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An exceptional method of incorporating Sn ions into Zinc Oxide (ZnO) using a tandem system of Pulsed Laser Deposition (PLD) and Radio-Frequency Magnetron Sputtering (RFMS) to synthesize and functionalize ZnO nanostructures is demonstrated in this study for gas-sensing application. The RFMS power was varied up to 50 W to sputter a pure Sn metal target, while simultaneously or successively growing ZnO nanostructures on a templated MgO substrate and on an Au-plated Al2O3 gas sensor, via PLD process at the substrate temperature of 700 °C in 100–500 millitorr oxygen/argon gas background. The morphologies of the grown Sn-ZnO nanostructures were characterized by Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), and X-ray Diffraction (XRD), and while their chemical/oxidation states and optical properties were analyzed by X-ray photospectroscopy (XPS) and photoluminescence (PL), respectively. For simultaneous deposition, the resulting (0002)-dominated 2D grain-like ZnO nanostructures were influenced by the interaction of the dynamic PLD plasma with static RFMS plasma at different powers. For successive growth, at 50 W-RF power, a remarkable increase in the sensor response to 50-ppm carbon monoxide (CO) gas was observed at 250 °C, which could be attributed to the creation of more adsorption sites in the Sn-ZnO depletion region caused by the replacement of some Zn sites with Sn ions in the ZnO matrix. This study, therefore, exhibits the viability of this hybrid system to design, synthesize, and functionalize Sn-ZnO nanomaterials, either by simultaneous/successive deposition, for gas-sensing applications.

Viral infections trigger inflammation by controlling ATP release. CD39 ectoenzymes hydrolyze ATP/ADP to AMP, which is converted by CD73 into anti-inflammatory adenosine (ADO). ADO is an anti-inflammatory and immunosuppressant molecule which can enhance viral persistence and severity. The CD39-CD73-adenosine axis contributes to the immunosuppressive T-reg microenvironment and may affect COVID-19 disease progression. Here, we investigated the link between CD39 expression, mostly on T-regs, and levels of CD73, adenosine, and adenosine receptors with COVID-19 severity and progression. Our study included 73 hospitalized COVID-19 patients, of which 33 were moderately affected and 40 suffered from severe infection. A flow cytometric analysis was used to analyze the frequency of T-regulatory cells (T-regs), CD39+ T-regs, and CD39+CD4+ T-cells. Plasma concentrations of adenosine, IL-10, and TGF-β were quantified via an ELISA. An RT-qPCR was used to analyze the gene expression of CD73 and adenosine receptors (A1, A2A, A2B, and A3). T-reg cells were higher in COVID-19 patients compared to healthy controls (7.4 ± 0.79 vs. 2.4 ± 0.28; p < 0.0001). Patients also had a higher frequency of the CD39+ T-reg subset. In addition, patients who suffered from a severe form of the disease had higher CD39+ T-regs compared with moderately infected patients. CD39+CD4+ T cells were increased in patients compared to the control group. An analysis of serum adenosine levels showed a marked decrease in their levels in patients, particularly those suffering from severe illness. However, this was paralleled with a marked decline in the expression levels of CD73. IL-10 and TGF-β levels were higher in COVID-19; in addition, their values were also higher in the severe group. In conclusion, there are distinct immunological alterations in CD39+ lymphocyte subsets and a dysregulation in the adenosine signaling pathway in COVID-19 patients which may contribute to immune dysfunction and disease progression. Understanding these immunological alterations in the different immune cell subsets and adenosine signaling provides valuable insights into the pathogenesis of the disease and may contribute to the development of novel therapeutic approaches targeting specific immune mechanisms.

Herein, Fe3O4 core-TiO2/mesoSiO2 and Fe3O4 core-mesoSiO2/TiO2 double shell nanoparticles were prepared by first (R1) and second (R2) routes and applied for the removal of methylene blue. The reported adsorption capacities for R1-0.2, R1-0.4 and R2 samples were 128, 118 and 133 mg.g−1, respectively, which were obtained after 80 min as equilibrium contact time, and pH of 6 using a methylene blue concentration of 200 ppm. The adsorption of methylene blue using the prepared Fe3O4 core-meso SiO2/TiO2 double shell was analyzed by kinetic and isotherms models. In addition, thermodynamic investigations were applied to assess the spontaneous nature of the process. The obtained results confirmed that the pseudo-second order model is well fitted with the adsorption data and the Freundlich-isotherm assumption suggested a multilayer adsorption mechanism. In addition, results of the thermodynamic investigation indicated that ΔG° was in the range of −2.3 to −6.8 kJ/mol for R1-0.2, −2.8 to −6.3 kJ/mol for R1-0.4 and −2.0 to −5.2 kJ/mol for R2. In addition, the ΔH° and ΔS° values were found in the range of 26.4 to 36.19 kJ.mol−1 and 94.9 to 126.3 Jmol−1 K−1, respectively. These results confirm that the surfaces of Fe3O4 core-mesoSiO2/TiO2 and Fe3O4 core-TiO2/mesoSiO2 double shell exhibit a spontaneous tendency to adsorb methylene blue from the aqueous solutions. The achieved performance of Fe3O4 core-meso SiO2/TiO2 and Fe3O4 core-TiO2/meso SiO2 double shell as adsorbent for methylene blue removal will encourage future research investigations on the removal of a broad range of contaminants from wastewater.

