Investigation of half metallic properties of Tl2Mo(Cl/Br)6 double perovskites for spintronic devices.

The manipulation of electronic device characteristics through electron spin represents a burgeoning frontier in technological advancement. Investigation of magnetic and transport attributes of the Tl2Mo(Cl/Br)6 double perovskite was performed using Wien2k and BoltzTraP code. When the energy states between ferromagnetic and antiferromagnetic conditions are compared, it is evident that the ferromagnetic state exhibits lower energy levels. Overcoming stability challenges within the ferromagnetic state is achieved through the manipulation of negative ΔHf within the cubic state. The analysis of the half metallicity character involves an analysis of band structure (BS) and DOS, elucidating its mechanism through PDOS using double exchange model p-d hybridization. The verification of 100% spin polarization is confirmed through factors such as spin polarization and the integer value of the total magnetic moment. Furthermore, the thermoelectric response, as indicated by the ratios of thermal-electrical conductivity and ZT, underscores the promising applications of these compounds in thermoelectric device applications.

Exosomes in Vascular/Neurological Disorders and the Road Ahead.

Neurodegenerative diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), Huntington's disease (HD), stroke, and aneurysms, are characterized by the abnormal accumulation and aggregation of disease-causing proteins in the brain and spinal cord. Recent research suggests that proteins linked to these conditions can be secreted and transferred among cells using exosomes. The transmission of abnormal protein buildup and the gradual degeneration in the brains of impacted individuals might be supported by these exosomes. Furthermore, it has been reported that neuroprotective functions can also be attributed to exosomes in neurodegenerative diseases. The potential neuroprotective functions may play a role in preventing the formation of aggregates and abnormal accumulation of proteins associated with the disease. The present review summarizes the roles of exosomes in neurodegenerative diseases as well as elucidating their therapeutic potential in AD, PD, ALS, HD, stroke, and aneurysms. By elucidating these two aspects of exosomes, valuable insights into potential therapeutic targets for treating neurodegenerative diseases may be provided.

Prevalence and Awareness of Carpal Tunnel Syndrome Among Adults in Tabuk City of Saudi Arabia: A Cross-Sectional Study.

Background Carpal Tunnel Syndrome (CTS) is a condition when the median nerve is entrapped and compressed within the wrist. It significantly affects the quality of life and work productivity of the affected individuals. Aim This study aimed to assess the prevalence of CTS and the risk factors associated with this condition among the general population in Tabuk City, Saudi Arabia, and to explore their knowledge of the causes, manifestations, and treatment options. Methods This cross-sectional study included male and female adult residents of Tabuk City aged 18 years and above who agreed to participate in the study. Data were collected using an online, self-administered questionnaire that was distributed to the public using different social media platforms. Results In this study, the prevalence of CTS was 3.4%. The presence of chronic diseases was a significant risk factor for the CTS (p = 0.003). Participants having chronic diseases were 6.370 times more likely to develop CTS (AOR: 6.370, 95% CI: 2.048 to 19.817). The participants had good levels of awareness about the causes (89.3%), clinical manifestations, and treatment of CTS (92.2%). There was a significant association between the level of knowledge about the causes of CTS and gender (p=0.014). Females (74.3%) showed a higher level of knowledge than males (25.7%). As well, the young (18-25) age group (67.9%) was more significantly aware of the causes of CTS in comparison to the other age groups (p=0.023). Conclusion The prevalence of carpal tunnel syndrome among the adult population in Tabuk City, Saudi Arabia, was 3.4%, and the significant underlying risk factors were chronic diseases such as diabetes mellitus, hypothyroidism, and rheumatoid arthritis. The level of awareness of CTS was satisfactory.

Comparison of laboratory biomarkers for the prediction of in-hospital mortality and severity of acute pulmonary embolism: A multi-center study.

