Siti Fairus Abdul Sani

• PhD
• Associate Professor at University of Malaya

We are developing high spatial resolution radiation-sensitive passive and active insulator sensors, the responses respectively reflecting molecular configuration absorptivity and disruptions, and electron trapping, with readout dependent upon evoked light. Present interest in radiation medicine links with an over-arching aim of providing for the ca...

Introduction: High-dose-rate (HDR) ⁶⁰ Co brachytherapy necessitates accurate dose calculations to minimize normal tissue toxicity and late malignancy risks. Conventionally, the American Association of Physicists in Medicine (AAPM) Task Group 43 (TG-43) formalism, utilizing table-based dose superposition, has been employed for dose calculations, ove...

The purpose of this research was to develop and evaluate a nanocomposite material for the treatment of colorectal cancer. The nanocomposite consisted of manganese-doped silver nanoparticles coated with silica (Si–Ag: Mn3O4). The nanocomposite was synthesized by co-precipitating silver and manganese oxide, followed by a silica coating using the Stob...

75 μm thick PTFE tape attracts interest, forming the basis of a potential skin dosimeter capable of utilization in radiotherapeutic external beam applications. The medium is readily available, for instance in the form of ordinary plumber’s tape as used herein, typically of 12 mm width mounted on a spool. A 60Co (mean energy 1.25 MeV) irradiator has...

Use is made of 50 μm high purity graphite foils, investigating the potential of these in evaluation of dose in dermal and epithelial layers, measuring the thermoluminescence yield obtained as a result of irradiation at mammographic energies. In particular the effort supports the ICRU recommendation that skin dose be assessed at a skin depth 0.07 mm...

Silicon rubber has been used as a protective material to shield sensitive organs of patients located near the skin surface during CT scan examinations. However, the quality of the resulting images has not been thoroughly investigated. This study was to evaluate the resulting image quality of a new synthetic thyroid shield based on silicon rubber (S...

Epithelial-mesenchymal transition (EMT) is increasingly explored in cancer progression. Considering that triple negative (TN) breast cancer has the poorest survival among molecular subtypes, we investigated 49 TN, 45 luminal and 25 HER2-enriched female breast carcinomas for EMT expression (using E-cadherin and vimentin immunohistochemistry) against...

Present study concerns the radiological character of Malaysian honey. A total of 18 samples (representative of the various most common types) were obtained from various honey bee farms throughout the country. Using a high-purity germanium γ-ray spectroscopic system, the samples were analysed for the naturally occurring radionuclides 226 Ra, 228 Ra...

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...

Obesity is strongly linked with increased risk and poorer prognosis of endometrial cancer (EC). Cancer-associated fibroblasts (CAFs) are activated fibroblasts that form a large component of the tumor microenvironment and undergo metabolic reprogramming to provide critical metabolites for tumor growth. However, it is still unknown how obesity, chara...

The average lifetime risk of secondary cancer after irradiating glioblastoma radiation therapy to healthy organs shows that the technique of volumetric modulated arc therapy (VMAT) has a smaller risk of developing secondary cancer compared to intensity modulated radiation therapy (IMRT) and three-dimensional radiation therapy (3DCRT). Parameters of...

Amyloidosis is a deleterious condition caused by abnormal amyloid fibril build-up in living tissues. To date, 42 proteins that are linked to amyloid fibrils have been discovered. Amyloid fibril structure variation can affect the severity, progression rate, or clinical symptoms of amyloidosis. Since amyloid fibril build-up is the primary pathologica...

Thermoluminescence (TL) materials have a broad variety of uses in various fields, such as clinical research, individual dosimetry, and environmental dosimetry, amongst others. However, the use of individual neutron dosimetry has been developing more aggressively lately. In this regard, present study establishes a relationship between the neutron do...

