• 제목/요약/키워드: Chemical Species

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Noble Metal Nanowire Based SERS Sensor

  • 강태준
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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    • pp.87-87
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    • 2013
  • The interface between nanomaterials and biosystems is emerging as one of the broadest and most dynamic areas of science and technology, bringing together biology, chemistry, physics and many areas of engineering, biomedicine. The combination of these diverse areas of research promised to yield revolutionary advances in healthcare, medicine, and life science. For example, the creation of new and powerful nanosensors that enable direct, sensitive, and rapid analysis of biological and chemical species can advance the diagnosis and treatment of disease, discovery and screening of new drug molecules. Nanowire based sensors are emerging as a powerful and general platform for ultrasensitive and multiplex detection of biological and chemical species. Here, we present the studies about noble metal nanowire sensors that can be used for sensitive detection of a wide-range of biological and chemical species including nucleic acids, proteins, and toxic metal ions. Moreover, the optical and electrochemical applications of noble metal nanowires are introduced. Noble metal nanowires are successfully used as plasmonic antennas and nanoelectrodes, thereby provide a pathway for a single molecule sensor, in vivo neural recording, and molecular injection and detection in a single living cell.

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An Investigation on Inorganic Arsenic in Seaweed by Ion Chromatography Combined with Inductively Coupled Plasma-Atomic Emission Spectrometry

  • Cui, Sheng;Na, Jin-Su;Kim, Na-Young;Lee, Yonghoon;Nam, Sang-Ho
    • Bulletin of the Korean Chemical Society
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    • 제34권11호
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    • pp.3206-3210
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    • 2013
  • This study focused on the matrix interference for the qualitative and quantitative analysis of inorganic arsenic species in seaweed by ion chromatography (IC) combined with inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The matrix of seaweed has a significant effect on the determination of inorganic arsenic species. In particular, the retention times of inorganic arsenic species in the in the standard solution were different from those in seaweed because of the matrix interference. Thus, it was not suitable to use the chromatographic method for the determination of the arsenic species in seaweed. We investigated an alternative method for the determination of inorganic arsenic species in seaweed. The method was applied for the seaweed samples such as laver, green laver, sea tangle and sea mustard. The sample extraction methods of the arsenic species were also investigated in this study.

Differentiation of Roots of Glycyrrhiza Species by 1H Nuclear Magnetic Resonance Spectroscopy and Multivariate Statistical Analysis

  • Yang, Seung-Ok;Hyun, Sun-Hee;Kim, So-Hyun;Kim, Hee-Su;Lee, Jae-Hwi;Whang, Wan-Kyun;Lee, Min-Won;Choi, Hyung-Kyoon
    • Bulletin of the Korean Chemical Society
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    • 제31권4호
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    • pp.825-828
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    • 2010
  • To classify Glycyrrhiza species, samples of different species were analyzed by $^1H$ NMR-based metabolomics technique. Partial least squares discriminant analysis (PLS-DA) was used as the multivariate statistical analysis of the 1H NMR data sets. There was a clear separation between various Glycyrrhiza species in the PLS-DA derived score plots. The PLS-DA model was validated, and the key metabolites contributing to the separation in the score plots of various Glycyrrhiza species were lactic acid, alanine, arginine, proline, malic acid, asparagine, choline, glycine, glucose, sucrose, 4-hydroxy-phenylacetic acid, and formic acid. The compounds present at relatively high levels were glucose, and 4-hydroxyphenylacetic acid in G. glabra; lactic acid, alanine, and proline in G. inflata; and arginine, malic acid, and sucrose in G. uralensis. This is the first study to perform the global metabolomic profiling and differentiation of Glycyrrhiza species using $^1H$ NMR and multivariate statistical analysis.

EPR Study of${\gamma}(1,2)-[H{_n}SiV^{IV}VW_{10}O_{40}]^{(7-n)-}$ (n = 0, 1 or 2). Identification of Four One-Electron Reduction Products and Evidence for Proton Transfer in the Solid State

