The Effect of Contrast Agents on Dose Calculations of Volumetric Modulated Arc Radiotherapy Plans for Critical Structures

Radiotherapy dose calculation requires accurate Computed Tomography (CT) imaging while tissue delineation may necessitate the use of contrast agents (CA). Acquiring these two sets is a common practice in radiotherapy. This study aims to evaluate the effect of CA on the dose calculations. Two hundred and twenty-six volumetric modulated arc therapy (VMAT) patients that had planning CT with contrast (CCT) and non-contrast CT (NCCT) of different cancer sites (e.g., brain, head, and neck (H&N), chest, abdomen, and pelvis) were evaluated. Treatment plans were recalculated using CCT, then compared to NCCT. The variation in Hounsfield units (HU) and dose distributions for critical structures and target volumes were analyzed using mean HU, mean and maximum relative dose values, D2%, D98%, and 3D gamma analysis. HU variations were statistically significant for most structures. However, this was not clinically significant as the difference in mean HU values was within 30 HU for soft tissue and 50 HU for lungs. Variation in target volumes’ D2% and D98% were insignificant for all sites except brain and nasopharynx. Dose maximum differences were within 2% for the majority of critical structures and target volumes. 3D gamma analysis results revealed that majority of plans satisfied the 2% and 2 mm criteria. CCT may be acquired for VMAT radiotherapy planning purposes instead of NCCT, since there is no clinically significant difference in dose calculations based on either image set

Medical Gas Systems Maintainability Risks in Healthcare Facilities: A Design Optimization Approach

Medical gas pipeline systems (MGPSs) are crucial for operating healthcare facilities as life-saving systems. The sustainability of MGPSs mandates optimum performance by reducing maintenance and repairs. Since faulty design is inventible, healthcare facilities endure several design-caused maintenance issues that endanger the sustainability of healthcare services and maintenance life cycle costs. These design decisions could have been avoided if proper consideration for maintenance had been applied. Eleven experts participated in semi-structured interviews guided by Staticized Group Techniques to identify and evaluate the maintenance issues. The results included identifying 52 design-related maintenance issues that pose maintainability risks. The findings primarily fall under emergency gas supply availability, future expansion readiness, and accessibility of maintenance. The most critical issue found is the excessive cutting-outs of the pipelines when upgrading the system. For new healthcare facilities, the results of this research provide practical help for designers to avoid MGPS issues. A scarcity of benchmark research and geographical factors are some limitations to this study

Magnetic charged particles of optical spherical antiferromagnetic model with fractional system

In this article, we first consider approach of optical spherical magnetic antiferromagnetic model for spherical magnetic flows of ? \Upsilon -magnetic particle with spherical de-Sitter frame in the de-Sitter space S 1 2 {{\mathbb{S}}}_{1}^{2}. Hence, we establish new relationship between magnetic total phases and spherical timelike flows in de-Sitter space S 1 2 {{\mathbb{S}}}_{1}^{2}. In other words, the applied geometric characterization for the optical magnetic spherical antiferromagnetic spin is performed. Moreover, this approach is very useful to analyze some geometrical and physical classifications belonging to ? \Upsilon -particle. Besides, solutions of fractional optical systems are recognized for submitted geometrical designs. Geometrical presentations for fractional solutions are obtained to interpret the model. These obtained results represent that operation is a compatible and significant application to restore optical solutions of some fractional systems. Components of models are described by physical assertions with solutions. Additionally, we get solutions of optical fractional flow equations with designs of our results in de-Sitter space S 1 2 {{\mathbb{S}}}_{1}^{2}. © 2021 Shao-Wen Yao et al., published by De Gruyter.20B110006; National Natural Science Foundation of China, NSFC: 71601072; King Saud University, KSUFunding information : This study was funded by National Natural Science Foundation of China (No. 71601072) and Key Scientific Research Project of Higher Education Institutions in Henan Province of China (No. 20B110006).Bandar Almohsen is supported by Researchers Supporting Project number (RSP-2021/158), King Saud University, Riyadh, Saudi Arabia

Social isolation among adolescents and its association with depression symptoms

Abstract Background Social isolation can be defined as the absence of social interactions, contacts, and relationships with family, friends, and neighbors. According to some studies, social isolation was associated with depressive symptoms. At least one out of every five teenagers suffer from a diagnosable mental health problem that impairs their function. Saudi Arabia has a significant adolescent population; however, there are few studies conducted in Saudi Arabia to assess social isolation and its psychological impact among adolescents. This research is intended to study the prevalence of social isolation among adolescents in Riyadh and its association with depression symptoms. Methods A cross-sectional study was conducted among 483 adolescents living in Riyadh, Saudi Arabia. An online self-administered questionnaire was used, and it was composed of three sections which are sociodemographic characteristics, assessment of social isolation, and assessment of depression symptoms. Results The study reported the prevalence of social isolation among adolescents was 10.14%. The prevalence of depression symptoms among adolescents was high (31.68%). There was a significant association between social isolation and symptoms of depression among the studied sample (χ 2 = 12.3, p = 0.002). It was found that being a male, living with both parents, and having low income are significant predictors of social isolation among adolescents; with r 2 = 0.08 and p-value < .0001. It was also found that low-income level had a more impact on social isolation among adolescents than other factors (estimate = 1.6). Conclusions A total of 10% of adolescents in Riyadh are socially isolated. There is a significant association between social isolation and symptoms of depression among the studied adolescents. Symptoms of depression can be predicted by social isolation.  Recommendations The Ministry of Health and the Ministry of Education in Saudi Arabia should work together to conduct educational intervention programs for adolescents about mental health, the importance of social interaction, and the drawbacks of social isolation. These topics should also be involved in the curriculum of secondary schools

