Displaying publications 41 - 60 of 289 in total

  1. Yusof, Z.Y.M., Nambiar, P.
    Malaysian Dental Journal, 2007;28(1):51-58.
    Quality radiographs of diagnostic value are important in root canal treatment. The dentist who has knowledge and skills in the use of radiographs for diagnostic purposes has a professional responsibility to ensure that the radiographs are obtained with minimum risk of radiation dose to and for the benefit of the patient. This article reviews the effectiveness of radiography techniques required for successful root canal treatment with the patient’s interest in mind. Awareness of effectual radiographic techniques, their constraints and applicable techniques for improvements are discussed. It seeks to reduce potentially harmful ionising radiation dose to patients and optimise the use of X-rays to produce diagnostic radiographs during root canal treatment.
    Matched MeSH terms: X-Rays
  2. Yoga, R., Sivapathasundaram, N., Suresh, C.
    Malays Orthop J, 2009;3(1):72-77.
    We evaluated the efficacy of a cement gun to improve the depth of cement penetration in total knee arthroplasty. Ninety-one consecutive patients from two hospitals were recruited for this study. For Group I cement was applied to the tibial baseplate and the proximal tibia with fingers. Group 2 had similar application of cement to the tibial baseplate but cement was pressurized into the proximal tibia using a cement gun.. The knee was kept extended until the cement hardened. Standard post-operative x-rays were reviewed to assess cement penetration into the proximal tibia. The mean cement penetration was 2.1 mm in Group 1 and 3.1 mm in Group 2 and the difference was statistically significant. The use of the cement gun improves cement penetration into the proximal tibia and facilitates early stability of the implant fixation to the bone.
    Matched MeSH terms: X-Rays
  3. Kahairi, A., Ahmad, R.L., Wan Islah, L., Norra, H.
    Ameloblastoma is a slow growing benign tumour of the jaw and patients usually present late after the tumour achieved considerable size to cause facial disfigurement. Diagnosis mainly from tissue biopsy and characteristic findings on plain X-rays does assist in differentiating between types of ameloblastoma. The challenges in the management of this tumour are to provide complete excision as recurrence may occur in incomplete removal and also to reconstruct the bony defect in order to give reasonable cosmetic and functional outcome to the patient.
    Matched MeSH terms: X-Rays
  4. Norzaiti Mohd Kenali
    This is a novel study of the depth of penetration of bonding agents (BA) by using a
    miniaturised CT-scan, XMT.The Linear Attenuation Coefficient describes the fraction of a beam of
    x-rays or gamma rays that is absorbed or scattered per unit thickness of the absorber. The higher
    the LAC, the more opaque the image is. (Copied from article).
    Matched MeSH terms: X-Rays
  5. Ibrahim N, Baqiah H, Abdullah M
    Sains Malaysiana, 2013;42:961-966.
    High quality indium oxide and iron doped indium oxide nanocrystalline films were prepared by the sol-gel method followed by a spin coating technique. The samples were characterized by an X-ray diffractometer, an atomic force microscopy and a UV-vis spectroscopy. All samples had good crystallinity with a preferred orientation in the (222) direction. The crystallite size increased from 12.1 nm for the pure sample to 16.1 nm for the sample with x=0.35 and then decreased to 12.1 nm for the sample with x=0.45. All samples contained nanometer grain sizes with a smooth surface. All films showed a high transmission of over 91% in the wavelength range of 200-800 nm.
    Matched MeSH terms: X-Rays
  6. Abdul Razak Daud, Azleen Mohd. Zain, Azali Muhamad
    A single wall single image x-ray radiographic technique was adopted to investigate thickness variation of steel specimens caused by uniform corrosion. The ability of the 100 kV-160 kV x-rays to produce a meaningful film density for steel was also investigated. The thickness contour maps of corroded steel plates were found matching with the x-ray film density contour maps of the plates. The results confirm that x-ray radiography can be used to detect the thickness reduction of steel caused by uniform corrosion.
    Bagi mengesan perubahan ketebalan keluli akibat kakisan seragam maka radiografi sinar-x teknik imej tunggal dinding tunggal telah digunakan. Kemampuan sinar-x 100 kV-160 kV menghasilkan ketumpatan filem yang sesuai untuk keluli telah juga dikaji. Peta kontur ketebalan bagi spesimen kepingan keluli yang telah mengalami kakisan seragam didapati sepadan dengan peta kontur ketumpatan filem radiografi sinar-x bagi spesimen tersebut. Kajian ini menunjukkan radiografi sinar-x boleh digunakan bagi mengesan penipisan keluli akibat kakisan seragam.