OBJECTIVES: To assess the specificity and sensitivity of prognostic biomarkers in individuals diagnosed with acute pulmonary embolism (PE). METHODS: This study retrospectively enrolled 162 patients from the 741 patients who were hospitalized with acute PE and diagnosed using pulmonary computed tomography (CT) angiogram at 5 hospitals in Saudi Arabia between January 2015 and December 2019. Pulmonary embolism patients classified into survivor and non-survivor groups. Neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and red cell distribution width (RDW) were all recorded and were compared between the groups. The evaluation of mortality prediction, sensitivity, and specificity was carried out by employing receiver operating characteristic curves. RESULTS: The variables NLR and RDW exhibited a statistically significant correlation with increased mortality and disease severity. A total of 8 patients among the 162 patients died. At the cut-off value of 5.5, NLR was showed an association with all-cause mortality, demonstrating a sensitivity of 75% and a specificity of 82%. At the cut-off value of 18.15, RDW was found to be significantly associated with all-cause mortality, displaying a sensitivity of 63% and a specificity of 88%. CONCLUSION: Multiple parameters have been implicated in the mortality and severity of PE. Our study revealed a statistically significant association between NLR, RDW, and PE mortality. These tests are easily accessible and may provide insights into the mortality associated with PE.

Predictors of Outcomes After Coronary Artery Bypass Grafting: The Effect of Concomitant Mitral Repair.

Background Ischemic mitral regurgitation (IMR) or functional MR intensity with or without repair increases the risk of coronary artery bypass grafting (CABG), and if the contaminant is undertaken, it doubles the risk of the surgery. This study aimed to characterize patients with concomitant CABG and mitral valve repair (MVR) and assess the surgical and long-term outcomes. Methods We conducted a cohort study from 2014 to 2020 on 364 patients who underwent CABG. A total of 364 patients were enrolled and divided into two groups. Group I (n= 349) included patients with isolated CABG, and Group II included patients who underwent CABG with concomitant mitral valve repair (MVR) (n= 15). Results Regarding preoperative presentation, most patients were male: 289 (79.40%), hypertensive 306 (84.07%), diabetic 281 (77.20%), dyslipidemic 246 (67.58%), presenting with NYHA classes III-IV: 200 (54.95%), and upon angiography, found to have the three-vessel disease: 265 (73%). Regarding their age mean± SD and Log EuroSCORE median (Q1-Q3), they had a mean age of 60.94± 10.60 years and a median score of 1.87 (1.13-3.19). The most prevalent postoperative complications were low cardiac output 75 (20.66%), acute kidney injury (AKI) 63 (17.45%), respiratory complications 55 (15.32%), and atrial fibrillation (AF) 55 (15.15%). Regarding long-term outcomes, most patients reported class I NYHA 271 (83.13%) and an echocardiographic decrease in MR severity. Patients with a CABG + MVR were significantly younger (53.93± 15.02 vs. 61.24± 10.29 years; P= 0.009), had a lower ejection fraction (33.6 [25-50] vs. 50 [43-55] %; p= 0.032), and had a higher prevalence of LV dilation (32 [9.17%]). EuroSCORE was significantly higher in patients with mitral repair (3.59 [1.54-8.63] vs. 1.78 (1.13-3.11); P= 0.022). The mortality percentage was higher with MVR but did not attain statistical significance. Intraoperative CPB and ischemic durations were longer in the CABG + MVR group. Furthermore, neurological complications were higher in patients with mitral repair (4 (28.57%) vs. 30 (8.65%), P= 0.012). The study's follow-up duration median was 24 (9-36) months. The composite endpoint occurred more frequently in older patients (HR: 1.05 [95% CI: 1.02-1.09]; 0.001), patients with low ejection fraction (HR: 0.96 [95% CI: 0.93-0.99]; P= 0.006) and in patients with preoperative myocardial infarction (MI) (HR: 2.3 [95%: 1.14- 4.68]; P= 0.021). Conclusion Most IMR patients benefited from CABG and CABG + MVR, as evident by NYHA class and echocardiographic follow-up. CABG + MVR had a higher Log EuroSCORE risk with increased intraoperative cardiopulmonary bypass (CPB) and ischemic durations, which may have played a role in increasing the incidence of postoperative neurological complications. On follow-up, no differences were reported between the two groups. However, age, ejection fraction, and a history of preoperative MI were identified as factors affecting the composite endpoint.

