• 한국동물학회지
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• 제7권1호
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• pp.23-28
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• 1964

120 mice of both sexes weighing from 18 to 22 g. were used. These mice were divided nito 12 groups : control (non-restraint and restraint) , acclinmation (non-restraint and restraint , acclimation for 5 and 10 days) , adrenalectomized (non-restraint and restraint0 and acclimation-adrenalectomized (non-restraint and restraint, acclimation for 5 and 10 days) groups. The rectal temperature of each group were measured at 10, 30 and 50 min under environment of $0^{\circ}C$.Measurements were done with a microphrometer of B.T.-32 thermocorpules. The results obtained may be summarized as follows : 1) The rectal temperature in normal mice without restraint was higher than that of normal mice with restraint under environment of $0^{\circ}C$. 2) The rectal temperature in normal mice was higher than that of adrenalectomized mice at 20$^{\circ}$ C. But the rectal temperature in adrenalectomized mice without restraint was higher than that of adrenalectomized mice with restraint under cold-stress. This difference was in the order of 1.65$^{\circ}$ under environment of 20$^{\circ}$ and 10 $^{\circ}$ at 50 min under environment of 0$^{\circ}$. 3) The rectal temperature of normal mice with restraint was less than that of adrenalectomized mice (non-restraint) under cold-stress. 4) The rectal temperature of normal and adrenalectomized mice that acclimated under cold stress ($0^{\circ}C$) for 5 and 10 days was usually higher than that of normal and adrenalectomized mice of non-acclimation under environment of $0^{\circ}C$. 5) The tolerance in mice under cold-stress was increased on the acclimtion of cold.

• Journal of Acupuncture Research
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• 제20권3호
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• pp.177-193
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• 2003

Objective : The present studies investigated the effects of 120Hz high frequency electroacupunctue(EA) on the stress-induced stomach dysfunction in relation to its effect on the level of stress hormone and gastric mucosal damages. The gastric mucosal injury was induced by cold-restraint stress and two acupoints corresponding to Zusanli and Sanyinjiao in man were used. Methods: Cold-restraint stress produced typical gastric lesions in all rats of the stressed groups, but he number of ulcers as well as the mean ulcer diameter were reduced by 120 Hz EA pre-treatment. The cold-restraint stress also induced an increase in catecholamine response involving epinephrine, norepinephrine and dopamine, but an slight decline were observed in EA pre-treated rats compared with cold-restrained rats. Results: The degranulation value of gastric mast cell was significantly higher in cold-restrained rats than in control ones. However, with the significant reduction of degranulation values of gastric mast cells in EA pre-treated rats compared with cold-restrained ones, $PGE_2$ content in the gastric mucosa of EA pre-treated rats was also different from that observed in cold-restrained rats. Cold-restraint stress induced an elevated mRNA expression of pro-inflammatory gene such as cyclooxygenases-2 and tumor necrosis factor(TNF)-${\alpha}$, but these expression were down-regulated in EA pre-treated rats. Immunohistochemecal analysis showed that while the inhibitory-${\kappa}B{\alpha}$ an TNF-${\alpha}$ immunoreaction in the surface epithelium of the stomach tended to increase, both reactions in the EA pre-treated rats showed similar pattern as observed in controls. Conclusions : These results suggest that 120 Hz EA may act as a therapeutical means for gastric mucosal damages through a activation of pituitary adrenal system. it could be concluded that 120 hz high frequency electroacupuncture affords a good protective potential against stress-induce gastrointestinal dysfunction.

• Korean Journal of Acupuncture
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• 제21권4호
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• pp.101-115
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• 2004

