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Abstract Plain flaps (PFs) significantly increase camber, enhancing lift and aerodynamic performance when deployed. In Darrieus Vertical Axis Wind Turbines (VAWTs), which perform efficiently in low-speed, turbulent wind conditions, structural modifications like PFs can improve efficiency. This study explores plain flaps with 10-20-degree deflections at different chord lengths to enhance the NACA 2412 aerofoil’s performance. Using Unsteady Reynolds-Averaged Navier-Stokes (URANS) equations and the Shear Stress Transport (SST) k-ω turbulence model, simulations were conducted across high (Re ≈ 2.71 × 105), medium (Re ≈ 1.35 × 105), and low (Re ≈ 5.4 × 104) Reynolds numbers (Re). The 0.7–10 and 0.8–10 configurations significantly improved torque and Cp. At a Tip Speed Ratio (TSR) of 2.5, the 0.8–10 configuration increased the Cp by 19.51% over the flapless NACA 2412 without PF. The 0.7–10 configuration achieved the highest Cp across all TSRs, while a three-blade setup improved Cp by 43% compared to four- and five-blade configurations. The modified blades demonstrated consistent torque gains across all Re, proving the effectiveness of blade shape modifications in enhancing VAWT efficiency, particularly under fluctuating wind conditions, indicating the potential of PF-modified blades in improving small-scale wind turbine performance in varied urban environments.

Abstract Purpose The aim of this study is to investigate and highlight the most important factors influencing the candidate’s selection for residency matching by program directors of surgical and non-surgical specialties in Saudi Arabia. Method This cross-sectional study was conducted in the Central, Eastern, Western, Northern, and Southern regions of Saudi Arabia from February 1, 2023, to August 31, 2023. A total of sixty-one program directors completed a questionnaire, which was adapted and validated from a previous study with permission and tailored to meet the objectives of this research. Results The mean age of the study population was 40.2 years, with surgical specialty program directors being older at 41.7 years and nonsurgical specialty program directors being younger at 39.6 years. In both cases, the highest importance was given to ‘Applicant’s attitude and professionalism’, followed in surgical specialties by ‘Doing clinical rotations in the PD institution’ and ‘Performance in clinical rotation during internship’ in non-surgical specialties. with a mean score of 4.13 and 4.95, respectively. The importance of ‘The impression/opinion of current residents’ has had a certain importance in both specialties. While the number of research projects was prioritized more by surgical PDs (38.6%) compared to non-surgical PDs (29.4%). Conclusion This study highlights the critical role of professionalism and a positive attitude in clinical rotations and interviews for program acceptance in Saudi Arabia. The significance of letters of recommendation and research focus varies between surgical and non-surgical program directors. Program directors should adopt effective recruitment strategies that incorporate practical implications during internships.

Background Medical education was affected worldwide by the coronavirus disease 2019 (COVID-19) pandemic. The sudden announcement of the lockdown resulted in a sudden, unplanned shift to online education. The study aimed to explore the perceptions of the faculty and medical students regarding the experience of utilizing online education at the College of Medicine (CoM), King Saud University, Saudi Arabia. Methods A cross-sectional study was conducted in 2022 with the faculty and medical students in the CoM, King Saud University. The students’ survey was distributed using Google Forms. The questionnaire consisted of six sections with a total of 28 questions that included closed-ended, 5-point Likert scale, and binary “yes” and “no” questions: (1) demographic data, (2) using online education before COVID-19, (3) using of online education during COVID-19, (4) student perceptions of E-learning during COVID-19 pandemic, (5) impact of online education on clinical teaching, and (6) preference in future. The faculty survey was distributed electronically by E-mail through the university’s official E-mail. The faculty survey consisted of 17 questions divided into “Demographic Information” and “Experience with E-Learning before and after COVID-19.” Results A total of 302 students responded to the survey, with most being from year 4 (30%). Students spent more than 10 h using online learning platforms during the pandemic, compared with 1–3 h before the pandemic. The most used online learning resource indicated by students was YouTube (75%), with Zoom being the most preferred platform (48%). The main benefit of online teaching based on students’ responses was that it saves students’ time (88%), while lack of contact with teachers (43%) was a barrier. 76.2% of students indicated satisfaction with the online learning experience during COVID-19. Male students showed more satisfaction than females with the learning experience during COVID-19 (P = 0.029). Almost all students (90%) wanted to continue with online learning post-COVID-19. For the faculty survey, 61 faculty members completed the survey. Overall, the faculty positively viewed online teaching and e-learning interactions. About 39.4% identified giving both live and recorded sessions during COVID-19. About 65.57% of faculty used Zoom to conduct sessions. Regarding preference, 34% preferred e-learning compared to an actual classroom setup for theoretical lectures, and 33% preferred e-learning for problem-based learning lectures. Almost half of the faculty rated their experience as poor for clinical and practical sessions. For problem-based lectures, 34% of faculty rated their interaction with students as poor during online learning compared to the actual classroom. Conclusions Despite the challenges, medical students and faculty perceived the sudden shift to online education due to COVID-19 as satisfactory. However, further efforts are needed to improve the utilization and implementation of online education in medical education and regularly monitor its effectiveness.

Abstract This article proposes a polarization-insensitive compact Metamaterial (MM) energy harvester that can be used seamlessly in the S-band and C-band frequencies. It is important to focus on the limitations of many current designs of harvesters, which need to be overcome. The existing devices are large and often operate in a single frequency band, while their Energy Harvesting (EH) efficiency is low. The proposed harvester solves these problems using smart technology, using a rectangle strip with two gaps, each containing 50 Ω resistors for efficient energy collecting. Also, four hexagonal ring resonators are embedded into the cross-dumbbell configuration, connecting them with strip lines. Smaller rectangular rings surround these hexagonal rings, each with gaps labelled g1–g4. Despite its sophisticated design, the size of this harvester is (10 × 10) mm2 only. This harvester operates at frequencies of 3.5 GHz and 5.5 GHz, demonstrating remarkable absorption responses across varying polarizations and incident angles in both transverse electric (TE) and transverse magnetic (TM) modes. The simulation results indicated impressive energy harvesting efficiencies of 97% at 3.5 GHz and 98% at 5.5 GHz. In addition, experiments in an anechoic chamber with a 3 × 3 array (30 × 30) mm2 were used to confirm the efficiencies empirically. The simulated and measured results showed a strong correlation, confirming the reliability of the proposed design. The proposed MM harvester is distinguished by its high efficiency, polarization-insensitive behaviour, and compactness, making it very promising for many applications in EH.

Abstract At present, the availability of nonrenewable sources and their usage for electric vehicle technology is reducing gradually because of their disadvantages are more environmental pollution, direct effect on human health, less reliability, and taking more time to start functioning. So, in this article, the proton exchange membrane fuel cell (PEMFC) is considered for the automotive application because of its advantages quick startup, more power density, more safety to handle, high efficiency, and capability of operating at very low operational temperature conditions. However, the drawback of PEMFC is very difficult to identify the accurate MPP position of the fuel system. Here, the improved variable step genetic algorithm is added with the adaptive neuro-fuzzy inference system for tracking the operational point of the proposed system with high efficiency. These hybrid MPPT controller features are easy to understand, more accurate, have a better dynamic response, and have low design complexity. The evaluated proposed MPPT controller operational efficiency, and settling time of the converter voltage at different fuel stack temperature conditions are 98.7402%, and 0.01607 s respectively. Finally, the boost converter is used in this work to enhance the voltage supply capability of the entire system. The proposed system is investigated by applying the MATLAB tool.

