Wire arc additive manufacturing (WAAM) offers a potential approach to fabricate large-scale magnesium alloy components with low cost and high efficiency, although this topic is yet to be reported in literature. In this study, WAAM is preliminarily applied to fabricate AZ31 magnesium. Fully dense AZ31 magnesium alloy components are successfully obtained. Meanwhile, to refine grains and obtain good mechanical properties, the effects of pulse frequency (1, 2, 5, 10, 100, and 500 Hz) on the macrostructure, microstructure and tensile properties are investigated. The results indicate that pulse frequency can result in the change of weld pool oscillations and cooling rate. This further leads to the change of the grain size, grain shape, as well as the tensile properties. Meanwhile, due to the resonance of the weld pool at 5 Hz and 10 Hz, the samples have poor geometry accuracy but contain finer equiaxed grains (21 μm) and exhibit higher ultimate tensile strength (260 MPa) and yield strength (102 MPa), which are similar to those of the forged AZ31 alloy. Moreover, the elongation of all samples is above 23%.

Objective To assess the performance of pretreatment 18 F-fluorodeoxyglucose positron emission tomography/computed tomography ( 18 F-FDG PET/CT) radiomics features for predicting EGFR mutation status in patients with non-small cell lung cancer (NSCLC). Patients and Methods We enrolled total 173 patients with histologically proven NSCLC who underwent preoperative 18 F-FDG PET/CT. Tumor tissues of all patients were tested for EGFR mutation status. A PET/CT radiomics prediction model was established through multi-step feature selection. The predictive performances of radiomics model, clinical features and conventional PET-derived semi-quantitative parameters were compared using receiver operating curves (ROCs) analysis. Results Four CT and two PET radiomics features were finally selected to build the PET/CT radiomics model. Compared with area under the ROC curve (AUC) equal to 0.664, 0.683 and 0.662 for clinical features, maximum standardized uptake values (SUV max ) and total lesion glycolysis (TLG), the PET/CT radiomics model showed better performance to discriminate between EGFR positive and negative mutations with the AUC of 0.769 and the accuracy of 67.06% after 10-fold cross-validation. The combined model, based on the PET/CT radiomics and clinical feature (gender) further improved the AUC to 0.827 and the accuracy to 75.29%. Only one PET radiomics feature demonstrated significant but low predictive ability (AUC = 0.661) for differentiating 19 Del from 21 L858R mutation subtypes. Conclusions EGFR mutations status in patients with NSCLC could be well predicted by the combined model based on 18 F-FDG PET/CT radiomics and clinical feature, providing an alternative useful method for the selection of targeted therapy.

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Thin films of Nd3+-∕V5+-cosubstituted bismuth titanate, (Bi3.15Nd0.85)(Ti3−xVx)O12 (BNTV), were fabricated by chemical solution deposition technique. For different vanadium contents (x=0.03, 0.06, and 0.09), the crystallized phase and electrical properties of the films were investigated using x-ray diffraction, polarization hysteresis loops, leakage current-voltage, and capacitance butterfly loops. The authors found that increasing vanadium content leads to the decrease of coercive field and the increase of capacitance. The film of vanadium content x=0.09 exhibits fatigue-free and excellent leakage current characteristics with I=5.99×10−9A at applied voltage of 3V, which is much lower than that of Bi3.15Nd0.85Ti3O12 thin film [X. S. Gao and J. Wang, Thin Solid Films 515, 1683 (2006)]. The frequency dependence of the remanent polarization for the BNTV thin film was discussed.