• Environmental Mutagens and Carcinogens
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• v.25 no.2
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• pp.71-75
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• 2005

Green tea and their major constituents such as catechins are famous materials for their anti-oxidative and anti-carcinogenic activity, but many compounds with reducing power can promote the oxidation in their oxidized form or in the presence of metal ion. We investigated the pro-oxidative effect of the ethanol extract equivalent up to 30mg of dried weight of green tea leaves in four in vitro systems which could be used for detecting DNA damage. Although ethanol extract of green tea did not show significant mutagenicity in Salmonella typhimurium TA102, which is sensitive strain to oxidative stress, it degraded deoxyribose extensively in the presence of $FeCl_3-EDTA$ complex, promoted 8-oxoguanine formation in the live bacteria cell, Salmonella typhimurium TAI04, and cleaved super coiled DNA strand with the help of copper ion. It suggested that green tea, famous anti-oxidative material, can be pro-oxidant according to the condition of extraction or metal existence.

• Korean Journal of Pharmacognosy
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• v.48 no.3
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• pp.219-225
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• 2017

We investigated the anti-oxidative effect of the blueberry duke (Vaccinium corymbosum L., Ericaceae) ethanol extract in Caenorhabditis elegans model. The ethanol extract of blueberry duke showed relatively significant DPPH radical scavenging and superoxide quenching activities. To prove antioxidant activity of the extract, we checked the activities of superoxide dismutase (SOD), catalase, intracellular ROS, and oxidative stress tolerance in C. elegans. In addition, to verify if the increased stress tolerance of C. elegans by treating with the extract was due to regulation of stress-response genes, we checked SOD-3 expression using a transgenic strain. As a consequence, the blueberry duke ethanol extract increased SOD and catalase activities of C. elegans, and reduced intracellular ROS accumulation in a dose-dependent manner. Besides, blueberry duke ethanol extract-treated CF1553 worms showed higher SOD-3::GFP intensity.

• Biomolecules & Therapeutics
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• v.18 no.1
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• pp.24-31
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• 2010

Taurine, 2-aminoethanesulfonic acid, is an abundant free amino acid present in brain cells and exerts many important biological functions such as anti-convulsant, modulation of neuronal excitability, regulation of learning and memory, anti-aggressiveness and anti-alcoholic effects. In the present study, we investigated to explore whether taurine has any protective actions against oxidative stress-induced damages in neuronal cells. ERK I/II regulates signaling pathways involved in nitric oxide (NO) and reactive oxygen species (ROS) production and plays a role in the regulation of cell growth, and apoptosis. We have found that taurine significantly inhibited AMPA induced cortical depolarization in the Grease Gap assays using rat cortical slices. Taurine also inhibited AMPA-induced neuronal cell damage in MTT assays in the differentiated SH-SY5Y cells. When the neuronal cells were treated with $H_2O_2$, levels of NO were increased; however, taurine pretreatment decreased the NO production induced by $H_2O_2$ to approximately normal levels. Interestingly, taurine treatment stimulated ERK I/II activity in the presence of AMPA or $H_2O_2$, suggesting the potential role of ERK I/II in the neuroprotection of taurine. Taken together, taurine has significant neuroprotective actions against AMPA or $H_2O_2$ induced damages in neuronal cells, possibly via activation of ERK I/II.

• Structural Engineering and Mechanics
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• v.23 no.1
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• pp.63-74
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• 2006

In this paper, the scattering of harmonic elastic anti-plane shear waves by two collinear cracks in functionally graded materials is investigated by means of nonlocal theory. The traditional concepts of the non-local theory are extended to solve the fracture problem of functionally graded materials. To overcome the mathematical difficulties, a one-dimensional non-local kernel is used instead of a two-dimensional one for the anti-plane dynamic problem to obtain the stress field near the crack tips. To make the analysis tractable, it is assumed that the shear modulus and the material density vary exponentially with coordinate vertical to the crack. By use of the Fourier transform, the problem can be solved with the help of a pair of triple integral equations, in which the unknown variable is the displacement on the crack surfaces. To solve the triple integral equations, the displacement on the crack surfaces is expanded in a series of Jacobi polynomials. Unlike the classical elasticity solutions, it is found that no stress singularities are present at crack tips.

• Korean Journal of Pharmacognosy
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• v.49 no.4
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• pp.322-327
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• 2018

Methanol extract of Salvia miltiorrhiza Bunge (Labiatae) root was investigated to research the anti-oxidative activity, by using a Caenorhabditis elegans model system. The methanol extract of this plant showed significant DPPH radical scavenging and superoxide quenching activities. Ethyl acetate soluble fraction of the methanol extract that showed the most potent DPPH radical scavenging and superoxide quenching activities. The ethyl acetate fraction was tested on its activities of superoxide dismutase (SOD), catalase, and oxidative stress tolerance in C. elegans. Furthermore, in order to see if regulation of stress-response genes is responsible for the increased stress tolerance of the ethyl acetate fraction treated C. elegans, we checked SOD-3 expression using a transgenic strain. Consequently, the ethyl acetate fraction of S. miltiorrhiza root increased the catalase and SOD activities in a dose-dependent manner in C. elegans. Besides, the ethyl acetate fraction-treated CF1553 worms showed higher SOD-3::GFP intensity than the non-treated ones.

