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Abstract Developing a potent antiviral agent to combat Coronavirus Disease-19 (COVID-19) is of critical importance as we may be at risk of the emergence of new virus strains or another pandemic recurrence. The interaction between the SARS-CoV-2 spike protein and Angiotensin Converting Enzyme 2 (ACE2) is the main protein-protein interaction (PPI) implicated in the virus entry into the host cells. Spike-ACE2 PPI represents a major target for drug intervention. We have repurposed a previously described protein-protein interaction detection method to be utilized as a drug screening assay. The assay was standardized using Chitosan nanoparticles (CNPs) as the drug and SARS-CoV-2 spike-ACE2 interaction as the PPI model. The assay was then used to screen four natural bioactive compounds: Curcumin (Cur), Gallic acid (GA), Quercetin (Q), and Silymarin (Sil), and their cytotoxicity was evaluated in vitro. Production of the spike protein and the evaluation of its activity in comparison to a standard commercial protein was part of our work as well. Here we describe a novel simple immunofluorescent screening assay to identify potential SARS-CoV-2 inhibitors that could assess the inhibitory effect of any ligand against any PPI. Graphical Abstract

Abstract Background This study aimed to develop a new formula to easily estimate the vertical dimension of occlusion (VDO) by using the distance between the mental foramen on a panoramic radiograph. Subjects and methods A total of 508 dentulous subjects were selected from outpatient dental clinics at the College of Dental Medicine, Al-Azhar University. The vertical dimension of the occlusion was measured using a single calibrated calliper. For each subject, a digital panoramic radiograph was taken with fixed exposure parameters. The intermental foramina distance (IMFD) was measured. The data were collected and then analysed using the IBM SPSS version 20.0 software package. (Armonk, NY: IBM Corp.). Linear regression was used to determine the relationship between the intermental foramina distance (IMFD) and the vertical dimension at occlusion (VDO). Results Pearson’s correlation analysis revealed that there was a strong correlation between the intermental foramina distance (IMFD) and the VDO. Thus, a novel formula was developed for determining the VDO using panoramic radiography. Conclusion The novel formula developed herein facilitated the determination of the VDO among prosthetic rehabilitation for subjects who lost vertical dimension due to loss of posterior teeth or severe wear of natural posterior teeth. Further studies are needed to determine the clinical applicability of the derived formulae for edentulous subjects.

Background This study aimed to compare the perceived masticatory ability (PrMA) in completely edentulous patients (EDPs) with thermoplastic conventional complete dentures (CDs) versus single implant-retained mandibular overdentures. Methods The current study was conducted in the outpatient Prosthodontic Clinic, Faculty of Dental Medicine, Al-Azhar University, Cairo, Egypt. PrMA was evaluated in 45 completely edentulous patients (46% males, mean age 50.4 ± 4.7 years). Each patient received a thermoplastic PMMA complete denture (Polyan IC TM Bredent GmbH & Co.KG, Germany). The PrMA was evaluated at one-month and six-month intervals of denture use. An immediate loading single implant was placed into the mid-symphyseal for each patient, and the denture was adjusted. Subsequently, the PrMA was reevaluated after one month and six months. The data were collected and statistically analyzed using the SPSS@V25 to assess the changes in PrMA. Results The PrMA demonstrated improvement after six months of thermoplastic conventional denture use. However, this improvement was not statistically significant (p = 0.405). In addition, the PrMA showed a substantial increase following a single implant placement at one and six months (p

A survey of the nematophagous mycobiota biodiversity of 82 soil and leaf-litter samples in the Sultanate of Oman yielded ten species of nematode trapping fungi belonging to three genera. The species are: Arthrobotrys eudermata, A. thaumasia, A. musiformis, A. oligospora, A. oligospora var. oligospora, A. oudemansii, A. multiformis, A. javanica, Drechslerella brochopaga and Gamsylella geophyropaga. This is the first record of these species in Oman. Arthobotrys multiformis represents the second record of this species worldwide. A systematic study showed that A. oudemansii, A. multiformis and A. javanica were morphologically more variable than was so far known. In four days, A. oligospora, A. thaumasia, D. brochopaga and A. eudermata trapped all nematodes added to the Petri dishes (Panagrellus redivivus, 100 specimens per dish). No significant differences were found in the trapping efficiency among the species tested.

