• Title/Summary/Keyword: Metal

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The Effect of Nitric Oxide Donor or Nitric Oxide Synthase Inhibitor on Oxidant Injury to Cultured Rat Lung Microvascular Endothelial Cells (산화질소 공여물과 산화질소 합성효소 길항제가 백서 폐미세혈관 내피세포 산화제 손상에 미치는 영향)

  • Chang, Joon;Michael, John R.;Kim, Se-Kyu;Kim, Sung-Kyu;Lee, Won-Young;Kang, Kyung-Ho;Yoo, Se-Hwa;Chae, Yang-Seok
    • Tuberculosis and Respiratory Diseases
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    • v.45 no.6
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    • pp.1265-1276
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    • 1998
  • Background : Nitric oxide(NO) is an endogenously produced free radical that plays an important role in regulating vascular tone, inhibition of platelet aggregation and white blood cell adhesion to endothelial cells, and host defense against infection. The highly reactive nature of NO with oxygen radicals suggests that it may either promote or reduce oxidant-induced cell injury in several biological pathways. Oxidant injury and interactions between pulmonary vascular endothelium and leukocytes are important in the pathogenesis of acute lung injury, including acute respiratory distress syndrome(ARDS). In ARDS, therapeutic administration of NO is a clinical condition providing exogenous NO in oxidant-induced endothelial injury. The role of exogenous NO from NO donor or the suppression of endogenous NO production was evaluated in oxidant-induced endothelial injury. Method : The oxidant injury in cultured rat lung microvascular endothelial cells(RLMVC) was induced by hydrogen peroxide generated from glucose oxidase(GO). Cell injury was evaluated by $^{51}$chromium($^{51}Cr$) release technique. NO donor, such as S-nitroso-N-acetylpenicillamine(SNAP) or sodium nitroprusside(SNP), was added to the endothelial cells as a source of exogenous NO. Endogenous production of NO was suppressed with N-monomethyl-L-arginine(L-NMMA) which is an NO synthase inhibitor. L-NMMA was also used in increased endogenous NO production induced by combined stimulation with interferon-$\gamma$(INF-$\gamma$), tumor necrosis factor-$\alpha$(TNF-$\alpha$), and lipopolysaccharide(LPS). NO generation from NO donor or from the endothelial cells was evaluated by measuring nitrite concentration. Result : $^{51}Cr$ release was $8.7{\pm}0.5%$ in GO 5 mU/ml, $14.4{\pm}2.9%$ in GO 10 mU/ml, $32.3{\pm}2.9%$ in GO 15 mU/ml, $55.5{\pm}0.3%$ in GO 20 mU/ml and $67.8{\pm}0.9%$ in GO 30 mU/ml ; it was significantly increased in GO 15 mU/ml or higher concentrations when compared with $9.6{\pm}0.7%$ in control(p < 0.05; n=6). L-NMMA(0.5 mM) did not affect the $^{51}Cr$ release by GO. Nitrite concentration was increased to $3.9{\pm}0.3\;{\mu}M$ in culture media of RLMVC treated with INF-$\gamma$ (500 U/ml), TNF-$\alpha$(150 U/ml) and LPS($1\;{\mu}g/ml$) for 24 hours ; it was significantly suppressed by the addition of L-NMMA. The presence of L-NMMA did not affect $^{51}Cr$ release induced by GO in RLMVC pretreated with INF-$\gamma$, TNF-$\alpha$ and LPS. The increase of $^{51}Cr$ release with GO(20 mU/ml) was prevented completely by adding 100 ${\mu}M$ SNAP. But the add of SNP, potassium ferrocyanate or potassium ferricyanate did not protect the oxidant injury. Nitrite accumulation was $23{\pm}1.0\;{\mu}M$ from 100 ${\mu}M$ SNAP at 4 hours in phenol red free Hanks' balanced salt solution. But nitrite was not detectable from SNP upto 1 mM The presence of SNAP did not affect the time dependent generation of hydrogen peroxide by GO in phenol red free Hanks' balanced salt solution. Conclusion : Hydrogen peroxide generated by GO causes oxidant injury in RLMVC. Exogenous NO from NO donor prevents oxidant injury, and the protective effect may be related to the ability to release NO. These results suggest that the exogenous NO may be protective on oxidant injury to the endothelium.

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Physico-Chemical Properties of Aggregate By-Products as Artificial Soil Materials (골재 부산물의 용토재 활용을 위한 특성 분석)

  • Yang, Su-Chan;Jung, Yeong-Sang;Kim, Dong-Wook;Shim, Gyu-Seop
    • Korean Journal of Soil Science and Fertilizer
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    • v.40 no.5
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    • pp.418-428
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    • 2007
  • Physical and chemical properties of the aggregate by-products including sludge and crushed dust samples collected from the 21 private companies throughout the country were analyzed to evaluate possible usage of the by-products as artificial soil materials for plantation. The pH of the materials ranged from 8.0 to 11.0. The organic matter content was $2.85g\;kg^{-1}$, and the total nitrogen content and available phosphate content were low as 0.7 percents and $12.98mg\;kg^{-1}$, respectively. Exchangeable $Ca^{2+}$, $Mg^{2+}$, $K^+$, and $Na^+$ were 2.29, 0.47, 0.02 and $0.05cmol\;kg^{-1}$, respectively. Heavy metal contents were lower than the limits regulated by environmental law of Korea. Textural analysis showed that most of the materials were silt loam with low water holding capacity ranged from 0.67 to 7.41 percents, and with low hydraulic conductivity ranged from 0.4 to $2.8m\;s^{-1}$. Mineralogical analysis showed that the aggregate by product materials were mostly composed of silicate, alumina and ferric oxides except calcium oxide dominant materials derived from limestones. The primary minerals were quartz, feldspars and dolomites derived from granite and granitic gneiss materials. Some samples derived from limestone material showed calcite and graphite together with the above minerals. According to the result, it can be concluded that the materials could be used as the artificial soil material for plantation after proper improvement of the physico-chemical properties and fertility.

