• Korean Journal of Ecology and Environment
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• v.37 no.1 s.106
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• pp.87-95
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• 2004

Community dynamics of benthic macroinvertebrates in response to natural disturbances (flooding and water temperature) were investigated in the Suyong and Soktae Streams in Busan from October 1997 to September 1998. Oigochaeta and Chironomus, organic polluted indicators, were dominant and various taxa were observed at the study sites. The density and biomass of two dominant taxa increased in warm months while the indicators were washed away in the flooding season. From October to February when the water temperature was less than $15^{\circ}C$, Oligochaeta appeared to be dominant at the Soktae Stream. In contrast various taxa were collected at the Suyong stream. The densities of Oligochaeta and Chironomus increased at the Soktae and the Suyong streams in March. Due to the big flooding in April, the density of dominant taxa decreased abruptly. The community structure showed differences patterns in the flooding season at two streams from June to August. In the Soktae stream, the density increased in August. The reverse patterns were observed in the Suyong stream, washing out in June followed by slow recovery of densities in the fellowing months. Density and biomass showed relatively higher correlations in most taxa. CCA (Canonocial Correspondence Analysis) showed that taxa was different response to different environmental factors.

• Korean Journal of Medicinal Crop Science
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• v.26 no.2
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• pp.157-169
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• 2018

Background: Cassia tora L., an annual or perennial plant of the Fabaceae family, is traditional medicine with various biological activities, including anti-constipation and, anti-inflammation. Chemical compounds such as anthraquinone glycoside and naphthalene derivatives have been isolated from this plant. Cassia tora L. is a common contaminant of agricultural commodities, but is toxic to cattle and poultry. Methods and Results: To investigate the potential toxicity, Cassia tora L. aqueous extract (CO) was administered orally to rats for 26 weeks at 0 (control), 300, 1,500 and 3,000 mg/kg/day (n = 10 for male rats for each dose). The positive control comprised animals orally administered anthraquinone 100 mg/kg/day. There was no treatment-related mortality. An increase in the kidney weight was observed at 3,000 mg/kg/day of CO and anthraquinone 100 mg/kg/day. Macrophage infiltration in the colon was observed at CO 1,500 and 3,000 mg/kg/day and anthraquinone 100 mg/kg/day, but there were no significant toxicological changes in the incidence and severity of the finding. Conclusions: The oral no-observed-adverse-effect level (NOAEL) of CO was 3,000 mg/kg/day in male rats and no target organs were identified. In addition, 300 mg/kg was found to be the no-observed-effect level (NOEL) for systemic toxicity under the conditions of the study.

• Journal of Life Science
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• v.28 no.9
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• pp.1016-1021
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• 2018

Clostridium difficile toxin A causes pseudomembranous colitis. The pathogenesis of toxin A-induced colonic inflammation includes toxin A-dependent epithelial cell apoptosis, resulting in the loss of barrier function provided by epithelial cells against luminal pathogens. Toxin A-dependent epithelial cell apoptosis has been linked to toxin A-induced production of reaction oxygen species and subsequent p38MAPK activation; $p21^{CIP1/WAF1}$ upregulation-dependent cell cycle arrest; cytoskeletal disaggregation; and/or the induction of Fas ligand on epithelial cells. However, the molecular mechanisms underlying toxin A-induced apoptosis remain poorly understood. This study tested whether toxin A could block the Wnt signaling pathway, which is involved in gut epithelial cell proliferation, differentiation and antiapoptotic progression. Toxin A treatment of nontransformed human colonocytes (NCM460) rapidly reduced ${\beta}$-catenin protein, an essential component of the Wnt signaling pathway. Exposure of mouse ileum to toxin A also significantly reduced ${\beta}$-catenin protein levels. MG132 inhibition of proteasome-dependent protein degradation resulted in the recovery of toxin A-mediated reduction of ${\beta}$-catenin, indicating that toxin A may activate intracellular processes, such as $GSK3{\beta}$, to promote degradation of ${\beta}$-catenin. Immunoblot analysis showed that toxin A increased active phosphorylation of $GSK3{\beta}$. Because the Wnt signaling pathway is essential for gut epithelial cell proliferation and anti-apoptotic processes, our results suggest that toxin A-mediated inhibition of the Wnt signaling pathway may be required for maximal toxin A-induced apoptosis of gut epithelial cells.