Cobalt oxide, a multifunctional, anti-ferromagnetic p-type semiconductor with an optical bandgap of ~2.00 eV, exhibits remarkable catalytic, chemical, optical, magnetic, and electrical properties. In our study, cobalt oxide nanoparticles (Co3O4 NPs) were prepared by the green synthesis method using dried fruit extracts of Hyphaene thebaica (doum palm) as a cost-effective reducing and stabilizing agent. Scanning electron microscopy (SEM) depicts stable hollow spherical entities which, consist of interconnected Co3O4 NPs, while energy-dispersive X-ray spectroscopy (EDS) indicates the presence of Co and O. The obtained product was identified by X-ray diffraction (XRD) that showed a sharp peak at (220), (311), (222), (400), (511) indicating the high crystallinity of the product. The Raman peaks indicate the Co3O4 spinel structure with an average shift of Δν~9 cm−1 (191~470~510~608~675 cm−1). In the Fourier transform infrared spectroscopy (FT-IR) spectrum, the major bands at 3128 cm−1, 1624 cm−1, 1399 cm−1, 667 cm−1, and 577 cm−1 can be attributed to the carbonyl functional groups, amides, and Co3O4 NPs, respectively. The photocatalytic activity of the synthesized NPs was evaluated by degrading methylene blue dye under visible light. Approximately 93% degradation was accomplished in the reaction time of 175 min at a catalyst loading of 1 g/L under neutral pH. This study has shown that Co3O4 is a promising material for photocatalytic degradation.

Heavy metal toxicity in water is a serious problem that may have harmful effects on human health and the ecosystem. Lead [Pb(II)] and cadmium [Cd(II)] are two such heavy metal ions, present in water, whose severity is well-known and well-studied. In the current research, magnetic biochar composite (MBC) is studied as an adsorbent material for the effective removal of lead and cadmium ions from water solutions. Magnetite (Fe3O4) nanoparticles and pine-needle-derived ultrasonicated magnetic biochar were used in different weight ratios to prepare APTES (3-aminopropyl triethoxysilane)-functionalized MBC (FMBC). An average crystalline size of ~10 nm for magnetite NPs was obtained via XRD analysis. The adsorption characteristics of both Pb(II) and Cd(II) ions were investigated in a batch experiment. The FTIR spectra of raw biochar, MBC, FMBC, and metal-loaded FMBC were obtained at different stages. The decrease in the intensity of the –NH2 functional group in the FTIR spectra of the residue confirmed the successful adsorption of heavy metal ions. The SEM-EDX spectra of the residue showed the uniform adsorption of Pb(II) and Cd(II) heavy metal ions onto the surface of the adsorbent. Magnetic biochar composite (MBC) was found to be a very effective adsorbent at basic pH, as a maximum of 97% instantaneous heavy metal removal was observed for both ions in synthetic water solutions. The Langmuir isotherm model predicted the monolayer adsorption and good affinity between the metal ions and adsorbent. The prepared MBC is low-cost, environmentally friendly, and it has shown good adsorption performance. Therefore, our study suggests that the magnetic biochar composite under study is an effective adsorbent for lead and cadmium metal ion removal from aqueous solutions at normal room temperature. Only a few hundred milligrams of the adsorbent dose is sufficient to remove higher concentrations (~100 ppm) of lead and cadmium at basic pH conditions of aqueous solutions.

