• Safety and Health at Work
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• v.2 no.2
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• pp.169-175
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• 2011

Objectives: The questionnaire of occupational stress index (OSI) has been popular in the workplace, and it has been tailored for bus drivers in Taiwan. Nevertheless, its outcomes for participants are based on self-evaluations, thus validation by their physiological stress biomarker is warranted and this is the main goal of this study. Methods: A cross-sectional study of sixty-three city bus drivers and fifty-four supporting staffs for comparison was conducted. Questionnaire surveys, 24-hour urine cortisol testing, and blood draws for dehydroepiandrosterone-sulfate (DHEA-S) testing were performed. The measured concentrations of these biological measures were logarithmically transformed before the statistical analysis where various scores of stressor factors, moderators, and stress effects of each OSI domain were analyzed by applying multiple linear regression models. Results: For drivers, the elevated 24-hour urine cortisol level was associated with a worker's relationship with their supervisor and any life change events in the most recent 3 months. The DHEA-S level was higher in drivers of younger age as well as drivers with more concerns relating to their salary and bonuses. Non-drivers showed no association between any stressor or satisfaction and urine cortisol and blood DHEA-S levels. Conclusion: Measurements of biomarkers may offer additional stress evaluations with OSI questionnaires for bus drivers. Increased DHEA-S and cortisol levels may result from stressors like income security. Prevention efforts towards occupational stress and life events and health promotional efforts for aged driver were important anti-stress remedies.

• Research in Community and Public Health Nursing
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• v.32 no.3
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• pp.404-414
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• 2021

Purpose: Health behaviors for metabolic syndrome (MetS) prevention should be emphasized from early adulthood. There is little information on psychosocial factors associated with health behaviors for MetS prevention. The aim of this study was to determine whether there would be a mediating effect of perceived stress on the association between social support and health behaviors for MetS prevention among university students. Methods: This cross-sectional and correlation study was conducted with 502 university students in South Korea. Social support, perceived stress, and lifestyle evaluation for metabolic syndrome scales were used. Online questionnaire survey was conducted between November and December 2019. The mediating effect of social support on health behaviors for MetS prevention was analyzed using PROCESS macro program with bootstrapping method to test our hypotheses. Results: Social support directly influenced perceived stress (β=-.35, p<.001) and health behaviors for MetS prevention (β=.14, p=.002). Health behaviors for MetS prevention was indirectly influenced by perceived stress (β=-.25, p<.001). The size of indirect effect of social support on health behaviors for MetS prevention was 0.06. Conclusions: The association of social support and health behaviors for MetS prevention was partially mediated by perceived stress among university students. Therefore, a university-based nursing intervention should comprise social support strategies with stress management to promote health behaviors for MetS prevention.

• Healthcare Informatics Research
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• v.24 no.4
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• pp.381-386
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• 2018

Objectives: This study aimed to describe the process of utilizing a mobile application for ecological momentary assessment (EMA) to collect data on stress and mood in daily life setting. Methods: A mobile application for the Android operating system was developed and installed with a set of questions regarding momentary mood and stress into a smartphone of a participant. The application sets alarms at semi-random intervals in 60-minute blocks, four times a day for 7 days. After obtaining all momentary affect and stress, the questions to assess the usability of the mobile EMA application were also administered. Results: The data were collected from 97 police officers working in Gyeonggi Province of South Korea. The mean completion rate was 60.0% ranging from 3.5% to 100%. The means of positive and negative affect were 18.34 of 28 and 19.09 of 63. The mean stress was 17.92 of 40. Participants responded that the mobile application correctly measured their affect ($4.34{\pm}0.83$) and stress ($4.48{\pm}0.62$) of 5-point Likert scale. Conclusions: Our study investigated the process of utilizing a mobile application to assess momentary affect and stress at repeated times. We found challenges regarding adherence to the research protocol, such as completion and delay of answering after alarm notification. Despite this inherent issue of adherence to the research protocol, the EMA still has advantages of reducing recall bias and assessing the actual moment of interest at multiple time points that improves ecological validity.

