• 대한임상검사과학회지
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• 제50권2호
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• pp.197-204
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• 2018

다발성 골수종(MM)은 혈액 종양의 주요 사망 원인이다. 최근에 다발성 골수종 진단에 microRNA를 이용한 실험이 보고되고 있다. 이에 우리는 다발성 골수종 진단 마커로 miR-221을 이용 할 수 있는지 확인하고자 하였다. 본 연구는 다른 혈액학적 질환이 없는 다발성 골수종 환자 20명을 대상으로 하였다. MicroRNA 추출은 다발성 골수종 환자의 파라핀 포매 조직을 이용하였다. 우리는 다발성 골수종의 microRNA 표적 유전자로 miR-15a, miR-16, miR-21, miR-181a 그리고 miR-221을 선택하였다. 유의성 검정은 fold change 값을 기준으로 1.5이상 또는 -1.5 미만의 결과를 유의성이 있는 경우로 하였다. Fold change 값은 인간 유전자 SNORD43에 의해 표준화된 데이터를 기준으로 하였다. Fold change 값이 1.5 이상은 "overexpression", -1.5 미만의 값은 "underexpression"으로 정의되었다. miR-221의 65.0% (13/20)에서 "overexpression"으로 유의성이 있음을 확인하였고, 다발성 골수종 환자에서 형질세포가 30% 이상인 그룹과 이하의 그룹은 유의성을 보이지 않았다. MiR-221은 서구인과 같은 결과를 얻었으며, 다발성 골수종 환자에서 miR-221이 다발성 골수종 환자 진단에 매우 중요한 지표가 될 수 있을 것으로 생각된다. 결론적으로 miR-221은 한국인의 다발성 골수종 진단 또는 예후 지표로 활용할 수 있음을 확인하였다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 추계학술대회(한국공작기계학회)
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• pp.26-31
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• 2001

Recently, miniaturization and mass production are the main trends in manufacturing fields. Therefore, ultraprecision machining and MEMS technology have been taken more and more important position in machining of microparts. Micro endmilling is one of the prominent technology that has wide spectrum of application field ranging from macro parts to micro products, such as PDP and IT components, in precision products manufacturing. However, the deburring is significant problem in making smooth and precise parts in micro endmilling. This paper shows removal characteristics of burr generated by micro endmilling process. Additionally, it is necessary to understand the formation mechanism of burr of micro barrier ribs to find proper deburring method.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.748-751
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• 2003

The electron temperature and plasma density in coplanar alternating-current plasma display panels (AC-PDPs) have been experimentally investigated by a micro Langmuir probe and the high speed discharge images in this experiment.

• 진공이야기
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• 제2권4호
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• pp.9-15
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• 2015

Nonthermal bio-compatible plasma (bioplasma) sources and their characteristics operating at atmospheric pressure could be used for biological cell interactions, especially for plasma bioscience and medicines. The electron temperatures and plasma densities of this bioplasma are measured to be 0.7 ~ 1.8 eV and $(3-5){\times}10^{14-15}cm^{-3}$, respectively. Herein, we introduced general schematic view of the plasma-initiated ultraviolet photolysis of water inside the biological solutions or living tissue for the essential generation mechanism of the reactive hydroxyl radical [OH] and hydrogen peroxide [$H_2O_2$], which may result in apoptotic cell death in plasma bioscience and medicines. Further, we surveyed the various nonthermal bioplasma sources including plasma jet, micro-DBD (dielectric barrier discharge) and nanosecond discharged plasma. The diseased biological protein, cancer, and mutated cells could be treated by these bioplasma sources or bioplasma activated water to result in their apoptosis for new paradigm of plasma bioscience and medicines.

• 열처리공학회지
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• 제17권4호
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• pp.236-240
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• 2004

Effect of plasma power on PECVD process were investigated in this study. TiN and TiCN films were deposited on nitrided STD11 steel with 600W, 1,200W and 1,600W plasma power. As the plasma power was increased, the preferred orientation was reinforced from (200) to (111) and the hardness of films was improved. The low plasma power was, however, effective for improving of adhesion force of films. Regarding above properties, TiN and TiCN films were deposited by gradient plasma power. It was possible to get high hardness as well as adhesion force through gradient plasma power.

