• Journal of Magnetics
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• v.5 no.4
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• pp.120-123
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• 2000

Co-Ni-Fe-N thin films were fabricated by a $N_2$ reactive rf magnetron sputtering method. The nitrogen partial pressure ($P_{N2}$) was varied in the range 0~10% . As$P_{N2}$ increases in this range, the saturation magnetization $B_s$ linearly decreases from 19.8 kG to 14 kG and the electrical resistivity ($\rho$) increases from 27 to 155 $\mu\Omegacm$. The coercivity $H_c$ exhibits the minimum value at 4% $P_{N2}$. The magnetic anisotropy fields ($H_k$) are in the range of 20$\sim$50 Oe. High frequency characteristics of $(Co_{22.2}Ni_{27.6}Fe_{50.2})_{100-x}N_x$ films are excellent in the range of 3$\sim$5% of $P_{N2}$. In particular, the effective permeability of the film fabricated at 4% $P_{N2}$ is 800, which is maintained up to 600 MHz. This film also shows Bs of 17.5 kG, $H_c$/ of 1.4 Oe, resistivity of 98$\mu\Omegacm$ and $H_k$ of about 25 Oe. Also, the corrosion resistance of $(Co_{22.2}Ni_{27.6}Fe_{50.2})_{100-x}N_x$ films was imp roved with increasing N concentration.

• Proceedings of the Korean Magnestics Society Conference
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• 2000.09a
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• pp.492-499
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• 2000

Co-Ni-Fe-N thin films were fabricated by a N$\sub$2/ reactive rf magnetron sputtering method. The nitrogen partial pressure (P$\sub$N2/) was varied in the range of 0∼10%. As P$\sub$N2/ increases in this range, the saturation magnetization (B$\sub$s/) linearly decreases from 19.8 kG to 14 kG and the electrical resistivity ($\rho$) increased from 27 to 155 ${\mu}$$\Omega$cm. The coercivity (H$\sub$c/) exhibits the minimum value at 4% of P$\sub$N2/. The magnetic anisotropy (H$\sub$k/) are in the range of 20∼50 Oe. High frequency characteristics of (Co$\sub$22.2/Ni$\sub$27.6/Fe$\sub$50.2/)$\sub$100-x/N$\sub$x/ films are excellent in the range of 3∼5% of P$\sub$N2/. Especially the effective permeability of the film fabricated at 4% of P$\sub$N2/ is 800, which is maintained up to 600 MHz. This film also shows Bs of 17.5 kG, H$\sub$c/ of 1.4 Oe, resistivity of 98 $\Omega$cm and H$\sub$k/ of about 25 Oe. Also, the corrosion resistance of (Co$\sub$22.2/Ni$\sub$27.6/Fe$\sub$50.2/)$\sub$100-x/N$\sub$x/ were improved with the increase in N concentration.

• Journal of the Korean Magnetic Resonance Society
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• v.27 no.2
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• pp.5-9
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• 2023

t ENOD40B, a plant peptide hormone, was doubly labeled with C-13 and N-15 by recombinant production in Escherichia coli. The peptide was prepared by affinity chromatography followed by protease cleavage and reverse-phase chromatography. To elucidate the mode of action against its receptor, sucrose synthase, we proceeded to assign the backbone and side-chain resonances using a set of double and triple resonance experiments. This result will be used to determine the three-dimensional structure of the peptide at its bound state as well as to observe the chemical shift changes upon binding.

• Bulletin of the Korean Chemical Society
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• v.27 no.11
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• pp.1801-1808
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• 2006

The interaction between whey carrier protein $\beta$-lactoglobulin type A and B (BLG-A and -B) and 2,2'-bipyridin n-hexyl dithiocarbamato Pd(II) nitrate (BPHDC-Pd(II)), a new heavy metal complex designed for anticancer property, was investigated by fluorescence spectroscopy combined with chemometry and circular dichroism (CD) techniques. A strong fluorescence quenching reaction of BPHDC-Pd(II) to BLG-A and -B was observed. Hence, BPHDC-Pd(II) complex can be bound to both BLG-A and -B, and quench the fluorescence spectra of the proteins. The quenching constant was determined using the modified Stern-Volmer equation. The binding parameters were evaluated by fluorescence quenching method. The results of binding study provided evidences presence of two and three sets of binding sites on the BLG-B and -A, respectively, for BPHDC-Pd(II) complex. Using fluorescence spectroscopy and chemometry, the ability of BLG-A and -B to form an intermediate upon interaction with BPHDC-Pd(II) complex was assessed. CD studies displayed that under influence of different concentrations of BPHDC-Pd(II) complex, the regular secondary structure of BLG-B had no significant changes, whereas for BLG-A a transition from $\alpha$-helix to $\beta$-structure was appeared. The results for both of BLG-A and -B displayed that BPHDC-Pd(II) complex can induce a conformational transition from the native form to an intermediate state with a slightly opened conformation, which is detectable with chemometry analyses.

