Normal- and reversed-phase high-performance thin-layer chromatography methods for the simultaneous determination of remogliflozin etabonate and metformin hydrochloride antidiabetic drugs in bulk and tablet formulation

JPC – Journal of Planar Chromatography – Modern TLC - Two new, simple, fast, and sensitive methods, normal- and reversed-phase high-performance thin-layer chromatography (NP-HPTLC and...     

Generalization of waving-plate theory to multiple interacting swimmers

Early research in aerodynamics and biological propulsion was dramatically advanced by the analytical solutions of Theodorsen, von Kármán, Wu and others. While these classical solutions apply only to isolated swimmers, the flow interactions between multiple swimmers are relevant to many practical applications, including the schooling and flocking of animal collectives. In this work, we derive a class of solutions that describe the hydrodynamic interactions between an arbitrary number of swimmers in a two-dimensional inviscid fluid. Our approach is rooted in multiply-connected complex analysis and exploits several recent results. Specifically, the transcendental (Schottky–Klein) prime function serves as the basic building block to construct the appropriate conformal maps and leading-edge-suction functions, which allows us to solve the modified Schwarz problem that arises. As such, our solutions generalize classical thin aerofoil theory, specifically Wu's waving-plate analysis, to the case of multiple swimmers. For the case of a pair of interacting swimmers, we develop an efficient numerical implementation that allows rapid computations of the forces on each swimmer. We investigate flow-mediated equilibria and find excellent agreement between our new solutions and previously reported experimental results. Our solutions recover and unify disparate results in the literature, thereby opening the door for future studies into the interactions between multiple swimmers.     

Catalytic reduction of 4-nitrophenol using synthesized and characterized CoS@MorphcdtH/CoS@4-MPipzcdtH nanoparticles

CoS@MorphcdtH NPs and CoS@4-MPipzcdtH NPs were synthesized by precipitation method involving three mechanisms: inclusion, occlusion, and adsorption. The synthesized NPs were characterized with the help of UV-Vis spectroscopy, FESEM-EDAX, powder x-ray diffraction, TEM, ESIMS, TG/DSC analysis. The morphology of the CoS@MorphcdtH NPs and CoS@4-MPipzcdtH NPs were hexagonal and rectangular, and the particles were in the range 7–12 nm. UV–visible spectral measurements showed surface plasmon resonance at 320 nm–340 nm with band gap of 3.65 eV–3.86 eV. The catalytically active CoSNPs called were investigated for the reduction of 4-nitrophenol (4-NP) via hydrogenation using sodium borohydride (NaBH₄) as a reducing agent. Both the CoS NPs successfully reduced 4-NP to 4- aminophenol (4-AP) in a short time, catalytic performances are almost unchanged for the first five cycles. Herein, we report the preparation and characterizations of efficient active CoS NPs consisting carbodithioic acid framework as a support/capping material, along with catalytic property.     

Lewis acidic organoboron polymers

We have developed a highly efficient new method for the introduction of Lewis acidic boron centers into the side chains of organic polymers. Our methodology involves three steps: (i) the controlled polymerization of a functional monomer, (ii) the exchange of the functional group for Lewis acidic boron centers, and (iii) the fine-tuning of the Lewis acidity of the individual centers through substituent exchange reactions with nucleophiles. This approach gives access to a family of new well-defined organoboron polymers including moderately Lewis acidic poly(arylboronates) and the first examples of highly Lewis acidic fluorinated triarylborane polymers.