Double crosslinked hyaluronic acid and collagen as a potential bioink for cartilage tissue engineering.

The avascular nature of hyaline cartilage results in limited spontaneous self-repair and regenerative capabilities when damaged. Recent advances in three-dimensional bioprinting have enabled the precise dispensing of cell-laden biomaterials, commonly referred to as 'bioinks', which are emerging as promising solutions for tissue regeneration. An effective bioink for cartilage tissue engineering needs to create a micro-environment that promotes cell differentiation and supports neocartilage tissue formation. In this study, we introduced an innovative bioink composed of photocurable acrylated type I collagen (COLMA), thiol-modified hyaluronic acid (THA), and poly(ethylene glycol) diacrylate (PEGDA) for 3D bioprinting cartilage grafts using human nasal chondrocytes. Both collagen and hyaluronic acid, being key components of the extracellular matrix (ECM) in the human body, provide essential biological cues for tissue regeneration. We evaluated three formulations - COLMA, COLMA+THA, and COLMA+THA+PEGDA - for their printability, cell viability, structural integrity, and capabilities in forming cartilage-like ECM. The addition of THA and PEGDA significantly enhanced these properties, showcasing the potential of this bioink in advancing applications in cartilage repair and reconstructive surgery.

Improved pediatric ICU mortality prediction for respiratory diseases: machine learning and data subdivision insights.

The growing concern of pediatric mortality demands heightened preparedness in clinical settings, especially within intensive care units (ICUs). As respiratory-related admissions account for a substantial portion of pediatric illnesses, there is a pressing need to predict ICU mortality in these cases. This study based on data from 1188 patients, addresses this imperative using machine learning techniques and investigating different class balancing methods for pediatric ICU mortality prediction. This study employs the publicly accessible "Paediatric Intensive Care database" to train, validate, and test a machine learning model for predicting pediatric patient mortality. Features were ranked using three machine learning feature selection techniques, namely Random Forest, Extra Trees, and XGBoost, resulting in the selection of 16 critical features from a total of 105 features. Ten machine learning models and ensemble techniques are used to make accurate mortality predictions. To tackle the inherent class imbalance in the dataset, we applied a unique data partitioning technique to enhance the model's alignment with the data distribution. The CatBoost machine learning model achieved an area under the curve (AUC) of 72.22%, while the stacking ensemble model yielded an AUC of 60.59% for mortality prediction. The proposed subdivision technique, on the other hand, provides a significant improvement in performance metrics, with an AUC of 85.2% and an accuracy of 89.32%. These findings emphasize the potential of machine learning in enhancing pediatric mortality prediction and inform strategies for improved ICU readiness.

Prefabricated Fibula Flap vs Bone-Driven and Delayed Implant Installation for Jaw Reconstruction.

