• Korean Journal of Environment and Ecology
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• v.25 no.1
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• pp.57-64
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• 2011

A field survey was conducted from June 2005 to September 2007 to explore changes of the vegetation and life form in the man-made Wetland along the Sinpyeongcheon for 3 years after its creation. A total of 20 species including 14 families, 18 genera, 15 species and 5 varieties were planted in the Wetland which was completed in 2004. Divided by life form of the planted species, a prevalent 65% of them was composed of perennation while 4 species of woody plants i.e. Fraxinus rhynchophylla, Salix glandulosa, Camellia japonica and Nandina domestica were planted there, too. The 3-year study revealed that hydatophytes (HH) scored the biggest increase in number, followed by slight increase in the number of microphanerophytes (M), megaphanerophytes (MM), chamaephytes (Ch), nanophanerophytes (N), perennial plants (H), etc., featuring generally a similar tendency for the whole period of study. The change in vegetation area increases in the area of Typha angustata, Phragmites japonica, Phragmites communis, etc. but a sharp decrease in the area of communities for other planted species. In terms of change in the area for planted species by their life form, hydatophytes (HH), HH Th (Th(w)) reported gradual increase while microphanerophytes (M), geophyte (G), and nanophanerophytes (N) continued to record a decrease. In conclusion, selection of plants to be planted turns out to play a vital role in molding the destiny of a man-made Wetland. It seems therefore extremely important to investigate the flora, and life and growth forms of the plants planted in the man-made Wetland in an effort to choose the species that can adapt themselves to the environment from the early phase on, contributing by thus to stabilization and diversification of the damp ground in line with the progression of their succession.

• Journal of Biosystems Engineering
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• v.5 no.1
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• pp.1-14
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• 1980

Threshing operation may be one of the most important processes in the paddy post-production system as far as the grain loss and labor requirement are concerned . head-feeding type threshers commercially available now in Korea originally were developed for threshing dry paddy in the range of 15 to 17 % in wet basis. However, threshing wet-paddy with the grain moisture content above 20 % has been strongly recommended, especially for new high-yielding Indica -type varieties ; (1) to reduce high grain loss incurred due to the handling operations, and (2) to prevent the quantitative and qualitative loss of milled -rice when unthreshed grains are rewetted due to the rainfall. The objective of this study were to investigate the adaptability of both a head-feeding type thresher and a throw-in type thresher to wet-paddy , and to find out the possiblilities of improving the components of these threshers threshing. Four varieties, Suweon 264 and Milyang 24 as Tongil sister line varieties, minehikari and Jinhueng as Japonica-type varieties, were used at the different levels of the moisture content of grains. Both the feed rate and the cylinder speed were varied for each material and each machine. The thresher output quality , composition of tailing return, and separating loss were analyzed from the sampels taken at each treatment. A separate experiment for measurement opf the power requirement of the head-feeding type thresher was also performed. The results are summarized as follows : 1. There was a difference in the thresher output quality between rice varieties. In case of wet-paddy threshing at 550 rpm , grains with branchlet and torn heads for the Suweon 264 were 12 % and 7 % of the total output in weight, respectively, and for the Minehikari 4.5 % and 2 % respectively. In case of dry paddy threshing , those for the Suweon 264 were 8 % and 5% , and for the Minehikari 4% and 1% respectively. However, those for the Milyang 23 , which is highly susceptable to shattering, were much lower with 1 % and 0.5% respectively, regardless of the moisture content of the paddy. Therefore, it is desirable to breed rice varieties of the same physical properties as well as to improve a thresher adaptable to all the varieties. Torn heads, which increased with the moisture content of rall the varieties except the Milyang 23 , decreased as the cylinder speed increased, but grains with branchlet didnt decrease. The damaged kernels increased with the cylinder speed. 3. The thresher output quality was not affected much by the feed rate. But grains with branchlet and torn heads increased slightly with the feed rate for the head-feeding type thresher since higher resistance lowered at the cylinder speed. 4. In order to reduce grains with branchlet and torn heads in wet-paddy threshing , it is desirable to improve the head-feeding type thresher by developing a new type of cylinder which to not give excess impact on kernels or a concave which has differenct sizes of holes at different locations along the cylinder. 5. For the head-feeding type thresher, there was a difference in separating loss between the varieties. At the cylinder speed of 600 rpm the separating losses for the Minehikari and the Suweon 264 were 1.2% and 0.6% respectively. The separating loss of the head-feeding type thresher was not affected by the moisture content of paddy while that of the Mini-aged thresher increased with the moisture content. 6. From the analysis of the tailings return , to appeared that the tailings return mechanism didn't function properly because lots of single grains and rubbishes were unnecessarily returned. 7. Adding a vibrating sieve to the head-feeding type thresher could increase the efficiency of separation. Consequently , the tailing return mechanism would function properly since unnecessary return could be educed greatly. 8. The power required for the head-feeding type thresher was not affected by the moisture content of paddy, but the average power increased linearly with the feed rate. The power also increased with the cylinder speed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.3
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• pp.127-135
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• 2016

