• Journal of Microbiology and Biotechnology
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• 제19권6호
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• pp.547-555
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• 2009

Nanoscopic changes in the cell surface morphology of the yeasts Saccharomyces cerevisiae (strain NCYC 1681) and Schizosaccharomyces pombe (strain DVPB 1354), due to their exposure to varying concentrations of hydrogen peroxide (oxidative stress), were investigated using an atomic force microscope (AFM). Increasing hydrogen peroxide concentration led to a decrease in cell viabilities and mean cell volumes, and an increase in the surface roughness of the yeasts. In addition, AFM studies revealed that oxidative stress caused cell compression in both S. cerevisiae and Schiz. pombe cells and an increase in the number of aged yeasts. These results confirmed the importance and usefulness of AFM in investigating the morphology of stressed microbial cells at the nanoscale. The results also provided novel information on the relative oxidative stress tolerance of S. cerevisiae and Schizo pombe.

• 아동학회지
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• 제28권4호
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• pp.305-317
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• 2007

This study investigated the effect of maternal interactive styles, parenting stress, home environment stimulation and social support on poverty in early childhood. Participants consisted of 145 mothers and their children living in Seoul and Kyounggi Province. Data included videotaped observations of parent-child play and standardized measures of social support, parenting stress, home environment, and child development. Results of the t-test indicated significant differences among father's age and education, mother's age and education, and income over the variable of poverty. Regression analyses indicated that home environment stimulation was the strongest predictor of variance in children's development. Results from the regression analyse were supportive of the hypothesis that home environment moderates the impact of poverty on children's development.

• 인간식물환경학회지
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• 제22권3호
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• pp.309-319
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• 2019

This study was conducted to investigate the effects of watching a virtual reality (VR) forest video on stress reduction in adults. Experiments were performed in an artificial climate chamber where temperature, humidity and illumination were controlled. To cause stress in subjects, the subjects were asked to multiply two digit numbers by one digit numbers for two minutes. The subjects then watched a VR forest video for five minutes. During the experiment, the heart rate variability (HRV) and heart rate (HR) of subjects were continuously measured for evaluating their physiological state. After measuring the baseline and watching a VR forest video, their psychological state was evaluated using the profile of mood state (POMS), semantic differential (SD) method, and positive affect and negative affect schedule (PANAS). The results of physiological evaluation after watching a VR forest video showed a decrease in the stress index and HR, an increase in the activity of the parasympathetic nervous system, and the standard deviation of normal to normal RR intervals (SDNN). The results of psychological assessment confirmed that watching a VR forest video induced "comfort", "natural", and "soothed" feelings in subjects. In addition, watching a VR forest video decreased "tension-anxiety (T-A)", "depression-dejection (D)", "anger-hostility (A-H)", "fatigue (F)", "total mood disturbance (TMD)", and increased "vigor (V)" compared to the base line, and decreased "negative affect" and increased "positive affect." These results indicate that watching a VR forest video decreases adults' stress index, stabilizes physiological state, and has a positive impact on psychological state. The findings of this study can serve as a basis for providing forest welfare services to people in the blind spots of forest welfare, and can lay a foundation for the adoption of VR, one of the technologies of the fourth industrial revolution in forestry.

• 대한간호학회지
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• 제5권1호
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• pp.93-111
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• 1975

