• Title/Summary/Keyword: ${\beta}$ phase

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Effects of glutathione s-transferase (GST) M1 and T1 polymorphisms on antioxidant vitamins and oxidative stress-related parameters in Korean subclinical hypertensive subjects after kale juice (Brassica oleracea acephala) supplementation

  • Lee, Hye-Jin;Han, Jeong-Hwa;Park, Yoo Kyoung;Kang, Myung-Hee
    • Nutrition Research and Practice
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    • v.12 no.2
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    • pp.118-128
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    • 2018
  • BACKGROUND/OBJECTIVES: Glutathione s-transferase (GST) is involved in the formation of a multigene family comprising phase II detoxification enzymes, involved in the detoxification of reactive oxygen species. This study evaluated whether daily supplementation with kale juice could modulate levels of plasma antioxidant vitamins and oxidative stress-related parameters. We further examined whether this modulation was affected by combined GSTM1 and T1 polymorphisms. SUBJECTS/METHODS: Totally, 84 subclinical hypertensive patients having systolic blood pressure (BP) over 130 mmHg or diastolic BP over 85 mmHg, received 300 mL of kale juice daily for 6 weeks. Blood samples were drawn before start of study and after completion of 6 weeks. RESULTS: After supplementation, we observed significant decrease in DNA damage and increase in erythrocyte catalase activity in all genotypes. Plasma level of vitamin C was significantly increased in the wild/null and double null genotypes. The plasma levels of ${\beta}-carotene$, erythrocyte glutathione peroxidase activity, and nitric oxide were increased only in the wild/null genotype after kale juice supplementation. CONCLUSIONS: The effect of kale juice was significantly greater in the GSTM1 null genotype and wild/null genotype groups, suggesting possibility of personalized nutritional prescriptions based on personal genetics.

Study of Basic Properties to Develope SiC Ceramic Heater by Self-Charge with Electricity (자기 통전식 SiC세라믹 발열체 개발을 위한 기초 특성 연구)

  • Shin, Yong-Deok;Ko, Tae-Hun;Ju, Jin-Young
    • Proceedings of the KIEE Conference
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    • 2007.11a
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    • pp.124-125
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    • 2007
  • The composites were fabricated $\beta$-SiC and $TiB_2$ powders with the liquid forming additives of 8, 12, 16[wt%] $Al_2O_3+Y_2O_3$ as a sintering aid by pressureless annealing at $1,650[^{\circ}C]$ for 4 hours. Reactions between SiC and transition metal $TiB_2$ were not observed in the microstructure and the phase analysis of the pressureless annealed SiC-$TiB_2$ electroconductive ceramic composites. The relative density, the flexural strength, the Young's modulus and the Vicker's hardness showed the highest value of 82.29[%], 189.5[MPa], 54.60 [GPa] and 2.84[GPa] for SiC-$TiB_2$ composites added with 16[wt%] $Al_2O_3+Y_2O_3$ additives at room temperature. The relative density of SiC-$TiB_2$ composites was lowered due to gaseous products of the result of reaction between SiC and $Al_2O_3+Y_2O_3$. The electrical resistivity showed the lowest value of 0.012[${\Omega}{\cdot}cm$] for 16[wt%] at 25[$^{\circ}C$]. The electrical resistivity was all negative temperature coefficient resistance (NTCR) in the temperature ranges from 25[$^{\circ}C$] to 700[$^{\circ}C$].

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Antibacterial Properties of $Ag_2-Li_2O-CaO-TiO_2-P_2O_5$Porous Class Ceramics ($Ag_2-Li_2O-CaO-TiO_2-P_2O_5$계의 다공성 글라스 세라믹스의 항균 특성)

  • Kang, Won-Ho;Yoon, Young-Jin;Lee, Yong-Soo;Hong, Bum-Soo;Yeom, Gon;Kim, Chang-Soo;Seok, Man-Kyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.1 no.1
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    • pp.27-32
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    • 2000
  • Porous glass ceramics composed of $Ag_2-Li_2O-CaO-TiO_2-P_2O_5$-CaO with 0.05-1.5 mole CuO were prepared by melting and 2 step heat treatment for nucleation at $610^{\circ}C$ and crystallization at $840^{\circ}C$. $\beta$-$Ca_3(PO_4)_2$crystal phase was selectively leached out in 1N-HC1 solution for 3 days, leaving $AgTi_2(PO_4)_3$and $LiTi_2(PO_4)_3$crystal phases. Antibacterial effects and characterizations of the porous glass ceramics were investigated. Staphylococcus aureus and Salmonella typhi bacteroa were used in this study. It was found that the resultant porous glass ceramics show excellent bacteriostatic properties.

