• Environmental Mutagens and Carcinogens
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• v.24 no.2
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• pp.91-98
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• 2004

Although 2,3,7,8-tetrachlorodibenzo-p-dioxin(TCDD) is a powerful carcinogen in several species, limited model system exist to study carcinogenicity of this compound at cellular level. To enhance our under-standing of carcinogenicity of TCDD at cellular level, we investigated micronucleus (MN) frequency as a index of genetic toxicity and whether TCDD can transform the human cells in culture. Normal human cell lines, skin keratinocyte HaCaT, Chang liver and breast MCF10A cells were used. TCDD did not affect the cell viability of the Chang liver, HaCaT and MCF10A cells. The frequency of micronucleus was increased after treatment of TCDD for 24hr in Chang liver and HaCaT cells, but not changed in MCF10A cells. And we observed putative transformed cells in Chang liver cells exposed to 1 $\mu$M TCDD for 2 weeks. The putative transformed cells were also observed in HaCaT cells with subsequent exposure to TCDD (0.1, 1, 10, 100 nM) for 2 weeks after initial exposure to MNNG, but not observed in MCF10A cells. Collectively, these results indicate that the ability of TCDD to induce micronuclei may be involved in cellular transformation of Chang liver and HaCaT cells. Our putative TCDD-transformed cells of Chang liver and HaCaT are expected to provide a clue to the elucidation of TCDD-induced transformation pathway.

• Korean Journal of Environmental Biology
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• v.22
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• pp.63-70
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• 2004

Tributyltin (TBT) and its degradation products, dibutyltin (DBT) and monobutyltin (MBT) were quantitatively determined in surface sediments and two molluscan species, Pacific oyster (Crassostrea gigas) and rock shell (Thais ctavigera), from Gwangyang Bay, Korea. Butyltin compounds were detectable in almost all sediment and biota samples. Tributyltin concentrations in surface sediment ranged<2∼33 ng g$\^$-1/, which is at a lower end of TBT concentrations in industrialized bays in Korea. However, TBT levels in sediments were related to boating activities around the bay. In biota samples, TBT concentrations were in the range of 178∼2,458 ng g$\^$-1/ toy oyster and 47∼236 ng g$\^$-1/ for rock shell. Relatively high TBT concentrations in biota were found near wharves for fisherboats and harbor areas. About 90∼100％ of the female T. clavigera displayed imposex, and relative penis length index of the imposexed-female was in the range of 20.9∼107.9％. Furthermore, TBT body residue had a significant positive relationship with degree of imposex in T. clavigera. Overall, TBT concentrations in Gwanyang Bay were much lower than other major bays in Korea.

• Natural Product Sciences
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• v.17 no.4
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• pp.315-320
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• 2011

Routinely applicable HPLC assay procedures for the ganglioside content in various deer antler preparations were established through the creation of a UV-absorbing chromophoric substance - trans-${\alpha},{\beta}$-unsaturated-hexadecene-aldehyde - from the sphingosine moiety in ganglioside molecules by two step chemical reactions. In order to guarantee the assay's accuracy and sensitivity, the HPLC-assay procedure adopted internal reference procedures by mixing cis-${\alpha},{\beta}$-unsaturated-hexadecene aldehyde[V] or cis-3-heptadecene- 1,2-diol[IV] to assay samples. The internal reference compound [IV] or [V] was synthesized in our laboratory starting from mannitol-diacetonide through three or four step organic reactions. This new HPLC-assay procedure was successfully applied to deer antler extracts with good dose-dependent calibration curves at the picomole level of gangliosides.

• Korean Journal of Pharmacognosy
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• v.48 no.1
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• pp.5-9
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• 2017

This study was carried out to obtain the basic information that can be used to index Acanthopanax in eleven species of China and Korea. The phytochemical components from the berry of Acanthopanax species, were measured by the HPLC analysis. Protocatechuic acid, eleutheroside B, eleutheroside E, scopolin, rutin, hyperoside, chiisanoside, oleanolic acid were found in ethanol extracts from the berry of Acanthopanax species. Total phenolic compound of Acanthopanax sessiliflorum f. chungbuensis berry (0.682%) was about seven times higher than those of Acanthopanax divaricatus f. distigmatis berry (0.091%). As a result, the order of the eleutheroside E content was 1) Acanthopanax sessiliflorum f. chungbuensis (0.554%), 2) A. divaricatus var. albeofructus (0.501%), 3) A. divaricatus f. flavi-flos (0.452%). And also, the order of the chiisanoside content was 1) Acanthopanax senticosus var. subinermis (8.434%), 2) A. seoulense (0.94%), 3) A. divaricatus f. flavi-flos (0.798%).

