• Korean Journal of Plant Taxonomy
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• v.43 no.4
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• pp.252-262
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• 2013

During the floristic survey on Phnom Bokor National Park, Kampot, Cambodia, we encountered Balanophora fungosa var. indica, which is a tropical holoparasitic plant. To identify its host species, we collected host roots and trees nearby and tried to identify them using DNA barcoding approach. We applied plastid rbcL and matK gene regions as DNA barcode markers, and successfully amplified and sequenced the markers from 15 host roots and seven tree samples. Obtained host root sequences were identified as Primulaceae, Celastraceae, Myrtaceae, and Oleaceae, while trees nearby are Oleaceae, Myrtaceae, Sapindaceae, Rosaceae, Clusiaceae, Ericaceae, and Lauraceae. At genus level, host species are identified as Myrsine, Euonymus, Syzygium, and Olea, but failed in species discrimination. Myrsine (Primulaceae) and Olea (Oleaceae) are reported here as host species of B. fungosa var. indica for the first time. Further sampling and comparative work, and DNA barcoding will help recognize the biodiversity of the area and host species of Balanophora, together with their evolution.

• Polymer(Korea)
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• v.33 no.3
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• pp.213-218
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• 2009

A cationic lipid emulsion containing 1,2-dioleoyl-3-trimethylammonium-propane(DOTAP), Tween80, squalene has been prepared as a gene delivery system. In order to increase the transfection efficiency of gene carrier, folate was used as the tumor-targeting ligand that was attached on PEG-DPPE. HeLa and 293 cells were used for the in vitro transfection experiment. HeLa cell is a folate-positive cell line. The mean particle sizes of polymeric lipid system and DNA/lipid complex system were 206.6 nm and 150.5 nm, respectively. The transfection efficiencies of our carriers(4:l(w:w) complex ratio)were 100 times higher than that of DOTAP only emulsion due to the targeting effect of folate.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04a
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• pp.955-957
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• 2004

DNA 마이크로어레이(microarray)란 새로운 개념의 기술이 도입되면서, 이를 이용하여 유전체(genome)를 탐색하거나, 동시에 수천 개의 유전자간의 상호작용을 관찰 할 수 있게 되었다. 이러한 이점으로 인하여, 많은 DNA 마이크로어레이 실험이 시행되고 있다. DNA 마이크로어레이 실험으로 생성되는 이미지 데이터는 그 양이 방대하고, 분석하는 연구자에 따라 판정이 달라질 수 있으므로, 이를 효율적으로 분석할 수 있는 방법들이 필요하게 되었다. 하지만, 마이크로어레이 이미지 데이터는 반점(Spot) 위치의 변동이나 반점의 모양, 크기가 고르지 않는 것과 칼은 다양한 문제로 인하여 자동적으로 분석하기는 어렵다. 본 논문에서는 마이크로어레이의 균일 격자(regular grid) 구조 탐색을 이용하여 새로운 주소 결정 알고리즘을 소개한다.

• Proceedings of the Korean Society for Cognitive Science Conference
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• 2005.05a
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• pp.177-181
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• 2005

기계학습에서 커널을 이용한 방법은 그 응용범위가 기계학습의 전반에 걸쳐 다양하게 이용되고 있으며, 그 성능 또한 기존의 방법들을 앞지르고 있다. 이는 기존의 비선형적 접근을 커널을 이용한 고차원 공간에서의 선형적 접근법으로 바꿈으로써 가능하게 되는 것이다. 다양한 분야에 적용되는 많은 커널들이 존재하며 각 커널들은 특별한 분야에 적용되기 쉽도록 다른 형태를 띠고 있기도 하지만, 커널로서 작용하기 위해 양한정 조건(positive definiteness)을 만족해야 한다. 본 연구에서는 DNA 문제에 직접 적용시킬 수 있는 방법으로서의 새로운 커널을 제시한다. 또한 매트로폴리스(Metropolis) 알고리즘을 이용하여 DNA의 hybridization과정을 모사함으로써 새로운 종류의 커널이 양한정(positive definite) 조건을 만족시킬 수 있는 방법을 제시한다. 새로 만들어진 커널이 행렬값을 형성해 나가는 과정을 살펴보면 인간이 예(instance)로부터 개념을 형성해 나가는 과정과 흡사한 양상을 보이는 것을 알 수 있다. 개념을 나타내는 좋은 예로서의 표본(prototype)으로부터 개념이 형성되어 가는 과정은 표본(prototype)이 아닌 예로부터 개념이 형성되는 과정과 다른 양상을 띠는 것과 같은 모양을 보인다.

• The Korean Journal of Food And Nutrition
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• v.10 no.2
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• pp.268-271
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• 1997

Human mitochondrial aldehyde dehydrogenase(ALDH2) is mainly responsible for the oxidation of acetaldehyde generated during alcohol oxidation in vivo. To investigate the role of ALDH2 in alcohol metabolism, it was needed to get solubilized enzyme. The cDNA of ALDH2 is isolated from cDNA library and ligated to several expression vectors for E. coli. At almost expression system to be constructed, the broad expression band of ALDH2 was detected. But, the large part of the expressed protein consisted as inclusion body, the yield of solubilized enzyme was not more tan 5% of the total expressed amount. Recombinant ALDH2 was verified from the several expression systems.

