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  1. Fulltext Vanishing lung syndrome Masquerading as bilateral pneumothorax: A case report
    Muhamad NI, Mohd Nawi SN, Yusoff BM, Ab Halim NA, Mohammad N, Wan Ghazali WS
    Respir Med Case Rep, 2020;31:101276.
    PMID: 33209576 DOI: 10.1016/j.rmcr.2020.101276
    Vanishing lung syndrome (VLS) is a rare condition characterized by giant emphysematous bullae. It is frequently misdiagnosed as pneumothorax. We describe a case of a 30-year-old male who presented with shortness of breath, reduced effort tolerance, and pleuritic chest pain for three months. He was initially diagnosed with bilateral pneumothorax based on clinical examination and chest radiograph findings. However, further imaging with a high resolution computed tomography (HRCT) of the thorax confirmed bilateral giant emphysematous bullae. Our patient subsequently underwent video-assisted thoracoscopic surgery (VATS) and bullectomy. In this report, we discuss the clinical presentations, radiological features, and the management of VLS. We also highlight the differentiating features of VLS from a pneumothorax.
  2. Studies of thermoluminescence kinetic parameters of polymer pencil lead graphite under photon exposures
    Khandaker MU, Mat Nawi SN, Bradley DA, Lam SE, Abdul Sani SF, Sulieman A
    Appl Radiat Isot, 2021 Aug;174:109757.
    PMID: 33990033 DOI: 10.1016/j.apradiso.2021.109757
    This study analysed thermoluminescence (TL) glow curves of the polymer pencil lead graphite (PPLG) due to its potential applications in radiation dosimetry. The TL glow curves provide information on the physical parameters of the defects participating in luminescence process. The glow curves for different diameters PPLG samples were obtained with varying temperature from 50 to 300 °C, at a fixed heating rate of 10 °Cs-1. A number of methods (initial rise, peak shape and curve fitting) were used to fit the TL glow peaks of the PPLG samples obtained under photon dose of 200 Gy. From the fitted TL signals, the trap parameters such as the order of kinetics, the activation energy, the frequency factor, etc. for the individual peaks were numerically determined. The lifetimes of TL process were calculated assuming the first-order kinetics. The results are compared among the different methods adopted in this study. Implications about the possible results in glow curve deconvolution are discussed.
  3. Graphite sheets in study of radiation dosimetry and associated investigations of damage
    Bradley DA, Ee LS, Mat Nawi SN, Abdul Sani SF, Khandaker M, Alzimami K, et al.
    Appl Radiat Isot, 2021 Aug;174:109769.
    PMID: 34048993 DOI: 10.1016/j.apradiso.2021.109769
    Present work builds upon prior investigations concerning the novel use of graphite-rich polymer pencil-lead for passive radiation dosimetry. Working with photon-mediated interactions at levels of dose familiar in radiotherapy, exploratory investigations have now been made using graphite produced commercially in the form of 50 μm thick sheets. Focusing on the relationship between absorbed radiation energy and induced material changes, investigations have been made of thermo- and photoluminescence dose dependence, also of alterations in Raman spectroscopic features. Photoluminescence studies have focused on the degree of structural order of the samples when exposed to incident MeV energy gamma-radiation, supported by crystallite size evaluations. The results are consistent and evident of structural alterations, radiation-driven thermal annealing also being observed. The results, supportive of previous TL, Raman and photoluminescence studies, are readily understood to arise from irradiation changes occurring at the microscopic level. Notwithstanding the non-linearities observed in the conduct of Raman and photoluminescence studies there is clear potential for applications in use of the defect-dependent methods herein, providing sensitive detection of radiation damage in graphite and from it dose determination. Most specifically, the readily available thin graphite sheets can provide the basis of a low-cost yet highly effective system for studies of radiation-driven changes in carbon (and/or carbon based composites), also as a dosimetric probe of skin dose, its atomic number closely matching with the effective atomic number of soft tissues.
  4. Fulltext Older Adults with Hypertension: Prevalence of Falls and Their Associated Factors
    Abu Bakar AA, Abdul Kadir A, Idris NS, Mohd Nawi SN
    Int J Environ Res Public Health, 2021 08 04;18(16).
