10000 0001 1364 9317grid.49606.3dHanyang University College of Medicine, Seoul, South Korea
20000 0004 1773 6524grid.412674.2Soonchunhyang University College of Medicine, Gumi, South Korea
30000 0004 0533 4667grid.267370.7Ulsan University College of Medicine, Ulsan, South Korea
40000 0001 1364 9317grid.49606.3dDepartment of Occupational and Environmental Medicine, Hanyang University College of Medicine, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763 South Korea
© The Author(s). 2018
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