Abstract Due to its nutritional value and health benefits, the date palm (Phoenix dactylifera L.) is an essential dietary food crop throughout Middle Eastern and African countries. Consumers are concerned about the possible microbial contamination of dates, especially since most dates arriving in local markets are unprocessed. The absence of processing increases the possibility of microbial contamination, which raises the probability of microbial contamination. This study aims to analyze and evaluate the variability of fungal and bacterial microbiota identified in the most popular date palm fruits in Saudi Arabia. The study assessed ten date variety fruits from the most popular date palm varieties for consumption in Saudi Arabia and analyzed the microbial count. Morphological and molecular characterization and comparison of nuclear ribosomal DNA internal transcribed spacer (ITS) sequences identified 78 fungi, including 36 distinct species across 15 fungal genera. Alternaria, Fusarium, Curvilaria, Aspergillus, and Penicillium were the most frequent genera among the ten fruit cultivars studied, according to ITS-rDNA sequence analysis. Furthermore, 36 bacterial isolates were obtained from ten date varieties studied, each with a unique colony morphology. These isolates were identified based on sequence alignment and comparison of their 16S rDNA internal spacer regions to those available in public databases. The results showed that the bacterial isolates included 15 species from five bacterial genera. The results suggested that Bacillus, Stenotrophomonas, and Brucella were the prevailing genera among the ten tested fruit varieties. Some bacterial genera, such as Brucella, Achromobacter, and Stenotrophomonas, are well-known potential human pathogens. Chaetomium globosum was also recognized as air pollution causing adverse health effects such as allergies and as the causal agent of human fungal infections among the tested date varieties; the Rashodiah type exhibited the highest fungal contamination, whereas the Sagai variety displayed the lowest fungal contamination. Conversely, the Sukkari, Barhi, and Mejdool varieties were the most contaminated with bacteria among the ten tested varieties, while the Khalas variety showed the least bacterial contamination. To the best of the authors' knowledge, this study provides the initial comprehensive account of the molecular and morphological identification of all fungal and bacterial genera associated with date palm (P. dactylifera) fruits.

Abstract The reliable operation of power systems while integrating renewable energy systems depends on Optimal Power Flow (OPF). Power systems meet the operational demands by efficiently managing the OPF. Identifying the optimal solution for the OPF problem is essential to ensure voltage stability, and minimize power loss and fuel cost when the power system is integrated with renewable energy resources. The traditional procedure to find the optimal solution utilizes nature-inspired metaheuristic optimization algorithms which exhibit performance drop in terms of high convergence rate and local optimal solution while handling uncertainties and nonlinearities in Hybrid Renewable Energy Systems (HRES). Thus, a novel hybrid model is presented in this research work using Deep Reinforcement Learning (DRL) with Quantum Inspired Genetic Algorithm (DRL-QIGA). The DRL in the proposed model effectively combines the proximal policy network to optimize power generation in real-time. The ability to learn and adapt to the changes in a real-time environment makes DRL to be suitable for the proposed model. Meanwhile, the QIGA enhances the global search process through the quantum computing principle, and this improves the exploitation and exploration features while searching for optimal solutions for the OPF problem. The proposed model experimental evaluation utilizes a modified IEEE 30-bus system to validate the performance. Comparative analysis demonstrates the proposed model’s better performance in terms of reduced fuel cost of $620.45, minimized power loss of 1.85 MW, and voltage deviation of 0.065 compared with traditional optimization algorithms.

Abstract The present power production companies are working on renewable energy systems because their features are more reliable for the local energy consumers, high continuity in the energy production, and less cost is required for maitainence. In this article, the proton exchange membrane fuel stack (PEMFS) renewable energy is utilized to supply energy to the automotive systems. Here, the PEMFS is selected because of its merits are high energy density, quick system response concerning the source operational temperature, and more suitable for electric vehicle application. However, the PEMFS supplied voltage is completely nonlinear which is solved by utilizing the modified particle swarm optimization with adaptive neuro-fuzzy inference system (MPSO with ANFIS) controller. This hybridization-based maximum power point tracking controller provides more accuracy, high power point identifying speed, best dynamic response at different fuel stack functioning temperature conditions, and easy maitainence. Here, the fuel stack generated current is very high which is optimized by introducing the new DC–DC converter. The advantages of this DC–DC converter are more voltage transformation ratio, low-level voltage stress appearing across the switches, and wide voltage gain. The overall system is investigated by utilizing the MATLAB/Simulink tool.

Introduction: Excessive gingival display (EGD) is a mucogingival deformity characterized by overexposure of the maxillary gingiva while smiling. This cross-sectional study aimed to identify EGD etiologies and their prevalence in participants at King Saud University, Saudi Arabia. Methods: Adults with a gummy smile, who resided in Saudi Arabia, were nonsmokers, had good overall health, and had all their maxillary anterior teeth were eligible for inclusion. Participants were first screened by phone, and those who met the eligibility criteria were further screened at the Dental University Hospital (King Saud University, Riyadh, Saudi Arabia). The demographic characteristics of all eligible participants were recorded. Participants were further subjected to extraoral examination, which included gingival display (GD), vertical maxillary excess (VME), hypermobile upper lip (HUL), smile line, altered passive eruption (APE), gingival overgrowth, and short upper lip (SUL). Intraoral examination included periodontal pocket depth and bleeding upon probing. Student’s t-test was used to compare the mean GD values across the main etiologies (VME, HUL, APE, and SUL). Results: All 123 participants (mean age: 23.1 ± 0.2 years; 74 females) had EGD (i.e., GD ≥ 4 mm), of whom 55 (44.7 %) had a single etiology, and the remaining 68 (55.3 %) had > 1 etiology. APE was the predominant etiology (n = 90, 73.2 %) in the study population. Of these (n = 90), APE alone was prevalent in 29 (32.2 %) participants, whereas the remaining patients had APE in combination with other EGD etiologies (n = 61; 67.8 %). The presence of more than one EGD etiology in the same participant was associated with greater GD. The VME and HUL were significantly associated with smile line classes (p

Background: The RHD gene is one of the most complex blood group genes. The molecular background of the RHD gene in RhD-negative and RhD-positive individuals varies within and among different populations. Knowing the molecular basis of the RHD gene in a specific population is required to establish effective genotyping methods. While the molecular basis has been revealed in many ethnicities, such as Caucasians and Black Africans, it still requires elucidation in Arabs. Objectives: The aim of this study was to gain insights into the molecular basis of RhD-positive and RhD-negative phenotypes in Saudi donors. Materials and Methods: Conventional serological tests were used to determine the Rh phenotypes in 136 Saudi donors by typing D, C, c, E, and e antigens. Multiplex-PCR and Single Specific Primer-PCR were used to detect the presence of exons 3, 4, and 7 and the hybrid Rhesus box gene, respectively, in RhD-negative and/or RhD-positive samples. Results: Of the 136 samples, 70 were RhD positive and 66 were RhD negative. None of the RhD-negative donors had any of the three tested exons, whereas the hybrid Rhesus box gene was detected in all, indicating the zygosity status of the RHD deletion allele. The hybrid Rhesus box gene was detected in 79% of the RhD-positive individuals, suggesting high frequencies of RHD-negative haplotypes. Conclusions: The study findings indicate that Saudis with the RhD-negative phenotype are likely to have an entire RHD deletion in the homozygous state. However, a more comprehensive analysis of variant RHD alleles in the Saudi population is required to implement effective and dedicated molecular RHD typing strategies.

