• 생약학회지
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• 제25권1호
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• pp.51-58
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• 1994

The studies were conducted to investigate the anti-diabetic activities on the hyperglycemia induced by streptozotocin in rats, anti-hypertensive activities in SHR, anti-fatigue and decrease of body weight activities in mice by Kyung Ok-Ko water extract and drink, which is a traditional preparation in Korea. 1. The blood glucose levels of streptozotocin-induced hyperglycemic rats were dose-dependently decreased by administrations of various doses(300, 600, 1200 mg/kg) of Kyung Ok-Ko water extract. Particularly, administration of 600, 1200 mg/kg were significantly shown to decrease glucose levels comparing with control group. 2. The serum total cholesterol levels of streptozotocin-induced hyperglycemic rats were dose-dependently decreased by administrations of various doses(300, 600, 1200 mg/kg) of Kyung Ok-Ko water extract. Particularly, administration of 600, 1200 mg/kg were significantly shown to decrease total cholesterol levels comparing with control group. 3. The serum triglyceride levels of streptozotocin-induced hyperglycemic rats were dose-dependently decreased by administrations of various doses(300, 600, 1200 mg/kg) of Kyung Ok-Ko water extract. Particularly, administration of 600, 1200 mg/kg were significantly shown to decrease triglyceride levels comparing with control group. 4. The blood pressure in SHRs were dose-dependently lower descended by administration of Kyung Ok-Ko water extract 300, 600, and 1200 mg/kg, respectively. 5. The swimming time of Kyung Ok-Ko water extract(100, 200, 400 mg/kg) and drink(0.7, 1.4, 2.1 ml/kg) were significantly extended to all experimental group dose-dependantly. 6. The decrease of body weight of Kyung Ok-Ko water extract(100, 200, 400 mg/kg) and drink(0.7, 1.4, 2.1 ml/kg) were significantly evaluated dose-dependently in all experimental group.

• 콘크리트학회지
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• 제6권6호
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• pp.143-150
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• 1994

교량의 확폭공사에는 대개 기설부와 신설부 교량을 일체화시키는 접합시공법이 행해지고 있다. 그러나 접합시공법은 설계 및 시공상 여러 가지 복합적인 문제를 야기시킨다. 본 연구는 피로실험을 통하여 접합시공에 따른 제반 문제점중 확폭교량 시공방법에 따른 휨피로거동과 콘크리트 양생시 기설부 교량을 통과하는차량에 의해 발생하는 진동이 신설부 교량에 미치는 영향을 조사하고자 실시하였다. 연구결과, 초기에 접합부 철근에서 약간을 응력집중현상 및 철근과 콘크리트간에 슬립현상이 관찰되었으나 전체적인 거동은 유사하였으며, 무수축합시공법이 신설부 교량의 콘크리트 양생중 발생하는 진동의 영향을 완화시킬 수 있음을 알 수 있었다.

• 한국해양공학회지
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• 제23권2호
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• pp.74-80
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• 2009

Surface hardening treatments, such as using the high-frequency induction hardening method, are widely used to increase the fatigue life and prevent the failure of materials by locally increasing the surface hardness. This method, in particular, brings an improvement in static strength by compressive residual surface stress due to the hardening. In this study, the mechanical properties of high-frequency induction hardened SCM440 steel were investigated. These results were also compared with those for base metal and a Q/T (tempering after quenching) treatment specimen. The test results showed that partially high-frequency induction hardened SCM440 steel specimens were more improved in static strength, surface hardness, fatigue limit, and anti-wear than the base metal and Q/T treatment specimens. In particular, the fatigue limit of the high-frequency induction hardened SCM440 steel increased by more than about 52% compared to that of base metal and by about 25% compared to that of the Q/T specimen.

• 동력기계공학회지
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• 제7권2호
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• pp.66-72
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• 2003

Recently, the steel parts used at the aerospace and automobile industries are required to be used light weight parts. Therefore, used material, steel have to be a high stress, which is an indispensable condition in this field. At the consideration of parts design, high hardness of the lightweight parts have an benefit of saving fuel and material. A high stress of metal has a point of difference according to the shape of design, external cyclic load and condition of vibration. A crack generates on the surface of metal or under yield stress by defect of inner metal defect or surface defect and slowly, this crack grow stable growth. Finally, rapidity failure phenomena is happen. Fatigue failure_phenomena, which happen in metal, bring on danger in human life and property therefor, anti-fatigue failure technology take an important part of current industries Currently, the shot peening is used for removing the defect from the surface of steel and improving the fatigue strength on surface. Therefore, this paper investigated the effect on frcature toughness using shot peening which is improve the resistance of crack growth and crack expansion rate by fatigue that make a compressive residual stress on surface.