Two-pore domain potassium (K2P) channels are the targets of physiological stimuli, such as intracellular pH, bioactive lipids, and neurotransmitters, and they set the resting membrane potential. Some types of K2P channels play a critical role in both apoptosis and tumoriogenesis. Among the K2P channels, no antagonists of the TREK2 channel have been reported. The aim of the present study was to determine if the TREK2 channel is blocked and whether cell proliferation is influenced by flavonoids in the TREK2 overexpressing HEK293 cells (HEKT2). The electrophysiological current was recorded using single channel patch clamp techniques and cell proliferation was measured using a XTT assay. The electrophysiological results showed that the TREK2 channel activity was reduced to $91.5{\pm}13.1%$ (n=5) and $82.2{\pm}13.7%$ (n=5) by flavonoids, such as epigallocatechin-3-gallate (EGCG) and quercetin in HEKT2 cells, respectively. In contrast, the EGCG analogue, epicatechin (EC), had no significant inhibitory effects on the TREK2 single channel activity. In addition, cell proliferation was reduced to $69.4{\pm}14.0%$ (n=4) by ECGG in the HEKT2 cells. From these results, EGCG and quercetin represent the first known TREK2 channel inhibitors and only EGCG reduced HEKT2 cell proliferation. This suggests that the flavonoids may work primarily by inhibiting the TREK2 channel, leading to a change in the resting membrane potential, and triggering the initiation of a change in intracellular signaling for cell proliferation. TREK2 channel may, at least in part, contribute to cell proliferation.

• Clinical and Experimental Pediatrics
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• v.48 no.1
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• pp.40-47
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• 2005

Purpose : S. pneumoniae is one of major pathogens of community-acquired respiratory infections. The rate of antibiotic resistance to this organism has increased, and resistance to multiple antimicrobial agents in a single strain of S. pneumoniae may compromise the efficacy of empiric antimicrobial treatment commonly used for respiratory infections. We did this study to find out the penicillin resistant distributions and oral antibiotics susceptibility patterns against S. pneumoniae, isolated from pediatric patients with community-acquired respiratory infections in Korea. Methods : One hundred fifty six pneumococcal isolates obtained from pediatric patients with community-acquired respiratory infections such as acute otitis media(AOM), sinusitis and pneumonia between May 2000 to June 2003. And MICs of penicillin and oral antibiotics(amoxicillin, amoxicillin-clavulanate, cefaclor) were performed by broth microdilution methods according to the NCCLS(2003a). Results : Seventy eight percent of the isolates were resistant to penicillin. The isolates, collected from AOM patients showed the highest penicillin resistance(92.7%). The resistant rates of amoxicillin (16.7%) and amoxicillin-clavulanate(9.6%), based on susceptibility breakpoints established by the NCCLS, were markedly lower than these of penicillin. But, the resistant rate of cefaclor was very high, above 95%. Conclusion : We concluded that pneumococci isolated from study cases may be one of the world's highest penicillin resistant rates. But, amoxicillin and amoxicillin-clavulanate can be used as a first-line antibiotics. Finally, we hope that a continuous surveillance study to monitor resistant patterns of pneumococcal respiratory infections will be needed for the standard guidelines of empiric antibiotic treatment.