This study explores the adsorption efficiency of biochar derived from palm trees and Ficus nitida for the removal of various contaminants, including Cu(II), Pb(II), iodine, and chlorpyrifos from aqueous solutions. Biochar was prepared using a two-step pyrolysis process for date palm biochar and single-step pyrolysis for Ficus nitida biochar. Characterization techniques such as SEM, EDX, and FTIR revealed a significant surface area and a variety of functional groups in both types of biochar, essential for effective adsorption. The date palm biochar exhibited superior adsorption capacities for Cu(II) and Pb(II) ions, achieving efficiencies up to 99.9% and 100%, respectively, due to its high content of oxygen-containing functional groups that facilitated strong complexation and ion exchange mechanisms. Conversely, Ficus nitida biochar demonstrated a higher adsorption capacity for iodine, reaching 68% adsorption compared to 39.7% for date palm biochar, owing to its greater surface area and microporosity. In the case of chlorpyrifos, Ficus nitida biochar again outperformed date palm biochar, achieving a maximum adsorption efficiency of 87% after 24 h of incubation, compared to 50.8% for date palm biochar. The study also examines the effect of incubation time on adsorption efficiency, showing that the adsorption of chlorpyrifos by date palm biochar increased significantly with time, reaching a maximum of 62.9% after 48 h, with no further improvement beyond 12 h. These results highlight the importance of biochar characteristics, such as surface area, pore structure, and functional groups, in determining adsorption efficiency. The findings suggest that optimizing pyrolysis conditions and surface modifications could further enhance the performance of biochar as a cost-effective and sustainable solution for water purification and environmental remediation.

This study aims to increase the effectiveness of photovoltaic pumping systems. A practical installation and cost-effective design are suggested. This paper examines the nonlinear behaviour of photovoltaic generators from a distinct perspective; where it repeatedly transitions between a constant current and a constant voltage source and shows how this affects the behaviour of the induction motors. A Fractional-order Neural Network (FONN) is suggested to forecast the harvested solar-energy. The results showed that FONN improved forecasting accuracy by effectively capturing the nonlinear behaviour of PV panels. A Fractional Order MPPT (FO-MPPT) control augmented with Gray Wolf, Anti-lion, and Whale metaheuristic optimizers is proposed and shows capacity to maximize the harvest power for the PV-driven Induction Motor-Pump. The proposed FO-MPPT is compared to conventional techniques using several performance metrics. According to the comparison study, the optimized FO-MPPT enhances the standard MPPT and shows superiority in managing the nonlinear and unpredictable dynamical loads.

Suaeda vermiculata Forssk. ex JF Gmel. (SV), a traditional known plant, has shown in vitro cytotoxic activity against HepG2 and HepG-2/ADR (doxorubicin-resistant cells) liver cell carcinoma cell lines, as well as hepatoprotection against paracetamol and carbon tetrachloride (CCl4)-induced liver injury. The current study evaluated the protective effect of SV, administered against N-diethylnitrosamine (NDEA)-induced HCC in rats. The possible modulatory effect of SV on the PI3K/HIF-1α/c-MYC/iNOS pathway was investigated. Sixty male adult albino rats (200 ± 10 g) were equally classified into five groups. Group I served as a control; Group 2 (SV control group) received SV (p.o., 200 mg/kg body weight); Group 3 (NDEA-administered rats) received freshly prepared NDEA solution (100 mg/L); and Groups 4 and 5 received simultaneously, for 16 weeks, NDEA + SV extract (100 and 200 mg/kg, orally). NDEA-treated rats displayed significant increases in serum levels of AFP, CEA, PI3K, malondialdehyde (MDA), epidermal growth factor receptor (EGFR), and vascular endothelial growth factor (VEGFR), with increased liver tissue protein expression of fibrinogen concomitant and significantly decreased concentrations of antioxidant parameters (catalase (CAT), superoxide dismutase (SOD), and reduced glutathione (GSH)) in comparison to normal rats. On the flip side, AFP, CEA, PI3K, MDA, EGFR, and VEGFR serum levels were significantly reduced in rats that received NDEA with SV, both at low (SV LD) and high (SV HD) doses, accompanied by significant improvements in antioxidant parameters compared to the NDEA-treated group. Conclusions: SV possesses a significant hepatoprotective effect against NDEA-induced HCC via inhibiting the PI3K/HIF-1α/c-MYC/iNOS pathway, suggesting that SV could be a promising hepatocellular carcinoma treatment.

