Frictional Wear and Thermal Fatigue Properties of Die Steel after Ultrasound-Assisted Alloying.

The surface layer of 8407 die steel was strengthened using the combination of ultrasonic surface rolling and high-energy ion implanting in the present work. The strengthened layer was then characterized via microstructure observation, composition analysis, and hardness test. After that, the frictional wear and thermal fatigue properties of high-energy ion implanting specimens and composite-reinforced specimens were compared. Results show that the pretreatment of specimens with ultrasonic surface rolling causes grain refinement in the material surface, which promotes the strengthening effect of high-energy ion implanting. The wear volume of composite-reinforced specimens at medium and high frequencies is reduced by about 20%, and the wear resistance of these specimens is significantly improved with a lower friction coefficient and wear volume at moderate and high frequencies in alternating load friction experiments. Meanwhile, the thermal fatigue crack depth of composite-reinforced specimens is reduced by about 47.5%, which effectively prevents the growth of thermal cracks in the surface, thus improving the curing ability of the implanted elements. Therefore, composite strengthening of the mold steel surface is conducive to improving the cycle life, ensuring accuracy, effectively hindering the expansion of thermal cracks, and saving the cost of production.

The anti-cancer effect of metoclopramide on triple-negative breast cancer cells.

Triple-negative breast cancer (TNBC) is the most aggressive type of breast cancers. Chemotherapy is the most important therapeutic option for TNBC, and chemotherapy-induced nausea and vomiting (CINV) is inevitable. Metoclopramide is a good and cost-effective therapeutic option for chemotherapy-induced nausea and vomiting. However, it is not commonly used in breast cancer because it can increase serum prolactin levels by blocking dopamine D2 receptor. This study aimed at elucidating the effect of metoclopramide on triple-negative breast cancer, MDA-MB-231 cells were treated with various concentrations of metoclopramide, the cell proliferation was detected by MTT method, the apoptosis rate was detected by Annexin V/PI double staining method, the expression change of death-related protein was detected by Western Blot. We found that metoclopramide inhibits cell proliferation and induces cell apoptosis of MDA-MB-231 in a concentration-dependent manner, and the Bcl family was involved in this process.