• Biomolecules & Therapeutics
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• v.18 no.2
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• pp.219-225
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• 2010

We tested whether ginsenosides $Rg_3$-standardized ginseng extract (RGE) has anti-stress effects in restraint-stressed animals. RGE increased time spent in the open arms and open arm entries in the elevated plus-maze test. In addition, RGE blocked the reduction of center zone distance and stereotypes behaviors in the open-field test. RGE also increased head dips in stressed mice, indicating anxiolytic-like effects. Stress decreased movement distance and duration, burrowing, and rearing frequency but increased face washing and grooming. RGE significantly reversed burrowing and rearing activity in stressed mice. In addition, we measured sleep architecture in restraint stressed rats using EEG recorder. Stress increased rapid eye movement (REM) sleep, but total sleep and non-rapid eye movement (NREM) sleep were not changed. RGE did not affect sleep architecture in stressed rats. These behavioral experiments suggest that RGE has anti-stress effects in restraint-stressed animal models.

• Journal of Pharmacopuncture
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• v.20 no.4
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• pp.257-264
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• 2017

Introduction: Pharmacopuncture, which combines acupuncture with herbal medicine, is one of the newly developed acupuncture techniques that has recently been put into use. The possible mechanisms of scolopendra pharmacopuncture, as well as its potential effects on depressive symptoms, were investigated in this study by using a mouse model of chronic immobilization stress (CIS). Methods: C57BL/6 male mice were randomly assigned into three groups: mice not stressed with restraint and injected with distilled water, mice stressed with restraint and injected with distilled water, and mice stressed with restraint injected with scolopendra pharmacopuncture at a cervical site. Behavioral tests (an open field test, tail suspension test, and forced swimming test) were carried out after two weeks of CIS and injection treatments. The expression levels of glial fibrillary acidic protein (GFAP) in the hippocampus were determined by using western blot and immunohistochemistry analyses. Results: Mice exposed to CIS showed decreased behavioral activity, while scolopendra pharmacopuncture treatment significantly protected against the depressive-like behaviors induced by CIS. Moreover, scolopendra pharmacopuncture treatment increased GFAP protein levels in the hippocampi of the mice stressed by chronic immobilization. Conclusion: Scolopendra pharmacopuncture has an ameliorating effect on depressive behavior, which is partially mediated through protection against glial loss in the hippocampus.

• Structural Engineering and Mechanics
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• v.75 no.6
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• pp.675-684
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• 2020

An innovative retrofit method using pre-stressed steel strips and externally-bonded steel plates was presented in this paper. With the aim of exploring the seismic performance of the retrofitted RC interior joints, four 1/2-scale retrofitted joint specimens together with one control specimen were designed and subjected to constant axial compression and cyclic loading, with the main test parameters being the volume of steel strips and the existence of externally-bonded steel plates. The damage mechanism, force-displacement hysteretic response, force-displacement envelop curve, energy dissipation and displacement ductility ratio were analyzed to investigate the cyclic behavior of the retrofitted joints. The test results indicated that all the test specimens suffered a typical shear failure at the joint core, and the application of externally-bonded steel plates and that of pre-stressed steel strips could effectively increase the lateral capacity and deformability of the deficient RC interior joints, respectively. The best cyclic behavior could be found in the deficient RC interior joint retrofitted using both externally-bonded steel plates and pre-stressed steel strips due to the increased lateral capacity, displacement ductility and energy dissipation. Finally, based on the test results and the softened strut and tie model, a theoretical model for determining the shear capacity of the retrofitted specimens was proposed and validated.

• Steel and Composite Structures
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• v.7 no.1
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• pp.35-52
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• 2007

The cold formed light-gauge profiled steel sheeting can offer considerable shear resistance acting in the steel building frame. This paper conducted the full-scale test on the shear behavior of stressed skin diaphragm using profiled sheeting connected by the self-tapping screws. A three-dimensional finite element model that simulates the stressed skin diaphragm was developed. The sheet was modeled using thin element model while the supporting members were simulated using beam elements. Fasteners were represented in the numerical model as equivalent springs. A joint test program was conducted to characterize the properties of these springs and results were reported in this study. Finite element model of the full-scale test was analyzed by use of the ANSYS package, considering nonlinearity caused by the large deflection and slip of fasteners. The experimental data was compared with the results acquired by the EUR formulas and finite element analysis.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.761-764
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• 2008

The present study is aimed to study the effect of elevated temperatures ranging from 20 to $700^{\circ}C$ on the strain properties of high-strength concrete of 40, 60, 80MPa grade. In this study, the types of test were the stressed test and stressed residual test that the specimens are subjected to a 25% of ultimate compressive strength at room temperature and sustained during heating and when target temperature is reached, the specimens are loaded to failure. Or specimens are loaded to failure after 24hour cooling time. tests were conducted at various temperatures ($20{\sim}700^{\circ}C$) for concretes made with W/B ratios 46%, 32% and 25%. Test results showed that the relative values of elastic modulus decreased with increasing compressive strength grade of specimen and the axial strain at peak stress were influenced by the load before heating. thermal strain of concrete at high temperature was affected by the preload as well as the compressive strength.