A precise prediction of the rolling force is critical to ensure the quality of the final product, especially in the cold rolling of thin strips. Based on this, a new mathematical model is developed to work out the rolling force when considering the roll crossing angle and work roll shifting values at speed ratios of 1.1, 1.2 and 1.3. An iterative method was used to indicate the contact area shape, from which the rolling force was automatically calculated using the Matlab™ code for the cases of work roll cross angles of 0.5° and 1°. Experimental measurements and analysis were carried out to validate the theoretical calculations. The result shows that the theoretical analysis and experimental results are in good agreement, which indicates that the developed theoretical model can predict the rolling force well with a consideration of roll crossing during the cold rolling process.

This research focuses on the study of the simulation capabilities of the lagrangian (LAG) model and Smoothed Particle Hydrodynamics (SPH) model for the orthogonal dry machining of aluminum alloy Al6061-T6. A three-dimensional finite element model was developed and verified using experimental data from the published literature. The numerical models were developed using lagrangian boundary conditions via finite element modeling in ABAQUS/Explicit 6.14. The cutting simulations were carried out at low and medium cutting speeds. Johnson–Cook material constitutive law and Johnson–Cook damage law were used in both models. The numerical methodologies are compared based on cutting forces, chip morphology, shear angle, chip separation criterion, and chip thickness. The findings of the present work show that the LAG model is good for predictions regarding cutting forces and chip morphology, while the SPH model is good for predictions regarding the shear angle and chip thickness. The difference between results generated by both models mainly occurred due to the friction coefficient. The comparative study shown here offers a guidance approach for various numerical models for appropriate parameter analysis.

This paper investigates the solution to one-dimensional fractional differential equations with two types of fractional derivative operators of orders in the range of (1,2). Two linearized schemes of the numerical method are constructed. The considered FDEs are equivalently transformed by the Riemann–Liouville integral into their integro-partial differential problems to reduce the requirement for smoothness in time. The analysis of stability and convergence is rigorously discussed. Finally, numerical experiments are described, which confirm the obtained theoretical analysis.

In this paper, the cladding of pure aluminum and a low-carbon steel alloy was performed through friction stir processing with minimal intermetallic compound formation. A 3 mm thick aluminum plate was clamped on top of a steel plate. A thick, pure copper plate was used as a backing plate. The tool pin length was adjusted to be the same as the upper plate’s thickness (3 mm) and longer than 3.2 mm. The effect of the tool pin length and the rotation speed (500–1500 rpm) on the cladding’s quality, microstructure, and the mechanical properties of the steel/aluminum interface were investigated using optical and scanning electron microscopy, a hardness test, and a peel test. The results showed that the bonding of pure aluminum and a low-carbon steel alloy can be successfully performed at a more than 500 rpm rotation speed. At a tool pin length of 3 mm and a rotation speed of 1000 rpm, sound and free-intermetallic compound–cladding interfaces were formed, while some Fel2Al5 intermetallics were formed when the rotation speed was increased to 1500 rpm. The pure copper backing plate has an essential role in eliminating or reducing the formation of intermetallic compounds in the cladding interface. When the tool pin length was increased to 3.2 mm, more steel fragments were found on the aluminum side. Moreover, with a higher rotation speed and longer tool pin length, more Fe2Al5 intermetallics were formed at the interface. Increasing the rotation speed and the pin tool length contributed to the enhancement of interface bonding. Meanwhile, the maximum tensile shear load was obtained at a rotation speed of 1500 rpm and a tool pin length of 3.2 mm. In addition, the hardness values of the interface were higher than the aluminum base metal for all the investigated samples. Decreasing the rotation speed and increasing the tool pin length can significantly increase hardness measurements. The average hardness increases from 42 HV of the pure aluminum to 143 HV at a rotation speed and a tool pin length of 1500 rpm and 3.2, respectively.