Objective : The present studies investigated the effects of 120 Hz high frequency electroacupuncture (EA) on the stress-induced stomach dysfunction in relation to its effect on the level of stress hormones and gastric mucosal damages. The gastric mucosal injury was induced by cold-restraint stress and two acupoints corresponding to Zusanli and Sanyinjiao in man were used. Methods : Cold-restraint stress produced typical gastric lesions in all rats of the stressed groups, but the number of ulcers as well as the mean ulcer diameter were reduced by 120 Hz EA pre-treatment. Results : The degranulation value of gastric mast cell was significantly higher in cold-restrained rats than in control ones. However, with the significant reduction of degranulation values of gastric mast cells in EA pre-treated rats compared with cold-restrained rats. Cold-restarint stress induced an elevated mRNA expression of pro-inflammatory gene such as cyclooxygenases-2 and tumor necrosis factor $(TNF)-{\alpha}$, but these expression were down-regulated in EA pre-treated rats. Immunohistochemical analysis showed that while the $inhibitory-{\kappa}B{\alpha}$ and $TNF-{\alpha}$ immunorection in the surface epithelium of the stomach tended to increase, both reactions in the EA pre-treated rats showed similar pattern as observed in controls. Conclusion : These results suggest that 120 Hz EA may act as a therapeutical means for gastric mucosal damages through an activation of pituitary adrenal system. It could be concluded that 120 Hz high frequency electroaucupuncture affords a good protective potential against stress-induced gastrointestinal dysfunction.

• Steel and Composite Structures
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• 제23권3호
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• pp.331-338
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• 2017

Cold-formed lipped channel columns (CFLCCs) have been widely used in light gauge steel constructions. The distortional buckling is one of the important buckling modes for CFLCCs and the distortional buckling critical load depends significantly on the rotational restrain stiffness generated by the web to the lipped flange. First, a simplified explicit expression for the rotational restraint stiffness of the lipped flange has been derived. Using the expression, the characteristics of the rotational restraint stiffness of the lipped flange have been investigated. The results show that there is a linear coupling relationship between the applied forces and the rotational restraint stiffness of the lipped flange. Based on the explicit expression of the rotational restraint stiffness of the lipped flange, a simplified analytical formula has been derived which can determine the elastic distortional buckling critical stress of the CFLCCs subjected to axial compression. The simplified analytical formula developed in this study has been shown to be accurate through the comparisons with results from the distortional buckling analyses using the ANSYS finite element software. The developed analytical formula is easy to apply, and can be used directly in practical design and incorporated into future design codes and guidelines.

• 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.

• Journal of Advanced Marine Engineering and Technology
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• 제11권3호
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• pp.45-52
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• 1987

Generally the factors affected largely by the cold cracking sensitivity of the weld are the quantity of the diffusible hydrogen, the brittleness and hardness of the bond area and the tensile restraint stress. These factors have relation each other, and if we can reduce one of these factors, it becomes instrumental to the root cracks prevention of weld. This study deals with the gravity type-underwater-welding of KR Grade A-3 marine steel plate using E4303 welding electrode in order to compare wet-underwater-welding with in-air- welding, resulting in obtaining the tensile restraint characteristics, the hardness distribution, the quantity of diffusible hydrogen and the macro- and micro-crack properties in both underwater and in-air welds. The main results obtained are as follows: 1) The quantity of diffusible hydrogen measured for 48 hours is about 18cc/100g-weld-metal for the in-air-weld of one pass and about 48cc/100g-weld-metal for the underwater-weld of one pass which is about 3 times penetration of diffusible hydrogen compairing with the case of the in-air-weld. However, it was experimentally confirmed that, by the multi-pass welding of 2 to 5 passes, the diffusible hydrogen in the underwater weld metal can be reduced as much as 27 to 49%. 2) The hardness of the weld metal indicates the highest value in the heat affected zones of underwater weld for more rapid cooling rate, resulting in the higher sensitivity of cold cracking. So, it is desirable to soften the higher hardness in the HAZ by tempering effect such as the multi-pass welding in the underwater welding. 3) At the bond vicinity of the underwater weld HAZ, micro cracks were found as resulted by both more rapid cooling rate and more diffusible hydrogen and also by the stress corrosion cracking under the tensile restraint stress in the underwater. But this could be prevented by the tempering effect of the following weld bead such as the multi-pass welding.