Importance: Restoration of dental occlusion and oral rehabilitation is the ultimate goal of functional jaw reconstruction. Objective: To evaluate the prefabricated fibula flap (PFF) technique in occlusion-driven jaw reconstruction for benign or previously treated malignant disease. Design, Setting, and Participants: This cohort study was conducted from January 2000 to December 2019 at the University of Alberta Hospital and Institute of Reconstructive Sciences in Medicine in Edmonton, Alberta, Canada, among patients who underwent PFF or bone-driven and delayed osseointegrated implant installation (BDD). Patients were followed up for a minimum of 1 year after occlusal rehabilitation. Data were analyzed from July 2021 to June 2022. Exposures: Patients underwent BDD or PFF, which consists of osseointegrated dental implant installation and skin grafting of the fibular bone 3 to 6 months before jaw tumor resection or defect reconstruction. The implant osseointegration is completed at the time of jaw reconstruction, allowing for full reconstruction, loading, and restoration of the dental occlusion in the immediate postoperative period. Main outcomes and Measure: Safety, effectiveness, accuracy, timeliness of occlusal reconstruction, and aesthetic appeal were compared between PFF and BDD. Groups were compared for the following variables: postoperative complications, number of bony segments used, number of procedures needed, total operative time, time to occlusal rehabilitation, and number of implants installed, exposed, lost, and used (ie, exposed implants - lost implants). Aesthetic appeal was assessed using standardized full-face and profile digital photographs taken before and 6 to 12 months after the operation and analyzed by 3 naive raters. Results: Among 9 patients receiving PFF (mean [SD] age, 43.3 [13.0] years; 7 men [77.8%]) and 12 patients receiving BDD (mean [SD] age, 41.9 [18.0] years; 8 men [66.7%]), the overall complication rate was similar (4 patients [44.4%] vs 3 patients [25.0%], respectively; relative risk, 1.78 [95% CI, 0.52 to 6.04]). The number of patients with implant loss was similar between PFF and BDD groups (0 patients vs 3 patients [25.0%], respectively; difference, -25.0 percentage points [95% CI, -48.4 to 9.7 percentage points]). PFF had a clinically meaningful faster mean (SD) occlusal rehabilitation compared with BDD (12.1 [1.9] months vs 60.4 [23.1] months; difference, -48.3 months [95% CI, -64.5 to -32.0 months]). The mean (SD) difference in preoperative to postoperative aesthetic score was similar between PFF and BDD groups (-0.8 [1.5] vs -0.2 [0.8]; difference, -0.6 [95% CI, -1.6 to 0.4]). Conclusions and Relevance: This study found that PFF compared with BDD was a safe, effective, and aesthetic reconstructive option for patients with benign or previously treated jaw malignant tumors. This technique may provide rapid occlusal reconstruction and oral rehabilitation.

Optimization of eco-friendly concrete with recycled coarse aggregates and rubber particles as sustainable industrial byproducts for construction practices.

In this technology era, sustainable construction practices have become quite imperative. The exploration of alternative materials to reduce the environmental footprint is of paramount importance. This research paper delves into an exhaustive investigation concerning the utilization of recycled coarse aggregates (RCA) and rubber particles (RP) in concrete. It contributes to the growing body of knowledge aimed at fostering sustainable development in the construction industry by reducing waste, promoting recycling, and mitigating the environmental footprint of building materials. The objective of the study is to evaluate the potential benefits and limitations associated with incorporating these materials, thereby providing a sustainable alternative to conventional concrete. In this research, construction and demolition waste were recycled and used as RCA as a fractional switch of natural coarse aggregate (NCA) from 0% to 100%, with an increment of 20% replacement of NCA in concrete. The RP received from discarded tires generated as automobile industry waste were used as a volumetric fractional substitution of sand in concrete from 0% to 20%, with a 5% increment. No pre-treatment for RCA and RP was carried out before their utilization in concrete. A total of 26 mixes, including control concrete without NCA and RP, with a design strength of 40 MPa, were prepared and tested. Concrete mixes were examined for workability, density, mechanical, and durability properties. It was found that the concrete with 60% RCA and 10% RP showed satisfactory results in evaluation with the strength parameters of control concrete, as the compressive strength obtained for this concrete mix is 40.18 MPa, similar to the control mix. The optimization for RCA and RP was conducted using Response Surface Methodology (RSM). The major concern observed was a rise in water absorption with an increase in the percentage replacement of NCA and natural sand by RCA and RP. Findings from the investigation illustrate a promising prospect for the use of RCA and RP in concrete applications, displaying competent mechanical properties and enhanced durability under certain conditions, offering a viable option for environmentally friendly construction practices. However, the research also sheds light on some constraints and challenges, such as the variability in the quality of RCA and the necessity for meticulous quality control to ensure the reliability and consistency of the end product. It is discerned that further refinement in processing techniques and quality assurance measures is pivotal for mainstream adoption of RCA and RP in concrete construction.

Procedural sedation programme minimising adverse events: a 3-year experience from a tertiary paediatric emergency department.

