• 한국미생물·생명공학회지
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• 제20권4호
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• pp.483-490
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• 1992

수계 환경에서 일어나는 유전자의 전이행방을 이해하기 위하여, conjugation에 의하여 전이되는 kanamycin 내성 ($Km^r$) 유전자에 대하여 DNA probe를 이용하여 Southern hybridization 방법으로 추적하였다. 자연계로부터 분리한 $Km^r$ 세균과 $Km^r$ 유전자를 유전자 조작기법으로 변형시킨 GMM 균주들을 donor로 하여 conjugation을 했을 때, $Km^r$ 유전자는 자연계 분리 균주에서보다 수질환경에 관계없이 10~00배 잘 전이되었다. LB 배지에서 GMM 균주의 $Km^r$ 유전자가 전이된 conjugant에서는 새로 생성되는 plasmid가 많이 나타났고 AW와 FW에서는 conjugation 시간에 따라 plasmid의 재배열 현상이 다양하였다. LB에서 얻은 conjugant들의 plasmid에 대하여 $Km^r$ DNA probe로 Southern analysis를 한 결과, plasmid의 재배열이 다양함에도 불구하고 conjugant들의 $Km^r$ plasmid는 donor에서와 같은 위치에서 hybridization signal이 나타났다. 그러나 AW에서 50시간 conjugation시켰을 때 DKI의 pDK101과 DKC601의 pDT529, 그리고 AW에서 30시간 conjugation 시켰을 때 DKC600의 pDK101은 전혀 나타나지 않고, 소실되었다. 또 전이된 $Km^r$ plasmid의 크기는 AW와 FW의 수질에 따라 약간 변화되어 나타났다. 그러므로 DNA probe에 의한 Southern hybridization 방법은 수질환경에서 특정 유전자의 전이행방을 추적하는데 매우 유용하다고 판단된다.

• 대한화학회지
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• 제23권5호
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• pp.277-285
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• 1979

비선형 Hammett 관계를 고찰하기 위해서 $XC_6H_4CH_2Cl\;(X=H,\;p=CH_3,\;p-NH_2,\;p-NO_2)$와 benzyl radical, cation, anion에 대해서 CNDO/2 계산을 행하였다. 이로부터 얻은 주요 결론은 다음과 같다. 1. 염화벤질은 C-Cl 결합과 고리의 $\pi$-system 간의 ${\sigma}-{\pi}$ conjugation으로 기인되는 borderline 성질을 나타내고 있다. 2. Mutual conjugation의 정도는 $\pi$-charge와 bond alternation, 그리고 interfrontier level separation narrowing 효과로 확인된다. 3. 전자공여 파라치환체는 벤질탄소의 HOMO AO 계수를 감소시키는 반면, 전자흡인 파라치환체는 벤질탄소의 LUMO AO 계수를 감소시킨다.

• Journal of Microbiology and Biotechnology
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• 제10권4호
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• pp.535-538
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• 2000

Streptomyces lavendulae FRI-5 produces the ${\gamma}$-butyrolactone autoregulator IM-2, which is required for nucleoside antibiotic producetion. We have developed a system for introducing DNA into S. lavendule FRI-5 via conjugal transfer from Esherichia cole. Conditions were established for conjugation of the oriT-and attP-containing plasmid pSET152 from E. coli ET12567 (pUZ8002) to FRI-5. Conjugation resulted in integration of the plasmid at the chromosomal C31 attB site. The frequency of intergeneric conjugation varied with the medium used. The highest frequency ($1.6\times10-5$ per recipient) was obtained on ISP medium 2 containing 10mM MgCl2. Southern blot and phenotypic analyses of exconjugants revealed that S. lavendulae FRI-5 contains a unique C31 attB site, and that integration of heterologous DNA into the attB site did not interfere with morphological differentiation or IM-2-dependent signal transduction, including the production of a blue pigment. This system will now enable detailed genetic analysis of the regulation of antibiotic production in S. lavendulae FRI-5.

• Preventive Nutrition and Food Science
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• 제5권4호
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• pp.200-204
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• 2000

Protein conjugation of curdlan belonging to $\beta$-1, 3-glucan was carried out to improve it surface functionalities. The glucan was mixed with phosvitin, {TEX}$$\alpha$_{s}${/TEX}-casein, lysozyme or ovalbumin, respectively. The mixture was freeze-dried, and he resulting powder was incubated at 6$0^{\circ}C$ and 79% relative humidity for 12 days in order to generate a controlled Maillard reaction between curdlan and proteins. conjugation with unfolding proteins, i.e., phosvitin and {TEX}$$\alpha$_{s}${/TEX}-casein, drastically increased the solubility of the glucan, whereas lysozyme and ovalbmin did not. The solubility in water of curdlan was 3.44% for the phosvitin conjugate and 1.09% for the {TEX}$$\alpha$_{s}${/TEX}-casein conjugate. SDS-slab polyacrylamide gel electrophoresis showed that curdlan was solubilized due to covalent binding with phosvitin. Emulsifying properties of curdlan were substantially improved by the conjugation with phosvitin and {TEX}$$\alpha$_{s}${/TEX}-casein. Emulsion stability of the curdlan-phosvitin conjugate was about 2.9 times greater than that of the curdlan-phosvitin mixture.

