HIGHLIGHTS: • Intrabeam x-ray source and spherical applicators were simulated and skin dose was calculated. • Skin dose for constant skin to applicator distance strongly depends on applicator size. • Use of larger applicators generally results in higher skin dose. • The recommended 0.5-1 cm skin to applicator distance does not guarantee skin safety.
MATERIALS AND METHODS: The elemental composition of tungsten carbide was analysed using Field-Emission Scanning Electron Microscopy (FESEM) with energy dispersive X-ray (EDX). The purity of tungsten carbide was 99.9%, APS: 40-50 µm. Three discs of tungsten carbide was fabricated with thickness of 0.1 cm, 0.5 cm and 1.0 cm. Three lead discs with similar thickness were used to compare the attenuation properties with tungsten carbide discs. Energy calibration of gamma spectroscopy was performed by using 123I, 133Ba, 152Eu, and 137Cs. Gamma radiation from these sources were irradiated on both materials at energies ranging from 0.160 MeV to 0.779 MeV. The experimental attenuation coefficients of lead and tungsten carbide were compared with theoretical attenuation coefficients of both materials from NIST database. The half value layer and mean free path of both materials were also evaluated in this study.
RESULTS: This study found that the peaks obtained from gamma spectroscopy have linear relationship with all energies used in this study. The relative differences between the measured and theoretical mass attenuation coefficients are within 0.19-5.11% for both materials. Tungsten carbide has low half value layer and mean free path compared to lead for all thickness at different energies.
CONCLUSION: This study shows that tungsten carbide has high potential to replace lead as new lead-free radiation shielding material in nuclear medicine.
METHODS: Negatively charged acrylic microspheres were labeled with 152Sm ions through electrostatic interactions. In another formulation, the Sm-labeled microsphere was treated with sodium carbonate solution to form the insoluble 152Sm carbonate (152SmC) salt within the porous structures of the microspheres. Both formulations were neutron-activated in a research reactor. Physicochemical characterization, gamma spectrometry, and radiolabel stability tests were carried out to study the performance and stability of the microspheres.
RESULTS: The Sm- and SmC-labeled microspheres remained spherical and smooth, with a mean size of 35 µm before and after neutron activation. Fourier transform infrared (FTIR) spectroscopy indicated that the functional groups of the microspheres remained unaffected after neutron activation. The 153Sm- and 153SmC-labeled microspheres achieved activity of 2.53 ± 0.08 and 2.40 ± 0.13 GBq·g-1, respectively, immediate after 6 h neutron activation in the neutron flux of 2.0 × 1012 n·cm-2·s-1. Energy-dispersive X-ray (EDX) and gamma spectrometry showed that no elemental and radioactive impurities were present in the microspheres after neutron activation. The retention efficiency of 153Sm in the 153SmC-labeled microspheres was excellent (~99% in distilled water and saline; ~97% in human blood plasma), which was higher than the 153Sm-labeled microspheres (~95% and ~85%, respectively).
CONCLUSION: 153SmC-labeled microspheres have demonstrated excellent properties for potential application as theranostic agents for hepatic radioembolization.
Methods: We applied a literature survey methodology to retrieved data from academic databases and subsequently employed a bibliometric technique to analyze the accessed records. Besides, the concise summary, sources of COVID-19 datasets, taxonomy, synthesis and analysis are presented in this study. It was found that the Convolutional Neural Network (CNN) is mainly utilized in developing COVID-19 diagnosis and prognosis tools, mostly from chest X-ray and chest CT scan images. Similarly, in this study, we performed a bibliometric analysis of machine learning-based COVID-19 related publications in the Scopus and Web of Science citation indexes. Finally, we propose a new perspective for solving the challenges identified as direction for future research. We believe the survey with bibliometric analysis can help researchers easily detect areas that require further development and identify potential collaborators.
Results: The findings of the analysis presented in this article reveal that machine learning-based COVID-19 diagnose tools received the most considerable attention from researchers. Specifically, the analyses of results show that energy and resources are more dispenses towards COVID-19 automated diagnose tools while COVID-19 drugs and vaccine development remains grossly underexploited. Besides, the machine learning-based algorithm that is predominantly utilized by researchers in developing the diagnostic tool is CNN mainly from X-rays and CT scan images.
Conclusions: The challenges hindering practical work on the application of machine learning-based technologies to fight COVID-19 and new perspective to solve the identified problems are presented in this article. Furthermore, we believed that the presented survey with bibliometric analysis could make it easier for researchers to identify areas that need further development and possibly identify potential collaborators at author, country and institutional level, with the overall aim of furthering research in the focused area of machine learning application to disease control.
CASE PRESENTATION: A 76-year old male patient, presented to the department with a chief complaint of sensitivity in his upper right back tooth due to attrition. After assessing the pulp status, root canal therapy was planned for the tooth. During the procedure, it was noticed that the dental bur slipped out of the hand piece and the patient had accidentally ingested it. The patient was conscious and had no trouble while breathing at the time of ingestion of the bur although he had mild cough which lasted for a short duration. The dental procedure was aborted immediately and the patient was taken to the hospital for emergency care. The presence and location of the dental bur was confirmed using chest and abdominal x-rays and it was subsequently retrieved by esophagogastroduodenoscopy (EGD) procedure under general anaesthesia on the same day as a part of the emergency procedure. The analysis of this case reaffirms the importance of the use of physical barriers such as rubber dams and gauze screens as precautionary measures to prevent such incidents from occurring.
CONCLUSION: Ingestion of instruments are uncertain and hazardous complications to encounter during a dental procedure. The need for physical barrier like rubber dam is mandatory for all dental procedures. However, the dentist should be well trained to handle such medical emergencies and reassure the patient by taking them into confidence. Each incident encountered should be thoroughly documented to supply adequate guidance for treatment aspects. This would fulfil the professional responsibilities of the dentist/ clinician and may help avoid possible legal and ethical issues. This case report emphasizes on the need for the usage of physical barriers during dental procedures in order to avoid medical emergencies.
CASE PRESENTATION: However, here we report a case of DNPE with a slightly different presentation where there is no preceding trauma and has symptoms that mimic severe pneumonia. He presented with high fever, dyspnoea and pleuritic chest pain. Despite on 10 L of oxygen supplementation via high flow mask and already given bolus intravenous antibiotic, the patient still tachypnoeic and was persistently in type I respiratory failure. His chest X-ray showed consolidative changes. Upon further investigation revealed no evidence of DVT on Doppler ultrasound and normal D-dimer level. Due to the high index of suspicion by the attending physician, PE was suspected and later confirmed with computed tomography pulmonary angiography scan. He was successfully treated with anticoagulation therapy. The objective of this case report is to share the difficult experience of diagnosing PE when the presentation highly atypical and mimics severe pneumonia.
CONCLUSION: And with such a masquerading presentation, one can easily miss the diagnosis. To the best of our knowledge, there are very few similar cases reported.