• 한국초전도학회:학술대회논문집
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• v.15
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• pp.35-35
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• 2005

• Tuberculosis and Respiratory Diseases
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• v.40 no.3
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• pp.236-249
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• 1993

Background: Among the injurious agents to which the lung airspaces are constantly exposed are reactive species of oxygen. It has been widely believed that reactive oxygen species may be implicated in the etiology of lung injuries. In order to elucidated how this oxidant causes lung cell injury, we investigated the effects of exogenous $H_2O_2$ on alveolar epithelial barrier characteristics. Methods: Rat type II alveolar epithelial cells were plated onto tissue culture-treated polycarbonate membrane filters. The resulting confluent monolayers on days 3 and 4 were mounted in a modified Ussing chamber and bathed on both sides with HEPES-buffered Ringer solution. The changes in short-circuit current (Isc) and monolayer resistance (R) in response to the exogenous hydroperoxide were measured. To determine the degree of cellular catalase participation in protection against $H_2O_2$ injury to the barrier, experiments were repeated in the presence of 20 mM aminotriazole (ATAZ, an inhibitor of catalase) in the same bathing fluid as the hydroperoxide. Results: These monolayers have a high transepithelial resistance (>2000 ohm-$cm^2$) and actively transport $Na^+$ from apical fluid. $H_2O_2$(0-100 mM) was then delivered to either apical or basolateral fluid. Resulting indicated that $H_2O_2$ decreased Isc and R gradually in dose-dependent manner. The effective concentration of apical $H_2O_2$ at which Isc (or R) was decreased by 50% at one hour ($ED_{50}$) was about 4 mM. However, basolateral $H_2O_2$ exposure led to $ED_{50}$ for Isc (and R) of about 0.04 mM. Inhibition of cellular catalase yielded $ED_{50}$ for Isc (and R) of about 0.4 mM when $H_2O_2$ was given apically, while $ED_{50}$ for basolateral exposure to $H_2O_2$ did not change in the presence of ATAZ. The rate of $H_2O_2$ consumption in apical and basolateral bathing fluids was the same, while cellualr catalase activity rose gradually with time in culture. Conclusion: Our data suggest that basolateral $H_2O_2$ may affect directly membrane component (e.g., $Na^+,\;K^+$-ATPase) located on the basolateral cell surface. Apical $H_2O_2$, on the other hand, may be largely degraded by catalase as it passes through the cells before reaching these membrane components. We conclude that alveolar epithelial barrier integrity as measured by Isc and R are compromised by $H_2O_2$ being relatively sensitive to basolateral (and insensitive to apical) $H_2O_2$.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.4 no.2
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• pp.88-91
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• 2008

A female patient (14 years-old) with mental retardation was scheduled for ambulatory general anesthesia to treat peri-apical abscess and multiple dental caries. She had got cleft palate plasty at 5 years, but there was no past history of difficulty airway during general anesthesia or airway obstruction. Following induction of anesthesia using an inhalational anesthetic technique, conventional naso-tracheal intubation was tried. However, with conventional intubation technique we could not insert tube. And following several trial of intubation with laryngoscope, she developed an upper airway obstruction. Her lungs could not be ventilated using a facial mask and oxygen saturation was decreased. A #3 laryngeal mask airway (LMA) was inserted immediately, which allowed us to ventilate her lungs and restore the oxygen saturation. And dental treatment was carried out under LMA insertion successfully.

• Bulletin of the Korean Chemical Society
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• v.26 no.4
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• pp.594-598
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• 2005

Treatment of a solution of $CuCl_2$ in dimethyl phosphate (DMP) with DMSO under nitrogen atmosphere afforded to a light blue fluorescence powder. Slow evaporation of $H_2O$-DMSO solution of this powder resulted in blue-sky crystals of a new polymeric Cu(II) complex, with a unit cell composed of $Cu_2(DMP)_4$(DMSO), (1). The crystal and molecular structure of the complex acquired crystallographically. Compound (1) crystallizes in the monoclinic space group $P2_1$/n with a = 12.8920(11) $\AA$, b = 13.1966(11) $\AA$, c = 14.7926(13) $\AA$, $\alpha$ = 90$^{\circ}$, $\beta$ = 98.943(2)$^{\circ}$, $\gamma$ = 90$^{\circ}$, V= 2486.1(4) ${\AA}^3$, and Z = 4. A square pyramidal environment for the metal center was established by coordination of oxygen atoms of four bridging DMP ligands in the basal positions and binding a tri-centered oxygen atom of DMSO in the apical disposition of Cu(II). The sixth position was also affected by a weak interaction with the sulfur atom of another DMSO. The phosphorous atom in the bridging DMP was arranged in a deformed tetrahedron with (gg) conformation for methyl esters with $C_{2v}$ symmetry.