Abstract At present, conventional energy production is absent because of the more hazardous gases released into the environment, the high effect on human health, more cost required for maintenance, plus less usefulness for highly populated areas. So, the Renewable Energy Sources are more focused for the present automotive industry application. In this work, the Proton Exchange Membrane Fuel Stack is considered for analyzing the proposed DC–DC converter circuit. The advantages of this fuel stack are high energy density, fast functioning nature, more robustness, and more usefulness for the various water membrane conditions of the fuel stack. However, the disadvantages of the fuel stack are excessive current generation, plus more current conduction losses. So, the wide voltage supply single switch power converter is introduced in this work for optimizing the current production of the fuel stack network. The merits of this converter circuit are high stability, good reliability, low voltage appearing across the switches, plus a uniform power supply. Here, the converter switching pulses are obtained by proposing the Modified Continuous Step Change Adaptive Fuzzy Logic with Grey Wolf Optimization hybrid controller. This controller provides high maximum power extraction efficiency from the fuel stack which is equal to 99.421%. Also, this controller's Maximum Power Point Tracking time is 0.0285 s.

Abstract The development of DC microgrids is reliant on multi-input converters, which offer several advantages, including enhanced DC power generation and consumption efficiency, simplified quality, and stability. This paper describes the development of a multiple input supply based modified SEPIC DC–DC Converter for efficient management of DC microgrid that is powered by two DC sources. Here Multi-Input SEPIC converter offers both versatility in handling output voltage ranges and efficiency in power flow, even under challenging operating conditions like lower duty cycle values. These features contribute to the converter's effectiveness in managing power within a DC microgrid. In this configuration, the DC sources can supply energy to the load together or separately, depending on how the power switches operate. The detailed working states with equivalent circuit diagrams and theoretical waveforms, under steady-state conditions, are shown along with the current direction equations. This paper also demonstrates the typical analysis of large-signal, small-signal, steady-state modeling techniques and detailed design equations. The proposed configuration is validated through the conceptual examination using theoretical and comprehensive MATLAB simulation results. Detailed performance analysis has been done for different cases with various duty ratios. Finally, to show the competitiveness, the multi-input SEPIC topology is compared with similar recent converters.

Background: Gastroesophageal reflux disease (GERD) is one of the most prevalent gastrointestinal disorders worldwide. It manifests when the lower esophageal sphincter malfunctions, causing the stomach’s contents to reflux into the esophagus, lead to discomforting symptoms. Heartburn and regurgitation are the typical symptoms of GERD. This study aims to determine the prevalence of GERD and assess its risk factors. Materials and Methods: This cross-sectional study was conducted at IMSIU, Saudi Arabia. An online survey was distributed to the students’ email addresses to determine the prevalence of GERD, its related risk factors, and understanding of its symptoms. Results: One thousand five hundred and thirty-three (1533) students participated in the survey. The prevalence of GERD was 34.6%. The majority (79.7%) of the respondent students had heard of GERD. Stress is believed to be a factor in developing GERD by 35.7% of students. Heartburn was the predominant symptom of GERD (76.2%). No association existed between the socio-demographic traits of those with GERD except for age and academic year. Conclusions: It is imperative to raise public awareness of the disorder’s characteristics and its modifiable risk factors to prevent the emergence of GERD and its complications.

Abstract Considering different applications that require varied power and voltage conversion levels between AC grids and AC loads, AC–AC power conversion between AC grids has become an inevitable technology of energy management systems. An isolated converter for performing AC-to-AC transmission is proposed with minimal components for reduced losses and enhanced system efficiency. Single-phase direct buck-boost AC to AC converter with minimum components constituted with two dual IGBT control units (IGBT 1–IGBT 4), inductor (Lf), and capacitor (Cf) is proposed in this work. The MATLAB/Simulink platform is used to provide in-depth analysis of the circuit and components along with the design guidelines, and simulation outcomes of this proposed model. The voltage gains of G = 2.13, power factor of 0.97, and overall efficiency of 98% are achieved in the proposed system with minimum components of 4 switches, 2 conductors, and 1 capacitor and inductor respectively. The obtained results are compared with existing technology to evaluate the proposed system.

Abstract The conventional MPPT method has drawbacks, such as that under partial shading conditions, several peaks occur and identifying the global peak is difficult. It may converge to a local peak and lead to poor conversion efficiency and tracking efficiency. Implementation of a hybrid algorithm by integrating P&O and metaheuristic algorithms can perform better under partial shading conditions. But the tracking speed is low and the response time is longer. To mitigate the issues mentioned above, a new hybrid algorithm has been suggested that integrates GWO and a modified fast terminal sliding mode controller (MFTSMC). The suggested method with three phase ILBC is incorporated into the PV system. The MATLAB tool is employed to experiment with this study. The performance of GWO-MFTSMC is analysed through MATLAB/ SIMULINK and compared with the performance of ANN-FTSMC and PSO-FTSMC algorithm based MPPT techniques. A hardware prototype is developed and tested for 5 × 200 W solar PV modules with the GWO-MFTSMC algorithm. The proposed method conversion efficiency is 99.72% and 96.15% under simulation and hardware realisation, respectively, which is higher than the ANN-FTSMC and PSO-FTSMC methods.

Abstract Solar energy is the most promising among many renewable energy sources to meet the increasing demand. Photovoltaic (PV) based power generating solutions are expected to gain popularity as a power source for different applications, including independent and grid connected loads, due to their cleanliness, high performance, and high dependability. The efficacy of photovoltaic systems is impacted by several elements, including geographical location, positioning, shadowing effects, and local climate conditions. In order to fulfil the demands of loads, an interleaved boost converter is utilized, which has a reduced number of filters with less stress on the devices. Solar powered systems employ several maximum power point tracking (MPPT) methodologies. However, when there is partial shading, many power peaks arise, which complicates the identification of the overall peak. Although MPPT approaches are designed to measure and maintain the global maximum power point (GMPP), there are still significant oscillations observed around the GMPP with subpar settling time, tracking efficiency, and conversion efficiency. In this work, novel hybrid MPPT technique called artificial neural network supported adaptable stepped-scaled perturb and observe (ANN-ASSPO) method and water cycle optimization based perturb and observe (WCO-PO) have been proposed. Artificial neural network (ANN) has been used to determine the best scaling factor in ANN-ASSPO MPPT. Performance is enhanced in ANN-ASSPO MPPT by using the optimum scaling factor, particularly in situations when the irradiance is rapidly changing/partial shading conditions. Similarly, in WCO-PO MPPT water cycle optimization is used to determine the peak power when the PV panel is subjected to partial shading conditions. The performances of proposed hybrid MPPT ANN-ASSPO and WCO-PO techniques have been compared in terms of power generated, output voltage, average settling time and conversion efficiency. The MATLAB/Simulink tool is employed to carry out the experiment for this study.

Aim: This study aims to identify and address the predictors that promote or prevent the utilization of dental services in primary health care (PHC) centers located in Riyadh, Saudi Arabia, with an ultimate goal to increase the uptake of oral health care (OHC) services. Methodology: Registration data from 99 PHC centers was used. For each patient visiting a PHC center, information on the number of dental visits was captured. Continuous data was summarized as means, medians, and ranges, and categorical data as frequencies (%). The strength of association was reported as an incidence rate ratio (IRR) with 95% confidence interval (CI) and a p-value. Further analysis was conducted to illustrate the association between dental care visits and factors found independently significant in the final multivariate model using Karl Pearson correlation coefficient and t-test. All tests were two-sided and a p-value of p

Abstract In response to the growing demand for fast-charging electric vehicles (EVs), this study presents a novel hybrid multimodule DC–DC converter based on the dual-active bridge (DAB) topology. The converter comprises eight modules divided into two groups: four Insulated-Gate Bipolar Transistor (IGBT) modules and four Metal–Semiconductor Field-Effect Transistor (MESFET) modules. The former handles high power with a low switching frequency, while the latter caters to lower power with a high switching frequency. This configuration leverages the strengths of both types of semiconductors, enhancing the converter’s power efficiency and density. To investigate the converter’s performance, a small-signal model is developed, alongside a control strategy to ensure uniform power sharing among the modules. The model is evaluated through simulation using MATLAB, which confirms the uniformity of the charging current provided to EV batteries. The results show an impressive power efficiency of 99.25% and a power density of 10.99 kW/L, achieved through the utilization of fast-switching MESFETs and the DAB topology. This research suggests that the hybrid multimodule DC–DC converter is a promising solution for fast-charging EVs, providing high efficiency, power density, and switching speed. Future studies could explore the incorporation of advanced wide bandgap devices to handle even larger power fractions.

