• Laboraroty Animal Research
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• v.34 no.4
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• pp.203-210
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• 2018

Stress severely disturbs physiological and mental homeostasis which includes adult neurogenesis in hippocampus. Neurogenesis in hippocampus is a key feature to adapt to environmental changes and highly regulated by multiple cellular signaling pathways. The primary cilium is a cellular organelle, which acts as a signaling center during development and neurogenesis in adult mice. However, it is not clear how the primary cilia are involved in the process of restraint (RST) stress response. Using a mouse model, we examined the role of primary cilia in repeated and acute RST stress response. Interestingly, RST stress increased the number of ciliated cells in the adult hippocampal dentate gyrus (DG). In our RST model, cell proliferation in the DG also increased in a time-dependent manner. Moreover, the analysis of ciliated cells in the hippocampal DG with cell type markers indicated that cells that were ciliated in response to acute RST stress are neurons. Taken together, these findings suggest that RST stress response is closely associated with an increase in the number of ciliated neurons and leads to an increase in cell proliferation.

• The Korean Journal of Rehabilitation Nursing
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• v.8 no.1
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• pp.20-30
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• 2005

Purpose: The purpose of this study was to investigate the stress level and health status of primary caregivers living with demented elderly. Method: The subject was 92 primary caregivers who had been taking care of demented elderly at home. The research tools were a stress questionnaire and health status questionnaire. The data were collected through direct interview with a questionnaire in the B city, from February to March 2004. The data were analyzed by t-test, ANOVA, Pearson's correlation coefficients and Scheffe test using SPSS/PC 11.0 program. Results: The primary caregivers living with demented elderly showed slightly high level of stress and moderate level of health status. Moreover, there was a significant correlation between the stress level and the mental and the physical health status. Conclusion: Based on the results, we recommend the development of an intervention program to decrease the stress level of primary caregivers living with demented elderly for improving their health status.

• Journal of Life Science
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• v.26 no.4
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• pp.490-495
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• 2016

Brefeldin A (BFA), a lactone antibiotic isolated from the fungus Eupenicillium brefeldianum, inhibits the transport of secreted and membrane proteins from the endoplasmic reticulum (ER) to the Golgi apparatus. BFA disrupts Golgi function, the accumulation of unfolded proteins in ER, and the induction of ER stress. Prolonged ER stress induces apoptosis at least in part through the transcription factor C/EBP (CCAAT/enhancer binding protein) homologous protein (CHOP),which is activated by the unfolded protein response (UPR). In this paper, we demonstrate that BFA-induced endoplasmic reticulum stress leads to different CHOP expression in primary astrocyte cells and C6 glioma cells. BFA induced lower CHOP expression levels in primary astrocyte cells than in C6 glioma cells; however, other ER stress inducers (thapsigargin and tunicamycin) resulted in similar expression patterns in these two cell types. Interestingly, the three different ER stress inducers (BFA, thapsigargin, and tunicamycin) induced similar levels of CHOP mRNA expression in primary astrocyte cells. The ubiquitin-proteasome inhibitor MG132 also markedly up-regulated the BFA-mediated CHOP protein expression in primary astrocyte cells. BFA also induced higher proteasome activity in primary astrocyte cells than in C6 glioma cells. Taken together, our results suggest that higher proteasomal activity might down-regulate BFA-induced CHOP expression in primary astrocyte cells.

• Journal of the Korean Society for Heat Treatment
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• v.18 no.3
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• pp.157-163
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• 2005

Effects of refinement of primary Si and residual stress on the mechanical properties of Aluminum B.390 alloy have been examined. Calcium was found to have an effect on the size of primary silicon particles. Primary silicon particle was refined as Ca content decreased. Refinement of primary Si particles led to an improvement in mechanical properties of the alloy; increase of elongation was prominent, above all. By the increase of compressive residual stress in the matrix alloy, tensile strength increased but elongation decreased.

• Child Health Nursing Research
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• v.18 no.4
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• pp.184-191
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• 2012

Purpose: The purpose of this study was to provide basic data for nursing interventions to assist primary caregivers of young children by determining the degree stress and fatigue that caregivers were under due to parenting young children. Methods: Participants were primary caregivers (181 mothers and 160 grandmothers) of young children. Results: 1) Mean score for degree of parenting stress was 2.61 (${\pm}.69$) and for fatigue, 1.97 (${\pm}.54$). 2) There was a significant difference in degree of parenting stress according to primary caregivers' age, employment status, income, whether the children were wanted babies, health status of the children and caregivers, personality of the children, and benefits from, and satisfaction with costs of childcare. Likewise, there was a significant difference in degree of fatigue according to relationship of primary caregivers to the children, primary caregivers' age, religion, income, whether the children were wanted babies, health status of the children and caregivers, personality of the children, and benefits from, and satisfaction with costs of childcare. 3) Stress and fatigue perceived by the primary caregivers were significantly correlated (r=.554 p<.001). Conclusion: To alleviate more effectively primary caregivers' parenting stress and fatigue, early nursing intervention and educational programs need to be developed.