Titanium dioxide nanoparticles (TiO2 NPs) have been widely used in food, cosmetics, and biomedical research. However, human safety following exposure to TiO2 NPs remains to be fully understood. The aim of this study was to evaluate the in vitro safety and toxicity of TiO2 NPs synthesized via the Stöber method under different washing and temperature conditions. TiO2 NPs were characterized by their size, shape, surface charge, surface area, crystalline pattern, and band gap. Biological studies were conducted on phagocytic (RAW 264.7) and non-phagocytic (HEK-239) cells. Results showed that washing amorphous as-prepared TiO2 NPs (T1) with ethanol while applying heat at 550 °C (T2) resulted in a reduction in the surface area and charge compared to washing with water (T3) or a higher temperature (800 °C) (T4) and influenced the formation of crystalline structures with the anatase phase in T2 and T3 and rutile/anatase mixture in T4. Biological and toxicological responses varied among TiO2 NPs. T1 was associated with significant cellular internalization and toxicity in both cell types compared to other TiO2 NPs. Furthermore, the formation of the crystalline structure induced toxicity independent of other physicochemical properties. Compared with anatase, the rutile phase (T4) reduced cellular internalization and toxicity. However, comparable levels of reactive oxygen species were generated following exposure to the different types of TiO2, indicating that toxicity is partially driven via non-oxidative pathways. TiO2 NPs were able to trigger an inflammatory response, with varying trends among the two tested cell types. Together, the findings emphasize the importance of standardizing engineered nanomaterial synthesis conditions and evaluating the associated biological and toxicological consequences arising from changes in synthesis conditions.

In this paper, a unique hybrid approach to design and synthesize 2D/3D Al2O3-ZnO nanostructures by simultaneous deposition is presented. Pulsed laser deposition (PLD) and RF magnetron sputtering (RFMS) methods are redeveloped into a single tandem system to create a mixed-species plasma to grow ZnO nanostructures for gas sensing applications. In this set-up, the parameters of PLD have been optimized and explored with RFMS parameters to design 2D/3D Al2O3-ZnO nanostructures, including nanoneedles/nanospikes, nanowalls, and nanorods, among others. The RF power of magnetron system with Al2O3 target is explored from 10 to 50 W, while the ZnO-loaded PLD’s laser fluence and background gases are optimized to simultaneously grow ZnO and Al2O3-ZnO nanostructures. The nanostructures are either grown via 2-step template approach, or by direct growth on Si (111) and MgO substrates. In this approach, a thin ZnO template/film was initially grown on the substrate by PLD at ~300 °C under ~10 milliTorr (1.3 Pa) O2 background pressure, followed by growth of either ZnO or Al2O3-ZnO, using PLD and RFMS simultaneously under 0.1–0.5 Torr (13–67 Pa), and Ar or Ar/O2 background in the substrate temperate range of 550–700 °C. Growth mechanisms are then proposed to explain the formation of Al2O3-ZnO nanostructures. The optimized parameters from PLD-RFMS are then used to grow nanostructures on Au-patterned Al2O3-based gas sensor to test its response to CO gas from 200 to 400 °C, and a good response is observed at ~350 °C. The grown ZnO and Al2O3-ZnO nanostructures are quite exceptional and remarkable and have potential applications in optoelectronics, such in bio/gas sensors.

Thermal treatment is applied for the direct conversion of palm stalk waste to Fe3O4 (np)@carbon sheets (Fe3O4 (np)@CSs). The effect of conversion temperature was investigated. The TEM examination of the prepared magnetic Fe3O4 (np)@CSs showed the formation of Fe3O4 (np) in a matrix of carbon sheets as a coated layer with surface functional groups including carbonyl and hydroxyl groups. Removal of dyes such as methyl orange, methylene blue, and neutral red was achieved using fabricated Fe3O4 (np)@CSs which were prepared at 250 °C, 400 °C, and 700 °C in a weak acidic medium. By studying the contact time effect for the adsorption of methylene blue, neutral red, and methyl orange, using the fabricated Fe3O4 (np)@CSs which were prepared at 250 °C and 400 °C, equilibrium occurred between 120 min and 180 min. In addition, the first-order and second-order kinetic models were applied to the adsorption data. The results revealed that the adsorption data fit better with the second-order kinetic model. Furthermore, the Freundlich model was found to be more suitable for describing the process of the separation of the dyes onto Fe3O4 (np)@CSs which were prepared at 250 °C and 400 °C, suggesting heterogenous surfaces and multi-layer adsorption.

A number of important fused heterocyclic systems have been prepared by the reaction of 4-((3,5-diamino-1H-pyrazol-4-yl)-diazenyl)-N-(thiazol-2-yl)-benzenesulfonamide with some bifunctional nucleophiles such as ethyl acetoacetate, acetylacetone or arylidenemalonononitrile derivatives to obtain pyrazolo[1,5-a]pyrimidine derivatives. The structures of the newly synthesized compounds were determined based on their IR, 1H and 13C NMR and mass spectroscopic data. Most of the compounds produced showed good antibacterial and antifungal activity.

