• Toxicological Research
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• v.21 no.1
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• pp.31-37
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• 2005

The inhibitory activity against bisphenol-A (BPA), one of well-known endocrine disrupters was examined with the water extracts prepared from the Stem Bark of Syringa velutina (SBS). In this study, we have investigated the effect of SBS on the toxicity caused by BPA in human breast cancer cell line, MCF-7 cells and immature Sprague-Dawley rats. In the estrogen receptor-mediated proliferation assay using MCF-7 cells, BPA (16 ng/ml) induced the cell proliferation, but the water extract of SBS inhibited BPA-induced cell proliferation in a dose-dependent manner. These results are associated with PARP degradation and specific cleavage of anti-apoptotic protein Bcl-2 of apoptotic regulatory factors. Additionally, the BPA (400 mg/100 g) significantly induced the increase of the uterine and virginal weights, while SBS (50 mg/100 g) showed the inhibitory action against BPA, i.e. caused the increase of estrogen-related organ weights in immature rat uterotrophic assay. Taken together, the present data suggest that SBS may have anti-toxicity activities against BPA in vitro and in vivo systems. SBS may be capable of inhibiting adverse effects of BPA such as reproductive disorder.

• Journal of Plant Biotechnology
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• v.44 no.4
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• pp.409-415
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• 2017

The vegetation period of trees might be prolonged by the delay of the leaf senescence in autumn. Thus, we focused on the generation of senescence-delayed transgenic trees to enhance biomass production. The PagMYC2, a gene containing the basic helix-loop-helix domain, was selected as a candidate for a senescence-delayed transgenic tree. The PagMYC2 gene was specifically induced after treatment with phytohormone jasmonic acid, and upregulated by abiotic stresses such as salinity, osmotic pressure and a low temperature. The constitutive overexpression of the PagMYC2 delayed the leaf senescence and inhibited chlorophyll degradation in the transgenic poplars. Leaf senescence analysis was performed in the leaf tissues of the PagMYC2-over-expression transgenic poplars. The transgenic poplars exhibited higher photochemical efficiency than did a wild type plant under a short-day condition (6 hours light/18 hours darkness) or a low temperature condition ($15^{\circ}C$) that was similar to the weather conditions of autumn. These results suggest that the PagMYC2 is a useful genetic resource to improve biomass production, which is able to sustain growth with senescence-delayed leaves for a long time in autumn.

• Journal of Wetlands Research
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• v.21 no.spc
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• pp.16-27
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• 2019

Alteration in the flow regime of rivers are caused by natural climate change and the changes in anthropogenic hydrological environment due to dam construction. These changes in flow regime cause serious changes not only in the fresh water ecosystems of the rivers but also in the physical structures and fish habitats of the streams. In this study, the alteration in the hydrological characteristics of the Gam river basin due to Buhang dam construction and the changes in ecological health condition, water quality, and river cross-section were analyzed. As a result of analysis by indicators of hydrologic alteration (IHA) to quantitatively change the flow regime of Gam river, HA (Hydrologic Alteration) is more than ±1 and various changes have occurred in the river ecosystem after Buhang dam construction. In addition, ecological health condition and water quality showed different response for each element, and in the case of riverbeds and channel cross-sections, the degradation of channel bed was obviously monitored after dam construction. The results of this study are expected to be used as an efficient method for evaluating changes in stream ecosystems caused by stream regime changes.

• The Korean Journal of Mycology
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• v.27 no.1 s.88
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• pp.76-81
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• 1999

Exo-polysaccharide obtained from the submerged cultivation of Ganoderma lucidum mycelium was fractionated. The structural analysis of the acidic exo-polysaccharide fraction (BWS-DA-GI), showing high antitumor activity, was carried out and compared to the mycelial acidic fraction (MWS-DA-GI). The major sugar constituents of the fraction of BWS-DA-GI were glucose, galactose and mannose in the molar ratio of 2.5 : 2.1 : 2.5. The minor components in this fraction were xylose and fucose. While the major sugar constituents of the mycelial acidic fraction of MWS-DA-GI were galactose, fucose, mannose and glucose. The trace components in this fraction was xylose. From the results of periodate oxidation, Smith degradation, affinity chromatography and methylation analysis, the chemical structures of the two fractions, BWS-DA-GI and MWS-DA-GI were both determined as ${\beta}-1,3$ glucans. It was also estimated that BWS-DA-GI had a $1{\rightarrow}6$ glucosidic linkage and MWS DA-GI had $1{\rightarrow}4$ and $1{\rightarrow}6$ glucosidic linkages. The molecular weights of these fractions, MWS-DA-GI and MWSDA-GI were estimated as $1.2{\times}10^6\;and\;1.0{\times}10^6$ dalton, respectively.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.9 no.2
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• pp.73-82
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• 1989

