In order to improve the implementation of safety and health education at the site for industrial accident prevention activities, research was conducted to minimize inconvenience and increase utilization by redesigning and developing existing education methods. To date, occupational safety and health education has been conducted without considering the general work characteristics and functional facilities (mechanical, electrical, instrumentation, chemical) of workers (mechanical: turbine, valve, pump, hydraulic system, electrical: generator, breaker, motor, etc.). In particular, plant facilities were classified as mechanical and electrical facilities to improve the methodology for industrial safety and health education for plant maintenance workers. In addition, the “One Page Education Plan” was announced as a learning case because the spread of COVID-19 infectious diseases made it impossible to reduce or control the number of people in all groups and groups. The improvement of this training method will play a major role in improving the effectiveness of safety education in power plant workplaces.

The aim of this study was to enhance the proliferation efficiency of spermatogonial stem cells (SSCs). In order to improve the proliferation efficiency, we investigated new factors that promote the proliferation of SSCs using in vitro culture method with natural plant extracts. Germ cell populations containing SSCs were collected 6- to 8-days-old from C57BL/6-TG-EGFP (C57GFP) mice and SSCs were isolated from the collected cells via magnetic-activated cell sorting (MACS). Since then, SSCs were cultured for a week with culture medium containing natural plant extracts at concentration of 0.1, 1, and 10 μg/mL. After a week of culture, we looked for an increase, especially a dose-dependent increase, in the number of cells compared to that of the control group. A dose-dependent increase, in the number of cells was observed in the Petasides japonicus-treated groups. Furthermore, we carried out repeated experiment that is process consisting of selection and additional segmentation to explore new factors for activating SSCs at the molecular level. As a results, Petasides japonicus butanol fraction significantly increased the proliferation rate of SSCs in a dose-dependent manner among Petasides japonicus fraction samples. We identified normal expression level of PLZF in SSCs cultured with plant extracts using immunocytochemistry method. Furthermore, we also carried out qRT-PCR and identified normal expression level of Lhx1 and GFRα1. The finding of this study could contribute to improvement of proliferation and activation for SSCs, using culture method with natural plant extracts.