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TiO2 nanoparticles doped with different concentrations of Zr4+ ions were prepared by the sol–gel method and annealed at different temperatures. X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and high resolution transmission electron microscopy (HRTEM) techniques were used to investigate the existing states and doping mechanism of dopants as well as the phase transition of the Zr4+-doped TiO2 samples. It was revealed that the doping behavior of introduced Zr4+ ions was closely related to the doping concentration. The Zr4+ ions would replace the lattice Ti4+ ions directly in substitutional mode at a certain annealing temperature. Moreover, if the concentration of doped Zr4+ ions is high enough, excess Zr4+ ions would form ZrTiO4 on the surface of TiO2. In addition, the phase transition temperature from anatase to rutile increases significantly after doping Zr4+ ions, due to their larger electropositivity and radius than those of Ti4+ ions. Our results may afford a better understanding on the doping mechanism and aid in the preparation of Zr-doped TiO2 with high photoelectric performance.

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Nitrogen and zirconium co-doped TiO2 (TiO2-N-x%Zr) photocatalysts were synthesized via a sol-gel method. The existing states of the dopants (N and Zr) and their corresponding band structures were investigated via XRD, Raman, BET, XPS, TEM, FT-IR, UV-vis DRS, and PL techniques. It was found that N existed only as a surface species (NOx) and Zr(4+) was doped in a substitutional mode; the doping of Zr(4+) ions and modification of N extended the absorption into the visible region and inhibited the recombination of electrons and holes. Moreover, the excess Zr(4+) ions existed as the ZrTiO4 phase when the content of Zr was sufficiently high, which could also contribute to the separation of the charge carriers. Therefore, the TiO2-N-x%Zr samples show enhanced visible-light photocatalytic activity compared with single-doped TiO2. These results offer a paradigm for the design and fabrication of optoelectronic functional materials such as solar cells and photocatalysts.

Developing bio-based flame retardants according to a green and simple strategy has drawn extensive attention recently. Hence, a biomass-derived, flame-retardant, latent curing agent (IMPA) was synthesized via the neutralization between imidazole and phytic acid in water at room temperature and was applied for single-component epoxy resin (EP). The results indicate that the shelf life of the resultant EP (EP/IMPA) increases from <1 day of the control single-component EP to 10 days at room temperature. Meanwhile, EP/IMPA features a fast curing rate at modest temperature (80–150 °C), and its gel time at 100 °C is only 14 min. Notably, EP/IMPA achieves superior flame retardancy with a limiting oxygen index of 34.7% and UL-94 V-0 rating. The peak heat release rate (PHRR), total heat release (THR), and total smoke production (TSP) of EP/IMPA are reduced by 43.0%, 31.9%, and 31.5% compared with the control sample. The enhanced fire safety is ascribed to the flame-retardant function of IMPA in both gaseous and condensed phases. Hence, this work provides a green and feasible method to create bio-based, flame-retardant, latent curing agents for one-component epoxy systems.

Total hip arthroplasty

ObjectiveTo evaluate the efficacy and safety of CyberKnife® treatment for locally-advanced pancreatic cancer (LAPC).MethodsThe efficacy of CyberKnife® treatment was analyzed in 59 LAPC patients treated between October 2006 and September 2014. The median tumor volume was 27.1 mL (13.0–125.145 mL). The median prescribed dose was 45 Gy (35–50 Gy), delivered in 5 fractions (3–8 fractions). The overall survival (OS) rates and freedom from local progression (FFLP) rates were estimated using the Kaplan–Meier survival curve.ResultsThe median follow-up for all patients was 10.9 months (3.2–48.7 months) and 15.6 months (3.9–37.6 months) among surviving patients. The median OS was 12.5 months, and the 1-year and 2-year survival rates were 53.9% and 35.1%, respectively. The 1-year FFLP rate was 90.8% based on the computed tomography (CT) evaluation. Grade 1–2 acute and late-stage gastrointestinal (GI) reactions were observed in 61% of the patients. One patient experienced grade 3 toxicity.ConclusionExcellent clinical efficacy was obtained after treatment of LAPC using CyberKnife®, with minimal toxicity.