• Journal of Microbiology and Biotechnology
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• 제12권5호
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• pp.780-786
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• 2002

An immunosensor based on surface plasmon resonance (SPR) with a self-assembled protein G layer was developed for the detection of Escherichia coli O157:H7. A self-assembled protein C layer on a gold (Au) surface was fabricated by adsorbing the mixture of 11-mercaptoundecanoic acid (MUA) and hexanethiol at various molar ratios and by activating chemical binding between free amine (-$NH_2$) of protein G and 11-(MUA) using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDAC) in series. The formation of a self-assembled protein G layer on an Au substrate and the binding of the antibody and antigen in series were confirmed by SPR spectroscopy. The surface morphology analyses of the self-assembled protein G layer on the Au substrate, monoclonal antibody (Mab) against E. coli O157:H7 which was immobilized on protein G, and bound E. coli O157:H7 extracts on Immobilized Mab against E. coii O157:H7 were performed by atomic force microscopy (AFM). The detection limit of the SPR-based immunosensor for E. coli O157:H7 was found to be about $10^4$ cells/ml.

• 정보저장시스템학회:학술대회논문집
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• 정보저장시스템학회 2005년도 추계학술대회 논문집
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• pp.124-127
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• 2005

Rewritable optical memory devices such as an CD-RW and DVD+RW are data storage media, which take advantage of the different optical properties in the amorphous and crystalline states of phase change materials. The switching property, structural transformation, transformation kinetics and chemical bindings of $Ge_xSb_{100-x}$($6{\le}x{\le}$34) were studied to investigate the feasibility of applying $Ge_xSb_{100-x}$ alloys in optical memory. The $Ge_xSb_{100-x}$ thin film was deposited by RF magnetron co-sputtering system and phase change characteristics were investigated by X-ray diffraction (XRD), static tester, inductively coupled plasma atomic emission spectrometer (ICP-AES) and atomic force microscopy (AEM). Optimum fiim composition of $Ge_xSb_{100-x}$ was studied and its minimum time fur laser induced crystallization and optical contrast fur phase transition was performed. These results might be correlated with the binding energies between Ge and Sb, and indicate that $Ge_xSb_{100-x}$ have an potential far optical memory applications.

• JSTS:Journal of Semiconductor Technology and Science
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• 제7권3호
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• pp.151-160
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• 2007

We report the label-free biomolecules detection based on nanomechanical micro cantilevers operated in dynamic mode for detection of two marker proteins (myoglobin and creatin kinase-MB (CK-MB)) of acute myocardical infarctions. When the specific binding between the antigen and its antibody occurred on the fuctionalized microcantilever surface, mechanical response (i.e. resonant frequency) of microcantilevers was changed in lower frequency range. We performed the label-free biomolecules detection of myoglobin and CK-MB antigen in the low concentration (clinical threshold concentration range) as much as 1 ng/ml from measuring the dynamic response change of micro cantilevers caused by the intermolecular force. Moreover, we estimate the surface stress on the dynamic microcantilevers generated by specific antibody-antigen binding. It is suggested that our dynamic microcantilevers may enable one to use the sensitive label-free biomolecules detection for application to the disease diagnosis system based on mechanical immuno-sensor.

• 센서학회지
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• 제22권5호
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• pp.346-351
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• 2013

We developed a one-step method for fabrication of addressable suspended SWNT films and demonstrate excellent detection performance of paraoxon based on OPH-immobilized SWNT films for environmental monitoring. For dispersed SWNT suspension, COOH-SWNT was prepared by the oxidation of carbon nanotubes using acid treatment and sonication. Suspended SWNT-film was fabricated between cantilever electrodes by dielectrophoretic force and surface tension of the water meniscus. After that, OPH were immobilized on suspended SWNT-films by nonspecific binding for enzymatic hydrolysis of paraoxon. The electrical properties of the SWNT films were measured in real time at room temperature. Structurally suspended SWNT films from substrate surface made possible rapid and highly sensitive detection of target molecules with increased convectional and diffusional fluxes of the molecules and with a large binding surface area. SWNT film FET resulted in a real-time, label-free, and electrical detection of paraoxon to the concentration of ca. $10{\mu}m$ with a step-wise rapid response time of several seconds.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1994년도 춘계학술대회 and 제3회 신약개발 연구발표회
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• pp.301-301
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• 1994

