• Title/Summary/Keyword: Mass spectroscopy

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Antioxidant compound from the Lycopersicon esculentum (토마토(Lycopersicon esculentum)로부터 GSH 회복능을 보이는 항산화 화합물의 분리 동정)

  • Kim, Hyoung-Geun;Jeon, Hyeong-Ju
    • Journal of Applied Biological Chemistry
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    • v.63 no.4
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    • pp.319-325
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    • 2020
  • The liquids of Lycopersicon esculentum were extracted with 70% aqueous MeOH and the concentrates were partitioned into EtOAc, n-BuOH, and H2O fractions. The repeated silica gel and octadecyl silica gel column chromatographies for the EtOAc fraction, whose activity was confirmed, led to isolation of one flavonol compound. The chemical structures of the compound were determined as quercetin (1) based on spectroscopic analyses including nuclear magnetic resornance, infrarad spectroscopy, and mass spectroscopy. Through this study, the antioxidant efficacy was confirmed by demonstrating that the L. esculentum fraction showing an increase in glutathione mean (GM) and a decrease in glutathione heterogeneity (GH) uniformly raises the intracellular glutathione (GSH) level.

Resonantly-enhanced Two-photon Ionization and Mass-Analyzed Threshold Ionization (MATI) Spectroscopy of 2-Hydroxypyridine

  • Lee, Dae-Hyun;Baek, Sun-Jong;Choi, Kyo-Won;Choi, Young-S.;Kim, Sang-Kyu
    • Bulletin of the Korean Chemical Society
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    • v.23 no.2
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    • pp.277-280
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    • 2002
  • Mass-analyzed threshold ionization (MATI) spectra of 2-hydroxypyridines existing as lactims (2-pyridinol) in a molecular beam are obtained via (1+1') two-photon process to give accurate ionization energies of 8.9344${\pm}$0.0005 and 8.9284${\pm}$0.0005 eV for 2-pyridinol (2Py-OH) and its deuterated analogue (2Py-OD), respectively. Resonantly-enhanced two-photon ionization spectra of these compounds are also presented to give vibrational structures of their $S_1$ states. Vibrational frequencies of 2Py-OH and 2Py-OD in ionic ground states are accurately determined from MATI spectra taken via various $S_1$ intermediate states, and associated vibrational modes are assigned with the aid of ab initio calculations.

Distant Quasars: Black hole mass growth and dust emission

  • Jun, Hyunsung D.
    • The Bulletin of The Korean Astronomical Society
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    • v.40 no.1
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    • pp.43.2-43.2
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    • 2015
  • The massive limit of black holes (BHs) is observed as present day ten billion solar masses. We search for observational signatures of BHs that become extremely massive (EMBHs, 1-10 billion solar masses). I will report on the evolution of active galactic nuclei (AGNs) through the growth of BH mass and their dust emission strength. First, we measured 26 EMBH masses of quasars at 1

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Identification of Propentofylline Metabolites in Rats by Gas Chromatography/Mass Spectrometry

  • Kwon, Oh-Seung;Ryu, Jae-Chun
    • Archives of Pharmacal Research
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    • v.23 no.4
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    • pp.374-380
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    • 2000
  • Propentofylline (PPF, 3-methyl-1-(5-oxohexyl)-7-propylxanthine) has been reported to be a compound for treatment of both vascular dementia and dementia of the Alzheimer type. The short half-life (about 15 min) of PPF at the terminal elimination phase and poor bioavailability after oral administration of PPF to rabbits (Kim et al., 1992) suggest in part that this drug takes the extensive first-pass metabolism in the liver. In addition, the metabolic pathway for PPF remains unclear. The objective of this experiment is to identify urinary metabolites of PPF in rats. For the identification of the metabolites, rat urine was collected after oral administration of 100${m}g/kg$ PPF. PPF metabolite, 3-methyl-1-(5-hydroxyhexyl)-7-propylxanthine, was synthesized and confirmed by gas chromatography/mass spectroscopy (GC/MS) and $^1H$ nuclear magnetic resonance spectroscopy. The urinary metabolites of PPF were extracted with diethyl ether and identified by electron impact and chemical ionization GC/MS. One urinary metabolite was confirmed to be 3-methyl-1-(5-hydroxyhexyl)-7-propylxanthine by synthesized authentic compound. Several metabolites of monohydroxy- and dihydroxy-PPF were identified based on mass fragmentation of both intact and trimethylsilylated derivatives of PPF metabolites and the novel structure of these metabolites is suggested based on mass spectra.