Potential therapeutic benefit of ursodeoxycholic acid in the management of non hepato-biliary upper gastrointestinal disorders.

OBJECTIVES: To examine the potential therapeutic effects of ursodeoxycholic acid (UDCA) on diseases of the esophagus, stomach, and duodenum. METHODS: A search was conducted using EBSCO, Medline, PubMed, Google Scholar and Web of Science as well as international guidelines using MESH terms for treatment of UDCA for diseases of the upper gastrointestinal disorders in adult humans without regard to publication language or date restrictions. RESULTS: A total of 256 articles and 22 guidelines were initially identified, and 221 were excluded. Final revision of 13 articles and 22 guidelines confirmed that UDCA is found to have a cytoprotective role in Barret's esophagus within esophageal disorders, improves abdominal pain in functional dyspepsia, and does not alter Helicobacter pylori colonization or inflammation. Conflicting results are noted regarding the role of UDCA in the duodenum as chemopreventive treatment for familial adenomatous polyposis, with polyps regressing and their growth characteristics improving with low doses (10-25 mg/kg/day). On the contrary, no positive effect was noted upon the combination with Celecoxib and with doses of 1000-2000 mg or 20-30 mg/kg/d. Gastrointestinal side effects were predominantly reported. No side effects necessitated hospitalization or ICU admission. CONCLUSION: Ursodeoxycholic acid has a limited therapeutic role in functional dyspepsia. There is promising evidence that it may serve as a chemopreventive for Familial adenomatous polyposis and Barret's esophagus, although further research is needed to confirm these findings.PROSPERO No.: CRD 42021267689.

Prevalence of Low Back Pain Among University Attendants in Tabuk City During 2023: A Cross-Sectional Study in Saudi Arabia.

BACKGROUND: College students are at a higher risk of suffering low back pain (LBP). Assessing the magnitude of the problem and the associated risk factors can help reduce the suffering and disability in future doctors. AIM: This study was conducted to investigate the prevalence and related factors of LBP among medical students in the University of Tabuk and emphasize the need for targeted interventions that could help alleviate the burden of LBP among the students and improve their quality of life. METHODS: This cross-sectional study used an online well-structured, self-report questionnaire to collect the respondents' data. The questionnaire explored the participants' sociodemographic factors, lifestyle, and the severity of LBP-related disability using the modified Oswestry Low Back Pain Disability Questionnaire (Oswestry Disability Index (ODI)) score. RESULTS: The prevalence rate of LBP was 26.8%. The independent factors that significantly increased the probability of LBP included overweight/obesity (odds ratio (OR): 1.696, 95% confidence interval (CI): 1.086 to 2.648, p = 0.020) and stretching exercises (OR: 1.784, 95% CI: 1.104 to 2.883, p = 0.018). The independent predictors that significantly increased the severity of ODI included married marital status (p = 0.007), back surgery (p = 0.031), and higher pain intensity (p < 0.001). CONCLUSIONS: We found that the prevalence rate of LBP among our sample was around 26%. This rate is approximate to the rates reported in previous studies. Furthermore, the activities most affected by LBP were sitting, standing, and lifting. Future studies should explore other risk factors and attempt to determine the onset of pain. A longitudinal study design is recommended to identify the onset of developing LBP.

Effect of Normal and Rubberized Concrete Properties on the Behavior of RC Columns Strengthened with EB CFRP Laminates and Welded Wire Mesh under Static Axial Loading.