Many patients with obstructive sleep apnoea (OSA) remain undiagnosed and thus untreated, and in part this relates to delay in diagnosis. Novel diagnostic strategies may improve access to diagnosis. In a multicentre, randomised study, we evaluated time to treatment decision in patients referred for suspected OSA, comparing a mandibular movement (MM) monitor to respiratory polygraphy, the most commonly used OSA detection method in the UK. Adults with high pre-test probability OSA were recruited from both northern Scotland and London. 40 participants (70 % male, mean±SD age 46.8 ± 12.9 years, BMI 36.9 ± 7.5 kg/m2, ESS 14.9 ± 4.1) wore a MM monitor and respiratory polygraphy simultaneously overnight and were randomised (1:1) to receive their treatment decision based on results from either device. Compared to respiratory polygraphy, MM monitor reduced time to treatment decision by 6 days (median(IQR): 13.5 (7.0–21.5) vs. 19.5 (13.7–35.5) days, P = 0.017) and saved an estimated 29 min of staff time per patient.

Background: Noise pollution is a serious issue that faces healthcare centers. It is associated with detrimental effects on both the patient's and the healthcare provider's mental and physical well-being. It could also negatively impact the physician's decision-making. Aim: There are no similar studies conducted in the past 5 years in Saudi Arabia. This is the first study to measure noise levels and deem them pollutants in an emergency care center in Saudi Arabia. Method: This cross-sectional study was conducted in the emergency department (ED) of a tertiary care hospital to assess the level of noise pollution. Noise levels were evaluated in the ED by using a calibrated decibel meter device in three selected units including resuscitation, acute care, and pediatrics unit. Noise levels were only measured during weekdays. In each unit, readings were obtained over 24 hours. Results: Over 24 hours, measurements of all assessed units showed that noise levels exceeded WHO guidelines for hospitals, which recommend sound levels below 40 decibels (dB). Among all clinical areas, the pediatric unit exhibited the highest noise spike (97.3 dB), followed by the resuscitation unit (88.5 dB), and the acute care unit (87.3 dB). Conclusion: Noise levels were high in all the assessed units, which places the patient's well-being and recovery at risk. Moreover, high noise levels could contribute to adverse outcomes for the healthcare provider. More studies should focus on assessing the noise levels in other departments and the efficacy of different intervention methods. [SJEMed 2023; 4(2.000): 087-091]

Introduction Appropriate quality and quantity of sleep are critical for good mental health, optimal body functioning, memory consolidation, and other cognitive processes.

Abstract Recurring Listeria outbreaks in the United States is a growing public healthcare concern. Although no associated reported death, 17 were hospitalized out of the 18 reported illnesses in the recent outbreak in 15 US states. The United States has experienced about 30 Listeria outbreaks in the last decade with 524 Listeriosis cases and 80 deaths. The identified origin were ice cream, leafy greens, mushroom, meat slice, dairy products like cheese, packaged salads, cooked chicken, hard‐boiled egg, pork product, frozen vegetable, raw milk, packaged caramel apple, bean sprout and soya products. Although rare, Listeria may lead to serious illness (invasive listeriosis) or death. Listeriosis is critically harmful and medically complicated, especially in the pregnant, the old above 65 years and in the immunocompromised. It could cause premature birth, miscarriage or even neonatal death. Hospitalization is often necessary in the geriatric, being fatal at times. Among Listeria sp., Listeria monocytogenes is often human infection‐associated. It is a gram‐positive, non‐sporulating, motile bacillus opportunistic pathogen. Food‐borne listeriosis is often associated with frozen foods due to its ability to thrive at low temperatures. Hypervirulent strains of L. monocytogenes with an ability to infect the respiratory system (the lungs) was recently reported in the coronavirus disease‐19 patients during the pandemic. L. monocytogenes seemed to have developed antimicrobial resistance to ciprofloxacin and meropenem, possibly acquired through the food chain. An early onset of listeriosis in the newborn is evident in the first 7 days postparturition. As the bacteria colonize the genitourinary tract, majority of such cases result from teratogenic transfer during vaginal delivery. Premature newborns, neonates born outside healthcare facilities and low‐birth‐weight babies were increasingly predisposed to an early onset of listeriosis. Listeria outbreaks were earlier reported in South Africa, Australia and Europe, with an unclear origin of the outbreaks. Social media updates about such outbreaks, the most likely food source, and measures to self‐protect are suggested as preventive measures. The article deals on various such aspects related to listeriosis primarily originating from food, to ensure better public healthcare and human wellness.

Purpose: ARID1B is one of the most frequently mutated genes in intellectual disability cohorts. Thus, far few adult-aged patients with ARID1B-related disorder have been described, which limits our understanding of the disease’s natural history and our ability to counsel patients and their families. Methods: Data on patients aged 18+ years with ARID1B-related disorder were collected through an online questionnaire completed by clinicians and parents. Results: Eighty-seven adult patients with ARID1B were included. Cognitive functioning ranged from borderline to severe intellectual disability. Patients identified through the genetic workup of their child were either mosaic or had a variant in exon 1. New clinical features identified in this population are loss of skill (16/64, 25%) and recurrent patella luxation (12/45, 32%). Self-sustainability data showed that 88% (45/51) could eat independently, and 16% (7/45) could travel alone by public transport. Facial photo analysis showed that patients’ photographs taken at different ages clustered consistently, separate from matched controls. Conclusion: The ARID1B spectrum is broad, and as patients age, there is a significant shift in the medical aspects requiring attention. To address the changing medical needs with increasing age, we have formulated recommendations to promote timely intervention in an attempt to mitigate disease progression.

Objectives: This study aimed to adapt the survey questionnaire designed by Moens et al. (2021) and determine the validity and reliability of the Arabic version of the survey in a sample of the Saudi population experiencing teleworking. Methods: The questionnaire includes 2 sections. The first consists of 13 items measuring the impact of extended telework during the coronavirus disease 2019 (COVID-19) crisis. The second section includes 6 items measuring the impact of the COVID-19 crisis on self-view of telework and digital meetings. The survey instrument was translated based on the guidelines for the cultural adaptation of self-administrated measures. Results: The reliability of the questionnaire responses was measured by Cronbach’s alpha. The construct validity was checked through exploratory factor analysis followed by confirmatory factor analysis (CFA) to further assess the factor structure. CFA revealed that the model had excellent fit (root mean square error of approximation, 0.00; comparative fit index, 1.0; Tucker-Lewis index, 1; standardized root mean squared residual, 0.0). Conclusions: The Arabic version of the teleworking questionnaire had high reliability and good validity in assessing experiences and perceptions toward teleworking. While the validated survey examined perceptions and experiences during COVID-19, its use can be extended to capture experiences and perceptions during different crises.