Bladder cancer is the fourth most common malignancy in males. It can present across the whole continuum of severity, from mild through well-differentiated disease to extremely malignant tumours with poor survival rates. As with other vital organ malignancies, proper clinical management involves accurate diagnosis and staging. Chemotherapy consistin...

Various thicknesses of 2B grade polymer pencil lead graphite (PPLG) were used in the present study, which focussed on the alteration in crystalline lattice and the structural defect caused by the electron irradiation dosage ranging from 0.5 to 20 Gy delivered by an Elekta HD Linac. The fundamental trap parameters i.e. kinetics order (b), activation...

Using commercially available, 0.3 mm thick rod-shaped, highly uniform 2B and HB grade polymer pencil lead graphite (PPLG), and subjected to a low-level neutron dose range of 2–10 Gy, a comprehensive understanding of radiation-induced effects have been achieved. The thermoluminescence (TL) and photoluminescence (PL) dose dependency, as well as chang...

One of the most widely used methods for diagnosing diseases in human tissue is computed tomography (CT). Clinically, CT scans may require contrast media, such as Iohexol, to enhance images of different tissues and organs. However, these iodinized contrast agents have limitations, such as short blood duration, requirement of high-concentration injec...

The thermoluminescence yield of silica glass doped with Gd2O3 and MgO is investigated as a potential material for neutron dose measurement. The dosimetric materials used herein were prepared via the sol-gel route with concentration of rare earth metal oxides varying from 1 to 10 mol%. Reactor irradiations were made at 750 kW thermal power, producin...

Potato Dextrose Agar (PDA) is a semicrystalline polymer made from amylopectin, agarose, and amylose, used in laboratories for Agar plate culturing for a multitude of fungal strains. The existing pretreatment method for the elimination of pathogenic bacteria, namely steam sterilization, has shown several drawbacks, including high cost, uneven heatin...

The dosimetric characteristics of newly developed gadolinium (Gd) glass dosimeter produced via sol-gel method are reported. Irradiation were made using a 750kW neutron flux thermal power and 1.25 MeV ⁶⁰Co gamma rays with entrance doses from 2 to 10 Gy. Investigation has been done on various Gd dopant concentrations, ranging from 1 to 10 mol%. The G...

Present work explores the use of carbon-based materials as novel material for in-vivo radiation dosimetry during routine screening mammography, in part to reliably predict the average glandular dose (AGD) imparted to the patient. The study herein proposes the use of highly uniform 0.3 mm of 2B and HB grade polymer pencil-lead graphite (PPLG) i.e. a...

This study investigates the use of black carbon charcoal as passive radiation dosimetry, offering low dependence on photon energy and near soft tissue effective atomic number with state-of-the-art techniques. Regression analyses have now been conducted using graphite manufactured commercially in the form of charcoal from three different types: mang...

In case of any natural disasters or technical failures of nuclear facilities, the surrounding media including human beings may receive unexpected radiation exposures. In such a situation, there is no viable way to know how much radiation dose is received by human beings. Realizing that motorized vehicles are parked at fixed but increasing distances...

Small field treatments in radiotherapy have been increasingly developed during the last years due to the potential to produce more conformal dose in the target volume and to enhance the therapeutic ratio. On the other hand, dosimetric task for small field techniques is more challenging because of the production of small dimension high dose areas wi...

Like many other decorative building materials, tiles are one of the most precious ornamental ingredients for making a lucrative building image. It not only offers beauty and luxury but also added value by protecting/monitoring ionizing radiation. In this study, the utmost regular use of seven varieties of tile samples has been considered for retros...

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 seed...

Oil reservoirs around the world are facing issues with the extraction ability of the accessible natural resources in the oil fields. Recent investigations on oil recovery have revealed that nanoparticles (NPs) possess a great potential on some parameters like rheology, interfacial tension (IFT), and rock wettability which help in uplifting the trap...

[This corrects the article DOI: 10.1371/journal.pone.0235053.].

