• 제목/요약/키워드: fluorescence imaging

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A Coumarin-based Fluorescent Sensor for Selective Detection of Copper (II)

  • Wang, Jian-Hong;Guo, Xin-Ling;Hou, Xu-Feng;Zhao, Hui-Jun;Luo, Zhao-Yang;Zhao, Jin
    • Bulletin of the Korean Chemical Society
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    • 제35권8호
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    • pp.2400-2402
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    • 2014
  • Cu (II) detection is of great importance owing to its significant function in various biological processes. In this report, we developed a novel coumarin-based chemosensor bearing the salicylaldimine unit (2) for $Cu^{2+}$ selective detection. The results from fluorescence spectra demonstrated that the sensor could selectively recognize $Cu^{2+}$ over other metal cations and the detection limit is as low as $0.2{\mu}M$. Moreover, the confocal fluorescence imaging in HepG2 cells illustrated its potential for biological applications.

Single-molecule fluorescence in situ hybridization: Quantitative imaging of single RNA molecules

  • Kwon, Sunjong
    • BMB Reports
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    • 제46권2호
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    • pp.65-72
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    • 2013
  • In situ detection of RNAs is becoming increasingly important for analysis of gene expression within and between intact cells in tissues. International genomics efforts are now cataloging patterns of RNA transcription that play roles in cell function, differentiation, and disease formation, and they are demon-strating the importance of coding and noncoding RNA transcripts in these processes. However, these techniques typically provide ensemble averages of transcription across many cells. In situ hybridization-based analysis methods complement these studies by providing information about how expression levels change between cells within normal and diseased tissues, and they provide information about the localization of transcripts within cells, which is important in understanding mechanisms of gene regulation. Multi-color, single-molecule fluorescence in situ hybridization (smFISH) is particularly useful since it enables analysis of several different transcripts simultaneously. Combining smFISH with immunofluorescent protein detection provides additional information about the association between transcription level, cellular localization, and protein expression in individual cells.

Different modes of antibiotic action of homodimeric and monomeric bactenecin, a cathelicidin-derived antibacterial peptide

  • Lee, Ju-Yeon;Yang, Sung-Tae;Kim, Hyo-Jeong;Lee, Seung-Kyu;Jung, Hyun-Ho;Shin, Song-Yub;Kim, Jae-Il
    • BMB Reports
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    • 제42권9호
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    • pp.586-592
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    • 2009
  • The bactenecin is an antibacterial peptide with an intramolecular disulfide bond. We recently found that homodimeric bactenecin exhibits more potent antibacterial activity than the monomeric form and retains its activity at physiological conditions. Here we assess the difference in the modes of antibiotic action of homodimeric and monomeric bactenecins. Both monomeric and dimeric bactenecins almost completely killed both Staphylococcus aureus and E. coli within 10-30 min at concentrations of $8-16\;{\mu}M$. However, exposure to liposomes elicited an increase in the fluorescence quantum yield from a tryptophan-containing monomeric analog, while the homodimeric analog showed a significant reduction in fluorescence intensity. Moreover, unlike the monomer, the homodimer displayed apparent membrane-lytic activity enabling release of various sized dyes from liposomes, and rapidly and fully depolarized the S. aureus membrane. Together, our results suggest that homodimeric bactenecin forms pores in the bacterial membrane, while monomeric one penetrates through the membrane to target intracellular molecules/organelles.

Detection of the fluorescent emission of hydrogen in the Taurus cloud

  • Dae-Hui Lee;In-Su Yuk;Jang-Hyeon Park;Ho Jin;Gwang-Il Seon;Uk-Won Nam;Won-Yong Han;Gyeong-Uk Min;Gwang-Seon Yu
    • 한국우주과학회:학술대회논문집(한국우주과학회보)
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    • 한국우주과학회 2004년도 한국우주과학회보 제13권1호
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    • pp.99-99
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    • 2004
  • We detected and analyzed molecular hydrogen fluorescence in the Taurus Cloud using the Far-ultraviolet Imaging Spectrograph (FIMS) on the STSAT-1 which was launched at SeP. 27 2003. FIMS is optimized for observing diffuse emission lines in the interstellar medium in the wavelength bands of 900-l150 and 1300-1700 angstrom. The Taurus region is a local molecular cloud which is good for studying molecular hydrogen fluorescence emissions. (omitted)

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Design and Fabrication of a Multi-modal Confocal Endo-Microscope for Biomedical Imaging

