Estimation of titanium and iron in uranium by EDXRF using microdroplets on filter paper

Uranium, Fe and Ti solutions have been analyzed by EDXRF spectrometry after dispensing microdroplets of the simulated solution on filter paper fixed on a scotch tape. Precision of intensity measurements has been studied and the change in intensity with concentration behaviour is observed and discussed.     

Depolymerization Study of Pakistani Coal Solvent Evaluation Study

Depolymerization of an indigenous coal was studied in a variety of solvents at a temperature of 400 ± 10 °C in a hydrogen environment using a micro autoclave reactor for a time duration of 30 minutes. Some aliphatic, aromatic solvents as well as viscous petroleum based oils and pitches were used for evaluating them as liquefaction solvents. Amongst aliphatic solvents, 2‐propanol, and amongst aromatics, p‐creosol, gave highest yields. Petroleum pitches also proved effective, particularly their blends which caused significant depolymerization of the coal under study leading to formation of liquid products.     

Hydrothermal synthesis of leucite nanoparticles using anionic surfactant: Structural evaluation and catalytic properties

Surfactant-assisted synthesis of leucite (KAlSi₂O₆) nanoparticles was carried out by a hydrothermal method using an anionic surfactant at variable temperatures and surfactant concentrations. The newly synthesized leucite nanoparticles were characterized by FTIR, TGA, XRD, FESEM, and TEM. These nanoparticles have a wide and direct band gap at their smallest particle size (E_g = 3.30 eV), showing a significant quantum confinement effect. Samples of leucite were prepared at 180°C with different SDS concentrations 0.006, 0.007, 0.008, 0.009, and 0.01 M and were used to degrade methylene blue under ultraviolet radiations. These samples degraded methylene blue to 18.5, 31.7, 45.81, 31.61, 30.1%, respectively. The most effective catalyst is the one which was synthesized at 200°C and the CMC value of the surfactant (sodium dodecyl sulfate) having the percentage degradation of 49.1%.     

Demonstrating accuracy of the already proposed protocol for structure elucidation of cyclodextrin inclusion complexes by validation using quantitative ROESY analysis

In this study, we attempt to ascertain the accuracy of the structures determined using our previously developed method and hence the accuracy of our method. In the present report, we have taken the guest molecule cetirizine (CTZ) and the host molecules are α-cyclodextrin (α-CD) and β-cyclodextrin (β-CD). Structures with good accuracy were elucidated using a productive fusion of experimental and computational methods. We performed molecular mechanics studies (MM) in light of experimental ROESY studies, followed by molecular dynamics studies (MD). The results from these studies were analyzed using quantitative ROESY analysis to determine the final accurate structures of the complexes. The accuracy of these structures was tested using density functional theory (DFT) that is an accurate method for structure determination. DFT studies were carried out using the functionals B3LYP and M06L with def-TZVP basis set and similarly quantitative ROESY analysis was performed for the obtained structures. The ROESY intensities of the structures obtained from MM and MD studies, were compared with ROESY intensities of the structures obtained from DFT studies. Calculated ROESY intensities of the structures obtained from B3LYP functional are comparable, with intensities of structures obtained from MM and MD studies, but M06L functional showed poor results. In addition to the accuracy of MM and MD studies, low computational cost and less time input make it good method for structural studies for CD inclusion complexes.

     

Conjugate heat transfer within a concentric annulus filled with micropolar fluid

This paper investigates numerically the conjugate heat transfer in an annulus between two concentric cylinders. The annulus contains micropolar fluid and is heated isothermally from its inner wall. The effect of Rayleigh number, thickness of inner wall, inner wall-fluid thermal conductivity ratio, and material parameters of micropolar fluid on heat transfer rate within the annulus has been investigated. The study has shown that for low Rayleigh number regimes and for thermal conductivity of the inner wall greater than that of the fluid, the increase of inner wall thickness increases the heat transfer rate through the annulus and vice versa. While for convection dominating regimes Ra ≥ 10⁴ the increase of inner wall thickness decreases the heat transfer rate. Moreover, the study has shown that for fixed geometrical and flow parameters the heat transfer decreases in case of micropolar fluids in comparison with that of Newtonian fluids.     

Simultaneous operation of dibenzothiophene hydrodesulfurization and methanol reforming reactions over Pd promoted alumina based catalysts

In the current study simultaneous reactions of hydrodesulfurization(HDS) of dibenzothiophene(DBT) and reforming of methanol in a micro-autoclave reactor were studied over bi-metallic(Co-Mo/Al2O3 and Ni-Mo/Al2O3) and tri-metallic(Pd-Co-Mo/Al2O3 and Pd-Ni-Mo/Al2O3) catalyst systems which were prepared by incipient impregnation method.In situ hydrogen utilization and low Pd loadings were the major targets of this study.For comparison purpose,catalytic activity was separately determined for both the methanol reforming and HDS of DBT reactions as well.Ni based catalysts were confirmed with better activity than Co ones for both the reactions with Pd promoted ones ranking at the top i.e.Pd-Ni-Mo/Al2O3 > Ni-Mo/Al2O3 > Pd-Co-Mo/Al2O3 > Co-Mo/Al2O3 where Pd-Ni-Mo/Al2O3 showed 91% DBT conversion at 380 ℃ and 12 h reaction time.Some of the selected organic additives on catalytic activity were tested for their effect toward HDS reaction which was unique with close relation to their chemical nature.Reaction products were quantitatively and qualitatively analyzed via HPLC and GC-MS techniques respectively which helped in elucidating reaction mechanism.     