INTRODUCTION: A well-developed procedural sedation programme in the paediatric emergency department can minimise adverse events. We examined how adherence to current best evidence ensures safe delivery of paediatric sedation in a newly established tertiary paediatric hospital. METHODS: Our sedation service uses a robust provider training and privileging system, standardised policy and procedures and rigorous data collection all within an evidence-based clinical governance process. We examined sedation data from the first 3 years of operation. RESULTS: From July 2018 to May 2022, ketamine was used in 3388 of the 3405 sedations. The mean age of sedated children was 5.5 years (range 6 months to 17.8 years) and common indications were closed reduction of fractures and laceration repairs. A total of 148 (4.37%, 95% CI 3.68% to 5.06%) adverse events were documented, including 88 (2.59%, 95% CI 2.06% to 3.13%) cases of vomiting, 50 (1.48%, 95% CI 1.07% to 1.88%) cases related to airway and breathing with 40 (1.18%, 95% CI 0.82% to 1.54%) cases of oxygen desaturation, 6 (0.18%, 95% CI 0.04% to 0.32%) cases of laryngospasm, 4 (0.12%, 95% CI 0% to 0.23%) cases of apnoea. CONCLUSION: This study presents a large single-centre dataset on the use of intravenous ketamine in paediatric procedural sedation. Adhering to international standards and benchmarks for provider skills and training, drug administration and monitoring facilities, with a strict clinical governance process, optimizes patient safety.

Experimental investigation of H3PO4 activated papaya peels for methylene blue dye removal from aqueous solution: Evaluation on optimization, kinetics, isotherm, thermodynamics, and reusability studies.

This investigation is centered on the effectiveness of methylene blue (MB), a cationic dye, adsorbed from an aqueous media by H3PO4 activated papaya skin/peels (PSPAC), with initial pH (2-10), contact time (30-180 min), MB dye concentration (varying from 10 to 50 mg/L), and MB dose (0.1-0.5 gm). The findings show that the best optimal conditions for MB dye removal occur at a 6 pH, 0.3 gm dose of PSPAC adsorbent for 10 mg/L MB dye concentration, with 90 min of contact time. To optimize and validate the extraction efficiency of MB dye, a response surface methodology (RSM) study was conducted using a central composite design (CCD) with a regression model showing R2 = 0.9940. FT-IR spectroscopy shows, CO, and O-H stretching functional groups while FE-SEM is assessed to supervise morphological features of the PSPAC adsorbent. The peak adsorption capacity with 46.95 mg/g for the Langmuir isotherm model conveniently satisfies the adsorption process with R2 = 0.9984 while with R2 = 0.999, a kinetic model, pseudo-second-order, confirms MB dye adsorption by PSPAC adsorbent. Moreover, thermodynamic parameters including ΔGᵒ, ΔH°, and ΔS° were computed and found to be spontaneous and exothermic. Furthermore, regeneration studies employed with NaOH (0.1 M) and HCl (0.1 M) solution media show an acceptable MB removal efficiency consecutive up to three cycles. The study highlights that H3PO4 papaya skin/peel (PSPAC) is an effectual, sustainable, reasonably available biosorbent to remove industrial cationic dyes disposal.

The Effect of Crosslinking Density on Nasal Chondrocytes' Redifferentiation.

Hydrogels appear to be an attractive class of biomaterial for cartilage tissue engineering due to their high water content, excellent biocompatibility, tunable stiffness, etc. The crosslinking density of the hydrogel can affect their viscoelastic property, and therefore potentially impact the chondrogenic phenotype of re-differentiated chondrocytes in a 3D microenvironment through physical cues. To understand the effect of crosslinking densities on chondrocytes phenotype and cellular interaction with the hydrogel, this study utilized a clinical grade thiolate hyaluronic acid and thiolate gelatin (HA-Gel) hydrogel, crosslinked with poly(ethylene glycol) diacrylate to create various crosslinking densities. The HA-Gel hydrogels were then mixed with human nasal chondrocytes to generate neocartilage in vitro. The influence of the hydrogel crosslinking density and the viscoelastic property on the cell behaviours on the gene and matrix levels were evaluated using biochemistry assays, histology, quantitative polymerase chain reaction (qPCR) and next-generation sequencing (RNA seq). In general, the differences in the storage modulus of the HA-Gel hydrogel are not enough to alter the cartilaginous gene expression of chondrocytes. However, a positively correlated trend of PPAR-γ gene expression to the crosslinking density was measured by qPCR. The RNA-seq results have shown that 178 genes are significantly negatively correlated and 225 genes are positively correlated to the crosslinking density, which is worth investigating in the future studies.

