• 대한한방내과학회지
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• 제17권1호
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• pp.175-192
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• 1996

These studies were carried out to investigate the effect of Jungchuntang water extract on the inhibitory contractile action of acetylcholine in rat. The results of these studies were as follows; 1. Contractile force of acetylcholine from trachea smooth muscle in rat was significantly inhibited by Jungchuntang. 2. Dose-response of acetylcholine pretreated Jungchuntang in rat was not significantly changed. 3. Inhibitory contractile action of acetylcholine pretreated propranolol in rat was decreased. 4. Inhibitory contractile action of acetylcholine pretreated indomethacin was not significantly changed by Jungchuntang. 5. Inhibitory contractile action of acetylcholine pretreated methylene blue was significantly changed by Jungchuntang. 6. Contractile force of acetylcholine from trachea smooth muscle in rat was significantly inhibited by Jungchuntang. 7. Dose-response of acetylcholine pretreated Jungchuntang in rat was not significantly changed. 8. Inhibitory contractile action of acetylcholine pretreated propranolol in rat was decreased. 9. Inhibitory contractile action of acetylcholine pretreated indomethacin was not significantly changed by Jungchuntang. 10. Inhibitory contractile action of acetylcholine pretreated methylene blue was significantly changed by Jungchuntang.

• The Korean Journal of Physiology and Pharmacology
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• 제1권5호
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• pp.547-553
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• 1997

It has been known that activation of tyrosine kinases is involved in signal transduction. Role of the tyrosine kinase in vascular smooth muscle contraction was examined in deoxycorticosterone acetate (DOCA)-salt hypertensive rats. Male Sprague-Dawley rats underwent uninephrectomy, one week after which they were subcutaneously implanted with DOCA (200 mg/kg) and supplied with 1% NaCl and 0.2% KCl drinking water for $4{\sim}6$ weeks. Control rats were treated the same except for that no DOCA was implanted. Helical strips of carotid arteries were mounted in organ baths for measurement of isometric force development. Genistein was used as a tyrosine kinase inhibitor. Concentration-response curves to 5-hydroxytryptamine (5-HT) shifted to the right by genistein in both DOCA-salt hypertensive and control rats. Although the sensitivity to genistein was similar between the two groups, the maximum force generation by 5-HT was less inhibited by genistein in arteries from DOCA-salt hypertensive rats than in those from controls. Genistein-induced relaxations were attenuated in arteries from DOCA-salt rats. Genistein affected the contraction to phorbol 12, 13-dibutyrate (PDBu) neither in DOCA-salt nor in control arteries. These observations suggest that tyrosine kinase is involved in 5-HT-induced vascular contraction, of which role is reduced in DOCA-salt hypertension.

• The Journal of the Acoustical Society of Korea
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• 제14권2E호
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• pp.37-42
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• 1995

경계조건에 맞는 일련의 연속된 좌표계를 parabolic equation method에 적용한 polar parabolic equation method (Polar PE)는 하나의 곡면이나 언덕이 존재하는 경우 대기에서 음의 전파를 설명하는데 알맞은 수치 이론임이 입증되었다. 본 논문에서는 locally reacting 해저면과 pressure release 해수면의 경계조건을 사용하여 Polar PE 를 수중에서 해저구릉이 존재할 경우에 음의 전파를 설명하는데 적용하였다. 450m 높이의 해저구릉이 존재할 경우, 음의 전파에 관하여 계산하고 그 결과를 살펴보았다. Polar PE 를 수중에 해저구릉이 있는 경우 음의 전파를 계산하는데 적용가능성을 논의하였다.

• 태양에너지
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• 제15권3호
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• pp.91-103
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• 1995

튜브 내의 입구영역에서 대류와 비회복사(mon-gray radiation)가 동시에 일어날 때의 열전달 특성을 수치해석적으로 연구하였다. 작동유체는 이산화탄소, 수증기, 질소의 혼합가스라 하였고, 유동은 속도장과 온도장이 동시에 발달하는 층류 유동으로 가정하였다. 복사전달방정식을 풀기 편하게 하기 위해 P-1 근사법이 사용되었고 혼합가스의 비회흡수계수(non-gray sbsorption coefficient)는 지수광폭밴드모형(exponential wide band model)을 이용해서 구하였다. 열전달 특성에 대한 온도조건의 영향을 조사하기 위해 튜브의 축방향에 대한 평균온도와 뉴셀트수(Nusselt number)의 변화를 몇 가지 다른 온도조건에 대해 나타내었다. 속도장과 온도장이 동시에 발달하는 경우의 뉴셀트수를 속도장은 완전히 발달되어 있고 온도장만 발달하는 경우의 뉴셀트 수와 비교하였다. 또한, 가스의 성분조성이 대류와 비회복사 뉴셀트수에 미치는 영향을 조사하였다.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제5권4호
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• pp.316-321
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• 2005

We designed and implemented fish robots for various purposes such as autonomous navigation, maneuverability control, posture balancing and improvement of quick turns in a tank of 120 X 120 X 180cm size. Typically, fish robots have 30-50 X 15-25 X 10-20cm dimensions; length, width and height, respectively. It is essential to have the ability of quick and smooth turning to avoid collision with obstacles or walls of the water pool at a close distance. Infrared distance sensors are used to detect obstacles, magneto-resistive sensors are used to read direction information, and a two-axis accelerometer is mounted to compensate output of direction sensors. Because of the swing action of its head due to the tail fin movement, the outputs of an infrared distance sensor contain a huge amount of noise around true distances. With the information from accelerometers and e-compass, much improved distance data can be obtained by fuzzy logic based estimation. Successful swimming and smooth turns without collision demonstrated the effectiveness of the distance estimation.

• 대한한의학방제학회지
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• 제26권3호
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• pp.183-193
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• 2018

Objectives : In Traditional Korean Medicine, Epimedium koreanum Nakai has diverse pharmacological activities to treat impotence, forgetfulness, cataract and exophthalmos. Present study investigated anti-fibrogenic effects of E. koreanum water extract (EKE) in hepatic stellate cells (HSCs). Methods : To study anti-fibrogenic effects of EKE, LX-2 cells, a human immortalized HSCs, were pre-treated with $3-300{\mu}g/mL$ of EKE, and then subsequently exposed to 5 ng/mL of transforming growth $factor-{\beta}1$ ($TGF-{\beta}1$). Expression level of ${\alpha}-smooth$ muscle actin was determined by immunoblot analysis. Phosphorylation of Smad, transactivation of Smad, and expression of plasminogen activator inhibitor-1 (PAI-1) were monitored to investigate the effect of EKE on $TGF-{\beta}1-mediated$ signaling pathway. Results : Up to $100{\mu}g/mL$, EKE did not show any cytotoxicity on LX-2 cells. Pre-treatment of EKE ($100{\mu}g/mL$) significantly inhibited ${\alpha}-smooth$ muscle actin expression induced by $TGF-{\beta}1$. In addition, EKE significantly decreased Smad2 and Smad3 phosphorylations, Smad binding element-driven luciferase activity and PAI-1 expression by $TGF-{\beta}1$. Of three flavonoid compounds found in EKE, only quercertin ($30{\mu}M$) attenuated $TGF-{\beta}1-mediated$ PAI-1 expression. Conclusion : These results suggest that EKE has an ability to suppress fibrogenic process in HSCs via inhibition of $TGF-{\beta}1/Smad$ signaling pathway.

• 한국수자원학회논문집
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• 제33권6호
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• pp.815-825
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• 2000

Einstein(1942)의 부유사량 산정식 유도과정에 있어 몇 가지 문제점들을 개선하였다. 수류조건을 판별하여 완난류 조건에서 유속의 영점높이를 산정하는 방법을 제시하고 부유사량 산정식을 일반화할 수 있는 무차원수를 도입하였다. 또한, 기준점 농도 산정의 정확성을 개선하기 위하여 최근에 개발된 소류사량 산정식으로부터 관련치를 추정하였으며, 수치적으로 또는 도표를 이용하여 해를 구해야 하는 수심적분치의 근사식을 개발하였다. Einstein의 기존 부유사량 산정식과 개선된 부유사량 산정식의 정확도를 검토하여 Brownlie(1981)가 수집한 자료에 대한 산정결과를 제시하였다.

• 대한한방내과학회지
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• 제26권3호
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• pp.575-586
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• 2005

FC(free choresterol) plays an important role in normal and pathophysiological cells including that of messenger molecule or dilator of blood vessels in such illnesses as artheriosclerosis, hypertension and myocardial infarction. Smooth muscle and endothelial cell functions in the arteria wall are unified by complex intercellular signalling processes. In arteria comprised of one layer of smooth muscle cells surrounding the endothelium, the close apposition of the two cell types enables a signal derived from one cell to rapidly diffuse to neighboring cells. Experimentation was conducted to investigate the potential contribution of Sohaphyangwon(SHHW) on levels of FC generated by goaded microphages, and mechanisms of protection against ACAT inhibitor. It was found that J774 macrophages, which normally do not express FC were expressed by oxLDL and ACAT inhibitor. SHHW protected cells were found to be resistant to oxLDL and delayed death following the FC. Inhibition of FC formation abolished the protective effect against ACAT inhibitor exposure. Cadiovascular diseases include abnormalities of blood vessels dysfunction of the renin-angiotension system. What relation herbal medicine may have with vessel endothelium necrosis was here studied. In Oriental Medicine, SHHW water extract used for diseases in relation to cardiovascular systems. The resistence to cardiovascular disease of ACAT inhibitor induced J774 macrophage cells were studied through analysis of cell morphological patterns and immunochemistry of SHHW. The results of this study suggest that SHHW has protective effects on the cardiovascular system, and that it is effective in both prevention and treatment of diseases of the cardiovascular system, particularity against necrosis of blood.

• 약학회지
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• 제44권6호
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• pp.511-520
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• 2000

Various bupivacaine-loaded microspheres were prepared from poly (d,l-lactide) (PLA) or poly (d,l-lactic-co-glycolide) (PLGA) by a solvent evaporation method for the sustained release of drug. PLA and PLGA microspheres were prepared by w/o/w and w/o/o multiple emulsion solvent evaporation, respectively. The effects of process conditions such as emulsification speed, emulsifier type, emulsifier concentration and internal/external phase ratio on the characteristics of microspheres were investigated. The prepared microspheres were characterized for their drug loading, size distribution, surface morphology and release kinetics. Drug loading efficiency was higher in the microspheres prepared by w/o/o multiple emulsion than that by w/o/w multiple emulsion method, because the solubility of bupivacaine HCI was decreased in oil phase compared with water phase. The prepared microspheres had an average diameter between 1 and $2\;{\mu}M$ in all conditions of two methods. In morphology studies the PLA microspheres showed an irregular shape and smooth surface, but PLGA microspheres had a spherical shape and smooth surface. The release pattern of the drug from microspheres was evaluated on the basis of the burst effect and the extent of the release after 24h. The in vitro release of bupivacaine HCl from microspheres showed a large initial burst release and $60{\sim}80%$ release within one day in all conditions of two methods. The extents of the burst release against PLA and PLGA microspheres were $30{\sim}50%$ and $50{\sim}80%$ within 20min, respectively. This burst release seems to be due to the smaller size of microspheres and the solubility of drug in water.

• 한국식품영양과학회지
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• 제35권10호
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• pp.1456-1460
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• 2006

변질된 팥앙금에서 분리한 균주는 광학 및 전자현미경을 통하여 관찰한 결과 그람양성 간균으로 포자를 형성하고 형성된 집락은 원형으로 점질성의 물질을 생산하는 mucoid type이었으며, 표면은 smooth 하였고 광택을 나타내었다. 미생물 동정 시스템($MicroLog^{TM}$ System, Release 4)인 VITEK 2 COMPACT을 이용하여 분리된 균주의 46개의 생화학적 분석을 비교한 결과 팥앙금의 부패 원인균은 Bacillus subtilus로 동정 (97.0%)되었으며, 보다 더 정확한 동정을 위하여 부패균의 세포벽 지방산 조성을 분석하여 Midi sherlock시스템의 databank와 비교 분석시 그 유사성이 0.724로 분석되었다. Bacillus subtilus의 포자의 D-value는 $115^{\circ}C$에서의 4.85분이 었고, $121^{\circ}C$에서는 0.69분, $125^{\circ}C$에서는 0.48분이었으며, Z-value는 $9.71^{\circ}C$이었다. $45^{\circ}C$에서 수분활성도에 따른 분리균의 생육 상태를 관찰한 결과 수분활성도 0.92이하에서는 균이 증식되지 않았고, 0.94에서는 증식되는 것으로 관찰되었다.