• Korean Journal of Poultry Science
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• v.40 no.4
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• pp.299-304
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• 2013

Tracheal epithelial cells (TECs) are an important tool for studies of viral respiratory diseases. Primary TECs have been cultured from human, mouse and hamster. It is also necessary to diagnose viral respiratory disease and reveal infection mechanisms in chicken. In this study, we isolated tracheal epithelial layers from tracheal of 20-day-old chicks and cultured primary TECs from the isolated layers. Ciliated cells which were a typical morphology of TECs were observed in cultured primary TECs and maintained until cell passage 5 (15 to 20 days). When we analyzed expression patterns of epithelial marker genes (retinoic acid responder, FGF-binding protein, virus activating protease (VAP) in TECs compared to immortalized chicken embryonic fibroblast cell line (DF-1), all the marker genes are highly expressed in TECs than in DF-1. When TECs were cultured with 0.1 and 1 MOI of ND virus (rNDV-GFP strain) to test the susceptibility of TECs for ND virus, 12.6% and 48.2% of the incubated TECs were infected respectively. In addition, when DF-1 was incubated with 1 MOI of ND virus, the virus infection rate of DF-1 was three times lower than the virus infection rate of TECs. These data could contribute to study infection mechanisms of viral respiratory diseases and control them in chicken.

• Journal of Plant Biotechnology
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• v.45 no.2
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• pp.117-124
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• 2018

The imports of Centella asiatica L. Urban are increasing year-by-year due to the fact that its extract is a raw material used for skin wounds and in cosmetics. However, studies on the cultivation and identification of native C. asiatica species in Korea have been extremely rare. Therefore, this study was conducted in order to investigate the physiological and functional activity of Korean native C. asiatica plant cultivated in Hapcheon, Gyeongsangnam-do, Korea. As a result, the highest antibacterial and anti-inflammatory activities were examined with methanol extract while skin-whitening and wrinkle improvement were examined with water extract. Seven bacterium and one fungus were treated with 50% methanol extracts of C. asiatica and most of the bacterium showed similar or low levels of antibacterial activity compared to the control group of Omiza (Schisandra chinensis) extract, except for Streptococcus pyogenes, which showed higher antimicrobial activity than that of Omiza extract. However, neither C. asiatica and Omiza extracts showed antimicrobial activity against the fungus, C. albicans. The results of anti-inflammatory effect analyses with Raw 264.7 cells confirmed that the treatment of methanol extract reduced the level of NO by 50% or more compared to the control group. In addition, the water extract showed the highest reduction of melanin content of up to 20% more than the control group when examined with B16F10 cell line, indicating a significant skin-whitening effect. Furthermore, we were able to show the significant skin wrinkle improvement caused by C. asiatica extract with NHDF cell as an indicator, but strong cytotoxicity was also observed, suggesting that further studies are necessary.

