The influence of Sc addition on microstructure and tensile mechanical properties of Mg-4.5Sn-5Zn alloys

The microstructure and tensile properties of the as-cast and as-rolled Mg-4.5Sn-5Zn alloys by adding various Sc content were investigated.Improvement of the tensile properties in as-cast Sc-containing alloys is attributed to the grain refinement and modification of secondary phase morphology.Three types of precipitates,namely spherical Mg2Sn,rod-like MgZn and Sc-rich phases were dispersed in the matrix of the Sc added M g-4.5Sn-5Zn alloys after hot rolling deformation.In addition,weakening and deflecting of the basal texture in as-rolled alloys were found and were attributed to Sc addition.Further increasing the Sc addition rate to 0.4 wt.%,however,resulted in the clustering of the Sc-rich phases and was found to reduce the tensile properties of the alloy,especially the elongation.The as-rolled Mg-4.5Sn-5Zn-0.3Sc alloy exhibits an optimum combination of tensile properties.The ultimate tensile strength,yield strength and elongation are 293.0MPa,164.2Mpa and 21.5%,respectively,and the elongation is about 68%higher than that of Sc-free alloy.

Acrylamide induces HepG2 cell proliferation through upregulation of miR-21 expression

Acrylamide, a potential carcinogen, exists in carbohydrate-rich foods cooked at a high temperature. It has been reported that acrylamide can cause DNA damage and cytotoxicity. The present study aimed to investigate the potential mechanism of human hepatocarcinoma HepG2 cell proliferation induced by acrylamide and to explore the antagonistic effects of a natural polyphenol curcumin against acrylamide via miR-21. The results indicated that acrylamide(≤100μmol/L) significantly increased HepG2 cell proliferation and miR-21 expression. In addition, acrylamide reduced the PTEN expression in protein level, while induced the expressions of p-AKT, EGFR and cyclin D1. The PI3 K/AKT inhibitor decreased p-AKT protein expression and inhibited the proliferation of HepG2 cells. In addition, curcumin effectively reduced acrylamide-induced HepG2 cell proliferation and induced apoptosis through the expression of miR-21. In conclusion, the results showed that acrylamide increased HepG2 cell proliferation via upregulating miR-21 expression, which may be a new target for the treatment and prevention of cancer.

Design of concise robust control for longitudinal motionof YuKun

With the rapid development of the shipping industry,the safety and comfort of ship transportation have been paid more and more attention,and the pitch and heave motion of ships are the most serious factors.In this paper,the longitudinal motion mathematical model of YuKun is esta b lished.By assigning the zero-pole to the left half-plane and using the properties of the symmetric matrix,the shaping weighting functions matrix is designed to stabilize the multi-input multi-output(MIMO)system of YuKun.Finally,a new concise robust controller is designed using the steady output of the shaped system.The simulation results show that under the control of the concise robust controller,the pitch angle and heave of YuKun decrease by 79.9% and 86.2%,respectively.Theoretical analysis and simulation results show that the concise robust controller has a good control effect on the longitudinal motion of YuKun,and is simple and easy to use,with clear engineering significance.