The huge amounts of old and damaged tires spread worldwide has caused many complex environmental risks. The old tires have been converted to crumb rubber (CR) and tire recycled steel fiber (RSF) to facilitate their use. This study used CR to partially replace natural sand in reinforced (RC) columns. Externally bonded (EB) carbon-fiber-reinforced polymer (CFRP) laminates, welded wire mesh (WWM), and RSF were used to enhance the axial behavior of the tested columns to overcome the concrete deficiencies resulting from the inclusion of the CR instead of natural sand. Eighteen columns were prepared and tested to discuss the effects of strengthening type, CR content, RSF, and strengthening area on the axial behavior of the RC columns. Certain columns were internally reinforced with WWM, while others were externally strengthened with EB CFRP laminates. Partially or fully EB CFRP laminates were used to strengthen the columns. Moreover, one column was cast with NC and 0.2% RSF to investigate the role of RSF in confining the column. The results demonstrated a concrete strength reduction for the rubberized concrete (CRC) as the CR content increased. Conversely, the strengthened columns experienced higher load capacities than the corresponding un-strengthened ones cast with the same concrete mix. Moreover, adding 2% RSF to the NC mix could enhance the column capacity, although it decreased the concrete strength. Furthermore, using two CFRP layers increased the load capacity and ductility of the strengthened columns. The strengthened column cast with 50% CR showed the highest load efficiency (334.3% compared to the un-strengthened one).

Nurses' professional values scale‒three: Validation and psychometric appraisal among Saudi undergraduate student nurses.

Objectives: Since the nursing professional values have garnered attention as a principal criterion for safe‒quality nursing practice, it was measured using the Nurses Professional Values Scale‒three. We aimed to validate and ascertain the psychometric indicators of the Arabic version of the Nurses Professional Values Scale-three among Saudi student nurses. Method: This methodological study recruited student nurses using convenience sampling from two nursing colleges at KSA. About 438 valid questionnaires were returned out of 500 questionnaires which were distributed over students in a formal day class time; representing a response rate of 87.6%. A 2‒fold cross‒validation process was adopted. A transcultural process was conducted. Face, content, and construct validity using exploratory and confirmatory factor analyses were used. Convergent and discriminant validity were also assessed. The reliability of the scale was assessed using Cronbach's alpha. Results: Face validity was achieved. The content validity of items ranged from .83 to 1.00, while it was .96 for the overall scale. The exploratory factor analysis yielded a scale containing 28 items with a three‒factor model, explaining 74.5% of the total variance. Confirmatory factor analysis confirmed that three‒factor solution had an adequate model fit (CMIN/df = 1.98; RMSEA = .065; SRMR = .039, CFI = .972, and GFI = .968). Convergent validity and discriminant validity were achieved. Cronbach's alpha values were .89, .90, .90, and .96 for activism, caring, professionalism, and the overall scale, respectively. Conclusion: Adequate levels of reliability and validity of the Arabic version of the Nurses Professional Values Scale-three were established, indicating the appropriateness of using this version to assess the professional values among Saudi and other Arabic‒speaking nurses.

Investigation of Antibiotic Resistome in Hospital Wastewater during the COVID-19 Pandemic: Is the Initial Phase of the Pandemic Contributing to Antimicrobial Resistance?

Since the COVID-19 pandemic started, there has been much speculation about how COVID-19 and antimicrobial resistance may be interconnected. In this study, untreated wastewater was sampled from Hospital A designated to treat COVID-19 patients during the first wave of the COVID-19 pandemic alongside Hospital B that did not receive any COVID-19 patients. Metagenomics was used to determine the relative abundance and mobile potential of antibiotic resistant genes (ARGs), prior to determining the correlation of ARGs with time/incidence of COVID-19. Our findings showed that ARGs resistant to macrolides, sulfonamides, and tetracyclines were positively correlated with time in Hospital A but not in Hospital B. Likewise, minor extended spectrum beta-lactamases (ESBLs) and carbapenemases of classes B and D were positively correlated with time, suggesting the selection of rare and/or carbapenem-resistant genes in Hospital A. Non-carbapenemase blaVEB also positively correlated with both time and intI1 and was copresent with other ARGs including carbapenem-resistant genes in 6 metagenome-assembled genomes (MAGs). This study highlighted concerns related to the dissemination of antimicrobial resistance (AMR) during the COVID-19 pandemic that may arise from antibiotic use and untreated hospital wastewater.

