Five Ti-rich β+α″+α′ Ti–Zr–Nb–Ta biomedical medium-entropy alloys with excellent mechanical properties and corrosion resistance were developed by considering thermodynamic parameters and using the valence electron concentration formula. The results of this study demonstrated that the traditional valence electron concentration formula for predicting phases is not entirely applicable to medium-entropy alloys. All solution-treated samples with homogeneous compositions were obtained at a low temperature (900 °C) and within a short period (20 min). All solution-treated samples exhibited low elastic moduli ranging from 49 to 57 GPa, which were significantly lower than those of high-entropy alloys with β phase. Solution-treated Ti65–Zr29–Nb3–Ta3 exhibited an ultra-high bending strength (1102 MPa), an elastic recovery angle (>30°), and an ultra-low elastic modulus (49 GPa), which are attributed to its α″ volume fraction as high as more than 60%. The pitting potentials of all samples were higher than 1.8 V, and their corrosion current densities were lower than 10–5 A/cm3 in artificially simulated body fluid at 37 °C. The surface oxide layers on Ti65–Zr29–Nb3–Ta3 comprised TiO2, ZrO2, Nb2O5, and Ta2O5 (as discovered through X-ray photoelectron spectroscopy) and provided the alloy with excellent corrosion and pitting resistance.
BackgroundAdvanced inoperable hepatocellular carcinoma (HCC) conferring a grave prognosis may benefit from yttrium-90 (90Y) radioembolization.MethodsThirty patients with advanced inoperable HCC including those with any lesion >8 cm in maximal diameter or multiple bi-lobar lesions (totally more than five lesions), or portal vein thrombosis treated with radioembolization were reviewed. Treatment efficacy and safety were evaluated. Univariate and multivariate analyses were performed for identifying potential prognostic factors.ResultsAfter a median follow-up of 18.3 months, the response rate was 30.0%, and the disease control rate was 50.0%. Median overall progression-free survival (PFS) and overall survival (OS) were 3.3 months and 13.2 months, respectively. Longer median PFS was noted in those who had transarterial chemoembolization before radioembolization (7.3 months vs 3.1 months; P=0.021) and duration of alfafeto protein (AFP) response ≥6 months (11.8 months vs 3.0 months; P<0.001). Longer median OS was also revealed in those without portal vein thrombosis (17.1 months vs 4.4 months; P=0.015) and those whose duration of AFP response was ≥6 months (21.2 months vs 8.6 months; P=0.001). Seventeen patients (56.7%) developed treatment-related complications including five (16.7%) grade 3 events. Multivariate analysis revealed that treatment responders (P=0.001) and duration of AFP response ≥6 months (P=0.006) were prognostic of PFS, whereas the absence of portal vein invasion (P=0.025), treatment responders (P=0.010), and duration of AFP response ≥6 months (P=0.001) were prognostic of OS.Conclusion90Y radioembolization is an alternative treatment with a promising outcome for poor-risk advanced inoperable HCC.
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