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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Magnetic Resonance Society
Journal Basic Information
Journal DOI :
Korean Magnetic Resonance Society
Editor in Chief :
Oc Hee Han
Volume & Issues
Volume 5, Issue 2 - Dec 2001
Volume 5, Issue 1 - Jun 2001
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ESR Analysis of Cupric Ion Species Exchanged into NaH-ZSM-5 Gallosilicate
Yu, Jong-Sung ; Kim, Jeong-Yeon ;
Journal of the Korean Magnetic Resonance Society, volume 5, issue 1, 2001, Pages 1~12
ZSM-5 gallosilicate molecular sieves was synthesized and cupric ion was ion-exchanged into the gallosilicate. The locations of Cu(ll) species in the framework and their interactions with various adsorbates were characterized by combined electron spin resonance(ESR) and electron spin echo modulation(ESEM) methods. It was found that in a fresh hydrated material, Cu(II) is octahedrally coordinated to six water molecules. This species is located in the channel intersections of two sinusoidal channels and rotates rapidly at room temperature. Evacuation removes some of these water molecules, leaving the Cu(II) coordinated to less water molecules and anchored to of oxygens in the channel wall. Dehydration produces two Cu(II) species, both of which are located in sites inaccessible to oxygen as evidenced by non-broadening of its ESR lines by oxygen. Adsorption of adsorbate molecules such as water, alcohols, ammonia, acetonitrile and ethylene on dehydrated CuNaH-ZSM-5 gallosilicate materials causes changes in the ESR spectrum of Cu(II), indicating the migration of Cu(II) into main channels to form complexes with these adsorbates there. Cu(II) forms a complex with two molecules of methanol, ethanol and propanol, respectively as evidenced by ESR parameters and ESEM data. Cu(II) also forms a square planar complex with four molecules of ammonia, based on the resolved nitrogen superhyperfine interactions and their ESEM parameters. Cu(II) forms a complex with two molecules of acetonitrile based on the ESR parameters and ESEM data. Interestingly, however, only part of Cu(II) interacts indirectly with one molecule of nonpolar ethylene based on ESR and ESEM analyses.
Determination of Alpha Defect Center in the Nature Using EPR Spectroscopy
Cho, Young-Hwan ; Hyun, Sung-Pil ; Pilsoo Hahn ;
Journal of the Korean Magnetic Resonance Society, volume 5, issue 1, 2001, Pages 13~18
Natural alpha radiation produced a stable defect center to certain minerals. Electron Paramagnetic Resonance(EPR) spectroscopy is a powerful tool f3r quantifying this defect center. EPR method has been applied to trace alpha-radiation effect around the uranium ore deposit. The results show that EPR technique can be used to measure rapidly and nondestructively the defect center produced by natural alpha radiation. In general, a good correlation was achieved between defect center concentration and actinide elements(U, Th). These results imply that the concentration of defect center is dependent on the alpha radiation dose over long time scale.
Solid-state NMR Studies of Miscibility and Morphology in Blends of Bisphenol-A type Polycarbonate and Poly (ester-ether) Elastomer
Kim, Yongae ;
Journal of the Korean Magnetic Resonance Society, volume 5, issue 1, 2001, Pages 19~28
Miscibility and morphology in blends of bisphenol-A type polycarbonate and poly (ester-ether) elastomer with different compositions are studied by solid-state NMR spectroscopy.
C Solid-state NMR of CP/MAS/TOSS/DD, CP/MAS/DD, inversion recovery CP/MAS/DD, and 2D rotor driven spin diffusion techniques are used to identify the miscibility, morphology, and transesterification in blends. The blends of PC /BT elastomer with 15% to 42% of soft segment seem to be single phase miscible mixing and those of PC/PBT and PC/PBT elastomer with 62% of soft segment are cocontinuous two phase immiscible mixing. No significant transesterification reactions are observed in blends with different compositions.
Application of multi dimensional NMR experiments to VBS RNAs of Yeast Saccaromyces cerevisiae virus
Chaejoon Cheong ; Cheong, Hae-Kap ; Yoo, Jun-Seok ;
Journal of the Korean Magnetic Resonance Society, volume 5, issue 1, 2001, Pages 29~36
The structures of two VBS (viral binding site) RNAs, SL1 and SL2, of Yeast Saccharomyces cerevisiae vims have been studied by 2D and 3D NMR experiments. VBSs play a crucial role in viral particle binding to the plus strand and packaging of the RNA. The secondary structures of the two VBS RNAs share a common feature of the stem-internal loop-stem-hairpin loop structure although the size of the internal loops of SL1 and SL2 differs. 2D experiments were sufficient for fill assignments of SL1. However, isotope labeling of the sample and multidimensional experiments were required for 28-nucleotide-long SL2 due to the spectral overlap. Several 3D HCCH experiments have accomplished full assignment of SL2 RNA.
