• 한국자원식물학회지
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• 제29권2호
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• pp.189-203
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• 2016

본 연구는 진강산의 관속식물상을 밝히고 주요 식물을 조사하였다. 2014년 3월부터 11월까지 총 11회에 걸쳐 현지조사를 실시한 결과 관속식물은 114과 336속 495종 7아종 53변종 4품종 1교잡종으로 총 560분류군이 확인되었다. 식물다양성이 높은 순서는 화본과(11.0%), 국화과(10.8%), 사초과(8.8%), 장미과(4.6%), 꿀풀과(4.3%)이었다. 한반도 고유종은 서울제비꽃, 키버들, 백운산원추리, 늦둥굴레 4분류군이 확인되었다. IUCN 평가기준에 따른 적색목록식물은 4분류군으로 준위협종(NT) 에 큰제비고깔, 미평가종(NE)에 산들깨, 대구사초, 늦둥굴레가 조사되었다. 식물구계학적 특정식물은 IV등급 2분류군, III등급 3분류군, II등급 8분류군, I등급 15분류군으로 총 28분류군이 발견되었다. 귀화식물은 44분류군으로 귀화율 7.9%, 도시화지수 13.7%로 나타났다.

• Journal of Microbiology and Biotechnology
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• 제18권3호
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• pp.449-456
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• 2008

Phenotypic screening for bile salt hydrolase (BSH) activity was performed on Lactobacillus acidophilus PF01 isolated from piglet feces. A gene encoding BSH was identified and cloned from the genomic library of L. acidophilus PF01. The bsh gene and surrounding regions were characterized by nucleotide sequence analysis and were found to contain a single open reading frame (ORF) of 951 nucleotides encoding a 316 amino acid protein. The potential bsh promoter region was located upstream of the start codon. The protein deduced from the complete ORF had high similarity with other BSHs, and four amino acid motifs located around the active site, FGRNXD, AGLNF, VLTNXP, and GXGXGXXGXPGD, were highly conserved. The bsh gene was cloned into the pET21b expression vector and expressed in Escherichia coli BLR(DE3) by induction with 0.1mM of isopropylthiogalactopyranoside. The BSH enzyme was purified with apparent homogeneity using a $Ni^{2+}$-NTA agarose column and characterized. The overexpressed recombinant BSH enzyme of L. acidophilus PF01 exhibited hydrolase activity against tauroconjugated bile salts, but not glycoconjugated bile salts. It showed the highest activity against taurocholic acid. The maximum BSH activity occurred at approximately $40^{\circ}C$. The enzyme maintained approximately 70% of its maximum activity even at $60^{\circ}C$, whereas its activity rapidly decreased at below $37^{\circ}C$. The optimum pH was 6, and BSH activity was rapidly inactivated below pH 5 and above pH 7.

• 식물병연구
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• 제18권3호
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• pp.231-235
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• 2012

본 연구는 citrus에 심각한 피해를 초래하는 바이러스인 ICRSV가 국내로 유입되는 것을 차단하여 그로 인한 피해를 방지하기 위해 이를 진단하는 시스템을 구축하고자 하였다. ICRSV가 감염된 시료를 구할 수 없어 외피단백질 유전자를 E. coli의 codon usage를 고려하여 optimization한 뒤 E. coli에서 수용성 단백질로 과발현된 재조합 ICRSV 외피단백질을 정제하였다. 정제한 재조합 단백질을 이용해 제작한 복클론 항체는 $1{\times}10^{-4}$으로 희석하였을 때 western blot과 ELISA를 통해서 각각 10 ng, 5 ng의 재조합 ICRSV 외피단백질을 검출할 수 있었다. 이로써 제작된 항체를 이용하여 소량의 바이러스 입자만으로도 ICRSV를 검출할 수 있을 것이다.

• Bulletin of the Korean Chemical Society
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• 제32권9호
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• pp.3223-3228
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• 2011

To quantify the presence of mercuric ions in aqueous solution, double-stranded DNA (dsDNA) of poly(dT) was employed using a light switch compound, $Ru(phen)_2(dppz)^{2+}$ (1) which is reported to intercalate into dsDNA of a right-handed B-form. Addition of mercuric ions induced the dehybridization of poly(dT)${\cdot}$poly(dA) duplexes to form a hairpin structure of poly(dT) at room temperature and the metal-to-ligand charge transfer emission derived from the intercalation of 1 was reduced due to the dehybridization of dsDNA. As the concentration of $Hg^{2+}$ was increased, the emission of 1 progressively decreased. This label-free emission method had a detection limit of 0.2 nM. Other metal ions, such as $K^+$, $Ag^+$, $Ca^{2+}$, $Mg^{2+}$, $Zn^{2+}$, $Mn^{2+}$, $Co^{2+}$, $Ni^{2+}$, $Cu^{2+}$, $Cd^{2+}$, $Cr^{3+}$, $Fe^{3+}$, had no significant effect on reducing emission. This emission method can differentiate matched and mismatched poly(dT) sequences based on the emission intensity of dsDNA.

