• Journal of the Korean Society of Environmental Restoration Technology
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• v.8 no.5
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• pp.10-18
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• 2005

The research was carried out to define the morphological and growth characteristics of Poa pratensis L.(Kentucky bluegrass) 'Sewon' in native to Korea. Poa pratensis 'Sewon' was collected at the terrace land on the river in Guiman-ri, Cheongcheon-myeon, Goesan-gun, Chungcheongbuk-do on May 5, 1995. The collected Poa pratensis 'Sewon' was grown under non-mowing naturally growing condition. The morphological characteristics of Poa pratensis 'Sewon' are as follows. : The height of plant was 21.6cm but was increased to 33cm at the flowering time. The height of first node from the base was 5.0cm and the length and width of leaf were 9.6cm and 4.1cm, respectively. The length of inflorecences was 37.8cm and the length of a spike was 7.3cm. Based on these morphological characteristics, Poa pratensis 'Sewon' was defined to dwarf~medium and coarse texture type Kennturky bluegrass. 1 to 9 scale of visual quality, visual color and visual density were measured. Poa pratensis 'Sewon' showed best turf qualities among native Kentucky bluegrasses. In spring and fall growing season, Poa pratensis 'Sewon' were measured to be excellent performances for turf qulities similar to foreign excellent quality cultivars such as Midnight, Nuglade and Brilliant Kentucky bluegrasses. But turf quality of Poa pratensis 'Sewon' decreased by plant disease according to temperature increase in summe compared to foreign excellent quality cultivars. So, Poa pratensis 'Sewon' should be improved of disease tolerent quality by incessant breeding work in order to compete foreign excellent quality cultivars.

• Journal of Soil and Groundwater Environment
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• v.19 no.2
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• pp.16-24
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• 2014

To test the potential effects of extracellular electron shuttles (EES) on the rate and extent of heavy metal release from contaminated soils during microbial iron reduction, we created anaerobic batch systems with anthraquinone-2,6-disulfonate (AQDS) as a surrogate of EES, and with contaminated soils as mixed iron (hydr)oxides and microbial sources. Two types of soils were tested: Zn-contaminated soil A and As/Pb-contaminated soil B. In soil A, the rate of iron reduction was fastest in the presence of AQDS and > 3500 mg/L of total Fe(II) was produced within 2 d. This suggests that indigenous microorganisms can utilize AQDS as EES to stimulate iron reduction. In the incubations with soil B, the rate and extent of iron reduction did not increase in the presence of AQDS likely because of the low pH (< 5.5). In addition, less than 2000 mg/L of total Fe(II) was produced in soil B within 52 d suggesting that iron reduction by subsurface microorganisms in soil B was not as effective as that in soil A. Relatively high amount of As (~500 mg/L) was released to the aqueous phase during microbial iron reduction in soil B. The release of As might be due to the reduction of As-associated iron (hydr)oxides and/or direct enzymatic reduction of As(V) to As(III) by As-reducing microorganisms. However, given that Pb in liquid phase was < 0.3 mg/L for the entire experiment, the microbial reduction As(V) to As(III) by As-reducing microorganisms has most likely occurred in this system. This study suggests that heavy metal release from contaminated soils can be strongly controlled by subsurface microorganisms, soil pH, presence of EES, and/or nature of heavy metals.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.7
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• pp.960-965
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• 2010

To develop Corni Fructus as a cancer preventive food material, the in vitro cytotoxicities and in vivo antitumor activities of various concentrations of 80% Corni Fructus ethanol extract (CFEE) were investigated using sarcoma-180 cancer cell. Viability was decreased and cell death rate was increased in both dose- and time-dependent manners in cells treated with CFEE at 10, 100, 300, and $500\;{\mu}g/mL$ concentrations for 24, 48, and 72 hr. Proliferation was also inhibited more than 60% in cells treated with CFEE at the $100\;{\mu}g/mL$ concentration for 48 hr. In addition, the morphology of cells treated with CFEE at the 100 and $500\;{\mu}g/mL$ concentrations was distorted with shrunken cell masses and lower cell numbers compared to the control cells. In the cells treated with CFEE, the formation of apoptotic bodies and nuclear condensation were observed in dose dependent manners. CFEE also increased DNA fragmentation values at the 100 and $500\;{\mu}g/mL$ concentrations. The apoptosis induced by CFEE was connected to the proteolytic activation of caspase-3. When CFEE was administered at 100 and 300 mg/kg, ip, for 7 consecutive days in mice inoculated with sarcoma-180 cancer cell, the life span of the mice was found to be longer than that of the control mice that did not receive the extract. These results suggest that Corni Fructus may be used as a potential cancer preventive food material.

• BMB Reports
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• v.32 no.4
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• pp.326-330
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• 1999

An aspartase purified from Hafnia alvei was inactivated by diethylpyrocarbonate (DEP) in a pseudo-first-order inactivation. The first-order plot was biphasic. The inactivation process was not saturable and the second order rate constant was $1.3\;M^{-1}s^{-1}$. The inactivated aspartase was reactivated with NH₂OH. The difference absorption spectrum of DEP-inactivated vs native enzyme preparations revealed a marked peak around 242 nm. The pH dependence of the inactivation rate suggests that an amino acid residue having a pK value of 7.2 was involved in the inactivation. L-aspartate, fumarate (substrates), and chloride ion (inhibitor) protected the enzyme against inactivation, indicating that histidine residues for the enzyme activity are located at the active site of this aspartase. Inspection of the presence and absence of $Cl^-$ ion demonstrated that the number of essential histidine residues is less than two. Thus, one or two histidines are in or near the aspartate binding site and participate in an essential step of the catalytic reaction.

