• Title/Summary/Keyword: SPR

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Detection of Methanol concentration using SPR (표면 프라즈몬 현상을 이용한 메탄올의 농도 측정)

  • 도용화;이관수;박선택;송석호;오차환;김필수
    • Proceedings of the Optical Society of Korea Conference
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    • 2001.02a
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    • pp.106-107
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    • 2001
  • 표면 플라즈몬 공명(SPR:Surface Plasmon Resonance) 현상은 금속이나 유전체 박막의 두께 및 광학계수 등의 측정이나 센서로 주로 응용되어 왔다. 특히, 최근에는 SPR을 이용한 광 센서나 광 변조기, 파장필터, 광 스위치 등의 광소자에 대한 연구가 많이 되고 있다 본 논문에서는 액체의 농도에 따라 유전 상수가 변하는 것을 이용하여 SPR 광센서가 가능함을 보였다. (중략)

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Characteristics of Protein G-modified BioFET

  • Sohn, Young-Soo
    • Journal of Sensor Science and Technology
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    • v.20 no.4
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    • pp.226-229
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    • 2011
  • Label-free detection of biomolecular interactions was performed using BioFET(Biologically sensitive Field-Effect Transistor) and SPR(Surface Plasmon Resonance). Qualitative information on the immobilization of an anti-IgG and antibody-antigen interaction was gained using the SPR analysis system. The BioFET was used to explore the pI value of the protein and to monitor biomolecular interactions which caused an effective charge change at the gate surface resulting in a drain current change. The results show that the BioFET can be a useful monitoring tool for biomolecular interactions and is complimentary to the SPR system.

Overproduction of Streptomyces griseus Protease A and B Induces Morphological Changes in Streptomyces lividans

  • Chi, Won-Jae;Kim, Jung-Mee;Choi, Si-Sun;Kang, Dae-Kyung;Hong, Soon-Kwang
    • Journal of Microbiology and Biotechnology
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    • v.11 no.6
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    • pp.1077-1086
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    • 2001
  • The sprA and sprB gene encoding chymotrypsin-like proteases Streptomyces griseus protease A (SGPA) and Streptomyces griseus protease B (SGPB) and the sprT gene that encodes Streptomyces griseus trypsin (SGT) were cloned from Streptomyces griseus ATCC10137 and overexpressed in Streptomyces lividans TK24 as a heterologous host. The chymotrypsin activity of tole culture broth measured with the artificial chromogenic substrate , N-succinyl-ala-ala-pro-phe-p-nitroanilide, was 10, 14 and 14 units/mg in the transformants haboring the sprA, sprB and sprD genes, respectively. The growth of S. lividans reached the maximum cell mass after 4 days of culture, yet SGPA and SGPD production started in the stationary phase of cell growth and kept increasing for up to 10 days of culture in an R2YE medium. The trypsin activity of the culture broth measured with the artificial chromogenic substrate , N-${\alpha}$-benzoyl-DL- arginine-p-nitroanilide , was 16 units/mg and SGT production started in the stationary phase of cell growth and kept increasing for up to 10 days of culture in an R2YE medium. The introduction of the sprA gene into S, lividans TK24 triggered the biosynthesis of pigmented antibiotics, actinorhodin and undecylprodigiosin, and induced significant morphological changes in the colonies in Benedict, R2YE, and R1R2 media. In addition, the introduction of the sprT gene also induced morphological changes in the colony shape without affecting the antibiotic production, thereby implying that certain proteases would appear to play very important and specific roles in secondary-metabolites formation and morphological differentiation in Streptomyces.

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Effects of Lonicerae Caulis (LC) on Allergic Contact Dermatitis (ACD) induced by DNCB in mice (인동등(忍冬藤)이 DNCB로 유발된 알레르기성 접촉피부염에 미치는 영향)

  • Lee, Yu-Jin;Lee, Ho-Chan;Choi, Jung-Hwa;Kim, Jong-Han;Park, Soo-Yeon
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.30 no.3
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    • pp.46-61
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    • 2017
  • Objectives : Allergic contact dermatitis(ACD) is a type IV delayed hypersensitivity reaction that results from cumulative exposures and subsequent sensitization to an environmental chemical. Lonicerae Caulis(LC) can clear away heat and relieve toxin, disperse wind and heat, dredge the channel. The present study was designed to investigate the effects of LC on allergic contact dermatitis(ACD) induced by 2,4-dinitrochlorobenzene(DNCB) in mice. Methods : In this experiment, the effects of LC on changes in body weights, ear and dorsum skin thicknesses, ear weights, clinical aspects on the dorsum skin, histopathological changes, spleen/body ratio, cytokines were investigated. In addition, the effects on proliferations of splenocytes were also investigated in vitro and vivo study. Results : LC spread(SPR) group and LC spread and administered(SPR+ADM) group showed diminished ear thicknesses. In SPR+ADM group, ear weights were lowered significantly compared to contact dermatitis control(CTL) group. LC treatment diminished erythema, desquamation and keratosis which were induced by repeated painting of DNCB. In histopathological observation, spongiosis and edema were diminished in SPR and SPR+ADM group. In cytokines, SPR+ADM group were increased in IL-10, and SPR and SPR+ADM group were decreased in TNF-${\alpha}$ compared with control group. Conclusions : These data suggest that LC can decrease symptoms of ACD, then LC is useful to treat patient with ACD.

