• Applied Microscopy
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• 제38권3호
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• pp.213-219
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• 2008

신경계통의 가소성은 신경세포의 변화에 의해 이루어질 뿐 아니라 신경아교세포의 변화에 의해서도 이루어진다. 신경아교세포 중 별아교세포는 신경세포의 기능을 조절하므로 정상적인 뇌의 기능을 유지하는데 매우 중요하다. 뇌에서 편도복합체는 위험 혹은 유해한 일련의 감각정보를 받아들이는 구역으로 받아들인 일련의 이와 같은 정보를 통합하고 변환시켜 공포라는 감정을 만들어낸다. 이런 과정은 편도복합체 신경세포에서 분비되는 신경전달물질의 균형변화에 의해 이루어지며, 신경전달물질의 조절에 별아교세포가 관여하므로 본 연구에서는 출생 전 스트레스와 성장 후에 받은 스트레스가 편도복합체 별아교세포의 세포체에 어떤 영향을 미치는지 조사하였다. 이를 위해 흰쥐를 스트레스를 받지 않은 대조군 (CON), 성장 후 스트레스를 받은 군 (CONR), 출생 전 스트레스를 받은 군 (PNS), 출생 전 스트레스와 성장 후 스트레스를 모두 받은 군 (PNSR)으로 구분하였다. 별아교세포는 GFAP 항체를 이용한 면역조직화학 염색을 시행하여 확인하였으며, methylene blue/azure II로 대조 염색하였다. Neurolucida 프로그램을 이용하여 계측한 별아교세포의 세포체는 일부 편도복합체 신경핵에서 출생 전 스트레스를 받은 PNS군이 대조군에 비하여 면적이 증가하였으며, 이런 경향은 출생 전 스트레스를 받고 다시 성장 후 스트레스를 받은 PNSR군에서 더욱 증가하였다. 따라서 흰쥐의 편도복합체에 분포하는 별아교세포는 스트레스에 영향을 받아 비대해지는 경향을 보인 것으로 나타났으며, 출생 전 스트레스가 성장 후에도 영향을 미치는 것으로 사료된다.

• The Korean Journal of Physiology and Pharmacology
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• 제17권5호
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• pp.393-403
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• 2013

Baicalein (BA), a plant-derived active flavonoid present in the root of Scutellaria baicalensis, has been widely used for the treatment of stress-related neuropsychiatric disorders including depression. Previous studies have demonstrated that repeated restraint stress disrupts the activity of the hypothalamic-pituitary-adrenal (HPA) axis, resulting in depression. The behavioral and neurochemical basis of the BA effect on depression remain unclear. The present study used the forced swimming test (FST) and changes in brain neurotransmitter levels to confirm the impact of BA on repeated restraint stress-induced behavioral and neurochemical changes in rats. Male rats received 10, 20, or 40 mg/kg BA (i.p.) 30 min prior to daily exposure to repeated restraint stress (2 h/day) for 14 days. Activation of the HPA axis in response to repeated restraint stress was confirmed by measuring serum corticosterone levels and the expression of corticotrophin-releasing factor in the hypothalamus. Daily BA administration significantly decreased the duration of immobility in the FST, increased sucrose consumption, and restored the stress-related decreases in dopamine concentrations in the hippocampus to near normal levels. BA significantly inhibited the stress-induced decrease in neuronal tyrosine hydroxylase immunoreactivity in the ventral tegmental area and the expression of brain-derived neurotrophic factor (BDNF) mRNA in the hippocampus. Taken together, these findings indicate that administration of BA prior to the repeated restraint stress significantly improves helpless behaviors and depressive symptoms, possibly by preventing the decrease in dopamine and BDNF expression. Thus, BA may be a useful agent for the treatment or alleviation of the complex symptoms associated with depression.

