• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.3
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• pp.561-565
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• 2007

We propose glass and PDMS (polydimethylsiloxane) chips for DNA amplification with continuous-flow PCR (polymerase chain reaction). The PDMS microchannel was fabricated using a negative molding method for sample injection. Three heaters and sensors of ITO (indium-tin-oxide) thin films were fabricated on glass chip. ITO heaters and sensors were calibrated accurately for the temperature control of the liquid flow. ITO heater generated stable heat versus applied power. ITO sensor resistance was changed linearly versus temperature increase as a RTD (resistance temperature detector) sensor. As a result, we enable precision temperature control of continuous-flow PCR chip. Using the continuous-flow PCR chip DNA plasmid pKS-GFP 720 bp was successfully amplified.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.59-60
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• 2011

본 논문에서는 기존의 PCR 장비가 가지고 있는 낮은 경제성, 장비의 대형화, 긴 분석 시간 등과 같은 단점을 해결하기 위하여 ATMEGA128 마이크로 칩을 사용 continuous-flow PCR 칩의 온도를 제어 하였다. Polydimethylsiloxane (PDMS)와 산화 인듐-주석(Indium tin-oxide, ITO) 유리 기판을 사용하여 continuous-flow PCR 칩을 제작하였고 PDMS를 주조 하여 마이크로 채널을 형성하였다. 또한 유리 기판위에 ITO 전극을 패터닝하여 마이크로 히터를 제작하였다. 이 결과 continuous-flow PCR 칩에서 빠르고 정확한 온도 제어를 통한 DNA 중합 효소 연쇄반응 결과를 얻을 수 있었다.

• 유체기계공업학회:학술대회논문집
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• 2003.12a
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• pp.115-120
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• 2003

In this work, a continuous-flow micro-PCR system is systematically designed. From the numerical simulation based on the finite volume method, adapting oneself to a new environmental temperature without an external temperature controller is shown to be possible and a cooler as well as a heater is shown to be necessary to obtain three individual temperature zones for polymerase chain reaction. In addition, appropriate geometry of a heat sink for the cooler is determined by using a compact modeling method, the porous medium approach.

• Journal of Environmental Health Sciences
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• v.22 no.1
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• pp.57-64
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• 1996

The main objectives of this research program were to study the ozonation characteristics of phenol wastewater in the continuous packed colamn reactor(PCR) and the bubble column reactor (BCR) using ozone and to provide the fundamentals of ozonizing the phenol wastewater. Among various influencing factors that affect on phenol decomposition through the oxidation by ozone, contacting method, and ozone flow rate were chosen as reaction parameters. The results were obtained from two different types of contacting methods where the countercurrent flow was more efficient than the cocurrent flow in both the phenol removal efficiency and the ozone utilization efficiency. Furthermore, PCR showed the phenol removal efficiency 1.6 to 3% higher than that of BCR in both contacting methods, as well as the ozone utilization efficiency, suggesting that the countercurrent flow is more efficient than the cocurrent flow. The phenol removal efficiency and the ozone utilization efficiency were reduced in both reactors as the influent ozone flow rate increased. Upon varing flow rate from 0.5l/min to 2.0 l/min by 0.5 l/min, the phenol removal efficiency was reduced approximately from 8.5% to 10.5% and the ozone utilization efficiency was reduced approximately from 6% to 8% in both reactors. The performance of PCR was superior to that of BCR in the aspects of phenol removal and ozone utilization efficiency.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1386-1387
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• 2006

PDMS와 ITO 유리를 이용하여 continuous-flow PCR chip을 제작하였다. PDMS를 이용하여 microchannel을 형성하여 주었고, ITO electrode를 heater와 sensor로 사용하기 위하여 반도체 공정을 통해 패턴을 형성하였다. microchannel내에 흐르는 시료의 온도를 제어하기 위하여 heater와 sensor를 calibration을 하였다. ITO heater는 인가된 전압에 대해 매우 선형적인 발열을 하였으며, ITO sensor는 온도에 대해 선형적인 저항 변화를 나타낸 바, 그 결과 continuous-flow PCR chip의 정확한 온도 제어가 가능하였다.

• 연구논문집
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• s.33
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• pp.17-25
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• 2003

In this work, thermal design of a PCR chip for LOC is systematically conducted. From the numerical simulation of a PCR chip based on the finite volume method, how to control the average temperature of a PCR chip and the temperature difference between the denaturation zone and the annealing zone is presented. The average temperature is shown to be controlled by adjusting heat input and a cooler as well as a heater is shown to be necessary to obtain three individual temperature zones for polymerase chain reaction. To reduce the time required, a heat sink for the cooler is not included in the calculation domain for the PCR chip and heat sink design is conducted separately by using a compact modeling method, the porous medium approach.

