• Biomolecules & Therapeutics
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• v.22 no.5
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• pp.420-425
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• 2014

Esophageal reflux of gastric contents causes esophageal mucosal damage and inflammation. Recent studies show that oxygen-derived free radicals mediate mucosal damage in reflux esophagitis (RE). Chlorogenic acid (CGA), an ester of caffeic acid and quinic acid, is one of the most abundant polyphenols in the human diet and possesses anti-inflammatory, antibacterial and anti-oxidant activities. In this context, we investigated the effects of CGA against experimental RE in rats. RE was produced by ligating the transitional region between the forestomach and the glandular portion and covering the duodenum near the pylorus ring with a small piece of catheter. CGA (10, 30 and 100 mg/kg) and omeprazole (positive control, 10 mg/kg) were administered orally 48 h after the RE operation for 12 days. CGA reduced the severity of esophageal lesions, and this beneficial effect was confirmed by histopathological observations. CGA reduced esophageal lipid peroxidation and increased the reduced glutathione/oxidized glutathione ratio. CGA attenuated increases in the serum level of tumor necrosis factor-${\alpha}$, and expressions of inducible nitric oxide synthase and cyclooxygenase-2 protein. CGA alleviates RE-induced mucosal injury, and this protection is associated with reduced oxidative stress and the anti-inflammatory properties of CGA.

• International Journal of Fluid Machinery and Systems
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• v.8 no.1
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• pp.1-12
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• 2015

In cardiopulmonary support systems with a membrane oxygenation such as a percutaneous cardiopulmonary support (PCPS) or an extracorporeal membrane oxygenation (ECMO), blood pumps need to generate the pressure rise of approximately 200mmHg or higher, due to the high hydraulic resistances of the membrane oxygenation and of the cannula tubing. In order to realize the blood pump with higher pressure rise, higher anti-hemolysis and thrombosis performances, the development of novel centrifugal blood pump composed of two-stage has been conducted by the authors. In the present paper, effective attempts to decrease the wall shear stress and to suppress the stagnation are introduced for the prevention of hemolysis and thrombosis in blood pumps. The hemolysis test was also carried out and it was clarified that the decrease of wall shear stress is effective as a guideline of design of blood pumps for improving the anti-hemolysis performance.

• Journal of the Society of Naval Architects of Korea
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• v.49 no.6
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• pp.541-549
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• 2012

The study adopted a freezing prevention method of the upper deck which used heating coil, and carried out numerical analysis by using ANSYS 13.0 CFD for design guide of the vessel operating in cold region. It is based on the experimental results of the anti-icing performance tests which were carried at cold room chamber in MOERI. Numerical analysis for the design guide was performed by considering S.S.T. (Shear Stress Transport) turbulent model for flow separation effects and the turbulence which occurred in interfaces of the numerical model in order to express appropriate heat transmission phenomenon. The numerical result shows average temperature of the upper deck surface appeared similarly compared with the indoor chamber test. The design guide for optimum freezing prevention presented through heat transmission capability and interval of the heat coil in various outdoor temperature($10^{\circ}C{\sim}-30^{\circ}C$) and wind speed(1m/s~7m/s).

• Molecules and Cells
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• v.46 no.3
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• pp.165-175
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• 2023

The transcription factor Nrf2 was originally identified as a master regulator of redox homeostasis, as it governs the expression of a battery of genes involved in mitigating oxidative and electrophilic stress. However, the central role of Nrf2 in dictating multiple facets of the cellular stress response has defined the Nrf2 pathway as a general mediator of cell survival. Recent studies have indicated that Nrf2 regulates the expression of genes controlling ferroptosis, an iron-and lipid peroxidation-dependent form of cell death. While Nrf2 was initially thought to have anti-ferroptotic function primarily through regulation of the antioxidant response, accumulating evidence has indicated that Nrf2 also exerts anti-ferroptotic effects via regulation of key aspects of iron and lipid metabolism. In this review, we will explore the emerging role of Nrf2 in mediating iron homeostasis and lipid peroxidation, where several Nrf2 target genes have been identified that encode critical proteins involved in these pathways. A better understanding of the mechanistic relationship between Nrf2 and ferroptosis, including how genetic and/or pharmacological manipulation of Nrf2 affect the ferroptotic response, should facilitate the development of new therapies that can be used to treat ferroptosis-associated diseases.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.5
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• pp.2845-2850
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• 2013