〔$^3$H〕Ouabain binding parameters(K$\_$D/ and B$\_$max/,) in homogenates prepared fpom control rat ventricular strip and Langendorff preparations which were not previously exposed to ouabain were compared to those in homogenates from ventricular strip and Langendorff preparations that had been first exposed to a complete ouabain dose-response curve(10$\^$-7/M to 10$\^$-4/ M). In rat ventricular strips and Langendorff perfused rat heart preparations, cumulative dose-response cruves of ouabain revealed biphasic positive inotropic effects, a "low-dose" and a "high-dose" effect with ED$\_$50/ values of 0.5${\mu}$M and 35${\mu}$M ouabain, respectively- The "low-dose" effect in rat ventricular strips disappeared or was diminished significantly when the ouabain dose-response curve wag repeated after the washout of the effects of the first curve, whereas the maximal "high-dose" effect was identical in both exposures to oubain. However, there was no change in the "low-dose" effects in both sets of the Langendorff perfused hearts. The contractile activity of the pre-exposed strips did not indicate the presence of residual ouabain since their basal contractile force was decreased 10% compared to initial control. 〔$^3$H〕Ouabain binding parameters, K$\_$D/ and B$\_$max/, were not changed comparing homogenate of control ventricular strips with that of strips pre-exposed to ouabain. These results suggest that digitalis receptor desensitization in the rat ventricular strip may due to the change of post-receptor events induced by ouabain binding to a high affinity site(${\alpha}$$_2$ isoform).

• 한국자기공명학회논문지
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• 제19권2호
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• pp.67-73
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• 2015

The microcystin is a cyclic heptapeptide from metabolites of cyanobacteria in the genera mycrocystis, anabaeba as a result of eutrophication. It has been known that microcystin-LR is a potent inhibitor of the catalytic subunits of protein phosphatase-1 (PP-1) as well as powerful tumor promoter. The active site of microcystin actually has two metal ions $Fe^{2+}/Zn^{2+}$ close to the nucleophilic portion of PP-1-microcystin complex. We report the isolation and purification of this microcystin-LR from cyanobacteria (blue-green algae) obtained from Daechung Dam in Chung-cheong Do, Korea. Microcystin-LR was extracted from solid-phase extraction (SPE) sample preparation using a CN cartridge. The cyanobacteria extract was purified to obtain microcystin-LR by HPLC method and identified by LC/MS. The detail structural studies that can elucidate the possible role of monovalent and divalent metal ions in PP-1-microcystin complexation were carried out by utilizing molecular dynamics. Conformational changes in metal binding for ligands were monitored by molecular dynamic computation and potential of mean force (PMF) using the method of the free energy perturbation. The microcystin-metal binding PMF simulation results exhibit that microcystin can have very stable binding free energy of -10.95 kcal/mol by adopting the $Mg^{2+}$ ion at broad geometrical distribution of $0.5{\sim}4.5{\AA}$, and show that the $K^+$ ion can form a stable metal complex rather than other monovalent alkali metal ions.

• 인터넷정보학회논문지
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• 제6권5호
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• pp.11-25
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• 2005

최근 PDA나 핸드폰과 같이 제한된 계산능력을 갖는 이동 장치가 증가함에 따라 공개키 암호화 연산을 적용하는 모바일 IPv6 바인딩 갱신 인증 프로토콜에서 모바일 노드의 공개키 연산을 최소화하는 것이 강력히 요구되고 있다. 이를 위해 CAM-DH와 SUCV 같은 기존의 공개키 기반 프로토콜에서는 모바일 노드의 공개키 연산을 흠 에이전트에 위임하는 연산 최적화 옵션을 제공하였다. 그러나 이러한 프로토콜들은 연산 최적화 옵션을 제공하는데 있어서 여러 가지 문제점을 노출하였다. 특히, CAM-DH의 경우 홈 에이전트가 서비스 거부 공격에 취약하며 모바일 노드의 공개키 연산을 완전히 위임받지 못하는 문제점을 갖는다. 본 논문에서는 이러한 CAM-DH의 문제점을 개선하며 또한 Aura의 이중 해쉬 기법을 통해 CAM-DH에서 적용하는 CGA의 보안성을 강화시킨다. CAM-DH와의 비교를 통해 개선된 프로토콜이 모바일 노드의 계산 비용을 최소화하고 강화된 보안성과 향상된 관리능력을 제공함을 알 수 있다.