    PMID: 34444005 DOI: 10.3390/ijerph18168257
    Falls are prominent health issues among older adults. Among hypertensive older adults, falls may have a detrimental effect on their health and wellbeing. The purpose of this study is to determine the prevalence of falls among hypertensive older adults and to identify the associated factors that contribute to their falls. This was a cross-sectional study conducted among two hundred and sixty-nine hypertensive older adults who were selected via systematic random sampling in two primary health clinics in Kuala Terengganu, Malaysia. Data on their socio-demographic details, their history of falls, medication history and clinical characteristics were collected. Balance and gait were assessed using the Performance Oriented Mobility Assessment (POMA). It was found that 32.2% of participants reported falls within a year. Polypharmacy (adjusted OR 2.513, 95% CI 1.339, 4.718) and diuretics (adjusted OR 2.803, 95% CI 1.418, 5.544) were associated with an increased risk of falls. Meanwhile, a higher POMA score (adjusted OR 0.940, 95% CI 0.886, 0.996) and the number of antihypertensives (adjusted OR 0.473, 95% CI 0.319, 0.700) were associated with a low incidence of falling among hypertensive older adults. Falls are common among hypertensive older adults. Older adults who are taking diuretics and have a polypharmacy treatment plan have a higher incidence of falls. However, older adults taking a higher number of anti-hypertensive medications specifically were not associated with an increased prevalence of falls.
  5. Fulltext Raman and photoluminescence spectroscopy analysis of gamma irradiated human hair
    Lam SE, Mat Nawi SN, Abdul Sani SF, Khandaker MU, Bradley DA
    Sci Rep, 2021 04 12;11(1):7939.
    PMID: 33846448 DOI: 10.1038/s41598-021-86942-4
    Preliminary study has been made of black human hair, carbon concentration of some 53%, a model in examining the potential of hair of the human head in retrospective and emergency biodosimetry applications, also offering effective atomic number near to that of water. The hair samples were exposed to [Formula: see text]Co gamma rays, delivering doses from 0 to 200 Gy. Structural alterations were observed, use being made of Raman and photoluminescence (PL) spectroscopy. Most prominent among the features observed in the first-order Raman spectra are the D and G peaks, appearing at 1370 [Formula: see text] and 1589 [Formula: see text] respectively, the intensity ratio [Formula: see text] indicating dose-dependent defects generation and annealing of structural alterations. The wavelengths of the PL absorption and emission peaks are found to be centred at [Formula: see text] nm and [Formula: see text] nm, respectively. The hair samples mean band gap energy ([Formula: see text]) post-irradiation was found to be [Formula: see text] eV, of the order of a semiconductor and approximately two times the [Formula: see text] of other carbon-rich materials reported via the same methodology.
  6. Carbon rich media for luminescence-based surface dosimetry and study of associated surface defects
    Lam SE, Bradley DA, Mat Nawi SN, Khandaker MU, Abdul Sani SF
    Appl Radiat Isot, 2023 Sep;199:110920.
    PMID: 37419002 DOI: 10.1016/j.apradiso.2023.110920
    The present study continues research into the utilisation of carbonaceous media for medical radiation dosimetry, focusing on the effects of surface area-to-volume ratio and carbon content on structural interaction alterations and dosimetric properties in sheet- and bead-type graphitic materials (with the respective carbon content of ∼98 wt% and ∼90 wt%). Using 60Co gamma-rays and doses from 0.5 Gy to 20 Gy, the study has been made of the response of commercially available graphite in the form of 0.1 mm, 0.2 mm, 0.3 mm and 0.5 mm thick sheets, also of activated carbon beads. Confocal Raman and photoluminescence spectroscopy have been employed, examining radiation-induced structural interaction alterations. Dose-dependent variation in the Raman intensity ratio ID/IG relates to the varying dominance of defect generation and dose-driven defect annealing. Of the various thickness graphite sheets, the 0.1 mm thick medium possesses the greatest surface area-to-volume ratio. Perhaps unsurprisingly, it also exhibits the greatest thermoluminescence (TL) yield compared to that of the other carbonaceous sheet foils used herein. Moreover, the second greatest mass-normalised TL yield has been observed to be that of the porous beads, reflected in the greater defect density (ID/IG > 2) when compared to the other media, due in part to their inherent feature of large internal surface area. Considering the challenge posed in matching skin thickness with skin dose, the near tissue equivalent graphite sheets show particular promise as a skin dosimeter, sensitive as a function of depth.
