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Abdomen and pelvis computed tomography procedure: Effective dose assessment and establishment of a local diagnostic reference level
No full textExposure to ionizing radiation may induce cancer risk to the patients proportional to the radiation absorbed dose and the organ sensitivity. Therefore protection of radiation exposure is essential to minimize the radiation cancer risk and prevent the deterministic effects. The International Atomic Energy Agency (IAEA) encourages member countries to establish national diagnostic reference levels (DRLs) to reduce unjustified radiation exposure. This study establishes a local DRL for computed tomography (CT) abdomen and pelvis procedures. In total, 1444 CT abdomen procedures were carried out during nine months. CT abdomen procedures were carried out at King Faisal Specialist Hospital and research center using six CT machines from different vendors. The mean and range of patients’ weight (kg) are 50 (42–120). The recommended DRLs values in DLP (mGy.cm) and CTDIvol (mGy)were 900 and 15 per CT abdomen and pelvis procedure, respectively. 3% (41 cases) were higher than the national DRL for CT abdomen and pelvis. The proposed DRL values are slightly higher than the European and the American College of Radiologists (ACR) DRL values in DLP. The purpose of DRL in terms of CTDIvol (mGy) is comparable with the international guidelines. Thus reducing the scan length, is recommended ensuring that patients receive a minimal possible radiation dose while maintaining the image quality
Thermoluminescence yield of neutron irradiated Gd:Mg-Doped silica glass
No full textThe 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, producing thermal, epi-thermal and fast neutron fluxes of 5.61 × 1012, 2.51 × 1012, 2.58 × 1012 n/c
Thermoluminescent characterization and defect studies of graphite-rich media under high dose neutron exposure
No full textThermoluminescence (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 dosage and the optical property changes of graphite-rich materials caused by high doses of neutron radiation. This has been done with the intention of developing a novel, graphite-based radiation dosimeter. Herein, the TL yield of commercially graphite-rich materials (i.e. graphite sheet, 2B and HB grade pencils) irradiated by neutron radiation with doses ranging from 250 Gy to 1500 Gy has been investigated. The samples were bombarded with thermal neutrons as well as a negligible amount of gamma rays, from the nuclear reactor TRIGA-II installed at the Bangladesh Atomic Energy Commission. The shape of the glow curves was observed to be independent of the given dosage, with the predominant TL dosimetric peak maintained within the region of 163 °C–168 °C for each sample. By studying the glow curves of the irradiated samples, some of the most well theoretical models and techniques were used to compute the kinetic parameters such as the order of kinetics (b), activation energy (E) or trap depth, frequency factor (s) or escape probability, and trap lifetime (τ). All of the samples were found to have a good linear response over the whole dosage range, with 2B grade of polymer pencil lead graphite (PPLGs) demonstrating a higher level of sensitivity than both HB grade and graphite sheet (GS) samples. Additionally, the level of sensitivity shown by each of them is highest at the lowest dosage that was given, and it decreases as the dose increases. Importantly, the phenomenon of dose-dependent structural modifications and internal annealing of defects has been observed by assessing the area of deconvoluted micro-Raman spectra of graphite-rich materials in high-frequency areas. This trend is consistent with the cyclical pattern reported in the intensity ratio of defect and graphite modes in previously investigated carbon-rich media. Such recurrent occurrences suggest the idea of employing Raman microspectroscopy as a radiation damage study tool for carbonaceous materials. The excellent responses of the key TL properties of the 2B grade pencil demonstrate its usefulness as a passive radiation dosimeter. As a consequence, the findings suggest that graphite-rich materials have the potential to be useful as a low-cost passive radiation dosimeter, with applications in radiotherapy and manufacturing
Awareness level, knowledge and attitude towards breast cancer among staff and students of Hail University, Saudi Arabia
Get PDFIntroduction
Awareness of screening procedures and illness warning signals is critical for expanding and implementing screening programs in society, which would improve the odds of early identification of breast cancer.
Objectives
This study aimed to evaluate the knowledge, awareness, attitudes, and practices related to breast cancer risk factors, signs, symptoms and methods of screening among female faculty and students at Hail University in the Kingdom of Saudi Arabia.
Methods
A cross-sectional study was conducted from January 2021 through February 2021 in the Hail region of Saudi Arabia. A closed-ended questionnaire, which consisted of 37 questions, was distributed online (using a Google Forms link) in both English and Arabic languages. Data was collected from 425 female subjects who participated in the study.
Results
The study showed an overall knowledge level of 46.36% regarding breast cancer. Participants had average knowledge about risk factors, signs, and symptoms, whereas their awareness and practice of breast self-examination and screening methods were weak.