• Economic and Environmental Geology
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• v.38 no.2 s.171
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• pp.165-176
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• 2005

Natural gas in deep sediment may occur in three phases based on the physical and chemical conditions. If the concentration of gas in pore water is less than the solubility, gas is dissolved. If the concentration of gas is greater than its solubility (water is saturated or supersaturated with gas), gas occurs as a fee gas below the gas hydrate stability Lone (GHSZ) and is present as solid hydrate within the GHSZ. The knowledge of gas concentration in deep sediment appears critical to determine the phase of natural gases and to understand the formation and distribution of gas hydrate. However, reliable data on gas concentration are usually available only from the upper section of marine sediment by the headspace gas technique, which is widely used for sampling of gases from the sediments. The headspace gas technique represents only a fraction of gases present in situ because sediments release most of the gases during recovery and sampling. The PCS (Pressure Core Sampler) is a downhole tool developed to recover a nominal $1{\cal}m$ long, $4.32{\cal}cm$ diameter core containing $1,465cm^3$ of sediment, pore water and gas at in situ pressure up to 68.9 MPa. During Leg 204, the PCS was deployed at 6 Sites. In situ methane gas concentration and distribution of gas hydrate was measured by using PCS tool. Characteristics of methane concentration and distribution is different from site to site. Distribution of gas hydrate in the study area is closely related to characteristics of in situ gas concentration measured by PCS.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.10 no.2
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• pp.173-178
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• 2007

Purpose: This study was conducted to analyze the clinical manifestation and natural course of benign transient hyperphosphatasemia (BTH) in children. Methods: A total of 17 children diagnosed with BTH between June 2006 and July 2007, were included in this study. Clinical records and laboratory tests were analyzed retrospectively for all children. Results: The mean age of the patients was $26.9{\pm}13.8$ months (range: 9 to 49 months). Nine of the 17 BTH cases (52.9%) occurred in patients that had previously suffered from infectious diseases. While the patients were suffering from BTH, the mean serum level of alkaline phosphatase (ALP) was $2,500.2{\pm}1,165.1$ U/L, however, these elevated serum ALP levels normalized within 7 weeks of recovery in all cases. In addition, a seasonal peak in the onset of BTH was observed from September to December. Further, the measurement of ALP isoenzymes in 7 of the patients with BTH, revealed a marked elevation of bone fraction. Conclusion: It is important for pediatricians to understand the clinical manifestation and benign course of BTH to avoid unnecessary diagnostic evaluation in children showing a transient increase in ALP activities.

• Journal of Korea Spatial Information System Society
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• v.12 no.1
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• pp.57-65
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• 2010

In this study, disaster damage investigation system was developed using high resolution satellite images and GIS technique to afford effective damage investigation system for widely disaster damaged area. Study area was selected in Bonghwa, Gyungsangbukdo where high magnitude of damages from torrential rain has occurred at July in 2008. GIS DB was built using 1:5,000 topographic map, cadastral map, satellite image and aerial photo to apply for investigation algorithm. Disaster damage investigation system was developed using VB NET languages, ArcObject component and MS-SQL DBMS for effective management of damage informations. The system can finding damaged area comparing pre- and post-disaster images and drawing damaged area according to the damage item unit. Extracted object was saved in Shape file format and overlayed with background GIS DB for obtaining detail information of damaged area. Disaster damage investigation system using high resolution spatial images can extract damage information rapidly and highly reliably for widely disaster areas. This system can be expected to highly contributing to enhance the disaster prevention capabilities in national level field investigation supporting and establishing recovery plan etc. This system can be utilized at the plan of disaster prevention through digital damage information and linked in national disaster information management system. Further studies are needed to better improvement in system and cover for the linkage of damage information with digital disaster registry.