  7. Acrocyanosis as a rare presentation of drug-induced cutaneous vasculitis: a case report
    Zakaria ER, Wan Ghazali WS, Sazali H, Shahril NS, Md Salleh S, Mohd Nawi SN
    BMC Rheumatol, 2024 Sep 10;8(1):41.
    PMID: 39256797 DOI: 10.1186/s41927-024-00413-7
    BACKGROUND: Acrocyanosis is characterised by persistent bluish discolouration of the extremities, resulting from reduced peripheral blood flow leading to increased oxygen extraction. The aetiology can be divided into primary and secondary causes. While primary acrocyanosis is generally painless and has a benign course, secondary causes may lead to complications. This case reported acrocyanosis secondary to cutaneous vasculitis which progressed to digital gangrene, which is a rare complication of cutaneous vasculitis.

    CASE PRESENTATION: A 68-year-old man presented with a four-day history of bluish discolouration involving bilateral toes associated with pain and started to become gangrenous. Investigations for critical limb ischemia did not show evidence of critical arterial stenosis. Further history revealed history of recent administration of intramuscular injections with diclofenac, a non-steroidal anti-inflammatory agent for renal colic pain a few days prior to the onset of the. Thorough skin search showed multiple purpuric rash of his thighs, buttocks and abdomen. Skin biopsy confirmed the diagnosis of cutaneous (lymphocytic) vasculitis, which was likely to be drug-induced. The acrocyanosis initially responded to methylprednisolone, however unfortunately it progressed further to digital gangrene which required bilateral transmetatarsal amputations.

    CONCLUSION: Knowledge on clinical features, aetiology and investigations of secondary acrocyanosis is crucial for early recognition and treatment of the underlying cause to prevent irreversible complications.

  8. Gamma irradiated thermoluminescence response of Ge-doped SiO2 fibre
    Wahib N, Zulkepely NN, Mat Nawi SN, Amin YM, Ling YS, Abdul Sani SF, et al.
    Appl Radiat Isot, 2015 Nov;105:158-162.
    PMID: 26313622 DOI: 10.1016/j.apradiso.2015.08.025
    Over the past decade and more, considerable interest has been shown in the thermoluminescence (TL) properties of silica-based single-mode optical fibres, in particular investigating potential ionising radiation dosimetry applications. Herein, study has been made of TL glow curve, dose response, reproducibility and fading of 6mol% Ge-doped silica, fabricated in-house and produced in the form of cylindrical fibres. Three different pairings of doped-core and silica cladding diameters were produced: (40, 241)µm, (80, 483)µm and (100, 604)µm. The TL results were compared against that of TLD-100, one of the most sensitive commercially available LiF-based TL media. For all three pairings of diameters, closely similar TL glow curve were obtained, formed of a single peaked structure with a maximum TL yield located between the temperatures 250 and 310°C. The TL yield of the fibres were linear over the range of doses investigated, from 1Gy up to 10Gy, their dose response exceeding that of TLD-100, the samples also being found to be reusable, without evidence of degradation.
  9. Fulltext COVID-19 in the elderly: A Malaysian perspective
    Mustaffa N, Lee SY, Mohd Nawi SN, Che Rahim MJ, Chee YC, Muhd Besari A, et al.
    J Glob Health, 2020 Dec;10(2):020370.
    PMID: 33214887 DOI: 10.7189/jogh.10.020370
  10. Radiation induced defects in graphite
    Bradley DA, Ee LS, Mat Nawi SN, Abdul Sani SF, Khandaker M, Alzimami K, et al.
    Appl Radiat Isot, 2022 Feb 10;182:110141.