• Korean Journal of Food Science and Technology
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• v.20 no.5
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• pp.732-735
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• 1988

Flavor stability of cooking oils such as rice bran oil, double fractionated palm olefin and soybean oil were determined by headspace analysis using gas chromatography. In the headspace, the contents of volatile compounds, oxygen and hydrogen were measured. The hydrogen content in the headspace correlated well with the contents of volatile compound (r > 0.95). Therefore, it is proposed that a single measurement of hydrogen and oxygen is used as a index of flavor stability of cooking oils instead of separate measurement of volatile compounds and oxygen. which have conventionally been used.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.23
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• pp.10137-10142
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• 2015

Apoptosis is a general phenomenon of all multicellular organisms and caspases form a group of important proteins central to suicide of cells. Pathologies like cancer, Myocardial infarction, Stroke, Sepsis, Alzheimer's, Psoriasis, Parkinson and Huntington diseases are often associated with change in caspase 3 mediated apoptosis and therefore, caspases may serve as potential inhibitory targets for drug development. In the present study, two series of synthetic acetylated tetrapeptides containing aldehyde and fluromethyl keto groups respectively at the C terminus were proposed. All these compounds were evaluated for binding affinity against caspase 3 structure. In series 1 compound Ac-DEHD-CHO demonstrated appreciable and high binding affinity (Rerank Score: -138.899) against caspase 3. While in series 2 it was Ac-WEVD-FMK which showed higher binding affinity (Rerank Score: -139.317). Further these two compounds met ADMET properties and demonstrated to be non-toxic.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.1
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• pp.44-48
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• 1999

Uptake, assimilation and translocation of nitrogen and dry matter assimilation and translocation in ten rice cultivars were observed in no-till direct-sown rice-vetch cropping system. There was a large degree of variation in N-uptake, grain yield, nitrogen translocation efficiency and dry matter assimilation and translocation in tested rice cultivars. Forty kg N/ha base, as compound fertilizer (21-17-21% of N-P-K) three weeks after sowing and 30 kg N/ha top-dressed at panicle initiation stage as in the form of (NH$_4$)$_2$$CO_2$ was applied. ‘Newbounet’, ‘Daesanbyeo’, and ‘Hwayeongbyeo’ showed higher translocation efficiency. The contribution of pre-heading dry matter assimilates to grain ranged from 33% to 99% of dry grain weight. Dry matter of ‘Calrose 76’ was lower than Newbounet but N content was higher in Calrose 76 than Newbonnet. By maturity, N content in vegetative parts declined considerably more than dry matter, vegetative and reproductive parts, N translocation efficiency, and N harvest index. Nitrogen translocation efficiency was greater in ‘Nonganbyeo’, Daesanbyeo, and Newbounet. Grain N concentration was positively correlated with N concentration or N content of the vegetative parts at heading in Nonganbyeo, ‘Dasanbyeo’, ‘Dongjinbyeo’, and Newbonnet. These results indicated that the greater amount of dry matter and N accumulated before heading stage, the higher translocation rates of dry matter to grain and the greater net losses at maturity.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.10
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• pp.999-1006
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• 2004

Recently, the ride comfort problem becomes increasingly important because of today's needs for train speedup. The railway has the track irregularities which cause vibrations, such as rail joints, turnout, level crossing, transition corves and super-elevation ramps, and variations in the track level(z-axis) and the gauge(y-axis). In Korea, the service run of the high speed train has been made since the 1st of April, 2004. The commercial high-speed trains must be run on the compound lines which are composed of high-speed line and conventional line. The high speed lines in both Kyoungbu line and Honam line have 57.5％ and 33.8％, respectively In this Paper, the ride comfort has been reviewed by the various experimental methods when the high-speed trains are operated on both Kyoungbu line and Honam line. The results show that the high-speed train has no problems from the viewpoint of the comfort ride during the operation on the high speed line and conventional line.

• International Journal of Automotive Technology
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• v.4 no.2
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• pp.95-100
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• 2003

Automobile industry has been developed rapidly as a key manufacturing industry in Korea. Meanwhile, air pollution is getting worse noticeably than ever. In the diesel emission, PM (Particulate Matter) and NOx (Nitrogen Oxides) have been exhausted with a great amount and the corresponding emission regulations are getting stringent. In order to develop low emission engines, it is necessary to research on better qualified fuels. Sulfur contained in fuel is transformed to sulfur compound by DOC (Diesel Oxidation Catalyst) and then it causes to the increase of sulfate-laden PM on the surface of catalyst. In this research, ULSD (Ultra Low Sulfur Diesel) is used as a fuel and some experimental results are investigated. ULSD can reduce not only PM but also gas materials because cetane value, flash point, distillation 90%, pour point and viscosity are improved in the process of desulfurization. However, excessively reduced sulfur may cause to decease lubricity of fuel and engine performance in fuel injection system. Therefore, it requires only modest adjusted amount of sulfur can improve engine performance and DOC, as well as decrease of emission.

• Economic and Environmental Geology
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• v.26 no.2
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• pp.217-226
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• 1993

Stream sediment samples were collected in the vicinity of the Sambo Pb-Zn-barite mine in order to investigate dispersion patterns and pollution levels of heavy metals, and to find out their mode of occurrences. Those samples were analyzed for Cd, Cu, Pb, Zn, Fe, and Mn by using partial extraction and sequential extraction methods. Stream sediments of this studied area has been contaminated severely by Pb, Zn, and Cd. Dispersion patterns of heavy metals in those sediments are different according to their pollution source and sampling distance from the mine. The stream sediment pH is generally neutral in control area, and is slightly acidic in the lower part of tailing dam. The main pollution source of stream sediments was confirmed as tailing and mine drainage. Their pollution level depends mainly on inflowed water and distance from the mine. The tolerance index ranges from -0.9 to 0.7. The mode of occurrances of heavy metals in polluted stream sediment are identified as Fe-Mn oxides, organic bounded and carbonate-bounded compound which show high potential of bioavailablity.