COVID-19 vaccine hesitancy in the Saudi Arabian population.

This study aimed to measure the level of vaccine hesitancy among the Saudi population using the WHO Vaccine Hesitancy Scale (VHS). A cross-sectional study using a modified vaccine hesitancy scale (VHS) was conducted among Saudi Arabian residents between April 4 and May 24, 2021. The relationship between participants' willingness to uptake COVID-19 vaccines and their demographics, awareness of COVID-19, and health status was evaluated. The chi-square test was employed to compare categorical variables and logistic regression for the associations of demographical characteristics with acceptance of the vaccine. We received a total of 1657 completed responses. 1,126 participants (68%) were vaccinated, of which 19% were vaccinated with one dose only, and 49% were fully vaccinated (with two doses). Safety concerns and worries about side effects were higher among the hesitant group (p<0.001). 96% of the participants from the willing group were not hesitant to have the vaccine, whereas in the same group, 70% thought they had good health and the vaccine was not needed. Logistic regression analysis revealed that participants with chronic diseases had lower odds of being willing to be vaccinated (OR=0.583, p-value 0.04). The study findings suggest key factors associated with COVID-19 vaccine hesitancy in the Saudi population and can help public health authorities plan strategies to minimize vaccine hesitancy and improve awareness about vaccine acceptance.

Vaccine evaluation and genotype characterization in children infected with rotavirus in Qatar.

BACKGROUND: We characterized and identified the genetic and antigenic variations of circulating rotavirus strains in comparison to used rotavirus vaccines. METHODS: Rotavirus-positive samples (n = 231) were collected and analyzed. The VP7 and VP4 genes were sequenced and analyzed against the rotavirus vaccine strains. Antigenic variations were illustrated on the three-dimensional models of surface proteins. RESULTS: In all, 59.7% of the hospitalized children were vaccinated, of which only 57.2% received two doses. There were no significant differences between the vaccinated and non-vaccinated groups in terms of clinical outcome. The G3 was the dominant genotype (40%) regardless of vaccination status. Several amino acid changes were identified in the VP7 and VP4 antigenic epitopes compared to the licensed vaccines. The highest variability was seen in the G3 (6 substitutions) and P[4] (11 substitutions) genotypes in comparison to RotaTeq®. In comparison to Rotarix®, G1 strains possessed three amino acid changes in 7-1a and 7-2 epitopes while P[8] strains possessed five amino acid changes in 8-1 and 8-3 epitopes. CONCLUSIONS: The current use of Rotarix® vaccine might not be effective in preventing the infection due to the higher numbers of G3-associated cases. The wide range of mutations in the antigenic epitopes compared to vaccine strains may compromise the vaccine's effectiveness. IMPACT: The reduced rotavirus vaccine effectiveness necessitate regular evaluation of the vaccine content to ensure optimal protection. We characterized and identified the genetic and antigenic variations of circulating rotavirus strains in comparison to the Rotarix vaccine strain that is used in Qatar. The study highlight the importance for regular monitoring of emerging rotavirus variants and their impact on vaccine effectiveness in young children.

Extent of exposure to scented candles and prevalence of respiratory and non-respiratory symptoms amongst young university students.