• Journal of Preventive Medicine and Public Health
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• v.12 no.1
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• pp.13-23
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• 1979

A study was carried out from October 1977 to September 1978 in order to develope health care delively system which will meet to rural area in Korea. For the study objective a model of health care delivery system of Myun (township) area was developed which is adopted the net-work of village health voluntary worker who will play the role of bridge for communication related with health and illness between families or village people and health subcenter, and :he model health care delivery system net-work was set in the area of Soodong Myun, Yangju Gun. which is the rural health demonstration area of Ewha Womans University since 1972. The activities and attitude of 22 village health voluntary workers were observed and analized. during the study period. The results are as follows; 1. For the field activities of village health voluntary workers. a guide line which is described with specific behavioral objectives was developed and used for not only training of the workers but also evaluation of their field activities. 2. During the study period, the number of 971 village people were served primary health care service by village health voluntary worker and the service was classified largely into symptomatic medications (92%) and preventive measures (8%). 3. Comparative percentage of the number of 894 symptomatic cases cared by village health voluntary workers to 5,695 cases of patient treated by Soodong Health Subcenter during the same period was 15.7%. 4. Annual utility rate of village health voluntary worker by Myun total people was 16.1% but utility rate by Rie was varied from 38.2% to 2.8% which shown there were considerable differences in each Rie. In order to settle the village health care service, the obstructive factors of utility should be detected and their counter measure must be taken. 5. As the health need of village people increases, it is expected that the supplement of drug excluding present sit basic drugs is inevitable, but considering the ability of village health voluntary worker, the selection of additional drugs and education, plan should be carefully studied. 6. It is desirable that a financial resource for supplementary purchase of first aid kit, drugs and materials whould be alloted from village public fund like Saemaeul Women's Club fund, which has already practiced in a few villages in the study area. 7. As pointed out by village health voluntary workers, in order to improve the village health, village leaders should be in the center of it and the cooperation of whole village people is a core of healthful village development, and it is reasonable that the health subcenter backs up these voluntary health activities by village people in techniques. 8. It seems effective that a supplementary education for village health voluntary worker be accomplished by a planned education through regular meetings like worker's monthly meeting and irregular post guide when Myun Health Workers can handle the problems found during the round trip of villages. 9. It is desirable that village health voluntary workers, who are recommended by a civil voluntary organization like Saemael Woman's Club, are charged by natural villagc unit, are given a function of village health care service and used through basic education at health subcenter. 10. It is advisable that the village health voluntary worker's service is compensated not by a form of money, but by other way such as an exemption of medical fee of worker herself or her families in health subcenter can be one method. 11. Daily health activities of each village health voluntary worker should be reported to health subcenter by biweekly or monthly in order to get not only for basic data of the program but also for evaluation the program. It is recomandable that the report form should be simple and clear enough for village health voluntary worker to fill it effectively. 12. Village health care service should be developed into a Saemaeul Movement in which village people actively participate. For this, the appointed function of village health voluntary worker should be absorbed into those of living Environment Betterment Section or Family Planning Section of Saemaeul Women's Club or it is desirable that establish a new section, Village Health Promoting Section and make it involve the appointed functions of those sections mentioned above.

• Childhood Kidney Diseases
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• v.9 no.2
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• pp.213-221
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• 2005

Purpose : Urachal anomalies are rare but are known to develop several complications, especially infection. Moreover, uniform guidelines for management have not been presented because of the variable clinical characteristics of these anomalies. The purpose of this report is to review our experience with urachal anomalies and attempt to determine the optimal management. Methods : We retrospectively reviewed the records of fourteen children with a variety of urachal anomalies who had been treated from January 1996 to June 2005 at Dong Kang General Hospital. Results : The age distribution of the patients(mean age; 3.8 years) was six neonates, one infant, five preschool-age and two school-age children. The male to female ratio was 1:1. Six cases of urachal cyst, four cases of patent urachus, two cases of urachal sinus and two cases of urachal diverticulum were found. Three patients with patent urachus and one with urachal cyst had hydronephrosis. Other associated anomalies included an inguinal hernia in one patient with urachal sinus and a vesicoureteral reflux in one patient with urachal diver ticulum. As a first-line diagnostic tool, high-resolution ultrasound examination was performed in thirteen cases and computed tomography in one case. Surgical excision was performed in nine patients with urachal anomaly. Five cases out of six neonatal cases experienced spontaneous improvement during a three-month follow up period. Due to frequent infection of the umbilicus, surgical excision was performed on one neonate with urachal sinus. Conclusion : All patients with urachal anomalies should undergo investigation for associated anomalies. The neonate with urachal anomalies, especially patent urachus, do not require surgical excision unless the patient has multiple episodes of recurrent infection. (J Korean Soc Pediatr Nephrol 2005;9:213-221)

