Agglomeration−aggregation and leaching properties of mechanically activated chalcopyrite

The effect of mechanical activation on the granulometric parameters,microstructure,and leaching efficiency of chalcopyrite was evaluated,and the occurrence/transition of agglomeration and aggregation was discussed.The results showed that in 8 h of milling treatment,the agglomeration and the microstructure did not affect each other.However,with prolonging milling time,the crystallite size tended to reach a saturation value,and the stagnating microstructural changes led to the replacement of agglomeration by aggregation.The leaching results indicated that the mechanical activation can strongly enhance the reactivity of chalcopyrite and the hindering effect of aggregation on leaching was considerably greater than that of agglomeration.Consequently,after 8 h of milling,the maximum Cu leaching rate of 80.13%was achieved after 4 h of acid leaching.

Aspirin Enhances the Protective Effect of Progesterone on Trophoblast Cell from Oxidative Stress and Apoptosis

Objective:Clinically,low-dose aspirin and progesterone are frequently used to prevent pregnancy loss.We investigated the effect of these drugs on the biological behavior of human extravillous trophoblasts in vitro.Methods:HTR-8/SVneo cells were cultured in vitro and treated with different concentrations of aspirin and progesterone.The proliferation,invasion,and apoptosis of HTR-8/SVneo cells were assessed using a cell counting Kit-8 assay,Matrigel Transwell assay,and Hoechst staining,respectively.Reverse transcriptase polymerase chain reaction was used to verify the expression of related genes.Reactive oxygen species(ROS)levels were detected using the 2,7-dichlorofluorescin diacetate assay.Results:Low-dose aspirin alone,progesterone alone,or aspirin plus progesterone upregulated the proliferation and invasion and decreased the apoptosis of HTR-8/SVneo cells.Moreover,the expression of marker of proliferation Ki-67(MKI67),matrix metalloproteinases 2(MMP2),and MMP9 was increased.In addition,low-dose aspirin plus progesterone exerted stronger anti-apoptosis effects than low-dose aspirin and progesterone alone.Interestingly,aspirin upregulated the expression of progesterone receptor(PGR).Treatment with hydrogen peroxide(H_(2)O_(2))promoted ROS production in HTR-8/SVneo cells;however,low-dose aspirin plus progesterone significantly restricted H_(2)O_(2)-mediated ROS production and apoptosis in HTR-8/SVneo cells.Conclusions:These data suggest that low-dose aspirin and progesterone promote proliferation and invasion and cooperatively reduce oxidative stress and apoptosis in trophoblasts in vitro.These results may provide an experimental basis for the combined application of aspirin and progesterone to prevent unexplained recurrent spontaneous miscarriage,especially in patients with trophoblast dysfunction.