• 대한방사성의약품학회지
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• 제7권2호
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• pp.85-91
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• 2021

Selective amino acid conjugation of bulky antibodies is a valuable asset for real-time diagnosis and therapy. However, selective conjugation incorporating a chelate-bearing radioactive atom into an antibody without affecting its immunoreactivity is a challenging task. A bifunctional chelator (BFC), a selective amino acid-targeting probe, and a linker have been developed to overcome this problem. Here, we report the synthesis of a novel propylene cross-bridged chelator (PCB)-1,8-N,N'-bis-(carboxymethyl)-1,4,8,11-tetraazacyclotetradecane (TE2A)-luminol BFC via a click reaction and radiolabel it with a ⁶⁴Cu ion for tyrosine-selective conjugation of trastuzumab. In the initial optimization study, we tried different oxidative addition conditions such as electro-oxidation, hemin, horseradish peroxidase, iodogen tube, chloramine-T, and iodo beads. In this study, up to 82% of ⁶⁴Cu-PCB-TE2A-luminol was conjugated with the antibody in an iodo bead-catalyzed oxidative addition reaction with an isolated yield of 24.4%.

• Journal of information and communication convergence engineering
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• 제5권2호
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• pp.121-125
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• 2007

In this paper, a planar active retrodirective four-element array with subharmonic phase conjugation mixers based on anti-parallel diode pairs (APDPs) is designed, and its application in the auto-tracking duplex communication link is presented. As compared to previous phase conjugation mixers using twice RF frequency for LO frequency, the proposed conjugation mixers need only half RF frequency so that it can be easily applied for millimeter-wave applications. The proposed architecture, which conventionally performs the function of the transmission of an incident signal back in the direction of its source, is modified in order to include a receive function. Experimental verification of these architectures is performed at 1GHz and the results from the prototypes are compared with a theoretical model.

• Journal of information and communication convergence engineering
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• 제14권2호
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• pp.71-77
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• 2016

The combination of dispersion management (DM) and midway optical phase conjugation (OPC) is one of the promising techniques for compensating for optical signal distortion due to group velocity dispersion and nonlinear fiber effects. However, in this combination technique, midway OPC restricts the flexible optical link configuration. Therefore, the possibility of implementing the flexible optical link configuration with non-midway OPC applied to complete inline DM links is investigated in this study. It is confirmed that although the compensation using non-midway OPC for the distorted WDM channels is less effective than that using midway OPC, when non-midway OPC is placed at positions closer to the transmitters, the deployment of precompensation (i.e., the sequence of DCF + SMF)-OPC-postcompensation (i.e., the sequence of SMF + DCF) is more advantageous for the compensation. On the other hand, inverse deployment with respect to OPC (i.e., postcompensation-OPC-precompensation) is more advantageous when non-midway OPC is placed at positions closer to the receivers.

• 대한미생물학회지
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• 제22권1호
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• pp.95-99
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• 1987

When tetracycline resistancy were cured by ethidium bromide treatment, some of the cured strains lost the tetracycline resistance plasmid while other strains kept the plasmids. Both strains of lost and remained plasmids were digested with restriction endonuclease Hind III and these cleaved plasmids were compared with that of parent strains, two plasmid remained strains showed same cleavage patterns between parent and cured strains, however, one plasmid lost strain showed dissimilarity with parent strain, but in the other one strain, among 4 plasmid lost colonies, 2 showed same but other 2 showed different patterns compared to parent strain. Tetracycline was transfered by conjugation in on set(Staphylococcus aureus donor versus Staphylococcus epidermidis, recipient) with relative high frequency but the other 2 sets showed a low degree of frequency and the other 2 sets exhibited no transfer.

• Bulletin of the Korean Chemical Society
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• 제23권9호
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• pp.1253-1309
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• 2002

1,3,5-Tricyano-2,4,6-tris[2-(thiophen-2-yl)vinyl]benzene derivatives have been synthesized as a new type of octupolar nonlinear optical molecules and their linear and nonlinear optical properties were determined. The λmax values increa sed with the conjugation length and as the conjugation bridge was changed from phenyl to thienyl group. For phenyl and thiophene derivatives, the b value increased with conjugation length. In contrast, the $\beta$ values of the thiophene derivatives were much smaller than the corresponding phenyl derivatives.

• The Journal of the Acoustical Society of Korea
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• 제24권2E호
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• pp.61-66
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• 2005

Experimental work in underwater acoustic communications using passive phase conjugation has shown that the demodulation error depends on the relative drift rate between the source and receiver [Rouseff et al., IEEE J. Oceanic Eng. 26, 821-831 (2001)]. The observed effect involves the mismatch between the initial impulse response and the subsequent response after the source or receiver has changed locations. In the present work, the effect of drifting source is analyzed by numerical simulations and compared to the experimental results. The communications bit error rate is qualified as a function of drift rate, drifting direction, and source-receiver range.