Jeffrey fluid flow due to curved stretching surface with Cattaneo-Christov heat flux

The two-dimensional (2D) motion of the Jeffrey fluid by the curved stretching sheet coiled in a circle is investigated. The non-Fourier heat flux model is used for the heat transfer analysis. Feasible similarity variables are used to transform the highly nonlinear ordinary equations to partial differential equations (PDEs). The homotopy technique is used for the convergence of the velocity and temperature equations. The effects of the involved parameters on the physical properties of the fluid are described graphically. The results show that the curvature parameter is an increasing function of velocity and temperature, and the temperature is a decreasing function of the thermal relaxation time. Besides, the Deborah number has a reverse effect on the pressure and surface drag force.     

Hybrid Quinoline-Thiosemicarbazone Therapeutics as a New Treatment Opportunity for Alzheimer’s Disease‒Synthesis,In Vitro Cholinesterase Inhibitory Potential and Computational Modeling Analysis

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder and the leading cause of dementia worldwide. The limited pharmacological approaches based on cholinesterase inhibitors only provide symptomatic relief to AD patients. Moreover, the adverse side effects such as nausea, vomiting, loss of appetite, muscle cramps, and headaches associated with these drugs and numerous clinical trial failures present substantial limitations on the use of medications and call for a detailed insight of disease heterogeneity and development of preventive and multifactorial therapeutic strategies on urgent basis. In this context, we herein report a series of quinoline-thiosemicarbazone hybrid therapeutics as selective and potent inhibitors of cholinesterases. A facile multistep synthetic approach was utilized to generate target structures bearing multiple sites for chemical modifications and establishing drug-receptor interactions. The structures of all the synthesized compounds were fully established using readily available spectroscopic techniques (FTIR, ¹H- and ¹³C-NMR). In vitro inhibitory results revealed compound 5b as a promising and lead inhibitor with an IC₅₀ value of 0.12 ± 0.02 μM, a 5-fold higher potency than standard drug (galantamine; IC₅₀ = 0.62 ± 0.01 μM). The synergistic effect of electron-rich (methoxy) group and ethylmorpholine moiety in quinoline-thiosemicarbazone conjugates contributes significantly in improving the inhibition level. Molecular docking analysis revealed various vital interactions of potent compounds with amino acid residues and reinforced the in vitro results. Kinetics experiments revealed the competitive mode of inhibition while ADME properties favored the translation of identified inhibitors into safe and promising drug candidates for pre-clinical testing. Collectively, inhibitory activity data and results from key physicochemical properties merit further research to ensure the design and development of safe and high-quality drug candidates for Alzheimer’s disease.     

Preparation,Characterization, and Pharmacological Investigation of Withaferin-A Loaded Nanosponges for Cancer Therapy; In Vitro,In Vivo and Molecular Docking Studies

The rapidly growing global burden of cancer poses a major challenge to public health and demands a robust approach to access promising anticancer therapeutics. In parallel, nanotechnology approaches with various pharmacological properties offer efficacious clinical outcomes. The use of new artificial variants of nanosponges (NS) as a transporter of chemotherapeutic drugs to target cells has emerged as a very promising tool. Therefore, in this research, ethylcellulose (EC) NS were prepared using the ultrasonication assisted-emulsion solvent evaporation technique. Withaferin-A (WFA), an active ingredient in Withania somnifera, has been implanted into the nanospongic framework with enhanced anticancer properties. Inside the polymeric structure, WFA was efficiently entrapped (85 ± 11%). The drug (WFA) was found to be stable within polymeric nanosponges, as demonstrated by Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC) studies. The WFA-NS had a diameter of 117 ± 4 nm and zeta potential of −39.02 ± 5.71 mV with a polydispersity index (PDI) of 0.419 ± 0.073. In addition, scanning electron microscopy (SEM) revealed the porous surface texture of WFA-NS. In vitro anticancer activity (SRB assay) results showed that WFA–NS exhibited almost twice the anticancer efficacy against MCF-7 cells (IC₅₀ = 1.57 ± 0.091 µM), as quantified by flow cytometry and comet tests. Moreover, fluorescence microscopy with DAPI staining and analysis of DNA fragmentation revealed apoptosis as a mechanism of cancer cell death. The anticancer activity of WFA-NS was further determined in vivo and results were compared to cisplatin. The anticancer activity of WFA-NS was further investigated in vivo, and the data were consistent to those obtained with cisplatin. At Day 10, WFA-NS (10 mg/kg) significantly reduced tumour volume to 72 ± 6%, which was comparable to cisplatin (10 mg/kg), which reduced tumour volume to 78 ± 8%. Finally, the outcomes of molecular modeling (in silico) also suggested that WFA established a stable connection with nanosponges, generating persistent hydrophobic contacts (polar and nonpolar) and helping with the attractive delayed-release features of the formulation. Collectively, all the findings support the use of WFA in nanosponges as a prototype for cancer treatment, and opened up new avenues for increasing the efficacy of natural product-derived medications.