Salt (NaCl) has importance not only in regard to the seasoning and preservation of food but also in greater mass utilisation settings, including the salting of roads in wintery conditions. The assessment of health benefits and risk from the intake of salt is of paramount importance, well appreciated in regard to hypernatremia and hypertension but m...

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 v...

Associated with the marked difference between the mechanism of neutrons interactions relative to that of low linear-energy transfer (LET) radiations, few convenient dosimeters offer well differentiated measurement of neutron doses at useful sensitivity and spatial resolution. Present study has made use of highly uniform 2B and HB grade polymer penc...

Brachytherapy is commonly used in treatment of cervical, prostate, breast and skin cancers, also for oral cancers, typically via the application of sealed radioactive sources that are inserted within or alongside the area to be treated. A particular aim of the various brachytherapy techniques is to accurately transfer to the targeted tumour the lar...

The effect of neutron irradiation is investigated in respect of five different Gd dopant concentrations of silica (SiO2) glass; 1–10 mol% via sol-gel route fabrication. Using Raman spectroscopy and X-ray diffraction (XRD), characterization was made of the defects that give rise to the luminescence signal. The approach allows the Si–O–Si coordinatio...

Characterization has been undertaken of the thermoluminescence (TL) properties of 0.3 mm polymer pencil lead graphite (PPLG). For ⁶⁰Co gamma irradiation doses from 0.5 Gy up to 20 Gy readout data have been taken at different heating rates, from 2 to 15 °C s⁻¹, linear TL responses with radiation dose being found, also with a greater degree of sensit...

Control of neutron multiplication in a nuclear reactor is fundamental in achieving stable reactor power. The present study has sought to determine the impact of gadolinium weight percent (w/o) in respect of the number of fuel rods on the neutronic and safety parameters of (Th, U)O2 fuel in a Westinghouse small modular reactor. The MCNPX 2.7 integra...

In this work, the impact of UV illumination intensity on a self-powered photodiode based on organic NPD:Alq3 composite is comprehensively investigated. Solution-processed spin coating was used to fabricate the active layers followed by electrode deposition to form devices with architecture ITO/PEDOT:PSS/NPD:Alq3/LiF/Al. UV–Vis and PL spectrometers...

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. Focus...

Among the various decorative materials used in Bangladeshi dwellings, the marble/marble stone is one of the most common ones that used largely for enhancing the beauty and/or aristocracy of the dwelling environment. The most commonly used six types of marble stone have been analyzed for retrospective accident dosimetry. With the interest of charact...

The dosimetric capabilities of tissue equivalent rod-shaped polymer pencil lead graphite (PPLG) has been investigated using an Elekta HD Linac, evaluated for electrons from 6 to 15 MeV and doses in the range 0.5 Gy up to 20 Gy. These encompass the major irradiation value ranges used in electron radiation therapy procedures. Parameters concerning th...

Herein, we report a novel self-powered photodiode, which is based on all solution-processed active layer made of bulk heterojunction of TPD:Alq3. The photodiodes can be utilized for the detection of ultraviolet (UV) radiation in a self-powered mode without the need for an external power supply. The optimized photodiode with TPD:Alq3 (1:2) active la...

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 60Co gamma rays, delivering doses from 0 to 200 Gy...

The epithelial-mesenchymal transition (EMT) is a crucial process in cancer progression and metastasis. Study of metabolic changes during the EMT process is important in seeking to understand the biochemical changes associated with cancer progression, not least in scoping for therapeutic strategies aimed at targeting EMT. Due to the potential for hi...

In this work, a broad investigation on the optical parameters of TPD:Alq3 composite thin films is reported. The films are prepared from different solution-processed mixtures and are deposited onto the quartz substrate in order to measure their optical response with UV–Vis–NIR spectrophotometer. Results showed that the non-dispersive refractive inde...