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Calcium pyrophosphate dihydrate deposition disease in the temporomandibular joint: diagnosis and treatment

  • Kwon, Kwang-Jun;Seok, Hyun;Lee, Jang-Ha;Kim, Min-Keun;Kim, Seong-Gon;Park, Hyung-Ki;Choi, Hang-Moon
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.40
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    • pp.19.1-19.6
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    • 2018
  • Background: Calcium pyrophosphate dihydrate deposition disease (CPDD) is a rare disease in the temporomandibular joint (TMJ) space. It forms a calcified crystal mass and induces a limitation of joint movement. Case presentation: The calcified mass in our case was occupied in the left TMJ area and extended to the infratemporal and middle cranial fossa. For a complete excision of this mass, we performed a vertical ramus osteotomy and resected the mass around the mandibular condyle. The calcified mass in the infratemporal fossa was carefully excised, and the segmented mandible was anatomically repositioned. Scanning electronic microscopy (SEM)/energy-dispersive X-ray spectroscopy (EDS) microanalysis was performed to evaluate the calcified mass. The result of SEM/EDS showed that the crystal mass was completely composed of calcium pyrophosphate dihydrate. This result strongly suggested that the calcified mass was CPDD in the TMJ area. Conclusions: CPDD in the TMJ is a rare disease and is difficult to differentially diagnose from other neoplasms. A histological examination and quantitative microanalysis are required to confirm the diagnosis. In our patient, CPDD in the TMJ was successfully removed via the extracorporeal approach. SEM/EDS microanalysis was used for the differential diagnosis.

MR Spectroscopy and Diffusion Weighted Imaging Findings of Primary Non-Hodgkin Lymphoma of the Breast: Two Case Reports (유방에 발생한 일차성 비호지킨림프종의 자기공명 분광법 및 확산강조 영상: 2예)

  • Nam, Sang Yu;Yoo, Eun Young;Choi, Hye-Young
    • Investigative Magnetic Resonance Imaging
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    • v.18 no.2
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    • pp.176-181
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    • 2014
  • Primary non-Hodgkin lymphoma (NHL) of the breast is a very rare disease, and the mammographic and ultrasonographic findings of breast lymphoma are variable. There are several reports of magnetic resonance (MR) imaging findings in patients with breast lymphomas; however, few reports have described the findings observed on MR spectroscopy or the features of diffusion weighted (DW) imaging. The authors report the findings of classical MR imaging, MR spectroscopy and DW imaging of a 48-year-old woman and a 40-year-old woman with primary non-Hodgkin's lymphoma of breasts. Mammography and breast ultrasonography revealed a mass with circumscribed margin. The mass showed strong enhancement after contrast injection on MR imaging. DW imaging showed reduced diffusion and high-amplitude choline (Cho) peak at 3.22 ppm was detected by single voxel MR spectroscopy which was consistent with malignancy.