Novel Chitosan-g-Octanal Schiff base amphiphilic polymer has been developed by click grafting technique and evaluated successfully in removing different types of oils spills. The chemical structure and the morphological changes of the developed Chitosan-g-Octanal Schiff base amphiphilic polymer have been followed using FT-IR spectroscopy and SEM. The amphiphilic character of the developed Chitosan-g-Octanal Schiff base polymer has been controlled through variations of the Octanal grafting percentages from 38% to 82%. Dramatic changes of the Chitosan-g-Octanal Schiff base polymer solubility have been founded. The ion exchange capacity and water uptake have been affected in the same manner. The oils adsorption capacity was founded in direct relation to the Octanal grafting percentages and followed the order: mineral

The objective of this study is to develop efficient pH-sensitive hydrogel based on aminated chitosan (AmCs) and gelatin (Gel) biopolymers for oral drug delivery. Herein, AmCs was chemically crosslinked with gelatin (Gel) biopolymer with different ratios, while their structures, thermal profiles and morphological properties were investigated by FTIR, TGA and SEM characterization tools, respectively. Moreover, gel-content, crosslinking density and rheological analysis were also performed. The results clarified that the developed AmCs-Gel crosslinked hydrogel displayed variable pH-sensitive swelling profiles. By increasing AmCs ratio, the swelling ratio was boosted at pH 1.2 and declined at pH 7.4. Besides, by increasing gelatin ratio in the hydrogel matrix, the loading efficiency of Oseltamivir phosphate (as a model of drug) was augmented and reached maximum value of 79.0% by AmCs-Gel (2:3) crosslinked hydrogel. The in vitro drug release profiles were investigated for 6 h in simulated gastric fluid [SGF; pH 1.2] and simulated colon fluid [SCF; pH 7.4]. Variable release profiles were realized depending on variation of AmCs and Gel ratios in the crosslinked hydrogel matrix. Finally, the formulated smart crosslinked AmCs-Gel hydrogels demonstrated acceptable biodegradability with no cellular toxicity, suggesting their applicability as pH-sensitive oral drug carriers.

The development of cheap and efficient proton conducting polymers attracts scientists' attention, resulting in its potential role in fuel cell applications. This work synthesized a novel cellulose acetate-g-poly(sodium 4-styrene sulfonate) via free radical polymerization using potassium persulfate (KPS) as an initiator. The effects of varying KPS concentration, cellulose acetate (CA), sodium 4-styrene sulfonate (Na-SSA) content, reaction time, and temperature on the grafting parameters were studied. Grafting parameters, including the grafting yield (GY %), Add-on (%) and grafting efficiency (GE %) of the grafting reaction, were evaluated. Additionally, FTIR, TGA, DSC, 1HNMR and EDX analyses were studied. The developed graft copolymers membranes illustrated increased water uptake values and ion exchange capacity (IEC) with the add-on (%). Furthermore, the proton conductivity of the developed graft copolymers was found superior (4.77 × 10−3 S.cm−1) to the pristine CA membrane (0.035 × 10−3 S.cm−1).

A novel cellulose acetate-g-poly (2-acrylamido-2-methylpropane sulfonic acid-co- methyl methacrylate) copolymer was prepared via free radical polymerization for the first time. The chemical structure of the graft copolymer was confirmed using FT-IR, 1H NMR and EDX. The TGA and DSC investigated the thermal changes. Factors affecting the grafting process were studied and various grafting characteristic parameters such as grafting efficiency (%), grafting yield (%) and add-on value (%) were determined. Flexible membranes based on different graft copolymer compositions were fabricated by simple solution casting. Physicochemical properties including ion exchange capability (IEC), water uptake (WU) and proton conductivity (σ) were evaluated. These membranes demonstrated higher IEC, WU and conductivity than the pristine CA. The maximum proton conductivity of the CA-g-poly (2-acrylamido-2-methylpropane sulfonic acid-co- methyl methacrylate) copolymer membrane (68%; Add-on %) was found to be 6.44 × 10−3 S/cm compared with 0.035 × 10−3 S/cm of the pristine CA. Thus, the appropriate graft copolymer composition will allow fine-tuning of the physical characteristics and led to several potential applications, such as polyelectrolyte fuel cells membranes or biodiesel production.