• Journal of the Korean Ceramic Society
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• v.29 no.12
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• pp.942-948
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• 1992

Ultrafine iron oxide powder, {{{{ gamma }}-Fe2O3 and $\alpha$-Fe2O3, were prepared by the thermal decomposition of organometallic compounds. The formation process of powder includes the thermal decomposition and oxidation of the organometallic precursors, Fe(N2H3COO)2(N2H4)2 (A) and N2H5Fe(N2H3COO)3.H2O (B). The organometallic precursors, A and B, were synthesized by the reaction of ferrous ion with hydrazinocarboxylic acid, and characterized by quantitative analysis and infrared spectroscopy. The mechanistic study for the thermal decomposition was performed by DAT-TG. The iron oxide powder was obtained by the heat treatment of the precursors at 20$0^{\circ}C$ and $600^{\circ}C$ for half an hour in air. The phases of the resulting product were proved {{{{ gamma }}-Fe2O3 and $\alpha$-Fe2O3 respectively. The particle shape was equiaxial and the particle size was less than 0.1 ${\mu}{\textrm}{m}$. Magnetic properties of the {{{{ gamma }}-Fe2O3 powder obtained from A and B was 234 Oe of coercivity, 64.26 emu/g of saturation magnetization, 23.59 emu/g of remanent magnetization and 24.1 Oe, 47.27 emu/g, 3.118 emu/g respectively. The value of $\alpha$-Fe2O3 powder was 1.494 Oe, 0.4862 emu/g, 0.1832 emu/g and 1,276 Oe, 0.4854 emu/g, 0.1856 emu/g respectively.

• Microbiology and Biotechnology Letters
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• v.28 no.1
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• pp.14-20
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• 2000

The transformation of Bacillus subtilis K-54 and J-10 was carried out with constructed vectors containing structure and enhancer genes of aprN and prtR, to increase their fibrinolytic enzyme activity. Bands for the aprN and prtR genes were identified from B. subtilis J-10 by PCR that was carried out with the constructed primers for the genes. In addition, the gene fragments contained promoter site based on the results of analysing their nucleotide sequence. The two gene fragments, aprN and prtR, obtained by the PCR, were, then, inserted to vector such as T-vector and E.coli/Bacillus shuttle vector. The constructed vector were designated as pAPR2 (aprN), pENC2 (prtR) and pFLA1 (aprN and prtR), respectively. The constructed vector was used for transformation of the strains of B.subtilis J-10 and B. subtilis K-54 and the fribrinolytic activity of the transformed strains was investigated. The introduction of the vector, pAPR2 and the fibrinolytic activity of the transformed strains was investigated. The introduction of the vector, pAPR2 and pFLA1, resulted in the increase of fibrinolyitic enzyme activity in B. subtilis J-10 by 27.3% and 16%, respectively. However, the introduction of pENC2 to B. subtilis J-10 did not seem to induce increase of the enzyme activity. The strain of B.subtilis K-54 transformed with pENC2 showed an increased fibrinolytic activity by 5 folds compared with that of the original strain of B. subtilis K-54.

• Bulletin of the Korean Chemical Society
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• v.27 no.7
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• pp.1005-1008
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• 2006

The reaction of $AgClO_{4}$ with acyclic potential tridentate N,N,N',N',N''-pentamethyldiethylenetriamine (pmdeta) has given colorless crystals suitable for X-ray crystallography. The crystal structure ($P2_{1}$/n, a = 14.413(1) $\AA$, b = 25.270(2) $\AA$, c = 16.130(1) $\AA$, b = $103.012(1){^{\circ}}$, V = 5723.7(8) A$\AA^{3}$, Z = 4, R = 0.0349) has been solved and refined. Three silver(I) ions connect four pmdeta ligands to produce discrete complex of $[Ag_3(pmdeta)_4](ClO_4)_3$. A pmdeta ligand is bridged to three silver(I) ions, and three other pmdeta ligands are chelated to each silver(I) center in a tridentate mode. Thus, the product is a rare tri-nuclear silver(I) complex with two different chemical environments. $^{13}C$ NMR and $MAS\;^{13}$C NMR indicate that the tri-nuclear silver(I) complex is not rigid in solution. The contact angles and thermal analyses of the complex are measured and discussed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.3
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• pp.226-232
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• 1982

