• 제목/요약/키워드: Gold particles

검색결과 183건 처리시간 0.041초

Transgenic Plants of Easter Lily (Lilium longiflorum) with Phosphinothricin Resistance

  • Ahn, Byung Joon;Joung, Young Hee;Kamo, Kathryn K.
    • Journal of Plant Biotechnology
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    • 제6권1호
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    • pp.9-13
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    • 2004
  • Transient uidA expression was used to optimize parameters required for biolistic transformation of suspension cells of Easter lily, Lilium longiflourm. Maximum uidA expression occurred following bombardment with gold particles as compared to tungsten. A 3hr pre-treatment of suspension cells with 0.125M osmoticum resulted in a 1.5X increase in uidA expression. A helium pressure of 1550 psi combined with a particle travelling distance of 6cm resulted in maximum uidA expression as compared to either 1100, 1200, or 1800 psi. Transient transformation resulted in up to 493 uidA expressing cells/Petri plate. For stable transformation suspension cells of Lilium longiflorum, were co-bombarded with plasmid DNA containing cucumber mosaic virus (CMV) replicase under the rice actin (Act1) promoter and either the bar or PAT genes under the cauliflower mosaic virus (CaMV 355) promoter. Ten regenerated plants contained the transgene as analyzed by PCR, and two of the ten plants were confirmed to contain the transgene by Southern hybridization. The two transgenic plants were independent transformants, one containing the bar gene and the other both the CMV replicase and bar genes. Plants were sprayed at the rosette stage and found to be resistant to 1000 mg/L of phosphinothricin (Trade name-Ignite) indicating expression of the bar gene throughout the leaves when bar was under control of the CaMV 35S promoter.

Glucose Oxidation on Gold-modified Copper Electrode

  • Lim, Ji-Eun;Ahn, Sang Hyun;Pyo, Sung Gyu;Son, Hyungbin;Jang, Jong Hyun;Kim, Soo-Kil
    • Bulletin of the Korean Chemical Society
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    • 제34권9호
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    • pp.2685-2690
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    • 2013
  • The activities of Au-modified Cu electrodes toward glucose oxidation are evaluated according to their fabrication conditions and physico-chemical properties. The Au-modified Cu electrodes are fabricated by the galvanic displacement of Au on a Cu substrate and the characteristics of the Au particles are controlled by adjusting the displacement time. From the glucose oxidation tests, it is found that the Au modified Cu has superior activity to the pure Au or Cu film, which is evidenced by the negative shift in the oxidation potential and enhanced current density during the electrochemical oxidation. Though the activity of the Au nanoparticles is a contributing factor, the enhanced activity of the Au-modified Cu electrode is due to the increased oxidation number of Cu through the electron transfer from Cu to more electronegative Au. The depletion of electron in Cu facilitates the oxidation of glucose. The stability of the Au-modified Cu electrode was also studied by chronoamperometry.

Nanoplasmonics: Enabling Platform for Integrated Photonics and Sensing

  • Yeo, Jong-Souk
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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    • pp.75-75
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    • 2015
  • Strong interactions between electromagnetic radiation and electrons at metallic interfaces or in metallic nanostructures lead to resonant oscillations called surface plasmon resonance with fascinating properties: light confinement in subwavelength dimensions and enhancement of optical near fields, just to name a few [1,2]. By utilizing the properties enabled by geometry dependent localization of surface plasmons, metal photonics or plasmonics offers a promise of enabling novel photonic components and systems for integrated photonics or sensing applications [3-5]. The versatility of the nanoplasmonic platform is described in this talk on three folds: our findings on an enhanced ultracompact photodetector based on nanoridge plasmonics for photonic integrated circuit applications [3], a colorimetric sensing of miRNA based on a nanoplasmonic core-satellite assembly for label-free and on-chip sensing applications [4], and a controlled fabrication of plasmonic nanostructures on a flexible substrate based on a transfer printing process for ultra-sensitive and noise free flexible bio-sensing applications [5]. For integrated photonics, nanoplasmonics offers interesting opportunities providing the material and dimensional compatibility with ultra-small silicon electronics and the integrative functionality using hybrid photonic and electronic nanostructures. For sensing applications, remarkable changes in scattering colors stemming from a plasmonic coupling effect of gold nanoplasmonic particles have been utilized to demonstrate a detection of microRNAs at the femtomolar level with selectivity. As top-down or bottom-up fabrication of such nanoscale structures is limited to more conventional substrates, we have approached the controlled fabrication of highly ordered nanostructures using a transfer printing of pre-functionalized nanodisks on flexible substrates for more enabling applications of nanoplasmonics.

