• Resources Recycling
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• v.12 no.6
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• pp.3-7
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• 2003

For the manufacture of iron oxide, the hydro-process and the pyre-process are conventionally used. Both processes use a huge amount of chemicals in reaction which affect the environment harmfully. This paper introduced the new environment friendly processes; the bio-chemical process and the self propagating high temperature synthesis process.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.239-240
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• 2004

작년 2월에 착공식을 가진 월성의 WTRF (Wolsung Tritium Removal Facility)에서 2005년 후반기부터 매년 $2.6{\times}10^{16}$ Bq(7 MCi) 이상의 삼중수소가 생산될 예정이므로 이제 우리나라에서도 삼중수소를 활용하는 연구를 본격적으로 할 수 있게 되었다. 현재 우리나라는 삼중수소를 전량, 수입하여 37 MBq (1 mCi) 혹은 $3.7{\times}10^{10}$ Bq (1 Ci)미만의 매우 적은 양으로 생물, 생화학, 농학 및 의약품 합성연구 등의 연구에 이용하오 있는 정도이고, 삼중수소의 활용에 관한 국내의 연구는 거의 전무한 상태이다.(중략)

• The Microorganisms and Industry
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• v.15 no.2
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• pp.46-49
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• 1989

단백질의 아미노산 서열에 변화를 줄려고 할 때 대상단백질의 3차구조에 대한 충분한 정보가 있고 시험해 보고자 하는 가설이 확실할 때에는 특정잔기를 다른 특정잔기로 치환시켜 효능을 전환시키는 것이 효과적이겠고, 3차구조가 안밝혀져 있거나 어떻게 치환해야 할지 모를 경우에는 무작위 변이유도법과 세포에 의한 형질선별법이 바람직하다 하겠다. 이러한 관점에서 볼 때 유전자 재조합기법을 통한 신물질창출을 성공적으로 수행하기 위해서는 유전자 조작기술과 단백질 분석기술은 물론 단백질생화학, 분자유전학, 미생물생리학 등에 대한 충분한 이해를 바탕으로하여 여러 분야에서 협동적으로 연구되어야 하겠다.

• Applied Chemistry for Engineering
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• v.34 no.2
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• pp.121-125
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• 2023

Casein is a milk protein and one of the most important nutrients in milk. The composition is over 80% in cow's milk and about 20~45% in human's milk. Casein is highly biocompatible and biodegradable, so it has been studied for various biomedical materials applications as well as drug delivery systems. It is widely known that casein can be prepared as nanoparticles in the presence of the Ca²⁺ metal ion. Because casein is amphiphilic, hydrophobic drugs could be loaded inside to form a protein-based drug delivery system. In this study, we studied the optimum conditions for casein nanoparticle formation using natural metal ions present in the body, such as calcium, magnesium, zinc, and iron. It was confirmed that nanoparticles have a uniform size of around 150 nm and negative zeta potential values. In addition, it was demonstrated that casein nanoparticles have a cell viability of more than 80% and efficient intracellular uptake properties using confocal microscopy. From the results, it was also shown that the casein nanoparticles prepared using various metal ions have the potential to be biocompatible drug delivery carriers.

• Journal of Life Science
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• v.16 no.1
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• pp.168-174
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• 2006

Enantiopure epoxides are valuable intermediates for the asymmetric synthesis of enantiopure bioactive compounds. Microbial epoxide hydrolases (EHs) are versatile biocatalysts for the preparation of enantiopure epoxides by enantioselective hydrolysis of cheap and easily available racemic epoxide substrates. EHs are commercially potential biocatalysts due to their characteristics such as high enantioselectivity, cofactor-independent catalysis, and easy-to-prepare catalysts. In this paper, recent progresses In molecular engineering of EHs are reviewed to evaluate the commercial feasibility of EH-catalyzed hydrolytic kinetic resolution for the production of enantiopure epoxides.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.127-127
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• 2014

인체 내 소량의 생체성분(혈액, 소변 등)을 감지하는 바이오센서 기술은 질병 진단뿐만 아니라 예방 및 관리로 의료서비스 확대, 개인 맞춤형 진료 및 의료비 감소 효과를 가져올 수 있는 기술이다. 광바이오센서는 광학적인 측정방법을 이용하여 다양한 생화학물질들의 상호 반응을 검출해 낼 수 있는 바이오센서로 현재 활발하게 연구가 진행되고 있다. 광 바이오센서는 생체성분 내에 존재하는 전하를 가진 많은 이온들 및 Salt 농도 등에 영향을 받지 않기 때문에 나노 와이어를 이용한 FET (field-effect transistor)형 바이오센서에 비해 많은 장점을 가지고 있다. 일반적으로 광 바이오센서는 형광물질, 인광물질, 발색물질, 방사선 물질 등의 발광물질을 인식물질에 표지하여 인식물질과 분석물질과의 반응유무를 표지된 발광물질의 광학 신호를 감지하여 분석물질을 검출해내는 표지식 광 바이오센서 기술이 상용화되고 있다. 그러나 이러한 분석 방법은 민감도는 우수하지만 분석 시간이 매우 느리고, 고가의 분석 장비 및 복잡한 제조 공정 등의 단점들을 가지고 있다. 이러한 단점들을 극복하기 위하여 생화학 반응 유무를 표지물질 없이 광학적 방식으로 직접 측정할 수 있는 비표지식 광 바이오센서 기술이 최근 들어 많이 연구되고 있다. 본 논문에서는 광파장 이하의 주기를 가진 주기적 공진 격자 표면에서 일어나는 바이오 항원-항체 반응에 대한 공진 반사 파장을 측정하여 생체성분 내에 존재하는 바이오 항원을 고감도로 검출할 수 있는 비표지식 공진반사광 바이오센서 기술을 소개하고자 한다. 공진반사광 바이오센서를 이용하여 human serum내에 존재하는 심근경색 마커인 troponin I (cTnI), creatine kinase MB (CK-MB), myoglobin (MYO)을 0.1 ng/mL 이하의 농도까지 고감도로 측정할 수 있었다.

