• 한국환경과학회지
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• 제14권3호
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• pp.351-358
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• 2005

The research in this paper was carried out to examine the BTEX(Benzene, Toluene, Ethylbenzene, Xylene) concentrations in Seongseo Industrial Complex. These compounds are the major constituents, more than $60\%$ in composition of total VOCs, mainly charging in ambient air. BTEX samples were collected from the 38 sites, 10 for the source points and 18 for the boundary sites, and were analyzed by canister-GC/MS. The mean concentrations of BTEX were 33 ppbv for benzene, 214 ppbv for toluene, 89 ppbv for ethyl benzene, 77 ppbv for xylene. Among the BTEX, toluene had the highest concentration in the source points and boundary sites. In the source points, BTEX concentration of incineration facility for hazardous wastewater appeared highly in the range of 220­350 ppbv. BTEX concentrations in source boundary sites appeared in the order of toluene>ethylbenzene>xylene>benzene. As a result of the correlation analysis, the concentration of the source points was related to those of the boundary sites. Correlation of ethylbenzene and xylene was presented to 0.7991(P<0.0 1),\;0.6329(P<0.05) as the correlation coefficient, respectively.

• Journal of Microbiology and Biotechnology
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• 제15권1호
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• pp.161-174
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• 2005

Abstract Glycolysis has a main function to provide ATP and precursor metabolites for biomass production. Although glycolysis is one of the most important pathways in cellular metabolism, the details of its regulation mechanism and regulating chemicals are not well known yet. The regulation of the glycolytic pathway is very robust to allow for large fluxes at almost constant metabolite levels in spite of changing environmental conditions and many reaction effectors like inhibitors, activating compounds, cofactors, and related metal ions. These changing environmental conditions and metabolic reaction effectors were focused on to understand their roles in the metabolic networks. In this study, we have investigated for construction of the regulatory map of the glycolytic metabolic network and tried to collect all the effectors as much as possible which might affect the glycolysis metabolic pathway. Using the results of this study, it is expected that a complex metabolic situation can be more precisely analyzed and simulated by using available programs and appropriate kinetic data.

• Journal of Microbiology and Biotechnology
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• 제7권1호
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• pp.56-61
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• 1997

A strain producing immunosuppressive substances was isolated from a soil in Cheju island. By morphological, cultural, and physiological studies, the strain was identified as Streptomyces lydicus MCY-524. Cultured broth was purified by silica gel, sephadex LH-20 and preparative HPLC and gave two immunosuppressive compounds, MCH-22 and MCH-32. They dramatically suppressed the B cell activation with lipopolysaccharide, T cell activation by mixed lymphocyte response, and primary T-dependent antibody response at a final concentration of 1 ${\mu}g$/ml. They also markedly suppressed the proliferation of lymphocytes induced by lipopolysaccharide, pokeweed mitogen, and concanavaline A at the same concentration. Their suppressive activities, which were comparable to those of cyclosporin A, suggested that they were potent and broad immunotoxic agents on the immune functions of murine lymphocytes.

• Journal of Periodontal and Implant Science
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• 제29권4호
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• pp.913-928
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• 1999

Since their discovery in 1949, cyanoacrylates interest many people as possibly being the ideal "Tissue glue". Several different forms of these compounds have been developed in attempt to reduce or eliminate tissue toxicity. Butyl-2-cyanoacrylate(Histoacryl) appears to be the most ideal material as it induces low tissue reactivity & toxicity. In this study, the histotoxic response of histoacryl, when used in a subcutaneous site was compared to a controls which was conventionally sutured. This response was greater than the control that showed no inflammation. However, these findings may not corre-late in actual clinical settings, because most patients tolerate mild degrees of infla-mmation well. Majority of the studies evaluating the histotoxicity of histoacryl have been per-formed when applied superficially & not below the skin surface. This is why further studies are required to evaluate the his-totoxicity of histoacryl when used in a sub-cutaneous site or mucosa.

• Tribology and Lubricants
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• 제28권6호
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• pp.321-327
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• 2012

Paraffin bio-based hydrotreated biodiesel(HBD) is originated from vegetable oil(the process can also be applied to animal fat) with the the chemical structure $C_nH_{2n+2}$. In the number of process of the oil or fat, the hydrogenation is significantly important to create a bio-based diesel fuel. This study is focused on lubricity characteristics of BTL diesel blends to use alternative diesel fuel in Korea. The BTL diesel are blended the different volume ratios (HBD 5(5 vol.% HBD - 95 vol.% diesel), HBD 10, HBD 20, HBD 30, HBD 40 and HBD 50. HBD with paraffin compounds showed a very high centane number, low sulfur content and free aromatic compound. Especially, the wear scar of HBD showed poor lubricity compared to automotive diesel due to the fuel composition, low sulfur content and free aromatic compound. Also, the lubricity specification of automotive diesel with different six HBD blends is within the limit by the Korean standards. Finally, HBD as an alternative diesel fuel is challengeable in transportation sector of Korea.