Design of self-piercing rivet to joint in advanced high strength steel and aluminium alloy sheets (초고장력강과 알루미늄 합금의 접합을 위한 SPR 설계)

  • Kim, Dongbum;Qiu, Yuangen;Cho, Hae-Yong
    • Journal of Welding and Joining
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    • v.33 no.3
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    • pp.75-80
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    • 2015
  • Self-piercing riveting is an joining method of advanced high strength steels (AHSS) and other dissimilar materials. It has attracted considerable interest from the automotive industry. The SPR has become an interesting alternative joining technique for difficult to weld materials such as steels and aluminium alloys. In this paper, self-piercing rivet and anvil for SPR were designed for the joining conditions with AHSS and aluminium alloy. Various conditions of SPR were simulated for the design of rivets and anvils. The simulated results were in good agreement with experimental ones. As a result, over HV500 rivet is desirable to joint SPFC780 AHSS and aluminum alloy.

Surface Plasmon Resonance Multisensing Using Thickness Difference of Additional Layer (부가층의 두께 차이를 이용한 표면플라즈몬공명 멀티센싱)

  • Kim, Young-Gyu;Oh, Myung-Hwan;Lee, Seung-Ki
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.55 no.10
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    • pp.492-498
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    • 2006
  • A novel surface plasmon resonance(SPR) multisensing method, which does not require imaging apparatus such as CCD, has been proposed and implemented experimentally. The proposed method is based on the multichannel SPR and the separation of signals by use of additional layers whose thickness is controlled. SPR signals are influenced by the thickness of sensing layer as well as the optical condition of sensing surface. As the SPR signals from different ligands are usually positioned closely, the reflected light from sensing surface does not provide us with the clear differences of resonance signal depending on the kinds of ligands. It was found from our experiments that SPR signals from each ligand that is located on the additional layer with different thickness can be separated clearly enough to identify various signals from different ligands. Proposed method with theoretical design and simulation has been verified experimentally by using $SiO_2$ thin film layer as additional layer.

A Portable Surface Plasmon Resonance Biosensor for Rapid Detection of Salmonella typhimurium

  • Nguyen, Hoang Hiep;Yi, So Yeon;Woubit, Abdela;Kim, Moonil
    • Applied Science and Convergence Technology
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    • v.25 no.3
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    • pp.61-65
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    • 2016
  • Here, the rapid detection of Salmonella typhimurium by a portable surface plasmon resonance (SPR) biosensor in which the beam from a diode laser is modulated by a rotating mirror is reported. Using this system, immunoassay based on lipopolysaccharides (LPS)-specific monoclonal anti-Salmonella antibody was performed. For the purpose of orientation-controlled immobilization of antibodies on the SPR chip surface, the cysteine-mediated immobilization method, which is based on interaction between a gold surface and a thiol group (-SH) of cysteine, was adopted. As a result, using the portable SPR-based immunoassay, we detected S. typhimurium in the range from 10^7 CFU/mL to 10^9 CFU/mL within 1 hour. The results indicate that the portable SPR system could be potentially applied for general laboratory detection as well as on-site monitoring of foodborne, clinical, and environmental agents of interest.

A Study on the Vibration Reduction of the SPR(sudden pressure relay) in the Single Phase Main Power Transformers(345kV) (단상(345kV) 주변압기 압력 계전기의 진동절연에 관한 연구)

  • Park, Chul-Jun;Lee, Seong-Wook;Choi, Won-Ho;Lee, Wook-Ryun;Kweon, Ki-Young
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.20 no.5
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    • pp.486-491
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    • 2010
  • In this paper, it is identified that high-level vibration of the single phase main power transformers shut down due to the mechanical fault. vibration sources of the SPR in the transformer's are identified and the SPR vibrations are reduced by structural modification. For vibration characteristic identification, vibration signals were measured with an accelerometer when the transformer is driving. These signals are presented in a FFT analysis in order to find the dependency of frequency components on the transformer. From finite element analyses and some experiments, it is also found that resonances occur because the natural frequencies of the SPR exist in usual driving range. To shift the natural frequencies outside the driving range, the SPR is modified by increasing stiffness. It is verified that considerable amounts of vibration are reduced by the structural modification.

Graphene Coated Optical Fiber SPR Biosensor

  • Kim, Jang Ah;Hwang, Taehyun;Dugasani, Sreekantha Reddy;Kulkarni, Atul;Park, Sung Ha;Kim, Taesung
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.401-401
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    • 2014
  • In this study, graphene, the most attractive material today, has been applied to the wavelength-modulated surface plasmon resonance (SPR) sensor. The optical fiber sensor technology is the most fascinating topic because of its several benefits. In addition to this, the SPR phenomenon enables the detection of biomaterials to be label-free, highly sensitive, and accurate. Therefore, the optical fiber SPR sensor has powerful advantages to detect biomaterials. Meanwhile, Graphene shows superior mechanical, electrical, and optical characteristics, so that it has tremendous potential to be applied to any applications. Especially, grapheme has tighter confinement plasmon and relatively long propagation distances, so that it can enhance the light-matter interactions (F. H. L. Koppens, et al., Nano Lett., 2011). Accordingly, we coated graphene on the optical fiber probe which we fabricated to compose the wavelength-modulated SPR sensor (Figure 1.). The graphene film was synthesized via thermal chemical vapor deposition (CVD) process. Synthesized graphene was transferred on the core exposed region of fiber optic by lift-off method. Detected analytes were biotinylated double cross-over DNA structure (DXB) and Streptavidin (SA) as the ligand-receptor binding model. The preliminary results showed the SPR signal shifts for the DXB and SA binding rather than the concentration change.

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