As the hospitalized patients will be facing new stress situation due to change of his environment from home to hospital it will be very important to understand the psychological stress experienced by hospital patients not only for helping patients in the process of recovery from illness but also fulfil1ing the objective of comprehensive nursing care by understanding the needs of the patients. There is no doubt that it would be very helpful for treatment of patients as well as for improvement of nursing care if we know more about psychological needs of patients and give them adequate support to meet these needs. The study to find out the causes and degree of stress events experienced by hospitalized patients, with the objective of instituting improvement of nursing care program based on the needs of patients, was conducted during the month of September 1974 with 60 patients randomly selected from those admitted to medical and surgical wards at Yonsei Medical Center in that period The questionnaire form included 36 questions which are considered to be stress events for hospital patients, and was devide into five areas namely, such events related to 1) disease itself, 2) hospital environment, 3) nursing care and treatment, 4) communication and human relations, and 5) family and economic problems. The results of the study were as follows: 1. It was confirmed that hospitalization considered to be a stress producing factor and most patients perceived the admission to hospital as a stress factor. 2. According to the rating scale, it was found that degree of perceived stress shows a variation according to the source of stress producing event. 3. No significant differences in the mean values were observed statistically with the perceived stress levels according to demographic and other variables of patients related to hospitalization. 4. Among the questions related to disease itself, "Admission for surgery" was perceived most frequently as a stress event (97.14%) by patients. 5. With regard to the questions related to hospital environment, "death of the patient room-mate" was the most serious stress event perceived by patients (90%) and "living with hospital regulations"was considered to be less serious stress event (23.33%). 6. As for the questions related to nursing care and treatment, "limitation of freedom" was perceived as a stress factor most frequently (70.91%) by the patients and "worry for wrong treatment" turned out to be less frequent stress event (50.0%). 7. As for the questions related to communication and human relations, "difficulty to meet doctors when wanted"appeared to be the most frequent stress event by the respondents (75.86%) , followed by "no explanation about treatment or examination"(75.0%) and "no explanation about nursing care procedures"(71.66%). 8. With regard 111 tile questions related to family and economic problems, "inadequate finances for family living due to hospitalization"and "high cost of hospitalization" were the most frequent cause of stress mentioned by the patients. (80.0%). 9. As a result of application of the stepwise regression analysis, it was found that about 89% was explained by those events associated with disease itself, hospital environment and family and economic problems. By adding those events related to "nursing care and treatment" and "communication and human relation", 100% of stress associated with hospitalization was explained.

• Asian-Australasian Journal of Animal Sciences
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• 제33권5호
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• pp.722-731
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• 2020

Objective: Two experiments were conducted using 28 healthy multiparous sows to evaluate the oxidative stress status and reproductive performance of sows during gestation and lactation under different thermal environments. Methods: Fourteen multiparous sows were used in Exp. 1 under a high thermal environment, and the other 14 multiparous sows were used in Exp. 2 under a moderate thermal environment. In both experiments, reproductive performances of sows were recorded. Plasma samples were collected on d 35, 60, 90, and 109 of gestation, and d 1 and 18 of lactation for malondialdehyde, protein carbonyls, 8-hydroxy-deoxyguanosine, immunoglobulin g (IgG), and IgM analysis. Results: For sows in Exp. 1, plasma malondialdehyde concentration on d 109 of gestation tended to be greater (p<0.05) than it on d 18 of lactation. Plasma concentration of protein carbonyl on d 109 of gestation was the greatest (p<0.05) compared with all the other days. Plasma concentrations of 8-hydroxy-deoxyguanosine on d 109 of gestation was greater (p<0.05) than d 18 of lactation in Exp. 1. For sows in Exp. 2, there was no difference of malondialdehyde and protein carbonyl concentration during gestation and lactation. In both Exp. 1 and 2, litter size and litter weight were found to be negatively correlated with oxidative stress indicators. Conclusion: Sows under a high thermal environment had increased oxidative stress during late gestation indicating that increased oxidative damage to lipid, protein, and DNA could be one of the contributing factors for reduced reproductive performance of sows in this environment. This study indicates the importance of providing a moderate thermal environment to gestating and lactating sows to minimize the increase of oxidative stress during late gestation which can impair reproductive outcomes.

• Animal Bioscience
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• 제36권2호
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• pp.248-255
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• 2023

Objective: Stress factors such as high temperatures, overcrowding, and diurnal temperature range exert profound negative effects on weight gain and productivity of broiler chickens. The potential of gamma aminobutyric acid (GABA) as an excitatory neurotransmitter was evaluated under various stress conditions in this study. Methods: The experiment was conducted under four different environmental conditions: normal, high temperature, overcrowded, and in an overcrowded-diurnal temperature range. The experimental groups were divided into (-) control group without stress, (+) control group with stress, and G50 group (GABA 50 mg/kg) with stress. Weight gain, feed intake, and feed conversion ratio were measured, and stress reduction was evaluated through hematologic analysis. Results: The effects of GABA on broilers in four experimental treatments were evaluated. GABA treated responded to environmental stress and improved productivity in all the experimental treatments. The magnitude of stress observed was highest at high temperature, followed by the overcrowded environment, and was least for the overcrowded-diurnal temperature range. Conclusion: Various stress factors in livestock rearing environment can reduce productivity and increase disease incidence and mortality rate. To address these challenges, GABA, an inhibitory neurotransmitter, was shown to reduce stress caused due to various environmental conditions and improve productivity.

