• Journal of Plant Biology
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• v.34 no.4
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• pp.331-339
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• 1991

To elucidate the regulatory mechanism of virE operon from vir regions (virA, virB, virC, virD, virG, virE) of pTiA6 which have been known to be essential for efficient crown gall tumorigenesis in plants, the activity of the truncated virE, promoter was analyzed. pSM358cd, a recombinant plasmid in which virE :: Tn3-HoHo1 (Tn3-promoterless lacZ) was cloned into SalI site of pVK102, was digested with SalI, and virE :: Tn3-HoHo1 was seperated from pVK102. To construct the truncted virE recombinant plasmids (pJS031, pJS051, pJS102, pJS201, pJS301), 5'-end of vireE promoter was deleted with BAL31 and cloned into pVK102 and then transferred into a. tumefaciens A348(pTiA6). According to the activity of the truncated virE promoter in recombinant plasmids, they were classified into two groups, pJS031, pJS051, pJS101 and pJS201 belong to a functional group and pJS301 is a non-functional. The size of deleted nucleotides of pJS201 and pJS301 seemed to be about 130 nucleotides and about 250 nucleotides from 5'-end of virE promoter, respectively. Hence it was thought that the essential site of the virE promoter was located between about 130th nucleotide and 250th nucleotide from 5'-end of the virE promoter.

• Electric Engineers Magazine
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• v.228 no.8
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• pp.52-57
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• 2001

Presently the Korean grounding system uses TN system, multi-grounding method with IT independent grounding method. Nevertheless TN system can't exist with TT system in the technological terms. If they coexist, it causes ground-fault circuit not to operate, and brings about different electrical potential rise by customer system. It brings about serious problems for safety. This paper aims for improving method of grounding system based on the technical analysis on instances in foreign countries and Korea. Almost standards and construction manner were apt to be internationalized after WTO/TBT agreement was concluded. The internal grounding systems should meet the international criteria and reliability for safety, and be provided with technologically impeccable standards.

• Microbiology and Biotechnology Letters
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• v.23 no.3
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• pp.275-281
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• 1995

From the plasmid pYA300 carring a CMCase of Rhizobium fredii USDA193 plasmid was subcloned into pBluescript II KS(+)/pBluescript II SK(+) vectors and designated pYA500 and pYA600, respectively. Escherchia coli cells transformed with pYA500 porduced the CMCase more than with pYA600. The orientation of the cloned fragment in pBluescript vector had the effect on gene expression in E. coli background. When the 1.7 kb CMCase gene fragment of R. fredii USDA193 was hybridized to EcoRI-digested total DNA from R. meliloti and R. fredii USDA 191 the unique bands hybridized respectively, indicating that some genetic diversity exists in the EcoRI restriction enzyme site for CMCase gene in Rhizobium strains. The optimum pH of enzyme activity was 7 and the optimum temperature of that was nearly 37$\circ$C. The cellulase-minus derivatives of pYA500 were constructed by Tn5 insertional mutation. Among 6000 transconjugants, two mutant plasmids (designated pYA500::Tn5a and pYA500::Tn5b) were detected from the cellulase- negative transconjugants. The product of CMCase gene was analyzed by one dimensional SDS- PAGE of the cell extracts. About 45 kDa protein was considered to be a product of CMCase gene.

• Environmental Engineering Research
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• v.23 no.4
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• pp.364-373
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• 2018