Sovereignty and Wine Vessels: The Feast Culture of the Goryeo Court and the Symbolic Meaning of Celadon Wine Vessels (고려 왕실의 연례 문화와 청자 주기(酒器)의 상징적 의미: 왕권과 주기(酒器))

  • Kim Yun-jeong
    • MISULJARYO - National Museum of Korea Art Journal
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    • v.104
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    • pp.40-69
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    • 2023
  • This paper examines the relationship between celadon wine vessels and royal banquets by focusing on their unique forms. It explores the symbolism in their forms and designs and the changes that took place in the composition of these vessels. By examining the royal annals in Goryeosa (The History of the Goryeo Dynasty), the relation of celadon wine vessels and royal banquets is examined in terms of the number of banquets held in the respective reigns of the Goryeo kings, the number of banquets held by type, and the purpose of holding them. A royal banquet was a means of strengthening the royal authority by reinforcing the hierarchy and building bonds between the king and his vassals. It was also an act of ruling that demonstrated the king's authority and power through praise of his achievements and virtues. Royal banquets were held most often during the reigns of King Yejong (r. 1105-1122), King Uijong (r. 1146-1170), King Chungnyeol (r. 1274-1308), and King Gongmin (r. 1351-1374). Particular attention is paid here to the changes in the types and forms of celadon wine vessels that occurred starting in the reigns of King Yejong and King Chungnyeol, which is also the period in which the number of royal banquets increased and royal banquet culture evolved. The king and his subjects prayed for the king's longevity at royal banquets and celebrated peaceful reigns by drinking and performing various related acts. Thus, the visual symbolism of vessels for holding, pouring, or receiving alcohol were emphasized. Since the manner of drinking at a banquet was exchanges of pouring and receiving alcohol between the king and his subjects, the design of the ewers and cups had a significant visual impact on attendees. It can be seen, therefore, that decorating wine vessels with Daoist motifs such as the immortals, luan (a mythological bird), turtle dragons, fish dragons, and gourd bottles or with Confucian designs like hibiscus roots was intended as a visual manifestation of the purpose of royal banquets, which was to celebrate the king and to pray for both loyalty and immortality. In particular, the Peach Offering Dance (獻仙桃) and Music for Returning to the Royal Palace (還宮樂), which correspond to the form and design of celadon wine vessels, was examined. The lyrics of the banquet music embodied wishes for the king's longevity, immortality, and eternal youth as well as for the prosperity of the royal court and a peaceful reign. These words are reflected in wine vessels such as the Celadon Taoist Figure-shaped Pitcher housed in the National Museum of Korea and the Bird Shaped Ewer with Daoist Priest in the Art Institute of Chicago. It is important to note that only Goryeo celadon wine vessels reflect this facet of royal banquet culture in their shape and design. The composition of wine vessel sets changed depending on the theme of the banquet and the types of liquor. After Goryeo Korea was incorporated into the Mongol Empire, new alcoholic beverages were introduced, resulting in changes in banquet culture such as the uses and composition of wine vessel sets. From the reign of King Chungnyeol (r. 1274-1308), which was under the authority of the Yuan imperial court, royal banquets began to be co-hosted by kings and princesses, Mongolian-style banquets like boerzhayan (孛兒扎宴) were held, and attendees donned the tall headdress called gugu worn by Mongol women. During the reign of King Chungnyeol, the banquet culture changed 132 banquets were held. This implies that the court tried to strengthen its authority by royal marriage with the Yuan court, which augmented the number of banquets. At these banquets, new alcoholic drinks were introduced such as grape wine, dongnak (湩酪), and distilled liquor. New wine vessels included stem cups, pear-shaped bottles (yuhuchunping), yi (匜), and cups with a dragon head. The new celadon wine vessels were all modeled after metal wares that were used in the Yuan court or in the Khanates. The changes in the celadon wine vessels of the late Goryeo era were examined here in a more specific manner than in previous studies by expanding the samples for the study to the Eurasian khanates. With the influx of new types of wine vessels, it was natural for the sets and uses of Goryeo celadon wine vessels to change in response. The new styles of celadon wine vessels linked the Goryeo court with the distant Khanates of the Mongol Empire. This paper is the beginning of a new study that examines the uses of Goryeo celadon by illuminating the relations between royal banquets and these unique celadon wine vessels that are stylistically different from everyday vessels. It is to be hoped that more studies will be conducted from diverse perspectives exploring both the usage of Goryeo celadon vessels and their users.

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