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Transcribing quantum effects from lower to higher dimensions is a complex yet intriguing area of research. Coulomb blockade (CB), a fundamental quantum phenomenon, is commonly observed in low-dimensional materials like quantum dots (QDs) at extremely low temperatures. This behavior shows promise for the development of high-performance memory and thermoelectric devices. However, when transitioning to larger dimensions, such as arrays at room temperature, the CB effect is hindered by thermal fluctuations and structural inconsistencies. This study presents a thorough examination of electron transport through PbS QDs using a blend of experimental and theoretical methods. By creating a sizable parallel array of QDs immobilized on self-assembled monolayers (SAMs) and employing single-layer graphene (SLG) as the top electrode, we were able to maintain the CB effect at room temperature on a device scale. Additionally, a device with a top gate structure was designed to precisely regulate the energetic position of quantum states in relation to the Fermi level of the electrode. By utilizing ultra-small QDs (typically 2 nm in size), we successfully sustained the CB effect at room temperature. To investigate the impact of structural uncertainties, we combined density-functional theory and quantum transport theory to comprehensively analyze the quantum transport properties of QDs bound with SAMs across various facets. This enabled us to establish a correlation between these structural variations and the experimental data distribution. [ABSTRACT FROM AUTHOR]

Purpose: Healthcare practitioners in Saudi Arabia sometimes experience workplace bullying (WPB). However, more research on this issue must be carried out in the country. This study aimed to investigate the prevalence of WPB and how individual factors among nurses contribute to different experiences of WPB in clinical settings. Methods: This cross-sectional quantitative study occurred among registered nurses in Riyadh, Saudi Arabia. A self-administered questionnaire was used, and nurses filled it out via a Google survey that included sociodemographic details such as age, gender, education, and the WBS to gauge the prevalence of workplace bullying in hospital settings. Results: Of 416 nurses, 58.7% were aged between 31 and 40, and 76.9% were women. The prevalence of WPB was found to be 54.8%. WPB was higher among middle-aged nurses, men, charge/managerial nurses, nurses with higher education, those with 3 to 6 years of experience, and those working in specialty units. Conclusions: More than half of the nurses had experienced WPB at some point. Middle-aged nurses, especially men with higher education and more experience in specialty units, were the most common victims of WPB compared to other registered nurses. [ABSTRACT FROM AUTHOR]

(1) Background: Food allergy (FA) is an immune-mediated hypersensitivity to foods, significantly contributing to childhood morbidity and mortality. This study aimed to assess the prevalence, characteristics, and influencing factors of parent-reported FAs among children in Saudi Arabia. (2) Methods: This cross-sectional study utilized a validated parental questionnaire distributed across all regions of Saudi Arabia. Data from 2130 participants were collected and analyzed using SPSS v. 26 and Prism software v. 10.3.0. (3) Results: Parent-reported FA prevalence was 15.2%. Egg was the most common allergen (6.2%), followed by tree nuts (4.1%), peanuts (4.0%), milk (3.8%), and sesame (3.2%). Significant geographical variations were observed, with the western region having the highest burden (p < 0.001). Older children had higher rates of shellfish and fish allergies. Parental allergies and co-existing asthma/drug allergies were positively associated with childhood FAs. (4) Conclusions: This study highlights a substantial burden of parent-reported FAs in Saudi Arabia, with regional variations in food allergen distribution. Parental allergies and co-existing allergic conditions may influence FA risk. [ABSTRACT FROM AUTHOR]