For x- and gamma- irradiations delivering entrance doses from 2- up to 1000 Gy to commercial 1.0 mm thick borosilicate glass microscope slides, study has been made of their thermoluminescence yield. With an effective atomic number of 10.6 (approximating bone equivalence), photon energy dependency is apparent in the low x-ray energy range, with inte...

Thermoluminescence dosimetry most typically concerns the sensing and quantification of ionizing radiation exposures, with evaluation of absorbed dose arising from electron-hole trapping in well-disposed insulating/ semi-conducting media. In this passive form of dosimetry the signal derives from photons released post-irradiation heating of the dosim...

Metallic nanoparticle radiosensitization (MNPR) is attracting a good deal of attention, promising enhanced efficiency target volume radiation therapy without escalation of damage to surrounding normal tissues, also devoid of modification to the irradiation setup. To study the process of DNA damage in MNPR, physical dose in the sub-cellular scale sh...

The optoelectronics and spectroscopic properties of N, N-diphenyl-N, N-bis(3-methylphenyl)-1, 1-biphenyl-4.4 diamine: tris (8-hydroxyquinolinate) aluminum (TPD:Alq3) systems were investigated for the application of ultraviolet (UV) sensors. Solution processed spin coating technique was used to deposit the films on quartz and to fabricate the device...

Cars of a variety of brands are usually parked at a fixed but increasing distance in the periphery of nuclear installations. Herein we focus on the potential use of car windscreens for post-accident dose reconstruction from unplanned nuclear events and natural disasters, also in regard to unexpected events arising during large-scale use of radioact...

Thorium fuel is presently a globally known future nuclear fuel alternative, having good neutronic, physical and chemical properties in addition to its spent nuclear fuel characteristic proliferation resistance. This research focused on the neutronic and safety parameters of thorium-uranium mixed oxide fuel cycle, utilising three fissile enrichment...

Accidents resulting in widespread dispersal of radioactive materials have given rise to a need for materials that are convenient in allowing individual dose assessment. The present study examines natural Dead Sea salt adopted as a model thermoluminescence dosimetry system. Samples were prepared in two different forms, loose-raw and loose-ground, su...

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,...

9B and H grade carbon-based pencil (carbon concentrations approaching 81 and 62 wt respectively %) have been investigated for radiotherapy dosimetry applications, offering low dependence on photon energy and near soft tissue effective atomic number. Comparison has been made with highly oriented pyrolytic graphite (HOPG), a pure and ordered syntheti...

Determination is made of glow curves attributes of Ge-doped silica fibres fabricated from Ge-doped preforms. In particular interest is in Ge-doped cylindrical (Ge-CF) and Ge-doped flat (Ge-FF). The fabrications are irradiated using various ionizing radiation sources types, protons (150 MeV, 210 MeV), 6 and 10 MV photons, 6 MeV electrons, and 60Co g...

Recently much attention has been paid to microbeam and minibeam irradiations, present interest focusing on their use in study of the behaviour of single cells, groups of cells, also their application in spatially fractionated radiotherapy. Synchrotrons are the most common source for microbeam radiotherapy (MRT), albeit limited in access and typical...

As a result of the various evolving needs, thermoluminescence dosimetry is constantly under development, with applications intended in environmental and personal radiation monitoring through to the sensing of radiotherapy and radiation processing doses. In radiotherapy dosimetry challenges include small-field profile evaluation, encompassing the fi...

Breast Stromal tissue is significantly involved in the spread of cancer because of molecular variations. The main component, collagen, has a spatial arrangement allowing the investigation of its structural patterns in tissues by X-ray diffraction (XRD). Since detection and classification of tumor type and stage from the pathological examinations is...

This study investigated the combined effect of boron in light water moderator and gadolinia in fuel on the neutronic properties of (U, Th)O 2 fuel in Westinghouse small modular reactor. The reactivity control of boron and gadolinia, and the potential of gadolinia in increasing thermal conductivity of its mixed fuel pellet motivated this study. Mont...