Failure Modes, Effects, and Criticality Analysis are widely used to assess the failure modes of a system, along with their causes and effects. Several Multi-Criteria Decision-Making approaches have been developed to overcome the limitations of the traditional FMECA. In these approaches, several multiple criteria are considered to determine the criticality values and assign criticality ranks. In these developed approaches, only one expert can involve in criticality analysis. By incorporating several experts from design, manufacturing, and maintenance domains in the criticality analysis accuracy of the results can be improved. This paper proposes a new integrated Expert Judgment-based Preference Section Index (ExJ-PSI) model that combines MCDM approaches and integrates expert opinions. The proposed model is applied to a boiler system used in the textile industry. The results are compared with those obtained from the conventional FMECA and normalized median method. In the present study, the opinions of seven experts from various domains and organizations are discussed. To normalize the collected data, one scale is developed by considering four expert criteria, such as the experience of the expert, the number of boilers he is handling, the number of employees under his supervision, and the proficiency in the field. The proposed model is more effective and flexible in handling and analyzing data of complex configured systems consisting of many subsystems, components, and failure modes. The analysis reveals that the feed water pump, feed water pump motor, supply water temperature sensor, return water temperature sensor, header, and coal feed motor are some of the most critical components of the boiler system.

Every day, mining corporations grow and develop over Egypt’s Eastern Desert in search of gold, silver, and other metals. Mineral resources in Egypt are a powerful tool for increasing national income. In this study, we are interested in mineral exploration, such as gold and porphyry deposits, using aeromagnetic data, applying various processing techniques such as First Vertical Derivative, Total Horizontal Gradient, Analytical Signal, Tilt Derivative, and the center of exploration targeting (CET). The study area is located at the Central Eastern Desert, which includes the Barramiya, Abu Marwa, and Abu Mireiwah regions. The analysis of the delineated structural trends shows that the N–S, NW–SE, and NE–SW are the most effective directions for managing deposits in the investigated area. A minor trend is also shown in the E–W direction and corresponds to the alteration zones reported by geology and prior investigations. Mineralization zones occur most frequently at the contact between ophiolitic serpentinite, sediments, and other rock types. This study intends to add more about the use of the recently developed technology of CET grid analysis for mineral exploration and structural interpretation across the Central Eastern Desert. The CET porphyry analysis map shows locations where several occurrences of porphyry deposits are probable. The newly discovered spots are similar to the area’s usual deposit sites. This study proves that aeromagnetic data are significant in mineral exploration since they are useful for the discovery of the structure and shear zones controlling the mineralization zones.

Thirty groundwater samples were taken from Assiut’s northern outskirts. The physicochemical properties of these samples were investigated. For the evaluation of water–rock interaction, the saturation index (SI), chloro-alkaline indices (CAI1 and CAI2), Gibbs ratios for cations and anions (GC and GA), principal component analysis (PCA), and hierarchical cluster analysis (HCA) were used. (1) With the exception of five samples that were supersaturated, the rest of the groundwater samples were under-saturated with carbonate mineral dissolution (calcite, dolomite, and aragonite) and evaporite mineral dissolution (anhydrite, gypsum, halite, and sylvite). (2) The presence of ion exchange between alkali elements (Na+ + K+) and earth alkaline elements (Ca2+ + Mg2+) is explained by the positive values of the chloro-alkaline indices. (3) In four groundwater samples, negative chloro-alkaline indices suggest reverse ion exchange and an increasing alkali element content. (4) The Gibbs diagram demonstrates that, with the exception of four samples that reflect saline groundwater, the majority of the groundwater samples are freshwater recharging from the fresh surface water in the research area. (5) Groundwater types include Ca-HCO3 (11%), Mg-HCO3 (48%), Na-HCO3 (23%), Mg-Cl (13%), and Na-Cl (3%). (6) The alkali, earth alkaline elements, and sulphate are the key controls on groundwater salinity, according to PCA and HCA. (7) The somewhat saline groundwater in the research area’s western desert margins should not be used since it poses a health danger to people.

According to the modern era, zinc is one of the best replacements for human bio-implants due to its acceptable degradation, nominal degradable rate, and biocompatibility. However, alloying zinc with other nutrient metals is mandatory to improve the mechanical properties. In this research, Zn-4Ti-4Cu was alloyed with calcium and phosphorous through a powder metallurgical process to make guided bone regeneration (GBR). First, the sintering temperature of the alloy was found with the usage of thermogravimetric analysis (TGA). Tensile and compression tests showed the suitability of the alloy in strength. The microstructural characteristics were provided with EDS and SEM. The different phases of the alloy were detected with X-ray diffraction (XRD). We can clearly depict the precipitates formed and the strengthening mechanism due to titanium addition. An electrochemical corrosion (ECM) test was carried out with simulated body fluid (Hank’s solution) as the electrolyte. Cytotoxicity, biocompatibility, mechanical properties, and corrosion resistance properties were studied and discussed.