Effect of Waste Basalt Fines and Recycled Concrete Components on Mechanical, Water Absorption, and Microstructure Characteristics of Concrete.

In this paper, the recycled fine aggregates and powders produced from crushing old basaltic concrete and natural basalt were used to produce new concrete. The sand was partially replaced by two types of recycled wastes at five percentages: 0%, 20%, 40%, 60%, and 80%. The cement was partially replaced by recycled powders and silica fume (SF) at four percentages: 0, 5%, 10%, and 20%. The concrete strengths and water absorption were obtained at several curing ages. The obtained results emphasized the positive effects of increasing the curing time on enhancing the concrete properties, regardless of the types or the waste sources. Moreover, the recycled powders retarded the hydration reaction. In addition, the recycled fine aggregates and powders could achieve about 99.5% and 99.3% of the ordinary concrete strength and enhance the tensile strength. Furthermore, the mix containing 40% of recycled fine concrete aggregate diffused the highest contents of both calcium and silicate, which led to enhancing the interfacial transition zone (ITZ) and concrete properties, compared to the other tested mixes. Finally, the water absorption of all tested concrete mixes decreased with an increase in the curing age, while the mixes integrating 10% and 20% of SF experienced the lowest values of water absorption.

Effect of Shear and Pure Bending Spans on the Behaviour of Steel Beams with Corrugated Webs.

The shear span-to-effective depth ratio is known to modulate the shear behaviour of steel beams with corrugated webs (SBCWs). However, present design standards for SBCWs do not adequately address this issue. The impact of shear span-to-effective depth ratio and pure bending spans on the failure mechanism of SBCWs was investigated in this study. Under four-point bending, three beams with shear-span-to-effective-depth-ratios ranging from 1.65 to 2.5 were examined to investigate the relationship between shear and bending spans and failure mechanisms. ANSYS software was used to create finite element models for the tested SBCWs using the finite element technique. In addition, the experimental findings are compared to two codes, specifically DASt-Rishtlinie015 and EN 1993-1-5. Moreover, an analytical section comprised of the creation of a three-dimensional (3D) finite element model (FEM) was implemented. Finally, a parametric study using the verified FE model was conducted to assess the impact of shear and pure bending spans on the overall behaviour of SBCWs. As a result, the shear span and horizontal fold length of CWSBs are key components for determining the strength and failure modes of beams. Furthermore, the load capabilities and stiffness of CWSBs were more greatly affected by increasing the shear span than by increasing the pure bending one.

Anti-bacterial activity of essential oils against multidrug-resistant foodborne pathogens isolated from raw milk.

The presence of pathogenic bacteria in food is considered as a primary cause of food-borne illness and food quality deterioration worldwide. The present study aimed to determine the effectiveness of five essential oils (EOs) against multidrug-resistant foodborne pathogens. In the current study Gram-negative bacteria (Escherichia, Enterobacter, Citrobacter, Proteus, Pseudomonas, and Klebsiella) and the Gram-positive bacteria Staphylococcus were isolated from raw milk and biochemically characterized. The anti-bacterial effect of different antibiotics and EOs (thyme, oregano, lemongrass, mint, and rosemary) was determined using the standard disc diffusion method. The antibiogram study revealed that Gram-negative bacteria were highly resistant to penicillin while Staphylococcus was resistant to streptomycin, amoxicillin, and lincomycin. Moderate resistance was observed to doxycycline, amikacin, enrofloxacin, kanamycin and cefixime. Isolates were found less resistant to gentamycin, chloramphenicol, and ciprofloxacin. EOs showed a broad range of antimicrobial activity against all bacteria except P. aeruginosa. Of these, thyme was more effective against most of the multi-drug resistant bacterial strains and formed the largest zone of inhibition (26 mm) against Escherichia followed by oregano oil (18 mm) against Staphylococcus (p<0.05). Klebsiella spp and Citrobacter spp showed resistance to mint and lemongrass oil respectively. The EOs such as lemongrass, mint and rosemary were less active against all the bacteria. The findings of the recent study suggest the use of EOs as natural antibacterial agents for food preservation.

