: 10.1002/jbm.b.33776
    The use of bacterial cellulose (BC)-based hydrogel has been gaining attention owing to its biocompatibility and biodegradability. This study was designed to investigate the effect of radiation doses and acrylic acid (AA) composition on in vitro and in vivo biocompatibility of BC/AA as wound dressing materials. Physical properties of the hydrogel, that is, thickness, adhesiveness, rate of water vapor transmission, and swelling were measured. Moreover, the effect of these parameters on skin irritation and sensitization, blood compatibility, and cytotoxicity was studied. Increased AA content and irradiation doses increased the thickness, crosslinking density, and improved the mechanical properties of the hydrogel, but reduced its adhesiveness. The swelling capacity of the hydrogel increased significantly with a decrease in the AA composition in simulated wound fluid. The water vapor permeability of polymeric hydrogels was in the range of 2035-2666 [g/(m-2  day-1 )]. Dermal irritation and sensitization test demonstrated that the hydrogel was nonirritant and nonallergic. The BC/AA hydrogel was found to be nontoxic to primary human dermal fibroblast skin cells with viability >88% and was found to be biocompatible with blood with a low hemolytic index (0.80-1.30%). Collectively, these results indicate that these hydrogels have the potential to be used as wound dressings. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2553-2564, 2017.
    Matched MeSH terms: Dose-Response Relationship, Radiation
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