Rapid sonochemical synthesis of MCM-41 type benzene-bridged periodic mesoporous organosilicas.

Benzene-bridged periodic mesoporous organosilicas (PMOs) with the MCM-41 were synthesized by a rapid sonochemical process via co-condensation of tetraethoxysilane (TEOS) and 1,4-bis(triethoxysilyl) benzene (BTEB) under basic conditions within a few minutes using cetyltrimethylammoniumbromide (CTMABr) as a structure-directing agent. The molar ratio of the silicon precursors and the synthesis time were varied in order to investigate their influence on the structural ordering of the materials. The characteristics of the materials were evaluated by X-ray diffraction (XRD), N2-sorption, transmission electron microscopy (TEM) and solid-state NMR spectroscopy.

Synthesis, bifunctionalization, and remarkable adsorption performance of benzene-bridged periodic mesoporous organosilicas functionalized with high loadings of carboxylic acids.

Highly ordered benzene-bridged periodic mesoporous organosilicas (PMOs) that were functionalized with exceptionally high loadings of carboxylic acid groups (COOH), up to 80 mol % based on silica, have been synthesized and their use as adsorbents for the adsorption of methylene blue (MB), a basic dye pollutant, and for the loading and release of doxorubicin (DOX), an anticancer drug, is demonstrated. These COOH-functionalized benzene-silicas were synthesized by the co-condensation of 1,4-bis(triethoxysilyl) benzene (BTEB) and carboxyethylsilanetriol sodium salt (CES), an organosilane that contained a carboxylic acid group, in the presence of non-ionic oligomeric surfactant Brij 76 in acidic medium. The materials thus obtained were characterized by a variety of techniques, including powder X-ray diffraction (XRD), nitrogen-adsorption/desorption isotherms, TEM, and (13)C and (29)Si solid-state NMR spectroscopy.

The misplacement of external ventricular drain by freehand method in emergent neurosurgery.

External ventricular drain (EVD) placement is one of the most basic and common neurosurgical procedure which most was performed by young neurosurgical trainees. This study is conducted to determinate the safe and accuracy of EVD placement by freehand method. About 129 EVD placements were evaluated in this study.

Ependymal cyst with hemorrhage in the cerebellopontine angle.

Ependymal cysts are rare intracranial neoplasms. These lesions occur in the cerebral parenchyma, subarachnoid space, and juxtaventricular, intraspinal, and intramedullary regions. They occur extremely rarely in the cerebellopontine angle (CPA).