This study aims to prepare new nanocomposites consisting of Cr2O3/CaCO3 as a catalyst for improved hydrogen production from NaBH4 methanolysis. The new nanocomposite possesses nanoparticles with the compositional formula Cr2−xCaxO3 (x = 0, 0.3, and 0.6). These samples were prepared using the sol-gel method, which comprises gelatin fuel. The structure of the new composites was studied using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, environmental scanning electron microscopy (ESEM), and X-ray spectroscopy (XPS). The XRD data showed the rhombohedral crystallinity of the studied samples, and the average crystal size was 25 nm. The FTIR measurements represented the absorption bands of Cr2O3 and CaO. The ESEM micrographs of the Cr2O3 showed the spherical shape of the Cr2O3 nanoparticles. The XPS measurements proved the desired oxidation states of the Cr2−xCaxO3 nanoparticles. The optical band gap of Cr2O3 is 3.0 eV, and calcium doping causes a reduction to 2.5 and 1.3 eV at 15.0 and 30.0% doping ratios. The methanolysis of NaBH4 involved accelerated H2 production when using Cr2−xCaxO3 as a catalyst. Furthermore, the Cr1.7Ca0.3O3 catalyst had the highest hydrogen generation rate, with a value of 12,750 mL/g/min. [ABSTRACT FROM AUTHOR]

β-thalassemia is a genetic disorder affecting chromosome 16, inherited from one or both parents. In spite of the improved treatment of the hematological disorder and its complications, β-thalassemic patients still exhibit an imbalance in bone mineral turnover, resulting in diminished bone mineral density (BMD), more evident in the lumbar spine. The purpose of this study was to investigate the association between genetic polymorphism of the PPAR-γ gene and the presence of osteopenia or osteoporosis in children with β-thalassemia. This case–control study was conducted on 50 children with β-thalassemia from the pediatric hematology unit of Beni-Suef University Hospital, including 50 healthy children as the control group. The age range was 8 to 18 years. Samples of patients and control subjects were analyzed for the presence of polymorphisms of the PPAR-γ gene and other blood labs. An assay of BMD measure using dual-energy X-ray absorptiometry (DXA) was performed to investigate osteopenia or osteoporosis. Statistical analysis was used to investigate the relationship between the risk of osteopenia or osteoporosis and the presence of PPAR-γ Pro12Ala gene polymorphism. Eighteen (eleven males and seven females) of fifty patients (representing 36% of the patients group) have osteopenia with low bone mineral density (Z-score is −1 or less than 1). There was no statistically significant difference between BMD measurements in males and females. By comparing the frequency of 12 Ala gene polymorphisms between the patient group and the control group, we found that no statistically significant difference was detected. The BMD values were not significantly different between the groups of PPAR-γ Pro12Ala gene polymorphism. In conclusion, decreased BMD levels are frequent in β-thalassemia patients. PPAR-γ Pro12Ala gene polymorphism is not common in Egyptian patients with β-thalassemia. No significant relationship was found between the PPAR-γ Pro12Ala gene polymorphism and low BMD levels or osteopenia in Egyptian β-thalassemia patients. However, further studies on a larger population of Egyptian patients are needed to confirm this finding. [ABSTRACT FROM AUTHOR]

Recent advancements in experimental approaches have made it possible to synthesize silver (Ag5) atomic quantum clusters (AQCs), which have shown a great potential in photocatalysis. This study employs the generalized gradient approximation (GGA) density functional theory (DFT) to explore the adsorption of CO2, CH4, and H2O molecules on the Ag5 AQC. Our investigations focus on the structural and electronic properties of the molecules in Ag5 AQC systems. This involves adsorption energy simulations, charge transfer, charge density difference, and the density of states for the modelled systems. Our simulations suggest that CH4 and H2O molecules exhibit higher adsorption energies on the Ag5 AQC compared to CO2 molecules. Remarkably, the presence of CH4 molecule leads to a significant deformation in the Ag5 AQC structure. The structure reforms from a bipyramidal to trapezoidal shape. This study also reveals that the Ag5 AQC donates electrons to CO2 and CH4 molecules, resulting in an oxidation state. In contrast, gaining charges from H2O molecules results in a reduced state. We believe the proposed predictions provide valuable insights for future experimental investigations of the interaction behaviour between carbon dioxide, methane, water molecules, and Ag5 sub-nanometre clusters. [ABSTRACT FROM AUTHOR]