The total synthesis of ganglioside 2, an analogue of the ganglioside Hp-s1 (1) which displays neuritogenic activity toward the rat pheochromocytoma cell line PC-12 cell in the presence of nerve growth factor (NGF) with an effect (34.0%) greater than that of the mammalian ganglioside GM 1 (25.4%), was accomplished by applying a chemoselective-activation glycosylation strategy. Moreover, we also demonstrate that the synthesized ganglioside 2 exhibited neuritogenic activity toward the human neuroblastoma cell line SH-SY5Y without the presence of NGF.

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Herein, the evaluation of four commercial alkoxysilanes and two laboratory synthesized novel diethoxysilacycloalkanes as external donors towards propylene polymerization has been done.

The present work deals with the free axisymmetric vibrations of circular sandwich plates with core of linearly varying thickness. The face sheets are treated as membranes of equal thickness and the core is assumed to be solid as well as moderately thick. The plate is assumed to be symmetric about the middle surface. Due to linear thickness variation in the core, the face sheets take the shape of conical shell and because of this the face sheet membrane forces contribute to the bending and transverse shear of the core of sandwich plate. The effect of transverse shear and rotatory inertia has been retained in the core. The equations of motion for such a plate have been derived by Hamilton’s energy principle. The frequency equations for three different boundary conditions have been obtained by employing differential quadrature method. The effect of various plate parameters such as taper parameter, thickness of the core at the center, face thickness on the natural frequencies has been studied. Comparison of results has been made.

An efficient [3 + 2]/[4 + 2] or double [4 + 2] cycloaddition strategy has been established for the synthesis of heterocyclic systems under mild conditions. The reaction pathway is governed by the nature of reaction partner. Several dihydrofurocoumarin, furopyranocoumarin, dihydrofuran, dihydrobenzopyran, and dihydrobenzofuran derivatives were obtained as single diastereomers from cyclic or acyclic enol ethers and styrenes. This one-pot transformation constructed C-C and C-O bonds and generated molecular complexity by domino/tandem process to produce the heterocyclic systems in good yields. The ring closure of domino protocol was highly stereoselective and resulted in the formation of cis-fused systems.

Sodium potassium niobate (KNN) (K 0.5 Na 0.5 NbO 3 ) nanopowder with a mean particle size of about 20 -30 nm was synthesized by wet chemical route using Nb 2 O 5 as Nb source. A solution of K, Na and Nb cations was prepared, which resulted in a clear gel after the thermal treatment. Phase analysis, microstructure and morphology of the powder were determined by X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Field Emission Scanning Electron Microscopy (FESEM). The obtained gel was first analyzed by Thermo Gravimetric Analyzer (TGA) and Differential Scanning Calorimetry (DSC), and then calcined at different temperatures of 400˚C, 500˚C, 600˚C and 700˚C. The X-Ray Diffraction (XRD) patterns of the synthesized samples confirmed the formation of the orthorhombic crystal phase of K 0.5 Na 0.5 NbO 3 at 500˚C, a temperature significantly lower than that typically used in the conventional mixed oxide route. The process developed in this work is convenient to realize the mass production of KNN nanopowders at low cost and suitable for various industrial applications.

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