• Title/Summary/Keyword: Kwon Seop

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An Experimental Study on Pearl Oyster (Pinctada fucata) Culture (인공진주 양식에 관한 시험연구)

  • CHO Chang-Hwan;KWON Woo-Seop;KIM Moo-Sang;KIM Nam-Gil;LIM Dong-Taik
    • Journal of Aquaculture
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    • v.1 no.1
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    • pp.85-102
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    • 1988
  • An experimental study on seedling production and wintering to develop pearl oyster, Pinctada fucata culture in Korea was carried out. from December 1986 to November 1988 in waters of Kori and of Seogwipo as wintering and of Eogu as culturing grounds. All pearl oysters as the sample were imported from Japan. The highest water temperature at Eogu was $23.6^{\circ}C$ in August and the lowest at Kori and Seogwipo were $13.2^{\circ}C$ and $14.0^{\circ}C$c in February, respectively, Phytoplankton was relatively plentiful but mortality of pearl oysters was $20.5\%$, which was twice at Seogwipo, due to high amount of suspended muds. It shows that Seogwipo is better wintering ground even though the amount of phytoplankton is lower than Kori. Average rates of pearl production after 6-months and 15-months period were $58.2\%$ and $48.3\%$ respecitively. Thickness of pearl layer and coating rate were also satisfactory. More than half of the pearls produced was so-called the pink-pearl, the best colour. About $10\%$ of them was the best quality. There were three peaks of D-shape larvae from July to September and it took about one month for D-shape larvae to become seed-shells. Settling was satisfactory and most of them settled at 1$\~$3 m layer and the best was 2 m-layer. Success of settling was supposed due to high water temperature and low precipitation than the normal year.

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A Clinical and Radiologic Study of Acute Focal Bacterial Nephritis in Children (소아에서의 급성 국소성 세균성 신장염의 임상 및 방사선학적 고찰)

  • Song, Kum Ho;Huh, Kwon Hoe;Cho, Ok Yeon;Sim, Jae Hoon;Cho, Do Jun;Kim, Dug Ha;Min, Ki Sik;Yoo, Ki Yang;Lee, Kwan Seop
    • Clinical and Experimental Pediatrics
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    • v.46 no.4
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    • pp.351-357
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    • 2003
  • Purpose : To raise awareness of the clinical importance of, and the need for proper management of acute focal bacterial nephritis(AFBN), we analyzed 22 AFBN patients and 22 other upper urinary tract infection patients by use of comparative studies. Methods : From January 2000 to May 2002, 22 AFBN patients aged from 1 month to 12 months were selected. As a control group, 22 UTI patients with no radiologic abnormalities were selected and matched by age and sex. Results : The incidence of AFBN was more common in boys than in girls. Since both groups had similar symptoms, it was difficult to diagnose AFBN by clinical presentations alone. ESR and CRP were significantly higher in AFBN patients. The most common causative organism was E. coli in both groups. On the sonographic findings, the most lesions were seen on the upper lobe of the kidney; more frequently, on left kidney. The lesions showed globular or wedge-shaped increased echogenecity. $^{99m}Tc-DMSA$ scan showed the complete coincidence of the location, size and shape in all cases compared to the findings of renal sonography. Conclusion : The roles of renal sonography and DMSA scan were very important, and ultrasonography was an excellent initial tool in diagnosing AFBN. Since the degree of infection in AFBN is more severe than other urinary tract infections and evollution into a renal abscess is possible, early diagnosis and appropriate antibiotics therapy is essential.