In this article, the analytical and numerical solution of a one-dimensional space-time fractional advection diffusion equation is presented. The separation of variables method is used to carry out the analytical solution, the basis of the system eigenfunction and their corresponding eigenvalue for basic equation is determined, and the numerical solution is based on constructing the Crank-Nicolson finite difference scheme of the equivalent partial integro-differential equations. The convergence and unconditional stability of the solution are investigated. Finally, the numerical and analytical experiments are given to verify the theoretical analysis.

The selection of high-entropy alloys (HEAs), which are relatively lightweight and have unique mechanical properties, remains a substantial challenge. In this study, six new HEAs were designed from the relatively low-cost Fe–Mn–Ni–Cr–Al–Si system using Thermo-Calc software, and then manufactured using a casting process. The effects of the atomic ratio of the alloying elements on the microstructures and mechanical properties of these alloys in the as-cast condition were systematically investigated. Brittle body-centered cubic BCC/B2 and silicide phases were found in relatively large amounts in the form of dendritic structure within large equiaxed grains with fine needle-shaped phases in the Fe30Mn15Ni20Cr15Al10Si10 and Fe35Mn15Ni20Cr15Al10Si5 alloys, in addition to the face-centered cubic (FCC) phase. When the contents of Mn and Ni were increased in the Fe35Mn25Ni15Cr15Al5Si5 and Fe35Mn20Ni20Cr15Al5Si5 alloys, the amounts of brittle phases were reduced; however, the ductile FCC phase is not significant. The FCC phase amount, which appeared as a honeycombed structure, was more than enough when the Si content was decreased to 3%. Broad relationships between the chemical composition of the alloys, especially the Si content, and the hardness and compression properties’ measurements were established. As the Si content decreased, both the hardness and compression properties of the resulting alloy also decreased. The experimental observation of the six HEAs matched the equilibrium phases predicted by the Thermo-Calc calculations.

In this study, a multi-component FeMnNiCrAlSi high-entropy alloy, chosen through Thermo-Calc® software (2021a, Stockholm, Sweden) calculation and produced by electric arc melting, was studied for phase continents and mechanical properties. The results elucidated that the cold rolled condition (area reduction ratio about 86%) was in the form of elongated grains with a dendritic structure. Also, small amounts of the BCC phase were precipitated at the grain boundaries. The annealed sample shows features of BCC phase and different sizes of intermetallics. These results coincided with the predictions of Thermo-Calc® software calculations. A cold rolled sample showed high compressive yield strength of about 950 MPa, and the annealed sample had only half the strength of the cold rolled condition. The cold rolled sample shows the highest micro-hardness. The wear resistance of the annealed condition was significantly improved at room temperature and at 200 °C. The brittle phases in the annealed condition have a positive impact on the wear resistance.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), also known as COVID-19, is currently developing into a rapidly disseminating and an overwhelming worldwide pandemic. In severe COVID-19 cases, hypercoagulability and inflammation are two crucial complications responsible for poor prognosis and mortality. In addition, coagulation system activation and inflammation overlap and produce life-threatening complications, including coagulopathy and cytokine storm, which are associated with overproduction of cytokines and activation of the immune system; they might be a lead cause of organ damage. However, patients with severe COVID-19 who received anticoagulant therapy had lower mortality, especially with elevated D-dimer or fibrin degradation products (FDP). In this regard, the discovery of natural products with anticoagulant potential may help mitigate the numerous side effects of the available synthetic drugs. This review sheds light on blood coagulation and its impact on the complication associated with COVID-19. Furthermore, the sources of natural anticoagulants, the role of nanoparticle formulation in this outbreak, and the prevalence of thrombosis with thrombocytopenia syndrome (TTS) after COVID-19 vaccines are also reviewed. These combined data provide many research ideas related to the possibility of using these anticoagulant agents as a treatment to relieve acute symptoms of COVID-19 infection.