When the flood occurs in the alluvial rivers, the rivers adjust to the flood by means of the mechanism of the river bed variations and its morphological changes to pass that safely, the numerical model was developed to simulate the process of the alluvial river bed variation due to flood wave and carried out by the flood routing for flood wave and the sediment routing for river bed variation. The flood wave, river bed variation, and bed material size distribution may be analysed and predicted by this model. The ability of this model to predict the process of river bed response was proved by the application to the reach from Paldang dam to Indogyo site. In view of the flood analysis considering the sediment process, the effects of river bed variation for the flood routing may be negligible because the river bed variation is smaller than the unsteady flow variation during the same period. By the application of this model, it is shown that, in occurring of sequential flood events, the variation of the river bed and bed material size distribution due to flood wave is more dependent on the first flood event than the latter flood events, and that the river bed variation in this reach of the downstream Han river is dependent on the degradation and the coarsening of bed materials.

• Journal of Plant Biotechnology
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• v.45 no.2
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• pp.90-101
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• 2018

Strawberry (Fragaria ${\times}$ ananassa) is a globally-cultivated and popular fruit crop, prized for its flavor and nutritional value. Sweetness, a key determinant of fruit quality, depends on the sugar composition and concentration. We selected eight strawberry cultivars based on the fruit soluble solids content to represent high and low sugar content groups. The average soluble solid content was $13.6^{\circ}Brix$ (Okmae, Geumsil, Aram, and Maehyang) and $2.9^{\circ}Brix$ (Missionary, Camino Real, Portola, and Gilgyung53), for the high and low sugar content groups, respectively. Sucrose was the main sugar in the cultivars with high sugar content, whereas fructose was the main component in the low sugar content cultivars. Fruit starch concentration ranged from $3.247{\pm}0.056$ to $3.850{\pm}0.055g/100g$, with a 12% higher concentration in the high sugar content cultivars. Additionally, we identified 41 sugar metabolism-related genes in Fragaria ${\times}$ ananassa and analyzed the relationship between their transcripts and the sugar accumulation in fruit. FaGPT1, FaTMT1, FaHXK1, FaPHS1, FaINVA-3, and FacxINV2-1 were highly expressed in the high sugar content cultivars, while FapGlcT, FaTMT2-1, FaPHS2-1, FaSUSY1-1, and FaSUSY1-2 were highly expressed in the low sugar content cultivars. In general, a greater number of genes encoding sugar transporters or involved in sugar synthesis were highly expressed in the high sugar content cultivars. Contrarily, genes involved in sugar degradation were preferentially transcribed in the low sugar content cultivars. Although gene expression was not perfectly proportional to sugar content or concentration, our analysis of the genes involved in sugar metabolism and accumulation in strawberries provides a framework for further studies and for the subsequent engineering of sugar metabolism to enhance fruit quality.

• Textile Coloration and Finishing
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• v.17 no.2 s.81
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• pp.31-39
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• 2005

This study was conducted to remove the dyes in dye wastewater by the chemical precipitation or biological treatment which are one of the main pollutants in dye wastewater. In order to remove the disperse dyes effectively in aqueous solution by chemical precipitation process, coagulation and flocculation tests were carried out using several coagulants on various reaction conditions. It was found that the Ferrous sulfate was the most effective coagulant for the removal of disperse dye(DB79), and we could get the best result for the removal of disperse dye(DB56) in the aspects of TOC removal efficiency and sludge yield. When the Ferrous sulfate dosage was 800mg/l, the sludge settling velocity was very fast$(SV_{30}=4\%)$, and the color was effectively removed in the disperse dye(DB79) solution. Although the color removal was ineffective when the Alum was used as a coagulant, the sludge yield decreased in comparison with the Ferrous sulfate or the Ferric sulfate being used in the disperse dye(DB56) solution. In order to decolorize disperse dye(DR17) by using biological treatment process, a strain which has potential ability to degrade disperse dyes was isolated from natural system. The optimal culture conditions of temperature and pH were found to be $40^{\circ}C\;and\;8.5\~9$, respectively. When yeast extract was mixed with polypeptone at the mixing ratio of 1:1 as a nitrogen source, decolorization efficiency was highest$(93\%)$ among the nitrogen sources. The strain screened was excellent to adjust to pH, and it seems to have ability to control pH needed to growth. The optimal culture conditions in concentration of $MgSO_{4.}\cdot7H_2O\;and\;KH_2PO_4$ were $0.1\%(w/v)\;and\;0.2\%(w/v)$, respectively. Strains degrading and decolorizing reactive dyes, RB198 and RR141 which were isolated from water system, are named RBK1 and RRK. And the cell growth characteristics of RBK1 and RRK were investigated. The optimal culture conditions of temperature and pH were found to be 30t' and 7.0, respectively. Optimum nitrogen source was peptone, and it was found that decolorization efficiencies by strains RBK1 and RRK, were $85\%\;and\;62\%$, respectively, with introduction of 4,000mg/l of peptone. In the case of RBK1, color removal efficiencies were very high below 400mg/l. Decolorization efficiency was over $90\%$ at 20hours of culture time. The Color degradation ability of RRK was lower than that of RBK1.

