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Seunghyeon Cho,Won-Ju Park,Wonyang Kang,Hyeong-Min Lim,Ji-Sung Ahn,Dae-Young Lim,Jai-Dong Moon 대한직업환경의학회 2019 대한직업환경의학회지 Vol.31 No.-
Background: Dehydroepiandrosterone sulfate (DHEAS) is an endogenous steroid hormone produced by the adrenal gland. DHEAS has been suggested to play a protective role against psychosocial stress. The aim of this study was to investigate the association between job-related stress and blood concentrations of DHEAS according to occupational stress factors among female nurses. Methods: A cross-sectional study was conducted among 118 premenopausal nurses from 4 departments (operating room, emergency room [ER], intensive care unit, and ward) of a university hospital. Participants were all rotating night shift workers who have worked for over a year and mean age of 33.5 ± 4.8 years. Data from structured questionnaires including the Korean Occupational Stress Score, Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), and Pittsburgh Sleep Quality Index (PSQI) were used. Results: In the high job-related stressor group, scores of BDI, BAI, and PSQI were significantly higher than low-stressor group. ER nurses had relatively more work-burden related stressors, but they had significantly lower levels of anxiety and depression than other groups. And, ER nurses showed higher levels of DHEAS than the other department nurses. The differences were significant (p = 0.003). Additionally, there was a statistically significant difference even after adjusting for factors that could affect level of DHEAS, such as age, body mass index, drinking, and physical activity (p = 0.039). Conclusions: This result suggests the possibility that DHEAS may play a role as a marker of proper stress management. The capacity to secrete DHEAS is not simply due to workload or job stressor but could be determined depending on how individuals and groups deal with and resolve stress. Proper resolution of stress may affect positive hormone secretion.
High Performance of NanoCellulose/Nanochitin Coating Polypropylene Film for Food Packaging Materials
Seunghyeon LEE,Dongsoo HWANG 한국생물공학회 2021 한국생물공학회 학술대회 Vol.2021 No.10
In food packaging industry, it is important to possess barrier properties which prevent oxygen gas and water vapor. In general, aluminum coated polypropylene films are used because aluminum has a good gas barrier ability. However, this film is difficult to reuse and generate harmful particle when finally incinerated. In this study, we made a renewable food packaging film using the two most abundant biorenewable resources, cellulose and chitin. The structure of this film is simply made by stacking TEMPO cellulose nanofibers and Chitin nanowhiskers on polypropylene, and coating layers can sufficiently prevent oxygen gas and water vapor permeation. Compared with pristine pp, oxygen gas and water vapor permeability were significantly reduced from 1118 to 13.10㏄ m-2day-1 and from 2.43 to 2.13g m-2day-1, respectively. Furthermore, it has high transparency and antibacterial effect, so it can be expected as a new renewable food packaging material.