Search

Epithelial ovarian carcinoma (EOC) is the leading cause of cancer-related death in women in Western countries. Once patients experience recurrence, complete cure is almost impossible. We elucidated the effect of nonequilibrium atmospheric pressure plasma on the growth of EOC, particularly in plasma-activated medium (PAM). Furthermore, we examined the role of reactive oxygen species (ROS) or their scavengers in chronic antineoplastic-resistant EOC cells. As a result, we showed PAM induced the antitumor effect of EOC cells in vitro and in vivo, even in chemoresistant cells. To apply the plasma treatment for advanced or recurrent EOC, we suggest adopting indirect plasma therapy instead of direct plasma considering intraperitoneal administration in the future. However, there are several problems under investigation, including intracellular mechanism of antitumor effect by PAM and adverse event in vivo.

Two independent ovarian cancer cell lines and fibroblast controls were treated with nonequilibrium atmospheric pressure plasma (NEAPP). Most ovarian cancer cells were detached from the culture dish by continuous plasma treatment to a single spot on the dish. Next, the plasma source was applied over the whole dish using a robot arm. In vitro cell proliferation assays showed that plasma treatments significantly decreased proliferation rates of ovarian cancer cells compared to fibroblast cells. FACS and Western blot analysis showed that plasma treatment of ovarian cancer cells induced apoptosis. NEAPP could be a promising tool for therapy for ovarian cancers.

Advanced diagnostics of high-density inductively coupled plasmas (ICPs) are presented supporting the following three proposals of innovative etching modes: First, pulsed plasma etching mode can suppress charge-up on high-aspect-ratio micro-patterns. In order to understand the mechanism, time-resolved measurements of electrons, chlorine atoms and negative ions in a pulsed chlorine ICP are performed. As a result of electron cooling and negative ion yield in afterglow, electrons are found to be accelerated toward a rf-biased electrode, thus neutralizing positive surface charges on that. Second, downstream etching mode using C4F8 gas enables high etch selectivity of SiO2 to Si. The reason for this is qualitatively discussed using comprehensive measurements of spatial distributions of CF3, CF2, CF and F densities in CF4 and C4F8 plasmas. Third, hot wall etching mode also enables high selectibity etching in fluorocarbon plasmas. Radical diagnostics reveal that wall heating dramatically modifies the radical composition of both CF4 and C4F8 plasmas, and it improves the etch selectivity and reproducibility.

Multilayer films consists of noble metal (Pd, Pt, Cu, Au, PdSi) and transition metal(Co, Ni, PdCo, PtCo, CoZr) layers were prepared by rf sputtering method on glass and/or MgO single crystal substrates. The perpendicular magnetic anisotropy was examined in relation to the magnetostriction, lattice misfits, crystallinity and crystal orientations. The results suggest that the perpendicular magnetic anisotropy in noble metal/PdCo alloy multilayers originates from the magnetoelastic energy of the PdCo layers under a stress due to the lattice misfits. In both Pd/Co and Pd/Ni multilayers, the anisotropy was found to depend on the crystal orientation, and the dependence is discussed from the view point of the magnetoelastic surface anisotropy.