Corrosion behavior of the friction-stir-welded joints of 2A14-T6 aluminum alloy

The corrosion behavior of friction-stir-welded 2A14-T6 aluminum alloy was investigated by immersion testing in immersion exfoliation corrosion（EXCO） solution. Electrochemical measurements（open circuit potential, potentiodynamic polarization curves, and electrochemical impedance spectroscopy）, scanning electron microscopy, and energy dispersive spectroscopy were employed for analyzing the corrosion mechanism. The results show that, compared to the base material, the corrosion resistance of the friction-stir welds is greatly improved, and the weld nugget has the highest corrosion resistance. The pitting susceptibility originates from the edge of Al-Cu-Fe-Mn-Si phase particles as the cathode compared to the matrix due to their high self-corrosion potential. No corrosion activity is observed around the θ phase（Al2Cu） after 2 h of immersion in EXCO solution.

Notoginsenoside R1 attenuates breast cancer progression by targeting CCND2 and YBX3

Background:Breast cancer(BC)is a common malignancy with highly female incidence.So far the function of notoginsenoside R1(NGR1),the extract from Panax notoginseng,has not been clearly elucidated in BC.Methods:Optimal culture concentration and time of NGR1 were investigated by cell counting kit-8 assay.Cell proliferation ability was measured by colony formation assays.Transwell assay was used to detect the effect of NGR1 on cell migration and invasion.The apoptosis rate of cells between each group was measured by TUNEL assay.Results:NGR1 treatment has an inhibitory efect on proliferation,migration,invasion,and angiogenesis and a stimulating effect on cell cycle arrest and apoptosis of Michigan Cancer Foundation-7(MCF-7)cells.The 50%growth inhibitory concentration for MCF-7 cells at 24 h was 148.9 mmol/L.The proportions of MCF-7 cells arrested in the G0/G1 phase were 36.94+6.78%,45.06士5.60%,and 59.46+5.60%in the control group,75,and 150 mmol/L groups,respectively.Furthermore,we revealed that NGR1 treatment attenuates BC progression by targeted downregulating CCND2 and YBX3 genes.Additionally,YBX3 activates phosphatidylinositol 3-phosphate kinase(PI3K)/protein kinase B(Akt)signaling pathway by activating kirsten rat sarcoma viral oncogene,which is an activator of the PI3K/Akt signaling pathway.Conclusion:These results suggest that NGR1 can act as an efficacious drug candidate that targets the YBX3/PI3K/Akt axis in patients with BC.