• Journal of the Korean Society for Marine Environment & Energy
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• v.11 no.4
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• pp.227-231
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• 2008

The purpose of this study is to clarify the behavior of stranded crude oil and to estimate the restoration of seawater infiltration by application of dispersant as one of cleaning techniques. We made visualization of infiltration process of seawater and stranded crude oil on the sandy beach sediments by using of a model sandy beach. Major conclusions derived from this study are as follows. The seawater infiltration volume was reduced by the stranded crude oil. However, thirty percentage of the sweater infiltration into the sediments was restored by dispersant application to the penetrated oil in sandy beach. The penetration depth of stranded oil were dropped at first falling tide, but were not significantly fluctuated after that. Moreover, oil concentration was most high within the upper 2 cm. The stranded crude oil was broken into small size droplets and dispersed into the sediments by the dispersant application. Therefore, dispersant applications play an important roles in the large increase of surface area of given volume of oil, and it resulted in promoting to biological degradation process at the oil/water interface, dispersing the stranded oil into the water column and restoration of the supplement of the dissolved oxygen and nutrients to the benthic organisms.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.6
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• pp.723-730
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• 2016

Domestic Manila clam production has been reduced due to coastline changes and environmental degradation, but aquaculture industry is facing difficulties caused by an increase in imports. It is important to recognize the integral habitat environment in order to do sustainable aquaculture. The habitat environment of Manila clams (Ruditapes philippinarum) is closely related to the productivity of aquaculture farms. This study investigated 3 indexes, survival (sediment type, hydrodynamic), growth (Chlorophyll a, DIN, DIP) and environment (water temperature, dissolved oxygen, sediment chemical oxygen demand, ignition loss) as indicators of habitat characteristics for a tidal flat farm in Geunso Bay (Pado and Beopsan) from June 2015 to May 2016. As a result, Pado (maximums.; sand 48.76 %, hydrodynamic 10.59 cm/s, Chlorophyll a 12.70 ug/L, exposure time 3 hours, DO 18.65 mg/L) had a higher sand content, faster current speed, more abundant nutrients and DO, providing more favorable conditions for Manila clams than Beopsan (maximums.; sand 37.40 %, hydrodynamic 6.02 cm/s, Chlorophyll a 6.41 ug/L, exposure time 7 hour, DO 14.81 mg/L). In fact, Pado showed a higher density than Beopsan. This study considered the habitat environments of Pado and Beopsan to provide a basis for optimal management practices and potential suitable sites in Geunso bay.

• The Korean Journal of Pesticide Science
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• v.20 no.3
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• pp.203-210
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• 2016

Polychlorinated biphenyls (PCBs) are ubiquitous environmental contaminants, found in the many environments. PCBs exerts various toxicological effects, including endocrine-disrupting activity. Most researches with these toxicants performed with soil matrix with mixtures of congeners, namely Aroclor, while the biological activities have been tested with animals. However, studies with pure congeners are limited. In this study, 5 congeners were synthesized and their fates (bioaccumulation, degradation, kinetics) were studied in carrot-soil system. The soil half-lives of biphenyl, PCB-1, PCB-3, PCB-77, and PCB-126 were 20.2, 16.0, 11.6, 46.5, 198.0 days, respectively. In general, the longer half-lives were observed with the higher hydrophoicity of PCBs. Times, required for maxium accumulation of PCBs in carrot (Tmax) were 10-20 days for most congeners and the concentrations were 0.4-2.6 mg/kg. The concentrations of PCBs in carrot were kept as constant after Tmax, except PCB-126. The concentration ratio between carrot and soil after 90 days of treatment were 1.7, 8.1, 1.9, 1.8, and 5.9 for biphenyl, PCB-1, PCB-3, PCB-77, and PCB-126. Because of the increase of biomass, the total residual amount of PCBs in carrots however, increased till the end of experiment. The portions of PCB-126 in carrot were 1.1% of the soil residues at 90 days after planting.