Enhancement of NK Cell Cytotoxicity Induced by Long-Term Living in Negatively Charged-Particle Dominant Indoor Air-Conditions. oleh Yasumitsu Nishimura, Kazuaki Takahashi, Akinori Mase, Muneo Kotani, Kazuhisa Ami, Megumi Maeda, Takashi Shirahama, Suni Lee, Hidenori Matsuzaki, Naoko Kumagai-Takei, Kei Yoshitome, Takemi Otsuki