Electronic charge distribution in the intermetallic compound MnHg

The Electron Density Distribution (EDD) of the Mn and Hg atoms in MnHg has been elucidated for the first time using the statistical approach MEM (Maximum Entropy Method). Reported powder X‐ray data have been used for the present analysis. Presently, MEM studies are gaining momentum because of the feasibility of mapping the refined electron densities with very high accuracy, well resolved and clear electron density distributions obtainable from this method, etc. Moreover, the MEM results resemble very nearly the true structure/electron densities unlike the conventional Fourier methods, which give biased information due to many reasons, the major one being the series termination error. In the present analysis, the bonding between Mn and Hg, and the electron content for different radii of the two atoms has been investigated. The thermal vibration of the two atoms has also been analyzed and reported. The thermal parameter of Hg has been more accurately determined than that of Mn, which is in consistent with the electron density distribution of the atoms.     

Characterization of best uniform coapproximation

This paper deals with Kolmogorov criterion for best uniform coapproximation and strongly unique best uniform coapproximation. Some relations between best uniform approximation and best uniform coapproximation are obtained. Some equalities and best uniform coapproximation are connected.     

Thermal Non-Equilibrium Porous Convection with Heat Generation and Density Maximum

Linear stability criterion for the onset of natural convection in a fluid saturated porous medium with uniform internal heat generation and density maximum is determined. The porous medium is not in local thermal equilibrium (LTE) and we follow a two-field model for the energy equation. It is found that both the heat generation and density maximum have an additive effect in advancing the onset condition. In general the destabilising effect of density maximum increases for large values of the fluid heat generation parameter. This effect becomes prominent even for small values of the fluid heat generation parameter when the flow is of Darcy type and LTE is not valid.     

Discovery of Novel Coumarin Derivatives as Potential Dual Inhibitors against α-Glucosidase and α-Amylase for the Management of Post-Prandial Hyperglycemia via Molecular Modelling Approaches

Coumarin derivatives are proven for their therapeutic uses in several human diseases and disorders such as inflammation, neurodegenerative disorders, cancer, fertility, and microbial infections. Coumarin derivatives and coumarin-based scaffolds gained renewed attention for treating diabetes mellitus. The current decade witnessed the inhibiting potential of coumarin derivatives and coumarin-based scaffolds against α-glucosidase and α-amylase for the management of postprandial hyperglycemia. Hyperglycemia is a condition where an excessive amount of glucose circulates in the bloodstream. It occurs when the body lacks enough insulin or is unable to correctly utilize it. With open-source and free in silico tools, we have investigated novel 80 coumarin derivatives for their inhibitory potential against α-glucosidase and α-amylase and identified a coumarin derivative, CD-59, as a potential dual inhibitor. The ligand-based 3D pharmacophore detection and search is utilized to discover diverse coumarin-like compounds and new chemical scaffolds for the dual inhibition of α-glucosidase and α-amylase. In this regard, four novel coumarin-like compounds from the ZINC database have been discovered as the potential dual inhibitors of α-glucosidase and α-amylase (ZINC02789441 and ZINC40949448 with scaffold thiophenyl chromene carboxamide, ZINC13496808 with triazino indol thio phenylacetamide, and ZINC09781623 with chromenyl thiazole). To summarize, we propose that a coumarin derivative, CD-59, and ZINC02789441 from the ZINC database will serve as potential lead molecules with dual inhibition activity against α-glucosidase and α-amylase, thereby discovering new drugs for the effective management of postprandial hyperglycemia. From the reported scaffold, the synthesis of several novel compounds can also be performed, which can be used for drug discovery.     

A green solid acid catalyst 12-tungstophosphoric acid H3[PW12O40] supported on g-C3N4 for synthesis of quinoxalines

Research on Chemical Intermediates - A green Keggin-type heteropoly-12-tungstophosphoric acid, (H3[PW12O40].12H2O) supported on graphitic carbon nitride g-C3N4 (HPW/g-C3N4-40), was developed for...     