  • Jeongmin Park;Hyunsoo So
    • Bulletin of the Korean Chemical Society
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    • 제15권9호
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    • pp.752-758
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    • 1994
  • Several one-electron reduction products of ${\gamma}$(1,2)-[$H_nSiV_2W_{10}O_{40}]^{(6-n)-}$ were separated by precipitating or coprecipitating with diamagnetic host compounds at different pH. Mono-and diprotonated species, 1 and 2, in powder samples exhibit aPR spectra characteristic of a mononuclear oxovanadium species, indicating that the unpaired electron is trapped at one vanadium atom. The EPR spectrum of the unprotonated species 0 shows 15 parallel lines, indicating that the unpaired electron interacts equally with two vanadium atoms. While different species were precipitated depending upon the pH of the solution and the charge of the host anion, only one species 1' was formed in the frozen solutions at pH 3.2-4.7. The EPR spectrum of 1' indicates that the unpaired electron is trapped at one vanadium atom and 1/16 of the spin density is delocalized onto the second vanadium atom. The species 1' is probably another form of the monoprotonated species. The EPR spectra show that some of 2 transform into 1 and some of 0 transform into 1' in the solid state at low temperatures. It is suggested that proton transfer between the heteropolyanion and water molecues in the solid state is involved in these transformations.

Chemical Composition, Degradation Characteristics and Effect of Tannin on Digestibility of Some Browse Species from Kenya Harvested during the Wet Season

  • Osuga, I.M.;Abdulrazak, S.A.;Ichinohe, T.;Fujihara, T.
    • Asian-Australasian Journal of Animal Sciences
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    • 제18권1호
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    • pp.54-60
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    • 2005
  • A study was conducted with the objective of evaluating the nutritive value of some browse species from Kenya. The species evaluated included: Bauhinia alba, Bauhinia variegata, Bridelia micrantha, Calliandra calothyrsus, Carisa edulis, Cratylia argentea, Gliricidia sepium, Lantana camara, Maerua angolensis, Sesbania micrantha and S. sesban. The browses were evaluated by their chemical composition including phenolics, in vitro gas production and tannin activity (tannin bioassay). All the species had high crude protein content (149-268 g/kg DM) and low NDF content (239-549 g/kg DM). The feeds had varying contents of total extractable tannins (TET) ranging from low (3-22 mg/g DM), moderate (42-58 mg/g DM) and high (77-152 mg/g DM). Calliandra calothyrsus had the highest tannin content. Significant (p<0.05) variation in gas production was recorded among the species. Sesbania micrantha had the highest (p<0.05) potential gas production while Gliricidia sepium had the highest (p<0.05) rate of gas production. Use of polyethylene glycol (PEG 6000), to assess the adverse affect of tannins, indicated that tannins in browse species with high tannin content had inhibitory effects on rumen microbial fermentation as indicated by the gas production. Estimated organic matter digestibility and metabolizable energy also increased with PEG addition. The results of this study indicate that such Kenyan browse species have the potential to be used as feed supplements for ruminant animals.

Anatomical Proportions and Chemical and Amino Acid Composition of Common Shrimp Species in Central Vietnam

  • Ngoan, L.D.;Lindberg, J.E.;Ogle, B.;Thomke, S.
    • Asian-Australasian Journal of Animal Sciences
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    • 제13권10호
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    • pp.1422-1428
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    • 2000
  • This investigation was conducted to evaluate the shrimp flesh (SF) and shrimp by-product (SB) of the most abundant shrimp species (Metapenaeus affinis, Penaeus semisulcatus and Penaeus monodon) caught in Central Vietnam, with the emphasis on yield, gross and amino acid (AA) composition and effect of heat treatment. The results showed that the mean edible SF and SB (head and shells with tail) yields of the three shrimp species averaged 56.7 and 43.3%, respectively, of the total wet body weight, with the M. affinis generating the highest by-product yield (45.7%) and P. semisulcatus (40.6%) the lowest. Significant differences in dry matter (DM), crude protein (CP) and ash content were found between SF and SB. The DM content of SF (21.5%) was lower than of SB (24.9%) and the ash content (on a DM basis) of the SB in all shrimp species was more than three times that of the SF (p<0.05), whereas the CP content was almost twice as high in the SF as compared with the SB (p<0.05). The SB of the three species contained (on a DM basis) between 44.0 and 49.8% CP (p<0.05) and between 13.5 and 18.1% chitin (p<0.05). The Ca content of SB differed also between species (p<0.05). On average, the sum of AA in SB corresponded to 89.3% of the CP and essential AA accounted for about 50% of the total AA. The most abundant AA were arginine, aspartic and glutamic acids, which accounted for 33% of the total AA. Minor, but significant differences in some AA concentrations of SB between species were observed (p<0.05). With the exception of the DM and ether extract content, all other chemical constituents of entire shrimp, SF and SB were not significantly affected by heat treatment (p>0.05).