    Matched MeSH terms: X-Rays
  7. Ibrahim N, Yusrianto E, Ibarahim Z
    Sains Malaysiana, 2012;41:1029-1035.
    In this study TiO2 films have been prepared using two different techniques i.e. sol-gel and electron gun evaporation (e-gun) techniques. The films were annealed at 300, 350 and 400oC in air. The microstructure study using field emission scanning electron microscope and x-ray diffractometer showed nanometer grains size and only the film prepared by sol-gel and annealed at 400oC has anatase phase while others are amorphous. To study the effect of the films (as buffer layer) onto the dielectric bolometer Ba0.6Sr 0.4TiO3 as distance sensor, sensors with the configuration of Al/BST/TiO2/RuO2/SiO2/Si were built. Two different measurements i.e. with and without infrared source were carried out to measure the sensitivity and repeatability of the sensors. The sensors which contained sol-gel TiO2 films gave reading for both type of measurements, indicating that the sensor can act as active and passive sensors. However, the sensors which contained e-gun TiO2 films only gave responses when the IR source was used, indicating that they can only act as passive sensors. The most sensitive sensor was TiO2 film prepared by sol gel and annealed at 350oC. In general sensors which contained TiO2 films prepared by sol gel showed good repeatability.
    Matched MeSH terms: X-Rays
  8. Wan Nasarudin Wan Jalal, Huda Abdullah, Mohd Syafiq Zulfakar, Sahbudin Shaari, Mohammad Thariqul Islam, Badariah Bais
    Sains Malaysiana, 2014;43:833-842.
    CaxZn(1_x)Al204thin films (x = 0.00; 0 .05 ; 0.10; 0.15 and 0.20) were prepared by sol-gel method with the substitution of Zn2+ by Ca" in the framework of ZnAl204. The effect of Ca addition on the structure and morphology of CaZnAl204thin films was investigated by x-ray diffraction (xRD), field-emission scanning electron microscope (FESEM), energy-dispersive x-ray spectroscopy (EDx), ultra-violet visible (uv-Vis) and atomic force microscope (AFM). The xRD patterns showed the characteristic peaks of face-centred cubic (fcc)ZnAl204and CaZnAl204. The addition of Ca increased the crystallite size from 8.9 to 302 nm. The bandgap of CaxZnuld204 thin film was found in the range of 3.40 to 3.84 eV. sEm micrograph shows the morphology of all thin films is sphere-like, with the grain size increased from 33 to 123 nm. The AFM images show the roughness of surface morphology increased. The substitution of Zn2+ by Ca" increased the crystallite size, grain size and surface roughness which evidently increased the density (4.59 to 4.64 glcm3) and dielectric constant (8.48 to 9.54). The composition of CaxZn(1_x)Al204is considered as suitable material for GPS patch antennas.
    Matched MeSH terms: X-Rays
  9. Bradley DA, Siti Rozaila Z, Khandaker MU, Almugren KS, Meevasana W, Abdul Sani SF
    Appl Radiat Isot, 2019 May;147:105-112.
    PMID: 30852298 DOI: 10.1016/j.apradiso.2019.02.016
    We explore the utility of controlled low-doses (0.2-100 Gy) of photon irradiation as initiators of structural alteration in carbon-rich materials. To-date our work on carbon has focused on β-, x- and γ-irradiations and the monitoring of radiotherapeutic doses (from a few Gy up to some tens of Gy) on the basis of the thermoluminescence (TL) signal, also via Raman and X-ray photo-spectroscopy (XPS), providing analysis of the dose dependence of single-walled carbon nanotubes (SWCNT). The work has been extended herein to investigate possibilities for analysis of structural alterations in graphite-rich mixtures, use being made of two grades of graphite-rich pencil lead, 8H and 2B, both being in the form produced for mechanical pencils (propelling or clutch pencils). 2B has the greater graphite content (approaching 98 wt %), 8H being a mixture of C, O, Al and Si (with respective weight percentages 39.2, 38.2, 9.8 and 12.8). Working on media pre-annealed at 400 °C, both have subsequently been irradiated to penetrating photon-mediated doses. Raman spectroscopy analysis has been carried out using a 532 nm laser Raman spectrometer, while for samples irradiated to doses from 1 to 40 Gy, XPS spectra were acquired using Al Kα sources (hv ∼1400 eV); carbon KLL Auger peaks were acquired using 50 eV Pass Energy. At these relatively low doses, alterations in order-disorder are clearly observed, defect generation and internal annealing competing as dominating effects across the dose range.
