A Tentative Modeling Study of the Effect of Wall Reactions on Oxidation Phenomena

This paper gives details of a tentative modeling study that investigates the inhibiting effect of internal reactor walls treated with acid..

Osteosarcoma of the mobile spine†

Background The aims of this analysis were to investigate features and outcome of high-grade osteosarcomas of the mobile spine. Patients and methods Since 1977, 20 Cooperative Osteosarcoma Study Group patients had a diagnosis of high-grade osteosarcomas of the mobile spine and were included in this retrospective analysis of patient-, tumor- and treatment-related variables and outcome. Results The median age was 29 years (range 5-58). Most frequent tumor sites were thoracic and lumbar spine. All but three patients had nonmetastatic disease at diagnosis. Treatment included surgery and chemotherapy for all patients, 13 were also irradiated. Eight patients failed to achieve a macroscopically complete surgical remission (five local, one primary metastases, two both), six died, two are alive, both with radiotherapy. Of 12 patients with complete remission at all sites, three had a recurrence (two local, one metastases) and died. The median follow-up of the 11 survivors was 8.7 years (range 3.1-22.3), 5-year overall and event-free survival rates were 60% and 43%. Age <40 years, nonmetastatic disease at diagnosis and complete remission predicted for better overall survival (OS, P < 0.05). Conclusions Osteosarcomas of the mobile spine are rare. With complete resection (and potentially radiotherapy) and chemotherapy, prognosis may be comparable with that of appendicular osteosarcoma

Clinical effectiveness of Enneking appropriate versus Enneking inappropriate procedure in patients with primary osteosarcoma of the spine: a systematic review with meta-analysis

Purpose Primary osteosarcoma of the spine is a rare osseous tumour. En bloc resection, in contrast to intralesional resection, is the only procedure able to provide Enneking appropriate (EA) margins, which has improved local control and survival of patients with primary osteosarcoma of the spine. The objective of this study is to compare the risk of local recurrence, metastases development and survival in patients with primary osteosarcoma of the spine submitted to Enneking appropriate (EA) and Enneking inappropriate (EI) procedures. Methods A systematic search was performed on EBSCO, PubMed and Web of Science, between 1966 and 2018, to identify studies evaluating patients submitted to resection of primary osteosarcoma of the spine. Two reviewers independently assessed all reports. The outcomes were local recurrence, metastases development and survival at 12, 24 and 60 months. Results Five studies (108 patients) were included for systematic review. These studies support the conclusion that EA procedure has a lower local recurrence rate (RR 0.33, 95% CI 0.17-0.66), a lower metastases development rate (RR 0.39, 95% CI 0.17-0.89) and a higher survival rate at 24 months (RR 1.78, 95% CI 1.24-2.55) and 60 months (RR 1.97, 95% CI 1.14-3.42) of follow-up; however, at 12 months, there is a non-significant difference. Conclusions EA procedure increases the ratio of remission and survival after 24 months of follow-up. Multidisciplinary oncologic groups should weigh the morbidity of an en bloc resection, knowing that in the first year the probability of survival is the same for EA and EI procedures. Graphic abstract These slides can be retrieved under Electronic Supplementary Material

Degradation effects at the methanol inlet, outlet and center region of a stack MEA operated in DMFC

Ru dissolution is one of the key issues in direct methanol fuel cells (DMFC). A used DMFC stack membrane electrode assembly (MEA)was analyzed using different analytical techniques like X-ray diffraction (XRD). X-ray absorption spectroscopy (XAS), transmission electron microscopy (TEM) and EDX and different regions probed in the process. Catalyst powder from e.g. like methanol inlet, outlet and center were investigated and compared with the as-received commercial electrocatalyst and the pristine MEA after manufacture. The large oxidized ruthenium fraction in the anode catalyst was found to play a significant role in particle growth and ruthenium dissolution. Crossover ruthenium from the anode side was found to be dispersed everywhere in the cathode in its oxidized form, and thus can have a significant effect on the oxygen reduction activity (ORR). Although with XRD no significant structural changes were observed for the different regions of the MEA, TEM and EDX analysis showed the preferential precipitation of the Ru at the methanol outlet. (C) 2011 Elsevier B.V. All rights reserved