• Archives of Pharmacal Research
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• v.24 no.5
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• pp.390-396
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• 2001

Synthesized 6-arylamino-5,8-quinolinediones 4a-4j and 6-chloro-7-arylamino-5,8-isoquinolinediones 5a-5g were evaluated for effects on NAD(P)H quinone oxidoreductase (NQOl ) activity with the cytosolic fractions derived from cultured human lung cancer cells and their cytotoxicity in cultured several human solid cancer cell lines. The 5,8-quinolinediones 4 and 5,8-isoquinolinediones 5 affected the reduction potential by NQO1 activity and showed a potent cytotoxic activity against human cancer cell lines. The tested compounds 4a, 5c, 5f, and 5g were considered as more potent cytotoxic agents. The compounds 4d, 5b, 5c, 5e and 5g were comparable modulators of NQO1 activity.

• Journal of the Korean Ceramic Society
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• v.43 no.11 s.294
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• pp.693-699
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• 2006

Textured $Bi_{0.5}(Na,K)_{0.5}TiO_3-BiFeO_3$ ceramics were prepared by the reactive-templated grain growth process, using platelike $Bi_4Ti_3O_{12}$ particles. The effects of chemical composition in $Bi_{0.5}(Na,K)_{0.5}TiO_3$ on texture development and densification were examined. Textured ceramics were obtained by using $Bi_{0.5}K_{0.5}TiO_3$ as an end member of the solid solution but densification was limited. Dense ceramics were obtained by using $Bi_{0.5}Na_{0.5}TiO_3$ but texture did not develop. Dense, textured ceramics were obtained by using $Bi_{0.5}(Na_{0.5}K_{0.5})_{0.5}TiO_3$.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.9
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• pp.728-732
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• 2011

In this study, piezoelectric and dielectric properties of Lead-free $0.97[(K_{0.5}Na_{0.5})(Nb_{0.97}Sb_{0.03})O_3]+0.03[(Bi_{0.5}K_{0.5})TiO_3]$ (abbreviated as 0.97NKNS-0.03BKT)ceramics synthesized by conventional solid-state reaction process were investigated as a function of $K_{5.4}Cu_{1.3}Ta_{10}O_{29}$ addition. The results indicated that the $K_{5.4}Cu_{1.3}Ta_{10}O_{29}$ addition significantly improved the sinterability, grain growth and piezoelctric properties of 0.97NKNS-0.03BKT ceramics. The optimum values as planar piezoelectric coupling coefficient ($k_p$= 0.355), piezoelectric constant ($d_{33}$= 207 pC/N) and mechanical quality factor ($Q_m$= 128) were obtained when 0.009KCT was added. The electromechanical coupling factor($k_p$) was slightly decreased according to the increasing temperature.

• Journal of the Korean Magnetics Society
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• v.20 no.6
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• pp.207-211
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• 2010

We have investigated the magnetoresistance effect in $Cr_5S_6$ single crystals prepared by vapor transport method. Room temperature X-ray diffraction (XRD) study reveals the phase formation of the single crystals with trigonal crystal structure. The magnetization was measured as a function of temperature (5 K~400 K) and applied magnetic field (0.1 T and 5 T). The magnetization curve as a function of temperature reveals the two transition states of $Cr_5S_6$: one from antiferromagnetic to ferrimagnetic state at ~150 K and the other from ferrimagnetic to paramagnetic state at ~300 K. Temperature dependent resistivity at 0 T and 5 T magnetic field shows the metallic behavior, showing the transition from antiferromagnetic to ferrimagnetic state at ~150 K. Magnetic field dependence of magnetization was measured at four fixed temperatures viz. 100 K, 150 K, 200 K, and 300 K. It is observed that at 200 K and 300 K it shows well M-H hysteresis behavior, whereas at 100 K and 150 K it shows non-hysteretic nature. A negative magnetoresistance (MR) of -2% is observed at 5 T for $Cr_5S_6$ single crystal at 150 K, near the antiferromagnetic transition temperature.