BACKGROUND: Incense burning such as scented candles are commonly used in Arabian Gulf regions as it is thought to produce relaxing effects on people's mood. This study is conducted to examine the prevalence of scented candles' usage, extent of exposure and its effects on individuals' health based on symptoms prevalence in young university students. MATERIAL AND METHOD: A cross-sectional study was conducted on university students from different regions in Saudi Arabia. Data was collected in March 2020 using an online questionnaire survey adapted from The European Community Respiratory Health Survey-II (ECRHS-II). Inclusion criterion for recruitment was students with non-smoking status. Descriptive statistics were used to report demographic data on the extent of exposure to scented candles (in terms of frequency and duration) and the presence of symptoms. Multiple logistic regression analysis was used to assess the relationship between scented candles exposure and respiratory and other health-related problems. RESULTS: The prevalence of scented candles usage was 65.7% (472/718) among the respondents. However, its pervasiveness was significantly higher in females than in male respondents (74.9% vs. 28.4%; p = 0.0001). Among the scented candle users, 34.8% of the respondents used the scented candles more than 4 times a month and 40.2% of the respondents lit the scented candles for 20-40 min. A total of 117 (24.8%) respondents reported health-related problem and the top three health problems were headache 72 (15.2%), shortness of breath 42 (8.9%) and cough 37 (7.8%). The scented candle usage 5-6 times a week showed significantly lower wheezing (OR = 0.10, 95%CI 0.02-0.54, p = 0.008). The duration of more than 60 min of scented candle exposure showed higher occurrence of headache 1.42 times (95% CI = 0.68-2.96), sneezing 1.29 times (95% CI = 0.42-4.00) and wheezing 1.23 times (95% CI = 0.48-3.13), though the association was not significant. CONCLUSION: The results show that scented candle usage is more prevalent among female university students in Saudi Arabia. The common health-related problems associated with scented candle exposure were headache, shortness of breath and coughing.

Properties and Applications of Geopolymer Composites: A Review Study of Mechanical and Microstructural Properties.

Portland cement (PC) is considered the most energy-intensive building material and contributes to around 10% of global warming. It exacerbates global warming and climate change, which have a harmful environmental impact. Efforts are being made to produce sustainable and green concrete as an alternative to PC concrete. As a result, developing a more sustainable strategy and eco-friendly materials to replace ordinary concrete has become critical. Many studies on geopolymer concrete, which has equal or even superior durability and strength compared to traditional concrete, have been conducted for this purpose by many researchers. Geopolymer concrete (GPC) has been developed as a possible new construction material for replacing conventional concrete, offering a clean technological choice for long-term growth. Over the last few decades, geopolymer concrete has been investigated as a feasible green construction material that can reduce CO2 emissions because it uses industrial wastes as raw materials. GPC has proven effective for structural applications due to its workability and analogical strength compared to standard cement concrete. This review article discusses the engineering properties and microstructure of GPC and shows its merits in construction applications with some guidelines and suggestions recommended for both the academic community and the industrial sector. This literature review also demonstrates that the mechanical properties of GPC are comparable and even sometimes better than those of PC concrete. Moreover, the microstructure of GPC is significantly different from that of PC concrete microstructure and can be affected by many factors.

Adsorption of Indigo Carmine Dye by Acacia nilotica sawdust activated carbon in fixed bed column.

A continuous mode fixed-bed up-flow column adsorption analysis was conducted utilizing Acacia nilotica sawdust activated carbon (ASAC) as an adsorbent for the adsorption treatment of toxic Indigo Carmine Dye (ICD). The effect on the adsorption characteristics of ASAC of the influent ICD concentration, flow rate, and column bed depth has been investigated. According to the column study, the highest efficiency of ICD removal was approximately 79.01% at a preliminary concentration of 100 mg/L with a flow rate of 250 mL/h at a bed depth of 30 cm and adsorption power of 24.67 mg/g. The experimental work confirmed the dependency of break-through curves on dye concentration and flow rate for a given bed depth. Kinetic models were implemented by Thomas, Yoon-Nelson, and Bed-depth-service-time analysis along with error analysis to interpret experimental data for bed depth of 15 cm and 30 cm, ICD concentration of 100 mg/L and 200 mg/L and flow rate of 250 mL/h, and 500 mL/h. The analysis predicted the breakthrough curves using a regression basin. It indicated that all three models were comparable for the entire break-through curve depiction. The characteristic parameters determined by process design and error analysis revealed that the Thomas model was better followed by the BDST and Yoon-Nelson models in relating the procedure of ICD adsorption onto ASAC. B-E-T surface area and B-E-T pore volume of ASAC were 737.76 m2/g and 0.2583 cm3/g, respectively. S-E-M and X-R-D analysis reveal the micro-porous and amorphous nature of ASAC. F-T-I-R spectroscope indicate distinctive functional assemblies like -OH group, C-H bond, C-C bond, C-OH, and C-O groups on ASAC. It could be computed that the ASAC can be used efficiently as an alternative option for industrial wastewater treatment.