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Immunoelectron microscopic localization of partially purified antigens in adult Paragonimus iloktsuenensis

  • Lee, Ok-Ran;Chung, Pyung-Rim
    • Parasites, Hosts and Diseases
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    • 제39권2호
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    • pp.119-132
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    • 2001
  • An immunoelectron microscopy employing immunogold labeling method was performed to detect tissue origin of Dl fraction (DIA) among 5 antigenic protein fractions partially purified by DEAE- anion exchange chromatography from water- soluble crude antigen (PIWA) of adult Paragonimus iloktsuenensis. Immune reactions of adult worm tissues with rabbit serum immunoglobulin immunized with crude antigen (PI-Ig) and D1 antigen (D1-Ig), as well as rat serum immunoglobulin infected with P. iloktsuenensis were observed. DlA showed strong antigenicity in the intestinal epithelium of the worms during the early infection period of 2-4 weeks after infection. The vitellaria also showed stronger antigenicity than the other tissue sites in immune reaction of tissues against all immunoglobulins from 4 to 33 weeks after vitelline development. Therefore, it is suggested that DlA was mainly originated from the intestinal epithelial tissues before the development of vitelline gland of the parasites. Immune-reactivity of two immunoglobulins (PI-Ig, Dl-Ig) was significantly different in intestinal epithelial cytoplasmic protrusions (CP) and intestinal epithelial secretory granules (SG). In the experimental group with Dl-Ig, gold particles were labeled significantly in CP than in SG when compared to the PI-Ig group. Thus, the major antigenic materials in Dl antigen having a strong antigenicity in the early infection period was considered to be originated from the intestinal epithelial tissue .

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SPM 용 카본 나노튜브 팁 조립의 실험적 연구 (Experimental study of assembly of the carbon nanotube tip for SPM)

  • 박준기;김지은;한창수;박영근;황규호
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2005년도 춘계학술대회 논문집
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    • pp.1228-1231
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    • 2005
  • This paper reports about the development of scanning probe microscopy (SPM) tip with multi-walled carbon nanotube (MWNT). For making a carbon nanotube (CNT) modified tips, AC electric field which causes the dielectrophoresis was used for alignment and deposition of CNTs to the metal coated SPM tip. By dropping the MWNT solution and applying an electric field between an SPM tip and an electrode, MWNTs which were dispersed into a diluted solution were directly assembled onto the apex of the SPM tips due to the attraction by the dielectrophoretic force. In this paper, we investigate experimental conditions about the alignment of the CNT to tip axis according to the change of the angle between a tip and an electrode. Experimental results are presented, and then fabricated CNT tips are showed and measurement results for 15nm gold particles are compared with that of the conventional silicon tip.

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나노물질의 세포독성 평가법으로 Colony Forming Efficiency Assay에 대한 검증연구 (Pre-validation of Colony Forming Efficiency Assay for Assessing the Cytotoxicity of Nanomaterials)

  • 조은혜;이재우;박선영;김필제;최경희;엄익춘
    • 한국환경보건학회지
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    • 제41권1호
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    • pp.17-23
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    • 2015
  • Objectives: The cytotoxcities of Au, Ag, SWCNT, $SiO_2$, and ZnO nanomaterials were evaluated in order to assess their potential toxicological effects in in vitro cell models using colony forming efficiency (CFE) assay. Methods: The CFE assay of the test materials was carried out on Hep G2 cells. The size distribution of nanomaterials was studied by transmission electron microscopy (TEM). Changes in cell viability after treatment with a toxicant will result in a decreased number of colonies formed in comparison to solvent. Results: The TEM images show that all the particles except SWCNT and ZnO can be considered approximately spherical. The gold and $SiO_2$ nanoparticles show no response (no toxicity) in concentration response experiments. A statistically significant toxic effect was found in Hep G2 cells treated with Ag, SWCNT and ZnO nanomaterials. Conclusion: In this study, we considered CFE assay to be a promising test for screening studies for cytotoxicity with physicochemical analysis.