• 대한한의학방제학회지
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• 제30권2호
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• pp.85-93
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• 2022

Objectives : This study investigated anti-inflammatory effects of Nardotidis seu Sulculii Concha water extract (NSCE) against restraint-induced stress. Methods : In vivo, NSCE was orally administered to male white mice at concentrations of 250 mg/kg and 500 mg/kg for 3 days, and then restraint-induced stress was induced for 6 hours. The level of liver damage was measured by serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH). The stress-related hormones such as cortisol and corticosterone were measured by ELISA assay. Also, western blot analysis was performed to detect expression of mitogen-activated protein kinase (MAPK) and cyclooxygenase-2 (COX-2) proteins. Pathological changes were observed by hematoxylin and eosin (H&E) staining of the liver tissue, and Immunohistochemical (IHC) staining was performed to examine liver inflammation through macrophage infiltration. Results : The AST, ALT, LDH and the stress related hormones such as cortisol and corticosterone were significantly decreased in the NSCE treated group compared with stress group. In histological analysis, H&E staining of liver tissues did not detect the hepatic injury or damage in all groups. As a result of IHC staining, it was confirmed that infiltration of macrophages was increased in the stress-induced group, but decreased in the group treated with NSCE. The COX-2 and MAPK proteins expression was significantly increased by restraint-induced stress, but these proteins were decreased in the NSCE treated group. Conclusions : These results suggest that NSCE has the anti-inflammatory activity in restraint-induced stress model, and it is believed that NSCE can be used for the prevention of liver inflammation.

• Journal of Welding and Joining
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• 제28권4호
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• pp.33-40
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• 2010

The purpose of this study is to establish a predictive equation of transverse residual stress at the thick FCA butt weldment of large container vessel. The variables used were restraint degree, yield strength of base material, thickness of weldment and welding heat input. Restraint degree at the thick weldment of container ship having the various welding sequence was calculated using FEA. From the result, the H-type specimen was designed to reproduce the level of restraint degree at the actual weldment of containership. Based on the results, the predictive equations of the mean value and the distribution of transverse residual stress at each location of the weldment were established using dimensional analysis and multiple-regression method. The predictive equations were verified by comparing with those measured by XRD in the actual weldment of the ship.

• Journal of Welding and Joining
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• 제33권6호
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• pp.6-12
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• 2015

Thermal fatigue life of the automobile exhaust manifold is directly affected by the restraint force according to the structure of exhaust system and bead shape of the welded joints. In the present study, the microstructural changes and precipitation behavior during thermal fatigue cycle of the 18wt% Cr ferritic stainless steel weld heat affected zone (HAZ) considering restraint stress were investigated. The simulation of weld HAZ and thermal fatigue test were carried out using a metal thermal cycle simulator under complete constraint force in the static jig. The change of the restraint stress on the weld HAZ was simulated by changing the shape of notch in the specimen considering the stress concentration factor. Thermal fatigue properties of the weld HAZ were deteriorated during cyclic heating and cooling in the temperature range of $200^{\circ}C$ to $900^{\circ}C$ due to the decrease of Nb content in solid solution and coarsening of MX type precipitates, laves phase, $M_6C$ with coarsening of grain and softening of the matrix. As the restraint stress on the specimen increased, the thermal fatigue life was decreased by dynamic precipitation and rapid coarsening of the precipitates.

• 동의신경정신과학회지
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• 제32권1호
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• pp.25-37
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• 2021

Objectives: Depression is a mood disorder showing low energy, loss of interest, anhedonia, and anxiety. It affects a patients' daily life. This disease is considered a social problem because the patient may commit suicide in extreme cases. JSB is composed of 12 Korean medicinal herbs. It has been prescribed to patients with depression. The objective of this study is to investigate anti-depressive effects of JSB on restraint stress-induced depression in a mouse model. Methods: Depression was induced by restraint stress. Mice were orally administered JSB at 10, 20, or 40 mg/kg for 14 days. Forced swimming test (FST) and open field test (OFT) were performed. Brain-derived neurotrophic factor (BDNF) mRNA level was measured by real time-PCR. Plasma levels of corticosterone and serotonin were measured by ELISA. Blood levels of AST and ALS were measured using a biochemical analyzer. Results: JSB treatment significantly reduced the immobility time in FST. BDNF mRNA level was increased by JSB treatment in the hippocampi of mice. Although the expression of TNF-α was also increased by JSB, such increase was not statistically significant. The increase of corticosterone level in plasma induced by restraint stress was significantly down-regulated by JSB. JSB reduced blood level of AST, but not ALT. Conclusions: JSB has a potential to manage depression, setting a foundation for clinical application of Korean medicine with safety.