• 대한안전경영과학회지
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• 제15권4호
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• pp.153-160
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• 2013

The purpose of this study was to compare biomechanical factors on badminton shoes between anti-slip outsole and non anti-slip outsole. Six subjects participated in this experiment. For three-dimensional analysis, eight cameras (Oqus 3series, Qualisys) were used to acquire raw data, and then the parameters were calculated and analyzed with Visual-3D. In conclusion, the patterns of spent time during side step, and maximum velocities of CoGs were consistent without joint angles of lower extremities in spite of small differences. Those of GRFs, and moment of lower extremities were absolutely consistent. This trend of biomechanical factors was that Y shoe (ante-treatment) was much greater and PS shoe (treatment) was greater than Y shoe (treatment). (That was, Y shoe (ante-treatment) > PS shoe (treatment) >Y shoe (treatment)). The findings of this study showed that anti-slip outsole was effective and brought increasing performance and decreasing injuries. It is suggested that further study of these phenomena will help understand many aspects of human locomotion, including work, performance, fatigue and possible injuries.

• 셀메드
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• 제8권3호
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• pp.14.1-14.6
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• 2018

Santalum album Linn. [Family: Santalaceae] is commonly known as white sandalwood, sandal safaid and safed chandan. It is one of the most valuable trees and second costliest wood in the world. Sandalwood and its oil is extensively used in the Unani and other traditional systems of medicine as it has blood purifier, anti-inflammatory, analgesic, exhilarant, cardiotonic, antiseptic, nervine tonic and expectorant properties. It is used in skin, cardiac, liver, gastrointestinal, respiratory, integument and urogenital disorders. These uses are supported and proven by many in vitro or in vivo studies. The proven pharmacological activities of S. album are antimicrobial, anti-oxidant, anti-inflammatory, antimutagenic and anti-fatigue. The research has proven that sandal oil or its constituents have anti-microbial activity. Sandalwood oil showed skin cancer preventive effect in mice and its constituent alpha santalol showed the anticancer property. The methanolic extract of wood was confirmed for antioxidant, free radical scavenging, analgesic and anti-inflammatory activities. ${\alpha}$ and ${\beta}$ santalols present in sandal oil showed sedative effects. Sandalwood tea had a significant effect on heart muscles of frog and showed increased myocardial contractility. Its oil showed significant changes in hepatic xenobiotic metabolizing enzymes. Sandalwood oil and its major constituents showed less acute oral and dermal toxicity in laboratory animals. Hence, the aforementioned studies justify the uses of sandalwood and its oil mentioned in the classical Unani literature. However, further clinical trials are suggested to confirm its efficacy and safety in humans.

• Nutrition Research and Practice
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• 제17권4호
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• pp.670-681
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• 2023

BACKGROUND/OBJECTIVES: Oxidative stress is caused by reactive oxygen species and free radicals that accelerate inflammatory responses and exacerbate fatigue. Tormentic acid (TA) has antioxidant and anti-inflammatory properties. Thus, the aim of present study is to determine the fatigue-regulatory effects of TA in H₂O₂-stimulated myoblast cell line, C2C12 cells and treadmill stress test (TST) and forced swimming test (FST) animal models. MATERIALS/METHODS: In the in vitro study, C2C12 cells were pretreated with TA before stimulation with H₂O₂. Then, malondialdehyde (MDA), lactate dehydrogenase (LDH), creatine kinase (CK) activity, tumor necrosis factor (TNF)-α, interleukin (IL)-6, superoxide dismutase (SOD), catalase (CAT), glycogen, and cell viability were analyzed. In the in vivo study, the ICR male mice were administered TA or distilled water orally daily for 28 days. FST and TST were then performed on the last day. In addition, biochemical analysis of the serum, muscle, and liver was performed. RESULTS: TA dose-dependently alleviated the levels of MDA, LDH, CK activity, TNF-α, and IL-6 in H₂O₂-stimulated C2C12 cells without affecting the cytotoxicity. TA increased the SOD and CAT activities and the glycogen levels in H₂O₂-stimulated C2C12 cells. In TST and FST animal models, TA decreased the FST immobility time significantly while increasing the TST exhaustion time without weight fluctuations. The in vivo studies showed that the levels of SOD, CAT, citrate synthase, glycogen, and free fatty acid were increased by TA administration, whereas TA significantly reduced the levels of glucose, MDA, LDH, lactate, CK, inflammatory cytokines, alanine transaminase, aspartate transaminase, blood urea nitrogen, and cortisol compared to the control group. CONCLUSIONS: TA improves fatigue by modulating oxidative stress and energy metabolism in C2C12 cells and animal models. Therefore, we suggest that TA can be a powerful substance in healthy functional foods and therapeutics to improve fatigue.