Follow-up Study of Children with Anthracycline Cardiotoxicity (소아 Anthracycline 심독성의 추적 관찰)

  • Kwon, Hyok Joo;Song, Young Hwan;Kang, Soo Jung;Kang, Hyoung Jin;Choi, Hyoung Soo;Bae, Eun Jung;Shin, Hee Young;Noh, Chung Il;Yun, Yong Soo;Ahn, Hyo Seop
    • Clinical and Experimental Pediatrics
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    • v.46 no.3
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    • pp.242-249
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    • 2003
  • Purpose : We studied the relationship between anthracycline cumulative dose and anthracycline cardiotoxicity in childhood cancer and followed up 40 children with anthracycline cardiotoxicity. Methods : A retrospective study was performed in 154 children who received anthracycline chemotherapy between January 1995 to December 2000. Cardiotoxicity was defined when the left ventricular fractional shortening(FS) was below 26%; it was divided into two groups, mild and severe cardiotoxicity, according to the FS. We followed up survivors with cardiotoxicity, and checked their present cardiac function by physical activity, echocardiography, electrocardiography(EKG) and chest X-ray. Results : Of the 154 children treated with anthracyclines, forty(26.0%) were diagnosed as cardiotoxicity. The incidence of cardiotoxicity increased in exponential fashion with increases in the cumulative dose of anthracyclines. There was minimal increase of incidence until a dose of $300mg/m^2$ after which the incidence increased rapidly. After mean $3.8{\pm}1.8year$ follow-up of 23 survivors with cardiotoxicity, FS increased significantly. EKG and chest X-rays were not helpful for the diagnosis of cardiotoxicity because of their low sensitivity and specificity. Conclusion : Although convenient, non-invasive and inexpensive, EKG and chest X-rays were not helpful for the follow-up of anthracycline cardiotoxicity. Almost all survivors with anthracycline cardiotoxicity have improved in both physical activity and echocardiographic findings after discontinuation of anthracyclines.

Hypoxia-dependent mitochondrial fission regulates endothelial progenitor cell migration, invasion, and tube formation

  • Kim, Da Yeon;Jung, Seok Yun;Kim, Yeon Ju;Kang, Songhwa;Park, Ji Hye;Ji, Seung Taek;Jang, Woong Bi;Lamichane, Shreekrishna;Lamichane, Babita Dahal;Chae, Young Chan;Lee, Dongjun;Chung, Joo Seop;Kwon, Sang-Mo
    • The Korean Journal of Physiology and Pharmacology
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    • v.22 no.2
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    • pp.203-213
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    • 2018
  • Tumor undergo uncontrolled, excessive proliferation leads to hypoxic microenvironment. To fulfill their demand for nutrient, and oxygen, tumor angiogenesis is required. Endothelial progenitor cells (EPCs) have been known to the main source of angiogenesis because of their potential to differentiation into endothelial cells. Therefore, understanding the mechanism of EPC-mediated angiogenesis in hypoxia is critical for development of cancer therapy. Recently, mitochondrial dynamics has emerged as a critical mechanism for cellular function and differentiation under hypoxic conditions. However, the role of mitochondrial dynamics in hypoxia-induced angiogenesis remains to be elucidated. In this study, we demonstrated that hypoxia-induced mitochondrial fission accelerates EPCs bioactivities. We first investigated the effect of hypoxia on EPC-mediated angiogenesis. Cell migration, invasion, and tube formation was significantly increased under hypoxic conditions; expression of EPC surface markers was unchanged. And mitochondrial fission was induced by hypoxia time-dependent manner. We found that hypoxia-induced mitochondrial fission was triggered by dynamin-related protein Drp1, specifically, phosphorylated DRP1 at Ser637, a suppression marker for mitochondrial fission, was impaired in hypoxia time-dependent manner. To confirm the role of DRP1 in EPC-mediated angiogenesis, we analyzed cell bioactivities using Mdivi-1, a selective DRP1 inhibitor, and DRP1 siRNA. DRP1 silencing or Mdivi-1 treatment dramatically reduced cell migration, invasion, and tube formation in EPCs, but the expression of EPC surface markers was unchanged. In conclusion, we uncovered a novel role of mitochondrial fission in hypoxia-induced angiogenesis. Therefore, we suggest that specific modulation of DRP1-mediated mitochondrial dynamics may be a potential therapeutic strategy in EPC-mediated tumor angiogenesis.