    Matched MeSH terms: X-Rays
  10. Ahmed O, Yushou Song
    Sains Malaysiana, 2018;47:1883-1890.
    X-ray computed tomography (XCT) became an important instrument for quality assurance in industry products as a
    non-destructive testing tool for inspection, evaluation, analysis and dimensional metrology. Thus, a high-quality image
    is required. Due to the polychromatic nature of X-ray energy in XCT, this leads to errors in attenuation coefficient
    which is generally known as beam hardening artifact. This leads to a distortion or blurring-like cupping and streak in
    the reconstruction images, where a significant decrease in imaging quality is observed. In this paper, recent research
    publications regarding common practical correction methods that were adopted to improve an imaging quality have been
    discussed. It was observed from the discussion and evaluation, that a problem behind beam hardening reduction for the
    multi-materials object, especially in the absence of prior information about X-ray spectrum and material characterizations
    would be a significant research contribution, if the correction could be achieved without the need to perform forward
    projections and multiple reconstructions.
    Matched MeSH terms: X-Rays
  11. Bushra A, Sulieman A, Edam A, Tamam N, Babikir E, Alrihaima N, et al.
    Appl Radiat Isot, 2023 Mar;193:110627.
    PMID: 36584412 DOI: 10.1016/j.apradiso.2022.110627
    Computed tomography is widely used for planar imaging. Previous studies showed that CR systems involve higher patient radiation doses compared to digital systems. Therefore, assessing the patient's dose and CR system performance is necessary to ensure that patients received minimal dose with the highest possible image quality. The study was performed at three medical diagnostic centers in Sudan: Medical Corps Hospital (MCH), Advance Diagnostic Center (ADC), and Advance Medical Center (AMC). The following tools were used in this study: Tape measure, Adhesive tape, 1.5 mm copper filtration (>10 × 10 cm), TO 20 threshold contrast test object, Resolution test object (e.g., Huttner 18), MI geometry test object or lead ruler, Contact mish, Piranha (semiconductor detector), Small lead or copper block (∼5 × 5 cm), and Steel ruler, to do a different type of tests (Dark Noise, Erasure cycle efficiency, Sensitivity Index calibration, Sensitivity Index consistency, Uniformity, Scaling errors, Blurring, Limiting spatial Resolution, Threshold, and Laser beam Function. Entrance surface air kerma (ESAK (mGy) was calculated from patient exposure parameters using DosCal software for three imaging modalities. A total of 199 patients were examined (112 chest X rays, 77 lumbar spine). The mean and standard deviation (sd) for patients ESAK (mGy) were 2.56 ± 0.1 mGy and 1.6 mGy for the Anteroposterior (AP) and lateral projections for the lumbar spine, respectively. The mean and sd for the patient's chest doses were 0.1 ± 0.01 for the chest X-ray procedures. The three medical diagnostic centers' CR system performance was evaluated and found that all of the three centers have good CR system functions. All the centers satisfy all the criteria of acceptable visual tests. CR's image quality and sensitivity were evaluated, and the CR image is good because it has good contrast and resolution. All the CR system available in the medical centers and upgraded from old X-ray systems to new systems, has been found to work well. The patient's doses were comparable for the chest X-ray procedures, while patients' doses from the lumbar spine showed variation up to 2 folds due to the variation in patients' weight and X-ray machine setting. Patients dose optimization is recommended to ensure the patients received a minimal dose while obtaining the diagnostic findings.
    Matched MeSH terms: X-Rays
  12. Dheyab MA, Aziz AA, Rahman AA, Ashour NI, Musa AS, Braim FS, et al.
    Biochim Biophys Acta Gen Subj, 2023 Apr;1867(4):130318.
    PMID: 36740000 DOI: 10.1016/j.bbagen.2023.130318
    BACKGROUND: Gold nanoparticles (Au NPs) are regarded as potential agents that enhance the radiosensitivity of tumor cells for theranostic applications. To elucidate the biological mechanisms of radiation dose enhancement effects of Au NPs as well as DNA damage attributable to the inclusion of Au NPs, Monte Carlo (MC) simulations have been deployed in a number of studies.

    SCOPE OF REVIEW: This review paper concisely collates and reviews the information reported in the simulation research in terms of MC simulation of radiosensitization and dose enhancement effects caused by the inclusion of Au NPs in tumor cells, simulation mechanisms, benefits and limitations.

    MAJOR CONCLUSIONS: In this review, we first explore the recent advances in MC simulation on Au NPs radiosensitization. The MC methods, physical dose enhancement and enhanced chemical and biological effects is discussed, followed by some results regarding the prediction of dose enhancement. We then review Multi-scale MC simulations of Au NP-induced DNA damages for X-ray irradiation. Moreover, we explain and look at Multi-scale MC simulations of Au NP-induced DNA damages for X-ray irradiation.