Flexural Response and Failure Analysis of Solid and Hollow Core Concrete Beams with Additional Opening at Different Locations.

It is essential to make openings in structural concrete elements to accommodate mechanical and electrical needs. To study the effect of these openings on the performance of reinforced concrete (RC) elements, a numerical investigation was performed and validated using previous experimental work. The effect of the position and dimension of the opening and the beam length on the response of the beams, loads capacities, and failure modes was studied. The simulated RC beams showed different responses, loads capacities, and failure modes depending on the position and dimension of the opening. The transversal near support opening (TNSH) and longitudinal holes (LH) showed lower effects on the load capacities of the beams than the transversal near center opening (TNCH). The supreme reduction percentages of the load capacity (µu%) for beams with TNCH and TNSH were 37.21% and 30.34%, respectively (opening size = 150 × 150 mm2). In addition, the maximum µu% for beam with LH was 17.82% (opening size = 25% of the beam size). The TNSH with a width of less than 18.18% of the beam shear span (550 mm) had trivial effects on the beam's load capacities (the maximum µu% = 1.26%). Although the beams with combined LH and TNCH or LH and TNSH showed different failure modes, they experienced nearly the same load reductions. Moreover, the length of the beam (solid or hollow) had a great effect on its failure mode and load capacity. Finally, equations were proposed and validated to calculate the yield load and post-cracking deflection for the concrete beams with a longitudinal opening.

Performance of Plain Concrete and Cement Blocks with Cement Partially Replaced by Cement Kiln Dust.

The growth of the construction industry has led to the greater consumption of natural resources, which has a direct or indirect negative impact on the environment. To mitigate this, recycled or waste materials are being used as a partial substitute in the manufacture of concrete. Among these waste materials is cement kiln dust (CKD), which is produced during cement production. This study investigated the potential benefits of replacing part of the cement with CKD in two construction applications, i.e., plain concrete and cement blocks. This reflects positively on cost, energy, and the environment, since putting CKD in a landfill damages agricultural soil and plant respiration. In this study, an experimental program was carried out to study how replacing various percentages of ordinary portland cement (OPC) with CKD affected the compressive strengths, the tensile strengths, and the air contents of concrete and cement blocks. Although the results showed that the compressive and tensile strengths decreased as the amount of CKD increased, the air content of the concrete increased, which showed that 5% CKD was suitable for such applications. The results were used to propose two equations that approximate the concrete and cement block compressive strengths according to the CKD replacement percentage.

Impact of work environment perceptions and communication satisfaction on the intention to quit: an empirical analysis of nurses in Saudi Arabia.

OBJECTIVE: In consideration of the current nursing shortage in Saudi Arabia, we aimed to investigate the association among perceptions of work environment, communication satisfaction, and intentions to quit nursing profession among nurses. In addition, we aimed to investigate the mediating effect of communication satisfaction on the association between nurses' perception of work environment and their intentions to quit nursing profession. METHODS: This predictive correlational study was conducted at one of the major hospitals in Saudi Arabia from January 2020 to March 2020. It included a convenience sample of 367 full-time registered nurses who completed three types of close-ended questionnaires. We used IBM SPSS version 24.0 to analyze the collected data. Regression analyses were used to test the study's hypotheses. All regression assumptions were assessed and confirmed. Significance for all tests was set at p ≤ .05. RESULTS: The findings indicated an affirmative association between work environment perception and communication satisfaction (b = .764, p < .05) among nurses. In addition, findings showed that work environment perception (b = -.187, p < .05) and communication satisfaction (b = -.226, p < .05) have negative impacts on the nurses' intentions to quit; indicating that as work environment perception or communication satisfaction increases, the intention to quit decreases among nurses. Further, a mediation effect of communication satisfaction on the relationship between work environment perception and intention to quit was confirmed. CONCLUSION: This study presents a novel conceptual framework developed based on the literature about the predisposing factors for nurses' intentions to quit nursing profession. Our results suggest that work environment perception and communication satisfaction among the most contributing factors for nurses resignation. Effective communication was established as a crucial factor for establishing attractive and healthy working environment. Nursing managers can benefit by applying these findings to develop appropriate strategies to inhibit the shortage of nurses in Saudi Arabia.