Study on the Community Structure of Benthic Macro-Invertebrates in Jangsu-cheon, an Urban Restoration Stream of Incheon City (인천시 도시복원하천 장수천의 저서성대형무척추동물의 군집구조에 관한 연구)

  • Song, Yeong-Ju;Ju, Yong-Don;Park, Bo-Sun;Kim, Jong-Myung;Kwon, Eun-Ho;Chae, Do-Young;Lee, Hee-Jo;Bae, Yang-Seop
    • Journal of Wetlands Research
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    • v.18 no.1
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    • pp.32-38
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    • 2016
  • The purpose of this study is to investigate the effects of the natural river conservation work and to find remedies for them, targeting Jangsu-cheon with high frequency of use by citizens among the rivers in Incheon Metroplitan City, Korea; for this, this study conducted investigations and analyses of Jangsu-cheon completed in December, 2008. As a result of investigating 3 spots for the water system of Jangsu-cheon over a total of 3 years (2009, 2010, 2014), it was found that benthic macro-invertebrates of a total of 3 phyla, 5 classes, 11 orders, 26 families, 56 species, and 980 specimens were distributed there. When they were analyzed by year, 18 families and 30 species in 2009, right after the natural river conservation work, and 22 families and 37 species in 2010, 2 years after the work, were found, with 7 species increasing in number; after that, as a result of the investigation in 2014, 22 families and 38 species were found, which tells the river has entered the stabilization stage since the recovery in 2010.Therefore, this study could identify: the water environment of the river was improved due to the natural river conservation work for Jangsu-cheon; in addition, Jangsu-cheon showed good ecological environment due to the continuous maintenance of the good wetlands in Incheon Grand Park in the upper area of the river; and the natural river conservation work of Jangsu-cheon created positive effects.

Changes in the Activities of Antioxidant Enzymes during Chilling Stress in Chilling-Tolerant and Chilling-Sensitive Cultivars of Cucurbita spp. (내저온성과 민감성 호박 품종의 저온 스트레스에 대한 항산화효소의 활성 차이)

  • Kang, Nam-Jun;Kwon, Joon-Kook;Cho, Yong-Seop;Choi, Young-Hah
    • Journal of Bio-Environment Control
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    • v.16 no.1
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    • pp.54-61
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    • 2007
  • To determine whether antioxidant enzyme systems are related to chilling tolerance, changes of antioxidant enzyme activities during the chilling stress were determined in the leaves of a chilling-tolerant cultivar (Cucurbita ficifolia, cv. Heukjong) and a chilling-sensitive cultivar (Cucurbita moschata, cv. Jaerae 13). Leaves of chilling-tolerant plant have two major isoforms, Fe-SOD and Mn-SOD, at the Rm values of 0.20 and 0.52, respectively. In leaves of chilling-sensitive plant, two major isozymes of SOD was observed, one isoform is Mn-SOD at the Rm value of 0.20, and the other isoform is Cu/zn-SOD at the nm value of 0.58. When plants were treated with chilling stress, Cu/zn-SOD at the Rm value of 0.58 was newly expressed at 10 days after chilling stress in the chilling-tolerant plants, and density of this band increased at five days after chilling stress in the chilling-sensitive plants. One APX isozyme band was observed in unstressed plants of both cultivars. Under the chilling stress one APX isozyme band was newly expressed at 10 days after chilling stress in the chilling-tolerant cultivar. Significant genotype differences were observed fnr POD isozyme banding patterns such as few main isozyme bands in chilling-tolerant plants, and one band in chilling-sensitive plants. Densities of three POD isozyme bands at the Rm of 0.36, 0.40 and 0.54 increased at 10 days after chilling stress in the chilling-tolerant plants, while two bands at the nm of 0.36 and 0.54 increased at 10 days and 20 days after chilling stress in the chilling-sensitive plants, respectively. Activities of SOD, APX and POD significantly increased during five days after chilling stress in both cultivars. In the chilling-tolerant cultivar, activities of these enzymes were higher in chilling-stressed plant than in unstressed plants. However, activities of these enzymes in the chilling-sensitive cultivar decreased rapidly after five days of chilling stress, and were lower in chilling stressed plants than in unstressed plants.

