• Journal of Microbiology and Biotechnology
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• v.26 no.2
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• pp.226-232
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• 2016

Dihydrodipicolinate reductase is an enzyme that converts dihydrodipicolinate to tetrahydrodipicolinate using an NAD(P)H cofactor in L-lysine biosynthesis. To increase the understanding of the molecular mechanisms of lysine biosynthesis, we determined the crystal structure of dihydrodipicolinate reductase from Corynebacterium glutamicum (CgDapB). CgDapB functions as a tetramer, and each protomer is composed of two domains, an Nterminal domain and a C-terminal domain. The N-terminal domain mainly contributes to nucleotide binding, whereas the C-terminal domain is involved in substrate binding. We elucidated the mode of cofactor binding to CgDapB by determining the crystal structure of the enzyme in complex with NADP⁺ and found that CgDapB utilizes both NADH and NADPH as cofactors. Moreover, we determined the substrate binding mode of the enzyme based on the coordination mode of two sulfate ions in our structure. Compared with Mycobacterium tuberculosis DapB in complex with its cofactor and inhibitor, we propose that the domain movement for active site constitution occurs when both cofactor and substrate bind to the enzyme.

• Journal of the Korean Magnetics Society
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• v.16 no.1
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• pp.6-10
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• 2006

The sulphur spinel $FeCr_{2-x}M_xS_4$(M=Ga, In) have been studied with Mossbauer spectroscopy, x-ray diffraction (XRD), and vibrating sample magnetometer. The XRB patterns for samples $FeCr_{2-x}M_xS_4$(M=Ga, In: x=0.1, 0.3) reveal a single phase, which the Ga and In ions are partially occupied to the tetrahedral (A) site. The Neel temperature for the Ga substituted samples increases from 180 to 188 K, with increase from x=0.1 to 0.3. While, it decreases from 173 to 160 K, for the In substituted samples of the x=0.1 and 0.3, respectively. The Mossbauer spectra were collected from 4.2 K to room temperature. We have analyzed the Mossbauer spectra using eight Lorentzian lines fitting method for the $FeCr_{2-x}In_xS_4$(x=0.1) at 4.2 K, yielding the 1311owing results; $H_{hf}=146.0kOe,\;{\Delta}E_Q=1.88mm/s,\;\theta=36^{\circ},\;\phi=0^{\circ},\;\eta=0.6$, and R=1.9. The Ga ions enter into the both sites octahedral (B) and tetrahedral (A), simultaneously the same amounts of Fe ions migrate from the A to the B site, this result is an agreement with XRD results, too. The ${\Delta}E_Q$ of the A and B site in Mossbauer spectra of the samples $FeCr_{2-x}Ga_xS_4$(x=0.3) are 0.83 and 2.94mm/s, respectively. While they are 0.56 and 2.36mm/s for the $FeCr_{2-x}In_xS_4$(x=0.3). It is noticeable that the ${\Delta}E_Q$ for the Ga doped samples are larger than that of the corresponding In doped samples, in spite of the larger ionic radius for In ions. The bond lengths of Cr-S, for the Ga and In doped samples (x=0.3) are found to be 2.41 and $2.43\;{\AA}$, respectively. We interpret that the larger covalence effect from the smaller bond length induces a large asymmetric charge distribution. Finally, it gives a large quadrupole interaction.

• Journal of the Earthquake Engineering Society of Korea
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• v.14 no.1
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• pp.35-42
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• 2010

The best estimate Gutenberg-Richter b-value of the Korean Peninsula was estimated through an expert panel assigned to evaluate the currently available study results. The panel's assessment yielded that the Gutenberg-Richter b-value was relatively constant over the Korean Peninsula and was independent of seismic zones with an average value of 0.96. Also, the currently most reliable four seismotechtonic structural maps were produced. The effects on the seismic hazard were analyzed by applying the results to the Shinwuljin Units 1&2 NPP site. As a result, the mean hazard level at 0.2g was decreased by about 70-80% (on the order of 0.6-0.7), and the uncertainty band at 0.2g for the reliability band of 15%-85% was significantly reduced. It was proposed, for conservatism, to use b=0.95 over all seismic zones for seismic hazard analysis in the future.