Fabrication of alginate@silver nanoparticles (Alg@AgNPs) bionanocomposite for the sequestration of crystal violet dye from aqueous solution.

In the present study, alginate@silver nanoparticles (Alg@AgNPs) bionanocomposite has been fabricated successfully and further explored for the removal of crystal violet (CV) dye from the aqueous solution. The surface morphology of the (Alg@AgNPs) bionanocomposite was characterized by various modern analytical techniques such as SEM-EDX, TEM, FTIR and XRD. The maximum adsorption was observed at optimum condition of (pH 7, adsorbent dose 0.01 g, equilibrium time 240 min and initial concentration 20 mg L-1). The maximum monolayer adsorption capacity was found to be 186.93 mg g-1 at 30 °C. The experimental data were further validated by various isotherm models and on the basis of highest correlation coefficient (R2, 0.99), Langmuir model was found to be best fitted model. Pseudo-second order kinetic model obeyed best for the experimental data with a highest correlation coefficient (R2, 0.99) at all studied temperature. In thermodynamic studies, the positive value of enthalpy change (∆H0) and entropy change (∆S0) confirmed the process to be endothermic and spontaneous in nature. Desorption studies shows that 83 % of the adsorbed CV can be desorbed in first cycle and can be regenerated up to 4th cycle effectively with 0.1 M HCl. Therefore, (Alg@AgNPs) bionanocomposite could be harnessed as a potential adsorbent for the removal of hazardous CV dye from the waste water.

In vitro maturation and in vivo stability of bioprinted human nasal cartilage.

The removal of skin cancer lesions on the nose often results in the loss of nasal cartilage. The cartilage loss is either surgically replaced with autologous cartilage or synthetic grafts. However, these replacement options come with donor-site morbidity and resorption issues. 3-dimensional (3D) bioprinting technology offers the opportunity to engineer anatomical-shaped autologous nasal cartilage grafts. The 3D bioprinted cartilage grafts need to embody a mechanically competent extracellular matrix (ECM) to allow for surgical suturing and resistance to contraction during scar tissue formation. We investigated the effect of culture period on ECM formation and mechanical properties of 3D bioprinted constructs of human nasal chondrocytes (hNC)-laden type I collagen hydrogel in vitro and in vivo. Tissue-engineered nasal cartilage constructs developed from hNC culture in clinically approved collagen type I and type III semi-permeable membrane scaffold served as control. The resulting 3D bioprinted engineered nasal cartilage constructs were comparable or better than the controls both in vitro and in vivo. This study demonstrates that 3D bioprinted constructs of engineered nasal cartilage are feasible options in nasal cartilage reconstructive surgeries.

Experimental Evaluation of Industrial Mushroom Waste Substrate Using Hybrid Mechanism of Vermicomposting and Effective Microorganisms.

