Three-point bending experiments were performed on as-cast and annealed samples of Zr 52.5 Cu 17.9 Ni 14.6 Al 10 Ti 5 (Vit105) bulk metallic glasses over a wide range of temperatures varying from room temperature (293 K) to liquid nitrogen temperature (77 K). The results demonstrated that the free volume decrease due to annealing and/or cryogenic temperature can reduce the propensity for the formation of multiple shear bands and hence deteriorate plastic deformation ability. We clearly observed a sharp ductile-to-brittle transition (DBT), across which microscopic fracture feature transfers from micro-scale vein patterns to nano-scale periodic corrugations. Macroscopically, the corresponding fracture mode changes from ductile shear fracture to brittle tensile fracture. The shear transformation zone volume, taking into account free volume, temperature and strain rate, is proposed to quantitatively characterize the DBT behavior in fracture of metallic glasses.

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In this paper, Gd-promoted Co3O4 catalysts were prepared via a facile coprecipitation method for low-temperature catalytic N2O decomposition. Due to the addition of Gd, the crystallite size of Co3O4 in the Gd0.06Co catalyst surprisingly decreased to 4.9 nm, which is much smaller than most additive-modified Co3O4 catalysts. This huge change in the catalyst’s textural structure endows the Gd0.06Co catalyst with a large specific surface area, plentiful active sites, and a weak Co–O bond. Hence, Gd0.06Co exhibited superior activity for catalyzing 2000 ppmv N2O decomposition, and the temperature for the complete catalytic elimination of N2O was as low as 350 °C. Meanwhile, compared with pure Co3O4, E a decreased from 77.4 to 46.8 kJ·mol–1 and TOF of the reaction increased from 1.16 × 10–3 s–1 to 5.13 × 10–3 s–1 at 300 °C. Moreover, Gd0.06Co displayed a quite stable catalytic performance in the presence of 100 ppmv NO, 5 vol % O2, and 2 vol % H2O.

Primary oral mucosal malignant melanoma (POMM) is uncommon. Its biological behavior is more aggressive than that of cutaneous malignant melanoma. Its site-specific prognostic factors and optimal management have not been determined yet. Retrospective POMM case analysis from peer-reviewed publications in the PubMed and Embase electronic database from January 1984 to December 2013, in which therapy and outcome data were available, was performed. A total of 151 primary cases were extracted from 39 peer-reviewed English literatures. The study population includes 63 males and 88 females with a medium age of 61 years. The treatment protocols include surgery alone (18%), radiotherapy alone (14%), surgery plus radiotherapy (14%), surgery plus chemotherapy (31%), as well as surgery plus chemoradiotherapy (15%) and chemoradiotherapy (8%). The male patients have a higher risk for metastasis than the female patients do (odds ratio [OR]; 3.41, P = 0.021). The POMM originating from specialized mucosa was associated with increased risk for tumor recurrence and mortality (OR, 4.03, P = 0.001; OR, 2.03, P = 0.031, respectively). The patients who had surgery-based multiple therapy have a significantly longer survival compared with those who had surgery alone and those who had no surgical treatment (P = 0.000). The age of 60 years or younger (hazard ratio [HR], 4.69; P = 0.000), nonsurgical treatment (HR, 12.838; P = 0.000), and surgery alone (HR, 1.517; P = 0.001) were independent adverse prognostic factors for overall survival. Taken together, the study results suggest that surgery-based multiple therapy is the most effective treatment protocol. The age of 60 years, nonsurgical treatment, and surgery alone were independent adverse prognostic factors for overall survival.

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