• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1988-1990
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• 2002

마이크로 바이오칩용 미세 무게 감지 소자를 개발하기 위해 통상적인 MEMS 공정에 PZT sol solution을 함침하여 binder로서 적용하는 복합적인 스크린 인쇄 방법을 적용해 $800-850^{\circ}C}$의 비교적 저온에서 높은 소결밀도와 우수한 전기적인 특성을 가지는 PZT-0.12PCW 후막 구동형 캔틸레버 소자를 Pt/$TiO_2$/YSZ/$SiO_2$/Si 기판에 제조하였다. 제조된 PZT-0.12PCW 후막 구동형 캔틸레버 소자의 공진 주파수와 변위를 레이저 미소 변위 측정 시스템을 이용하여 공기 중 및 액체 중에서 측정함으로써 캔틸레버 크기에 따른 공진 특성 변화, 액체 내에서의 댐핑 효과 등을 분석할 수 있었다. 또한 Au를 증착하거나biotin-streptoavidin 반응을 통해 단백질을 고정화시켜 무게변화를 야기시킨 후 소자의 감도를 평가함으로써 PZT-0.12PCW 후막 구동형 캔틸레버를 우수한 성능의 바이오칩용 미세 무게 감지 소자로 응용할 수 있음을 알 수 있었다.

• Journal of Microbiology and Biotechnology
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• v.14 no.4
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• pp.783-788
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• 2004

Marker proteins of genetically-modified organisms (GMO) and their antibodies were prepared and characterized as major components of an analytical system. We selected two GMO markers, neomycin phosphotransferase II and 5- enolpyruvylshikimate-3-phosphate synthase, and produced them from E. coli employing genetic recombination technology. After purification, their structural conformation and binding affinities to the respective antibodies were characterized. The results showed that the recombinant proteins were identical with commercially obtained reference proteins. We further used them as immunogens to raise polyclonal antibodies capable of discriminating GMO containing protein from non-GMO. Well-characterized marker proteins and antibodies will be valuable as immunoreagents in constructing analytical systems such as biosensors and biochips to measure quantities of GMO.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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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.

• Molecules and Cells
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• v.22 no.3
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• pp.254-261
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• 2006

DNA microarray is a powerful tool for high-throughput analysis of biological systems. Various computational tools have been created to facilitate the analysis of the large volume of data produced in DNA microarray experiments. Normalization is a critical step for obtaining data that are reliable and usable for subsequent analysis such as identification of differentially expressed genes and clustering. A variety of normalization methods have been proposed over the past few years, but no methods are still perfect. Various assumptions are often taken in the process of normalization. Therefore, the knowledge of underlying assumption and principle of normalization would be helpful for the correct analysis of microarray data. We present a review of normalization techniques from single-labeled platforms such as the Affymetrix GeneChip array to dual-labeled platforms like spotted array focusing on their principles and assumptions.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.5
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• pp.111-116
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• 2018

Thermal fusion bonding is a method to enclose open microchannels fabricated on polymer chips for use in lab-on-a-chip (LOC) devices. Polymethyl methacrylate (PMMA) is utilized in various biomedical-microelectromechanical systems (bio-MEMS) applications, such as medical diagnostic kits, biosensors, and drug delivery systems. These applications utilize PMMAs biochemical compatibility, optical transparency, and mold characteristics. In this paper, we elucidate both the conformational entanglement of PMMA molecules at the contact interfacial regime, and the qualitative nature of the thermal fusion bonding phenomena through systematic molecular dynamics simulations.

• Clinical and Experimental Pediatrics
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• v.48 no.7
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• pp.779-788
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• 2005

