An efficient and complete separation of precious metals from the containing secondary materials has a vital economic impact. Palladium loaded on alumina support is usually used as a catalyst in ...fertilizers industry where the recovery of the metals from the spent catalyst is practically important. Palladium was partially dissolved from the spent catalyst in hot concentrated hydrochloric acid where a large amount of aluminum is also dissolved. The main objective of this work is to find out the optimum conditions for efficient and clean dissolution of palladium with minimum attack to the alumina carrier. Palladium can form different soluble chloro-complexes which can enhance the dissolution process if an oxidizing agent is added. A small amount of hydrogen peroxide could greatly improve the dissolution of palladium in dilute hydrochloric acid while the alumina support was left nearly unaffected. Complete dissolution of palladium was achieved by leaching with a solution contains 7% HCl and 5% H
2O
2 at 60
°C for 2
h with a liquid/solid ratio of 10/1. The leach liquor contained 0.04% palladium and 0.5% aluminum and the filtered solids was a pure aluminum rich residue. Palladium could be separated from the leach liquor by reduction with formic acid solution. Heating the solution increased the efficiency of palladium reduction and also produced larger palladium particles those can be easily separated by filtration. Palladium powder of 98% purity was produced with recovery efficiency >99%.
We designed and prepared a novel series of urea derivatives with/without sulfonyl group in their structures to investigate the impact of the sulfonyl group on the biological activity of the evaluated ...compounds. Antibacterial investigations indicated that derivatives 7, 8, 9, and 11 had the most antibacterial property of all the compounds examined, their minimum inhibitory concentrations (MICs) determined against B. mycoides, E. coli, and C. albicans, with compound 8 being the most active at a MIC value of 4.88 µg/mL. Anti-cancer activity has been tested against eight human cancer cell lines; A549, HCT116, PC3, A431, HePG2, HOS, PACA2 and BJ1. Compounds 7, 8 and 9 emerged IC50 values better than Doxorubicin as a reference drug. Compounds 7 and 8 showed IC50 = 44.4 and 22.4 μM respectively against PACA2 compared to Doxorubicin (IC50 = 52.1 μM). Compound 9 showed IC50 = 17.8, 12.4, and 17.6 μM against HCT116, HePG2, and HOS, respectively. qRT-PCR revealed the down-regulation of PALB2 in compounds 7 and 15 treated PACA2 cells. Also, the down-regulation of BRCA1 and BRCA2 was shown in compound 7 treated PC3 cells. As regard A549 cells, compound 8 decreased the expression level of EGFR and KRAS genes. While compounds 7 and 9 down-regulated TP53 and FASN in HCT116 cells. Molecular docking was done against Escherichia coli enoyl reductase and human Son of sevenless homolog 1 (SOS1) and the results showed the promising inhibition of the studied proteins.
In consideration of the chromones' therapeutic potential and anticancer activity, a new series of chromanone derivatives have been synthesized through a straightforward reaction between ...6-formyl-7-hydroxy-5-methoxy-2-methylchromone (2) and various organic active compounds. The cytotoxic activity of the newly synthesized congeners was investigated against MCF-7 (human breast cancer), HCT-116 (colon cancer), HepG2 (liver cancer), and normal skin fibroblast cells (BJ1). The obtained data indicated that compounds 14b, 17, and 19 induce cytotoxic activity in the breast MCF7, while compounds 6a, 6b, 11 and 14c showed highly potent activity in the colon cancer cell lines. Overall, the results demonstrate that the potential cytotoxic effects of the studied compounds may be based on their ability to induce DNA fragmentation in cancer cell lines, down-regulate the expression level of CDK4 as well as the anti-apoptotic gene Bcl-2 and up-regulate the expression of the pro-apoptotic genes P53 and Bax. Furthermore, compounds 14b and 14c showed a dual mechanism of action by inducing apoptosis and cell cycle arrest. The docking studies showed that the binding affinity of the most active cytotoxic compounds within the active pocket of the CDK4 enzyme is stronger due to hydrophobic and H-bonding interactions. These results were found to be consistent with the experimental results.