• Journal of Society of Preventive Korean Medicine
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• v.22 no.1
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• pp.107-127
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• 2018

Objectives : The present study investigated the anti-obese and blood flow improvement activities of aqueous extracts of ginseng berry (GBe) on the mild diabetic obese mice as compared with metformin. Methods : After end of 56 days of continuous oral administrations of GBe 150, 100 and 50 mg/kg, or metformin 250 mg/kg, anti-obese and blood flow improvement effects - the changes of body weights, body and abdominal fat density by in live dual-energy x-ray absorptionmetry (DEXA), tail bleeding time, prothrombin time (PT), activated partial thromboplastin time (aPTT), serum total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL) and high density lipoprotein (HDL) levels, aorta and serum cyclic guanosine monophosphate (cGMP), nitric oxide (NO) and endothelin (ET)-1 levels, aorta phosphorylated PI3K (pPI3K), phosphorylated Akt (pAkt) and phosphorylated p38 MAPK (pp38 MAPK) levels were systemically analyzed. In addition, aorta vascular dilation and constriction related gene mRNA expressions - PI3K, Akt, eNOS, p38 MAPK and ET-1 were also analyzed by realtime RT-PCR. Results : The obesity and related blood flow impairment, induced by 84 days of continuous HFD supply, were significantly inhibited by 56 days of continuous oral treatment of GBe 150, 100 and 50mg/kg, dose-dependently, and they also dramatically normalized the changes of the aorta vascular dilation and constriction related gene mRNA expressions, also dose-dependently. Especially, GBe 150 mg/kg constantly showed favorable inhibitory activities against type II diabetes related obesity and vascular disorders through PI3K/Akt pathway and p38 MAPK mediated cGMP, NO and ET-1 expression modulatory activities, as comparable to those of metformin 250 mg/kg in HFD mice. Conclusion : By assessing the key parameters for anti-obese and blood flow improvement activities on the HFD-induced mild diabetic obese mice, the present work demonstrated that GBe 150, 100 and 50 mg/kg showed favorable anti-obese and blood flow improvement effects in HFD-induced type II diabetic mice, through PI3K/Akt pathway and p38 MAPK mediated cGMP, NO and ET-1 expression modulatory activities.

• Journal of the Korean Society of Visualization
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• v.14 no.1
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• pp.57-61
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• 2016

We report a finding of fast(exceeding 2,000 K/s) heating of polydimethylsiloxane(PDMS), one of the most commonly-used microchannel materials, under cyclic loadings at high(~MHz) frequencies. A microheater was created based on the finding. The heating mechanism utilized vibration damping of sound waves, which were generated and precisely manipulated using a conventional surface acoustic wave(SAW) microfluidic system, in PDMS. The penetration depths were measured to range from $210{\mu}m$ to $1290{\mu}m$, enough to cover most microchannel heights in microfluidic systems. The energy conversion efficiency was SAW frequency-dependent and measured to be the highest at around 30 MHz. Independent actuation of each interdigital transducer(IDT) enabled independent manipulation of SAWs, permitting spatiotemporal control of temperature on the microchip. All the advantages of this microheater facilitated a two-step continuous flow polymerase chain reaction(CFPCR) to achieve the billion-fold amplification of a 134 bp DNA amplicon in less than 3 min. In addition, a technique was developed for establishing dynamic free-form temperature gradients(TGs) in PDMS as well as in gases in contact with the PDMS.

• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.2
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• pp.110-117
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• 2000

Relationship between monoclonal antibody (MAb) productivity and growth rate, and effects of high cell density on MAb production rate increased with increasing specifis growth rate in both suspended and immobilized continuous cultures indicate a positively growth-associated relationship between MAb productivity and growth rate. moreover, the specific production rate was higher in the immobilized cell culture than that in suspended one at all dilution rates. In order to clarify these phenomana, MAb mPNA experession and cell cycle distribution were investigated in bacth cultures with immobilized cells and suspended cells. RT-PCR was used for observation of MAb mRNA expression and a two-color bromodeoxyuridine (BrdU)/propidium iodide (PI) flow cytometry method for determination of cell cycle distribution. The results revealed that MAb nRNA expression until dead phase, which was longer than in suspended cell. The cell cycle distribution patterns were observed almost the same for both immobilized and suspended cells. Such results may imply that a high cell density state has positive influence on the mRNA expression and on growth-associated Mab productivity of T0405 cells.

• KSBB Journal
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• v.15 no.1
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• pp.88-95
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• 2000

We have produced new-structured oligosaccharides using immoobilized mixed-enzyme reactor of destransucrase from Leuconostoc mesenteroides B-512FMCM and $\alpha$-amylase from Aspergillus oryzae. The reactors of immobilized mixed-exzyme beads were more efficient for the production of oligosaccharides than that of each immobilized enzyme bead in stirred-tank reactior(STR) or in packed-bed reactor(PCR). In continuous flow reactor, the immobilized mixed-enzyme bead in PBR was more stable than in STR, and 52% of initial yield was maintained for 200 hr. New structured-oligosaccharides (NOS) reduced the change of pH in the culture of Streptococcus mutans. It also showed an inhibitory effect on the growth of Staphylococcus aureus.