• Journal of Society of Preventive Korean Medicine
• /
• v.5 no.2
• /
• pp.114-121
• /
• 2001

To elucidate the preventive effect of oriental medicine Gami-Ondamtang(GO) on stress, we investigated the physiological change of rats which were applied immobilization stress. For immobilization stress, rats were placed in restrainer for 12 hours a day for 3 days. During application of stress, body weight of rats was measured. After sacrifice, 8 organs were taken for measurement of organ weight. Brain was sectioned into 4 parts that are Frontal Cortex, Corpus Striatum, Hypothalamus and Hippocampus. Each part was homogenated and its catecholamine and serotonin contents were measured with HPLC. In our study, stress mainly induced increase of concentration of neurotransmitters in brain without other significant physical change of rats. GO inhibited stress induced changes of neurotransmitter content in brain.

• Environmental Analysis Health and Toxicology
• /
• v.13 no.3_4
• /
• pp.143-149
• /
• 1998

To elucidate the preventive effect of Danchisoyosan (DS) on stress, we investigated the physiological change of rats which were applied immobilization stress. For immobilization stress, rats were placed in restrainer for 12 hours a day for 3 days. During application of stress, body weight of rats was measured. After sacrifice, 8 organs were taken for measurement of organ weight. Brain was sectioned into 4 parts that are Frontal Cortex, Corpus Striatum, Hypothalamus and Hippocampus. Each part was homogenated and its catecholamine and serotonin contents were measured with HPLC. In our study, stress mainly induced increase of concentration of neurotransmitters in brain without other significant physical change of rats. DS inhibited stress induced changes of neurotransmitter content in brain.

• Journal of the Korean Magnetics Society
• /
• v.5 no.5
• /
• pp.470-473
• /
• 1995

We have constructed an apparatus for in sity measurement of stress of the film prepared by sputtering using an optical noncontact displacement detector. A Change of the gap distance between the detector and the substrate, caused by stress of a deposited film, was detected by a corresponding change of the reflectivity. The sensitivity of the displacement detector was $5.9\;{\mu}V/{\AA}$ and thus, it was turned out to be good enough to detect stress caused by deposition of a monoatomic layer. The apparatus was applied to in situ stress measurements of Co/X(X=Pd or Pt) multilayer thin films prepared on the glass substrates by dc magnetron sputtering. At the very beginning of the deposition, both Co and X sublayers have subjected to their own intrinsic stresses. However, when the film was thicker than about $100{\AA}$, constant tensile stress in the Co sublayer and compressive stress in the X sublayer were observed, which is believed to be related to a lattice mismatch between the matching planes of Co and X.

• Proceedings of the KSME Conference
• /
• 2001.06a
• /
• pp.237-242
• /
• 2001

Residual stress is a dominant obstacle to efficient production and safe usage of products by reducing the mechanical strength and failure properties. Especially, it causes interfacial failure and substrate deflection in the case of thin film. So, the exact evaluation and optimum control of thin film residual stress is indispensable. However, hole drilling or X-ray diffraction techniques have some limits in application to thin film. And, curvature technique for thin film materials cannot give the information about local stress variation. Therefore, we applied the nanoindentation technique in evaluating the thin film residual stress. In this study, we modeled the change of indentation loading curve for residually stressed and stress-free thin films during stress relaxation. The value of residual stress was directly related to the indentation depth change by relaxation. The residual stress from nanoindentation analysis was consistent with the result from curvature technique.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.15 no.2
• /
• pp.436-444
• /
• 1991

A computational method has been developed to analyze the bone-remodeling induced by external fixator. The method was based on the Finite Element Method (FEM) in combination with numerical formulation of adaptive bone-remodeling theories. As a feed-back control variable, compressive strain and effective stress were used to determine the surface remodeling and internal (density) remodeling respectively. Surface remodeling and internal remodeling were combined at each time step to predict the rel situation. A noticeable shape and density change were detected at the region between two pins and density change was decreased with time increment. At final time step, the shape and density distribution were converged closely to its original intact bone model. Similar change was detected in stress distribution. The altered stress distribution due to the pin and external fixator converged to the intact stress distribution with time.