• 동의생리병리학회지
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• 제18권6호
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• pp.1762-1768
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• 2004

The Korean formula medicine, Gami-Yukmi-Jihwang-Tang (GYJT) has been used for growing slowly, short of stature, incomplete development, fatigue, weak child, growing pain of child. However, it is still unclear how GYJT has an effect on experimental models. In the present study, the author investigated the immune-enhancing effect of GYJT. Forced swimming test (FST) was performed as a model of activity test in mice and measured blood urea nitrogen (BUN), aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactic dehydrogenase (LDH), glucose (Glc) and total protein (TP) in the serum. GYJT (1, 0.1 and 0.01 g/㎏) were orally administered to mice, once per day for 7 days using a feeding atraumatic needle. After 3 days, on FST, the immobility time was significantly decreased in the GYJT (0.01g/㎏/day)-fed group (120.75±5.71s) in comparison with the saline-fed group (153.80±10.74s). After 7 days, the immobility time was significantly decreased in the GYJT (0.1 and 0.01g/㎏/day)-fed group (125.67±5.36s and 107.67±3.71s) in comparison with the saline-fed group (167.67±12.99s). In addition, the contents of BUN and Glc in the blood serum were significantly decreased and the contents of AST, ALT and LDH were also decreased in the GYJT (1g/㎏/day)-fed group. However, the content of TP was not changed. The present results suggest that GYJT may be useful for the anti-fatigue and immune-enhancing agent. Also, the author investigated the effect of GYJT on the production of cytokines in human T-cell line, MOLT-4 cells. However, GYJT has not affected the production of IFN­γ, IL-2, IL-4. These results suggest that GYJT has immune-enhancing effect but does not affect T cell-mediated production of cytokines in the immune function improvement.

• 대한한의학방제학회지
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• 제15권2호
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• pp.35-45
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• 2007

Objective : The purpose of this report was to provide the information activity and safety of Palmul-tang by analyzing domestic/international papers and theses about Palmul-tang, Methods: Domestic/international papers and theses related to Palmul-tang were reviewed and analyzed, These papers were then classified by year, experimental method and subject, Results: The following results were obtained in this study. 1. The study of Palmul-tang started from 1985 and was continuously increased. The study was mainly forcused on experimental model rather than clinical study. 2. As these studies were classified by subject, papers related to immune intensification were most abundant by 20 papers, Besides there were several papers related to cardiovascular activity, reproductive activity, anti-apoptotic activity and cerebral hemodynamics. 3. Among the papers related to immune intensification. the studies on recovery of fatigue were mostabundant by 10 papers and the studies of on immune cell and cytokine express were six. In addition to. several studies were associated with anti-cancer activity and anti-allergic activity. Recovery of fatigue was determined by measurement of fatigue markers in a living body such as lactate. CPK, pyruvate and triglyceride and assessment of exercise capability of animals such as swimming test. slopped plate test. Rota-rod test, and activity cage test after Palmul-tang treatment. 4. According to experimental data. it is supported that Palmul-tang has been used as Qi and Blood intensifier with immune intensification and recovery of fatigue. 5. The paper related to safety of Palmul-tang was only one paper which is studied on acute toxicity of Palmul-tang with experiment with ICR mouse. There was no study on evaluating safety by observing liver and kidney functions after Palmul-tang treatment Conclusion: Palmul-tang is being used in various ways associating with immune intensification. cardiovascular activity and reproductive activity. However. studies on efficacy and mechanism of Palmul-tang should be conducted at the molecular biology level and studies on safety of Palmul-tang need to be completed at the clinical level.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.796-805
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• 2005

The tilting pad journal bearings have been widely used to support high pressure/high rotating turbine rotors owing to their inherent dynamic stability characteristics. However, fatigue damages in the upper unloaded pads and the break of locking pins etc. by pad fluttering are continuously taken place in the actual steam turbines. The purpose of this paper is to develop a new bearing model that can prevent bearing problems effectively by pad fluttering in a tilting pad journal bearing. A new bearing model which has a wedged groove is suggested from the studies of fluttering mechanism performed by previously research works. The fluttering characteristics of the upper unloaded pad are studied experimentally in order to verify the reliability of a new bearing model. It can be known that the phenomenon of pad fluttering nearly does not occurred in the new bearing model under the various experimental conditions. And it is observed that any kinds of bearing failures by pad fluttering does not detect in the application of acture steam turbines.