Mushroom waste substrates are highly resistant lignocellulosic wastes that are commercially produced by industries after harvesting. These wastes produce large environmental challenges regarding disposal and, thus, require treatment facilities. In the present article, the effect of Eisenia-fetida-based vermicomposting and an effective microorganism solution on the mushroom waste substrate were investigated using four different composting mixtures: mushroom waste [MW] substrate composting with effective microorganisms [MW+EM], raw mushroom waste [RWM] substrate composting with effective microorganisms [RMW+EM], mushroom waste substrate composting with vermicomposting and effective microorganisms [MW+V+EM], and raw mushroom waste substrate composting with vermicomposting and effective microorganisms [RWM+V+EM]. This article discusses the structural and physiochemical changes at four samples for 45 days (almost six weeks) of composting. The physical and chemical parameters were monitored during composting and provided information on the duration of the process. The results indicated pH (7.2~8), NPK value (0.9~1.8), and C:N ratio <14, and heavy metals exhibited a decreasing trend in later stages for all sets of compost materials and showed the maturity level. FTIR spectra revealed that all four samples included peaks for the -OH (hydroxy group) ranging from 3780 to 3500 cm−1 and a ridge indicating the C=C (alkenyl bond) ranging from 1650 to 1620 cm−1 in compost. The X-ray diffraction spectrum clearly shows how earthworms and microbes break down molecules into cellulose compounds, and the average crystallinity size using Scherrer's equation was found to be between 69.82 and 93.13 nm. Based on the experimental analysis, [RWM+V+EM] accelerated the breakdown of organic matter and showed improvement compared with other composts in compostable materials, thus, emphasizing the critical nature of long-term mushroom waste management and treatment.

Early Determinants of Mortality in Hospitalized COVID-19 Patients in the Eastern Province of Saudi Arabia.

PURPOSE: This study investigated the clinical determinants of mortality in hospitalized patients infected with COVID-19. PATIENTS AND METHODS: A retrospective multicenter large cohort of COVID-19 patients hospitalized between March 2020 and February 2021. We included patients admitted with a confirmed COVID-19 infection with positive COVID-19 through real-time polymerase chain reaction (RT-PCR). SPSS version 25.0 (Armonk, NY: IBM Corp.) was used to analyze the data. RESULTS: Among the study participants (n = 1444), the mean age of the population was 49.22±17.69 years, of which 63.9% were males (n = 924). Overall, the mean age for non-survivors was 55.65 ±16.41 years and the length of ICU stay was 13.95 ±12.4 years. The most common comorbidity among the study subjects was hypertension (HTN) (32.7%), followed by cardiovascular disease (CVD) (10.7%). Patients who were mechanically ventilated (MV) had higher mortality than those who did not require MV (p < 0.001). CONCLUSION: Our study concluded that old age, the presence of underlying cardiovascular conditions, an abnormal WBC count (leukopenia or leukocytosis), and abnormal blood urea nitrogen (BUN) levels are among the independent predictors of mortality in the Saudi population. These findings may guide health care providers to manage COVID-19 patients more effectively with better outcomes.

Hesitancy towards the COVID-19 vaccine among health care practitioners in the Kingdom of Saudi Arabia: a cross-sectional study.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic is a major public health crisis worldwide. In less than 12 months since the World Health Organization declared the outbreak, several different COVID-19 vaccines have been approved and deployed mostly in developed countries since January 2021. However, hesitancy to accept the newly developed vaccines is a well-known public health challenge that needs to be addressed. The aim of this study was to measure willingness and hesitancy toward COVID-19 vaccines among health care practitioners' (HCPs) in Saudi Arabia.   Methods: A cross-sectional study using an online self-reported survey was conducted among HCPs in Saudi Arabia between April 4th to April 25th 2021 using snowball sampling. Multivariate logistic regression was employed to identify the possible factors affecting HCPs' willingness and hesitancy to receive COVID-19 vaccines.   Results: Out of 776 participants who started the survey, 505 (65%) completed it and were included in the results. Among all HCPs, 47 (9.3%) either said "no" to receive the vaccine [20 (4%)] or were hesitant to receive it [27 (5.3%)]. Of the total number of the HCPs, 376 (74.5%) already received the COVID-19 vaccine, and 48 (9.50%) were registered to receive it. The main reason of agreement to receive the COVID-19 vaccine was "wanting to protect self and others from getting the infection" (24%).   Conclusion: Our findings have shown that hesitancy toward receiving COVID-19 vaccines among HCPs in Saudi Arabia is limited and therefore may not be a serious issue. The outcomes of this study may help to understand factors that lead to vaccine hesitancy in Saudi Arabia and help public health authorities to design targeted health education interventions aiming to increase uptake of these vaccines.

