Process for preparation of hydroperoxides

The invention relates to a process for preparing hydroperoxides from their corresponding hydrocarbons which comprises oxidizing said hydrocarbons, particularly ethylbenzene, with an oxygen containing gas in the presence of a catalyst comprising a cyclic imide compound and a compound selected from the group consisting of an alkaline metal compound or mixture thereof

Cytoarchitecture of the dorsal lateral geniculate nucleus in the rabbit

The cytoarchitecture and morphometry of the neurons in the a, sector of the dorsal lateral geniculate nucleus of the rabbit have been studied. The preparation techniques used were those of Golgi-Adams and Klüver-Barrera. Our method was to subdivide the a, sector into three zones (superior, media1 and inferior) and then to cut each zone along the horizontal, transverse and saggital planes in order to obtain precise measurements and descriptions of the neurons whatever their orientation. Differences exist in both the size and distribution of neurons in the inferior zone of the a, sector compared to the other two

Morphological changes induced by colchicine in the chick optic cup in early stages of development. A stereological study

In this study chick embryo optic cups at HH stage 13 of development were analyzed under normal conditions and after inoculation with colchicine for 1, 2, 4, and 8 h. Several changes were seen after these periods of treatment: 1) modifications of the structure, with thicker regions in the cup and a general decrease in the total volume according to the duration of exposure to the drug (about 4 times less than normal, 5,035 x lo3 ym3 vs 1,334 x lo3 ym3 after 8 h of treatrnent); 2) enlargement of the ventricular cavity and its closure, due to failure of approximation of retina1 and pigmentary layers; 3) failure of lens development, with delay and impairment of pit formation and deformation of al1 structures; lens volume was less than normal (about 4 times less, 2,148 x 103 pm3 vs 658 x lo3 pm3. after 8 h of treatment); 4) a general segregation of the cells making up the structure, principally in the more active proliferating zones. The local alterations found are describe

CATALYTIC EPOXIDATION OF CYCLOHEXENE WITH TERT-BUTYLHYDROPEROXIDE USING AN IMMOBILIZED MOLYBDENUM CATALYST

This work describes the synthesis of molybdenum complexes immobilized on a silica support and their performance in the epoxidation reaction of cyclohexene using tert-butylhydroperoxide (TBHP) as the oxidizing agent. The catalyst synthesis included solubilization of variable amounts of bis-oxomolybdenum (VI) acetylacetonate precursor in different solvents such as tetrahydrofuran (THF), ethanol, THF/water and ethanol/water mixtures and contact with the silica support. Characterization techniques demonstrated that the nature of the incorporated molybdenum species depends markedly on the solvent employed. If the solvent employed is an ethanol:water mixture, physical adsorption of the Mo-species onto the support surface occurs; however, when THF is used as the solvent (THF catalyst series), molybdenum is grafted on the silica surface via chemical bonding with the surface hydroxyl groups of silica. Specifically, these latter catalysts show similar performance to that of the homogeneous catalyst, although long-term experiments showed deactivation by leaching of the active phase.Peer reviewe