• Biomolecules & Therapeutics
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• v.25 no.3
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• pp.315-320
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• 2017

We investigated the role of autophagy in SNUC5/5-FUR, 5-fluorouracil (5-FU) resistant SNUC5 colon cancer cells. SNUC5/5-FUR cells exhibited low level of autophagy, as determined by light microscopy, confocal microscopy, and flow cytometry following acridine orange staining, and the decreased level of GFP-LC3 puncta. In addition, expression of critical autophagic proteins such as Atg5, Beclin-1 and LC3-II and autophagic flux was diminished in SNUC5/5-FUR cells. Whereas production of reactive oxygen species (ROS) was significantly elevated in SNUC5/5-FUR cells, treatment with the ROS inhibitor N-acetyl cysteine further reduced the level of autophagy. Taken together, these results indicate that decreased autophagy is linked to 5-FU resistance in SNUC5 colon cancer cells.

• Journal of the Korean Chemical Society
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• v.35 no.3
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• pp.233-239
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• 1991

$N_1-alkyl-5-fluorouracil$ derivatives from 2-chloro-ethylacrylate(CEA) were synthesized. The reaction of 5-fluorouracil(5-FU) with 2-chloroethyl acrylate gave 1-hydroxyethyl-5-fluorouracil(HEFU) in 70% yield. The treatment of HEFU with acryloyl chloride afforded 1-acryloyloxyethyl-5-fluorouracil (AOEFU). Poly(1-acryloyloxyethyl-5-fluorouracil)[Poly(AOEFU)] was also synthesized from 5-fluorouracil and Poly(CEA). The hydrolysis rates of $N_1-alkyl-5-fluorouracil$ derivatives were observed by means of UV spectrophotometer at 265 nm in ethanol-water(1 : 1); k = the constant of hydrolysis rate, $k=1.38{\times}10^{-4}$/sec for HEFU, $k=9.25{\times}10^{-5}$/sec for AOEFU, $k=4.16{\times}10^{-5}$k = 4.16 ${\times}$ $10-5}sec$ for Poly(AOEFU). The differential thermal analysis and thermogravimetry of 5-fluorouracil derivatives have been discussed.

• Therapeutic Science for Rehabilitation
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• v.12 no.1
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• pp.37-49
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• 2023

Object : This study aimed to identify the factor structure of Korean-Child Behavior Checklist 1.5-5 Dysregulation Profile (K-CBCL 1.5-5 DP) in infants and toddlers with mental disorders and verify differences in K-CBCL 1.5-5 DP among the diagnosis groups. Methods : The participants were 265 mothers of infants and toddlers with mental disorders who completed K-CBCL 1.5-5 DP. The data was analyzed using AMOS 25.0 and SPSS 25.0. Results : First, the bifactor model was the most suitable for the factor structure of the K-CBCL 1.5-5 DP. Second, there were significant differences among the diagnosis groups, such as communication disorders, pervasive developmental disorders, emotional disorders, and developmental delays. It was confirmed that the pervasive developmental disorder and emotional disorder groups showed significantly higher dysregulation compared with the communication disorder group. Conclusion : This study confirmed that infants and toddlers had dysregulation problems. Using the bifactor model, the multidimensional nature of the K-CBCL 1.5-5 DP was assessed. It was also meaningful that dysregulation could contribute to onset and deepening of symptoms of pervasive developmental disorders and emotional disorders in infancy.