Steel beams’ shear strength is one of the most important factors that influence how quickly webs buckle. Despite extensive studies having been performed over the previous three decades, the existing ...procedures did not achieve the necessary reliability to predict the ultimate shear resistance of plate girders. New techniques called Learner Techniques have started to be used over the last few years; these techniques were applied to calculate the steel beam shear strength. In this study, a Regression Learner Techniques model was built using data from 100 test results from previously published research. Based on the geometric and material properties of the web and flanges available in the published tests, a model was built using Artificial Neural Networks. Based on sensitivity analysis, a Cascade Forward Backpropagation Neural Networks (CFBNN) approach was utilized to anticipate the shear strength of steel beams. The proposed models outperformed current hybrid artificial intelligence models developed using the same collected datasets and demonstrated to accurately predict the ultimate shear strength. The performance of the models was evaluated using a range of statistical assessment methods, which led to a valuable conclusion. The CFBNN model achieved the highest root mean square (R2 = 0.95). The results corresponding to each test were verified by specimen shear strength values calculated by a theoretical approach. The resultant maximum shear force obtained by the proposed modified equation was compared with the experimental results and the shear force was estimated using two different approaches proposed by the European code. Finally, two approaches were used to verify the proposed model. The first approach was the data reported from an experimental shear test program conducted by the authors, and the second was the results of the shear values acquired experimentally by other researchers. Based on the test results of the previous studies and the current work, the suggested model gives an adequate degree of accuracy for estimating the shear strength of steel beams.
This paper explores a solution to safeguard buried pipes located near constructions in the Al-Bisri region of Assiut Governorate by utilizing the concept of the characteristic damage state. This ...issue has escalated due to the increasing rate of construction activity near pipelines, resulting in a multitude of legal disputes. This study investigates the behavior of buried pipes when influenced by newly constructed buildings using the finite element method. The paper employs two-dimensional models of a 12-story reinforced concrete building with a raft foundation and a series of piles supporting the buried pipe. In this study, we used the PLAXIS software, a 2D plane strain program, to conduct numerical investigations. The soil was idealized using the Mohr–Coulomb model with a 15-node triangular element, while the piles and structures were idealized with a five-node isoperimetric beam element. The point of contact between the beam and the soil was represented by the interface element. Our research examined the distance between the pipe and the footing edge and the distance between the piles and the footing edge. The finite element model results provided nodal displacements and element straining actions for analysis. The results shed light on the behavior of the sheet pile wall and sewage pipe in various situations. The largest bending moment in the sewage pipe was seen in the absence of piling, in contrast, to pile support at Rx = 0.75. The bending moment in the pipe expanded and always occurred at the same location as Rx rose. The clay layer next to the pipe’s lateral deformation was significantly reduced after piling, with the greatest deformation occurring at Rx = 0.
A new series of nitric oxide-releasing estra-1,3,5,16-tetraene analogs (NO-∆-16-CIEAs) was designed and synthesized as dual inhibitors for EGFR and MRP2 based on our previous findings on ...estra-1,3,5-triene analog NO-CIEA
against both HepG2 and HepG2-R cell lines. Among the target compounds,
(
-isomer) and
(
-isomer) displayed potent
-proliferative activity against both HepG2 and HepG2-R cell lines in comparison to the reference drug erlotinib. Remarkably, compound
resulted in a prominent reduction in EGFR phosphorylation at a concentration of 1.20 µM with slight activity on the phosphorylation of MEK1/2 and ERK1/2. It also inhibits MRP2 expression in a dose-dependent manner with 24% inhibition and arrested the cells in the S phase of the cell cycle. Interestingly, compound
(estratetraene core) exhibited a twofold increase in
-proliferative activity against both HepG2 and HepG2-R in comparison with the lead estratriene analog, demonstrating the significance of the designed ∆-16 unsaturation. The results shed a light on compound
and support further investigations to combat multidrug resistance in chemotherapy of hepatocellular carcinoma patients.
The most crucial event in a mining project is the selection of an appropriate mining method (MMS). Consequently, determining the optimal choice is critical because it impacts most of the other key ...decisions. This study provides a concise overview of the development of multiple selection methods using a cascade-forward backpropagation neural network (CFBPNN). Numerous methods of multicriteria decision-making (MCDM) are discussed and compared herein. The comparison includes several factors, such as applicability, subjectivity, qualitative and quantitative data, sensitivity, and validity. The application of artificial intelligence is presented and discussed using CFBPNN. The Chengchao iron mine was selected for this investigation to pick the optimum mining method. The results revealed that cut and fill stoping is the most appropriate mining method, followed by sublevel and shrinkage stoping methods. The least appropriate method is open-pit mining, followed by room and pillar and longwall mining methods.
