• Journal of Life Science
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• v.13 no.6
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• pp.799-804
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• 2003

In order to verify the occurrence of an estrogenic compound in natural products, the estrogenic activity was measured using an in vitro detection system. For this system, human breast cancer cell line MCF7 was transfected using an estrogen responsive CAT reporter plasmid. Estrogenic activities of photosynthetic algae spirulina and sea lettuce were evaluated using this system. Estrogenic activities of a $500\mug/ml\; and\; 50 \mug/ml$ ethanol extracts of spirulina were as much as that of $10^{-8}$M standard solution (17$\beta$-estradiol) and activity of $5\mug/ml$ ethanol extract of spirulina was as much as that of $10^{-10}$ M standard solution. However, no significant estrogenic activity was observed using sea lettuce extract. Estrogenic activities of marine animals, such as star fish and shrimp, were also evaluated using this system, however, no significant estrogenic activity was observed in these extracts. In this result, it is confirmed that spirulina extract possesses estrogenic compound.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.269-269
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• 2016

최근, 플렉서블 광전자소자 제작 기술의 눈부신 발전으로, 기존의 평면형 이미지 센서가 가지고 있는 여러가지 한계를 극복하기 위해 곡면형 이미지 센서 제작에 대한 다양한 연구가 진행되고 있다. 리소그래피, 물질 성장, 도포, 에칭 등의 대부분의 반도체 공정은 평면 기판에 기반한 공정 방법으로 곡면 구조의 이미지 센서를 제작하기에는 많은 어려움이 있다. 본 연구에서는 곡면형 이미지 센서의 제작을 위해 곡면 구조 위에서의 직접적인 공정 대신 평면 기판에서 단결정 실리콘을 이용해 전사 인쇄가 가능하고 수축이 가능한 초박막 구조의 이미지 센서를 제작한 후 이를 떼어내는 방식을 이용하였다. 이온 주입 및 건식 식각 공정을 통해 평면 SOI (Silicon on Insulator) 기판 위에 단일 광다이오드 배열 형태의 소자를 제작한 후 수 차례의 폴리이미드 층 도포 및 스퍼터링을 통한 금속 배선 공정을 통해 초박막 형태의 광 검출기를 완성한다. 이후 습식 식각 및 폴리디메틸실록산(PDMS) 스탬프를 이용한 전사 인쇄 공정을 통해 기판으로부터 디바이스를 분리하여 변형 가능한 형태의 이미지 센서를 얻을 수 있다. 이러한 박막형 이미지 센서는 유연한 재질로 인해 수축 및 팽창, 구부림과 같은 구조적 변형이 가능하게 되어 겹눈 구조 카메라, 튜너블 카메라 등과 같이 기존 방식의 반도체 공정으로는 구현할 수 없었던 다양한 이미징 시스템 개발에 적용될 수 있을 것으로 기대된다.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.395-399
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• 2007

Renewable energy sources such as wind energy is copiously available without any limitation. Wind turbines are used to tap the potential of wind energy which is available in millions of megawatt. Reliability of wind turbine is critical to extract this maximum amount of energy from the wind. We reviewed different techniques, methodologies, and algorithms developed to monitor the performance of wind turbine as well as for an early fault detection to keep away the wind turbines from catastrophic conditions due to sudden breakdowns. To keep the wind turbine in operation, implementation of Condition Monitoring System (CMS) is paramount, and for this purpose ample knowledge of these types of system is mandatory. So, an attempt has been made in this direction to review maximum approaches related to CMS in this piece of writing.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.10
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• pp.112-118
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• 2021

In this study, an inspection method using a color image is proposed to conduct a real-time inspection of covalent organic framework (COF) films to detect defects, if any. The COF film consists of an upper pattern SR and a lower PI. The proposed system detects the defects of more than 20 ㎛ on the SR surface owing to the characteristics of the pattern, whereas on the PI surface, it detects defects of more than 4 ㎛ by utilizing a micro-optical system. In the existing system, it is difficult for the operator to conduct a full inspection through a high-performance microscope. The proposed inspection algorithm performs the inspection by separating each color component using the color contrast of the pattern on the SR side, and on the PI surface it inspects the bonding state of the mounted chip. As a result, it is possible to confirm the exact location of the defects through the SR and PI surface inspections in the implemented inspection.

• Microbiology and Biotechnology Letters
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• v.17 no.3
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• pp.263-268
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• 1989

To maximize the performance of recombinant cell fermentation process through optimizing environmental conditions, the production of invertase from recombinant Saccharomyces cerebisiae Containing SUC2 gene was studied as a model. The recombinant cells showed biphasic growth on glucose. Since the promoter of the SUC2 is regulated by the concentration of glucose in the medium, expression of invertase by recombinant yeast began when the glucose concentration decreased in a range of 0.25-0.4 g/L during the batch culture. Plasmid segregation occured frequently during glucose fermentation, and infrequently during ethanol oxidation. A rapid appearance of invertase activity with glucose was observed under nonaerated condition, and the maximum specific invertase activity was about 1.5 times as high as under aerobic condition, In fed batch culture, when n low level of glucose was continuously supplied to the tormentor after the time of glucose depletion during growth phase, specific and total invertase activity increased about 1.7 and 2.9 fold, respectively, in a batch culture.