• 대한한방내과학회지
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• 제29권1호
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• pp.42-66
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• 2008

Aconiti Tuber is a traditional medicinal plant generally used in Oriental medicine therapy. In this study, we investigated the biochemical mechanisms of anti-proliferative effects by the methanol extract of Aconiti tuber (MEBJ) in Caki-1 human renal cell carcinoma cells. It was found that MEBJ could inhibit, in a dose-dependent manner, cell growth which was associated with apoptotic cell death such as formation of apoptotic bodies, DNA fragmentation and increased populations of apoptotic-sub G1 phase. Apoptosis of Caki-1 cells by MEBJ was associated with an up-regulation of pro-apoptotic Bax expression, and a down-regulation of anti-apoptotic Bcl-2 in a dose-dependent manner; however, the levels of IAP family were not affected. MEBJ treatment also induced the proteolytic activation of caspase-3 and -8, and a inhibition of poly(ADP-ribose) polymerase (PARP) and $PLC{\gamma}1$ protein. Furthermore, MEBJ treatment caused a dose-dependent inhibition of iNOS and cyclooxygenase-2 (Cox-2). Though further studies will be needed to identify the active compounds that confer the anti-cancer activity of MEBJ, the present findings provide important new insights into the possible molecular mechanisms of the apoptotic activity of MEBJ in cancer cells.

• Biomolecules & Therapeutics
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• 제8권2호
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• pp.147-152
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• 2000

The rodent uterotrophic assay is currently recommended as one of the primary in vivo assays far endocrine disrupting chemicals by the Organization for Economic Cooperation and Development (OECD) and Endocrine Disruptor Screening and Testing Advisory Committee (US EPA EDSTAC). Generally, this assay relies on the rapid increase in uterus and vagina weights when exposed to estrogenic compounds. Phthalate esters have been used extensively as a plasticizer in the manufacture of plastic products such as PVC films and medical devices. Recently, phthalate esters have been shown to induce endocrine system mediated responses. However, a flew studies have been conducted for the screening of their estrogenic activity. In this study the estrogenic activity of seven phthalate esters, butyl benzyl phthalate (BBP), di(2-ethylhexyl) phthalate (DEHP), di-n-butylphthalate (DBP), diethylphthalate (DEP), di-n-pentylphthalate (DPF), di-n-propylphthalate (DPrP) and dicyclohexylphthalate (DCHP), was examined in uterotrophic assay. Phthalate esters dissolved in corn oil were administered to ovariectomized (OVX) female Sprague-Dawley rats by sub-cutaneous injection for three consecutive days. fiats were sacrificed 24h after final treatment, and then uterus and vagina weights were deter mined. All phthalate esters tested in this assay did not change talc uterus and vagina weights at dosage levels up to 200 mg/kg/day treatment. These results demonstrated that phthalate esters did not exhibit estrogenic activity in vivo uterotrophic assay.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1998년도 Proceedings of UNESCO-internetwork Cooperative Regional Seminar and Workshop on Bioassay Guided Isolation of Bioactive Substances from Natural Products and Microbial Products
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• pp.134-134
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• 1998

The modulation of glycosidase activity by inhibitors is of great interest. Such compounds have been shown to be important tools in mechanistic studies on glycohydrolase as well as having promising therapeutic application. An ${\alpha}$-glucosidase inhibitor was isolated from culture filterates of Penicillium sp. The inhibitor was active against ${\alpha}$-glucosidase isolated from yeast and porcine small intestine. However, it showed no inhibition to Aspergillus ${\alpha}$-galactosidase, Escherichia coli ${\beta}$-galactosidase, and jack bean ${\alpha}$-mannosidase. The inhibitor was highly soluble in ether, methanol and chloroform. The inhibitor was purified using silica gel, Sephadex LH-20 column chromatography and reverse-phase HPLC. The inhibitory compound designated PA-7(IC$\sub$50/=35$\mu\textrm{g}$) was obtained as white powder. The structure of PA-7 was determined with spectroscopic data of EI-MS, FAB-MS, $^1$H, and $\^$13/C NMR. The inhibitor has a diketopiperazine moiety.

• 한국표면공학회지
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• 제51권1호
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• pp.34-39
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• 2018

Steel crucible used for molten Al has a problem of very limited lifetime because of the interaction between Fe and molten Al. This study was performed to improve the lifetime of steel crucible for molten Al by coating metallic Al and by further anodizing treatment to form thick and uniform anodic oxide films. The lifetime of the steel crucible was improved slightly by Al coating from 30 to 40 hours by metallic Al coating and largely to 120 hours by coating the surface with anodic oxide film. The improved lifetime was attributed to blocking of the reaction between Fe and molten Al with the help of anodic oxide layer with more than 20 um thickness on the crucible surface. The failure of the steel crucible arises from the formation of intermetallic compounds and pores at the steel/Al interface.

• Bulletin of the Korean Chemical Society
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• 제34권11호
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• pp.3253-3256
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• 2013

Lithium is a highly attractive material for high-energy-concentration batteries, since it has low weight and high potential. Rechargeable lithium-ion batteries (LIBs), which have the extremely high gravimetric and volumetric energy densities, are currently the most preferable power sources for future electric vehicles and various portable electronic devices. In order to improve the efficiency and lifetime, new electrode compounds for lithium intercalation or insertion have been investigated for rechargeable batteries. Solid-state nuclear magnetic resonance (NMR) is a very useful tool to investigate the structural changes in electrode materials in actual working lithium-ion batteries. To detect the in-situ microstructural changes of electrode and electrolyte materials, $^7Li-^{19}F$ double-resonance solid-state NMR probe with a static solenoidal coil for a 600-MHz narrow-bore magnet was designed, constructed, and tested successfully.