Purpose : Echinacea, a traditional plant medicine has been used as immune-stimulant. Recent studies have revealed that extract of Echinacea has immunostimulatory effects on human blood mononuclear cells. This study was designed for the purpose of screening the genes associated with immunologic effects of Echinacea on monocytes and dendritic cells using a cDNA microarray chip. Methods : $CD14^+$ monocyte cells were cultured for one day with Echinacea extract(final concentration : $50{\mu}g/mL$) in experiment 1, but were cultured without Echinacea in experiment 2. The gene expression of these cultured monocytes was analyzed using the cDNA microarray chip. Dendritic cells produced from $CD14^+$ monocyte were cultured for five days with GM-CSF and IL-4, and then cultured for one day with Echinacea in experiment 3, but were done without Echinacea in experiment 4. Results : In experiments 1 and 2, there were 17 significantly expressed genes with average expression ratios above 2.5, including interferon gamma-inducible protein 30(IFI 30), CDC(cell-division-cylcle)-like kinase 2(CLK 2), syndecan binding protein(syntenin), superoxide dismutase 2, etc. In experiments 3 and 4, there were 24 gene, with significantly expressed genes were 24 genes, which were insulin-like growth factor 2(somatomedin A), methyl-CpG binding domain protein 3, IFI 30, small inducible cytokine subfamily A, member 22, etc. The genes encoding CD44, IFI 30, mannose receptor C type 1(MRC 1), chemokine receptor 7(CCR 7), CLK 2, syntenin and cytochrome C oxidase subunit VIII were significantly expressed in both monocytes and dendritic cells cultured with Echinacea. Conclusion : This study employed a cDNA microarray chip to elicit the immune-associated gene profile; the expression was enhanced by Echinacea in CD14+ monocytes and dendritic cells. Thus we laid the basis for the quantitative and functional analysis of genes induced by Echinacea in monocytes and monocyte-derived dendritic cells.

• Journal of Bio-Environment Control
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• v.31 no.4
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• pp.292-299
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• 2022

This study was conducted to analyze physical and chemical properties of horticultural substrates and response of hydroponically grown two cultivars of 'Namcheon' and 'Somirang' perilla by four different substrates: coir (chip:dust = 5:5), perlite, granular rockwool, and commercial mixed substrate (cocopeat:peatmoss:vermiculite:perlite: zeolite = 50:25:10:10:5). There were no significant differences in EC and pH according to substrates. Container capacity was the greatest in granular rockwool, and it showed appropriate levels in mixed substrate and coir. Air space was higher in coir and perlite than the other treatments. Bulky density reached a proper standard in all substrates excepting coir. The leaf length and width of 'Namcheon' indicated the most in mixed substrate, though the value of 'Somirang'was greatest in coir substrate. The leaf weight of both cultivars was highest in mixed substrate, and relatively low in coir and perlite. The total yield of leaves was separated by two groups: higher group, which are mixed substrate and granular rockwool, and lower group, which are coir and perlite. There was a large gap by 28% between these two groups. Therefore, this study suggests that substrates with high water holding capacity such as mixed substrate or granular rockwool are most suitable for the hydroponic cultivation of perilla, which require sufficient moisture supply to the root zone.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.7 no.2
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• pp.13-18
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• 2013

In this paper design a 8 bit Current Steering D/A Converter for stimulating neuron signal. Proposed circuit in paper shows the conversion rate of 10KS/s and the power supply of 3.3V with 0.35um Magna chip CMOS process using full custom layout design. It employes segmented structure which consists of 3bit thermometer decoders and 5bit binary decoder for decreasing glitch noise and increasing resolution. So glitch energy is down by $10nV{\bullet}sec$ rather than binary weighted type DAC. And it makes use of low power current stimulator because of low LSB current. And it can make biphasic signal by connecting with Micro Controller Unit which controls period and amplitude of signal. As result of measurement INL is +0.56/-0.38 LSB and DNL is +0.3/-0.4 LSB. It shows great linearity. Power dissipation is 6mW.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.10
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• pp.4814-4821
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• 2012

An e-passport is equipped with bio information by adding the non-attachable IC chip with a smart function. In order to solve such a problem, the user's privacy is protected by using the BAC, PA, AA and EAC mechanisms. However, the password key used in the BAC mechanism is made of the combination of the MRZ values. As a result, it is possible to decode the password by using the indiscriminate attacking program after finding out the combined rules of MRZ. This thesis suggests the mechanism with an improved level of efficiency through the time-stamp values by using the information of images and fingerprints and checking the forge or falsification of the e-passport when establishing a safe channel between the chip of the e-passport and the decoding system.

• Applied Chemistry for Engineering
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• v.29 no.6
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• pp.645-651
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• 2018

Lung cancer has the highest death rate of any cancer diseases in Koreans. However, patients often feel difficult to recognize their disease before facing the terminal diagnosis due to the absence of any significant symptoms. Furthermore, the clear detection of an early cancer stage is usually obscure with existing diagnostic methods. For this reason, extensive research efforts have been made on introducing a wide range of biochemical diagnostic tools for the molecular level analysis of biological fluids for lung cancer diagnoses. A chip-based biosensor, one type of the analytical devices, can be a great potential for the diagnosis, which can be used without any further expensive analytical equipments nor skilled analysts. In this mini review, we highlight recent research trends on searching biomarker candidates and bio-chip sensors for lung cancer diagnosis in addition to discussing their future aspects.