• Journal of Biomedical Engineering Research
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• v.9 no.2
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• pp.149-152
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• 1988

From the analysis of proton NMR signals of human urine it is found that the signals corresponding to a phenolic compound of tyrosine are more frequently observed in cancer urine than in non-cancer urine. An effective reagent is obtained to detect the substance excreted in the urine and to find out a close connection with the result of the NMR analysis. An attempt is made to determine the reagent sensitivity and specificity for cancer diagnosis. The results of the attempt are respectively above 75% for both on an average.

• Bulletin of the Korean Chemical Society
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• v.34 no.8
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• pp.2413-2418
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• 2013

Forensic and legal medicine require reliable data to indicate excessive alcohol consumption. Ethanol is oxidatively metabolized to acetate by alcohol dehydrogenase and non-oxidatively metabolized to ethyl glucuronide (EtG), ethyl sulfate (EtS), phosphatidylethanol, or fatty acid ethyl esters (FAEE). Oxidative metabolism is too rapid to provide biomarkers for the detection of ethanol ingestion. However, the non-oxidative metabolite EtG is a useful biomarker because it is stable, non-volatile, water soluble, highly sensitive, and is detected in body fluid, hair, and tissues. EtG analysis methods such as mass spectroscopy, chromatography, or enzyme-linked immunosorbent assay techniques are currently in use. We suggest that nuclear magnetic resonance (NMR) spectroscopy could be used to monitor ethanol intake. As with current conventional methods, NMR spectroscopy doesn't require complicated pretreatments or sample separation. This method has the advantages of short acquisition time, simple sample preparation, reproducibility, and accuracy. In addition, all proton-containing compounds can be detected. In this study, we performed $^1H$ NMR analyses of urine to monitor the ethanol and EtG. Urinary samples were collected over time from 5 male volunteers. We confirmed that ethanol and EtG signals could be detected with NMR spectroscopy. Ethanol signals increased immediately upon alcohol intake, but decreased sharply over time. In contrast, EtG signal increased and reached a maximum about 9 h later, after which the EtG signal decreased gradually and remained detectable after 20-25 h. Based on these results, we suggest that $^1H$ NMR spectroscopy may be used to identify ethanol non-oxidative metabolites without the need for sample pretreatment.

• Journal of the Korean Magnetic Resonance Society
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• v.20 no.1
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• pp.7-12
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• 2016

PTMEG(Polytetramethylene ether glycol) is a polymer compound widely used as a wide range of applications in the textile industry. PTMEG substance carrying various 1,800~2,000 molecular weight are mainly used as the raw material of the spandex production. Molecular weight and degree of polymerization value for 4 different PTMEG samples under pilot plant scale synthetic process were determined by a new quantitative NMR method. In NMR experiments, p-toluenesulfonic acid(TSOH) was used for external standard material of PTMEG quantitative analysis. were measuring The concentration of the primary standard TSOH was measured by UV/Vis spectroscopy. By using NMR peak assignments and the integral values of designated proton NMR peaks, We were able to measure the % composition of the synthetic PTMEG polymers, concentrations, molecular weight and the degree of polymerization that show the synthetic process of each manufacturing pilot plant. By utilizing a newly developed quantitative NMR method were able to obtain the molecular weight of PTMEG samples within 0.08 error % range.

• BMB Reports
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• v.31 no.1
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• pp.89-94
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• 1998

The structures of the self-complementary decamer duplexes, $d(ACGTATACGT)_2$ (TATA-duplex) and $d(ACGTTAACGT)_2$, (TTAA-duplex) has been obtained in solution by proton NMR spectroscopy and restrained molecular dynamics. The duplexes are essentially B-type, with distortions apparent at the TATA and TTAA steps. Theses distortions and their effects on dynamics have been investigated by the measurement of imino proton exchange time of the base-pairs. The unusual opening kinetics of central A T base-pairs could be correlated to the abnormal structural properties of the corresponding sequences.