• Journal of Bio-Environment Control
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• v.12 no.4
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• pp.240-244
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• 2003

The purpose of this study was to investigate a proper $Ca^{2+}\;:\;K^+$ ratio in nutrient solution to produce marjoram and oregano by hydroponics. Two herbs were grown for 40 days with the $Ca^{2+}\;:\;K^+$ ratio of 3.5;13, 4.5:11(standard herb's nutrient solution), 5.5:9 and 6.5:7mM${\cdot}L^{-1}$ of herb's nutrient solution developed by European Vegetable R &D Center, Belgium. The ratio of 5.5:9, and 6.5:7 mM${\cdot}L^{-1}$ showed better results in growth of marjoram than other treatments. Vitamin C contents and amounts of esential oil were the highest in the ratio of 5.5:9 and 6.5:7, respectively. Inoregano, the growth and vitamin C contents were the highest in the ratio of 5.5:9 and 6.5:7 mM${\cdot}L^{-1}$, respectively. The content (%) and amount (mg/plant) of essential oil were the highest in the ratio of 6.5:7mM${\cdot}L^{-1}$. These results indicated that 5.5:9 and 6.5:7 mM${\cdot}L^{-1}$were proper $Ca^{2+}\;:\;K^+$ ratio of nutrient solution of marjoram and oregano, respectively, by hydropoinics.

• Korean Journal of Materials Research
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• v.18 no.9
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• pp.475-481
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• 2008

Positive temperature coefficient of resistivity (PTCR) characteristics of (1-x)$BaTiO_3-x(Bi_{0.5}K_{0.5})TiO_3$ ceramics doped with $Nb_2O_5$ were investigated in order to develop the Pb-free PTC thermistor available at high temperatures of > $120^{\circ}C$. The PTCR characteristics appearing in the ($B_{i0.5}K_{i0.5})TiO_3$ (< 5 mol%) incorporated $BaTiO_3$ ceramics, which might be mainly due to $Bi^{+3}$ ions substituting for $Ba^{+2}$ sites. The 0.99$BaTiO_3-0.01(Bi_{0.5}K_{0.5})TiO_3$ ceramics showed good PTCR characteristics of a low resistivity at room temperature (${\rho}_r$) of $31{\Omega}{\cdot}cm$ a high ${\rho}_{max}/{\rho}_{min}$ ratio of $5.38{\times}10^3$, and a high resistivity temperature factor (${\alpha}$) of $17.8%/^{\circ}C$. The addition of $Nb_2O_5$ to 0.99$BaTiO_3-0.01(Bi_{0.5}K_{0.5})TiO_3$ ceramics further improved the PTCR characteristics. Especially, 0.025 mol% $Nb_2O_5$ doped 0.99$BaTiO_3-0.01(Bi_{0.5}K_{0.5})TiO_3$ ceramics exhibited a significantly increased ${\rho}_{max}/{\rho}_{min}$ ratio of $8.7{\times}10^3$ and a high ${\alpha}$ of $18.6%/^{\circ}C$, along with a high $T_c$ of $148^{\circ}C$ despite a slightly increased ${\rho}_r$ of $31{\Omega}{\cdot}cm$.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.41 no.2
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• pp.122-128
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• 2005

The experiments were conducted to fine out the handling characteristics of the FMT(Frame Mideater Trawl) in the southern waters of Korea using a trawler "DONGBAEK" belongs to Yosu National University. The realtionship between the net depth D(m) and the warp length L(m) at the towing speeds of 2.5k't and 3.5k't werw as follows ; D(m) = 0.30L - 1.3(2.5k't), D(m) = 0.16L - 1.5(3.5k't). Therefore, the net depth was 3.0m deeper when the warp length was 10m longer at the towing speed of 2.5k't and was 1.6m deeper for 10m longer at the speed of 3.5k't, respectively. The sinking speed of FMT was 6.5m/min when the warp releasing speed was 24m/min at the towing speed of 2.5k't and was 3.8m/min for 25m/min at the towing speed of 3.5k't, respectively. The rising speed of FMT was 6.9m/min when the warp rewinding speed was 28m/min at the towing speed of 2.5k't and was 5.3m/min for 25m/min at the towing speed of 3.5k't, respectively. The mean elapsed time getting to the stable towing condition was 104sec at the towing speed of 2.5k't and was 105sec at the towing speed of 3.5k't, respectively, and there was no time difference for the towing speed variation. During the towing, the net depth was comparatively stable on the condition of no change for the warp length and the towing speed.