    GENERAL SIGNIFICANCE: Using advanced chemical module-implemented MC simulations, there is a need to assess the radiation-induced chemical radicals that contribute to the dose-enhancing and biological effects of multiple Au NPs.

    Matched MeSH terms: X-Rays
  13. Yunos MA, Hussain SA, Yusoff HM, Abdullah J
    Appl Radiat Isot, 2014 Sep;91:57-61.
    PMID: 24907683 DOI: 10.1016/j.apradiso.2014.05.015
    Radioactive particle tracking (RPT) has emerged as a promising and versatile technique that can provide rich information about a variety of multiphase flow systems. However, RPT is not an off-the-shelf technique, and thus, users must customize RPT for their applications. This paper presents a simple procedure for preparing radioactive tracer particles created via irradiation with neutrons from the TRIGA Mark II research reactor. The present study focuses on the performance evaluation of encapsulated gold and scandium particles for applications as individual radioactive tracer particles using qualitative and quantitative neutron activation analysis (NAA) and an X-ray microcomputed tomography (X-ray Micro-CT) scanner installed at the Malaysian Nuclear Agency.
    Matched MeSH terms: X-Rays
  14. Ho E
    Biomed Imaging Interv J, 2010 Jul-Sep;6(3):e8.
    PMID: 21611049 DOI: 10.2349/biij.6.3.e8
    When x-rays were first discovered, the harmful effects of radiation had to be manifest in the early users before they were known. Today, radiation protection and safety have been established and the effects of radiation, as well as its risks, are known. Even so, medical radiation, in particular the growth in the use of computed tomography (CT), has resulted in soaring radiation doses received by the population in general. Inappropriate use has resulted in overuse, overdose and, perhaps, overdiagnosis, especially when used in screening. In the quest to control and curb the use of procedures involving radiation, however, we must be careful not to provoke a pandemic of irrational fear of radiation. Overreaction to the overuse and overdose of radiation might deter patients from life-saving procedures.
    Matched MeSH terms: X-Rays
  15. Amran TS, Hashim MR, Al-Obaidi NK, Yazid H, Adnan R
    Nanoscale Res Lett, 2013 Jan 18;8(1):35.
    PMID: 23331761 DOI: 10.1186/1556-276X-8-35
    We present an investigation on a coupled system consists of gold nanoparticles and silicon nanocrystals. Gold nanoparticles (AuNPs) embedded into porous silicon (PSi) were prepared using the electrochemical deposition method. Scanning electron microscope images and energy-dispersive X-ray results indicated that the growth of AuNPs on PSi varies with current density. X-ray diffraction analysis showed the presence of cubic gold phases with crystallite sizes around 40 to 58 nm. Size dependence on the plasmon absorption was studied from nanoparticles with various sizes. Comparison with the reference sample, PSi without AuNP deposition, showed a significant blueshift with decreasing AuNP size which was explained in terms of optical coupling between PSi and AuNPs within the pores featuring localized plasmon resonances.
    Matched MeSH terms: X-Rays
  16. Naz MY, Ismail NI, Sulaiman SA, Shukrullah S
    Sci Rep, 2015;5:16583.
    PMID: 26561231 DOI: 10.1038/srep16583
    This study investigated the dry and aqueous erosion of mild steel using electrochemical and dry sand impact techniques. In dry sand impact experiments, mild steel was eroded with 45 μm and 150 μm sand particles. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and micro-hardness techniques were used to elaborate the surface morphology of the eroded samples. The results revealed significant change in morphology of the eroded samples. In-depth analysis showed that although the metal erosion due to larger particles was significantly higher, the fines also notably damaged the metal surface. The surface damages were appreciably reduced with decrease in impact angle of the accelerated particles. The maximum damages were observed at an impact angle of 90°. The hardness of the samples treated with 45 μm and 150 μm sand remained in the range of 88.34 to 102.31 VHN and 87.7 to 97.55 VHN, respectively. In electrochemical experiments, a triple electrode probe was added into the metal treatment process. The linear polarization resistance (LPR) measurements were performed in slurries having 5% (by weight) of sand particles. LPR of the samples treated with 45 μm and 150 μm sand slurries was calculated about 949 Ω.cm(2) and 809 Ω.cm(2), respectively.