Abstract An integrated massive multiple-input multiple-output (mMIMO) antenna system loaded with metamaterial (MTM) is proposed in this article for fifth-generation (5G) applications. Besides, achievement of duple negative (DNG) characteristics using a proposed compact complementary split-ring resonator (SRR), a broad epsilon negative metamaterial (ENG) with more than 1 GHz bandwidth (BW), and near-zero refractive index (NZRI) features are presented. The proposed mMIMO antenna consists of eight subarrays with three layers that operate in the 5G mind band at 3.5 GHz (3.40–3.65 GHz) with high port isolation between adjacent antenna elements compared to an antenna that does not use MTM. Each subarray has two patches on the top layer, while the middle and bottom layers have two categories of full and partial ground plans, respectively. Simulated, produced, and tested are 32 elements with a total volume of 184 × 340 × 1.575 mm3. The measured findings reveal that the sub-6 antenna has a better than 10 dB reflection coefficient (S11), a lower than 35 dB isolation, and a peak gain of 10.6 dBi for each subarray. Furthermore, the recommended antenna loaded with MTM has demonstrated good MIMO performance with an ECC of less than 0.0001, total efficiencies of more than 90%, more than 300 MHz bandwidth, and an overall gain of 19.5 dBi.

Objectives: This study aims to evaluate the effectiveness of topical fluoride application and diode laser-irradiation on the hardness of demineralized enamel and to evaluate the esthetic improvement of the white spot lesions (WSLs) using a visual analog scale (VAS). Materials and Methods: Artificial WSLs (3x3 mm) were created on the enamel surface of 45 human third molars. The teeth were randomly assigned into three groups (n = 15): group A, fluoride only; group B, combined therapy of fluoride and diode laser; and group C, control. Vicker’s hardness number (VHN) was measured at baseline, after demineralization and after treatment. To evaluate the esthetic improvement after treatment, 14 raters evaluated each group’s photographs using a 100-millimeter VAS. A one-way ANOVA or Brown-Forsythe and Games-Howell post hoc procedure were performed for statistical analysis. The level of significance was set at α = 0.05 for all tests. Results: Group A mean VHN was significantly higher than groups B and C, and group B was significantly higher than group C (P

Abstract In this article, a symmetric split ring resonator (SRR) based metamaterial (MTM) is presented that exhibits three resonances of transmission coefficient (S21) covering S, C, and X-bands with epsilon negative (ENG) and near zero index properties. The proposed MTM is designed on an FR4 substrate with the copper resonator at one side formed with two square rings and one circular split ring. The two square rings are coupled together around the split gap of the outer ring, whereas two split semicircles are also coupled together near the split gaps. Thus, gap coupled symmetric SRR is formed, which helps to obtain resonances at 2.78 GHz, 7.7 GHz and 10.16 GHz with desired properties of the MTM unit cell. The MTM unit cell's symmetric nature helps reduce the mutual coupling effect among the array elements. Thus, different array of unit cells provides a similar response to the unit cell compared with numerical simulation performed in CST microwave studio and validated by measurement. The equivalent circuit is modelled for the proposed MTM unit cell in Advanced Design System (ADS) software, and circuit validation is accomplished by comparing S21 obtained in ADS with the same of CST. The effective medium ratio (EMR) of 10.7 indicates the compactness of the proposed MTM. A test antenna is designed to observe the effect of the MTM over it. Numerical analysis shows that the proposed MTM have an impact on the antenna when it is used as the superstrate and helps to increase the gain of the antenna by 95% with increased directivity. Thus, compact size, high EMR, negative permittivity, near zero permeability and refractive index makes this MTM suitable for S, C and X band applications, especially for antenna gain with directivity enhancement.

Abstract A couple ring enclosed circular geometric resonator (CRECGR) based dual-band polarization insensitive metamaterial (MM) with high effective medium ratio (EMR), and excellent absorptance is proposed in this study, which can be utilized as a sensor and absorber in the 5G sub-6 GHz frequency range. A circular geometry-based unique patch has been introduced in the proposed unit cell to achieve high polarization insensitive properties with excellent absorption for the 5G sub-6 GHz spectrum. The distinctive feature of this proposed CRECGR unit cell is its simple and unique structure with a high EMR of 11.13, polarization insensitive up to 180°, and epsilon negative (ENG) properties, including a negative refractive index and near-zero permeability for 5G sub-6 GHz applications. Furthermore, this designed unit cell yields excellent absorption properties with high quality factor. The designed MM unit cell is fabricated on low loss Rogers RT5880 printed media with an electrical dimension of 0.089λ × 0.089λ × 0.017λ. The performance of the designed CRECGR metamaterial is determined using Computer Simulation Technology (CST), Advanced Design Software (ADS), and measurements. The CRECGR unit cell offers dual resonances at 3.37 GHz and 5.8 GHz, covering the 5G sub-6 GHz band with ENG, near-zero permeability and negative index. The polarization insensitive properties of the unit cell were also investigated for maximum angle of incidence, which confirmed the identical response. The simulated outcome is verified by experiment with excellent accordance. Moreover, the unit cell performance with a complete backplane is explored, noting a maximum absorption of 99.9% for all normal and oblique incidence waves, suitable for sensing and antenna systems. In addition, the suggested unit cell sensing performance is evaluated using the permittivity-based sensing model. The proposed MM outperforms recent related studies in terms of polarization insensitivity up to 180°, high insensitive absorptivity, high EMR, and sensing applications. These features prove that the proposed CRECGR metamaterial is perfect for 5G Applications.

The failure to treat infectious diseases due to the continual emergence of drug-resistant microbes poses a huge and serious challenge for human health globally. Currently, the discovery and development of natural therapeutic compounds are attracting considerable attention from researchers worldwide. In this project, two types of pollen grains (maize and clover) were evaluated for potential antimicrobial activities. Extracts of both pollen grains were purified using HPLC, which has been shown to have numerous phenolic and flavonoid compounds. Pyro catechol and methyl gallate were detected in high concentrations (1145.56 and 1056.57 µg/mL, respectively) in the maize extract, while caffeic acid, quercetin, and kaempferol (464.73, 393.05, and 390.93 µg/mL, respectively) were among the compounds observed at high concentrations in the clover pollen grains extract. Staphylococcus aureus, Escherichia coli, Salmonella typhi, and Candida albicans were more sensitive to the clover pollen grains extract with inhibition zones of 22 ± 0.2, 18 ± 0.1, 29 ± 0.3, and 42 ± 0.4 mm compared to the size of the inhibitory zones caused by the maize pollen grains extract (19 ± 0.3, 15 ± 0.4, 27 ± 0.1, and 22 ± 0.4 mm, respectively). Moreover, lower MIC values for the clover pollen grains extract were recorded against C. albicans (1.97 ± 0.04 µg/mL), S. aureus (62.5 ± 1.00 µg/mL), and E. coli (62.5 ± 0.07 µg/mL) than the MICs caused by the maize pollen grains extract. The use of a transmission electron microscope revealed that the E. coli that had been treated with the clover pollen grains extract showed changes in its cell walls compared to that treated with the maize pollen grains extract. The clover pollen grains extract exhibited a stronger antioxidant potential, with an IC50 value of 22.18 µg/mL, compared to an IC50 value of 54.85 µg/mL for the maize pollen grains extract, via a DPPH scavenging assay. Regarding anticancer activity, the maize pollen grains extract was revealed to be more effective in terms of inhibiting the human colon cancer cell line HCT-116, with an IC50 value of 67.02 ± 1.37 µg/mL, compared with the observed toxicity caused by the clover extract, with an IC50 value of 75.03 ± 1.02 µg/mL. Overall, the clover pollen grains extract demonstrated potent antibacterial and antioxidant activities, but not anticancer activity, when compared to the maize grains extract. Thus, the current findings related to both types of pollen grains (clover and maize) highlight their potential therapeutic applications for the treatment of certain infectious diseases and malignancies.

