• Korean Journal of Environmental Agriculture
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• v.16 no.4
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• pp.399-403
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• 1997

Changes of nutrient material and natural supplies by sediment of irrigation water into 1.0ha of paddy field during the rice cultivation were investigated. TSS of the sediment contained irrigation water ranged 52.9${\sim}$125.6mg/L and content of organic matter showed 1.89${\sim}$2.33%. Content of T-N, $NH_4-N$ and $NO_3-N$ were 623.5${\sim}$1775.2, 22.9${\sim}$75.8 and 10.2${\sim}$72.1mg/kg respectively. Content of T-P and ortho-P were 186.7${\sim}$375.7 and 12.4${\sim}$38.9mg/kg respectively. The content of exchangeable canons, $Ca^{++},\;Mg^{++}\;Na^+\;and\;K^+$ were 435.3${\sim}$737.5, 127.3${\sim}$204.2, 36.6${\sim}$94.9 and 105.6${\sim}$232.9mg/kg respectively. Total content of heavy metals were 13.4 of Pb, 0.6 of Cd, 8.2 of Ni, 12.1 of Cu, 29.8 of Zn and 19.7mg/kg of Cr. During the period of rice cultivation, when supplied 4,250m^3 of an irrigation water into 1.0ha of paddy field, natural supplied 346.01kg of sediment, 7.11kg of organic matter, 0.50kg of T-N, 0.02㎏ of NH_4-N, 0.01kg of NO_3-N, 0.08kg of T-P and 0.01㎏ of Ortho-P. Also exchangeable $Ca^{++},\;Mg^{++}\;Na^+\;and\;K^+$ were supplied 0.21, 0.06, 0.02 and 0.06kg respectively. Loaded of the total heavy metal showed natural background level.

• Journal of Chest Surgery
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• v.31 no.9
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• pp.884-892
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• 1998

Background: The gastroepiploic artery is not only an alternative graft but also may be considered an important primary graft for coronary revascularization. However, the long-term patency of the gastroepiploic arterial graft is yet to be determined and the incidence of perioperative spasm and long-term patency of a coronary graft may be affected by the properties of the graft response to certain vasoactive substances. The reactivity of the gastroepiploic artery to vasoactive substances has not been studied extensively and the results of the studies are contradictory. Material and Method: This study was designed to test the reactivity of human gastroepiploic artery to four constrictors and four relaxants. The middle sections of the human gastroepiploic arteries were collected from the patients undergoing gastrectomy and the arterial rings with intact endothelium were suspended in organ baths for isometric tension recording. Result: Epinephrine, norepinephrine, and potassium chloride induced the maximum constriction to higher forces (7.0$\pm$1.1g, 6.6$\pm$0.9g, and 6.5$\pm$1.1g) than 5-hydroxytryptamine did (3.8$\pm$1.7g, p<0.05). Nitroprusside and histamine induced almost full relaxation in the gastroepiploic arteries preconstricted with norepinephrine. There was no significant difference between two relaxants regarding maximum relaxation force. Acetylcholine induced the maximum relaxation to weaker force when compared with nitroprusside and histamine (p<0.05), and isoproterenol was the weakest of the relaxants (p<0.05 compared with acetylcholine). Conclusion: The gastroepiploic artery has a strong capacity of endothelium-dependent relaxation which could have an important influence on long-term patency. The gastroepiploic artery exhibits a potent contractility to catecholamines and the enhanced contractility may facilitate vasospasm in the presence of high circulating levels of catecholamines. Nitroprusside, a potent relaxant in gastroepiploic artery, might be beneficial for the treatment of gastroepiploic arterial graft spasm. The gastroepiploic arterial graft with intact endothelium may respond weakly to beta-adrenoceptor agonist and 5-hydroxytryptamine.