• 대한인간공학회지
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• 제34권6호
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• pp.549-561
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• 2015

Objective: The purpose of this study was to investigate the job stress factors of mobile communication network construction workers using survey based on 'Job stress factors evaluation tool for Koreans' that was developed by KOSHA in 2003. Background: Due to the rapid growth of penetration rate of smartphone, the necessity of LTE service changing from 3G network was brought up. The demand of LTE network construction in a short period of time leads to the aggravation of the job stress of mobile communication network construction workers. Method: Two hundred and fifty workers who were in the mobile communication network industry participated in this study, and among them 206 responses were analyzed for this study due to the unreliability and insincerity of responses. The eight job stress factors which are physical environment, job demand, job autonomy, relation conflict, job instability, organizational system, inadequate compensation, workplace culture were analyzed. Results: The job stress factors of mobile communication network construction workers were compared to those of other industry workers, and other work related characteristics were analyzed. The results showed that the stress level of a physical environment and job requirement were relatively higher than those of manufacturing industry workers, meaning that mobile communication network construction workers have rough working conditions and increased amount of work due to the demand of LTE network construction. The stress level of physical environment for outdoor job workers was relatively higher than that of indoor job workers. With the analytical result for level of job satisfaction, significant difference was observed (p <0.05) with every factor, and the job stress was found the highest with those not satisfied with every factor Conclusion: From the results of this study, the work loss due to the job stress could be prevented, and accurate stress factors could be removed at the workplace. Application: The results of this study may not represent the whole mobile network construction workers, the effort for job stress management is needed to improve the work efficiency and the workers' quality of life.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 1998년도 특별강연 및 추계학술발표 개요집
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• pp.288-291
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• 1998

Inconel 600 alloy is used as the material of nuclear steam generator tubing because of its mechanical properties, formability, and corrosion properties. According to reports, the life time of nuclear power plants decreases because of the pitting, intergranular attack, primary water stress corrosion cracking(PWSCC), and intergranular stress corrosion cracking(IGSCC), and denting in the steam generator. The SCC test is very important because of SCC appears in various environment such as solutions, materials, and stress. The C-Rig specimen was made of the steam generator welded sleeve repairing by the pulsed Nd:YAG laser. In the corrosion invironment, corrosion solutions are Primary Water, Caustic, and Sulfate solution and corrosion time is 1624-4877hr. The permitted stress is 30-60ksi.In this C-Ring SCC test is the relationship between corrosion depth, crack and corrosion environment is evaluated. SCC was happens in Sulfate and Corrosion solution but doesn't happen in Primary Water. The corrosion time and stress is very affected by the severely environment of Sulfate or Caustic solution. The microstructure observation indicates that SCC causes interganular failure in the grain boundary of vertical direction.

• 한국생활과학회지
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• 제18권6호
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• pp.1199-1208
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• 2009

The purpose of this study was to understand a mother's parenting behavior and home environment in relation to the stress of a male child. The subjects were 200 mothers of 4-6 years old children in early childhood programs located in Seoul and Gyeonggi province. Instruments used in this study were the Mother's Parenting Behavior Scale (Park Seong Yeon & Lee Suk, 1990), Home Scale (Jang Yeong Ae, 1981), and Children's Usual Stress Scale (Yeom Hyeon Gyeong, 1998). Data was analyzed by descriptive statistics, Pearson's correlation, and multiple regression analysis. Results indicated that (a) stress was shown to be higher if the mother's parenting behavior was authoritarian and over-protective, (b) children of lower economic background showed a higher stress level than middle and upper economic background subjects, and (c) the mother's educational background, authoritarian and over-protective parenting behavior and quality of the family background were meaningful variables for children's stress.

• 한국직업건강간호학회지
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• 제15권1호
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• pp.58-71
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• 2006

Purpose: This study was performed to identify workers' Job stress status and to analyse the influencing factors. Method: Data were collected from 456 workers with Korean Occupational Stress Questionnaire Short Form(KOSQ SF) and analysed using descriptive statistics, t-test, ANOVA. Results: Total job stress status of men was slightly lower than Korean workers' standard. In case of women, the score of total job stress was lower than Korean workers' standard. The most significant influencing factors to stressors were insufficient sleeping time and self cognitive bad health condition. Among seven domains of job stressors, job demand was affected by 8 characteristics. Conclusion: This study indicated that workers' job stress level were various by their characteristics except workplace size. The development of stress management programs by types of industry is required. On the base of the model program, planning of customized program for every company or employee is required. High job demand, insufficient job control, insufficient sleeping time, bad health condition are the key factors of workers' job stress in this study. The change of workers' health behavior with supportive environment is essential to stress management program. More researches for adding physical environment domain to KOSQ SF are expected.