• Journal of Microbiology and Biotechnology
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• v.7 no.5
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• pp.293-298
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• 1997

A 4.6-kb HindIII fragment encompassing the complete 140-kDa ${\alpha}$-amylase gene of Lactobacillus amylovorus B 4540 was cloned into pBR322 by the shot gun method. Southern blotting and restriction mapping for the insert were performed. The recombinant 9.0-kb plasmid, pFML1, conferred ${\alpha}$-amylase activity to E. coli and Lactococcus lactis hosts when introduced by electroporation. SDS-PAGE and zymography confirmed the production of 140-kDa ${\alpha}$-amylase and its proteolytic degradation products with enzyme activity in transformants. Total ${\alpha}$-amylase activity of E. coli $DH5{\alpha}$ cells harboring pFML1 was 1.8 units and most activity was detected from cell pellets. Total enzyme activity of L. lactis subsp. lactis MG1363 transformant was five to ten-fold lower than that of E. coli cell but more than half of the activity was detected in the culture supernatant.

• Journal of Haehwa Medicine
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• v.28 no.2
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• pp.1-11
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• 2019

Objective: The aim of this study is to analyze the previously published research articles related to puffer fish toxin focusing on tumor. Method: Literatures were searched in PubMed database, published since 2000, using the keyword; Puffer fish, Fugu and tetrodotoxin (TTX) with cancer or tumor. Research papers were classified by year, country, study model, used material, kind of tumor and study subject. Finally, a total of 41 studies were analyzed in this study. Results: From 2000 to 2018, the most abundant papers were published in 2009 (6 studies) and almost half of the papers were studied in United Kingdom (20 studies). The 39 studies used TTX purified from puffer fish while 2 studies used crude extract of skin and gonad of puffer fish. The most used target cell line was prostate cancer (15 studies), and the next was breast cancer (14 studies). The study methods were classified into 4 clinical studies, 2 animal studies and 35 cell-based studies. Conclusions: Our results show that the overview of cancer-related studies using puffer fish poison. This information would be helpful for the puffer fish-derived drug researches in the future.

• JSTS:Journal of Semiconductor Technology and Science
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• v.10 no.4
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• pp.316-324
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• 2010

In this paper, we design a 256 kbits EEPROM for a MCU (Microcontroller unit) with the wide voltage range of 1.8 V to 5.5 V. The memory space of the EEPROM is separated into a program and data region. An option memory region is added for storing user IDs, serial numbers and so forth. By making HPWs (High-voltage P-wells) of EEPROM cell arrays with the same bias voltages in accordance with the operation modes shared in a double word unit, we can reduce the HPW-to-HPW space by a half and hence the area of the EEPROM cell arrays by 9.1 percent. Also, we propose a page buffer circuit reducing a test time, and a write-verify-read mode securing a reliability of the EEPROM. Furthermore, we propose a DC-DC converter that can be applied to a MCU with the wide voltage range. Finally, we come up with a method of obtaining the oscillation period of a charge pump. The layout size of the designed 256 kbits EEPROM IP with MagnaChip's 0.18 ${\mu}m$ EEPROM process is $1581.55{\mu}m{\times}792.00{\mu}m$.

• The Journal of the Korean dental association
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• v.21 no.10 s.173
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• pp.805-812
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• 1983

For the assessment of peripheral blood leukocyte chemotaxis dysfunction in rapidly progressive periodontitis, peripheral blood leukocyte of 13 patients were isolated, and tested by the method of blind well chamber technique which was recently developed by Park. Data analysis was performed from the speed of cell migration from the bottom of filter paper to the top for 18 minutes at the condition of chemo-attractant(Zymosan-activated serum). Eight of the 13 patients (62%) exhibited statistically significant inhibition of leukocyte chemotaxis, 4 patients revealed normal function and the other one patients showed elevated leukocyte chemotaxis. Four of the 8 patients in chemotaxis dysfunction showed significant inhibition of random migration and chemotaxis dysfunction both. Two of these 4 patients exhibited random migration impairment, elevation of C.D.I. and chemotaxis dysfunction. The results indicated that the progression of rapidly progressive periodontitis was influenced by the leukocyte chemotaxis dysfunction, and half of these dysfunction was associated with cell-defect of leukocyte.

• International Journal of Industrial Entomology and Biomaterials
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• v.7 no.2
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• pp.197-201
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• 2003

The recombinant plasmids harboring a heterologous gene coding mouse endostatin were transfected and expressed stably in Trichoplusia ni Tn 5B1-4 cells and Bombyx mori BmN cells, respectively. Recombinant endostatin expressed in the stably transformed Tn 5B1-4 and BmN cells was secreted into the medium. BmN cells are relatively lower in maximum cell growth and recombinant endostatin production than Tn 5B 1-4 cells. Recombinant endostatin was also purified to homogeneity using a simple one-step ${Ni^2+}$ affinity fractionation method. Purified recombinant endostatin inhibited endothelial cell proliferation in a dose-dependent manner. The concentration at half-maximum inhibition $({ED_50})$ for recombinant endostatin was approximately 0.35 ${\mu}g$/ml.

