Biomethanation of syngas at high CO concentration in a continuous mode.

Syngas from pyrolysis/gasification process is a mixture of CO, CO2 and H2, which could be converted to CH4, so called syngas biomethanation. Its development is obstructed due to the low productivity and CO inhibition. The aim of this study was to demonstrate the feasibility of using syngas as the only carbon source containing high CO concentration (40%) for biomethanation. Lab-scale thermophilic bioreactor inoculated with anaerobic sludge was operated continuously for over 900 h and the shift of microbial structure were investigated. Results showed that thermophilic condition was suitable for syngas biomethanation and the microbes could adapt to high CO concentration. Higher processing capacity of 12.6 m3/m3/d was found and volumetric methane yield of 2.97 m3/m3/d was observed. These findings could strengthen the theoretical basis of syngas biomethanation and support its industrialization in the future.

Salvage Therapy for Brain Arteriovenous Malformations After Failure of Gamma Knife Stereotactic Radiosurgery.

OBJECTIVE: The aim of this study was to investigate delayed complications in patients with brain arteriovenous malformation (BAVM) after Gamma Knife stereotactic radiosurgery and to present the salvage therapy experiences of patients with BAVM with radiation-induced changes (RICs) or intracranial hemorrhage (ICH). METHODS: This cohort consisted of 44 patients with BAVM who underwent failed GKRS between 2000 and 2015. These patients were further divided into an RIC group (23 patients) and an ICH group (21 patients) based on their post-GKRS complications. The patients' characteristics, treatment strategies, and long-term outcomes were analyzed. The modified Rankin Scale was used to assess the neurologic status of each patient. RESULTS: In our study, the marginal dose and radiosurgery-based arteriovenous malformation score were not significantly different between the 2 groups. Craniotomy was performed in 26 patients (9 patients with ICH and 17 patients with RICs), and histologic examination showed cavernous angioma changes in 6 patients. In addition, 6 patients underwent repeat radiosurgery in the ICH group, and 7 patients used bevacizumab in the RIC group. Thirty patients showed good outcomes at the last follow-up (modified Rankin Scale score <3). CONCLUSIONS: Salvage therapy for patients with BAVM should be performed based on the latency period and lesion characteristics of each individual. Prompt treatment and a longer follow-up are recommended to achieve good clinical outcomes.