The present study assessed the efficient removal of nutrients and Chlorophyll-a (Chl-a) by using methyl esterified sericite (MES) and pine needle extracts (PNE), a low cost and abundant green hybrid material from nature. For this purpose, the optimal conditions were investigated, such as the pH, temperature, MES and PNE ratio, and MES-PNE dose. In addition, a Microcystis aeruginosa control using MES-PNE was also analyzed with various inhibition models. The removal of the nutrient and Chl-a onto MES-PNE was optimized for over 95% removal as follows: 2-2.5 for the MES-PNE ratio, 7-8 pH and a $22-25^{\circ}C$ temperature. In this respect, approximately 1.52-2.20 g/L of MES-PNE was required to remove each 1 g of dry weight/L of Chl-a. Total phosphorus (TP) has a greater influence on the increase in Chl-a than total nitrogen (TN) according to the correlation between TN, TP and Chl-a. Moreover, the Luong model was the best model for fitting the biodegradation kinetics data from Chl-a on MES-PNE from lake water. The novel hybrid material MES-PNE was very effective at removing TN, TP and Chl-a from the lake and can be applied in the field.

• Economic and Environmental Geology
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• v.43 no.1
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• pp.1-12
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• 2010

Geochemical approaches on the two recovered piston cores were performed to understand the characteristics of organic matters and the influence of the sea level variation of the East Sea in the Hupo Basin since the Holocene. The analyzing results on organic components (TOC and TN), and isotopic compositions of organic matters showed the variation to core locations and sampling depths. In core 08HZP-01, their values were gradually changed with depth from 4 mbsf to seafloor. However, rapid variation was observed at the boundary of 4.71 mbsf (meter below seafloor) in core 08HZP-03. Based on TOC/TN, $\delta^{13}C_{org}$ and $\delta^{15}N_{org}$, the origin of organic matters in the Hupo Basin can be divided into three groups; 1) predominant marine algae, 2) $C_3$ land plant, and 3) mixture of $C_3$ land plant and marine/freshwater algae. It is likely that the vertical and spatial variations of organic and isotopic compositions reflect the shifts in sedimentary environment (including sediment transportation) by ocean currents and sea-level changes and others during the Holocene period.

• Microbiology and Biotechnology Letters
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• v.19 no.1
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• pp.31-36
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• 1991

A 7.5 kilobases hybrid plasmid, designated as pCE1301, was constructed by combining Eschurichia cwli plasmid pBELl which carries the kanamycin resistance gene of Tn5 with a cryptic plasmid, pSRl of Corynebacterium glutamicum. pCE1301 was transformed C. glutaicum by PEG-mediated protoplast method and its transformation efficiency was about $3.0\times 10^3$ transformants per $\mu g$ of the hybrid plasmid DNA. The physical map reveals that pCE1301 has single restriction sites for SalI and EcoRl, respectively. 'The kanamycin resistance of pCE1301 was stably maintained in C. glutamicum up to 25 generations and any segregation was not detected. pCI31301 was also introduced into Brevibacterium flavum and E coil, and replicated in those strains. pCE1301 was proved to be useiul in cloning the homoscrine dehydrogenase gene from C. glutamicum.

• Journal of Microbiology and Biotechnology
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• v.14 no.2
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• pp.302-311
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• 2004

Comamonas testosteroni (formerly Pseudomonas sp.) NCIMB 10643 can grow on biphenyl and alkylbenzenes $(C_2-C_7)$ via 3-substituted catechols. Thus, to identify the genes encoding the degradation, transposon-mutagenesis was carried out using pAG408, a promoter-probe mini-transposon with a green fluorescent protein (GFP), as a reporter. A mutant, NT-1, which was unable to grow on alkylbenzenes and biphenyl, accumulated catechols and exhibited an enhanced expression of GFP upon exposure to these substrates, indicating that the gfp had been inserted in a gene encoding a broad substrate range catechol 2,3-dioxygenase. The genes (2,826 bp) flanking the gfp cloned from an SphI-digested fragment contained three complete open reading frames that were designated bphCDorfl. The deduced amino acid sequences of bphCDorfl were identical to 2,3-dihydroxybiphenyl 1,2-dioxygenase (BphC), 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoate hydrolase (BphD), and OrfI, respectively, that are all involved in the degradation of biphenyl/4-chlorobiphenyl (bph) by Ralstonia oxalatica A5. The deduced amino acid sequence of the orfl revealed a similarity to those of outer membrane proteins belonging to the OmpW family. The introduction of the bphCDorfl genes enabled the NT-l mutant to grow on aromatic hydrocarbons. In addition, PCR analysis indicated that the DNA sequence and gene organization of the bph operon were closely related to those in the bph operon from Tn4371 identified in strain A5. Furthermore, strain A5 was also able to grow on a similar set of alkylbenzenes as strain NCIMB 10643, demonstrating that, among the identified aromatic hydrocarbon degradation pathways, the bph degradation pathway related to Tn4371 was the most versatile in catabolizing a variety of aromatic hydrocarbons of mono- and bicyclic benzenes.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.193-193
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• 2011

