RESUMO
In this work, the effect of gamma irradiation emitted by Cobalt 60 source has been investigated for the degradation of hydroxychloroquine (HCQ). The monitoring of the gamma irradiation treatment of HCQ aqueous solutions was followed by UV-visible, chemical oxygen demand, total organic carbon (TOC) and LC/MS analyses. Effects of several important parameters such as concentration, dose rate and pH on the degradation efficiency were studied then evaluated. Achieved results showed that % TOC removal efficiency of 98.5 was obtained after 8 kGy absorbed dose which warrants HCQ mineralization. The process was found to be more efficient when the initial pollutant concentration was low, with higher dose rate and at neutral pH. Furthermore, HCQ degradation kinetic study revealed a pseudo-first-order kinetic. Additionally, based on by-products identified by LC/MS, a degradation mechanistic schema mediated through hydroxyl radicals generated by water radiolysis has been proposed. Finally, in order to check the potential industrial application viability the energy consuming was evaluated.
RESUMO
Vermian epidermoid cyst developing in the fourth ventricle is very rare. We report a case observed in a 24-year-old man, who presented severe headache, dizziness and a blurred vision following head injury. Examination revealed a discrete gait disturbance. Cerebral CT-scan showed a large hypodense lesion of the posterior fossa without contrast enhancement. MRI demonstrated the vermian location of this lesion which displaced the roof of the fourth ventricle upward and the brainstem forward. A suboccipital approach allowed total removal of a well-encapsulated epidermoid cyst, non adherent to the floor of the fourth ventricle. The postoperative course was uneventful.