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.5 no.4
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• pp.320-334
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• 2000

Deep-sea surface sediment were analyzed for their geotechnical properties, and the sediment samples were collected with a multiple-corer from 31 stations along the track line (131$^{\circ}$30'W, 5-12$^{\circ}$N) in the northeast equatorial Paciflc. Most of the sediments from the northern part (8-12$^{\circ}$N) showed typical properties of siliceous sediments, whereas the southern part (5-6$^{\circ}$N) showed calcareous characteristics due to high biogenic carbonate productivity in the surface waters, where its water depth was shallower than the carbonate compensation depth (CCD: 4,400 m). Geotechnical properties changed sharply at the boundary of 7$^{\circ}$N. Calcareous sediments from the southern part had low water contents, low porosity, low shear strength, high bulk density and high specific grain density, whereas siliceous sediments from the northern part attained high water content, high porosity, high shear strength, low bulk density and low specific grain density. Higher sediment activities were observed in the northern sediment samples than the southern sediment samples. The core samples of the northern sediments were divided into a semi-liquid upper layer and a consolidated lower layer with a boundary at 5-8 cm. These sediment samples showed a rapid increasing pattern along the downcore in original shear strength when an opposite trend was observed in the southern samples. The results showed that sediment variabilities in geotechnical properties between the northern and southern parts such as productivities of surface water, grain solubility due to water depth variation, sedimentation rate, erosion and redistribution of sediment, and combined sedimentary processes were distinctly different along the latitude.

• Journal of the Korean Society of Groundwater Environment
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• v.7 no.1
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• pp.32-46
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• 2000

Hydrogeochemical and isotope ($\delta$$^{18}$ O, $\delta$D, $^3$H, $\delta$$^{13}$ C, $\delta$$^{34}$ S, $^{87}$ Sr/$^{86}$ Sr) studies of various kinds of waters (thermal groundwater, deep groundwater, shallow groundwater, and surface water) from the Yusung area were carried out in order to elucidate their geochemical characteristics such as distribution and behaviour of major/minor elements, geochemical evolution, reservoir temperature, and water-rock interaction of the thermal groundwater. Thermal groundwater of the Yusung area is formed by heating at depth during deep circlulation of groundwater and is evolved into Na-HCO$_3$type water by hydrolysis of silicate minerals with calcite precipitation and mixing of shallow groundwater. High NO$_3$contents of many thermal and deep groundwater samples indicate that the thermal or deep groundwaters were mixed with contaminated shallow groundwater and/or surface water. $\delta$$^{18}$ O and $\delta$D are plotted around the global meteoric water line and there are no differences between the various types of water. Tritium contents of shallow groundwater, deep groundwater and thermal groundwater are quite different, but show that the thermal groundwater was mixed with surface water and/or shallow groundwater during uprising to surface after being heated at depths. $\delta$$^{13}$ C values of all water samples are very low (average -16.3$\textperthousand$%o). Such low $\delta$$^{13}$ C values indicate that the source of carbon is organic material and all waters from the Yusung area were affected by $CO_2$ gas originated from near surface environment. $\delta$$^{34}$ S values show mixing properties of thermal groundwater and shallow groundwater. Based on $^{87}$ Sr/$^{86}$ Sr values, Ca is thought to be originated from the dissolution of plagioclase. Reservoir temperature at depth is estimated to be 100~1$25^{\circ}C$ by calculation of equilibrium method of multiphase system. Therefore, the thermal groundwaters from the Yusung area were formed by heating at depths and evolved by water-rock interaction and mixing with shallow groundwater.