• Korean Journal of Microbiology
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• v.52 no.1
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• pp.110-115
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• 2016

A small plasmid (pDK4) from the Antarctic marine organism Pseudoalteromonas sp. PAMC 21150, was purified, sequenced and analyzed. pDK4 was determined to be 3,480 bp in length with a G+C content of 41.64% and contains three open reading frames encoding a replication initiation protein (RepA), a conjugative mobilization protein (Mob) and a hypothetical protein. PCR-amplified pDK4 was cloned in high-copy pUC19 to yield the fusion vector pDOC153. The chloramphenicol resistance gene was inserted into pDOC153 to give an ampicillin and chloramphenicol-resistant, Pseudoalteromonas - Escherichia coli shuttle vector (7,216 bp; pDOC155). The TonB-dependent receptor (chi22718_IV ) and exochitinase (chi22718_III ) genes from Arctic marine P. issachenkonii PAMC 22718 were cloned into pDOC155 to produce pDOC158 and pDOC165, respectively. Both vector derivatives were transferred into plasmid-free Pseudoalteromonas sp. PAMC 22137 by the triparental mating method. PCR experiments showed that the genes were stably maintained both in Pseudoalteromonas sp. PAMC 22137 and E. coli $DH5{\alpha}$ cells, indicating the potential use of pDOC155 as a new gene transfer system into marine Pseudoalteromonas spp.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.29 no.2
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• pp.71-76
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• 2019

Recently, the demand of labels for product management is increasing, as the automation system becomes more common. the development of functional labels which can be used in various environments has been rapidly proceeded. In the case of a printed circuit board, barcode labels with thermal and chemical stability are generally used due to a high temperature process around $300^{\circ}C$ and chemical cleaning in the manufacturing process. However, the yellowing phenomenon of labels that can lower the resolution of printed barcode image still needs to be prevented. In this study, we prepared a composite coating layer using a silica inorganic binder and a titanium dioxide white pigment, and developed a functional labels with thermal and chemical stability. The silica inorganic binder prepared by sol-gel process was confirmed to show excellent adhesion and abrasion resistance with the polyimide film. The white coating layer could be formed on the polyimide film with mixing the silica inorganic binder and titanium dioxide white pigment. The prepared coating layer showed excellent whiteness and glossiness above $400^{\circ}C$. The excellent chemical stability of the coating layer was also confirmed by the chemical treatment with acidic (pH 1.6) and basic (pH 13.6) cleaners.

• Korean Journal of Microbiology
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• v.39 no.2
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• pp.118-122
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• 2003

To develop vector plasmid for the bacteriophage P2-P4 system which is a useful experimental tool for the study of viral capsid assembly, we constructed a new P4-derived vector plasmid starting from P4 ash8 sid71 With recombinant DNA technology, a portion of P4 genome was deleted and tetracyclin resistance gene (terR) was introduced into P4 genome to give P4 selectivity. Resulting P4 ash8(sid71) terR was 12.09 kb long and could be converted to a viable bacteriophage with P2 infection. The burst size of induced bacteriophage form of P4 ash8(sid71) terR was determined. The CsCl buoyant equilibrium density gradient experiment of new P4 derivative suggested the upper limit of packaging capacity in P2-size head.

• Microbiology and Biotechnology Letters
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• v.43 no.1
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• pp.79-83
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• 2015

The Cucurbitaceae are a plant family that consist of over a hundred genera, the most important of which are squash, pumpkin, zucchini, some gourds, cucumber and watermelon. These are among the top imported seeds in Korea. At the time of their import, the Squash mosaic virus (SqMV), the Cucumber green mottle mosaic virus (CGMMV) and the Kyuri green mottle mosaic virus (KGMMV) are designated as regulated viruses for quarantine in Korea. This study was conducted to develop specific primer sets for easy and rapid detection of SqMV, CGMMV and KGMMV. RT-PCR with the nested PCR primer sets and modified positive control plasmids were capable of highly sensitive detection and verification of such viruses. In addition, developed diagnostic PCR systems applied to quarantine sites detected 47 cases of SqMV, 67 cases of CGMMV and 17 cases of KGMMV between 2010 and the first half of 2014.

• Journal of Life Science
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• v.21 no.9
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• pp.1323-1328
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• 2011

We herein report the development of an agarose-gel-immobilized recombinant bacterial biosensor simple system for the field monitoring of phenolic compounds. Escherichia coli cells harboring the pLZCapR plasmid, which was previously designed to express the ${\beta}$-galactosidase reporter gene in the presence of phenolic compounds, were co-immobilized with a substrate [chlorophenol red ${\beta}$-galactopyranoside (CPRG) in agarose gel, and dispensed to the wells of a 96-well plate. Field samples were added to the wells and color development was monitored. In the presence of 5 ${\mu}M$ to 10 mM of phenol, the biosensor developed a red (representing hydrolysis of CPRG) color. Other phenolic compounds were also detected by this immobilized system, with the pattern resembling that previously reported for the corresponding non-immobilized biosensor. The immobilized cells showed optimum activity when the gel was simultaneously supplemented with 6% dimethyl formamide (DMF), 0.1% SDS and 10 mM $CaCl_2$. The immobilized biosensor described herein does not require the addition of a substrate or the use of unwieldy instruments or sample pretreatments that could complicate field studies.