A Brønsted Acidic Ionic Liquid as an Efficient and Selective Catalyst System for Bioderived High Molecular Weight Poly(ethylene 2,5-furandicarboxylate).

Green synthesis of bioderived high-molecular-weight poly(ethylene 2,5-furandicarboxylate) (PEF) over metal-free catalysts is a significant challenge. This study focuses on PEF prepared from ethylene glycol and 2,5-furandicarboxylic acid (FDCA) through a direct esterification method with ecofriendly metal-free ionic liquids (ILs) as catalysts. The catalytic activities of a series of imidazolium cations in the presence of various anions are systematically investigated and found to be mainly governed by the anions. Among the ILs studied, 1-ethyl-3-methylimidazolium tetrafluoroborate ([C2 MIM]BF4 ) is identified as the best catalyst, showing excellent catalytic activity, selectivity, and stability, even at low catalyst loadings (0.1 mol % w.r.t. FDCA). Optimization of the polymerization parameters enables [C2 MIM]BF4 -catalyzed production of PEF with a high number-average molecular weight (Mn =5.25×104  g mol-1 ). The relationship between Brønsted acidity and catalytic activity is also investigated and the results show that the trend in catalytic activity is in good agreement with that in Brønsted acidity, as determined by the Hammett method. Additionally, on the basis of experimental results and density functional theory calculations, an electrophilic activation mechanism induced by hydrogen bonds is proposed. This strategy of adjustable acidity and anion structure in ILs provides an opportunity to develop other ILs for bio-based polyesters through green synthesis pathways.

Chemoradiotherapy in combination with radical surgery is associated with better outcome in cervical cancer patients.

OBJECTIVES: To retrospectively assess the influence of radical surgery following concurrent chemoradiotherapy (CCRT) on outcomes in cervical cancer (CC) patients. METHODS: Patients diagnosed with cervical squamous cell carcinoma or adenocarcinoma (FIGO stages IB2 to IIB) at the Yinbin Second People's Hospital between September 2008 and September 2013, were included in this study. Patients were classified into 2 groups based on the treatment received: surgery group (CCRT plus radical surgery) and non-surgery groups (CCRT only). In addition to clinical information, inter-group differences with respect to local control rate (LCR), local recurrence rate (LRR), metastasis rate, overall survival (OS), progress free survival(PFS) and complications were assessed. RESULTS: A total of 314 patients were included in the analysis. Parametrial invasion, pelvic lymph node metastasis, tumor diameter > 4 cm and presence of residual disease were risk factors for recurrence in the non-surgery group. In patients with risk factors, radical surgery significantly improved their clinical outcome. The 3-year/5-year LCR in the surgery and non-surgery groups was 88.3%/87.4% and 82.3%/77.5%, respectively (P = 0.04). The 3-year/5-year OS rate in the two groups was 87.1%/81.7% and 72.8%/67.3%, respectively (P = 0.001). The 3-year/5-year LRR in the two groups were 11.7%/12.6% and 17.7%/22.5%, respectively (P = 0.04). The metastasis rates in the two groups were 19.9% and 24.8%, respectively (P = 0.09). CONCLUSIONS: Surgery following CCRT could improve overall survival and progressfree survival. Radical surgery following CCRT appears to confer significant benefits including an increase in LCRs and decrease in LRR in CC patients with risk factors.