ABSTRACT
The recent Coronavirus Disease 2019 pandemic has highlighted the importance of indoor ventilation. In particular, ventilation is crucial in residential spaces and workspaces, where people spent most of their day. Natural ventilation is a cost-effective method for improving indoor ventilation. It can provide safe and comfortable residential and working environments without additional energy consumption. In this study, the ventilation performance was experimentally studied by measuring the concentration of ultrafine particulate matter according to the opening conditions of the windows and door of an office model in a wind tunnel. Furthermore, the internal flow structure in the office model was quantitatively analyzed through particle image velocimetry to determine the factors that affected the ventilation performance. The mean velocity inside the model and the ventilation performance increased with the opening angle of the windows. In particular, the opening condition of the door strongly affected the ventilation performance. This study is expected to provide a guideline for effectively improving the ventilation performance in indoor spaces.
ABSTRACT
Oregonin, a diarylheptanoid derivative from Alnus hirsuta Turcz, Betulaceae, was evaluated for its antitumor activity. Oregonin, known to have an antitumor function, and is a novel immunomodulator, which may augment macrophage activity. MTT assays and NO production tests were performed in order to investigate the cytotoxicity of oregonin in tumor cells and to examine its influence on macrophage in detail. In this study, the tumoricidal activity was also evaluated by a MTT assay. The cytotoxicity measurements in the oregonin-treated group both in vitro and in vivo showed a significant difference from that of the control group. In vivo, oregonin significantly increased NO production in a dose-dependent manner, and in vitro, the thioglycolate-induced inflammatory macrophages increased NO production in a dose-dependent manner after incubation. These results suggest that oregonin reacts with both the inflammatory and non-inflammatory macrophages in a similar way.