(1) Background: Drug repositioning is an unconventional drug discovery approach to explore new therapeutic benefits of existing drugs. Currently, it emerges as a rapid avenue to alleviate the ...COVID-19 pandemic disease. (2) Methods: Herein, we tested the antiviral activity of anti-microbial and anti-inflammatory Food and Drug Administration (FDA)-approved drugs, commonly prescribed to relieve respiratory symptoms, against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the viral causative agent of the COVID-19 pandemic. (3) Results: Of these FDA-approved antimicrobial drugs, Azithromycin, Niclosamide, and Nitazoxanide showed a promising ability to hinder the replication of a SARS-CoV-2 isolate, with IC
of 0.32, 0.16, and 1.29 µM, respectively. We provided evidence that several antihistamine and anti-inflammatory drugs could partially reduce SARS-CoV-2 replication in vitro. Furthermore, this study showed that Azithromycin can selectively impair SARS-CoV-2 replication, but not the Middle East Respiratory Syndrome Coronavirus (MERS-CoV). A virtual screening study illustrated that Azithromycin, Niclosamide, and Nitazoxanide bind to the main protease of SARS-CoV-2 (Protein data bank (PDB) ID: 6lu7) in binding mode similar to the reported co-crystalized ligand. Also, Niclosamide displayed hydrogen bond (HB) interaction with the key peptide moiety GLN: 493A of the spike glycoprotein active site. (4) Conclusions: The results suggest that Piroxicam should be prescribed in combination with Azithromycin for COVID-19 patients.
This research investigates the influence of rock joint dip angle and spacing on the performance of arched roof tunnels. A sensitivity analysis was conducted using Rocscience RS2 software, enabling ...the evaluation of stress distribution and rock mass deformation. The analysis involved the identification of specific reference points on the tunnel’s back, walls, and floor to assess stress state, deformation, and the extent of plastic damage zones near the tunnel’s perimeter, in relation to the minimum embedment length of the primary rock support. The results revealed distinct stress patterns within the tunnel system. Tensile-induced stresses were minimal along the tunnel walls, while high compressive-induced stresses were observed around the tunnel’s back/roof and floor. Additionally, substantial rock deformation was observed at the tunnel’s periphery, as evidenced by measurements taken at the reference points. Notably, an increase in the dip angle of the joints resulted in reduced displacement, suggesting a potential strategy for mitigating deformation. Furthermore, the research highlighted the crucial role of joint spacing in ensuring tunnel stability. Decreasing joint spacing was found to impact tunnel stability significantly adversely, underscoring the importance of carefully considering joint spacing during the design and construction phases of arched roof tunnels. The analysis was validated by comparing the numerical modeling results with readings obtained from Multi-Points Borehole Extensometers (MPBXs) installed in the tunnel walls and roof. The comparison revealed variations of 16% at the tunnel’s right wall, 11% at the tunnel’s left wall, and 12% at the tunnel roof.
Slope instability of open-pit mines has adverse impacts on the overall mine profitability, safety and environment. The slope of an open-pit mine is crucially influenced by the slope geometry, quality ...of rock mass and presence of geological features and their properties. The objective of this study is to demonstrate a method to select the optimal overall slope angle of open-pit mines according to three design parameters, namely, safety (e.g., probability of instability), productivity (e.g., profit) and mining costs (e.g., cost of removal of overburden). Therefore, this study attempts a hybrid approach in which numerical modelling is integrated with probabilistic analysis to evaluate the stability of an open-pit mine at various overall slope angles. Two-dimensional elasto-plastic finite-element, RS2D, has been used to develop a series of models at different ultimate slope angles employing shear strength reduction technique (SSRT). Li’s point-estimate method of n3 has been invoked in deterministic analysis to tackle the inherent uncertainty associated with host rock mass properties. The results reveal that the mine profitability increases and the cost of overburden removal decreases as overall slope angle becomes steeper. However, the slope stability deteriorates. Therefore, it is highly advisable to combine these three design parameters (e.g., safety, productivity, and cost) together when selecting overall slope angle of open-pit mines.
PDF