• Bulletin of the Korean Chemical Society
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• v.13 no.2
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• pp.140-145
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• 1992

The excited state intramolecular proton transfer and physical properties of 7-hydroxyquinoline are studied in various solutions and heterogeneous systems by measuring steady state and time-resolved fluorescence, reflection and NMR spectra. Proton transfer is observed only in protic solvents owing to its requirement of hydrogen-bonded solvent bridge for proton relay transfer. The activation energies of the proton transfer are 2.3 and 5.4 kJ/mol in $CH_3OH$ and in $CH_3OD$, respectively. Dimers of normal molecules are stable in microcrystalline powder form and undergo an extremely fast concerted double proton transfer upon absorption of a photon, consequently forming dimers of tautomer molecules. In the supercage of zeolite NaY, its tautomeric form is stable in the ground state and does not show any proton transfer.

• Investigative Magnetic Resonance Imaging
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• v.12 no.2
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• pp.107-114
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• 2008

Purpose : The aim of this study is to determine possibility of application of in vivo proton ($^1H$) magnetic resonance spectroscopy (MRS) in distinguishing cystic mass arising around pancreas by comparison of in vivo MRS, in vitro MRS using 3T MR machine, based on nuclear magnetic resonance (NMR). Materials and Methods : We obtained spectra of in vivo MRS, in vitro MRS and NMR from abdominal mass arising around pancreas (mucinous cystic neoplasm=5, intraductal papillary mucin producing tumor=5, pseudocyst=1, and lymphangioma=1). We estimated existence of peak of in vivo MRS, and in vitro MRS concordant to that of NMR. We also evaluated differential peak for predicting specific disease. Results : Correlation of presence of peak with NMR showed showed sensitivity of 29.6%, specificity of 82.6% and accuracy of 67.7% on in vivo MRS (p = 0.096, McNemar test), sensitivity of 57.1% and specificity of 92.6% and accuracy of 82.3% on in vitro MRS (p = 0.362, McNemar test). The spectra of NMR for IPMT showed more frequent peaks at 3.5-4.0 ppm (p=0.026). Conclusion : Although chemical analysis, using NMR could be regarded as possible tool to differentiate cystic masses, in vivo and in vitro MRS need further technical evolution for clinical application.

• Bulletin of the Korean Chemical Society
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• v.34 no.10
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• pp.2959-2962
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• 2013

As the concentration of aqueous $CD_3OH$ solutions was decreased, the OD peaks in $^2H$ NMR spectra grew relative to the $CD_3$ peaks. Isotope impurity for OH groups of $CD_3OH$ and deuterium naturally present in water contributed to the OD peaks. Using these peak area data, the site-specific isotope populations of isotope enriched chemicals were measured. In addition, the method using both $^1H$ and $^2H$ NMR spectroscopy was demonstrated with neat $CD_3OH$ to measure the site-specific isotope populations. The results indicate that although it represents only ~0.015% of hydrogen isotopes, the deuterium naturally present in solvents cannot be ignored, especially when the concentration of deuterium-enriched solutes is varied. Proton/deuteron exchange between methyl and methyl/hydroxyl groups was confirmed to be negligible, while that among hydroxyl groups was detectable.

• Journal of the Korean Magnetic Resonance Society
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• v.6 no.2
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• pp.94-102
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• 2002

An interesting recent application of intermolecular NOE experiment is the saturation transfer difference NMR(STD-NMR) method that is useful in screening compound libraries to identify bio-active ligands. This technique also identifies the group epitopes of the bound ligand in a reversibly forming protein-ligand complex. We present here a complete relaxation and conformational exchange matrix (CORCEMA) theory (Moseley et al., J. Magn. Reson. B, 108, 243-261 (1995)) applicable for the STD-NMR experiment. Using some ideal model systems we have analyzed the factors that influence the STD intensity changes in the ligand proton NMR spectrum when the resonances from some protons on the receptor protein are saturated. These factors will be discussed and some examples of its application in some model systems will be presented. This CORCEMA theory for STD-NMR and the associated algorithm are useful in a quantitative interpretation of the STD-NMR effects, and are likely to be useful in structure-based drug design efforts. They are also useful in a quantitative characterization of protein-protein (or protein-nucleic acid) contact surfaces from an intermolecular cross-saturation NMR experiment.

• Bulletin of the Korean Chemical Society
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• v.26 no.12
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• pp.2061-2064
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• 2005

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1999.12a
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• pp.346-351
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• 1999