Enhancing the Aspirin Loading and Release Efficiency of Silver Oxide Nanoparticles Using Oleic Acid-based Bio-Surfactant from Enteromorpha intestinalis

This study is an attempt to improve the loading and release potential of silver oxide nanoparticles (AgO NPs) using Oleic acid based bio-surfactant isolated from Enteromorpha instestinalis. The isolated Oleic acid based bio-surfactant was characterized using GC–MS, NMR, and HPLC. The AgO NPs were then surface-functionalized with the bio-surfactant and analyzed using XRD, HR-TEM/SAED, DLS, UV–Vis, and FTIR spectroscopy to evaluate the loading of aspirin and functional groups responsible for loading. The model drug Aspirin that has depreciated bio-availability due to poor solubility was used to test the drug carrier efficiency of the AgO NPs after the surface-functionalization. The loading of aspirin was increased by up to 80% in bio-surfactants than PEG-coated NPs (72%) at a 1:1 ratio (Aspirin/NP). The drug release profile of aspirin was evaluated by dialysis at different acidic conditions (pH 1.2, 6.8, and 7.4) and the active release of aspirin was observed in pH 6.8 and bio-surfactant produced better release than PEG and commercial tablet in all the pH conditions. To identify the mechanism of release from the carrier, the release kinetics was studied using zero-order, first-order, Higuchi's, and Korsmeyer Peppas equations and found that the release was time-dependent and non-fickian.     

Alcohol molecular interaction studies on stair phosphorene nanosheets: a first-principles approach

Structural Chemistry - In this proposed work, we examined the interaction properties of alcohol viz. methanol and ethanol molecules on stair phosphorene nanosheet (stair-PNS) based on the...     

Exploring the structure,binding mode,flexibility and toxicity nature for Sinefungin molecule: a theoretical approach

Sinefungin (SFN) is an antiviral agent of dengue (DENV) and Zika (ZIKV) viruses with IC₅₀ values of 0.63 and 1.18 µM, respectively. The ADMET properties of SFN revealed that the SFN molecule can be used as an oral drug due to its good solubility nature. The molecular docking analysis of SFN molecule with RNA capping site of DENV and ZIKV NS5 MTase was performed. From this, the SFN-DENV MTase was found to be the best, based on binding energy (??7.56 kcal/mol) and intermolecular interactions. The geometrical parameters of the optimized conformation and docked conformations of SFN molecule are compared which indicated that the intermolecular interactions lead to the modifications of SFN conformation in active site. The molecular electrostatic potential map of SFN depicts the possible nucleophilic and electrophilic locations present in the molecule. The HOMO–LUMO based electronic properties such as electron affinity (A), electrophilicity (ω), electronegativity (χ) and global hardness (η) were calculated to determine the stability and toxicity of SFN molecule. Fukui function and NBO analysis of SFN were also computed.

     

Effect of annealing on phase composition,structural and magnetic properties of Sm-Co based nanomagnetic material synthesized by sol-gel process

Sm-Co based nanomagnetic material was synthesized by means of a Pechini-type sol-gel process. In this method, a suitable gel-precursor was prepared using respective metal salts and complexing agent such as citric acid. The gel-precursor was dried at 300 °C and then subjected to various reductive annealing temperatures: 350, 500 and 600 °C. The nanopowders so obtained were characterized for their structure, phase composition and magnetic properties. FT-IR studies on the gel-precursor showed the binding of metal cations with the citrate molecules in the form of metal-citrate complex. The gel-precursor, which was annealed at 350 °C showed the presence of both meta-stable cobalt carbide (Co₂C, Co₃C) and Co₃O₄ phases; while the sample annealed at 500 °C indicated the sign of SmCo₅ phase. Upon increasing the reductive annealing temperature to 600 °C, crystalline phase such as fcc-Co and Sm₂C₃ were formed prominently. FE-SEM analysis revealed the change in sample morphology from spherical to oblate spheres upon increasing the annealing temperature. VSM measurements demonstrated ferromagnetic nature at room temperature for all the nanopowders obtained irrespective of their after reductive annealing temperature.