Background: Breast cancer is one of the most frequent diseases in women today. Little information exists on modifiable lifestyle factors including effects of ginger supplements (as an anti-oxidant and anti-inflammatory herbal) and water-based exercise on biomarkers related to oxidative stress such as malondialdehyde (MDA), nitric oxide (NO) and glutathione peroxidase (GPx) and adiponectin in obese women with breast cancer. The aim of this study was to determine the single and concomitant effect of 6-wks water-based exercise and oral ginger supplement on the aforesaid markers in obese women with breast cancer. Materials and Methods: Forty women diagnosed with breast cancer ($48{\pm}5.4$ years, $76{\pm}9$ kg, fat mass $41.8{\pm}4%$), volunteered to participate in the study. Subjects were randomly assigned into four groups; placebo, water-based exercise, ginger supplement and water-based exercise+ginger supplement groups. Subjects in the ginger supplement group and the water-based exercise+ginger supplement group orally received 4 capsules (each capsule contained 750 mg), 7 days a week for 6 weeks. The water-based exercise program featured progressive increase in intensity and time, ranging from 50% to 75% of heart rate reserve, in a pool with 15 meters width, 4 times a week for 6 weeks. Fasting blood samples were collected at pre-test and post-test time points. Results: The ginger supplementation and or the water-base exercise resulted in an increase of adiponectin, NO and GPx and reduction MDA, as compared to pre-test values. However, the combined intervention (water-base exercise and ginger supplement) group showed significantly a far better effect on the biomarkers related to oxidative stress and adiponectin levels, as compared to the waterbase exercise or ginger supplement alone groups and the age-matched placebo group. Conclusions: Our results revealed that water-base exercise is a non-drug therapeutic strategy to reduce systemic stress in obese women suffering from breast cancer. Further, ginger supplementation alone or in combination with training, also play an important role in the pathogenesis of oxidative stress in obese women diagnosed with breast cancer.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.37 no.1
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• pp.17-28
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• 2024

Objectives : This study was conducted to reveal the scientific mechanism of the anti-skin aging activity of Kyung-Ok-Ko(KOK), which is highly useful as a Korean traditional medicine and functional food. Methods : The skin wrinkle and aging inhibitory activity of KOK was confirmed through in vitro experiments of human dermal fibroblast neonatal cell(HDFn) and in vivo of C. elegans, and hairless mouse(SKH-1). Results : The amount of the C-terminus of the collagen precursor in the HDFn cell culture medium treated with KOK using an enzymes-linked immunoassay kit. The group treated with KOK 200㎍/㎖ was a 28.3% increase of collagen precursor compared to the control group. KOK showed inhibitory activity of MMP-1 compared to the control group at a concentration of 200㎍/㎖. In addition, KOK 200㎍/㎖ showed significant inhibitory activity of thermal stress and an oxidative stress compared to the control group in C. elegans. Furthermore, KOK showed a concentration-dependent(100mg/kg and 500mg/kg) anti-wrinkle formation effect in UV-irradiated hairless mouse(SKH-1). Additionally, when KOK was administered to UV-irradiated hairless mice, an increase in procollagen -1 and -3 genes expression was observed, and mmp-1 and mmp-9 genes, which increase collagen decomposition, decreased with the administration of KOK. Conclusions : The skin aging inhibition mechanism of Kyung-Ok-Ko(KOK) is presumed to be achieved through suppressing thermal stress and oxidative stress, suppressing mmp-1 and mmp-9 genes, and increasing procollagen-1 and procollagen-3.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.4
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• pp.312-318
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• 2016

This study examined the influence of a Mindfulness Based Compassion Meditation Program on the brain activation and stress of elderly women who experienced loss of spouse using 2 channel EEG (Electroencephalography). The total number of subjects was 60, consisting of elderly women aged from 65~75years of in Y county; 30 in the experimental group and 30 in the control group who were checked by EEG before and after the study. The study was conducted from August to November, 2015. The Mindfulness Based Compassion Meditation Program was designed for the convergence of body and mind integration with compassion meditation for the purpose of developing love, sympathy, and compassion. The treatment was conducted once a week, for 60 minutes at a time, over a period of 16 weeks. The results in the experimental group showed an increase in the Activity Quotient (ATQ) Rt(82.51/85.83, p<.013) and AntiStress Quotient (ASQ) Lt (74.711/71.17, p<.050). The Activity Quotient shows the mental function and behavior tendency in the brain, while the AntiStress Quotient shows the state of physical and mental relaxation. The Mindfulness Based Compassion Meditation Program was shown to influence the brain activation and stress of the elderly women using the practical application of neuroscience.

