Morphology and formation mechanism of ceria nanoparticles by spray pyrolysis

Ceria-based materials are used in industrial applications such as catalyst supports, carbon monoxide reduction catalysts, and solid oxide fuel cell electrolytes. Various applications require different morphological particles. The ceria particles with various morphologies from the precursors of cerium(III) acetate hydrate, cerium(IV) nitrate hydrate, and cerium(IV) ammonium nitrate were prepared by spray pyrolysis (SP) because SP has the potential for simple and continuous process. The precursor behaviors and the particle morphologies were characterized by thermogravimetric analysis and by transmission electron microscopy. Four main morphologies of solid spherical, hollow spherical with a single pore, hollow concave, and hollow spherical with multiple pores were observed. The experimental results suggest that the morphological formation mechanism is highly correlated with the factors of precursor solubilities, solvent evaporation rates (droplet diameters), and precursor melting temperatures. In addition, total concentrations of cerium(III) in the ceria particles from various precursors were examined using X-ray photoelectron spectroscopy.     

Adlay Seed (Coix lacryma-jobi L. var. Ma-yuen Stapf.) Ethanolic Extract Fractions and Subfractions Induce Cell Cycle Arrest and Apoptosis in Human Breast and Cervical Cancer Cell Lines

The antitumor effects of Coix lacryma-jobi L. var. ma-yuen Stapf. (adlay seed) ethanolic extract have been increasingly shown. This study aimed to investigate the beneficial effects of both the fractions and subfractions of adlay seed ethanolic extract on the human breast (MCF-7) and cervical (HeLa) cancer cell lines, as well as exploring their possible mechanisms of action. The ethanolic extracts were obtained from different parts of adlay seed, including AHE (adlay hull extract), ATE (adlay testa extract), ABE (adlay bran extract) and PAE (polished adlay extract). The results of a 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl- tetrazolium bromide (MTT) assay showed that AHE-Ea and ATE-Ea showed significant growth inhibitory effects in a dose-dependent manner. The results also showed that the AHE-Ea-K, AHE-Ea-L, ATE-Ea-E and ATE-Ea-F subfractions inhibited cell proliferation, induced cell cycle arrest in the G0/G1 phase and decreased CDK4/Cyclin D1 protein expression. Finally, the extract activated caspase-3 activity and PARP protein expression, which induced MCF-7 and HeLa cell apoptosis. We then used liquid chromatography–mass spectrometry (LC/MS) to identify the potential active components., Quercetin showed an anticancer capacity. In conclusion, the AHE-Ea-K, AHE-Ea-L, ATE-Ea-E and ATE-Ea-F subfractions showed antitumor effects through the inhibition of MCF-7 and HeLa cell line viability, as well as inducing apoptosis and cell cycle arrest.