Because of the significant environmental pollution produced by human activities, there is an ongoing need to develop transportable, simple, and reliable techniques for determining trace contaminants on the spot. This work reported a colorimetric detection method for aqueous Cr(VI) sensing by maleic acid-functionalized gold nanoparticles with high sensitivity and selectivity. The wine-red color of the probe solution can change to gray even in the presence of 1.0 µg L−1 of aqueous Cr(VI). Moreover, with the assistance of a smartphone installed with a commercially available color scan application software, its concentration of could be readily quantified on the spot without the help of UV-Vis spectrometer. The detection limit could reach as low as 0.1 µg L−1 with linear range from 0.2 to 2.0 µg L−1. Most importantly, the coefficient variation of the proposed smartphone-based method was equivalent to that of colorimetry, demonstrating the high accuracy of the proposed method for accurate detection of Cr(VI) in resource-constrained countries. Conclusively, with the help of the smartphone, this nanomaterials-based probe demonstrated the potential in the field of environment monitoring for on-site quantitative detection of any pollutants in resource-constrained countries.

Environmental pollution caused by lead and vanadium is almost entirely due to industrial activities, such as the production of steel, pigments, photographic materials and insecticides. The concentration and chemical speciation of Pb and V were studied in surface sediments from 11 stations off Nile River Delta. Sequential extraction technique was applied to assess the four (exchangeable, acid-reducible, oxidizable-organic and residual) fractions in surface sediment, also to obtain an overall classification of lead and vanadium pollution in this area through its spatial distribution. This investigation was the first study on the basis of the chemical speciation of Pb and V in surface sediments off Nile Delta. The total concentrations of metals were ranged (22.8–41.3 μg g−1) for Pb and (66.6–142.5 μg g−1) for V. The chemical speciation in most sampling stations was in the order of Residual > acid-reducible > oxidizable-organic > exchangeable for Pb and in the order of Residual > oxidizable-organic > exchangeable > acid-reducible for V. The results showed that the Pb in surface sediments off Nile River Delta existed in the nonresistant fractions while vanadium existed in the resistant fractions. The degree of surface sediments contamination was determined for individual contamination factors (ICF) and global contamination factor (GCF). The result of ICF and GCF values showed that those stations located in the vicinity of municipal area (especially Lake Burullus outlet) had high potential risk to fauna and flora of study area. Risk assessment code (RAC) analysis indicated that although Pb presented a moderate overall risk to the aquatic environment, vanadium showed a low risk (RAC

Chromium oxide supported on mesoporous organo-silica (MOS) was synthesized with different Cr loading by an incipient method. The catalytic performance of a Cr(x)/MOS catalyst for CO2-based ethane dehydrogenation was investigated. The synthesized catalysts were characterized by XRD, BET, TEM, SEM, XPS, FTIR, and UV–Vis DR measurements. The textural properties of the prepared samples showed that the mesoporous nature of MOS sample was not disturbed by chromium impregnation. Among the prepared samples, Cr(8)/MOS catalyst exhibited good distribution of chromium species along with superior concentration of Cr6+ and the highest recorded Cr6+/Cr3+ ratio. The results revealed that the superior catalytic performance was reached at Cr(8)/MOS, with 50.4% and 90.1% of ethane conversion and ethylene selectivity, respectively. The catalytic activity decreased slowly over reaction time; it declined approximately 22% after 10 h of stream operation. The roles of CO2-based ethane dehydrogenation were also studied, where carbon dioxide can be a source of lattice oxygen and as a hydrogen consumer in reverse water–gas shift (RWGS) reaction. The effect of various catalytic factors, such as catalytic temperature, reaction time, space gas velocity, and CO2 partial pressure on the conversion of ethane, yield, and selectivity to ethylene, were investigated as well.

Onions contain high antioxidants compounds that fight inflammation against many diseases. The purpose was to investigate some selected bioactive activities of onion varieties (Yellow, Red, Green, Leek, and Baby). Antioxidant assays and anti-inflammatory activities such as NO production with the addition of some bioactive components were determined and analyzed by using a spectrophotometer. Gas chromatography and mass spectrometry (GC–MS) was used for the volatile compounds, while an Atomic absorption spectrometer was used for mineral determinations. Red variety achieved the highest antioxidant activities. The total flavonoids were between (12.56 and 353.53 mg Quercetin/gin dry weight) (dw) and the total phenol was (8.75–25.73 mg/g dw). Leek, Yellow and Green extracts achieved highly anti-inflammatory values (3.71–4.01 μg/mL) followed by Red and Baby extracts, respectively. The highest contents of sodium, potassium, zinc, and calcium were established for Red onions. Furfuraldehyde, 5-Methyl-2-furfuraldehyde, 2-Methyl-2-pentenal, and 1-Propanethiol were the most predominant, followed by a minor abundance of the other compounds such as Dimethyl sulfide, Methyl allyl disulfide, Methyl-trans-propenyl-disulfide, and Methyl propyl disulfide. The results recommend that these varieties could act as sources of essential antioxidants and anti-inflammatories to decrease inflammation and oxidative stresses, especially red onions that recorded high activities.

