Enhancing continuous-flow reactions compression-molding of solid catalysts and dilutants in packed-bed systems.

In this study, we present an improved packed-bed system designed for continuous-flow reactions using platinum (Pt)-black powder and silica gel (SiO). The Pt-leaching from the reaction column is suppressed compression-molding of the Pt and SiO. Scanning electron microscopy results and particle-size distribution analysis demonstrate that crushed and downsized SiO is effective in suppressing outflow.

Characteristic terahertz absorption spectra of paramylon and paramylon-ester compounds.

Paramylon is a long-chain polysaccharide, composed of glucose units connected via β-(1,3) glycosidic bonds, that spontaneously forms a three-strand helical bundle. Paramylon-esters can be made by partially or fully replacing saccharide chain hydroxide groups with carboxylic functional groups, such as stearoyl (CH(CH)CO) and palmitoyl (CH(CH)CO). The paramylon-ester with carboxylic acids has superior characteristics, including high thermal resistance, stability and transparency under visible light, which are necessary for thermoplastic applications.

Molecular vibration and Boson peak analysis of glucose polymers and ester via terahertz spectroscopy.

Complex permittivity spectra were obtained herein by performing broadband terahertz (THz) spectroscopy on cellulose, paramylon, and paramylon ester. Absorption peaks observed for cellulose and paramylon at approximately 3 THz are attributed to hydrogen bonds. In addition, a broad absorption peak around 2 THz was observed for all the polymers, demonstrating a general feature of polymer glasses derived from weak interatomic van der Waals forces.

Regioselective Diels-Alder reaction to open-cage ketolactam derivatives of C.

Open-cage ketolactam fullerenes reacted with dienes on the rim of the orifice both regio- and stereoselectively. Unequivocal evidence for the structure of the Diels-Alder adduct was provided by 2D INADEQUATE C NMR studies on C enriched material, as well as via DFT-GIAO calculations. The theoretical calculations successfully model the regioselective and the endo stereoselective reaction, predicting molecular orbital control along with a repulsive steric interaction between the substituents on the nitrogen atom and those on the diene.

Efficacy of middle meningeal artery embolization in the treatment of refractory chronic subdural hematoma.

Background: There are no established treatment procedures for repeatedly recurring chronic subdural hematoma (CSH). In this study, we discussed the efficacy of middle meningeal artery (MMA) embolization in preventing recurrence of CSH.

Methods: We performed superselective angiography of MMA in four patients who suffered from repeated recurrence of CSH.