Development of a Testing Environment for Parallel Programs based on MSC Specifications (MSC 명세를 기반으로 한 병렬 프로그램 테스팅 환경의 개발)

  • Kim, Hyeon-Soo;Bae, Hyun-Seop;Chung, In-Sang;Kwon, Yong-Rae;Chung, Young-Sik;Lee, Byung-Sun;Lee, Dong-Gil
    • Journal of KIISE:Computing Practices and Letters
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    • v.6 no.2
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    • pp.135-149
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    • 2000
  • Most of prior works on testing parallel programs have concentrated on how to guarantee the reproducibility by employing event traces exercised during executions of a program. Consequently, little work has been done to generate test cases, especially, from specifications produced from software development process. In this research work, we devise the techniques for deriving test cases automatically from the specifications written in Message Sequence Charts(MSCs) which are widely used in telecommunication areas and develop the testing environment for performing module testing of parallel programs with derived test cases. For deriving test cases from MSCs, we have to uncover the causality relations among events embedded implicitly in MSCs. For this, we devise the methods for adapting vector time stamping to MSCs, Then, valid event sequences, satisfying the causality relations, are generated and these are used as test cases. The generated test cases, written in TTCN, are translated into CHILL source codes, which interact with a target module to be tested and test the validity of behaviors of the module. Since the testing method developed in this research work extracts test cases from the MSC specifications produced front telecommunications software development process, it is not necessary to describe auxiliary specifications for testing. In audition adapting vector time stamping generates automatically the event sequences, the generated event sequences that are ones for whole system can be used for individual testing purpose.

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Changes of Benthic Macroinvertebrate Communities after a Small Dam Removal from the Gyeongan Stream in Gyeonggi-do, Korea (경기도 경안천에서 소형 보(洑)의 철거 이후에 변화된 저서성 대형무척추동물 군집)

  • Kil, Hye-Kyung;Kim, Dong-Gun;Jung, Sang-Woo;Shin, Il-Kwon;Cho, Kang-Hyun;Woo, Hyo-Seop;Bae, Yeon-Jae
    • Korean Journal of Environmental Biology
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    • v.25 no.4
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    • pp.385-393
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    • 2007
  • Benthic macroinvertebrate communities were studied after a small dam removal from the mid-section of the Gyeongan stream in Gyeonggi-do, Korea. Quantitative sampling was conducted at immediately upstream (upper) and downstream (lower) sites from the dam as well as at the site where the dam was located (dam site: middle) using a Surber sampler (50$\times$50 cm, mesh 0.25 mm), four times (November 2004, May 2005, January 2006, and May 2006) after the dam removal. As a result, 46 species of benthic macroinvertebtates, belonged in 35 genera, 27 families, 11 orders, 5 classes, and 4 phyla, were sampled from the stream sites, but the number of species that occurred at each sampling trial was different (ranged 3$\sim$17 spp.) according to the seasons and sites. Approximately one year after the dam removal, the species number has in-creased and taxa composition has changed as the microhabitat became more heterogeneously due to a riffle formation in the upstream site. Chironomid larvae and tubificid worms, which are common in Korean urban streams, were the dominant species, while Hydropsyche kozhantschikovi was the 2nd dominant species at some sampling trials. In general, McNaughton's dominance indices decreased and Shannon species diversity indices increased approximately one year after the dam removal. Compositions of collector-filterers, clingers, and swimmers increased as hydropsychid caddisflies, heptageniid mayflies, and baetid mayflies increased, respectively, in the upstream site. The group pollution index and the ecological score using benthic macroinvertebrates both indicated that water environment has been improved in the upstream site after the dam removal.