Abstract In this article, a novel shaped metamaterial sensor is presented for the recognition of various oils, fluids, and chemicals using microwave frequency. The performance of the designed sensor structure has been studied both theoretically and experimentally, and it works well. A new sample holder for convenient operation is created and located just behind the designed structure. The results of this study performed better than those of prior liquids sensing studies. Various designs were explored using the Genetic Algorithm (GA), and it is embedded in the Computer Simulation Technology (CST) microwave studio, to optimize the optimal dimensions of the resonator. The suggested metamaterial sensor has a good-quality factor and sensitivity in both frequency shifting and amplitude changing. The resonance frequency shifted to 100 MHz between olive and corn oils, 70 MHz between sunflower and palm oils, 80 MHz between clean and waste brake fluids, and 90 MHz between benzene and carbon-tetrachloride chemicals. The quality factor of the sensor is 135, sensitivity is 0.56, and the figure of merit is 76 which expresses its efficient performance. Furthermore, the proposed sensor can sensitively distinguish different liquids by using the frequency shifting property. The study was carried out in three stages: dielectric constant (DK) measurement with the N1500A dielectric measurement kit, simulation of the structure, and experimental test study with the vector network analyzer. Since the recommended sensor has high sensitivity, good quality factor, and excellent performance, hence it can be used in chemical, oil, and microfluidic industries for detecting various liquid samples.

Medication-related osteonecrosis of the jaw (MRONJ) is a major problem that can occur in people taking certain medications such bisphosphonates and denosumab. It can be used to treat osteoporosis or cancer. Bisphosphonate exposure, dental diseases and procedures, age, sex, anatomical factors, medical issues, and hereditary factors are all variables that enhance the risk of MRONJ. Even though MRONJ and antiresorptive medications have a close association, the pathophysiology of MRONJ is unknown. Careful dental preparation and oral hygiene instructions significantly minimize the risk of osteonecrosis of the jaw (ONJ). It is ideal to start antiresorptive treatment after the completion of required dental treatment; it is not contraindicated and carries low risk in patients who are on oral antiresorptive medications for less than three years. Drug holidays are one proposed solution to address MRONJ. However, there is still inadequate evidence to support their effectiveness. The objectives of this literature review are to recognize the main diagnostic principles and risk factors and to review the pathophysiology, protective procedures and treatment modalities related to MRONJ.The following topics are covered in the review: epidemiology, diagnostic criteria, risk factors, pathogenesis and mechanism, MRONJ staging and symptoms, clinical and radiographic findings, treatment strategies, prevention and drug holiday.

Objectives: The aim is to evaluate the knowledge, attitude, and practice (KAP) regarding prevention, diagnosis, and management of COVID-19 in family medicine residents in Riyadh, Saudi Arabia and also to examine the association of the residents' demographic variables with their COVID-19 KAP level. Methods: A cross-sectional survey conducted during July to August 2020 that targeted all family medicine residents who were enrolled in the Saudi board training programs in Riyadh. An online version of a specifically designed questionnaire was distributed to determine the residents' KAP toward COVID-19. Results: A total of 97 of 170 residents responded for a response rate of 57%. The most important results noted from this study are that participants had satisfactory knowledge of COVID-19; but, it was not associated with their demographic characteristics. Most participants demonstrated positive attitudes toward persons having risk factors for COVID-19 and who disclose their exposure (n = 82, 85%). Most participants exhibited good practices except participating in training programs concerning COVID-19 infection prevention and control (n = 46, 47%). Total knowledge scores were significantly affected by feeling tired, lack of confidence in defeating the virus, and persons with risk of COVID-19 infection. There was no significant association between the knowledge and practice. Conclusion: The results demonstrated that family medicine residents in Riyadh overall had good KAP on COVID-19 disease in Riyadh, Saudi Arabia. Such good KAP could help limit viral spread.

Abstract Background Molecular autopsy refers to DNA-based identification of the cause of death. Despite recent attempts to broaden its scope, the term remains typically reserved to sudden unexplained death in young adults. In this study, we aim to showcase the utility of molecular autopsy in defining lethal variants in humans. Methods We describe our experience with a cohort of 481 cases in whom the cause of premature death was investigated using DNA from the index or relatives (molecular autopsy by proxy). Molecular autopsy tool was typically exome sequencing although some were investigated using targeted approaches in the earlier stages of the study; these include positional mapping, targeted gene sequencing, chromosomal microarray, and gene panels. Results The study includes 449 cases from consanguineous families and 141 lacked family history (simplex). The age range was embryos to 18 years. A likely causal variant (pathogenic/likely pathogenic) was identified in 63.8% (307/481), a much higher yield compared to the general diagnostic yield (43%) from the same population. The predominance of recessive lethal alleles allowed us to implement molecular autopsy by proxy in 55 couples, and the yield was similarly high (63.6%). We also note the occurrence of biallelic lethal forms of typically non-lethal dominant disorders, sometimes representing a novel bona fide biallelic recessive disease trait. Forty-six disease genes with no OMIM phenotype were identified in the course of this study. The presented data support the candidacy of two other previously reported novel disease genes (FAAH2 and MSN). The focus on lethal phenotypes revealed many examples of interesting phenotypic expansion as well as remarkable variability in clinical presentation. Furthermore, important insights into population genetics and variant interpretation are highlighted based on the results. Conclusions Molecular autopsy, broadly defined, proved to be a helpful clinical approach that provides unique insights into lethal variants and the clinical annotation of the human genome.

Background: Obstructive sleep apnea is a common disorder frequently encountered in otorhinolaryngology practice. This study was conducted to assess the knowledge and attitudes toward obstructive sleep apnea among otorhinolaryngology trainees in Saudi Arabia. Methods: This was a survey-based cross-sectional study. An online questionnaire was sent in July 2020 via email and WhatsApp instant messaging to all otorhinolaryngology trainee residents in Saudi Arabia. We utilized the previously validated obstructive sleep apnea knowledge and attitudes questionnaire (OSAKA). Results: 32.4% of all email recipients completed the questionnaire and met the inclusion criteria. 66.7% were males, thirty-two participants (53.3%) were at the junior level (R2–R3), and twenty-eight (46.7%) were at the senior level (R4–R5). The mean total knowledge score was 13.98/18. Senior residents had a higher mean total knowledge score than junior residents. Senior residents had a higher mean total attitude score than junior residents. Age, gender, residency program area, and years of previous otorhinolaryngology practice showed no significant differences in terms of knowledge levels and attitudes toward obstructive sleep apnea. Exposure to obstructive sleep apnea surgery and awareness of sleep disorders other than sleep apnea were found to be associated with an increased level of confidence in identifying patients at risk of obstructive sleep apnea and in the ability to manage them. Conclusions: This study describes the current condition of obstructive sleep apnea knowledge and attitudes among otorhinolaryngology residents in Saudi Arabia. Addressing studied elements may improve training outcomes.