• Biomolecules & Therapeutics
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• v.11 no.4
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• pp.249-256
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• 2003

Pyroligneous liquid(PL) is produced by carbonizing Oak in 350-40$0^{\circ}C$. It is traditionally used for treating stress-related disorder, hepatic disease, immune disorder, G-I disorder and inflammatory disease. The aim of this study is to investigate anti-stress effects of PL. The experiments were performed with the use of young(9 weeks of age) male rats of SD strain and the male ICR mice (20-25 g). Animals of the normal group were not exposed to any stress and the control group were exposed to stress. The rats of the Ginseng, diazepam(BZ) and PL supplementary group were orally administered once a day 100 g of Ginseng extract-kg body weight, 5 mg of BZ/kg body weight and 1 ml of PL100 g body weight and then exposed to stress. The mice of the Ginseng, BZ and PL supplementary group were given water containing 100 g of Ginseng extract/100 ml potable water, 5 mg of BZ/kg 100 ml of drinking water and 10 ml of PL/100 ml of drinking water and exposed to stress. Animals were given materials for 7 days after stabilizing them, and then were given supplementary materials for 5 days with stress. They were stressed by immobilization for 30 minutes and then the animals were exposed to electroshocks for 5 minutes. We recorded stress-related behavioral changes of experimental animals by stressing them using the Etho-vision system and measured the levels of corticosterone in blood While stress suppressed locomotor activity of animals, PL-supplementation partially blocked the stress effect of locomotion in rats and mice, and also partially blocked stress-induced behavioral changes such as freezing, burrowing, smelling and rearing activity in rats and freezing, grooming, tailing and rearing in mice. The staying time of stressed rats and mice in open area decreased and in closed area it increased relatively in elevated plus maze test. However, these changes also partially were blocked by PL-supplementation. PL-supplementation decreased levels of blood corticosterone increased by stress in rats. These results suggest that PL protects partially the living organism from stress attack in some cases.

• Korean Journal of Food Science and Technology
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• v.29 no.1
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• pp.167-172
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• 1997

Effect of combined preparation (DWP715) containing Alaska pollack extract, maltol, ascorbic acid and nicotinamide on decreasing of blood alcohol was evaluated in human blood. Treatment of DWP715 prior to administration of 25% alcohol (100 mL) decreased alcohol concentration in blood and showed significant difference after 2 hours. The pharmacokinetic parameters such as area under the concentration-time curve (AUC), $C_{max},\;T_{max}\;and\;T_{1/2}$ were also decreased and delayed when compared with control values. Effects of DWP715 on anti-fatigue and anti-oxidation activities were also studied in the restraint stress model using various parameters (GOT, GPT, LDH values and organ weights) on mild condition and examined through the content of lipid peroxide induced by 2% $CCl_4$ in mouse livers. While GPT level, thymus and adrenal weight were not influenced by DWP715 dosing, LDH, GOT level and spleen weight used as a parameter against fatigue and stress states were recovered almost to the nomal level. Furthermore, lipid peroxidation due to $CCl_4$ was significantly inhibited by DWP715 treatment. These results suggest that DWP715 seems to metabolize the blood alcohol rapidly and to restore the damaged liver and fatigue conditions which was caused by alcohol metabolism to normal condition.

• Journal of Mechanical Science and Technology
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• v.17 no.6
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• pp.854-859
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• 2003

In this paper, we examine the singular stresses and electric fields in a functionally graded piezoelectric ceramic strip containing an eccentric crack off the center line under anti-plane shear loading with the theory of linear piezoelectricity. It is assumed that the properties of the functionally graded piezoelectric ceramic strip vary continuously along the thickness. Fourier transforms are used to reduce the problem to the solution of two pairs of dual integral equations, which are then expressed to a Fredholm integral equation of the second kind. Numerical values on the stress intensity factor and the energy release rate are obtained.