Background: Radiological diagnosis of cervical spondylotic myelopathy should be made as early as possible to obtain favourable clinical outcomes when compared with later stages. Diffusion tensor imaging can reveal early structural changes of the cord in patients with cervical compressive myelopathy. Aim: This study aimed to assess the role of magnetic resonance diffusion tensor imaging in the accurate evaluation of cervical spondylotic myelopathy. Patients and methods: This prospective study included a group of 60 patients with neurological symptoms suggestive for cervical spondylotic myelopathy and a control group of 30 healthy subjects. The clinical severity of compressive myelopathy was assessed based on the European myelopathy score. Magnetic resonance diffusion tensor imaging and tractography were done for all patients and controls. Results: Fractional anisotropy values at the most compressed segments of spinal cord are lower while apparent diffusion coefficient values of the same segments are higher than healthy segments in controls. Fractional anisotropy and apparent diffusion coefficient parameters had higher sensitivity (97.0% and 88.1%, respectively) than conventional T2 WIs (13.4%) and fibre tractography (10%) for the detection of early compressive myelopathy with cutoff values ≤ 0.56 and > 1.23, respectively, in differentiating between patients and control groups. Conclusion: Diffusion tensor imaging indices are valuable tools for quantitative assessment of degenerative cervical spondylotic myelopathy in addition to routine cervical spine magnetic resonance. [ABSTRACT FROM AUTHOR]

An endophytic strain of Streptomyces antimycoticus L-1 was isolated from healthy medicinal plant leaves of Mentha longifolia L. and used for the green synthesis of silver nanoparticles (Ag-NPs), through the use of secreted enzymes and proteins. UV–vis spectroscopy, Fourier-transform infrared (FT-IR), transmission electron microscopy (TEM), X-ray diffraction (XRD), and dynamic light scattering (DLS) analyses of the Ag-NPs were carried out. The XRD, TEM, and FT-IR analysis results demonstrated the successful biosynthesis of crystalline, spherical Ag-NPs with a particle size of 13–40 nm. Further, the stability of the Ag-NPs was assessed by detecting the surface Plasmon resonance (SPR) at 415 nm for one month or by measuring the NPs surface charge (−19.2 mV) by zeta potential analysis (ζ). The green-synthesized Ag-NPs exhibited broad-spectrum antibacterial activity at different concentrations (6.25–100 ppm) against the pathogens Staphylococcus aureus, Bacillus subtilis Pseudomonas aeruginosa, Escherichia coli, and Salmonella typhimurium with a clear inhibition zone ranging from (9.5 ± 0.4) nm to (21.7 ± 1.0) mm. Furthermore, the green-synthesized Ag-NPs displayed high efficacy against the Caco-2 cancerous cell line (the half maximal inhibitory concentration (IC50) = 5.7 ± 0.2 ppm). With respect to antibacterial and in-vitro cytotoxicity analyses, the Ag-NPs concentration of 100 ppm was selected as a safe dose for loading onto cotton fabrics. The scanning electron microscopy connected with energy-dispersive X-ray spectroscopy (SEM-EDX) for the nano-finished fabrics showed the distribution of Ag-NPs as 2% of the total fabric elements. Moreover, the nano-finished fabrics exhibited more activity against pathogenic Gram-positive and Gram-negative bacteria, even after 10 washing cycles, indicating the stability of the treated fabrics.

MXenes have emerged as promising materials for various mechanical applications due to their outstanding physicochemical merits, multilayered structures, excellent strength, flexibility, and electrical conductivity. Despite the substantial progress achieved in the rational design of MXenes nanostructures, the tutorial reviews on the mechanical properties of self-standing MXenes were not yet reported to our knowledge. Thus, it is essential to provide timely updates of the mechanical properties of MXenes, due to the explosion of publications in this filed. In pursuit of this aim, this review is dedicated to highlighting the recent advances in the rational design of self-standing MXene with unique mechanical properties for various applications. This includes elastic properties, ideal strengths, bending rigidity, adhesion, and sliding resistance theoretically as well as experimentally supported with various representative paradigms. Meanwhile, the mechanical properties of self-standing MXenes were compared with hybrid MXenes and various 2D materials. Then, the utilization of MXenes as supercapacitors for energy storage is also discussed. This review can provide a roadmap for the scientists to tailor the mechanical properties of MXene-based materials for the new generations of energy and sensor devices.