• 한국식품영양학회지
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• 제31권2호
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• pp.301-307
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• 2018

In this study, a relatively effective process is used to sterilize Escherichia coli on the surface of micro-sized calcium citrate powder using nitrogen and argon as process gases in a low-temperature vacuum plasma treatment. The purpose of this study is to confirm and to introduce the effectiveness of homogeneous surface treatment for the sterilization of fine inorganic powder by the rotatable low-temperature RF plasma system designed by ourselves. The results of the test using 3M petrifilm showed that there were no remarkable spots in the case of the surface of plasma treated powder, whereas the untreated powder showed many blue spots, which indicating that the E. coli was alive. After 5 days, in the same samples, the blue spots were seen to be larger and darker than before, while the plasma-treated powder showed no changes. The results from FE-SEM analysis showed that the E. coli was damaged and/or destroyed by reactive species generated in the plasma space, resulting in the E. coli being sterilized. Furthermore, the sterilization effects according to the selected parameters ($N_2$ and Ar; flow rate 30 and 50 sccm) adapted in this study were mutually similar, regardless of such different process parameters, and this indicates that homogeneous treatment of powder surfaces could be more effective than conventional methods. Therefore, the plasma apparatus used in this study may be a practical method to use in a powerful sterilization process in powder-type food.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.977-980
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• 1997

Ultraprecision machining process and MEMS technology have been taken more and more important position in machining of micro parts such as PDP and IT components, as the application field of micro parts increases. A micro machining center is very effective equipment for the fabrication of micro parts, because of its benefits such as lower power consumption, high precision and lower machining cost. Therefore, we study the possibility of application to the micro machining of barrier ribs used in PDP and also analyse the machining characteristics. The fabricated barrier rib has 30~$200\mu\textrm{m}$ pitch and was made by the flat endmill with the diameter of 0.2mm, 40, 000rpm condition.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2004년도 유체기계 연구개발 발표회 논문집
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• pp.754-760
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• 2004

The miniaturization and integration are trend of modern blood analyses. Micro-Bio-Fluidics plays an important role in a micro blood analysis system. In this paper, analysis and design technology for blood analysis system is presented. Numerical simulations of a blood flow in micro separator and reservoir are conducted. As a result, we suggest on-chip micro separator, which performed plasma separation from whole blood in micro channels.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1783-1788
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• 2004

In the present paper, a micro flow sensor, which can be used at bio-delivery systems and micro heat pumps, is developed. For this, the micro flow sensor is integrated on a quartz wafer ($SiO_2$) and is manufactured by simple and convenient microfabrication processes. The micro flow sensor aims for measuring mass flow rates in the low range of about $0{\sim}20$ SCCM. The micro flow sensor is composed of temperature sensors, a heater, and a flow microchannel. The temperature sensors and the heater are manufactured by the sputtering processes in this study. In the microfabrication processes, stainless steel masks with different patterns are used to deposit alumel and chromel for temperature sensors and nichrome for the heater on the quartz wafer. The microchannel is made of Polydimethylsiloxane(PDMS) easily. A deposited quartz wafer is bonded to the PDMS microchannel by using the air plasma. Finally, we confirmed the good operation of the present micro flow sensor by measuring flow rate.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1684-1685
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• 2011

This paper presents a theoretical and numerical analysis for thermal isolation of silicon micro-structures, especially for a large size with poor thermal conductivity, as well as straightforward solution for such an issue. Additional metal patterns underneath the silicon structures effectively reduces the thermal isolation. Heat transfer mechanism is analyzed using an equivalent circuit of thermal network including plasma, a heat source, heat capacitors, and thermal resistances. The FEM simulation was carried out to investigate the temperature change of silicon micro-structures according to process time. The temperature of silicon micro-structures with 2 ${\mu}m$ thick chrome layer at a steady state is $86^{\circ}C$, an approximately 40% decrease from the silicon microstructure without thin metal ($122^{\circ}C$)