Pedagogical development in local anaesthetic training in paediatric dentistry using virtual reality simulator.

PURPOSE: With the advancements in technology, dental pedagogy has also evolved, and new learning technologies have emerged. Virtual reality (VR) as an education tool in dentistry is underutilised. VR as an adjunct in local anaesthesia (LA) teaching in paediatric dentistry has not been investigated. The study aimed to investigate dental student's perception of dental LA VR simulation on a paediatric patient and to determine whether this can improve students learning experience. METHODS: Seventy-one students participated in a self-administered questionnaire before and after the use of dental LA VR simulator. Descriptive analysis was performed to determine the perceptions of experience gained through VR. The data were tabulated, graphed, and analysed using SPSS and GraphPad Prism software. RESULTS: The study noted that 89.9% of participants perceived that it would improve their LA skills. After using dental LA VR, 83.1% of participants experienced more engaged in the learning activity, and 55.0% of participants agreed/strongly agreed that it improved their understanding of anatomical landmarks. Around 56.4% of participants agreed/strongly agreed that it added value compared with traditional LA teaching methods. CONCLUSION: It can be concluded that the use of VR simulation can enhance students engagement and learning experience in paediatric dentistry settings and can be used as an additional means of LA training.

Estimating the minimum number of SARS-CoV-2 infected cases needed to detect viral RNA in wastewater: To what extent of the outbreak can surveillance of wastewater tell us?

There is increasing interest in wastewater-based epidemiology (WBE) of SARS-CoV-2 RNA to serve as an early warning system for a community. Despite successful detection of SARS-CoV-2 RNA in wastewaters sampled from multiple locations, there is still no clear idea on the minimal number of cases in a community that are associated with a positive detection of the virus in wastewater. To address this knowledge gap, we sampled wastewaters from a septic tank (n = 57) and biological activated sludge tank (n = 52) located on-site of a hospital. The hospital is providing treatment for SARS-CoV-2 infected patients, with the number of hospitalized patients per day known. It was observed that depending on which nucleocapsid gene is targeted by means of RT-qPCR, a range of 253-409 positive cases out of 10,000 persons are required prior to detecting RNA SARS-CoV-2 in wastewater. There was a weak correlation between N1 and N2 gene abundances in wastewater with the number of hospitalized cases. This correlation was however not observed for N3 gene. The frequency of detecting N1 and N2 gene in wastewater was also higher than that for N3 gene. Furthermore, nucleocapsid genes of SARS-CoV-2 were detected at lower frequency in the partially treated wastewater than in the septic tank. In particular, N1 gene abundance was associated with water quality parameters such as total organic carbon and pH. In instances of positive detection, the average abundance of N1 and N3 genes in the activated sludge tank were reduced by 50 and 70% of the levels detected in septic tank, suggesting degradation of the SARS-CoV-2 gene fragments already occurring in the early stages of the wastewater treatment process.

Draft genome sequence of a multidrug-resistant emerging pathogenic isolate of Vibrio alginolyticus from the Red Sea.

The marine ecosystem is a growing reservoir of antimicrobial-resistant bacteria, and thus an emerging risk to human health. In this study, we report the first draft genome sequence of multidrug-resistant Vibrio alginolyticus strain OS1T-47, isolated from an offshore site in the Red Sea. The draft genome of V. alginolyticus OS1T-47 is 5 157 150 bp in length and has DNA G + C content of 44.83%. Strain OS1T-47 possesses 22 antimicrobial resistance genes, including those associated with multidrug-resistant efflux pumps.