Alzheimer’s disease (AD) is a progressive neurological illness that is distinguished clinically by cognitive and memory decline and adversely affects the people of old age. The treatments for this disease gained much attention and have prompted increased interest among researchers in this field. As a springboard to explore new anti-Alzheimer’s chemical prototypes, the present study was carried out for the synthesis of benzoxazole-oxadiazole analogues as effective Alzheimer’s inhibitors. In this research work, we have focused our efforts to synthesize a series of benzoxazole-oxadiazole (1–19) and evaluating their anti-Alzheimer properties. In addition, the precise structures of synthesized derivatives were confirmed with the help of various spectroscopic techniques including 1H-NMR, 13C-NMR and HREI-MS. To find the anti-Alzheimer potentials of the synthesized compounds (1–19), in vitro acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE), inhibitory activities were performed using Donepezil as the reference standard. From structure-activity (SAR) analysis, it was confirmed that any variation found in inhibitory activities of both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) enzymes were due to different substitution patterns of substituent(s) at the variable position of both acetophenone aryl and oxadiazole aryl rings. The results of the anti-Alzheimer assay were very encouraging and showed moderate to good inhibitory potentials with IC50 values ranging from 5.80 ± 2.18 to 40.80 ± 5.90 µM (against AChE) and 7.20 ± 2.30 to 42.60 ± 6.10 µM (against BuChE) as compared to standard Donepezil drug (IC50 = 33.65 ± 3.50 µM (for AChE) and 35.80 ± 4.60 µM (for BuChE), respectively. Specifically, analogues 2, 15 and 16 were identified to be significantly active, even found to be more potent than standard inhibitors with IC50 values of 6.40 ± 1.10, 5.80 ± 2.18 and 6.90 ± 1.20 (against AChE) and 7.50 ± 1.20, 7.20 ± 2.30 and 7.60 ± 2.10 (against BuChE). The results obtained were compared to standard drugs. These findings reveal that benzoxazole-oxadiazole analogues act as AChE and BuChE inhibitors to develop novel therapeutics for treating Alzheimer’s disease and can act as lead molecules in drug discovery as potential anti-Alzheimer agents.

Abstract A quartz crystal adsorbent coated with 5,10,15,20-tetrakis(4-methylphenyl) porphyrin was used to examine the complexation phenomenon of three metallic ions [aluminum(III), iron(III) and indium(III)]. The aim is to select the appropriate adsorbate for metalloporphyrin fabrication. The equilibrium adsorption isotherms of tetrakis(4-methylphenyl) porphyrin were performed at four temperatures (from 300 to 330 K) through the quartz crystal microbalance (QCM) method. Subsequently, the experimental data were analyzed in order to develop a thorough explanation of the complexation mechanisms. The experimental results indicated that the aluminum(III) chloride is the adequate material for metalloporphyrin application. Theoretical investigation was established through physics adsorption models in order to analyze the experimental isotherms. The AlCl3 isotherms were modeled via a single-layer adsorption model which is developed using the ideal gas law. Whereas, the FeCl3 isotherms were interpreted via a single-layer adsorption which includes the lateral interactions parameters (real gas law), indicating the lowest stability of the formed iron-porphyrin complex. The participation of the chloride ions in the double-layers adsorption of InCl3 was interpreted via layer by layer formulation. Interestingly, the physicochemical investigation of the three adopted models indicated that the tetrakis(4-methylphenyl) porphyrin adsorption was an endothermic process and that the aluminum(III) chloride can be recommended for an industrial application because it presents the highest adsorption energy (chemical bonds with porphyrins).

Sclerosing encapsulating peritonitis (SEP) is a rare clinical condition characterized by the formation of a thick, fibrous membrane encasing the intestines, which may lead to intestinal obstruction. The pathogenesis is not completely understood, but various risk factors are well established. However, there are only few reported cases of SEP associated with peritoneal carcinomatosis. Herein, we report a case of a 69-year-old male patient who presented clinically with acute intestinal obstruction 2 years after undergoing a resection procedure for gastric cancer. An abdominal computed tomography revealed findings typical of SEP. Consequently, the patient underwent exploratory laparoscopy, which confirmed the diagnosis of SEP and established the etiology as peritoneal metastases. The patient was managed conservatively, and his symptoms showed some improvement. The patient was at an advanced stage of the disease, and thus remained on palliative care and passed away 1 month later. Although very rare, physicians should consider SEP in their differential diagnoses of intestinal obstruction in patients, particularly in those with a history of intra-abdominal malignancies.

Background: The coronavirus disease of 2019 (COVID-19) has challenged and disrupted medical education worldwide. Objective structured clinical examination (OSCE) is one of the types of assessment for undergraduate medical students that has been conducted for first-year medical students in the College of Medicine. Peer student training on participating in OSCE has been conducted prior to the pandemic. The aim of this study was to assess medical students' perception of online virtual peer student video training on participating in the OSCE. Methods: Medical student's council team prepared a video demonstration on the steps of participating in OSCE. In October 2020, the video was provided online for first-year medical students (n = 302) prior to their OSCE. After the completion of the OSCE exam, a 10 – item questionnaire was distributed on the students' perception on the impact of the peer student video demonstration on students' orientation about the OSCE. The questionnaire was sent by Google Forms. The results were expressed as a percentage on a Likert scale. Results: About 74.17% (n = 224) of students responded to the online questionnaire. More than half of the students (n = 126, 56%) found the steps of conduction of the OSCE well explained, provided the sufficient orientation (n = 121, 54%), and found the video stimulating (n = 122, 54%). In addition, the majority of students (n = 160, 71%) learned and understood the steps of the OSCE and 152 students (68%) found that the video helped introducing them to the concept of OSCE. Almost half the students found that the video helped lowering the stress level before the OSCE (n = 91, 41%), eased the steps of the OSCE (n = 113, 50%), and found that the materials were well prepared and explained (n = 126, 56%). Conclusions: The virtual video demonstration of the OSCE during the COVID-19 pandemic had an overall positive perception from first-year medical students. However, peer student's orientation on the OSCE will continue after the pandemic. Further supports for first-year medical students are needed during the pandemic.

Introduction: Globally speaking, cardiovascular disease is the leading cause of mortality, with coronary artery disease (CAD) contributing to half of the cases. A major complication of CAD is myocardial infarction (MI). The clinical outcomes of MI are predominantly time-dependent; therefore, it is paramount that the general public is familiar with the early symptoms of MI. Aim: The main objective is to gauge the local public awareness of the early symptoms of MI, and their knowledge of the best course of action to be taken from the onset of symptoms. Method: A cross-sectional study was conducted using google forms. Participants were randomly selected through multiple social media platforms. The study included Saudi citizens who were 18 years or older, with no current or prior experience in the health care field. The questionnaire assessed the participants' awareness of 14 risk factors for CAD. The variables investigated were participants' knowledge of the symptoms, causes, appropriate course of action to be taken, and the risk factors of CAD. Results: A total of 1689 participants were involved in this study. Sixty percent were females, and 29.2% were in the age group of 18–24 years. Seventy-three percent of the participants knew the definition of heart attack, and 90% knew that chest pain is a symptom of a heart attack. Approximately, 75% of the participants recognized that hypertension, cigarette smoking, and high cholesterol are the risk factors of MI. In terms of knowledge, Al Madinah province obtained the highest score when compared with other regions. Conclusion: This study showed the overall knowledge and awareness of CAD was suboptimal, indicating that awareness initiatives and patient education of CAD need more work in Saudi Arabia, especially in high-risk groups and lower education groups. More studies are needed to identify the efficiency and population access of different approaches for CAD awareness.