    Matched MeSH terms: X-Rays
  17. Rodrigues A, Olivato PR, Zukerman-Schpector J, Maganhi SH, Reis AK, Tiekink ER
    J Phys Chem A, 2015 Aug 13;119(32):8714-23.
    PMID: 26213179 DOI: 10.1021/acs.jpca.5b04019
    The X-ray single crystal analysis of isomeric ortho, meta, and para bromo-substituted α-methylsulfonyl-α-diethoxyphosphoryl acetophenones showed that this class of compound adopts synclinal (gauche) conformations for both [-P(O)(OEt)2] and [-S(O)2Me] groups, with respect to the carbonyl functional group. The phosphonate, sulfonyl, and carbonyl functional groups are joined through an intramolecular network of attractive interactions, as detected by molecular orbital calculations at the M06-2X/6-31G(d,p) level. These interactions are responsible for the more stable conformations in the gas phase, which also persist in the solid-state structures. The main structural distinction in the title compounds relates to the torsion angle of the aryl group (with respect to the carbonyl group), which gives rise to different interactions in the crystal packing, due to the different positions of the Br atom.
    Matched MeSH terms: X-Rays
  18. Choo YSL, Giamberini M, Antonio J, Waddell PG, Benniston AC
    Org Biomol Chem, 2020 Nov 04;18(42):8735-8745.
    PMID: 33094783 DOI: 10.1039/d0ob01533d
    The reaction of diethyl 2,5-bis(tert-butyl)phenoxy-3,6-dihydroxyterephthalate (1) with tetraethylene glycol di(p-toluenesulfonate) under high-dilution conditions afforded several isolated products. Two products were identified as macrocycles with one being the 1 + 1 crown ether derivative 3 (10% yield), and the second being the 2 + 2 crown ether compound D3 (19% yield). The X-ray structure for 3 was determined with the asymmetric unit observed to comprise half of the molecule. The small crown ether ring of 3 interacts with K+ or H+ ions in MeOH, but binding is weak and the macrocyclic cavity is too small to fully encapsulate the K+ ion. Transesterification of compounds 1, its methylated version 2 and 3 with diols such as ethylene glycol or 1,4-butandiol produced monomers (M1-M3) which were reacted with terephthaloyl chloride. Short oligomers were produced (PolyM1-PolyM3) rather than extensive polymeric materials and all displayed solid state fluorescence. The absorption and fluorescence properties of M1-M2 and their polymers can be related to subtle structural changes. The Stokes shift for M2 of 15 627 cm-1 in DCM is one of the largest observed for a simple organic chromophore in fluid solution.
    Matched MeSH terms: X-Rays
  19. Ying, C.K., W.A. Kamil, Matsufuji, Naruhiro
    Charged particle therapy with carbon ions has advantages over conventional radiotherapy using x-ray beams. The application of charged particle therapy has rapidly increased over the last decades. This is due to its characteristic Bragg peak which has relatively low entrance doses and favourable doses distribution. In this research work, Geant4 based Monte Carlo simulation (MC) method has been used to calculate the radiation transportation and dose distributions in tissue-like media. The main objective of the work was to compare the Geant4 simulated depth dose distributions with experimental measurements and verify the capability of the geant4 simulation toolkit. The carbon ion beams for the therapeutic energy of 350 MeV/u and 400 MeV/u respectively were simulated, with the same settings as the experimental work carried out at the treatment room at Heavy Ion Medical Accelerator (HIMAC), National Institute of Radiological Sciences (NIRS), Chiba, Japan. The simulation results were verified with measurements data. The work was to measure the accuracy and quality of the dose distributions by Geant4 MC methods. The results show that the Bragg peak and spread out Bragg peak (SOBP) distributions in simulation has fairly good agreement with measurements.
    Matched MeSH terms: X-Rays
  20. Mohamed-Yassin MS, Baharudin N, Ramli AS, Hashim H
    Malays Fam Physician, 2019;14(1):47-52.
    PMID: 31289633
    It remains a challenge to diagnose aortic dissection in primary care, as classic clinical features are not always present. This case describes an atypical presentation of aortic dissection, in which the patient walked in with pleuritic central chest pain associated with a fever and elevated C-reactive protein. Classic features of tearing pain, pulse differentials, and a widened mediastinum on chest X-ray were absent. This unusual presentation highlights the need for a heightened level of clinical suspicion for aortic dissection in the absence of classic features. The case is discussed with reference to the literature on the sensitivity and specificity of the classic signs and symptoms of aortic dissection. A combination of the aortic dissection detection risk score (ADD-RS) and D-dimer test is helpful in ruling out this frequently lethal condition.
    Matched MeSH terms: X-Rays
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