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Single-atom catalysts have the advantage of high chemical efficiency, which requires atomic-scale control during catalyst formation. In order to address this challenge, this work explores the synthesis of single-atom platinum (SA-Pt) catalysts using atomic-layer deposition (ALD) on vertical graphene (VG), in which a large number of graphene edges serve as energetically favorable nucleation sites for SA-Pt, as predicted by density functional theory calculations. Interestingly, SA-Pt has been achieved on VGs at low ALD cycle numbers of up to 60. With a further increase in the number of ALD cycles, an increasing number of Pt clusters with diameters <2 nm and Pt nanoparticles (NPs) with diameters >2 nm become dominant (nano-Pt @VG). This is in contrast to the observation of predominantly nano-Pt on other carbon nanostructures, such as carbon nanotubes and monolayer graphene, under the same ALD growth conditions, indicating that the edge states on VG indeed play a critical role in facilitating the formation of SA-Pt. Profound differences are revealed in a comparative study on H2 sensing. SA-Pt exhibits both a higher sensitivity and faster response than its nano-Pt counterpart by more than an order of magnitude, illustrating the high catalytic efficiency of SA-Pt and its potential for gas sensing and a variety of other catalytic applications. [ABSTRACT FROM AUTHOR]

Oleuropein (OLP) is a naturally occurring phenolic compound in olive plant with antioxidant and anti-inflammatory potential and can possibly be used in treating pancreatic injuries. This investigation aimed to follow the molecular mechanism behind the potential therapeutic effect of OLP against pancreatic injury persuaded by ischemia–reperfusion (I/R). Pancreatic I/R injury was induced by splenic artery occlusion for 60 min followed by reperfusion. Oral administration of OLP (10 and 20 mg/kg) for 2 days significantly alleviated I/R-persuaded oxidative damage and inflammatory responses in pancreatic tissue as indicated by the decreased malondialdehyde (MDA) content and increased glutathione peroxidase (GPx) activity, accompanied by the suppression of myeloperoxidase (MPO) activity and reduced levels of interleukin-1beta (IL-1β), nuclear factor kappa B (NF-κB), and tumor necrosis factor alpha (TNF-α) in pancreatic tissues. Furthermore, OLP treatment markedly restored the serum levels of amylase, trypsinogen-activated peptide (TAP), and lipase, with concurrent improvement in pancreatic histopathological alterations. Moreover, treatment with OLP regulated the pancreatic expression of inducible nitric oxide synthase (iNOS) and high-mobility group box 1 (HMGB1) relative to rats of the pancreatic IR group. Thus, OLP treatment significantly alleviates the I/R-induced pancreatic injury by inhibiting oxidative stress and inflammation in rats through downregulation of HMGB1 and its downstream NF-κB signaling pathway. [ABSTRACT FROM AUTHOR]

The current research focuses on the effect of incorporating edge-oxidized graphene oxide (EOGO) on the performance of layered cement composites cast at different times. The feature of producing flower-shaped hydrated cement products is exploited to enhance the contact surface of two different cement composites. In the current study, the interval time of casting cement composites is the crucial parameter investigated. Consequently, a layer of cement paste with EOGO is cast above a layer of cement mortar where the amount of EOGO of 0.10% by the cement weight is fixed for all mixtures. Also, four different interval times based on cement setting time are considered, namely immediately, 6 h, 12 h, and 1 day. Similar mixtures are prepared but without adding EOGO for comparison purposes. The results show that EOGO is capable of enhancing the contact surface of layered cement composites by strengthening the split strength of two different layers (between 12 and 29%). Moreover, casting the paste layer containing EOGO after 6 h of mortar layer seems to be the optimum interval time among others by improving compressive strength (by 29%) and residual strength (by 34%) and not affecting flexural strength and porosity percentage. [ABSTRACT FROM AUTHOR]