Structure studies of Pulmonary Surfactant Protein B(SP-B(3,4)) by NMR Spectroscopy and Molecular Modeling
Kim, Yangmee ; Dongha Baek ; Kang, Joo-Hyun ; Shin, Song-Yub ; Hahm, Kyung-Soo ;
Journal of the Korean Magnetic Resonance Society, volume 5, issue 1, 2001, Pages 37~45
Synthetic pulmonary surfactants consisting of a mixture of phospholipids with synthetic peptides based on human surfactant-associated protein SP-B were prepared. These surfactants were analyzed f3r their secondary structures by circular dichroism (CD) spectroscopy and NMR spectroscopy. Two synthetic peptides (SP-B(3), SP-B(4)) combined with the phospholipid mixture displayed significant surfactant properties. The CD spectra showed that the u-helical propensities of the peptides in DPC micelles. In the NMR spectroscopy, the tertiary structures of SP-B(3) show that it has
-helical structure from Gln5 to Arg13 in DPC micelle and SP-B(4) show that they have
-helical structure from Gln5 to Leu12 in DPC micelle. Based on these structures, truncated peptides originated from SP-B protein, can be designed as effective synthetic surfactants for clinical use.
Structural Characterization of Growth-Related Translationally Controlled Tumor Protein P23
Lee, Bong-Jin ; Hong, Yoon-Hun ; Park, Sang-Ho ; Lee, Kyunglim ;
Journal of the Korean Magnetic Resonance Society, volume 5, issue 1, 2001, Pages 46~55
P23, a translationally controlled turner protein is involved in the interleukin-4 secretion from human basophils and is also known to be an IgE-dependent histamine-releasing factor. However, the precise physiological function and structure of P23 have not been elucidated. In the current study, we constructed the optimal expression and purification protocol of P23 and investigated the secondary structure and structural stability in various conditions. Circular dichroism (CD) investigation showed that the secondary structure of P23 adopts mainly a P-sheet conformation. CD spectroscopy and differential scanning calorimetry revealed that P23 is fairly stable in the pH range of neutral and mild-basic conditions and in the temperature range of 10 - 50
. Since the thermal stability and the P-sheet content of P23 were decreased by the addition of Ca
2+/ ion, it could be suggested that Ca
2+/ion induces structural change by partially destabilizing the structure of P23. In addition various H experiments were monitored to solve the aggregation of P23. Den results will provide the preliminary structural information about P23.
Evaluation of Neuronal Dysfunction in Schizophrenia before and after Neuroleptic Treatment by ？？H MRS
C, Bo-Young ; Paik, In-Ho ; Lee, Chang-Uk ; Lee, Hyoung-Koo ; Suh, Tae-Suk ;
Journal of the Korean Magnetic Resonance Society, volume 5, issue 1, 2001, Pages 56~65
Localized in vivo proton magnetic resonance spectroscopy (MRS) was performed to evaluate metabolic alterations in the right and left frontal lobe before and after neuroleptic treatment of schizophrenic patients (n=24) and a group of healthy normal subjects (n=20). Proton metabolic ratios obtained from the 8㎤ yokels in the right and left frontal lobe were compared with the clinical assessment of PANSS for each subject. There was no significant difference in the metabolic ratios between the right and the left frontal lobes in either the schizophrenic group or the control group, indicating no laterality. Compared with those of the normal control group, NAA/Cr and (GABA+Glu)/Cr ratios of the schizophrenic patients showed significantly lower (p=0.023) and higher (p=0.005) value, respectively. The (GABA+Glu)/Cr ratio of the schizophrenic patients was generally decreased after neuroleptic treatment, while the NAA/Cr ratio was not changed. Significant correlation between the (GABA+Glu)/Cr ratio and the clinical symptom scores assessed by PANSS was established. The present study supports the “hypofrontality” hypothesis of schizophrenia on the basis of the altered metabolic ratios before and after neuroleptic treatment.