탄탈륨 도핑 및 나노사이즈의 금입자분산된 $TiO_2$ 박막에서의 광전극 특성 비교 (Comparison of Photoelectrode Properties Between $TiO_2$ Thin films Doped with Tantalum and Dispersed with Nanosize Gold)

  • 윤종원;정경한;;권영수
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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    • pp.861-864
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    • 2004
  • 본 연구에서는 Ta이 도핑된 $TiO_2$$Au/TiO_2$ nanocomposite 박막을 co-sputtering법으로 제작하였다. Ta-doped $TiO_2$ 박막은 금흥석(rutile)에서 아나타제 상으로 변하는 구조를 유도하는 고용체를 형성했다. $Au/TiO_2$ nanocomposite film의 경우에는, 지름이 약 15 nm인 Au particles들이 $TiO_2$ matrix에 균질하게 분포되었다. Ta가 도핑된 $TiO_2$ 전극과 $Au/TiO_2$ 나노 콤포사이트 전극의 anodic photocurrents가 UV뿐만 아니라 가시광선 영역에서도 관찰되었다. Ta이 도핑된 $TiO_2$ 전극과 $Au/TiO_2$ 나노 콤포사이트 사이의 가시광선 영역에서 photoresponse는 계면 상태로 부터의 bandgap의 감소와 전자의 photoexcitation 때문이다.

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한국재래산양 뇌하수체의 성장자극세포와 젖샘자극세포에 관한 전자현미경적 연구 (Immunohistochemical electron microscopic studies on somatotropes and mammotropes in hypophysis of Korean native goat)

  • 이인세;이흥식;원무호;서제훈;송승훈;남영삼;강태천
    • 대한수의학회지
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    • 제38권3호
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    • pp.488-496
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    • 1998
  • Somatotropes, mammotropes and somatomammotropes of the Korean native goat hypophysis were studied by double immunoelectron microscopy using antisera to growth hormone(GH) and prolactin(PRL), and protein A-gold particles of different sizes. Mammotropes were round or oval in shape, and contained round and electron dense secretory granules. The size of secretory granules was variable from 460nm to 680nm in diameter. Somatotropes were elliptical or triangular in shape and the oval nucei were located eccentrically at the periphery of the cell. Secretory granules of the cell were oval in shape and clearly distinguished from round granules of mammotropes. The size of granules was 320~680nm in diameter, smaller than that of mammotropes. Somatomammotropes contained round or oval secretory granules. The granules had intermediate size between somatotropes and mammotropes. Some of granules contained both GH and PRL, while the others contained only one of them.

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진동막분리장치에 의한 반도체폐수처리와 재이용에 관한 연구 (A Study on the Semiconductor Wastewater Treatment and Recycling by VSEP system)

  • 강경환
    • 한국환경과학회지
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    • 제14권3호
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    • pp.335-343
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    • 2005
  • The objective of this research is to evaluate a feasibility of wastewater reuse by membrane treatment with vibrating membrane separation equipment. Molecular weight of compounds in wastewater, permeability of membrane and retentate characterization after membrane filtration were investigated in order to determine appropriate membrane pore size and materials for wastewater treatment. Selected membrane was evaluated with vibration membrane separation equipment to optimize operating conditions. The following conclusion are drawn. 1. We got as following test results after the distribution of particles in the semiconductor wastewater, are made up of $1\~20{\mu}m$. Si, gold and Al in turn are contained in semiconductor wastewater. 2. Recovery rate is changeless under increasing recovery rate in operation. Though a value can be if pressure can be changed, the highest value of permeate rate is presented in 150 psi. 3. The AS-100(polysulpone) was selected as the most appropriate membranes for the treatment of semi-conductor wastewater to VSEP system. The fouling almost did not occur during this experiments. The analyses of treated water with VSEP system showed conductivity: 0.059,us/cm, TDS: 40mg/l, COD: 20mg/l, SS : 5mg/l, n-Hexane: 8.3mg/l. Comparing previous systems, operating expenses is decreased by more $50\%$.

면역크로마토그래피법을 이용한 B형간염 진단용 kit의 개발 (Development of Diagnostic kit for Hepatitis B Susrface Antigen using Immunochromatographic Assay Method)

  • 신형순;신광순;정홍근;허태련
    • KSBB Journal
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    • 제15권2호
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    • pp.214-218
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    • 2000
  • 면역크로마토그래피 진단방법을 이용하는 B형간염 스크리닝 kit를 개발하기 위하여 두가지의 항체를 이용하였다. 표식자항체로 사용된 것은 단세포군항체 anti-HBs이고 포획항체는 goat anti-HBs 인데 포획항체는 니트로셀룰로즈 막에 고정되고 표식자항체는 금 입자에 결합된다. 혈청 검체를 well에 가하면 유리섬유 표면에 건조상태로 침착되어 있던 conjugate가 활성화되어 검체중의 HBsAg와 결합한다. 검체를 가한 지 5분 후 검사결과가 나타나는데 HBsAg와 conjugate가 결합된 복합체가 니트로셀롤로즈 막의 하단부에 붉은 색 선으로 나타난다. 본 kit의 검출한계는 표준 HBs-Ag 용액을 사용하여 시험하였을 때 2 ng/ml이었다.

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