• Journal of Korean Biological Nursing Science
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• v.23 no.1
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• pp.22-30
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• 2021

Purpose: This descriptive study aimed to investigate heart rate variability (HRV) according to sex and to elucidate the influence of negative emotion such as levels of stress, anxiety and depression on HRV among Korean college students based on a neurovisceral integration model. Methods: A descriptive study design was used. Eighty-six healthy college students participated in the study. Resting HRV and standing HRV on orthostatic stimulation were measured for 5 minutes during 4-6 p.m. in the afternoon. Levels of stress, anxiety and depression were assessed using the Global assessment of recent stress, State-Trait Anxiety Inventory and Beck Depression Index, respectively. Results: Out of the 86 students, 47 (54.7%) were men and 39 (45.3%) were women. Root mean square of the differences between adjacent RR intervals (RMSSD) and normalized high frequency (nHF) on standing HRV were significantly lower in men than in women (p= .005, p= .019, respectively). Male gender (β= 0.30, p= .013), higher level of stress (β= -0.36, p= .009) and lower level of depression (β = 0.30, p= .044) exerted a significant influence on decreased nHF in the multiple regression analysis. Conclusion: We suggest that men are more vulnerable to having reduced vagal activity on HRV than women. Since male gender, higher level of stress and lower level of depression level influenced decreased vagal activity, strategies are needed to improve stress and depression rather than anxiety especially for men, which contribute to promoting HRV to prevent cardiac health diseases.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.2
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• pp.206-214
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• 2023

Objectives: To determine the effect of the various type and number of shift work on sociopsychological stress in the university hospital nurses in Seoul, South Korea. Methods: Data was collected through a self-administered questionnaire that included general characteristics, the type and number of shift work in the past 4 weeks and the an sociopsychological stress based on PWI-SF. Logistic regression analysis was conducted to analyze the effect of shift work by types on sociopsychological stress of university hospital nurses using SAS 9.4 and it adjusted general characteristics by the additional models. Results: When the number of night shift work 3 or 4 compared to 0, sociopsychological stress was significantly high(OR=2.16, 95% CI=1.29-3.65). When 5 or more, it was higher(OR=2.39, 95% CI=1.55-3.72). Two continuous night shift work compared to 0 increased sociopsychological stress(OR=2.37, 95% CI=1.49-3.81) and 3 or more even more(OR=2.70, 95% CI=1.72-4.27). If the shift work type changes 14 or 15 times compare to below 11, sociopsychological stress is increased and even higher when 15 or more times but it's not significant after adjusting for covariates. Conclusions: It suggests that workplace with nurse expose to shift work should be on lookout for more than three night shift work, more than two continuous night shift work and more than 14 shift work change which can lead to burnout, absenteeism, depression and decreased productivity.

• Structural Engineering and Mechanics
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• v.66 no.5
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• pp.649-663
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• 2018

The scaled boundary finite element method is extended to evaluate the dynamic stress intensity factors and T-stress with a numerical procedure based on the improved continued-fraction. The improved continued-fraction approach for the dynamic stiffness matrix is introduced to represent the inertial effect at high frequencies, which leads to numerically better conditioned matrices. After separating the singular stress term from other high order terms, the internal displacements can be obtained by numerical integration and no mesh refinement is needed around the crack tip. The condition numbers of coefficient matrix of the improved method are much smaller than that of the original method, which shows that the improved algorithm can obtain well-conditioned coefficient matrices, and the efficiency of the solution process and its stability can be significantly improved. Several numerical examples are presented to demonstrate the increased robustness and efficiency of the proposed method in both homogeneous and bimaterial crack problems.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.80-88
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• 2020