국제기구인 정부간 기후변화협의체(Intergovernmental Panel on Climate Change, 이하 IPCC)에서는 기후변화가 기온 상승에 따른 증발산량의 증가, 강수량 및 유출량의 시공간적 분포의 변동 등을 초래하여 수자원의 효율적 관리 및 안정적인 공급에 어려움을 증대시킬 것으로 전망하였다. 또한 IPCC 4차 보고서에 따르면 21세기말 지구의 평균기온은 현재보다 최대 $6.3^{\circ}C$정도 더 상승할 것으로 전망하였다. 전구평균기온이 $3.0^{\circ}C$ 증가할 경우 아시아에서만 연간 700만 명이상이 홍수피해 위기에 직면할 것으로 예상되고 있다. 국내의 경우 기온은 전구평균기온에 비해 2배 이상 높은 $1.5^{\circ}C$ 정도 상승하였으며, 최근 50년간의 강우일수는 감소한 반면 일강수량이 80mm 이상인 호우일수의 발생빈도는 증가되고 있다고 보고되었다. 또한 최근의 물수지 해석과 관련하여 거시적인 관점에서 기온 및 강수량 증가에 따른 물순환 과정을 모의하고, 농업용수, 댐건설, 도시화, 토지이용의 변화 등 인위적인 환경 변화 및 기후변화에 따른 유출량의 변화를 정량화하려는 연구들이 수행되고 있다(한국건설기술원, 2007). 이를 위하여 단기적이 아니라 장기적인 측면에서 유출분석을 할 필요가 있으나, 현재까지 보유하고 있는 실측 자료의 한계 및 이러한 조사를 위해 요구되는 시간 및 비용의 한계 때문에, 유출해석 모형을 주로 이용하고 있다. 본 연구에서는 장래 건설예정인 미계측 호소의 유량과 수질을 모의하기 위하여 하천, 하구, 호소 및 해역에 고루 적용할 수 있는 3차원 수리 동력학적인 모델인 EFDC 모형과 시간의 변화에 따른 수질을 모의하는데 가장 널리 이용하는 WASP 모형을 도입하였다. 향후, 내성천의 영주댐 건설과 같은 큰 변화가 발생하였을 기후 변화의 영향을 파악하기 위하여 EFDC와 WASP모형을 이용하여 대상유역에 대한 유출량과 수온의 변화를 통하여 A2, B1 기후변화 시나리오별로 2020년, 2050년, 2080년의 수질(BOD, TN, TP)변화를 분석하여 보았다. 연구의 결과는 다음과 같이 나타났다. EFDC 및 WASP 모형의 연계를 통한 기후 변화 시나리오에 따른 미래의 저수지 수질예측 모의를 수행한 결과, BOD, TN, TP 등 수질농도 변화는 2020년에서 2080년도로 갈수록 BOD, TN 다소 증가하는 경향을 나타내었고, TP농도는 감소하였다. 시나리오별 변화 특성은 TN, TP 농도는 A2 시나리오가 다소 높고, BOD 농도는 B1 시나리오가 A2보다 높은 것으로 나타났다. EFDC와 WASP을 이용하여 미계측 호소에 대한 기후변화 시나리오별로 적용하여 수질변화를 예측하여 보았는데, 향후 기후변화에 따른 기온, 유량변화와 수질 항목간의 상간관계 정립 및 수질 모의의 불확실성 등에 대한 추가 연구가 필요할 것으로 판단된다.