• Human Ecology Research
• /
• v.58 no.3
• /
• pp.447-461
• /
• 2020

This study explores how the COVID-19 pandemic has changed family life and relationships as well as how these changes affect perceived stress among married men and women. This study investigated changes in family time use, household work, child care, leisure activities, income and expenditures along with relationships between spouses and children using a sample of 627 married persons surveyed online from May 19 to 25, 2020. The results showed that the amount of time spent on household work, child care, and family leisure have increased and that the perceived burden of household work and child care has also increased. Gender differences were found in time use, household work, and child care. Leisure activities have changed toward more time watching TV or online media and playing online games and less time on outdoor activities, shopping, and meeting friends. About 38% of respondents reported a reduction in household income and 22% reported an increase in household debt. The majority experienced no change in the quality of relationships with spouses and children, approximately 20% of the sample reported a positive change in relationships with spouses and children. The findings of multivariate regression indicated that change in work time, negative change in household economy, negative change in household work and negative change in relationships with spouses were associated with marital stress. However, this study found that negative changes in child care and in relationships with children did not affect stress among married parents with children in elementary or secondary school.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.21 no.9
• /
• pp.1392-1399
• /
• 1997

In order to determine the Mode I stress intensity factor ($K_1$) experimentally by means of the alternating current potential drop(ACPD) technique, the change in potential drop due to load for a ferromagnetic material containing a two-dimensional surface crack was examined. The cause of the change in potential drop and the effect of the magnetic flux on the change in potential drop were clarified by using the measuring systems with and without removing the magnetic flux from the circumference of the specimen. To remove the magnetic flux, a new measuring system was made by utilizing the characteristic of coaxial transmission line. The change in potential drop in the case without magnetic flux in the air was caused by the change in electromagnetic properties near the crack tip due to magnetization. The relationship between the change in potential drop and the change in $K_I$ was linealized by demagnetization and was found to be independent of the crack length.

• The Journal of Advanced Prosthodontics
• /
• v.12 no.4
• /
• pp.204-209
• /
• 2020

PURPOSE. Prevention of xerostomia and stress is important to prolong healthy life expectancy and improve the quality of life. We aimed to investigate the effects of tongue rotation exercise for increasing salivary secretions and stabilizing salivary stress hormone levels. MATERIALS AND METHODS. Twenty four participants without subjective oral dryness were enrolled. The exercises comprised tongue rotation exercise and empty chewing. The salivary stress hormone level was measured using a Salivary Amylase Monitor. Unstimulated whole saliva volume and salivary amylase activity were measured before tongue rotation exercise or empty chewing and subsequently 5, 10, and 15 minutes after these exercises. Differences in the rates of change of unstimulated whole saliva volume and salivary amylase activity were analyzed by repeated measure analysis of variance. RESULTS. Statistically significant differences among the rates of change were not observed after empty chewing for unstimulated whole saliva volume and salivary amylase activity at the four measurement times. However, the rate of change of unstimulated whole saliva volume and salivary amylase activity were statistically significantly different among the four time points: before the tongue rotation exercise and 5, 10, and 15 minutes post-exercise (P<.05 and P<.01, respectively). CONCLUSION. Tongue rotation is effective in increasing saliva secretion, reducing stress, improving oral function, and extending healthy life expectancy.

• Journal of Veterinary Clinics
• /
• v.15 no.1
• /
• pp.1-7
• /
• 1998

The present study was performed to evaluate circadian rhythm of blood nortisol concentration and change of blood cortisol concentration by various stress type in domestic cats. The ELISA kit for cortisol measurement was evaluated on the effective assay range, day to day variation, within-run variation and accuracy. The results were 1-1,000 ng/ ml, 0.7-5.9%, 0.9-4.5% and 98%, respectively. The circadian rhythm of serum cortisol concentration is presented in cats. Change of serum cortisol concentration was also examined with several stressors, stimulation with hamster as a prey, beep electronic sounds, vehicle transportation and unfamiliar environment. Unfamiliar environment showed most remarkable change in serum cortisol level.

• Korean Journal of Psychosomatic Medicine
• /
• v.9 no.1
• /
• pp.66-80
• /
• 2001

Most people experience stress during his or her life. The types of psychosocial stressors are variable. Also, the stress appraisal, coping, and responses in stress process are variable. These varieties reflect individual differences due to ongoing social situation, personal dispositions such as personal resources and vulnerability factors, etc. The stress process results in psychosocial growth or no substantial change in functioning or health, or adverse change in functioning(illness) or health to person. Therefore, the preventive management and treatment of stress need to be tailored to individual characteristics. All physicians managing the stress-related patients have to understand the multidimensional aspects of stress. To understand stress better in psychosocial aspect, I comprehensively reviewed the literature on stress.