• Korean Journal of Animal Reproduction
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• v.24 no.3
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• pp.299-309
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• 2000

This study was performed 1) to establish the optimal PCR condition of sex determination in Hanwoo IVM/IVF embryos, 2) to examine the sex determination and sex ratio to the developmental stages of Hanwoo IVM/IVF embryos by two-step PCR method. The sexing of bovine IVF embryos were accurately determined by PCR methods using Y chromosome specific DNA primer(BOV 97M, 141bp) and bovine specific DNA primer(216bp). The fregment size were shown at 141 and 216 base pairs(bp) in male, and 216 bp in female. Two-steps PCR method in which the samples were amplified by 15 cycles with Y chromosome specific DNA primer and then amplified by additional 30 cycles with bovine specific DNA primer was effective in the sexing of bovine IVF embryos. The zona-free embryos were more effective than zona-intact embryos in bovine IVF embryo sexing. The appearance of Y chromosome specific band was 45.2% in embryos treated with protease K and 53.3% in embryos treated with freezing and thawing repeatedly. The optimun volume of DNA for sexing of Hanwoo IVF embryos were 2 to 10 $\mu$1 in Zona-free embryos and 12 to 13 $\mu$1 in zona-intact embryos. The sexing rate of bovine IVF embryos by PCR was 96.0% and questionable rate not identified sex was 4.0%, respectively. Among the sexed embryos, the percentage of male and female was 49.7% and 46.3%, respectively, the sex ratio was 1: 1.1. The successful rate of embryo sexing was increased to the developmental stages.

• Korean journal of applied entomology
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• v.34 no.2
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• pp.100-105
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• 1995

A whole body extract (WBE), a crude nuclear fraction, of aphids was prepared and used to identify the proteins which bound specifically to 5'-upstream regions of the transcription initiation site of the aphid ribosomal RNA gene (rDNA). While DNA fragment (-263/-195) was bound by only one specific 53 kDa protein, two DNA fragments, A(-194/23) and B(-393/-264), were commonly bound by three proteins (52 kDa, 50 kDa and 40 kDa). It was also revealed that the formation of he DNA-protein complex requires a cation.

• Journal of Life Science
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• v.7 no.3
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• pp.167-171
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• 1997

As an initial effort to elucidate RNA: protein binding in a way to regulate translation initiation and phosphorylation, a cDNA encoding a double-stranded RNA binding factor (RBFII)was isolated from Hela ZAPII cDNA library by affinity screening using [$\alpha$$^{-32}$P] UMP-labeled HIV Rev-responsive element(RRE) RNA. The nucleotide sequence of RBF (or TRBP) cDNA except the 5’end. At the 5’end, This common ORF was fused in-frame to N-terminal residues of Lac-Z through a unique 138 nt sequence encoding 46residues in the case of RBFII and a 63 nt sequence encoding 21 residuces in the case of RBFI. The context of ATG appearing first in the sequences suggests that both these cDNA inserts are incomplete at the 5’end.

• Journal of the Korean Chemical Society
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• v.44 no.1
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• pp.4-9
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• 2000

We investigated the self-association and protonation state of norfloxacin, a member of quinokme antibiotics, using electric absorption and potentiom,etric titration. Both nitrogen at the piperazine ring and carboxylic acid were protonated at a low pH (cationic norfloxacin), and deprotonated at a high pH (anionic norfloxacin). In the intermediate pH range, a neutral species was dominant with the possibility of forming a zwitter ion. We also observed that nortloxacin molecules can be sracked to form a dimer at an intermediate pH, The equilibrium constant of the norfloxacin-DNA complex formation, which was measured by Stem-Volmermethod, increases as the pH of the system is lowered. This observation indicates that it is the cationic nortloxacin that forms a complex with DNA among various norfloxacin species in aqueous solution.

• Journal of Yeungnam Medical Science
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• v.15 no.2
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• pp.237-245
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• 1998

만성 B형 간염 환자에서 Interferon (IFN) 치료 후 혈청 HBeAg 소실 및 anti-HBe의 양전율을 높이고 효율적인 치료의 근거를 알기 위하여 치료 전 간기능검사상 갑자기 상승한 혈청 ALT치를 나타낸 환자군과 그렇지 않은 대조군을 대상으로 하여 IFN을 투여한 군과 IFN 치료없이 정상 HBeAg의 자연 소실을 보인 환자군을 임상적으로 장기간 관찰하고 조사하였다. ALT치가 정상 상한치의 4배 이상 높이 증가되어 3개월 이상 왕복을 보인 40명의 환자(A군)와 ALT치가 정상 상한치의 3배 이하로 증가된 10명(B군)에게 ${\alpha}$-IFN 2b를 매일 300만 단위 피하주사로 3~12개월 주사하였다. 대조군으로는 ALT치가 A군처럼 장승한 45명 (C군)이었으며, IFN 치료없이 평균 2.9년을 관찰하였다. HBeAg/anti-HBe 혈청 양전율은 A군 68%, B군 20%, C군 13%이었으며 IFN 치료 중단 후 1년까지의 HBeAg 재양성율은 A군에서 29%였고 HBeAg이 소실된 A와 B군의 38명중에서 6명에서 HBV DNA가 양성이었다. 6명중 4명은 HBeAg/anti-HBe 양전을 보였으나 HBV DNA 양성이었고 나머지 2명은 HBeAg, anti-HBe 및 HBV DNA (hybridization) 모두 음성이었으나 중합효소연쇄반응검사상 HBV DNA 양성이었다. 이상의 결과를 보면 비록 IFN 치료 후에 HBeAg이 소실되었다가 다시 양성화되더라도 IFN은 단기간내에 혈중 HBeAg이나 DNA가 자연적으로 감소가 될 환자나 그렇지 않은 환자에게도 HBV의 비증식화를 유발하여 도움이 될 것으로 사료된다. 그러나 IFN 투여 후에도 혈중 HBeAg과 DNA 소실에 전혀 도움이 되지 않을 환자 및 HBV 증식 억제효과가 기대되는 HBV 간질환 환자의 조건, IFN 투여량, 기간 등에 대한 계획적이고 체계적인 연구로 더 나은 치료효과를 기대할 수 있으리라 생각된다.