• International Journal of Oral Biology
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• v.35 no.2
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• pp.43-49
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• 2010

Enterococcus faecalis, a gram-positive bacterium, has been implicated in endodontic infections, particularly in chronic apical periodontitis. Proinflammatory cytokines, including tumor necrosis factor-$\alpha$ (TNF-$\alpha$), are involved in the pathogenesis of these apical lesions. E. faecalis has been reported to stimulate macrophages to produce TNF-$\alpha$. The present study investigated the mechanisms involved in TNF-$\alpha$ production by a murine macrophage cell line, RAW 264.7 in response to exposure to E. faecalis. Both live and heat-killed E. faecalis induced high levels of gene expression and protein release of TNF-$\alpha$. Treatment of RAW 264.7 cells with cytochalasin D, an inhibitor of endocytosis, prevented the mRNA up-regulation of TNF-$\alpha$ by E. faecalis. In addition, antioxidant treatment reduced TNF-$\alpha$ production to baseline levels. Inhibition of extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein (MAP) kinase also significantly attenuated E. faecalis-induced TNF-$\alpha$ expression by RAW 264.7 cells. Furthermore, activation of NF-${\kappa}B$ and AP-1 in RAW 264.7 cells was also stimulated by E. faecalis. These results suggest that the phagocytic uptake of bacteria is necessary for the induction of TNF-$\alpha$ in E. faecalis-stimulated macrophages, and that the underlying intracellular signaling pathways involve reactive oxygen species, ERK, p38 MAP kinase, NF-${\kappa}B$, and AP-1.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.218-218
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• 2012

Recently, hexagonal manganites have attracted much attention because of the coexistence of ferroelectricity and antiferromagnetic (AFM) order. The crystal structure of hexagonal manganites consists of $MnO_5$ polyhedra in which $Mn^{3+}$ ion is surrounded by three oxygen atoms in plane and two apical oxygen ions. The Mn ions within Mn-O plane form a triangular lattice and couple the spins through the AFM superexchange interaction. Due to incomplete AFM coupling between neighboring Mn ions in the triangular lattice, the system forms a geometrically-frustrated magnetic state. Among hexagonal manganites, $YMnO_3$, in particular, is the best known experimentally since the f states are empty. In addition, for applications, $YMnO_3$ thin films have been known as promising candidates for non-volatile ferroelectric random access memories. However, $YMnO_3$ has low magnetic order temperature (~70 K) and A-type AFM structure, which hinders its applications. We have synthesized $YMn1_{-x}Cr_xO_3$ (x = 0, 0.05 and 0.1) samples by the conventional solid-state reaction. The powders of stoichiometric proportions were mixed, and calcined at $900^{\circ}C$ for $YMn1_{-x}Cr_xO_3$ for 24 h. The obtained powders were ground, and pressed into 5-mm-thick disks of 1/2-inch diameter. The disks were directly put into the oven, and heated up to $1,300^{\circ}C$ and sintered in air for 24 h. The phase of samples was checked at room temperature by powder x-ray diffraction using a Rigaku Miniflex diffractometer with Cu $K{\alpha}$ radiation. All the magnetization measurements were carried out with a superconducting quantum-interference-device magnetometer. Our experiments point out that the Cr-doped samples show the characteristics of a spin-glass state at low temperatures.

• Bulletin of the Korean Chemical Society
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• v.27 no.10
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• pp.1597-1600
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• 2006

The mononuclear iron complex 1, $Fe^{III}$(Hbida)Cl($H_2O$), was synthesized using a tripodal tetradentate ligand, N-(benzimidazol-2-ylmethyl)iminodiacetic acid (H3bida), which has two carboxylate groups, one benzimida- zoyl group, and one tertiary amine where it serves as a tetradentate chelating ligand for the octahedral Fe(III) ion. The four equatorial positions of the octahedral complex are occupied by two monodentate carboxylates, a benzimidazole nitrogen, and an oxygen of a water molecule. One of the axial positions is occupied by an apical nitrogen of the Hbida and the other by a chloride anion. The mononuclear octahedral complex 1 mimics the geometry of the key intermediate structure of the catalytic reaction cycle proposed for the FeSODs, which is a distorted octahedral geometry with three histidyl imidazoles, an aspartyl carboxylate, a superoxide anion, and a water molecule. The redox potential of complex 1, $E_{1/2}$ is -0.11V vs. Ag/AgCl (0.12 V vs. NHE), which is slightly lower than those reported for the most FeSODs. The magnetic susceptibility of complex 1 at room temperature is 5.83 $\mu$B which is close to that of the spin only value, 5.92 $\mu$B of high-spin d5 Fe(III).