Background: The declaration of the COVID-19 pandemic triggered a global inquiry into the transmission, mortality, risk factors, and management of the disease. Recently, however, attention has shifted toward its long-term consequences. There is a need for a better understanding of the predictors and symptoms of post-COVID syndrome, to ensure appropriate care for patients recovering from COVID-19 beyond the acute phase. Methods: We searched PubMed, Google Scholar, Cochrane databases, and available data in the PROSPERO databases. We also explored the reference lists of included articles and any systematic reviews identified therein. We searched the keywords "Post Covid", "Post COVID syndrome", "Post- Covid" and "PostCOVID", until July 2021. Results: Of 8167 articles, 13 were included. The syndrome affects several systems with variable prevalence. Fatigue and sleep disturbance is the most common symptom of acute post-COVID syndrome, observed in more than two-thirds of patients, while a reduction in quality of life and general health status was noted in up to 69%. Furthermore, a reduced aerobic and diffusion capacity was seen in 38% of patients up to one month after presumed recovery from infection. Radiologically, in up to 52% of patients, a ground-glass opacity (GGO) was noted beyond three months post-infection. The incidence of new psychiatric illness increased from as early as 14 days after infection and up to three or six months. Hearing impairment or loss, whether sensorineural or conductive, was noted in up to 8.3% of patients, and tinnitus was seen in up to 4.2%. Conclusion: Overall, given the variability in the manifestation of post-COVID syndrome, a multidisciplinary team is required to better serve these patients. We therefore urge the establishment of such teams, encompassing internal medicine, pulmonology, cardiology, and neurocognitive services.

This study analyzes aggregate data on trade flows to examine the performance of bilateral free trade agreements (BFTAs) between the United States and 11 BFTA nations in a two-dimensional approach. In line with the literature, this study applies the gravity model and analyzes the effect of the treatment using Poisson pseudo-maximum likelihood (PPML) panel data from 1992 to 2017. We use the PPML as an alternative methodology to an ordinary least squares model, as it can treat zero trade values and lead to unbiased estimates and different consistencies. We consider the trade in goods but excluded services because of the different nature of trade for services. Moreover, this study highlights the quantitative performance of BFTAs without considering the industry level to compare the overall benefits for the trade flows from the U.S. as an exporter to BFTA countries and vice versa. It thus adds to the debate on the effect of FTAs on trade flows and conducts pre-FTA and post-FTA analyses to compare the volumes of exports and imports during both periods. Findings vary according to the direction of trade; notably, some trading partners increased their trading volume to 388%. In sum, this paper provides a collective current state assessment to demonstrate the most plausible reasons for the effects of the 11 BFTAs, in addition to informing policymakers on the lessons learned from each BFTA.

A series of 12 compounds was designed and synthesized, based on 2-mercaptobenzoxazole derivatives containing either the substituted benzenes 4a–d, substituted isatins 5a–f, or heterocycles 6a–b. The in vitro antiproliferative activity of the compounds was evaluated against hepatocellular carcinoma (HepG2), mammary gland cancer (MCF-7), breast cancer (MDA-MB-231), and the epithelioid cervix carcinoma (HeLa) cancer cell lines. Compounds 4b, 4d, 5d, and 6b had the most potent antiproliferative activity, with IC50 values ranging from 2.14 to 19.34 µM, compared to the reference drugs, doxorubicin and sunitinib. Compound 6b revealed a remarkably broad antitumor activity pattern against HepG2 (IC50 6.83 µM), MCF-7 (IC50 3.64 µM), MDA-MB-231 (IC50 2.14 µM), and HeLa (IC50 5.18 µM). In addition, compound 6b showed potent inhibitory activities against EGFR, HER2, VEGFR2, and the CDK2 protein kinase enzymes, with IC50 values of 0.279, 0.224, 0.565, and 0.886 µM, respectively. Moreover, compound 6b induced caspase-dependent apoptosis and cell cycle arrest at the G2/M phase. Finally, a molecular docking simulation was performed for compound 6b to predict the potential ligand–protein interactions with the active sites of the EGFR, HER2, and VEGFR2 proteins.

Background and study Aims: Liver cancer, most commonly known as hepatocellular carcinoma (HCC), was ranked as the sixth most common cancer in Saudi Arabia in 2014. Management of unresectable HCC is multidisciplinary and could include radiofrequency ablation, systemic-targeted therapy, and transarterial chemoembolization (TACE). This study aimed to assess the survival outcome of patients with unresectable HCC undergoing TACE in Saudi Arabia. Patients and Methods: We retrospectively studied patients with unresectable HCC who were treated with TACE between 2004 and 2016. Patient's demographics, etiology of liver disease, Child–Turcotte–Pugh stage, computed tomography scan findings, laboratory results, details of treatment sessions, and follow-up visit data were obtained from the National Liver Disease Research Database. Results: Thirty-nine patients diagnosed with HCC underwent 103 TACE sessions at our hospital. Median overall survival time was 20 months (range 0–98). Median progression-free survival was 9 months (range 1–98). Follow-up imaging revealed progressive disease in 20 patients (54.05%), while 17 had no disease progression, and none had complete resolution. Conclusion: Our results are similar to those of previous studies that reported the benefit of TACE on survival rates of HCC patients. The correlation found between median overall survival and international normalized ratio and bilirubin level could reflect the importance of liver function deterioration effects on outcomes.

Abstract Emergencies in endocrine surgery are rare. Acute neck hematoma may result from recent surgery or spontaneous as with ruptured thyroidal cyst, thyroidal vessel, or parathyroid adenoma. We are reporting a case of acute neck hematoma caused by a ruptured of parathyroid adenoma, which required urgent surgical intervention.

BACKGROUND: Motor vehicle crashes are the third leading cause of death in Saudi Arabia. Motorcycle riders, in particular, are considered more vulnerable than occupants, yet there are no previous studies that have examined the epidemiology of their injuries and outcomes in the country. Better understanding is needed to inform policymakers and guide future prevention programs. OBJECTIVE: Describe patterns of injury among conscious and unconscious patients injured in motorcycle crashes. DESIGN: Retrospective chart review. SETTINGS: Level 1 trauma center in Riyadh. PATIENTS AND METHODS: This retrospective study included all patients involved in motorcycle crashes who were admitted between 2001 and 2017. Medical records were reviewed, and data about injury characteristics, outcomes and healthcare utilization were ascertained. MAIN OUTCOME MEASURES: Injury site and mortality rate. SAMPLE SIZE AND CHARACTERISTICS: 572 patients included 488 males (85.3%) and 232

Objectives This study examines how the results of the Hospital Survey on Patient Safety Culture changed between 2012 and 2019 and identifies organisational factors affecting these changes.Design The study combined the use of quantitative surveys of staff and qualitative interviews with hospital leadership. Secondary data analysis was performed for previous surveys.Setting This study was conducted in a tertiary care teaching multisite hospital in Riyadh, Saudi Arabia.Participants One thousand hospital staff participated in the survey. Thirty-one executive board members and directors and four focus groups of frontliners were qualitatively interviewed.Primary and secondary outcome measures Twelve safety culture dimensions were assessed to study the patient safety culture as perceived by the healthcare professionals. An additional semi-structured interview was conducted to identify organisational factors, changes, and barriers affecting the patient safety culture. Furthermore, suggestions to improve patient safety were proposed.Results Comparing the results revealed a general positive trend in scores from 2012 to 2019. The areas of strength included teamwork within and across units, organisational learning, managerial support, overall perception of safety and feedback and communication about error. Non-punitive response to error, staffing and communication and openness consistently remain the lowest-scoring composites. Interview results revealed that organisational changes may have influenced the answers of the participants on some survey composites.Conclusions Patient safety is a moving target with areas for improvement that are continuously identified. Effective quality improvement initiatives can lead to visible changes in the patient safety culture in a hospital, and consistent leadership commitment and support can maintain these improvements.