• Nuclear Engineering and Technology
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• v.54 no.12
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• pp.4481-4490
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• 2022

In this study, a new rupture disk corrosion test (RDCT) method was developed for real-time detection of stress corrosion cracking (SCC) initiation of Alloy 600 in a primary water environment of pressurized water reactors. In the RDCT method, one side of a disk specimen was exposed to a simulated primary water at high temperature and pressure while the other side was maintained at ambient pressure, inducing a dome-shaped deformation and tensile stress on the specimen. When SCC occurs in the primary water environment, it leads to the specimen rupture or water leakage through the specimen, which can be detected in real-time using a pressure gauge. The tensile stress applied to the disk specimen was calculated using a finite element analysis. The tensile stress was calculated to increase as the specimen thickness decreased. The SCC initiation time of the specimen was evaluated by the RDCT method, from which result it was found that the crack initiation time decreased with the decrease of specimen thickness owing to the increase of applied stress. After the SCC initiation test, many cracks were observed on the specimen surface in an intergranular fracture mode, which is a typical characteristic of SCC in the primary water environment.

• Nuclear Engineering and Technology
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• v.48 no.4
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• pp.1036-1046
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• 2016

We propose a primary water stress corrosion cracking (PWSCC) initiation model of Alloy 600 that considers the stress triaxiality factor to apply to finite element analysis. We investigated the correlation between stress triaxiality effects and PWSCC growth behavior in cold-worked Alloy 600 stream generator tubes, and identified an additional stress triaxiality factor that can be added to Garud's PWSCC initiation model. By applying the proposed PWSCC initiation model considering the stress triaxiality factor, PWSCC growth simulations based on the macroscopic phenomenological damage mechanics approach were carried out on the PWSCC growth tests of various cold-worked Alloy 600 steam generator tubes and compact tension specimens. As a result, PWSCC growth behavior results from the finite element prediction are in good agreement with the experimental results.

• Nuclear Engineering and Technology
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• v.44 no.3
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• pp.343-354
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• 2012

Primary water stress corrosion cracking (PWSCC) is a major safety concern in the nuclear power industry worldwide. PWSCC is known to initiate only in the condition in which sufficiently high tensile stress is applied to alloy 600 tube material or alloy 82/182 weld material in pressurized water reactor operating environments. However, it is still uncertain how much tensile stress is re-quired to generate PWSCC or what causes such high tensile stress. This study was performed to pre-dict the magnitude of weld residual stress and operating stress and compare it with previous experi-mental results for PWSCC initiation. For the study, a pressurizer safety nozzle was selected because it is reported to be vulnerable to PWSCC in overseas plants. The assessment was conducted by nu-merical analysis. Before performing stress analysis for plant conditions, a preliminary mock-up ana-lysis was done. The result of the preliminary analysis was validated by residual stress measurement in the mock-up. After verification of the analysis methodology, an analysis under plant conditions was conducted. The analysis results show that the stress level is not high enough to initiate PWSCC. If a plant is properly welded and operated, PWSCC is not likely to occur in the pressurizer safety nozzle.

• Korean Journal of Adult Nursing
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• v.21 no.2
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• pp.187-198
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• 2009

Purpose: This study was to compare and examine the factors influencing burden of primary family caregivers according to the severity of illness of elderly patients admitted in an intensive care unit. Methods: Subjects were the families of elderly patients in intensive care units of K, S and Y hospitals in Seoul. Data were collected from March to October 2007. Subjects were 108 persons over age 65. Data were analyzed by SAS statistics. Results: First, groups 5 and 3 showed higher burden than that of group 4. Second, high correlation was found between stress and burden, stress and anxiety, and burden and anxiety. Third, factors influencing family burden were found to be stress for group 5, stress, anxiety, and monthly income for group 4, and stress and patient age for group 3. Conclusion: Specific nursing interventions to decrease the stress of primary family caregivers of serious ill elderly patients in an intensive care unit are needed. Additionally, more effective and systematic activation of a long-term medical insurance system for seriously ill seniors is considered necessary to mediate the burden of primary family caregivers.

• Journal of the Society of Naval Architects of Korea
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• v.44 no.6
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• pp.605-611
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• 2007

A ship is composed of many grillage structures especially the deck which is consists of primary girders, transverse and longitudinal members. Several holes are arranged on these primary members for pipes, vents, etc. which cause stress concentration due to the discontinuity of the member. It is not easy to get the stress values around all these holes because of the huge amount of time necessary for computations. In this paper, a simple method to compute for the stress around the holes is suggested. This method is composed of two steps which are grillage analysis for primary members and detailed stress analysis using the results of the grillage analysis. This method is made for the design of the primary members with openings supporting the deck structure.