The measurements of the jerking force and the tail beat by hooked carp were carried out using a strain gauge at a fish pond from July to August 1981. The maximum jerking force was sustained for a while in the initial state after a carp was hooked, but the jerking force was gradually decreased as a function of the time elapsed until the fish was utterly exhausted, and it converged to the body weight at last. The results are as follows : 1. The maximum jerking force $F_m(g)$ can be expressed with empirical formula : $$F_m=3.23W+105$$ where W (g) is the body weight. 2. Dynamic change of the maximum jerking force $F_n(g)$ by one tail beat with time $t_{n}(-10T/2{\leq}\;t_n{\leq}10T/2)$ can he induced with the equation as follows : $$F_n=(0.27W-6.52)(|t_n|+C)^{-2.10}$$ where the period T (sec) is given by the following equation with the body weight : T=0.000385W+0.193 3. The jerking force at each of the peak points $F_p$ (g) varies with the time elapsed t (sec) as following equation : $$F_{p}=(2.23W+105)e^{-{\beta}t}+W$$. The value of durability index $\beta$ was nearly zero in the initial state and about 1.7 in the exhausted state at last. 4. It was clearly shown that the change of jerking force by hooked carp was closely related to the tail beat from a paired difference T-test.

• The Korean Journal of Ecology
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• v.27 no.2
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• pp.93-98
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• 2004

Decay rate and nutrient dynamics during decomposition of oak (Quercus acutissima) branches were investigated for 33-months in Kongju, Korea. After 33-months, remaining weight of B₁, B₂ and B₃ was 44.5%, 58.5% and 55.37%, respectively. Decomposition constant (k) for B₁, B₂ and B₃ was 0.294/yr, 0.195/yr, 0.215/yr, respectively. N concentration in decomposing oak branches increased in all diameter classes. After 33-months, remaining N in B₁, B₂ and B₃ was 101.2%, 91.9%, 104.4%, respectively. P concentration in decomposing oak branches increased in B₁ and B₂, and there was no immobilization period. After 33-months, remaining P in B₁, B₂ and B₃ was 57.2%, 74.4%, 53.9%, respectively. K concentration in decomposing oak branches decreased significantly. Remaining K in B₁, B₂ and B₃ was 7.7%, 17.1% and 17.2%, respectively, which was significantly lower than other nutrients. Ca concentration in decomposing oak branches increased in B₂ and B₃. After 33-months, remaining Ca in B₁, B₂ and B₃ was 58.5%, 47.8% and 75.2%, respectively. Initial concentration of Mg in oak branch was higher in smaller diameter class. After 33-months, remaining Mg in B₁, B₂ and B₃ was 44.3%, 57.9% and 47.7%, respectively.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.1
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• pp.32-36
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• 2001

To investigate epithelial cell proliferation reactivity in the odontogenic cysts, the expression of c-erbB-2 oncoprotein by epithelial lining was studied in odontogenic keratocyst(OKC, n=10), dentigerous cyst(DC, n=12), radicular cyst(RC, n=12) and normal dental follicle(n=7). The c-erbB-2 immunoreactivity was studied using a streptavidine- biotin- peroxidase method with polyclonal rabbit antihuman antibody to c-erbB-2 oncoprotein which is known to react with formalin fixed, paraffin-embedded sections and the intensity of staining was determined by manually. In all of 10(100%) OKCs, showed positive expression for c-erbB-2 oncoprotein compared with 10/12(83.3%) in DCs, 11/12(91.7%) in RCs and 5/7(71.4%) in normal dental follicles. The expression within OKC was higher than that of DC, RC and dental follicle but statistically not significant(p>0.05) and but may reflects underlying genetic defect. These results demonstrate differences in c-erbB-2 expression between the epithelial linings of the three major odontogenic cyst types, indicating differences in proliferation activity and differentiation processes within these lesions. And, in particular, these results are able to explain the peculiar aggressive growth pattern of OKC.