• Journal of the Korean Magnetics Society
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• v.18 no.1
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• pp.19-23
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• 2008

The mixed ferrite $V_xFe_{3-x}O_4$(x=0.0, 0.15, 0.5, 1.0) thin films were prepared by sol-gel method. Their crystallographic and magnetic hyperfine properties have been studied using X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS) and conversion electron $M\"{o}ssbauer$ spectroscopy(CEMS). The crystal structure is found to be cubic spinel throughout the series($x{\leq}1.0$), and the lattice parameter $a_0$ increases linearly with increasing V content. XRD, XSP and CEMS indicate that $V^{3+}$ substitution for $Fe^{3+}$ in B-site is superior to $V^{2+}$ substitution for $Fe^{2+}$ in B-site. It is noticeable that both quadrupole shift and hyperfine field decreases with increasing V composition, suggesting the change of local symmetry and accompanying line-broadening. The line-broadening on CEMS spectra can be explained by the distribution of magnetic hyperfine fields.

• Geophysics and Geophysical Exploration
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• v.10 no.3
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• pp.183-190
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• 2007

The site effects of seismic stations were evaluated by conducting a simultaneous inversion of the stochastic point-source ground-motion model (STGM model; Boore, 2003) parameters based on the accumulated dataset of horizontal shear-wave Fourier spectra. A model parameter $K_0$ and frequency-dependent site amplification function A(f) were used to express the site effects. Once after a H/V ratio of the Fourier spectra was used as an initial estimate of A(f) for the inversion, the final A(f) which is considered to be the result of combined effect of the crustal amplification and loca lsite effects was calculated by averaging the log residuals at the site from the inversion and adding the mean log residual to the H/V ratio. The seismic stations were classified into five classes according to $logA_{1-10}^{max}$(f), the maximum level of the site amplification function in the range of 1 Hz < f < 10 Hz, i.e., A: $logA_{1-10}^{max}$(f) < 0.2, B: 0.2 $\leq$ $logA_{1-10}^{max}$(f) < 0.4, C: 0.4 $\leq$ $logA_{1-10}^{max}$(f) < 0.6, D: 0.6 $\leq$ $logA_{1-10}^{max}$(f) < 0.8, E: 0.8 $\leq$ $logA_{1-10}^{max}$(f). Implication of the classified result was supported by observing a shift of the dominant frequency of average A(f) for each classified stations as the class changes. Change of site classes after moving seismic stations to a better site condition was successfully described by the result of the station classification. In addition, the observed PGA (Peak Ground Acceleration)-values for two recent moderate earthquakes were well classified according to the proposed station classes.

• Journal of Microbiology and Biotechnology
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• v.18 no.3
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• pp.591-599
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• 2008

A murine model immunized by systemic and mucosal delivery of plasmid DNA vaccine expressing glycoprotein B (pCIgB) of pseudorabies virus (PrV) was used to evaluate both the nature of the induced immunity and protection against a virulent virus. With regard to systemic delivery, the intramuscular (i.m.) immunization with pCIgB induced strong PrV-specific IgG responses in serum but was inefficient in generating a mucosal IgA response. Mucosal delivery through intranasal (i.n.) immunization of pCIgB induced both systemic and mucosal immunity at the distal mucosal site. However, the levels of systemic immunity induced by i.n. immunization were less than those induced by i.m. immunization. Moreover, i.n. genetic transfer of pCIgB appeared to induce Th2-biased immunity compared with systemic delivery, as judged by the ratio of PrV-specific IgG isotypes and Th1- and Th2-type cytokines produced by stimulated T cells. Moreover, the immunity induced by i.n. immunization did not provide effective protection against i.n. challenge of a virulent PrV strain, whereas i.m. immunization produced resistance to viral infection. Therefore, although i.n. immunization was a useful route for inducing mucosal immunity at the virus entry site, i.n. immunization did not provide effective protection against the lethal infection of PrV.