• 사상체질의학회지
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• 제20권3호
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• pp.151-163
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• 2008

1. Objective This study was done to identify the anti-stress effect of Hyeongbangdojeok-san (HDS), Yanggyeoksanhwa-tang(YST) in Soyangin. 2. Methods Experimental animals were composed of YST, HDS+stress groups which were administered each by 200mg/kg, 400mg/kg and the Saline+stress group. On the 1st day, making the rats forced swim and on the 2nd day, applying Forced swimming test to the rats. After FST, the levels of Corticosterone in the blood were measured. For the study of learning retardation, memory ability and anxiety reaction, experimental animals were composed of YST, HDS+restraint stress groups which were administered each by 400mg/kg, no stress group and the Saline+restraint stress group. Restraint stress were applied 2 hours a day for 3 weeks. On the last day of the 3rd week, Elevated Plus Maze(EPM) was applied to the groups and Morris Water Maze(MWM) was applied to the groups for 7 days. 3. Results 1. As the results of measuring FST which reflects depression, the YST+stress group and the HDS+stress group showed significant effect in comparison with the Saline+stress group. The levels of Corticosterone in the blood were decreased only in the 400mg/kg YST+stress group. 2. As the results of measuring how long EPM which reflects anxiety reaction stayed in the open arm, there was the trend which can suppress anxiety reaction in the HDS+restraint stress group bur no statistical significance. But there was any suppression of anxiety reaction in the YST+restraint stress group. 3. According to the result of MWM, the saline+restraint stress group showed the learning retardation which means increased time arriving at goal compared to the normal group at the second and third day of measurement. On the contrary, a learning retardation was significantly decreased in the YST+restraint stress group at the third day of measurement. 4. Among the Probe trial test a memory loss occurred in the saline+restraint stress group, but memory ability was significantly increased in the YST+restraint stress group. 4. Conclusion: As the results above, Soyangin Yanggyeoksanhwa-tang has significant influence to the antidepression effect, the learning retardation, the anxiety reaction and also in the Hormone level. Hyeongbangdojeok-san has significant influence to the antidepression effect, in the Hormone level, bur not to the learning retardation and anxiety reaction. prefer to drink cold water, and who are suffering from chronic gastritis.

• 대한기계학회논문집
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• 제16권4호
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• pp.658-666
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• 1992

본 연구에서는 고속, 연속장업으로 이루어지고 있는 스템핑 공정에서 금형과 강판간의 접촉-슬립에 따른 마찰 및 윤활특성의 성능을 평가할 수 있도록 한 원형단면 형상의 드로오비드 마찰실험장치를 활용하여 가압력, 윤활유 특성, 드로잉 속도와 강 판의 표면특성 등에 따른 자동차용 냉연강판과 도금강판의 마찰계수와 드로오비드 저 항력에 대한 테이터 베이스를 구축하고자 한다.

• Structural Engineering and Mechanics
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• 제49권2호
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• pp.147-161
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• 2014

In this paper a nonlinear finite element analysis model is established for cold-formed steel zed-section purlins subjected to uplift loading. In the model, the lateral and rotational restraints provided by the sheeting to the purlin are simplified as a lateral rigid restraint imposed at the upper flange-web junction and a rotational spring restraint applied at the mid of the upper flange where the sheeting is fixed. The analyses are performed by considering both geometrical and material nonlinearities. The influences of the rotational spring stiffness and initial geometrical imperfections on the uplift loading capacity of the purlin are investigated numerically. It is found that the rotational spring stiffness has significant influence on the purlin performance. However, the influence of the initial geometric imperfections on the purlin performance is found only in purlins of medium or long length with no or low rotational spring stiffness.

• 한국건축시공학회지
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• 제19권2호
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• pp.123-130
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• 2019

환경부하저감 및 동절기 시공의 효율을 위해 환경부하저감형 한중콘크리트 시공기술로서 고로슬래그시멘트와 내한촉진제를 병용한 콘크리트에 있어 열화의 기점이 되는 수축균열에 관해 검토했다. 그 결과, 고로슬래그시멘트 및 내한촉진제를 첨가함으로서 자유수축변형량 및 동일재령에 있어서 균열포텐셜은 증가하는 경향으로 구속조건하에서의 균열의 발생도 빠른 것을 확인할 수 있었다. 이것은, 자유수축변형량의 증가와 함께 크리프에 의한 응력 이완량의 감소나 구속도의 증가 등이 원인으로서 생각할 수 있으며, 동절기 시공에 있어서 고로슬래그 및 내한촉진제를 적용할 때는 수축에 의한 균열발생에 대해 검토할 필요가 있다고 판단된다.