• Journal of Ginseng Research
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• v.40 no.1
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• pp.62-67
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• 2016

Background: Ginseng, which is widely used in functional foods and as an herbal medicine, has been reported to reduce the proliferation of prostate cancer cells by mechanisms that are not yet fully understood. Methods: This study was designed to investigate the changes in ginsenoside content in ginseng after treatment with a microwave-irradiation thermal process and to verify the anticancer effects of the extracts. To confirm the anticancer effect of microwave-irradiated processed ginseng (MG), it was tested in three human prostate cancer cell lines (DU145, LNCaP, and PC-3 cells). Involvements of apoptosis and autophagy were assessed using Western blotting. Results: After microwave treatment, the content of ginsenosides Rg1, Re, Rb1, Rc, Rb2, and Rd in the extracts decreased, whereas the content of ginsenosides 20(S)-Rg3, 20(R)-Rg3, Rk1, and Rg5 increased. Antiproliferation results for the human cancer cell lines treated with ginseng extracts indicate that PC-3 cells treated with MG showed the highest activity with an half maximal inhibitory concentration of $48{\mu}g/mL$. We also showed that MG suppresses the growth of human prostate cancer cell xenografts in athymic nude mice as an in vivo model. This growth suppression by MG is associated with the inductions of cell death and autophagy. Conclusion: Therefore, heat processing by microwave irradiation is a useful method to enhance the anticancer effect of ginseng by increasing the content of ginsenosides Rg3, Rg5, and Rk1.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.1185-1192
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• 2001

This paper reviews available techniques for monitoring corrosion of steel in concrete. The need for early detection and diagnosis of corrosion related deterioration in reinforced structures is widely acknowledged. This is particularly important in reinforced concrete structures on account of the economic and social significance of the problem. The current generally used on-site procedure for corrosion monitoring of reinforced structures employs a method of half-cell surface potential measurements. While the technique has provided a useful means of delineating areas of high or low corrosion risk, there are difficulties in its use and interpretation when assessing rates of deterioration. Electrochemical techniques are by far the most suitable for corrosion monitoring purpose and meet most of the requirements. The aim of this paper is to describe the electric resistance sensor(ER sensor) and electrochemical techniques employed to monitor and estimate corrosion rates of reinforcement. Early detection and diagnosis of corrosion hazards allows preventive measures to be taken, hence the typically expensive repair of severely deteriorated structures can be avoided.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.04a
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• pp.269-272
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• 1997

The Lithium ion secondary battery has been developed for high energy density of portable electrical device and electronics. Among the many conductive polymer materials, the positive active film for Li polymer battery system was synthesized successfully from polyphenylene diamine(PPD) by chemical polymerization in our lab. And PPD-DMcT(2, 5-dimercapto-1, 3, 4-thi-adiazole) composite flim conductive material, at high temperature was also prerared with the addition of dimethylsulfoxide(DMSO). The surface morphology and thermal stability of prepared composite flim was carried out by using SEM and TGA, respectively. Electrochemical and electrical conductivity of composite flim were also discussed by cyclic voltammetry and four-probe method in dry box(<27pm). And the electrode reaction mechanism was detected and analyzed from the half cell unit battery system.

• Journal of Integrative Natural Science
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• v.2 no.1
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• pp.41-44
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• 2009

Photonic crystals containing multiple rugate structure are prepared by electrochemical etchings. Typically etched rugate PSi prepared in this study. Etching is carried out in a Teflon cell by using a two-electrode configuration with a Pt mesh counter electrode. They exhibit sharp photonic band gaps in the optical reflectivity spectrum. This reflectivity can be tuned to appear anywhere in the visible to near-infrared spectral range, depending on the programmed etch waveform. We study the method of full width half maxima and reflectivity index control by using amplitude.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.395-398
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• 2000

Recently, increasement of usage contents of sea sand in constructing concrete structures due to insufficiency of high quality river sand, led to many studies for steel corrosion and control methods on it in concrete. But, domestic studies for threshold chloride contents of steel corrosion are not so many as those of foreign states. In this study, the electrochemical test as half cell potential measurement and linear polarization method to estimate the corrosion of steel in contents mixed with several levels chloride contents was performed, thereby, pre-mixed chloride were compared with results measured quantitatively for steel corrosion. And, based on these data, a trial to determine threshold chloride contents of steel corrosion was made.