Scrap tires have become one of the most serious environmental issues worldwide in recent years. Exploiting this scrap has caught the attention of researchers in their efforts to conserve the environment. From a structural engineering materials perspective, a partial fine aggregate in cement mortar can be replaced by crumb rubber produced from scrap tires. This research mainly emphasizes the role of adding 0.1% edge-oxidized graphene oxide EOGO (by the weight of cement) in enhancing the properties of cement mortars containing 5%, 10%, and 15% of crumb rubber (by sand replacement). Cube and prism specimens were employed to investigate compressive and flexural strengths at 7- and 28-day curing ages. A porosity test was also conducted after 28 days of curing. In addition, a scanning electron microscopy (SEM) test was performed to investigate the effect of incorporating EOGO on the interfacial transition zone (ITZ). Results showed an enhancement of the mechanical properties of cement mortar, including compressive and flexural strengths, with the inclusion of EOGO in the mixes. The findings demonstrated that adding EOGO can improve the mechanical properties of mixes containing crumb rubber particles. Specifically, the mortar mix with 0.1% EOGO and 5% crumb rubber exhibited better performance compared with the virgin mix without rubber particles. Therefore, crumb rubber is viable for use as a sand replacement when EOGO is included. [ABSTRACT FROM AUTHOR]

The average content of reclaimed asphalt pavement (RAP) materials in asphalt mixtures for new pavements is around 22% in the current paving practices in the United States. Increasing this content has significant economic and environmental benefits. This study explored the approach of producing asphalt mixtures with 100% RAP materials by adding a small percentage of epoxy asphalt. Specimens of 100% RAP mixtures with low contents of epoxy asphalt were fabricated and evaluated in the laboratory for their properties related to pavement performance, including Marshall stability and flow, indirect tensile strength, resistance to moisture damage, resistance to fatigue damage, and fracture resistance. The results showed that the specimens made of 100% RAP materials selected in this study without a new binder or rejuvenator had low workability and high Marshall stability and indirect tensile strength but poor resistance to moisture damage and fatigue damage. A low percentage (0.5 to 2%) of epoxy asphalt significantly improved the resistance to moisture and fatigue damage of the 100% RAP mixture, and this improvement increased with the epoxy asphalt content. The fracture resistance of the 100% RAP mixture was also significantly improved by a low dosage of epoxy asphalt at a low temperature (8 °C), but the improvement was less significant at a moderate temperature of 25 °C. [ABSTRACT FROM AUTHOR]

A selective, facile, and highly efficient spectrophotometric approach was established for the determination of 1,4-dioxane in drinking water quantitatively. This approach depends on the reaction selectively of 1,4-dioxane with 1-Amino-2-naphthol-4-sulphonic acid (AHSA) to give an instantly complex measured at 340 nm. The maximum spectra development with high intensity of dioxane-AHSA complex was obtained at 15 min. Variable parameters that affecting the dioxane-AHSA efficacy were estimated and optimised. Under optimal conditions, the dioxane-AHSA complex obeyed Beer's law within the range of 0.5–15 mg/L of 1,4-dioxane with a regression factor of 0.996 (n = 5) and a detection limit of 16 µg/L. The results of precision and accuracy within-day were ≤2.0% in terms of relative standard deviation (RSD%), which confirmed the reproducibility of the analytical performance. The proposed method was applied successfully in the simultaneous assessment of 1,4-dioxane in an aqueous solution. The accuracy and reliability of the developed approach recommended being applied in all quality control of water companies without the use of sophisticated instrumentation and procedure. [ABSTRACT FROM AUTHOR]

The crustal structure beneath the United Arab Emirates (UAE) is still relatively unknown. Here, we use regional gravity data to constrain the subsurface density distribution and structure of the crust of the UAE by applying diverse gravity derivatives methods such as horizontal derivative (HDR), analytic signal (AS), and tilt angle (TA) to analyze the subsurface structure and perform three-dimensional (3D) gravity inversion for imaging crustal structure from the surface down to 35 km depth. The results are compared with known geological regional structures and the location of the petroleum fields.

