RESUMO
The depolymerization process of PET by glycolysis into BHET monomer is optimized in terms of reaction temperature and time, by carrying out the process under pressure to be faster for reducing the energy required. Almost pure BHET has been obtained by working in a pressure reactor at 3 bar both at 220 and 180 °C after short reaction times, while for longer ones a mixture of oligomers and dimers is obtained. Depending on the potential application required, the obtention of different reaction products is controlled by adjusting reaction temperature and time. The use of a pressure reactor allows work at lower temperatures and shorter reaction times, obtaining almost pure BHET. To the best of our knowledge, except for microwave-assisted procedures, it is the first time in which pure BHET is obtained after such short reaction times, at lower temperatures than those usually employed.
RESUMO
Thirteen patients with treatment-resistant major depression were given venlafaxine, at doses ranging from 150 mg to 375 mg, combined with ECT. Propofol was used as an anesthetic. Ten of 13 (76.9%) were considered responsive to combined ECT-venlafaxine treatment, and positive responses were not associated with venlafaxine doses. An asystole episode was observed in 4 patients; these patients had received significantly higher doses of venlafaxine (P<0.01). Treatment seems to be safe at venlafaxine doses <300 mg/day. At higher doses, with propofol used as anesthetic, the possibility of asystole cannot be ruled out. A possible additive effect of high-dose venlafaxine and propofol-blocking sodium channels are discussed.