Knowledge and barriers to screening for colorectal cancer among individuals aged 40 years or older visiting primary healthcare clinics in Al-Khobar, Eastern Province

BACKGROUND: Colorectal cancer (CRC) ranks third as the most common cancer in the world and the 4th most common cause of deaths from cancer. In Saudi Arabia, CRC is the most common cancer in males and the third most common in females. Early screening reduces the risk of CRC and death. However, there is a lack of awareness of CRC screening in Saudi Arabia. The objective of this study was to determine the knowledge, practices, and barriers to CRC screening using the Health Belief Model (HBM). MATERIALS AND METHODS: This study enrolled Saudis aged 40 years or older visiting PHCCs in Al-Khobar. Data were collected using a self-administered questionnaire or a direct interview of the selected participants. Information sought included sociodemographics, past CRC screening, CRC knowledge, and HBM items. Data analysis was done using SPSS; the Chi-squared test and ANOVA were used to determine statistical significance. RESULTS: A total of 206 of the individuals approached completed the questionnaire. The average age was 51.1 years, and 51% were males. Only 10% reported that a physician had provided information on CRC prevention or discussed/recommended screening for CRC, and 10% had undergone screening for CRC. Seventy-five percent of respondents had heard of CRC, and 74% said that CRC was preventable. Regarding the HBM, no significant difference in the mean scores for perceived susceptibility, perceived severity, self-efficacy, and benefits of CRC screening was found by age groups. The mean score for perceived severity was higher for females than males. About 60% of participants were extremely likely to have a screening test for CRC done on the day if recommended by the doctor. CONCLUSION: The knowledge and awareness of CRC screening of the targeted sample is inadequate. Individuals with higher perceived susceptibility, severity of CRC, and perceived benefit of the screening tests were more willing to undergo the test. The highest perceived barrier was having no symptoms, and the lowest was “getting a stool test is too much of a hassle.” These findings underline the importance of having a national screening program and campaigns to deal with the concerns of people and raise awareness of CRC

Coronal Heating as Determined by the Solar Flare Frequency Distribution Obtained by Aggregating Case Studies

Flare frequency distributions represent a key approach to addressing one of the largest problems in solar and stellar physics: determining the mechanism that counter-intuitively heats coronae to temperatures that are orders of magnitude hotter than the corresponding photospheres. It is widely accepted that the magnetic field is responsible for the heating, but there are two competing mechanisms that could explain it: nanoflares or Alfv\'en waves. To date, neither can be directly observed. Nanoflares are, by definition, extremely small, but their aggregate energy release could represent a substantial heating mechanism, presuming they are sufficiently abundant. One way to test this presumption is via the flare frequency distribution, which describes how often flares of various energies occur. If the slope of the power law fitting the flare frequency distribution is above a critical threshold, $\alpha=2$ as established in prior literature, then there should be a sufficient abundance of nanoflares to explain coronal heating. We performed $>$600 case studies of solar flares, made possible by an unprecedented number of data analysts via three semesters of an undergraduate physics laboratory course. This allowed us to include two crucial, but nontrivial, analysis methods: pre-flare baseline subtraction and computation of the flare energy, which requires determining flare start and stop times. We aggregated the results of these analyses into a statistical study to determine that $\alpha = 1.63 \pm 0.03$. This is below the critical threshold, suggesting that Alfv\'en waves are an important driver of coronal heating.Comment: 1,002 authors, 14 pages, 4 figures, 3 tables, published by The Astrophysical Journal on 2023-05-09, volume 948, page 7

SARS-CoV-2 vaccination modelling for safe surgery to save lives: data from an international prospective cohort study

Background: Preoperative SARS-CoV-2 vaccination could support safer elective surgery. Vaccine numbers are limited so this study aimed to inform their prioritization by modelling. Methods: The primary outcome was the number needed to vaccinate (NNV) to prevent one COVID-19-related death in 1 year. NNVs were based on postoperative SARS-CoV-2 rates and mortality in an international cohort study (surgical patients), and community SARS-CoV-2 incidence and case fatality data (general population). NNV estimates were stratified by age (18-49, 50-69, 70 or more years) and type of surgery. Best- and worst-case scenarios were used to describe uncertainty. Results: NNVs were more favourable in surgical patients than the general population. The most favourable NNVs were in patients aged 70 years or more needing cancer surgery (351; best case 196, worst case 816) or non-cancer surgery (733; best case 407, worst case 1664). Both exceeded the NNV in the general population (1840; best case 1196, worst case 3066). NNVs for surgical patients remained favourable at a range of SARS-CoV-2 incidence rates in sensitivity analysis modelling. Globally, prioritizing preoperative vaccination of patients needing elective surgery ahead of the general population could prevent an additional 58 687 (best case 115 007, worst case 20 177) COVID-19-related deaths in 1 year. Conclusion: As global roll out of SARS-CoV-2 vaccination proceeds, patients needing elective surgery should be prioritized ahead of the general population