Study Design: Cross-sectional Objective: This study evaluated the various reasons and causes for odontophobia among Saudi parents accompanying pediatric patients at King Khalid University, Saudi Arabia. Methods: A cross-sectional study was carried out on a total number of 300 parents (Male=150; Female=150) who participated in the study with age ranges from 30- to 55-year-old to know the various reasons and causes for odontophobia among Saudi parents accompanying pediatric patients attending dental clinic in college of dentistry, King Khalid University, Abha. The Questionnaire was given to Saudi parents accompanying pediatric patients attending dental clinics and data was collected from them. The data were entered and analyzed using the Statistical Package for the Social Sciences (SPSS 20). A P-value of less than 0.05 was considered to be statistically significant. Results: The majority of participants, 189(63%) were, said that they have experience of dental fear and anxiety in their lifetime period. 255(85%) agreed that they have come across one of their relatives or friends having the fear of dental treatment. Parents experienced various reasons for the cause of their dental fear, one of the major factors for dental fear they told was having the dentist remove their tooth (26%). Parents 155 (52%) stated that they visited dental clinic for treatment very often and 66(22%) visited rarely. Conclusions: Recognizing the level of fear that prevents patients from seeking dental care and understanding the occurrence of dental anxiety hold crucial importance in dental practice. While only a small percentage of subjects reported dental fear or would consider refusing dental consultations, assessing dental fear provides valuable insights for dental practitioners. However, there is a call for further research and efforts to enhance the comprehension of dental anxiety and behaviors during dental visits. [ABSTRACT FROM AUTHOR]

Study Design: Cross-sectional Objective: This study evaluated the various reasons and causes for odontophobia among Saudi parents accompanying pediatric patients at King Khalid University, Saudi Arabia. Methods: A cross-sectional study was carried out on a total number of 300 parents (Male=150; Female=150) who participated in the study with age ranges from 30- to 55-year-old to know the various reasons and causes for odontophobia among Saudi parents accompanying pediatric patients attending dental clinic in college of dentistry, King Khalid University, Abha. The Questionnaire was given to Saudi parents accompanying pediatric patients attending dental clinics and data was collected from them. The data were entered and analyzed using the Statistical Package for the Social Sciences (SPSS 20). A P-value of less than 0.05 was considered to be statistically significant. Results: The majority of participants, 189(63%) were, said that they have experience of dental fear and anxiety in their lifetime period. 255(85%) agreed that they have come across one of their relatives or friends having the fear of dental treatment. Parents experienced various reasons for the cause of their dental fear, one of the major factors for dental fear they told was having the dentist remove their tooth (26%). Parents 155 (52%) stated that they visited dental clinic for treatment very often and 66(22%) visited rarely. Conclusions: Recognizing the level of fear that prevents patients from seeking dental care and understanding the occurrence of dental anxiety hold crucial importance in dental practice. While only a small percentage of subjects reported dental fear or would consider refusing dental consultations, assessing dental fear provides valuable insights for dental practitioners. However, there is a call for further research and efforts to enhance the comprehension of dental anxiety and behaviors during dental visits. [ABSTRACT FROM AUTHOR]

Steel slag waste produced by the steel industry accumulates in open areas or is disposed of in landfills, causing harm to the environment and human health. Valorizing steel slag through comprehensive data analysis is imperative and could add value to the product with respect to energy conversion and storage applications. This study investigated the morphological, structural, and optical characteristics of a thermally annealed steel slag composite generated from iron and steel factories. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), Raman spectroscopy, and UV–visible spectrophotometry were subsequently used to evaluate the impact of thermal treatment on the morphology, structure, elemental composition, and optical properties. It was found that the pre-treated slag composites contained a variety of irregular grain sizes and microscale fragments, primarily composed of C (18.55%), O (50.85%), and Fe (29.41%), with lower amounts of Mg (0.31%), Si (0.44%), and Ca (0.44%), indicating the natural formation of a disordered iron composite. Thermal treatment at different temperatures (300 °C, 600 °C, and 900 °C) increased the grain density and clustering, resulting in denser two-dimensional microstructures at 900 °C. Additionally, XRD and Raman analyses of both untreated and thermally treated slag composites revealed the presence of a disordered iron oxide composite, including (Fe3O4), hematite (α-Fe2O3), and maghemite (γ-Fe2O3) phases. A significant increase in optical absorbance was also observed after annealing at 600 °C, highlighting the successful optimization of the elemental composition of the slag composite. A band gap energy of approximately 2.2 eV was obtained from this optimization at 600 °C. The optical conductivity of the composite reached 2.1 × 106 S−1 at 600 °C, which indicates an enhancement in charge transfer among the optimized chemical elements in the waste composite. These findings suggest an optimization method for novel composites derived from steel slag waste, indicating its potential as a low-cost material for energy storage systems (batteries, supercapacitors, and fuel cells) and optoelectronic devices. [ABSTRACT FROM AUTHOR]