Studies on the Development of Natural Preservatives from Natural Products (전통식품 및 천연물에서 천연보존료 개발에 관한 연구)

  • Kim, Hee-Yun;Lee, Young-Ja;Hong, Ki-Hyoung;Kwon, Yong-Kwan;Lee, Ju-Yeun;Kim, So-Hee;Ha, Sang-Chunl;Cho, Hong-Yon;Chang, Ih-Seop;Lee, Chul-Won;Kim, Kil-Saeng
    • Korean Journal of Food Science and Technology
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    • v.31 no.6
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    • pp.1667-1678
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    • 1999
  • Certain parts of 190 kinds of medicinal herbs and 171 kinds of original materials of food were extracted by methanol. The extracts were tested their microbial inhibition activities against several food spoilage microorganisms, Micrococcus luteus, Bacillus subtilis, Bacillus cereus, Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella typhimurium, Escherichia coli, Saccharomyces cerevisiae, Candida albicans, Penicillium citrinum, Aspergillus flavus and Aspergillus niger. The methanol extracts of Cornus officinalis, Evodia officinalis, Glycyrrhiza glabra, Salvia miltiorrhiza. Schizandrae fructus, Coptidis rhizoma, aroma hop and bitter hop were shown inhibitory effect on certain species of gram(+) bacteria. Aroma hop and bitter hop were shown inhibitory effect on certain species of gram(-) bacteria. The methanol extract of Salvia miltiorrhiza exhibited a strong antibacterial activities. It was purified by solvent fractionation, silicagel column chromatography, prep. TLC, prep. HPLC. The purified active substance was identified as cryptotanshinone by EIMS, $1^H-NMR,\;{13}^C-NMR$ and DEPT. Cryptotanshinone showed a strong antibacterial activity against gram positive bacteria $(MIC\;:\;3.91{\sim}62.50\;{\mu}g/mL)$. Especially, this compound was the most strong activity against Bacillus subtilis $(MIC\;:\;3.91\;{\mu}g/mL)$.

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Effect of Annual Ring Angles on Static Bending Strength Performances of Cross-Laminated Woods Made with Spruce (연륜경사각이 가문비나무 직교형적층재의 정적 휨 강도성능에 미치는 영향)

  • Sung, Eun-Jong;Kwon, Chang-Bae;Ryu, Hyun-Soo;Byeon, Hee-Seop;Park, Han-Min
    • Journal of the Korean Wood Science and Technology
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    • v.42 no.3
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    • pp.290-300
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    • 2014
  • In this study, cross-laminated woods were made with spruce wood and the effects of annual ring angles of perpendicular direction laminae on static bending strength performance were investigated. Static bending strength performances of parallel laminated woods with all layers composed of laminae perpendicular to the grain ($P_{\bot}$ type) were in the order of $90^{\circ}$ > $0^{\circ}$ > $45^{\circ}$. The MOE and MOR for the $45^{\circ}$ annual ring angle were 0.0989 GPa and 3.25 MPa, and it showed the lowest values. By placing longitudinal-direction laminae in the core of $P_{\bot}$ type, the strength performances were markedly improved. In the case of cross-laminated woods with perpendicular-direction laminae in the faces ($C_{\bot}$ type), the bending strength performances were in the order of $90^{\circ}$ > $0^{\circ}$ > $45^{\circ}$, but the differences among annual ring angles were less than those of the parallel-laminated woods. In the case of cross-laminated woods with perpendicular-direction laminae in the core ($C_{\parallel}$ type), the bending strength performances were in the order of $45^{\circ}$ > $90^{\circ}$ > $0^{\circ}$ unlike $P_{\bot}$ type and $C_{\bot}$ type. The MOE and MOR for the $45^{\circ}$ annual ring angle were 12.0 GPa and 55.8 MPa, and it showed the highest values.