A FABA BEAN (Vicia faba L.) is one of the most significant field crops due to its great nutritional value for humans and animals. However, they were attacked from the roots by parasitic weed plants like broomrape (Orobanche crenata F.), which destroys their host due to their rapid development and deficiency in chlorophyll, a necessary component for photosynthesis. This study was carried out during winter seasons 2020/2021 and 2022/2023 at naturally infested field in Qaha Research Station, Plant Protection Research Institute, Qalyubia Governorate, Egypt. The goal of this study was to apply an alternative strategy of crop protection against broomrape weed control by two chemical treatments including indole acetic acid and salicylic acid to enhance systemic defense responses of faba bean plants. Allelochemical treatments by using trap crops as flax and radish with the main plant that stimulate suicidal broomrape germination in their fields. The obtained results of chemical control illustrated that biochemical assay conducted an increase in total chlorophyll, total phenols and peroxidase activity during the two seasons for IAA and SA respectively. Compared with the allelochemical control they conducted, an increase in total chlorophyll, total phenols for flax and radish were observed. Increasing total protein, prolin and peroxidase enzyme for flax during the two seasons were also observed. Furthermore, all treatments could be used as an integrated control strategies to increase faba bean growth vegetation, decrease the number of spikes per m2 and spikes dry weight per m2 by increasing of broomrape weed control during both seasons. [ABSTRACT FROM AUTHOR]

This work aims to optimize the main YAG fiber laser parameters to weld 304L stainless steel plates of 3 mm thick. Different laser powers (2500, 2000, and 1500 W) and speeds (60, 40, and 20 mm/s) were used and merged in heat input, maintaining the defocusing distance at –2 mm to get full penetration. The weld quality and the effect of the laser heat input on the microstructures of the weld and heat-affected zones were investigated. Besides, the fracture strength of the welded joints and hardness distribution through the cross-sections were evaluated. The weld width has a direct relationship with heat input. The laser power of 2800 W produced full penetration joints without any macro defects while reduction in laser power pronounced partial penetration defects. The size of the heat-affected zone in all the processing parameters was very small. The microstructure of the weld zone shows columnar dendrite austenite grains with small arm spacing in most of the welded zone. The size of the dendrites became finer at lower heat input. At a higher heat input, a reasonable amount of lathy equiaxed grains with some delta ferrite occurred. A small amount of delta ferrite was detected in the heat-affected zone, which prevented the crack formation. The hardness of the weld metal was much higher than that of the base metal in all processing parameters and it has a reverse relationship with the heat input. The fracture strength of the welded joints was very close to that of the base metal in the defect-free samples and it increased with decreasing the heat input.

This paper presents a practical numerical method, an implicit finite-difference scheme for solving a two-dimensional time-space fractional Fokker–Planck equation with space–time depending on variable coefficients and source term, which represents a model of a Brownian particle in a periodic potential. The Caputo derivative and the Riemann–Liouville derivative are considered in the temporal and spatial directions, respectively. The Riemann–Liouville derivative is approximated by the standard Grünwald approximation and the shifted Grünwald approximation. The stability and convergence of the numerical scheme are discussed. Finally, we provide a numerical example to test the theoretical analysis.

This paper seeks to improve the photovoltaic (PV) system efficiency using metaheuristic, optimized fractional order incremental conductance (FO-INC) control. The proposed FO-INC controls the output voltage of the PV arrays to obtain maximum power point tracking (MPPT). Due to its simplicity and efficiency, the incremental conductance MPPT (INC-MPPT) is one of the most popular algorithms used in the PV scheme. However, owing to the nonlinearity and fractional order (FO) nature of both PV and DC-DC converters, the conventional INC algorithm provides a trade-off between monitoring velocity and tracking precision. Fractional calculus is used to provide an enhanced dynamical model of the PV system to describe nonlinear characteristics. Moreover, three metaheuristic optimization techniques are applied; Particle Swarm Optimization (PSO), Ant Colony Optimization (ACO), and AntLion Optimizer (ALO) are used for tuning the FO parameters of the proposed INC-MPPT. A MATLAB-Simulink-based model of the PV and optimization have been developed and simulated for different INC-MPPT techniques. Different techniques aim to control the boost DC-DC converter towards the MPP. The proposed optimization algorithms are, also, developed and implemented in MATLAB to tune the target parameters. Four performance indices are also introduced in this research to show the reliability of the comparative analysis of the proposed FO-INC with metaheuristic optimization and the conventional INC-MPPT algorithms when applied to a dynamical PV system under rapidly changing weather conditions. The simulation results show the effective performance of the proposed metaheuristic optimized FO-INC as a MPPT control for different climatic conditions with disturbance rejection and robustness analysis.