• The Korean Journal of Physiology and Pharmacology
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• v.23 no.5
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• pp.335-344
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• 2019

Obesity causes inflammation and impairs thermogenic functions in brown adipose tissue (BAT). The adipokine lipocalin 2 (LCN2) has been implicated in inflammation and obesity. Herein, we investigated the protective effects of caloric restriction (CR) on LCN2-mediated inflammation and oxidative stress in the BAT of high-fat diet (HFD)-fed mice. Mice were fed a HFD for 20 weeks and then either continued on the HFD or subjected to CR for the next 12 weeks. CR led to the browning of the white fat-like phenotype in HFD-fed mice. Increased expressions of LCN2 and its receptor in the BAT of HFD-fed mice were significantly attenuated by CR. Additionally, HFD+CR-fed mice had fewer neutrophils and macrophages expressing LCN2 and iron-positive cells than HFD-fed mice. Further, oxidative stress and mitochondrial fission induced by a HFD were also significantly attenuated by CR. Our findings indicate that the protective effects of CR on inflammation and oxidative stress in the BAT of obese mice may be associated with regulation of LCN2.

• Journal of Oriental Neuropsychiatry
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• v.9 no.2
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• pp.87-95
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• 1998

This study was aimed to evaluate the anti-stress effect of Soeuminsohabhyangwon on the mice in Cold and Swimming stress.In order to investigate the anti-stress effect of Soeuminsohabhyangwon in Cold and Swimming stressed mice, the serotonin contents were measured by HPLC method in various part of mouse brain The following results were observed. 1. In Cerebral Cortex of Frontal Lobe, the serotonin content was decreased in the Control group as compared with Normal group and the serotonin content was increased in the SHW group as compared with Control group. 2. In hypothalamus, the serotonin content was decreased in the Control group as compared with Normal group and the serotonin content was increased with statistical significance in the SHW group as compared with Control group. 3. In corpus striatum, the serotonin content was decreased in the Control group as compared with Normal group and the serotonin content was increased with statistical significance in the SHW group as compared with Control group. 4. In hippocampus, the serotonin content was decreased in the Control group as compared with Normal group and the serotonin content was increased with statistical significance in the SHW group as compared with control group.Base on the above results, it may be concluded that Soeuminsohabhyangwon are effective to reduce stress.

• The Journal of Internal Korean Medicine
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• v.22 no.4
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• pp.683-689
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• 2001

In order to study the anti-stress effect of hyangbujapalmultang, several measures of stress, including body weight changes, organ weight changes and catecholamine changes. The following result have been obtained: 1. The weight loss of contol group was $28.5{\pm}1.8g$, that of sample group was $20.3{\pm}1.6g$. This differance was statistcally significant. 2.The organ weight(Liver,Spleen,Kidney,Adrenal gland) was the only significant change in the spleen, in sample group comparing to control group. 3. The norepinephrine contents of control group was $695.5{\pm}22.7pg/ml$, that of sample group was $607.4{\pm}21.7pg/ml$. This shows significant difference in sample group comparing to contol group. 4. The epinephrine contents of control group was $212.8{\pm}9.8pg/ml$, that of sample group was $182.6{\pm}8.4pg/ml$. This shows significant differance in sample group comparing to control group. 5. The dopamine contents of control group was $504.5{\pm}31.3$, that of sample group was $463.4{\pm}27.8pg/ml$. This shows the value decreased, but none of it is significant. Based on avove results, it may be conculed that hyangbujapalmultang has anti-stress effects.

• The Journal of Korean Medicine
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• v.24 no.3
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• pp.23-34
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• 2003

Objective : In 2001, the rate of obesity in Korea reached 30.6%. There are many therapeutic ways to reduce body weight, such as low and very low calorie diet, exercise therapy, behavior modification therapy, etc. However, in many cases the patients feel stress under obesity treatment because of starvation. This study was aimed to evaluate the anti-starvation stress effect of Coicis Semen on mice. Methods : First, the mice were divided into 6 groups : Normal (group with no starvation), Control (administrated normal saline 6 times before starting 36 hours starvation), and Samples A, B, C, and D (administrated 0.25, 0.5, 1.0, 3.0 g/kg Coicis Semen respectively 6 times before starting 36 hours starvation). Then the plasma corticosterone level and rectal temperature were measured. The norepinephrine, dopamine, DOPAC (dihydroxy-phenylacetic acid), 5-HT (5-hydroxytryptamine) and 5- HIAA (5-hydroxy-indole-acetic acid) in the hypothalamus were measured by the HPLC method. Result : I. The rectal temperature in Sample group D showed a significant difference (P<0.05) compared with the Control group. 2. The DOPAC in Sample groups A, C and D showed the significant difference (P<0.05) compared with the Control group. Conclusion : It might be recognized that Coicis Semen has an anti-starvation stress effect.

• The KSFM Journal of Fluid Machinery
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• v.17 no.2
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• pp.12-23
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• 2014

A parametric study on anti-vortex holes for turbine blade cooling was investigated numerically. Three-dimensional Reynolds-averaged Navier-Stokes equations and shear stress transport turbulence model were used for analysis of anti-vortex film cooling. Validation of numerical results was carried out comparing with experimental data. The cooling performance of anti-vortex holes was assessed by two geometric variables, the ratio of diameters of holes and the lateral distances between the primary hole and anti-vortex hole at blowing ratios of 0.5 and 1.0. The results showed that the spatially-averaged film-cooling effectiveness increases as the ratio of the diameters increases and the distance between the primary hole and anti-vortex hole decreases.