• Journal of Korean Academy of Nursing
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• v.36 no.2
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• pp.255-264
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• 2006

Purpose: This study is aimed to confirm the effects of Yakson therapy on the growth and physical response of preform infants, and maternal attachment to them compared with GHT therapy. Method: The design of this study is nonequivalent control group with repeated measuring by quasi experimental study. The subjects are preterm infants in 26 - 34 gestational age hospitalized in the NICU of 4 university hospitals with an experimental group of 15 and a control group of 14. Yakson therapy consists of three phases: laying a hand, caressing by hand, and laying a hand again taking 5 minutes for each phase. Result: As a result of administering Yakson therapy to preform infants; the average weight gain of the Yakson group was higher than that of the GHT group, but there is no significant difference between groups. The oxygen saturation and maternal attachment difference between the Yakson and the GHT group were not significant. Significant differences in the average daily increase of oral intake and apical pulse rate were observed between the Yakson group and GHT group. Conclusion: These data suggested that Yakson therapy may be an effective nursing intervention which can facilitate growth and physical response of preform infants.

• Bulletin of the Korean Chemical Society
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• v.26 no.1
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• pp.72-76
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• 2005

Some mononuclear oxovanadium(IV) complexes having the general formula [VOL(bidentate)] (1-4) of which L is tridentate ONS-donor salicylaldehyde S-methyldithiocarbazate (sal-mdtc$^{2-}$) or salicylaldehyde 4- phenylthiosemicarbazate (sal-phtsc$^{2-}$) and bidentate stands for 2,2'-bipyridyl (bpy) or 1,10-phenanthroline (phen) have been synthesized. The complexes were characterized by elemental analyses, FAB mass, UV, IR spectroscopy, and cyclic voltammetry. Two of the complexes [VO(sal-mdtc)(bpy)] (1) and [VO(sal-mdtc) (phen)] (2) were crystallographically characterized. The structures revealed that vanadium atom is octahedrally coordinated by the O, N, and S donor atoms of the tridentate ligand, the two N atoms of bidentate ligand, and the oxo atom. The oxygen donor, occupying an apical position has a trans-labilizing effect, resulting in elongation of the V-N bond. The cyclic voltammograms of the complexes exhibited one cathodic response in the range −d1.45 $\sim$ −f1.52 V due to the reduction of V(IV) to V(III).

• Bulletin of the Korean Chemical Society
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• v.14 no.1
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• pp.137-143
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• 1993

The tetranuclear heterometallic complex CpMo$Os_3(CO)_{10}({\mu]-H)2[{\mu}3-{\eta}^2-C(O)CH_2Tol]\;(1,\;Cp={\eta}^5-C_5H_5,\;Tol=p-C_6H_4Me)$ has been examined by variable-temperature $^{13}$C-NMR spectroscopy and by a full three-dimensional X-ray structual analysis. Complex 1 crystallizes in the orthorhombic space group Pna2$_1$ with a = 12.960(1) ${\AA}$, b = 11.255(l) ${\AA}$, c = 38.569(10)${\AA}$, V = 5626(2) ${\AA}^3$ and ${\rho}$(calcd) = 2.71 gcm$^{-3}$ for Z = 8 and molecular weight 1146.9. Diffraction data were collectedon a CAD4 diffractometer, and the structure was refined to $R_F$ = 9.7% and $R_{W^F}$ = 9.9% for 2530 data (MoK${\alpha}$ radiation). There are two essentially equivalent molecules in the crystallographic asymmetric unit. The tetranuclear molecule contains a triangulated rhomboidal arrangement of metal atoms with Os(2) and Mo at the two bridgehead positions. The metal framework is planar; the dihedral angle between Os(l)-Os(2)-Mo and Os(3)-Os(2)-Mo planes is 180$^{\circ}$. A triply bridging (${\mu}_3,\;{\eta}^2$) acyl ligand lies above the Os(l)-Os(2)-Mo plane; the oxygen atom spans the two bridgehead positions, while the carbon atom spans one bridgehead position and an acute apical position. The molecular architecture is completed by an ${\eta}^5$-cyclopentadienyl ligand and a semi-triply bridging carbonyl ligand on the molybdenum atom, and nine terminal carbonyl ligands-four on Os(3), three on Os(l), and two on Os(2). The two hydride ligands are inferred to occupy the Os(l)-Os(2) and Mo-Os(3) edges from structural and NMR data.