    PMID: 35180526 DOI: 10.1016/j.apradiso.2022.110141
    We provide retrospective analysis of a consolidated set of confocal Raman microspectrometry and photoluminescence data for irradiated graphitic materials, detecting the generation of low-dose defects. Within the dose range 0.1 Gy-0.2 kGy, one attracting marginal attention in previous radiation damage studies, an effect is seen that potentially seeds material weakening, the pooled data covering independent x-, gamma-rays, and thermal neutron field irradiations. Categorised in terms of a number of key influencing factors, an emergent pattern of response for the various samples under study is observed, indicative of the cycling of radiation driven energy storage and subsequent relaxation. This novel technique, to be referred to herein as defectroscopy, provides a probe of the generation of radiation-induced defects and internal annealing, the strength of the effects being strongly identified to arise from a combination of the ratio of surface area to volume of the samples, fractional carbon content, linear energy transfer, and strain-related defects within the initial material. These examinations offer a first step in considering whether the technique offers wider applicability, not least in early determination of changes in materials with widespread importance in structural and functional roles.
  11. Photonic crystal fibre as a potential medium for radiotherapy dosimetry
    Begum M, Rahman AKMM, Abdul-Rashid HA, Yusoff Z, Mat Nawi SN, Khandaker MU, et al.
    Appl Radiat Isot, 2021 Aug;174:109771.
    PMID: 34048992 DOI: 10.1016/j.apradiso.2021.109771
    Present study concerns the key thermoluminescence (TL) properties of photonic crystal fibres (PCFs), seeking development of alternatively structured TL materials that are able to offer a advantages over existing passive dosimeters. In terms of their internal structure and light guiding properties the PCFs, collapsed and structured, differ significantly from that of conventional optical fibres. To investigate the dosimetric parameters of the PCFs use was made of a linear accelerator producing a 6 MV photon beam, delivering doses ranging from 0.5 Gy to 8 Gy. The parameters studied included TL response, linearity index, glow curves, relative sensitivity and TL signal fading, the results being compared against those obtained using TLD-100 chips. At 4 Gy photon dose the Ge-doped collapsed PCFs were found to provide a response 27 × that of structured PCF, also giving a TL yield similar to that of standard TLD-100 chips. Over post-irradiation periods of 15 and 30 days collapsed PCF TL signal fading were 8% and 17% respectively, with corresponding values of 37% and 64% for the structured PCF. Trapping parameters including the order of kinetics (b), activation energy (E) and frequency factor (s-1) were assessed with Chen's peak shape method. Lifetime of trapping centre was found to be (2.36 E+03) s and (9.03 E +01) s regarding the collapsed and structured PCF respectively with 6 Gy of photon beam. For the Ge-doped collapsed PCF, the high TL yield, sensitivity and low fading provide the basis of a highly promising system of TLD for radiotherapy applications.
  12. Fulltext Tailored Ge-doped fibres for passive electron radiotherapy dosimetry
    Mat Nawi SN, Abdul Sani SF, Khandaker MU, Ung NM, Almugren KS, Alkallas FH, et al.
    PLoS One, 2020;15(7):e0235053.
    PMID: 32673337 DOI: 10.1371/journal.pone.0235053
    Study has been made of the thermoluminescence yield of various novel tailor-made silica fibres, 6 and 8 mol % Ge-doped, with four differing outer dimensions, comprised of flat and cylindrical shapes, subjected to electron irradiation. Main thermoluminescence dosimetric characteristics have been investigated, including the glow curve, dose response, energy dependence, minimum detectable dose, effective atomic number, linearity of index and sensitivity of the fibres. The studies have also established the uncertainties involved as well as the stability of response in terms of fading effect, reproducibility and annealing. In addition, dose-rate dependence was accounted for as this has the potential to be a significant factor in radiotherapy applications. The 6 and 8 mol % fibres have been found to provide highly linear dose response within the range 1 to 4 Gy, the smallest size flat fibre, 6 mol% Ge-doped, showing the greatest response by a factor of 1.1 with respect to the highly popular LiF phosphor-based medium TLD100. All of the fibres also showed excellent reproducibility with a standard deviation of < 2% and < 4% for 6 and 8 mol % Ge-doped fibres respectively. For fading evaluation, the smallest 6 mol% Ge-doped dimension flat fibre, i.e., 85 × 270 μm displayed the lowest signal loss within 120 days post-irradiation, at around 26.9% also showing a response superior to that of all of the other fibres. Moreover, all the fibres and TLD-100 chips showed independence with respect to electron irradiation energy and dose-rate. Compared with the 8 mol% Ge-doped optical fibres, the 6 mol% Ge-doped flat optical fibres have been demonstrated to possess more desirable performance features for passive dosimetry, serving as a suitable alternative to TLD-100 for medical irradiation treatment applications.