This study aimed to determine the effects of self-esteem, appearance satisfaction, and satisfaction in their major on the employment stress of nursing college students. The subjects were 194 students from four colleges of nursing in P-province in Korea. Data were collected from self-administered questionnaires, t-test, ANOVA, Pearson's and Spearman's correlation coefficients. Multiple regression with dummy variables was used for statistical analysis of the data. The results revealed the following scores: self-esteem 3.40±0.53, appearance satisfaction 2.96±0.56, satisfaction with the major 3.80±0.61, and employment stress 2.23±0.75. Significant differences in employment stress according to general characteristics of subjects were observed in gender (t=7.40, p=.007), entering nursing college motivation (F=3.24, p=.023), and college life satisfaction (F=16.722, p<.001). Employment stress showed a negative correlation with self-esteem (r=-.433, p<.001), appearance satisfaction (r=-.307, p<.001), and satisfaction in major (r=-.534, p<.001). The satisfaction with the major (β=-.371, p<.001), self-esteem (β=-.166, p=.026), appearance satisfaction (β=-.132, p=.045), entering nursing college motivation (β=.163, p=.006), and gender (β=.131, p=.033) confirmed as a factors affecting the employment stress and accounted for 35.6% of the variance. Based on the results, it is necessary to develop employment-competency reinforcement programs to increase the level of satisfaction in the major, appearance satisfaction, and self-esteem to reduce the employment stress of nursing college students.

• Journal of Korean Academy of Nursing
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• v.42 no.4
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• pp.496-507
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• 2012

Purpose: This study was based on social-role theory, and purposes were to investigate (1) how depression and health determinants vary with married and employed women, and (2) what factors contribute to depression according to family cycle. Methods: A stratified convenience sample of 765 married and employed women was recruited during May to August 2010. Study variables of depression, socio-demographic threatening factors, psycho-stimulating factors, and social-role related factors were measured via a structured questionnaire. Results: Prevalence rate for depression was 18.6%, with highest rate (25.4%) from elementary laborers. Greater levels of depression were related to women's occupation, higher life stress, and poorer health; lower social support and vulnerable personality; higher levels of social-role related stress. From multivariate analysis, women with preadolescents were the most vulnerable to depression affected by occupation, life stress, personality, and parenting stress. These factors (except for occupational class) combined with economic status, social support, and housework unfairness were significant for depression in women with adolescents. Conclusion: Depression among married and employed women differs by psycho-stimulating and social role relevant factors in addition to occupational class and family life cycle. Female elementary laborers and women with children need to have the highest prioritization for community mental health programs.

• Journal of Plant Biotechnology
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• v.41 no.1
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• pp.26-32
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• 2014

Recent genome annotation revealed that Populus trichocarpa contains 81 glutathione S-transferase (GST) genes. GST genes play important and varying roles in plants, including conferring tolerance to various abiotic stresses. Little information is available on the relationship - if any - between drought/salt stresses and GSTs in woody plants. In this study, we screened the PatgGST genes in hybrid poplar (Populus alba ${\times}$ Populus tremula var. glandulosa) that were predicted to confer drought tolerance based on our expression analysis of all members of the poplar GST superfamily following exposure to salt (NaCl) and drought (PEG) stresses, respectively. Exposure to the salt stress resulted in the induction of eight PatgGST genes and down-regulation of one PatgGST gene, and the level of induction/repression was different in leaf and stem tissues. In contrast, 16 PatgGST genes were induced following exposure to the drought (PEG) stress, and two were down-regulated. Taken together, we identified seven PatgGSTs (PatgGSTU15, PatgGSTU18, PatgGSTU22, PatgGSTU27, PatgGSTU46, PatgGSTU51 and PatgGSTU52) as putative drought tolerance genes based on their induction by both salt and drought stresses.

• Advances in concrete construction
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• v.11 no.3
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• pp.255-260
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• 2021

Vibration of protein microtubules is investigated based upon Orthotropic Elastic Shell Model, considering the effect of thermal stresses. The complete analytical formulas of thermal vibration for microtubules are obtained. It is observed that the effects of thermal stresses on the vibrational frequency mode are more significant when the longitudinal and circumferential wave vectors are large enough. But when the length of wave vector reduces to 5 nm, these effects have no significant effects. The present results well agree with the lattice vibrations of microtubules. Moreover, the results show that the effects of thermal stresses due to small change in temperature are not so significant but with the increase in temperature its effects are obvious.