• Journal of Periodontal and Implant Science
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• 제37권sup2호
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• pp.339-351
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• 2007

Cytolethal distending toxin(CDT)은 세포 주기 중 G2에서 M 기로의 전환을 막아 세포의 증식을 억제할 수 있는 세균 단백 독소의 일종이다. 구강 미생물 중 유일하게 Actinobacillus actinomycetemcomitans (A. actinomycetemcomitans)만이 이 CDT를 생성 할 수 있는 것으로 알려져 있다. A. actinomycetemcomitans는 localized aggressive periodontitis (LAP)의 원인균으로 여겨지며 비 운동성의 그람 음성 구간균이고 $37^{\circ}C$, 5% $CO_2$ 하에 성장이 왕성하다. A. actinomycetemcomitans의 CDT는 3개의 인접한 유전자인 cdtA, cdtB, cdtC에 의해 형성 되며 각각의 유전자에 대한 단백질의 기능은 아직 완전히 밝혀지지 않았다. 현재까지 연구에 의하면 cdtA는 CDT의 세포부착과 관련이 있는 것으로 여겨지며 이 유전자의 기능 이상 시 CDT의 독성 효과가 현저히 감소한다고 알려져 있다. 따라서 본 연구는 A. actinomycetemcomitans의 cdtA 유전자를 클로닝, 단백질 발현하여 향후 치주질환의 발병 과정에서 CdtA의 역할을 규명하고 질환의 예방 및 치료법에 도움을 주고자 하였다. A. actinomycetemcomitans Y4균주를 cdtA 유전자 클로닝을 위해 사용하였다. A. actinomycetemcomitans의 genomic DNA는 genomic DNA 추출 kit를 사용하여 분리하고 cdtA에 특이적인 primer를 이용하여 PCR을 통해 cdtA 유전자를 증폭하였다. 증폭된 cdtA 유전자를 T-vector에 클로닝 하였으며, 클로닝 된 cdtA 유전자는 단백질 발현을 위해 pRSET Avector에 서브클로닝 한 후 발현 균주인 BL21(DE3)를 이용하여 발현시켰다. 발현 후 Ni-NTA AP conjugate를 이용한 Western blot을 통해 pRSET-CDTA를 확인하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
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• pp.290-293
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• 2003

Ohmic contact characteristics of Al ion implanted n-type SiC wafer were investigated. Al ions implanted with high dose to obtain the final concentration of $5{\times}10^{19}/cm^3$, then annealed at high temperature. Firstly, B ion ion implanted p-well region were formed which is needed for fabrication of SiC devices such as DIMOSFET and un diode. Secondly, Al implanted high dose region for ohmic contact were formed. After ion implantation, the samples were annealed at high temperature up to $1600^{\circ}C\;and\;1700^{\circ}C$ for 30 min in order to activate the implanted ions electrically. Both the inear TLM and circular TLM method were used for characterization. Ni/Ti metal layer was used for contact metal which is widely used in fabrication of ohmic contacts for n-type SiC. The metal layer was deposited by using RF sputtering and rapid thermal annealed at $950^{\circ}C$ for 90sec. Good ohmic contact characteristics could be obtained regardless of measuring methods. The measured specific contact resistivity for the samples annealed at $1600^{\circ}C\;and\;1700^{\circ}C$ were $1.8{\times}10^{-3}{\Omega}cm^2$, $5.6{\times}10^{-5}{\Omega}cm^2$, respectively. Using the same metal and same process of the ohmic contacts in n-type SiC, it is found possible to make a good ohmic contacts to p-type SiC. It is very helpful for fabricating a integrated SiC devices. In addition, we obtained that the ratio of the electrically activated ions to the implanted Al ions were 10% and 60% for the samples annealed at $1600^{\circ}C\;and\;1700^{\circ}C$, respectively.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.341-341
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• 2012

Recently, oxide semi-conductor materials have been investigated as promising candidates replacing a-Si:H and poly-Si semiconductor because they have some advantages of a room-temperature process, low-cost, high performance and various applications in flexible and transparent electronics. Particularly, amorphous indium-gallium-zinc-oxide (a-IGZO) is an interesting semiconductor material for use in flexible thin film transistor (TFT) fabrication due to the high carrier mobility and low deposition temperatures. In this work, we demonstrated improvement of flexibility in IGZO TFTs, which were fabricated on polyimide (PI) substrate. At first, a thin poly-4vinyl phenol (PVP) layer was spin coated on PI substrate for making a smooth surface up to 0.3 nm, which was required to form high quality active layer. Then, Ni gate electrode of 100 nm was deposited on the bare PVP layer by e-beam evaporator using a shadow mask. The PVP and $Al_2O_3$ layers with different thicknesses were used for organic/inorganic multi gate dielectric, which were formed by spin coater and atomic layer deposition (ALD), respectively, at $200^{\circ}C$. 70 nm IGZO semiconductor layer and 70 nm Al source/drain electrodes were respectively deposited by RF magnetron sputter and thermal evaporator using shadow masks. Then, IGZO layer was annealed on a hotplate at $200^{\circ}C$ for 1 hour. Standard electrical characteristics of transistors were measured by a semiconductor parameter analyzer at room temperature in the dark and performance of devices then was also evaluated under static and dynamic mechanical deformation. The IGZO TFTs incorporating hybrid gate dielectrics showed a high flexibility compared to the device with single structural gate dielectrics. The effects of mechanical deformation on the TFT characteristics will be discussed in detail.