Haematococcus pluvialis Cell-Mass Sensing Using Ultraviolet Fluorescence Spectroscopy

  • Lababpour, Abdolmajid;Hong, Seong-Joo;Lee, Choul-Gyun
    • Journal of Microbiology and Biotechnology
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    • v.17 no.12
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    • pp.1922-1929
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    • 2007
  • A simple whole-cell-based sensing system is proposed for determining the cell mass of H. pluvialis using ultraviolet fluorescence spectroscopy. An emission signal at 368 nm was used to detect the various kinds of green, green-brown, brown-red, and red H. pluvialis cells. The fluorescence emission intensities of the cells were highest at 368 nm with an excitation wavelength of 227 nm. An excitation wavelength of 227 nm was then selected for cell-mass sensing, as the emission fluorescence intensities of the cell suspensions were highest at this wavelength after subtracting the background interference. The emission fluorescence intensities of HPLC-grade water, filtered water, and HPLC-grade water containing a modified Bold's basal medium (MBBM) were measured and the difference was less than 1.6 for the selected wavelengths. Moreover, there was no difference in the emission intensity at 368 nm among suspensions of the various morphological states of the cells. A calibration curve of the fluorescence emission intensities. and cell mass was obtained with a high correlation ($R^2=0.9938$) for the various morphological forms of H. pluvialis. Accordingly, the proposed method showed no significant dependency on the various morphological cell forms, making it applicable for cell-mass measurement. A high correlation was found between the fluorescence emission intensities and the dry cell weight with a mixture of green, green-brown, brown-red, and red cells. In conclusion, the proposed model can be directly used for cell-mass sensing without any pretreatment and has potential use as a noninvasive method for the online determination of algal biomass.

Analysis and Conservation of Historic Textiles - Theory and Practice - (섬유 문화재의 분석과 보존처리 - 이론과 실제 -)

  • Oh, Joon-Suk
    • Journal of the Korean Society of Costume
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    • v.58 no.5
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    • pp.211-231
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    • 2008
  • To conserve historic textiles, analyses of textile materials, pollutants and deterioration are prerequisite steps. Based upon analytical results, guides for conservation of historic textiles are established. In analyses of textile materials, pollutants and deterioration, there are chemical methods(burning, solubility and staining), physical methods(microscopy and density) and instrumental analysis(Fourier Transform Infrared Spectroscopy (FT-IR), Fourier Transform Raman Spectroscopy(FT-Raman), Gas Chromatography(GC), Mass Spectroscopy(MS), X-Ray Fluorescence (EDXRF, WDXRF), Energy Dispersive Spectroscopy(EDS), and X-Ray Diffraction(XRD), Tensile Testing Machine etc.). Combination of qualitative and quantitative analyses makes accurate diagnosis of textile condition possible. As examples of analyses and conservation of historic textiles, Chuninsan(19 century) similar to sunshade with handing down historic textile and golden decorative skirt(17 century) with excavated costume are taken.

Applications of Isotope Ratio Infrared Spectroscopy (IRIS) to Analysis of Stable Isotopic Compositions of Liquid Water (동위원소비 적외선 분광법(IRIS)을 이용한 물 안정동위원소 분석)

  • Jung, Youn-Young;Koh, Dong-Chan;Lee, Jeonghoon;Ko, Kyung-Seok
    • Economic and Environmental Geology
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    • v.46 no.6
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    • pp.495-508
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    • 2013
  • Recently, stable isotopes (${\delta}^{18}O$ and ${\delta}D$) of water are increasingly analyzed using laser-based technologies. These methods have advantages over Isotope Ratio Mass Spectrometry (IRMS) in that they can be used for in-situ measurements and require much less maintenance and preparation work. Two types of laser-based methods are currently available, which have different analytical principles; OA-ICOS (off-axis integrated cavity output spectroscopy) and WS-CRDS (wavelength-scanned cavity ring-down spectroscopy). In the WS-CRDS instrument, water is vaporized at controlled environment and transferred to an optical cavity by nitrogen carrier gas, and stable isotopic compositions of water vapor are measured using the degree of absorbance of specific wavelengths and the ratios of attenuation time of the laser intensity with the sensitivity of ppb to tens of ppt level. In this study, we introduce the principle of the WS-CRDS technology and the performance results including stability and comparisons with Isotope Ratio Mass Spectrometry (IRMS) and suggest possible applications of various topics in isotope hydrology.