  13. Fulltext The Thermoluminescence Response of Ge-Doped Flat Fibers to Gamma Radiation
    Nawi SN, Wahib NF, Zulkepely NN, Amin YB, Min UN, Bradley DA, et al.
    Sensors (Basel), 2015;15(8):20557-69.
    PMID: 26307987 DOI: 10.3390/s150820557
    Study has been undertaken of the thermoluminescence (TL) yield of various tailor-made flat cross-section 6 mol% Ge-doped silica fibers, differing only in respect of external dimensions. Key TL dosimetric characteristics have been investigated, including glow curves, dose response, sensitivity, fading and reproducibility. Using a (60)Co source, the samples were irradiated to doses within the range 1 to 10 Gy. Prior to irradiation, the flat fibers were sectioned into 6 mm lengths, weighed, and annealed at 400 °C for 1 h. TL readout was by means of a Harshaw Model 3500 TLD reader, with TLD-100 chips (LiF:Mg, Ti) used as a reference dosimeter to allow the relative response of the fibers to be evaluated. The fibers have been found to provide highly linear dose response and excellent reproducibility over the range of doses investigated, demonstrating high potential as TL-mode detectors in radiation medicine applications. Mass for mass, the results show the greatest TL yield to be provided by fibers of the smallest cross-section, analysis indicating this to be due to minimal light loss in transport of the TL through the bulk of the silica medium.
  14. Exploring the thermoluminescence characteristics of smartphone screen safety glasses for retrospective dosimetry applications
    Muslima U, Khandaker MU, Lam SE, Mat Nawi SN, Abdul Sani SF, Ung NM, et al.
    Appl Radiat Isot, 2024 Oct;212:111457.
    PMID: 39068692 DOI: 10.1016/j.apradiso.2024.111457
    In clinical settings, standard dosimeters might miss radiation mishaps. Retrospective dosimeters could help to track personnel (such as patients and other staff who don't wear dosimeters) exceeding safe limits and assess long-term exposure trends. This study has investigated key thermoluminescence (TL) dosimetric characteristics, including the glow curve structure, dose-response, energy dependence, sensitivity and fading of various safety glasses that are used as screen protectors of smartphones subjected to photon irradiation. Among the studied glasses, the HD Anti-Peep safety glass for iPhone has been found to exhibit a linear dose-response with a regression coefficient of 99% within the dose range of 2-10 Gy. Moreover, all the safety glasses showed independence with respect to photon energy of 6 MV and 10 MV. The TL glow curves of the samples showed a broad glow peak between 125 °C and 325 °C at 10 Gy. The TL kinetic parameters of the safety glasses were also studied by analyzing the glow curves using the peak shape and initial rise method. The geometric factor (μg) is found to be within the range of 0.43-0.53, which indicates the suitability of applying Chen's general-order formula to calculate the kinetic parameters such as activation energy, frequency factor and trap lifetime. The activation energy (E) and frequency factor (s) are found in the range of 0.31-0.54 eV and 4.55 × 103 to 2.12 × 106 s-1 respectively obtained via the peak shape method. The relatively long trap lifetime and observed thermoluminescence features indicate that the HD Anti-Peep safety glass offers a better option to estimate dose retrospectively to ensure the safety of human health.
  15. Fulltext Preparing Malaysia for Population Aging through the Advanced Memory and Cognitive Service in Hospital Universiti Sains Malaysia
    Ab Razak A, Rahman NA, Zulkifly MFM, Sapiai NA, Phoa PKA, Mohamed Mustafar MF, et al.
    Malays J Med Sci, 2023 Oct;30(5):1-6.
    PMID: 37928788 DOI: 10.21315/mjms2023.30.5.1
    Improving healthcare and living conditions has led to an increase in life expectancies and challenges of population aging in Malaysia. The Advanced Memory and Cognitive Service builds on integrated healthcare among multidisciplinary specialists to provide holistic and patient-centred healthcare. The service treats older adults experiencing neurocognitive impairment as well as young individuals with complex neurocognitive disorders and thoroughly screens asymptomatic individuals at high risk of developing neurocognitive disorders. This early intervention strategy is a preventive effort in the hope of reducing disease burden and improving quality of life to prepare Malaysia for the forthcoming population aging.
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