• Korean Journal of Ecology and Environment
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• v.38 no.2 s.112
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• pp.146-159
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• 2005

Fifty-four zooplankton species from Daecheong Lake were identified during the research period from June to October 2001. The representative zooplanktons mostly comprised the index species indicating the intermediate stage from oligosaprobity to ${\beta}$-mesosaprobity. During the blooming season of blue-green algae, the population of large cladocerans like Daphnia galeata precipitously decreased in size, while rotifers and small cladocerans like Bosmina longirostris increased in population size. Therefore, soon after the peak of the blooming of blue-green algae, whole zooplankton standing crop and number of species showed the tendency of recovery, or even the sharp increase. The population size of Daphnia galeata was affected very sensitively by the change of cyanobacterial density.

• Journal of Applied Biological Chemistry
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• v.55 no.1
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• pp.55-59
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• 2012

We designed a new rapid detection method for volatilized formaldehyde from wood. The process was installed with volatilizing and collecting parts in an incubator. For rapid sampling of formaldehyde from wood, we pulverized the wood to sawdust, and used 0.15-2.0 mm particles for the tests. The highest sampling rate (94.8%) was obtained at 40 mL/min flow rate and $100^{\circ}C$. Under the optimized condition, we could collect the volatilized formaldehyde with good recovery rate. The developed method was applied to the monitoring of the formaldehyde from wood, and the measured concentrations were 0.7-4.6 ${\mu}g/g$ from natural wood, 5.9-12.3 ${\mu}g/g$ from preserved wood, and 5.9-211.5 ${\mu}g/g$ from chemical adhesive processed wood. From the results, we identified natural wood sawdust and chemically processed wood (medium density fiberboard, high density fiberboard, particle board) by the formaldehyde contents except preserved wood.

• Applied Microscopy
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• v.32 no.3
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• pp.231-246
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• 2002

This study was carried out to investigate the effect of squalene (SQ) on the mouse hepatotoxicity induced by cadmium. ICR male mouse weighting about 30 gm were injected $CdCl_2$ (5.0 mg/kg) and SQ (180 mg/kg) into intraperitoneal. At the 1, 2, 3, 4, 5, 6, 7 days, livers were treated with superoxide dismutase (SOD) activity and transmission electron microscopical method and then observed with electron microscope. The results obtained were summarized as follows: SOD activity in the liver, Group A was higher than in normal. Group B was lower than in Group A. In the histological observation, nucleus of Group A showed irregular shape. Inner cavity of mitochondria swellen and development of cristae weakened. Swelling of Lamellae of rough endoplasmic reticulum (RER) showed. Nucleus of group B showed normal shape. Typical lamellae of RER were observed. These results described above treatment of SQ decreased the hepatotoxicity of the $CdCl_2$ and SOD activity in the mouse liver, and then it suggests SQ may be effective for the recovery of hepatic cell.

• Korean Journal of Food Science and Technology
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• v.16 no.1
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• pp.78-82
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• 1984

Effects of various drying conditions of agar gel on the physico-chemical properties of dried agar were investigated. For drying of the agar gel$(1.0{\times}1.0{\times}34.0cm)$ by means of sun drying, simple solar drying, hot-air drying ($30^{\circ}C$, control, natural convection), hot-air drying ($30^{\circ}C$, pretreatment, natural convection) and freeze drying, it took 96, 75, 67, 50 and 21 hours, respectively. The gel strengths of dried agar gel prepared by sun drying, solar drying, freeze drying and spray drying were320, 370, 270 and $360g/cm^2$, respectively and that of hot air-dried agar gel was influenced by drying temperature, pretreatment an mode of heat transfer. The gel strength, the gelation temperature and other quality index of spray-dried agar were not inferior to those of sun-dried agar, but it was not expected to be economical because of it recovery rate. In case of hot air drying, the gel strength value of agar increased as the drying rate increased. No significant differences among various products were noted in the gelation temperature, the melting temperature, the ash and $SO_3$ content.