• Natural Product Sciences
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• v.19 no.2
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• pp.145-149
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• 2013

A simple reversed phase HPLC method was established for quantitative determination of liquiritigenin (1), genistein (2), isoliquiritigenin (3), and 7-hydroxyflavanone (4) from stems of Spatholobus suberectus Dunn (Leguminosae) using a binary gradient of $H_2O$ and MeOH as a mobile phase with UV detection at 280 nm. All calibration curves showed good linear regression ($r^2$ > 0.998) within test ranges. The detection limits of the four compounds were $0.43{\sim}1.63{\mu}g/mL$. The contents of four flavonoids (1 - 4) from the stem of S. suberectus were 6.54 mg/g, 1.66 mg/g, 6.65 mg/g, and 1.93 mg/g, respectively.

• Microbiology and Biotechnology Letters
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• v.23 no.6
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• pp.717-722
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• 1995

Using a flocculating Saccharomyes cerevisiae CA-1, an air-lift reactor equipped with a modified settler was used for ethanol fermentation. The effects of conditions such as aeration rate, initial glucose concentration, and dilution rate were studied using the air-lift reactor. In batch fermentation, optimum aeration rate was 0.5 vvm. In continuous fermentation, aeration rate and initial pH were fixed 0.5 vvm and 4.5, substrate concentration and dillution rate were changed 10-15% and 0.1-1.3. The maximum ethanol productivity was shown to be 20.4 g/l$\cdot $h in 10% glucose and 0.7 h$^{-1}$ dilution rate., and optimum operation condition considering the ethanol productivity and glucose utilization ratio was 0.5 h$^{-1}$ dilution rate in 10% glucose concentration.

• Journal of Information Technology Services
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• v.7 no.3
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• pp.47-70
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• 2008

File sharing technology is the most popular methodology through which consumers gain music from online. However, music file sharing and free downloads of music have caused terrible recession of traditional music industry. The purpose of this paper is to develop the underlying theory for understanding the acceptance of music file sharing technology and empirically test our theoretical model. We develop extended TAM model and explore the influencing factors on the user acceptance of music file sharing technology. Our study delivers a better understanding on consumers’ attitudes towards music downloads. By understanding the fundamental characteristics of technology that makes consumers enthusiastic, traditional music industry will gain managerial implications.

• Journal of Microbiology and Biotechnology
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• v.17 no.4
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• pp.681-684
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• 2007

An immunoassay method was developed to quantitatively detect phosphinothricin-N-acetyltransferase (PAT) encoded by the Bialaphos resistance (bar) gene in genetically modified (GM) pepper. The histidine-tagged PAT was overexpressed in Escherichia coli M15 (pQE3l-bar) and efficiently purified by $Ni^{2+}$ affinity chromatography. A developed sandwich enzyme-linked immunosorbent assay (S-ELISA) method (detection limit: $0.01{\mu}g/ml$) was 100-fold more sensitive than a competitive indirect ELISA (CI-ELISA) method or Western blot analysis in detecting the recombinant PAT. In real sample tests, PAT in genetically modified herbicide-tolerant (GMHT) peppers was successfully quantified [$4.9{\pm}0.4{\mu}g/g$ of sample (n=6)] by the S-ELISA method. The S-ELISA method developed here could be applied to other GMHT crops and vegetables producing PAT.

• Bulletin of the Korean Chemical Society
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• v.15 no.10
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• pp.845-849
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• 1994

Tetracarbonylhydridoferrate, $HFe(CO)^-_4$, generated by the reaction of $Fe(CO)_5$ with alkaline solution, is a good reducing agent for mono-dehalogenation of gem-dihalocyclopropanes. It also acts as a good reducing catalyst under phase transfer reaction conditions. 1,1-Dibromo-2-phenylcyclopropane and 1,1-dichloro-2-phenylcyclopropane were reduced to the corresponding mono-dehalogenated products in excellent yields. Thermodynamically stable trans-l-bromo-2-phenyl cyclopropane was formed as the major product over the cis-isomer, trans/cis=3/2. The 1-bromo-2-phenyl cyclopropane radical intermediate was formed by single electron transfer from $HFe(CO)^-_4$. Dissociation of bromide anion, followed abstraction of hydrogen radical from alcoholic solvent would lead to the formation of the stable trans-isomer. The further mechanistic aspects were discussed.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.108.3-109
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• 2003

In the present study, we investigated the antitumor effects of Ginsenoside Rh2 and $\beta$-glucan using an experimental metastatic mouse model intravenously injected with B 16 melanoma F10 cells. Oral administration to various concentration of $\beta$-glucan (50mg/kg, l00mg/kg and 200mg/kg) dose-dependently reduced the lung-metastatic potential of metastatic BI6 melanoma F10 cells in syngenic mice. At same dose, Ginsenoside Rh2(50mg/kg) has more antitumor effect than $\beta$-glucan(50mg/kg). (omitted)