Perception on Online Teaching and Learning Among Health Sciences Students in Higher Education Institutions during the COVID-19 Lockdown - Ways to Improve Teaching and Learning in Saudi Colleges and Universities.

Background: Online learning or E-learning are approaches to broadcasting teaching by the means of internet technology and software applications. Kingdom of Saudi Arabia is likewise embarking on the rapid growth in online education. The purpose of this study is to investigate the student's perceptions regarding online teaching and learning during COVID 19. Methods: An online computer-based cross-sectional study was conducted between May and June 2020. A pre-validated questionnaire was used and administrated to health sciences students studying at Dammam Universities through online software QuestionPro. Results: Out of total 281, 68% of the participants were females (n=188) while 31.9% (n=88) were male students with an average age of 23.1(4.5) years. Overall, 176 (62%) of the students expressed their satisfaction with online learning. Conclusion: Findings will help academicians to identify strengths, areas of improvement, and encourage faculty to think deeply to restructure course learning objectives, teaching techniques to engage students and improve learning process.

Shrinkage Study and Strength Aspects of Concrete with Foundry Sand and Coconut Shell as a Partial Replacement for Coarse and Fine Aggregate.

The demand for natural aggregates (river sand) is increasing day by day, leading to the destruction of the environment, a burden that will be passed on to young people. Further, wastes from various industries are being dumped in landfills, which poses serious environmental problems. In order to ensure sustainability, both the issues mentioned above can be solved by utilizing industrial waste as aggregate replacement in the concrete construction industry. This research is done to find out the results using two substances viz., waste foundry sand (WFS) and coconut shell (CS) substitute for river sand and coarse aggregate. Many researchers have found the maximum benefits of substituted substances used in cement, which has material consistency. This current observation explores these strong waste properties of waste-infused concrete and cement, which experience shrinkage from drying out. The replacement levels for waste foundry sand were varied, between 10%, 20%, and 30%, and for CS, it was 10% and 20%. The experimental outcomes are evident for the strength, which increases by using WFS, whereas the strength decreases by increasing the CS level. The concrete that experiences shrinkage from drying out is included in the waste material, showing a higher magnitude of drying shrinkage than conventional concrete.

Influence of Heat Treatment and Reinforcements on Tensile Characteristics of Aluminium AA 5083/Silicon Carbide/Fly Ash Composites.

The effect of reinforcements and thermal exposure on the tensile properties of aluminium AA 5083-silicon carbide (SiC)-fly ash composites were studied in the present work. The specimens were fabricated with varying wt.% of fly ash and silicon carbide and subjected to T6 thermal cycle conditions to enhance the properties through "precipitation hardening". The analyses of the microstructure and the elemental distribution were carried out using scanning electron microscopic (SEM) images and energy dispersive spectroscopy (EDS). The composite specimens thus subjected to thermal treatment exhibit uniform distribution of the reinforcements, and the energy dispersive spectrum exhibit the presence of Al, Si, Mg, O elements, along with the traces of few other elements. The effects of reinforcements and heat treatment on the tensile properties were investigated through a set of scientifically designed experimental trials. From the investigations, it is observed that the tensile and yield strength increases up to 160 °C, beyond which there is a slight reduction in the tensile and yield strength with an increase in temperature (i.e., 200 °C). Additionally, the % elongation of the composites decreases substantially with the inclusion of the reinforcements and thermal exposure, leading to an increase in stiffness and elastic modulus of the specimens. The improvement in the strength and elastic modulus of the composites is attributed to a number of factors, i.e., the diffusion mechanism, composition of the reinforcements, heat treatment temperatures, and grain refinement. Further, the optimisation studies and ANN modelling validated the experimental outcomes and provided the training models for the test data with the correlation coefficients for interpolating the results for different sets of parameters, thereby facilitating the fabrication of hybrid composite components for various automotive and aerospace applications.