Platinum nanoparticles (PtNP) exhibit remarkable antioxidant activity. There is growing evidence concerning a positive relationship between oxidative stress and bone loss, suggesting that PtNP could protect against bone loss by modulating oxidative stress. Intragastric administration of PtNP reduced ovariectomy (OVX)-induced bone loss with a decreased level of activity and number of osteoclast (OC) in vivo. PtNP inhibited OC formation by impairing the receptor activator of nuclear factor-κB ligand (RANKL) signaling. This impairment was due to a decreased activation of nuclear factor-κB and a reduced level of nuclear factor in activated T-cells, cytoplasmic 1 (NFAT2). PtNP lowered RANKL-induced long lasting reactive oxygen species as well as intracellular concentrations of Ca2+ oscillation. Our data clearly highlight the potential of PtNP for the amelioration of bone loss after estrogen deficiency by attenuated OC formation.

In this study, Cu-TiC nanocomposites were fabricated from a mixture of Cu and 5÷15% wt. TiC powders by ball milling and subsequent spark-plasma sintering. The morphology of Cu-TiC nanocomposite powders were observed by field emission scanning electron microscopy. Only characteristic peaks of Cu and TiC phases were detected from X-ray diffraction patterns of milled powder mixture. Sintered compacts showed a highly densified compacts (∼95% relative density) while retaining fine grains in the matrix. The hardness, wear resistance, and fracture surface of the sintered specimens were also investigated.

A Gas atomization process is well known method to produce spherical metallic powders. In this paper, we produced spherical stainless (SUS) 439L powders using the gas atomization process. The SUS 439L alloy powders were prepared with the SUS 439L scraps which come from after mechanical machining (press and cutting) processes. The as-prepared gas atomized powders were observed by visual identification method. Internal microstructure of the powers was observed by optical microscopy. Size and size distribution and shape of the powders were observed by field emission scanning electron microscope and laser partial size analyzer. Phase of the powers was analyzed by X-ray diffraction. Full densified samples were produced by conventional sintering and spark plasma sintering processes. Mechanical properties of the sintered samples were measured by Vickers hardness tester.

The paper studies the impact of gaseous water on the stability of micron aluminum powders in time at room temperature using the method of gravimetric analysis. The stability was studied using methods of thermal analysis during heating up to 1200 °С in air. The composition of products was analyzed using X-ray diffraction analysis. It was found out that the stability of micron aluminum powders depends on partial pressure of water vapor: the increase of pressure results in decreased stability of powders. The work gives recommendations for storing micron aluminum powders.