• Title/Summary/Keyword: Biological engineering

검색결과 9,398건 처리시간 0.036초

Detection of ${\alpha}-Cyclodextrin$ and E.coli Cell Using Polydiacetylene Supramolecules

  • Lee, Gil-Sun;Choi, Hyun;Lee, Chung-Wan;Ahn, Dong-June;Oh, Min-Kyu;Kim, Jong-Man
    • 한국고분자학회:학술대회논문집
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    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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    • pp.306-306
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    • 2006
  • We immobilized and patterned PDA vesicles on solid substrate using micro arrayer, which have moieties to react with chemical and biological materials. Immobilized vesicle system was developed since it possesses many advantages in multiple screening, durable stability, and higher sensitivity. We applied polydiacetylene supramolecules to chemical and biological sensors for detection of ${\alpha}-cyclodextrin$ and E.coli cell selectively. This detection method could be applied as DNA chip, protein chip, and cell chip for multiple screening as well as chemical sensor by modifying the functional groups of diacetylene monomer.

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Characterization of Rajath Bhasma and Evaluation of Its Toxicity in Zebrafish Embryos and Its Antimicrobial Activity

  • Kalimuthu, Kalishwaralal;Kim, Ji Min;Subburaman, Chandramohan;Kwon, Woo Young;Hwang, Sung Hyun;Jeong, Sehan;Jo, Min Geun;Kim, Hyung Joo;Park, Ki Soo
    • Journal of Microbiology and Biotechnology
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    • 제30권6호
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    • pp.920-925
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    • 2020
  • In India, nanotechnology has been used in therapeutic applications for several millennia. One example of a traditional nanomedicine is Rajath Bhasma (also called calcined silver ash), which is used as an antimicrobial and for the treatment of various ailments and conditions such as memory loss, eye diseases, and dehydration. In this study, we aimed to characterize the physical composition and morphology of Rajath Bhasma and its suitability for use as a non-toxic antimicrobial agent. First, Rajath Bhasma was physically characterized via i) Fourier-transform infrared spectroscopy to analyze the surface functional groups, ii) scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy to observe the morphology and elemental composition, and iii) X-ray diffraction to determine the crystalline phases. Thereafter, functional characterization was performed through toxicity screening using zebrafish embryos and through antimicrobial activity assessment against gram-positive (Staphylococcus epidermidis) and gram-negative (Escherichia coli) bacteria. Rajath Bhasma was found to harbor alkene, hydroxyl, aldehyde, and amide functional groups originating from biological components on its surface. The main component of Rajath Bhasma is silver, with particle size of 170-210 nm, and existing in the form of spherical aggregates with pure crystalline silver structures. Furthermore, Rajath Bhasma did not exert toxic effects on zebrafish embryos at concentrations below 5 ㎍/ml and exhibited effective antimicrobial activity against both gram-positive and gram-negative bacteria. The present results indicate that Rajath Bhasma is a potentially effective antimicrobial agent without toxicity when used at concentrations below 5 ㎍/ml.

Synthesis and Properties of Ionic Liquids:Imidazolium Tetrafluoroborates with Unsaturated Side Chains

  • Min, Gwan-Hong;Yim, Tae-eun;Lee, Hyun-Yeong;Huh, Dal-Ho;Lee, Eun-joo;Mun, Jun-young;Oh, Seung M.;Kim, Young-Gyu
    • Bulletin of the Korean Chemical Society
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    • 제27권6호
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    • pp.847-852
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    • 2006
  • Imidazolium tetrafluoroborate ionic liquids having unsaturated aliphatic side chains were synthesized and characterized. Most of them are liquid at room temperature and all of them are stable up to $300{^{\circ}C}$. Some imidazolium tetrafluoroborates with an allylic side chain showed much wider voltage windows on the platinum electrode, better conductivities, and lower viscosities compared with the corresponding ionic liquids containing the saturated side chains.

Synthesis and Physicochemical Properties of Ionic Liquids: 1-Alkenyl-2,3-dimethylimidazolium Tetrafluoroborates

  • Min, Gwan-Hong;Yim, Tae-Eun;Lee, Hyun-Yeong;Kim, Hyo-Jin;Mun, Jun-Young;Kim, Sang-Mi;Oh, Seung-M.;Kim, Young-Gyu
    • Bulletin of the Korean Chemical Society
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    • 제28권9호
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    • pp.1562-1566
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    • 2007
  • 1-Alkenyl-2,3-dimethylimidazolium tetrafluoroborate ionic liquids having an olefinic substituent were synthesized and characterized. Among them, [AMMIm]BF4 with an allyl group showed lower viscosity, higher ionic conductivity, and a wider electrochemical window compared with its analogue having a saturated alkyl substituent. An EDLC with [AMMIm]BF4 showed better performance than that with [PMMIm]BF4, too.

A Study on the Quantitative Regularity Measures That Are Suitable for Biological Signal Analysis - Standard Data and 24 Hour R-R interval Analysis

  • 남영한;이종민;한주만;박광석
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1998년도 추계학술대회
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    • pp.197-198
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    • 1998
  • We tested the capability of Pointwise Correlation Dimension(PD2), Approximate Entropy (ApEn) and LZ complexity, as alternative measures of a biological signal. For this purpose, we analyzed standard data and a healthy child's 24-hour heart rate variability. Our conclusion is as follows. First, PD2, ApEn and LZ complexity can be used for discerning chaotic attractor, white noise, and periodic signal. Second, these measures show different characteristics on day and night. Third, these measures can be used for detecting time-varying characteristics of biological signals.

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