Surface and bulk morphology of cold-crystallized poly(ethylene terephthalate)

The morphology/habit of crystals of cold-crystallized poly(ethylene terephthalate) (PET) has been evaluated using scanning and transmission electron microscopy and using atomic force microscopy. The combination of different preparation and analysis techniques allowed assessing the structure at the nanometer scale of films of PET at both the surface and the bulk. It is found that crystals formed on heating the amorphous glass to a temperature higher than the glass transition temperature are of lamellar shape in the bulk and almost isometric habit at the surface. This finding is explained by different rates of nucleation/crystallization in the bulk and at the surface, being supported by the observation of nanometer-scale surface heterogeneities after quenching PET to ambient temperature before crystallization was initiated by heating.     

vic‐Tricarbonyl Compounds of Quinolines: Analogues of Ninhydrin: A Short Review

Derivatives of ninhydrin are extensively used in the field of forensic sciences as important latent fingerprint reagents. Many works have been performed upon their synthesis and reactivity, but there are many spaces to work on the compounds of quinoline‐2,3,4(1H)‐triones—analogues of ninhydrin, in both dimensions: synthesis and reactivity, and according to the best of our knowledge, not a single detailed or short compiled article has been published for these compounds. This review briefly summarizes the chemistry of quinoline‐2,3,4(1H)‐triones.     

Control of combined convection in a nanofluid-filled lid-driven closed space via rectangular bar in the presence of magnetic field

Journal of Thermal Analysis and Calorimetry - In the present study, a computational work has been done to see the heat transfer, fluid flow and temperature distribution in a lid-driven cavity due...     

Mixed convection and entropy production in a nanofluid-filled closed space with inclined magnetic field

Journal of Thermal Analysis and Calorimetry - A computational analysis has been performed to study the impact of magnetic field on entropy generation due to mixed convective nanofluid flow with top...     

Effects of inclined magnetic field on mixed convection in a nanofluid filled double lid-driven cavity with volumetric heat generation or absorption using finite element method

A computational analysis has been performed on mixed convection in a double sided lid-driven cavity in the presence of volumetric heat generation or absorption. Effects of inclined magnetic field are also studied. The governing parameters are solved via Galerkin weighted residual finite element method in space and the Crank–Nicolson in time. Governing parameters are nanoparticle volume fraction (0.0?≤???≤?0.04), Richardson number (0.01?≤?Ri?≤?10), internal heat generation or absorption parameter $(?10\le q\le 10),$ inclination angle of magnetic field (0°?≤?γ?≤?90°) and Hartmann number (0?≤?Ha?≤?100). It is observed that the highest heat transfer is obtained in case of the maximum value of heat absorption. As a further finding, heat transfer decreases with increasing of Hartmann number and increases with increasing of nanoparticle volume fraction.     

In Silico Analysis of PORD Mutations on the 3D Structure of P450 Oxidoreductase

Cytochrome P450 oxidoreductase (POR) is a membrane-bound flavoprotein that helps in transferring electrons from its NADPH domain to all cytochrome P450 (CYP450) enzymes. Mutations in the POR gene could severely affect the metabolism of steroid hormones and the development of skeletal muscles, a condition known as Cytochrome P450 oxidoreductase deficiency (PORD). PORD is associated with clinical presentations of disorders of sex development, Antley and Bixler’s syndrome (ABS), as well as an abnormal steroid hormone profile. We have performed an in silico analysis of POR 3D X-ray protein crystal structure to study the effects of reported mutations on the POR enzyme structure. A total of 32 missense mutations were identified, from 170 PORD patients, and mapped on the 3D crystal structure of the POR enzyme. In addition, five of the missense mutations (R457H, A287P, D210G, Y181D and Y607C) were further selected for an in-depth in silico analysis to correlate the observed changes in POR protein structure with the clinical phenotypes observed in PORD patients. Overall, missense mutations found in the binding sites of POR cofactors could lead to a severe form of PORD, emphasizing the importance of POR cofactor binding domains in transferring electrons to the CYP450 enzyme family.     

Magnetohydrodnamics nanofluid flow of shaped nanoparticles over a porous stretching wall and slip effect

In this study, we analyze the magnetohydrodynamic flow of magnetite-engine oil nanofluid in the presence of nonidentical shaped nanoparticles subject to the porous medium and velocity slip effect. Energy analysis is carried out with the Ohmic heating and thermal radiation impacts. The system of partial differential equations are transformed into the system of ordinary differential equations using similarity variable. The Hamilton–Crosser model is used. The exact solutions for the momentum and heat transport analysis are found. The impact of various emerging parameters on the velocity and temperature profiles are analyzed by graphs. Furthermore, the local skin friction and heat transfer rate are examined graphically. It is examined that the velocity field increases with an increment in the magnitude of ϕ and L. An increase in the value of Hartman number enhancing the temperature profile.     

Synthesis,characterization and antibacterial activity of palladium(II) bromide complexes of thioamides; X-ray structure of [Pd(tetramethylthiourea)<Subscript>4</Subscript>]Br<Subscript>2</Subscript>

Palladium(II) bromide complexes of thioamides having the general formulae [PdL₂Br₂] and [PdL₄]Br₂ where L = Thiourea (Tu), Methylthiourea (Metu), Dimethylthiourea (Dmtu), Tetramethylthiourea (Tmtu), Imidazolidine-2-thione (Imt), Mercaptopyridine (Mpy), Mercaptopyrimidine (Mpm) and Thionicotinamide (Tna) were prepared by reacting K₂[PdCl₄] with KBr and the corresponding thioamides. The complexes were characterized by elemental analysis, IR and NMR spectroscopy, and one of them, [Pd(Tmtu)₄]Br₂ (1) by X-ray crystallography. The crystal structure of 1 shows a square-planar coordination environment around the Pd(II) atoms with the average cis and trans S–Pd–S bond angles of 90.0° and 180.0°, respectively. The synthesized complexes were screened for antibacterial effects, and the results showed that the complexes exhibit significant activities against both gram positive and gram negative bacteria.     

Biological and phytochemical studies on Capparis decidua (Forssk) Edgew from Cholistan desert

Abstract

The present work deals with the biological and phytochemical studies on Capparis decidua (Forssk) Edgew from Cholistan desert of Pakistan. Aerial and floral parts of C. decidua were collected and dried under shade. Powdered materials of each part of C. decidua were extracted with methanol separately, followed by phytochemical studies. Hexane fraction of aerial parts of the C. decidua obtained after solvent-solvent extraction was purified through repeated column chromatography by increasing order of polarity. Four compounds were purified and identified as simiarenol (1), lupeol (2), taraxerol (3) and β-sitosterol (4). Simiarenol and lupeol were isolated for the first time from genus Capparis. The structures of these compounds were established by comparing the spectroscopic data (¹H NMR, ¹³C NMR, IR, UV & Mass spectrometry) reported in literature. The structure of 1 was further confirmed by XRD analysis. Anti-bacterial activities of crude methanolic extracts were determined against 13 bacterial strains (MIC 250-1000?μg/mL). α-Glucosidase and urease inhibitory activities of pure compounds were also determined. Compounds 1, 2 and 4 showed α-glucosidase inhibition with IC₅₀ at 96.12?±?0.12, 65.28?±?0.13 and 128.14?±?0.17?μM, respectively.