In the event of a radiological accident or attack, immediate need arises for reliable estimation of dose to the population from an affected environment. This would contribute to proper medical treatment and any need for isolation of affected areas. As such, it is important to improve dosimetry assessment through use of locally available materials,...

Radioisotopes represent major sources of ionizing radiation, not least for use in medical applications, brachytherapy and nuclear medicine included. In this, the nuclear reactor is the main source of β⁻ - γ emitting isotopes, an example product being ¹⁵³Sm used in the treatment of pain arising from bone metastases. Present analysis relates to the p...

Present work concerns polymer pencil-lead graphite (PPLG) and the potential use of these in elucidating irradiation-driven structural alterations. The study provides detailed analysis of radiation-induced structural interaction changes and the associated luminescence that originates from the energy absorption. Thermally stimulated emission from the...

This work explores the use of polymer pencil‑lead graphite (PPLG) as a novel material for passive radiation dosimetry, analysis including state-of-the-art techniques. The versatility of carbon materials in such applications arises in great part from the strong dependence of their physical properties on the ratio of sp2 (graphite-like) to sp3 (diamo...

In thin low-Z media irradiated by photon energies of several tens of keV, the presence of a high-Z additive can result in manifest locally modified secondary electron dose. Present study analyses the photoelectron dose enhancement resulting from nanometre thickness gold (atomic number Z = 78) coated on commercial borosilicate (B2O3) glass microscop...

Radiosensitization using high atomic number nanoparticles (NPs) has been shown to be an effective method to enhance radiotherapy efficiency. The pathways by which NPs cause sensitization, are generally categorized as physical, chemical and biological effects. Specifically in the case of keV photon radiotherapy where the contribution of physical eff...

As a result of the various evolving needs, thermoluminescence dosimetry is constantly under development, with applications intended in environmental and personal radiation monitoring through to the sensing of radiotherapy and radiation processing doses. In radiotherapy dosimetry challenges include small-field profile evaluation, encompassing the fi...

At the supramolecular level, the proliferation of invasive ductal carcinoma through breast tissue is beyond the range of standard histopathology identification. Using synchrotron small angle x-ray scattering (SAXS) techniques, determining nanometer scale structural changes in breast tissue has been demonstrated to allow discrimination between diffe...

Pure and Ag-decorated ZnO nanoparticles (NPs) were synthesized using a two stage of modified sol-gel technique on microsized substrates, namely sand particles in an effort to prevent agglomeration during photocatalytic reactions. It was found that ZnO NPs can be grown efficiently on sand particles with good adhesion due to the presence of nanosized...

Breast cancer is one of the leading cancers in women worldwide. Notwithstanding the clear advances being made in treatment, early diagnosis of the disease can certainly be expected to reduce morbidity and mortality. With increasing evidence of the role of epithelial to mesenchymal transition (EMT) in tumour progression, early detection of this phen...

The performance of gadolinium burnable absorber (GdBA) for reactivity control in UO2 and (U, Th)O2 fuels and its impact on spent fuel characteristics was performed. Five fuel assemblies: one without GdBA fuel rod and four each containing 16, 24, 34 and 44 GdBA fuel rods in both fuels were investigated. Reactivity swing in all the FAs with GdBA rods...

Burnable neutron absorbers are used for efficient reactivity control especially in light and heavy water reactors. Effect of gadolinium burnable absorber (GdBA) on reactivity, actinide and non-actinide content of nuclear waste was investigated. Westinghouse small modular reactor (W-SMR) was studied using MCNPX 2.7 code integrated with CINDER90 for...

Five window glass brands popularly used in Bangladeshi dwellings have been analyzed for retrospective accident dosimetry, being inexpensive, highly effective as a barrier to moisture and naturally transparent at optical wavelengths. In examining their potential for dosimetry, study has been made of the annealing – irradiation - readout steps contri...