• Korean Journal of Ecology and Environment
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• v.43 no.2
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• pp.255-262
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• 2010

This study was conducted at 5 sites of Bocheong Stream basin in May and September 2009 for the evaluate of fish assemblage and chemical water quality. For the study, the models of Index of Biological Integrity (IBI) and Qualitative Habitat Evaluation Index (QHEI) were modified as 8 and 11 metric attributes, respectively. We also analyzed patterns of chemical water quality at the sampling site over the period of 2005~2009, using the water chemistry dataset, obtained from the Ministry of Environment, Korea. The survey showed that total sampled fishes were 34 species and the most dominant species was Zacco platypus (24.3%). In Bocheong Stream basin, values of IBI averaged 28 (n=5), which is judged as a "Good". IBI score at B1, B4 and B5 indicating a "Good" condition whereas, B2 and B3 were as 21 and 22, indicating "Fair" condition, respectively. QHEI was 152 (n=5), judged as "Fair" habitat condition. Values of BOD and COD averaged 1.0 $mgL^{-1}$ (scope: 0.3~4.0 $mgL^{-1}$) and 2.3 $mgL^{-1}$ (scope: 0.3~18.7 $mgL^{-1}$), respectively. Total nitrogen (TN), total phosphorus (TP) and suspended solid (SS) were distinct spatial variation. Based on the IBI, QHEI and chemical water quality dataset, ecological health of Bocheong Stream basin was evaluated that generally good.

• Korean Journal of Agricultural Science
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• v.38 no.1
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• pp.51-63
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• 2011

BoLA (bovine leukocyte antigens) have been known as gene complex related with bovine diseases and immunological traits. This study was conducted to find out the characteristics of BoLA-DRB3 gene related to mastitis and BL(bovine leukocyte) from 280 cattle [193 animals of Holstein cattle and 87 animals of Hanwoo]. As a result, five PCR-RFLP types (b, d, e, f and g) using HaeIII restriction enzyme, three BstYI restriction patterns (b, d and e) and eight RsaI restriction types(b, d, f, I, j, n, o and w) were identified. Moreover, we identified new d' type ($197{\rightarrow}175$/22), having one more cutting site by BstYI enzyme than d type allele and n' type ($180{\rightarrow}169$/11) having one more cutting site by RsaI enzyme than n allele was additionally identified. Next, we identified 53 SNPs in BoLA-DRB3 exon2 from 280 cattle. SNP frequency and heterozygosity of Holstein and Hanwoo were investigated in all the SNP genotype. These results might be based on research for identifying marker associated with bovine diseases.

• The Korean Journal of Food And Nutrition
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• v.9 no.4
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• pp.459-465
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• 1996

Bacillus thuringiensis serovar. darmstadiensis produced bipyramidal endo-toxin. The toxin protein was purified by Renografin-76 step gradient centrifugation and investigated by electron microscope. Analysis of total plasmid DNA patterns showed that four different size of plasmids existed in wild type B. thuringiensis serovar. darmstadiensis. Total plasmids DNA was isolated and transformed into pst I site of pBR322 cloning vector. Ten clones containing crystal toxin gene were forst screened colony hybridization by using PUYBT 9044 probe ontained B. thuringiensis kurskaki HD 1 toxin gene. Cloned-DNA was digested with EcoR1 and HindIII and transformed to pIBI30 sequencing vector. Finally, 2.6kb and 3.6kb size fragments contatined toxin-gene were cloned with restriction analysis.

• Journal of Korean Society of Rural Planning
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• v.16 no.3
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• pp.87-101
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• 2010

This research has a significance on providing basic material of landscape ecological planning and open space planning of the future site by selecting Sinseo innovative city area, large residential land development district in rural area, by classifying biotope types and implementing recreational value assessment in the level of area. First of all, as a result of classification of biotope types in research site, total 11 biotope type groups including stream biotope and its subordinate 51 biotope types. Also, as a result of the first value assessment of classified biotopes, there are total 5 types such as vegetation-full natural river, fallow ground in I grade. In addition, it is analyzed that grade II have 18 types, III are 10, IV are 12, the least valuable V are 6. Especially, grassland biotope(GD) was classified into grade II, which is one grade raised, because it is analyzed that it has high value in terms of normal access and availability although it was assessed as grade ill in terms of natural experience quality. Lastly, as a result of the second assessment, special areas for natural experience and recreation(1a, 1b) are 15, areas for natural experience and recreation(2a, 2b, 2c) are 47. Especially, the 52th drawing mark space was grade II in the first assessment but its value grade was upgraded because of its high value in terms of use evidence, size of the area, accessibility with housing area, history and cultural character and so on.