• Bulletin of the Korean Mathematical Society
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• v.48 no.1
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• pp.115-127
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• 2011

We study the structure of the set of nilpotent elements in various kinds of ring and introduce the concept of NR ring as a generalization of Armendariz rings and NI rings. We determine the precise relationships between NR rings and related ring-theoretic conditions. The Kothe's conjecture is true for the class of NR rings. We examined whether several kinds of extensions preserve the NR condition. The classical right quotient ring of an NR ring is also studied under some conditions on the subset of nilpotent elements.

• Journal of the Korean Chemical Society
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• v.26 no.1
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• pp.31-35
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• 1982

Novel palladium(II) complexes of the type Pd(IBA-NH)(IBA-NH') and Pd(IBA-NR)2, where IBA-NH and IBA-NR (R: methyl, ethyl, n-propyl, n-butyl, benzyl) represent isonitrosobenzoylacetone imine and its N-alkyl derivatives respectively, have been prepared. The ir, nmr, and electronic spectra of the palladium(Ⅱ) complexes have been studied. It has been determined that the isonitroso group of IBA-NH coordinates to palladium through the oxygen to form 6-membered chelate ring and that of IBA-NH' coordinates to palladium through the nitrogen to form 5-membered ring in square-planar Pd(IBA-NH)(IBA-NH') and it also has been determined that the isonitroso groups of two IBA-NR coordinates to palladium through the nitrogen to form 5-membered rings in square-planar Pd$(IBA-NR)_2$. The coordination manner of the ligands is similar to that of isonitrosoacetylacetone imines obtained by Bose, et $al.^5$.

• Journal of the Korean Chemical Society
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• v.22 no.1
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• pp.19-24
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• 1978

Novel nickel(II) complexes of the type Ni(IBA-NH)(IBA-NR), where IBA-NH and IBA-NR (R=H, methyl, ethyl, n-propyl, iso-propyl, n-butyl or benzyl) represent isonitrosobenzoylacetone imine and its N-alkyl derivative respectively, have been prepared. The ir, nmr, and electronic spectra and magnetic moment of the nickel(II) complexes have been studied. It has been determined that the isonitroso group of IBA-NH coordinates to nickel through the oxygen to form 6-membered chelate ring and that of IBA-NR coordinates to nickel through the nitrogen to form 5-membered ring in square-planar Ni(IBA-NH) (IBA-NR). The coordination manner of the ligands is similar to that of isonitrosoacetylacetone imines obtained by Bose, et al.

• Bulletin of the Korean Chemical Society
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• v.9 no.4
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• pp.198-202
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• 1988

Several new palladium(II) complexes of aminophosphines, $(Pd(L)X_2)$, (L = $Ph_2PNH$ ++ $NR_2$; R = $CH_3(L_1)$, $C_2H_5(L_2)$ : X = Cl, Br, I, and NCS) that contain two different donor atoms of nitrogen and phosphorus as ${\pi}$-electron acceptor, were synthesized and characterized by conductivity measurement, ir, and UV/Vis-spectra. For the dithiocyanatopalladium(II) complexes with aminophosphines, it was confirmed that the thiocyanate group trans to phosphorus is coordinated as Pd-NCS mode and the one trans to nitrogen as Pd-SCN mode, and the aminophosphines form six-membered chelate ring. The spectra of dihalogenopalladium(II) complexes with aminophosphines show that the band maxima are shifted to the short wavelengths as the concentration is decreased.

• The Korean Journal of Pain
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• v.23 no.1
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• pp.1-10
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• 2010

Background: Recent studies indicate that reactive oxygen species (ROS) are involved in persistent pain, including neuropathic and inflammatory pain. Since the data suggest that ROS are involved in central sensitization, the present study examines the levels of activated N-methyl-D-aspartate (NMDA) receptors in the dorsal horn after an exogenous supply of three antioxidants in rats with chronic post-ischemia pain (CPIP). This serves as an animal model of complex regional pain syndrome type-I induced by hindpaw ischemia/reperfusion injury. Methods: The application of tight-fitting O-rings for a period of three hours produced CPIP in male Sprague-Dawley rats. Allopurinol 4 mg/kg, allopurinol 40 mg/kg, superoxide dismutase (SOD) 4,000 U/kg, N-nitro-L-arginine methyl ester (L-NAME) 10 mg/kg and SOD 4,000 U/kg plus L-NAME 10 mg/kg were administered intraperitoneally just after O-ring application and on the first and second days after reperfusion. Mechanical allodynia was measured, and activation of the NMDA receptor subunit 1 (pNR1) of the lumbar spinal cord (L4-L6) was analyzed by the Western blot three days after reperfusion. Results: Allopurinol reduced mechanical allodynia and attenuated the enhancement of spinal pNR1 expression in CPIP rats. SOD and L-NAME also blocked spinal pNR1 in accordance with the reduced mechanical allodynia in rats with CPIP. Conclusions: The present data suggest the contribution of superoxide, produced via xanthine oxidase, and the participation of superoxide and nitric oxide as a precursor of peroxynitrite in NMDA mediated central sensitization. Finally, the findings support a therapeutic potential for the manipulation of superoxide and nitric oxide in ischemia/reperfusion related pain conditions.

• Environmental Mutagens and Carcinogens
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• v.15 no.2
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• pp.131-139
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• 1995

Air suspedned particulates are the most serious factor among air pollutants in Seoul and their extracts have been revealed to be pulmonary carcinogenes. Air particulates were collected at a site representative of the high traffic area of Seoul from December 1993 to May 1994. Polycyclic aromatic hydrocarbons (PAHs) and nitroarenes in organic extracts of air particulates were determined by gas chromatography and mutagenicity of particle extracts was evaluated by the pre-incubation procedure with Salmonella typhirnurium TA98 and TA 98NR. The average concentration of total suspended particulates and inhalable (less than 10 $\mu$m) particulates were 169.63 $\mu g/m^3$, 141.92 $\mu g/m^3$, respectively. The relative contribution of organic matters was highest in neutral fraction and was lowest in basic fraction. Among identified 20 PAHs, the level of PAHs with 4-benzen ring i.e., pyrene, benzo(a)anthracene and chrysene were much higher than the PAHs with higher ring numbers. The mutagenicity of air particulates was much higher in the presence of rat liver microsomai fraction (S9 mixture) than that observed in its absence, which indicates that air particulates contained both direct and indirect mutagens. Nitroarenes in this study were not almost detected but mutagenicity of their fraction was higher. These results are represent to research for the identification of nitroarenes in the forward study.