  • Kim, Young-Duk;Ahn, Myoung-Ki;Gweon, Dae-Gab
    • Journal of the Optical Society of Korea
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    • 제15권3호
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    • pp.300-304
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    • 2011
  • Optical microscopes are widely used for medical imaging these days, but biopsy is a lengthy process that causes many problems during the ex-vivo imaging procedure. The endo-microscope has been studied to increase accessibility to the human body and to get in-vivo images to use for medical diagnosis. This research proposes a multi-modal confocal endo-microscope for bio-medical imaging. We introduce the design process for a small endoscopic probe and a coupling mechanism for the probe to make the multi-modal confocal endo-microscope. The endoscopic probe was designed to decrease chromatic and spherical aberrations, which deteriorate the images obtained with the conventional GRIN lens. Fluorescence and reflectance images of various samples were obtained with the proposed endo-microscope. We evaluated the performance of the proposed endo-microscope by analyzing the acquired images, and demonstrate the possibilities of in-vivo medical imaging for early diagnosis.

융합 바이오 이미징을 위한 염료 도핑 된 실리카 나노입자의 형광 특성에 관한 연구 (A Study on the Fluorescence Characteristics of Dye-doped Silica Nanoparticles for Integrated Bio Imaging)

  • 김기출
    • 융합정보논문지
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    • 제8권5호
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    • pp.45-50
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    • 2018
  • 형광 염료가 도핑 된 실리카 나노입자는 DNA 마이크로 에레이와 같은 바이오 라벨링 및 바이오 이미징에 활용되고 있으며, 높은 생체 적합성과 낮은 독성 및 높은 친수성의 특성을 가지고 있어 많은 주목을 받고 있는 기능성 나노소재이다. 본 논문에서는 형광 유기염료를 에탄올과 탈이온수에 각각 용해시킨 후 형광염료를 실리카 나노입자에 물리적으로 흡착시키는 방법과 화학적으로 도핑 시키는 방법으로 실리카 나노입자를 합성한 후 365 nm 파장의 자외선을 조사하여 형광특성을 분석하였다. 연구결과 형광 염료를 물리적으로 흡착시킨 실리카 나노입자보다 화학적으로 형광 염료를 도핑 시킨 실리카 나노입자의 형광특성이 우수하였으며, 도핑 된 형광 염료의 양이 많을수록 형광특성이 우수하였다. 형광 염료를 용해시키는 용매의 경우, 에탄올이 탈이온수와 비교하여 탁월한 형광 특성을 나타내었다. 또한 순수한 형광 염료와 형광 염료가 도핑된 실리카 나노입자의 광안정성을 조사한 결과, 형광 염료가 도핑 된 실리카 나노입자의 광안정성이 보다 우수한 것으로 나타났다. 이러한 연구결과를 바탕으로 형광염료가 최적으로 도핑 된 실리카 나노입자를 바이오 이미징 에이전트로 사용한다면 높은 광안정성과 형광특성으로 인하여 인체 내부의 생체 모니터링에 유용하게 활용될 것으로 전망된다.

Extraosseous Ewing's Sarcoma Presented as a Rectal Subepithelial Tumor: Radiological and Pathological Features

  • Bae, Heejin;Chung, Taek;Park, Mi-Suk;Kim, Myeong-Jin;Lim, Joon Seok;Kim, Honsoul
    • Investigative Magnetic Resonance Imaging
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    • 제21권1호
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    • pp.51-55
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    • 2017
  • Purpose: Extraosseous Ewing's sarcoma (EOE) of the rectum is extremely rare: only three cases have been reported in the literature and none of these reports described their imaging findings in detail. Herein, we describe the tumor imaging and pathological features in detail. Materials and Methods: We report a case of rectal EOE in a 72-year-old female who received local excision and was provisionally diagnosed with a rectal submucosal spindle cell tumor. We used immunohistochemistry, histopathology, and fluorescence in situ hybridization to characterize the tumor and provide a definitive diagnosis of EOE. Results: MRI revealed a well-demarcated submucosal tumor with heterogeneous enhancement and hemorrhagic foci in rectum. EOE was diagnosed by positive staining of tumor cells for CD99 and Fli-1 by immunohistochemistry and the presence of the EWSR1 gene translocation by fluorescence in situ hybridization. Although the patient underwent radiation treatment and surgery, the tumor recurred after 4 months as revealed by computed tomography and magnetic resonance imaging. Conclusion: Rectal EOE may present as a rectal submucosal tumor. The understanding of imaging and histological characteristics of this tumor are critical for accurate diagnosis and appropriate aggressive treatment.