• Molecules and Cells
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• v.37 no.2
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• pp.118-125
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• 2014

Osteosarcoma is the most common primary malignant bone tumor with a very poor prognosis. Treating osteosarcoma remains a challenge due to its high transitivity. Tenascin-C, with large molecular weight variants including different combinations of its alternative spliced FNIII repeats, is specifically over expressed in tumor tissues. This study examined the expression of Tenascin-C FNIIIA1 in osteosarcoma tissues, and estimated the effect of mechanical stimulation on A1 expression in MG-63 cells. Through immunohistochemical analysis, we found that the A1 protein was expressed at a higher level in osteosarcoma tissues than in adjacent normal tissues. By cell migration assay, we observed that there was a significant correlation between A1 expression and MG-63 cell migration. The relation is that Tenascin-C FNIIIA1 can promote MG-63 cell migration. According to our further study into the effect of mechanical stimulation on A1 expression in MG-63 cells, the mRNA and protein levels of A1 were significantly up-regulated under mechanical stress with the mTOR molecule proving indispensable. Meanwhile, 4E-BP1 and S6K1 (downstream molecule of mTOR) are necessary for A1 normal expression in MG-63 cells whether or not mechanical stress has been encountered. We found that Tenascin-C FNIIIA1 is over-expressed in osteosar-coma tissues and can promote MG-63 cell migration. Furthermore, mechanical stress can facilitate MG-63 cell migration though facilitating A1 overexpression with the necessary molecules (mTOR, 4E-BP1 and S6K1). In con-clusion, high expression of A1 may promote the meta-stasis of osteosarcoma by facilitating MG-63 cell migration. Tenascin-C FNIIIA1 could be used as an indicator in metastatic osteosarcoma patients.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.2
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• pp.211-215
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• 2001

Urea as a silage additive increases crude protein but reduces fermentation quality of silage by increasing pH and enhancing clostridial bacteria growth, especially in low sugar forages. Glucose and formic acid might be expected to compensate these defects caused by urea addition to grass silage. Thus, in this experiment urea formic acid or urea with glucose was applied to improve N content and the quality of napiergrass (Pennisetum purpureum Schumach.) silage. The first growth of napiergrass was harvested at 85 days of age and about 700 g of the grass was ensiled in laboratory silos (1.0 liter polyethylene containers) for 2, 7, 14, and 30 days at room temperature ($28^{\circ}C$). The treatments were no additives (control), urea, urea+glucose or urea+formic acid. Urea was added before ensiling at 0.5% of fresh weight of napiergrass and glucose and formic acid were added at 1% of fresh weight, respectively. After opening the silo, pH, dry matter content (DM), contents on DM basis of total N (TN), volatile basic nitrogen (VBN), lactic acid (LA), acetic acid (AA) and butyric acid (BA) were determined. The control at 30 days of fermentation showed 5.89 for pH with 13.8% for VBN/TN and 1.51% for AA. The addition of urea increased TN by about 1.5% units but decreased the fermentation quality by increasing pH from 5.89 to 6.86, increasing VBN/TN from 13.8% to 24.63%, increasing BA from 0.02% to 0.56%, and decreasing LA from 1.03% to 0.02%. Glucose addition with urea significantly decreased VBN/TN from 13.8% to 4.44% by reducing pH from 6.86 to 4.83 because of higher production of LA (2.62%). Adding urea and formic acid resulted in a more pronounced depression of VBN/TN and fermentation than the addition of urea and glucose. This study suggested that the combination of 1% glucose or 1% formic acid with 0.5% urea will improve nutritive value and fermentation quality of napiergrass silage.