• Applied Chemistry for Engineering
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• v.9 no.3
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• pp.430-434
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• 1998

Preparative HPLC (High-Performance Liquid Chromatography) is mainly used for separating useful component from biological samples. By reversed-phase HPLC packed with preparative packings ($15{\mu}m$), the adsorption characteristics with sample size were investigated. Sample was 5'-GMP, a flavor enhancer, and the composition of mobile phase was 20mM $KH_2PO_4$ solution:methanol (97:3 vol.%). From the experimental results, the effect of sample size on retention factor was negligible, but the peak was asymmetrical above $1{\mu}g$ of sample. In addition, the increase in sample size deteriorated the number of theoretical plates, and at small concentration, the number of theoretical plates was less because of large peak width. In the experimental condition, the adsorption isotherm of 5'-GMP was relatively well represented by Freundlich equation.

• KSBB Journal
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• v.17 no.4
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• pp.321-325
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• 2002

Chiral epoxides are valuable intermediates for the asymmetric synthesis of enantiopure bioactive compounds. Microbial epoxide hydrolases (EHs) are newly discovered enzymes and versatile biocatalysts for the preparation of chiral epoxides by enantioselective hydrolysis of cheap and easily available racemic epoxide substrates. EHs are commercially potential biocatalysts due to their characteristics such as high enantioselectivity, cofactor-independent catalysis, and easy-to-Prepare catalysts. In this Paper, recent progresses in biochemistry and molecular biology of EH and developments of novel reaction systems are reviewed to evaluate the commercial feasibility of EH-catalyzed hydrolytic kinetic resolution for the production of chiral epoxides.

• Journal of Sensor Science and Technology
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• v.6 no.3
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• pp.214-220
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• 1997

A thin film optical waveguide sensor has been developed to measure and analyze quantitatively some inherent optical properties of biochemical substances. In this paper, two different kinds of thickness of thin film waveguide were prepared by RF sputtering of Corning-7059 glass(n = 1.588 at ${\lambda}=\;514nm$, Ar laser) on Pyrex glass substrates. We made a sensing membrane coated on the thin film waveguide with the poly(vinyl chloride-co-vinyl acetate-co-vinyl alcohol) (91 : 3 : 6) copolymer membrane based on $H^{+}$-selective chromoionophore and $K^{+}$-selective neutral ionophore and then proposed the thin film opptical waveguide ion sensor which can select a potassium ion. This sensor based ell the absorbance change by utilizing chromoionophore and neutral ionophore, which changes their absorption spectrum in the UV-vis region upon complexation of the corresponding ionic species, have been reported. The sensitivity dependence of the proposed sensor on interaction length, waveguide thickness, and content of a chromoionophore was investigated. This sensor has the measurement range of $10^{-6}M{\sim}1M$ for $K^{+}$ concentration and 90% response time of duration within 1 min. Also, our thin film optical waveguide sensor using the evanescent field was investigated as compared with conventional transmission sensor or optode sensor by the optical fiber. The sensitivity of thin-film waveguide $K^{+}$ sensor is higher than that of the conventional transmission sensor. The proposed sensor is expected to be useful to biochemical, medical, environmental inspection and so on.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.417-424
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• 2019

Despite its superior ability to show distinct cellular morphology and for long-term storage, conventional tissue fixation by formalin has many drawback, including slower fixation, the exposure to harmful chemicals and extensive protein modification. Herein, we assessed the effects of rapid microwave-assisted tissue fixation on histological examination and on protein integrity by comparing these microwave irradiation fixated tissues with the formalin-fixed tissues. One of the paired mouse tissues (liver and kidney) was fixed in formalin and the other was fixed by using microwave irradiation in phosphate buffered saline. Each slide from the paraffin-embedded tissues was examined by H & E staining for the adequacy of fixation and by immunohistochemical staining for antigenicity in a blinded fashion. Evaluation of protein recovery and the protein quality from the fixed tissues were analyzed by the BCA method and Western blotting, respectively. The results from H & E staining and immunohistochemical staining showed that the sections obtained from microwave-fixed tissues under our experimental conditions were comparable to those of the formalin-fixed tissues except for the integrity of RBCs. Furthermore, proteins were effectively extracted from the microwave-fixed tissues with acceptable preservation of the proteins' quality. Taken together, this microwave-assisted tissue processing yields a quick fixation and better protein recovery in higher amounts, as well as the adequacy of fixation and the antigenicity being comparable to formalin-fixed tissues, and this all suggests that this new fixation technique can be applied in an environment where rapid tissue fixation is required.