• The Journal of Internal Korean Medicine
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• v.32 no.3
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• pp.411-424
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• 2011

Objectives : This study was performed to investigate the antifatigue effect of SM-2000 on fatigued and stressed people. Methods : This study was carried out on 23 healthy people who have fatigue and stress. 11 people as the mentally-stressed group were examined by subjective symptoms of fatigue and blood cortisol test. They drank SM-2000 for seven days. SM-2000 was made up herbs which were used for fatigue. After that they were again examined by subjective symptoms of fatigue and blood cortisol test. 12 people as the physically-fatigued group were examined with fatigue biomarkers and exercise test. They also drank SM-2000 for seven days. After that they were again examined with fatigue biomarkers and exercise test. Results : Cortisol level, subjective symptoms of fatigue scores and physical, mental, and neuro-sensory symptoms of fatigue scores after drinking SM-2000 were not significantly increased compared with before drinking SM-2000 in the mental stressed group. SM-2000 significantly decreased lactate, glucose, and phosphorous levels, and running time after drinking SM-2000 was significantly suppressed compared with before drinking SM-2000 in the physically-fatigued group. Conclusions : On the basis of these results, SM-2000 had a clinical antifatigue effect in physically-fatigued people.

• Journal of the Earthquake Engineering Society of Korea
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• v.17 no.5
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• pp.219-225
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• 2013

This work examines the feasibility for estimating existing tensile stress on a stressed wire using the permeability of magnetic flux. A closed magnetic circuit has been constructed to induce magnetic flux inside a steel wire. With different tension stress levels on a wire, the permeability of magnetic flux on the wire has been measured. Two different experimental case studies have been conducted for the examination of sensitivity of permeability of magnetic flux on the stressed wire. One is a varying-length stress test, and the other is a fixed-length stress test. The results show that the permeability of magnetic flux in the varying-length stress test is inversely proportional to the applied stress, while the permeability in the fixed-length stress test is linearly proportional to the applied stress on the stressed wire. It is thus expected that the permeability of magnetic flux on a wire can be a promising indicator for the inspection of its tensile stress.

• Journal of the Korea Concrete Institute
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• v.20 no.5
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• pp.583-592
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• 2008

Recently, the effects of high temperature on compressive strength, elastic modulus and strain at peak stress of high strength concrete were experimentally investigated. The present study is aimed to study the effect of elevated temperatures ranging from 20 to 700 on the material mechanical properties of high strength concrete of 40, 60, 80 MPa grade. In this study, the types of test were the stressed test and stressed residual test that the specimens are subjected to a 25% of ultimate compressive strength at room temperature and sustained during heating and when target temperature is reached, the specimens are loaded to failure. And another specimens are loaded to failure after 24 hour cooling time. Tests were conducted at various temperatures ($20{\sim}700^{\circ}C$) for concretes made with W/B ratios 46%, 32% and 25%. Test results showed that the relative values of compressive strength and elastic modulus decreased with increasing compressive strength grade of specimen and the axial strain at peak stress were influenced by the load before heating. Thermal strain of concrete at high temperature was affected by the preload level as well as the compressive strength. Finally, model equation for compressive strength and elastic modulus of heated high strength concrete proposed by result of this study.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.05a
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• pp.63-64
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• 2012

In case of concrete, it should be deformed by many factors, such as explosive spalling, thermal strain and creep at high temperature. Structural fire design has been proposed to predict fire damage as national standard. It is general safer to use values obtained from tests of unstressed residual test in stead of stressed test. But most of thermal properties on concrete were conducted with normal aggregate. In this study, it evaluated mechanical properties of concrete with aggregate type and loading condition. we use normal and light aggregate to have different thermal properties. Also, we test mechanical properties to use Ø100×200 mm cylinder specimen according to target temperature and 0%, 20%, 40% loading.

• Food Science and Biotechnology
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• v.27 no.6
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• pp.1801-1809
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• 2018

In the current study investigated the protective effects of citrus based mixture drinks (CBMDs) using oxidative stress in human dermal fibroblast (HDF) cells and restraint-stressed rats. The CBMDs contained citrus bioflavonoids including narirutin and hesperidin. The cell viability of HDF cells treated with $H_2O_2$ was observed at 53.9% but treated with CBMD-1 and CBMD-2 ($500{\mu}g/mL$) on $H_2O_2$ exposed HDF cells significantly increased the relative cell viability at 65.0 and 72.2%, respectively. In the treadmill test, the time spent on the electrode plate in the restraint-stressed group was analyzed 24.1 s, but restraint-stressed rats with administered CBMDs (300 mg/kg) had significantly decreased the time at 2.4 (CBMD-1) and 4.7 (CBMD-2) s, respectively. In addition, number of touches the electrode plate in restraint-stressed group was observed at 42.4 ea, but, restraint-stressed rats with administered CBMD-1 and CBMD-2 (300 mg/kg) were significantly decreased at 7.0 and 10.2 ea, respectively.