• 대한의생명과학회지
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• 제13권1호
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• pp.1-10
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• 2007

Nebulin, a giant modular protein from muscle, is thought to act as molecular ruler in sarcomere assembly. In skeletal muscle, the C-terminal ${\sim}50 kDa$ region of nebulin extends into the Z-line lattice. The most recent studies implicated highlighting its extensive isoform diversity and exciting reports revealed its expression in cardiac and non-muscle tissues containing brain. Also these novel findings are indicating that nebulin is actually a multifunctional filament system, perhaps playing roles in signal transduction, contractile regulation, and myofibril force generation, as well as other not yet defined functions. However the binding protein of nebulin and function in brain is still unknown. A novel binding partner of nebulin C-terminal region was identified by screening a human brain cDNA library using yeast two-hybrid system. Nebulin C-terminus binding protein 51 (NCBP51) was contained a RING-finger domain and identified a new isoform of RING finger protein 125 (RNF125). The interaction was confirmed using the GST pull-down assay. NCBP51 belongs to a family of the RING finger proteins and its function remains to be identified in brain. The role of nebulin and NCBP51 will be studied by loss-of-function using siRNA technique in brain.

• 한국구조물진단유지관리공학회 논문집
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• 제26권5호
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• pp.119-126
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• 2022

본 연구는 내진설계가 되어 있지 않은 필로티 건축물의 부족한 횡력을 보강할 수 있는 외부부착형 내진보강공법(Binding Column Method, BCM)을 제안하였다. 또한, 제안된 내진보강공법을 대상으로 보강실험체 4개, 기준 실험체 1개를 제작하여 반복가력 실험을 통하여 보강 전·후의 내진성능향상 효과를 검토하였다. 실험 결과, 기준 실험체(SC1)는 급격한 강도저하와 함께 취성적인 전단파괴의 양상을 나타낸 반면, BCM 공법을 적용한 실험체(SC2, SC3, SC4, SC5)는 강도 및 강성의 증가와 함께 에너지 흡수 능력이 큰 타원형의 이력특성을 나타내었다. 또한, 간격이 좁고 토크가 크며, L자형 강판의 두께가 두꺼울수록 보강효과가 향상됨을 알 수 있다. BCM공법 중 전단보강간격이 작고, 조임력 값이 크며, 연결철물이 두꺼운 SC4실험체가 가장 뛰어난 내진성능보강 효과를 나타내었다.

• 폴리머
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• 제30권4호
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• pp.279-285
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• 2006

유전자 치료에 있어서 안전성의 장점을 지니고 있는 비바이러스성 전달체에 대한 관심도가 높아져가고 있다. 비바이러스성 전달체 중, 양이온성 리포좀이나 합성 유전자 전달체는 in vitro계에서 효율적인 DNA 전달체이지만, 낮은 생체적합성으로 인하여 in vivo 계에서의 응용성은 크게 뒤떨어지고 있다. 한편, 천연 양이온성 다당류인 키토산은 낮은 독성과 강한 양전하를 띠고 있어 유전자 전달 시스템 (gene delivery system)에 있어 아주 기대되는 전달체이다. 본 연구에서는 저분자량 수용성 키토산 (low molecular water-soluble chitosan ; LMWSC)을 이용하여 동맥 벽 세포를 표적할 수 있는 표적성 유전자 전달체를 합성하였다. 상대 점도와 Kina 적정법을 이용하여 LMWSC의 점도 평균 분자량 $(M_W)$과 탈아세틸화도 (degree of de acetylation ; DDA)를 측정하였고 구조는 FTIR, $^1H-NMR$, 그리고 $^{13}C-NMR$을 통하여 분석하였다. 동맥 벽을 표적하기 위한 유전자 전달체로서 pegylated LMWSC 의 말단에 특이성 세포 표적 펩타이드인 artery wall binding peptide (AWBP)를 결합시킴으로써 AWBP-PEG-g-LMWSC을 합성하였고 FTIR, $^1H-NMR$. zeta potentiometer. 그리고 atomic force microscopy (AFM)을 이용하여 분석하였다.