• 수산해양교육연구
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• 제24권6호
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• pp.833-844
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• 2012

This study was conducted to obtain basic data which can be applied to process of canned boiled Kwamaegi. Commercial Kwamaegi was cut into $2{\times}3$ cm lengths, filled 90 g into can (301-3) and added with 60 g water and then precooked for 10 min. at $100^{\circ}C$. And water layer was drained. The precooked Kwamaegi was packed into the can, and added with 60 g of mixed salt solution, which is mixed with salt 0.5% and bamboo salt 0.7%. The cans were seamed using a vacuum seamer, and then sterilized for various Fo values (Fo 8~12 min.) in a steam system retort at $121^{\circ}C$. pH, VBN, amino-N, total amino acid, free amino acid, color value (L, a, b), texture profile, TBA value, mineral, sensory evaluation and viable bacterial count of the canned boiled Kwamaegi produced with various sterilization condition(Fo 8~12 min.) were measured. There was no remarkable difference between sterilization conditions and sensual characteristics. The results showed that the product sterilized at Fo 8 min. was the most desirable because this condition is the most economical and tasty.

• 한국환경생태학회지
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• 제29권2호
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• pp.105-131
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• 2015

This study was carried out to investigate the flora of Gyodongdo island (Ganghwa-gun). The vascular plants from 11 field surveys were revealed to belong to a total of 629 taxa; 118 families, 364 genera, 561 species, 5 subspecies, 53 varieties, 7 forms and 3 hybrids. 184 taxa were the first records from this region. The plants in Gyodongdo island are composed of the deciduous broad-leaved and conifer-mixed forests which are the common ones in the middle part of the Korean Peninsula. Five taxa of Korean endemic plants such as Clematis brachyura Maxim., Viola seoulensis Nakai, Populus ${\times}$ tomentiglandulosa T. B. Lee, Forsythia koreana (Rehder) Nakai and Hemerocallis hakuunensis Nakai were collected. Endangered wild plants designated by the law called 'Protection Law for Endangered wild fauna and flora' were one taxon. The red list plants according to IUCN valuation basis were examined for 13 taxa; endangered (EN) species of Prunus yedoensis Matsum., Vulnerable (VU) species of both Utricularia pilosa (Makino) Makino and Iris ruthenica var. nana Maxim., Near Threatened (NT) species of Senecio argunensis Turcz., Least Concern (LC) species of Platycladus orientalis (L.) Franco, Potentilla discolor Bunge, Limnophila sessiliflora (Vahl) Blume, Acorus calamus L., Phacelurus latifolius (Steud.) Ohwi, Pseudoraphis ukishiba Ohwi, Belamcanda chinensis (L.) DC., and Not Evaluate (NE) species of both Astragalus sikokianus Nakai and Potamogeton oxyphyllus Miq. The floristic regional indicator plants found in this area were a total of 47 taxa comprising three taxa of grade V, four taxa of grade IV, nine taxa of grade III, 10 taxa of grade II, and 21 taxa of grade I. The naturalized plants were identified as 62 taxa and the percentage of naturalized index (NI) was 9.9 % and the percentage of urbanization index (UI) was 19.3 %, respectively. Furthermore, hemicryptophytes (28 %), therophytes (26 %), hydrophytes (13 %) and geophyte (12 %) showed high proportional ratio in life form spectrum.

• Nuclear Engineering and Technology
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• 제50권3호
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• pp.470-477
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• 2018

With a highly functional methyl vinyl silicone rubber (VMQ) matrix and filler materials of $B_4C$, PbO, and benzophenone (BP) and through powder surface modification, silicone rubber mixing, and vulcanized molding, a flexible radiation shielding and resistant composite was prepared in the study. The dispersion property of the powder in the matrix filler was improved by powder surface modification. BP was added into the matrix to enhance the radiation resistance performance of the composites. After irradiation, the tensile strength, elongation, and tear strength of the composites decreased, while the Shore hardness of the composites and the crosslinking density of the VMQ matrix increased. Moreover, the composites with BP showed better mechanical properties and smaller crosslinking density than those without BP after irradiation. The initial degradation temperatures of the composites containing BP before and after irradiation were $323.6^{\circ}C$ and $335.3^{\circ}C$, respectively. The transmission of neutrons for a 2-mm thick sample was only 0.12 for an Am-Be neutron source. The transmission of ${\gamma}$-rays with energies of 0.662, 1.173, and 1.332 MeV for 2-cm thick samples were 0.7, 0.782, and 0.795, respectively.