Composition and Microstructure of Biocompatible and pH-Sensitive Copolymers Prepared by a Free Solvent ARGET ATRP

Controlled/living radical polymerizations enable the synthesis of functional polymers with well-defined compositions and architectures. In this paper, we propose the usage of the ARGET ATRP technique to produce copolymers of MMA and DMAEMA. The feed composition was changed systematically to modulate the final composition of the copolymer. The absence of additional organic solvent (bulk polymerization), the use of low amounts of metal catalyst and the reduction of purification steps are the main advantages with respect to a traditional ATRP

Effect of Fe3+ Doping in the Photocatalytic Properties of BaSnO3 Perovskite

<div><p>In the last ten years, stannates with perovskite structure have been tested as photocatalysts. In spite of the ability of perovskite materials to accommodate different cations in its structure, evaluation of doped stannates is not a common task in the photocatalysis area. In this work, Fe3+ doped BaSnO3 was synthesized by the modified Pechini method, with calcination between 300 and 800ºC/4 h. The powder precursor was characterized by thermogravimetry after partial elimination of carbon. Characterization after the second calcination step was done by X-ray diffraction, Raman spectroscopy and UV-visible spectroscopy. Materials were tested in the photocatalytic discoloration of the Remazol Golden Yellow azo dye under UVC irradiation. Higher photocatalytic efficiency was observed under acid media. As no meaningful adsorption was observed at this condition we believe that an indirect mechanism prevails. Fe3+ doping decreased the band gap and favored the photocatalytic reaction, which may be assigned to the formation of intermediate levels inside the band gap.</p></div

The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study

AimThe SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery.MethodsThis was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin.ResultsOverall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P ConclusionOne in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease