• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.169.2-169.2
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• 2010

Recently, the massive offshore bridges in a ship passage have been constructed on the sea. Therefore, the ship impact protection for the bridge-piers are installed to consider the possibility of vessel collision danger. Due to the ship impact protection, the flow-field characteristics are changed in comparison with the condition without the ship impact protection. Especially, the fluid velocity between the pier and the ship impact protection is possible to increase due to the contraction of the cross sectional area of flow. In this study, the tidal energy magnitude around the ship impact protection of Incheon bridge is assessed by simulating the flow-field by using FLOW-3D software.

• 생약학회지
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• 제19권2호
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• pp.102-110
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• 1988

The pharmacological activities on water extracts of Cortex, Ramulus and Folium from the Eucommia ulmoides Oliver were studied, and the following results were observed. The vasodilative action on the rabbit ear blood vessel was recognized in the Cortex, Ramulus and Folium. The spontaneous motility and the contraction induced by Ach., $BaCl_2$ and histamine in the isolated ileum of mice were suppressed and inhibited in the Ramulus only. On the contrary, the analgesic and anti-inflammatory activities were noted in the Cortex and Folium. Furthermore, the hypotensive effect was recognized in the Folium. The diuretic, bile secretory and anti-fatigue effects were shown in the Cortex and Folium.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2001년도 추계학술대회 및 정기총회
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• pp.98-98
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• 2001

It has been suggested that hyperuricemia is related to the development of essential hypertension. Hypertensive patients with hyperuricemia has decreased glomerular filtration activity as compared to normotensive patients with hyperuricemia. These studies indicates uric acid concentrations in blood is associated with hypertension, Probenecid is an uricosuric agent which decreases uric acid reabsorption at the proximal tubule. Recently, we have shown that probenecid exerts anti-hypertensive action in Spontaneously Hypertensive Rats. Considering these results, I have designed a series of experiments to explore potential mechanism of antihypertensive action, of probenecid. In isolated rat thoracic aorta. probenecid significantly prevented phenylephrine-induced contraction of the blood vessel. When endothelium removed blood vessels were used, probenecid produced same effect as the intact blood vessels, indicating that probenecid directly act through the ${\alpha}$ -adrenergic receptor in vascular smooth muscles rather than through endothelium. These results suggest that one of the mechanism of antihypertensive effects of probenecid is due to the direct inhibition of ${\alpha}$ -adrenergic receptor in blood vessels.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.542-546
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• 2008

In this study, we developed a whole cardiovascular system model combined with a Laplace heart based on the numerical cardiac cell model and a detailed arterial network structure. The present model incorporates the Laplace heart model and pulmonary model using the lumped parameter model with the distributed arterial system model. The Laplace heart plays a role of the pump consisted of the atrium and ventricle. We applied a cellular contraction model modulated by calcium concentration and action potential in the single cell. The numerical arterial model is based upon a numerical solution of the one-dimensional momentum equations and continuity equation of flow and vessel wall motion in a geometrically accurate branching network of the arterial system including energy losses at bifurcations. For validation of the present method, the computed pressure waves are compared with the existing experimental observations. Using the cell-system-arterial network combined model, the pathophysiological events from cells to arterial network are delineated.

• The Korean Journal of Physiology and Pharmacology
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• 제6권1호
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• pp.33-39
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• 2002

It has been suggested that $Ca^{2+}$ sensitization mechanisms might contribute to myogenic tone, however, specific mechanisms have not yet been fully identified. Therefore, we investigated the role of protein kinase C (PKC)- or RhoA-induced $Ca^{2+}$ sensitization in myogenic tone of the rabbit basilar vessel. Myogenic tone was developed by stretch of rabbit basilar artery. Fura-2 $Ca^{2+}$ signals, contractile responses, PKC immunoblots, translocation of PKC and RhoA, and phosphorylation of myosin light chains were measured. Stretch of the resting vessel evoked a myogenic contraction and an increase in the intracellular $Ca^{2+}$ concentration $([Ca^{2+}]_i)$ only in the presence of extracellular $Ca^{2+}$. Stretch evoked greater contraction than high $K^+$ at a given $[Ca^{2+}]_i.$ The stretch-induced increase in $[Ca^{2+}]_i$ and contractile force were inhibited by treatment of the tissue with nifedipine, a blocker of voltage-dependent $Ca^{2+}$ channel, but not with gadolinium, a blocker of stretch-activated cation channels. The PKC inhibitors, H-7 and calphostin C, and a RhoA-activated protein kinase (ROK) inhibitor, Y-27632, inhibited the stretch-induced myogenic tone without changing $[Ca^{2+}]_i.$ Immunoblotting using isoform-specific antibodies showed the presence of $PKC_{\alpha}$ and $PKC_{\varepsilon}$ in the rabbit basilar artery. $PKC_{\alpha},$ but not $PKC_{\varepsilon},$ and RhoA were translocated from the cytosol to the cell membrane by stretch. Phosphorylation of the myosin light chains was increased by stretch and the increased phosphorylation was blocked by treatment of the tissue with H-7 and Y-27632, respectively. Our results are consistent with important roles for PKC and RhoA in the generation of myogenic tone. Furthermore, enhanced phosphorylation of the myosin light chains by activation of $PKC_{\alpha}$ and/or RhoA may be key mechanisms for the $Ca^{2+}$ sensitization associated with myogenic tone in basilar vessels.

• 동의생리병리학회지
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• 제16권5호
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• pp.938-942
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• 2002

We have examined the relaxational response to the water extract of Rheum palmatum L.(ERP) and water extrc alcohol processed Rheum palmatum L.(ARP) in isolated thoracic aorta from sprague dawley (SD) rat. Rat thoracic aort investigated in vessel segments suspended for isometric tension recording by polygraph. Responses to ERP and ARP investigated in vessels precontracted with 5-hydroxytryptamine(5-HT). We found that the thoracic aorta segments respo to ERP and ARP with a dose-dependent vasorelaxation. We found that ; The thoracic aorta segments responded to I and ARP with a dose-dependent vasodilation. The 5-HT induced contraction at 10/sup -4/M were inhibited by 71.7% and a: after addition of the 0.01 g/mL water extract of ERP and ARP. The 5-HT induced contraction at 10/sup -4/M were inhibite 100% after 10/sup -3/M emodin. The concentration of emodin was 0.027% and 0.098% in ERP and ARP. In condusion, ERP ARP induced relaxation in the isolated rat thoracic aorta were composed of dose-dependent relaxation. and it has pi vasodilation.

• Journal of Chest Surgery
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• 제46권6호
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• pp.413-425
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• 2013

Background: Graft vessel preservation solution in coronary artery bypass surgery is used to maintain the graft conduit in optimal condition during the perioperative period. Nafamostat mesilate (NM) has anticoagulation and anti-inflammatory properties. Therefore, we investigated NM as a conduit preservative agent and compared it to papaverine. Methods: Sprague-Dawley (SD) rat thoracic aortas were examined for their contraction-relaxation ability using phenylephrine (PE) and acetylcholine (ACh) following preincubation with papaverine and NM in standard classical organ baths. Human umbilical vein endothelial cells (HUVECs) were cultured to check for the endothelial cell viability. Histopathological examination and terminal deoxynucleotidyl transferase dUTP nick end labeling assay were performed on the thoracic aortas of SD rats. Results: The anti-contraction effects of papaverine were superior to those of NM at PE (p<0.05). The relaxation effect of NM on ACh-induced vasodilatation was not statistically different from that of papaverine. Viability assays using HUVECs showed endothelial cell survival rates of >90% in various concentrations of both NM and papaverine. A histopathological study showed a protective effect against necrosis and apoptosis (p<0.05) in the NM group. Conclusion: NM exhibited good vascular relaxation and a reasonable anti-vasocontraction effect with a better cell protecting effect than papaverine; therefore, we concluded that NM is a good potential conduit preserving agent.

• Journal of Chest Surgery
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• 제28권8호
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• pp.742-746
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• 1995

The present study was aimed at investigating possible transmitter mechanisms in the endothelial cell layer in regulating the tone of the vascular smooth muscle. The thoracic aorta was isolated from the anesthetized male white rabbits and its helical strips were prepared. Electrical field stimulation was delivered to platinum wire electrodes positioned parallel to the vessel segment preconstricted with phenylephrine [3.5x10-6 mol/L at a distance of 1.5-2.0 mm. The electrical stimulation [70 V, 5 msec, 0.5-200 Hz caused either relaxation only [34% or a biphasic response [prolonged relaxation following a weak and transient contraction, 66% . The relaxation response was frequency- dependent, and at 200 Hz a complete relaxation was noted. Mechanical rubbing of the endothelial layer abolished or greatly attenuated the relaxation. The relaxation was also markedly attenuated in the presence of NG-nitro- L-arginine methyl ester [10-3mol/L or procaine hydrochloride [3.5x10-4mol/L . Tetrodotoxin,guanethidine, atropine or indomethacin failed to block or enhance the relaxation response to electrical field stimulation. It is concluded that the vascular endothelium in the aorta contains diffusible substances that regulates the function of the smooth muscle layer, in which relaxation is more prominent than contraction. Their release by the electrical stimualtion in vitro may not involve classic neuronal transmitter release mechanisms or metabolism of arachidonic acids by cyclooxygenase. The release of the relaxing agents may require an increase in cytosolic calcium level. The chemical nature of the relaxant may be, to a large extent, nitric oxide.

• 박물관보존과학
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• 제2권
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• pp.27-34
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• 2000

다호리 출토 목재의 수종은 전체 24점 모두 활엽수 8종류로 상수리나무류(37.7%), 밤나무(8.3%), 벚나무속(8.3%), 감탕나무속(4.1%), 오리나무류(25%), 산복사류(4.1%), 느티나무(4.1%), 물푸레나무속(8.3%)으로 식별되었다. 출토목재의 물리적 특성은 현생재에 비해 높은 함수율과 수축율 그리고 현저한 밀도 감소를 나타내었다. 분해상태는 편광현미경 관찰결과 현생재에 비해 모든 출토목재의 도관을 제외한 나머지 부분에서 복굴절현상 감소가 뚜렷하게 나타났으며 주사전자현미경 관찰에서는 목섬유의 2차 세포벽을 포함한 구성조직이 현저하게 분해되었다. 분해가 많이 된 목재는 개방성이 확대되어 약제의 침투·확산이 용이하므로 처리기간이 짧고, PEG#4000(MW:3,350)을 적용한 고분자약제 함침처리가 유리하며 고농도의 함침 처리가 요구된다.

• 대한한방내과학회지
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• 제1권1호
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• pp.25-34
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• 1976

The extract of commercial mistletoe caused transient contraction of mouse ileum in vitro at the level of $7{\times}10^{-4}g/ml$ and augmented significantly its peristalsis. When the ileum was pre-treated With $10^{-6}g/ml$ of adrenaline the administration of the extract at a level of $10^{-4}g/ml$ blocked the contraction. The increase inperistalsis and intention was also observed in rabbit ileum in vitro with the administration of the extract at a level of $10^{-1}g/ml$ but these phenomenon were inhibited by the adrenaline treatment at a level of $10^{-6}g/ml.$ When the extract was applied to spirally cut strips of thoracic aorta at the level of $10^{-3}g/ml$ the contractile action of adrenaline was significantly inhibited. When the extract was infused to auricular blood vessel of rabbit at the rate of $10^{-4}g/ml,\;10^{-3}g/ml,\;10^{-2}g/ml$ and $10^{-1}g/ml$ increases in number of drops by 70%, 77%, 93% and 100% were observed if the maximum number of drops caused by $10^{-1}g/ml$ is considered to be 100%. The duration of prolongation was proportionate to the increase in concentration of the extract. Hypotensive action of the extract and its duration were proportionately increased as the quantity of the extract increased. The increase in number and depth of respiration observed during the hypotensive status was brought to the normal when the tension became normal. In view of these observations it is concluded that the extract of commercial mistletoe has a contractile action of acetylcholine effect in the ileum of mouse and rabbit, loosens both aorta and smooth muscle and promotes peripheral circulation. As for the hypotensive action it is concluded that the action is brought about by the decrease in peripheral circulatory resistance due to the antagonism between acetylcholine and adrenaline.