This article presents the findings of a study on assessment of the increase in building’s response due to accidental torsion when subjected to seismic forces. Critical stiffness and geometrical parameters that define buildings torsional response are examined including: (1) the ratio, Ω, between uncoupled torsional frequency ωθ to uncoupled translation frequencies in the direction of ground motion ωx or ωy, (2) floor plan aspect ratio, b/r, which is a function of the floor dimension and radius of gyration. The increased response is assessed on symmetric multi-storey buildings using both static and dynamic analysis methods specified by ASCE-7 and considering parameters affecting the torsional response. It was concluded that static and dynamic analysis procedures predict different accidental torsion responses. Static analysis based on the Equivalent Lateral Force (ELF) method predicts more conservative accidental torsions responses for flexible structures with Ω < 0.7~0.80, while the responses are less conservative for stiffer buildings. The conservativism in static analysis method is attributed to the response amplification factor, Ax. Floor plans and their lateral support system having frequency ratio Ω = 1 will also have a torsional radius equal to radius of gyration, and will experience drop in torsional response relative to more torsionally flexible buildings. This article presents a procedure to overcome the shortcomings of static and dynamic analysis procedures in terms of estimating accidental torsion response of symmetric building structures.

Submicron sized mesoporous spheres of TiO2 have been a potential alternative to overcome the light scattering limitations of TiO2 nanoparticles in dye-sensitized solar cells (DSSCs). Currently available methods for the growth of mesoporous TiO2 sub-microspheres involve long and relatively high temperature multi-stage protocols. In this work, TiO2 mesoporous sub-microspheres composed of ~5 nm anatase nanocrystallites were successfully synthesized using a rapid one-pot room-temperature CTAB-based solvothermal synthesis. X-Ray Diffraction (XRD) showed that the grown structures have pure anatase phase. Transmission electron microscopy (TEM) revealed that by reducing the surfactant/precursor concentration ratio, the morphology could be tuned from monodispersed nanoparticles into sub-micron sized mesoporous beads with controllable sizes (50−200 nm) and with good monodispersity as well. The growth mechanism is explained in terms of the competition between homogeneous nucleation/growth events versus surface energy induced agglomeration in a non-micelle CTAB-based soft templating environment. Further, dye-sensitized solar cells (DSSCs) were fabricated using the synthesized samples and characterized for their current-voltage characteristics. Interestingly, the DSSC prepared with 200 nm TiO2 sub-microspheres, with reduced surface area, has shown close efficiency (5.65%) to that of DSSC based on monodispersed 20 nm nanoparticles (5.79%). The results show that light scattering caused by the agglomerated sub-micron spheres could compensate for the larger surface areas provided by monodispersed nanoparticles.

A series of large-pore mesoporous silica (LPMS)-supported CrOx catalysts were synthesized by hydrothermal and impregnation methods and tested for ethane dehydrogenation in the presence of CO2 as an oxidant. To assess the effect of hydrothermal temperature treatment on the characteristics of LPMS support, different hydrothermal temperatures (100−160 °C) were studied and optimized. The optimum support was then loaded with different amounts of chromium (0, 2, 4, 8, and 11 wt % Cr). The obtained catalysts were characterized by different techniques such as XRD, BET, TEM, SEM, XPS, FTIR, and diffuse reflectance UV-Vis spectroscopy. The characterization results indicated that the sample hydrothermally treated at 130 °C exhibited the highest pore volume, a narrow pore size distribution, and a moderate BET surface area. Chromium species with various oxidation states including Cr3+, Cr6+, and α-Cr2O3 were detected in all synthesized Cr(y)/LPMS-130 catalysts. A lower Cr content resulted in the formation of Cr6+, whereas a higher Cr content dominated the α-Cr2O3 on the surface of the catalyst. Among the synthesized catalysts, the Cr(4)/LPMS-130 catalyst showed the highest Cr6+/Cr3+ ratio, indicating a good dispersion of chromium species along with a fine particle size. The ethane conversion and ethylene selectivity were 50.5 and 91.1% for Cr(4)/LPMS-130, respectively. Carbon dioxide was believed to supply enough lattice oxygen to maintain the Cr species at a higher oxidation state and to consume the hydrogen resulting from ethane cracking by a reverse water gas shift reaction.