• 한국공작기계학회논문집
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• 제16권6호
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• pp.86-93
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• 2007

The restraint force is required for the accurate measurement and analysis to protect weldment from residual stress. Also, this residual stress caused by cracks in weldments is often observed in the weldments of large size nozzles or radial tanks after welding. This paper is preformed to evaluate the welding restraint forces using load cell with STS304 thin plate which is used as the pressure vessel steel in the industry field. As a result, as the welding currents are higher and the welding speeds are more slowly, the magnitude of restraint force in process of the flat plate welding shows to be more large.

• Nuclear Engineering and Technology
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• 제39권1호
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• pp.75-84
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• 2007

This paper presents a closed-form model for evaluating the restraint effect of pressure induced bending on the opening of a circumferential through-wall crack, which is considered plastic deformation behavior. Three-dimensional finite element analyses with different crack lengths, restraint conditions, pipe geometries, magnitudes of internal pressure, and tensile properties were used to investigate the influence of each parameter on the pressure-induced bending restraint on the crack opening displacement. From these investigations, an analytical model based on elastic-perfectly plastic material was developed in terms of the crack length, symmetric restraint length, mean radius to thickness ratio, axial stress corresponding to the internal pressure, and normalized crack opening displacement evaluated from a linear-elastic crack opening condition. Finite element analyses results demonstrate that the proposed analytical model reliably estimated the restraint effect of pressure-induced bending on the plastic crack opening of a circumferential through-wall crack and properly reflected the dependence on each parameter within the range over which the analytical expression was derived.

• 한국안전학회지
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• 제18권1호
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• pp.1-7
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• 2003

The objective of this paper was to investigate the welding characteristics according to the restraint condition. the pass number, and the shield gas quantity with titanium commonly using in power stations, aircrafts, ships, and so forth. The residual stress distribution was measured under restraint and nonrestraint welding conditions. The tensile strength and elongation of the 4 pass welded specimen were shown higher about 10% and 30% than those of the 7 pass welded specimen at the same welding conditions respectably. Also, the more shield gas quantity and the shorter natural cooling time, the higher tensile strength and the lower elongation.

• The Korean Journal of Physiology and Pharmacology
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• 제20권5호
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• pp.467-476
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• 2016

In the present study, we examined the effect of pertussis toxin (PTX) administered centrally in a variety of stress-induced blood glucose level. Mice were exposed to stress after the pretreatment of PTX (0.05 or 0.1 mg) i.c.v. or i.t. once for 6 days. Blood glucose level was measured at 0, 30, 60 and 120 min after stress stimulation. The blood glucose level was increased in all stress groups. The blood glucose level reached at maximum level after 30 min of stress stimulation and returned to a normal level after 2 h of stress stimulation in restraint stress, physical, and emotional stress groups. The blood glucose level induced by cold-water swimming stress was gradually increased up to 1 h and returned to the normal level. The intracerebroventricular (i.c.v.) or intrathecal (i.t.) pretreatment with PTX, a $G_i$ inhibitor, alone produced a hypoglycemia and almost abolished the elevation of the blood level induced by stress stimulation. The central pretreatment with PTX caused a reduction of plasma insulin level, whereas plasma corticosterone level was further up-regulated in all stress models. Our results suggest that the hyperglycemia produced by physical stress, emotional stress, restraint stress, and the cold-water swimming stress appear to be mediated by activation of centrally located PTX-sensitive G proteins. The reduction of blood glucose level by PTX appears to due to the reduction of plasma insulin level. The reduction of blood glucose level by PTX was accompanied by the reduction of plasma insulin level. Plasma corticosterone level up-regulation by PTX in stress models may be due to a blood glucose homeostatic mechanism.