Conclusion
The current study concluded that public awareness of breast cancer remains relatively low, and Saudi Arabia still needs several public awareness initiatives using mass media, such as television, the Internet, and radio, as well as social media. Special awareness programs should also be held in places where a large number of women can easily be reached, such as colleges, universities, and hospitals
Dose mapping in Cesium-137 blood irradiator using novel Ge-doped silica optical fibres in comparison with gafchromic EBT-XD film: A preliminary study
No full textThe purpose of dose-mapping in blood irradiation is to ensure radiation dose delivered to the blood bags is within the specified limits of minimum 15 Gy and maximum 50 Gy, thus preventing any blood transfusion-related diseases. In the present study, we investigated the feasibility of novel fabricated germanium-doped (Ge-doped) silica-based optical fibre as a potential passive dosimeter for dose-mapping of a Cesium-137 (Cs-137) gamma blood irradiator. The calibration curve of optical fibres and Gafchromic EBT-XD film was established by irradiating the samples in the dose range from 5 to 35 Gy at the central of a water-equivalent phantom in a dedicated blood irradiator machine. For dose mapping, the fabricated optical fibres and EBT-XD film were irradiated for a gamma exposure of 8 min and 56 s to deliver a central dose of 25 Gy. Thermoluminescence measurements were performed using a Harshaw 3500 TLD reader at a maximum acquisition temperature of 400 °C. The results of optical fibres were compared with EBT-XD film. The absorbed dose obtained from optical fibres shows deviation of within 0.1%–10.4% compared to that of dose of the film. The fabricated optical fibre studied in this work have a good potential as a new passive dosimeter for characterisation and dose mapping of gamma blood irradiator due to its high sensitivity and reproducible characteristics
Effect of Tm2O3 addition on the physical, structural, elastic, and radiation-resisting attributes of tellurite-based glasses
No full textThe influence of adding Tm2O3 in the tellurite-based glasses is analyzed through their physical, optical, structural, elastic, and gamma rays resisting features. The proposed glasses are prepared via the classic melt-quenching technique. As the Tm2O3 concentration is raised (TeO2 reduced), glass properties like density (ρ), and refractive index (nd) are elevated indicating an enhancement in the glass structure. Elastic constants were analyzed to rise with Tm3+ addition due to the production of bridging oxygens in the system. The elastic constants E, K, and G were perceived to rise with the Tm3+ concentration from 90.4 to 157 GPa, 131−156 GPa, 38.7−42.1 GPa. The μ values reduced from 244.14 t0 0.19 cm−1 (for the TmZT1 sample) and from 298.82 to 0.23 cm−1 (for TmZT5) when the γ-ray energy enriched between 0.015 and 15 MeV. And there is a good agreement between the MC simulated μm values and the theoretically calculated XCOM μm values. The difference (%) between both of the mentioned results is found in the range of ±2%. At γ ray energy of 0.662 MeV, as glass thickness increases, the radiation protection efficiency of each sample increases from 17.5 to 68.6% (for TmZT1), from 33.2 to 70.2% (for TmZT2), from 34.2 to 71.5% (for TmZT3), from 35.3 to 72.9% (for TmZT4), and from 36.4 to 74.3% (for TmZT5)
Two conformational polymorphs of a bioactive pyrazolo[3,4-d]pyrimidine
Get PDFTwo monoclinic (P21/c; Z′ = 1) polymorphs, α (from methanol) and β (from ethanol, n-propanol and iso-propanol), of a bioactive pyrazolo[3,4-d]pyrimidine derivative have been isolated and characterised by X-ray crystallography as well as by a range of computational chemistry techniques. The different conformations observed for the molecules in the crystals are due to the dictates of molecular packing as revealed by geometry-optimisation calculations. The crucial difference in the molecular packing pertains to the formation of phenylamino-N–H···N(pyrazolyl) hydrogen bonding within supramolecular chains with either helical (α-form; 21-screw symmetry) or zigzag (β-form; glide symmetry). As a consequence, the molecular packing is quite distinct in the polymorphs. Lattice energy calculations indicate the β-form is more stable by 11 kJ/mol than the α-form
Need for vape warning label
No full textLETTERS: The lack of adequate labelling on vape liquids, also known as e-liquid or e-juice, has contributed to an increase of acute nicotine poisoning among children
Critical shortfalls in vape liquid traceability
No full textTHE incidence of acute nicotine poisoning among children due to vaping is a stark reflection of a far-reaching issue: the critical lack of much-needed regulation. This distressing concern calls for immediate, comprehensive attention
Carbon rich media for luminescence-based surface dosimetry and study of associated surface defects
No full textThe 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