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Electrical Properties of SiC Composites by Transition Metal (천이금속에 따른 SiC계 복합체의 전기적 특성)

  • Shin, Yong-Deok;Seo, Je-Ho;Ju, Jin-Young;Ko, Tae-Hun;Kim, Young-Bek
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.1303-1304
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    • 2007
  • The composites were fabricated, respectively, using 61[vol.%]SiC-39[vol.%]$TiB_2$ and using 61[vol.%]SiC-39[vol.%]$ZrB_2$ powders with the liquid forming additives of 12[wt%] $Al_{2}O_{3}+Y_{2}O_{3}$ by hot pressing annealing at $1650[^{\circ}C]$ for 4 hours. Reactions between SiC and transition metal $TiB_2$, $ZrB_2$ were not observed in this microstructure. ${\beta}{\rightarrow}{\alpha}$-SiC phase transformation was occurred on the SiC-$TiB_2$ and SiC-$ZrB_2$ composite. The relative density, the flexural strength and Young's modulus showed the highest value of 98.57[%], 226.06[Mpa] and 86.38[Gpa] in SiC-$ZrB_2$ composite at room temperature respectively. The electrical resistivity showed the lowest value of $7.96{\times}10^{-4}[{\Omega}{\cdot}cm]$ for SiC-$ZrB_2$ composite at $25[^{\circ}C]$. The electrical resistivity of the SiC-$TiB_2$ and SiC-$ZrB_2$ composite was all positive temperature coefficient resistance (PTCR) in the temperature ranges from $25[^{\circ}C]$ to $700[^{\circ}C]$. The resistance temperature coefficient of composite showed the value of $6.88{\times}10^{-3}/[^{\circ}C]$ and $3.57{\times}10^{-3}/[^{\circ}C]$ for SiC-$ZrB_2$ and SiC-$TiB_2$ composite in the temperature ranges from $25[^{\circ}C]$ to $700[^{\circ}C]$.

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Evaluation of the fabrications and properties of ultra-thin film for memory device application (메모리소자 응용을 위한 초박막의 제작 및 특성 평가)

  • Jeong, Sang-Hyun;Choi, Haeng-Chul;Kim, Jae-Hyun;Park, Sang-Jin;Kim, Kwang-Ho
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.06a
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    • pp.169-170
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    • 2006
  • In this study, ultra thin films of ferroelectric vinylidene fluoride-trifluoroethylene (VF2-TrFE) copolymer were fabricated on degenerated Si (n+, $0.002\;{\Omega}{\cdot}cm$) using by spin coating method. A 1~5 wt% diluted solution of purified vinylidene fluoride-trifluoroethylene (VF2:TrFE=70:30) in a dimethylformamide (DMF) solvent were prepared and deposited on silicon wafers at a spin rate of 2000~5000rpm for 30 seconds. After annealing in a vacuum ambient at $200^{\circ}C$ for 60 min, upper gold electrodes were deposited by vacuum evaporation for electrical measurement. X-ray diffraction results showed that the VF2-TrFE films on Si substrates had $\beta$-phase of copolymer structures. The capacitance on $n^+$-Si(100) wafer showed hysteresis behavior like a butterfly shape and this result indicates clearly that the dielectric films have ferroelectric properties. The typical measured remnant polarization (2Pr) and coercive filed (EC) values measured using a computer controlled a RT-66A standardized ferroelectric test system (Radiant Technologies) were about $0.54\;C/cm^2$ and 172 kV/cm, respectively, in an applied electric field of ${\pm}0.75\;MV/cm$.

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Induction of Apoptotic Cell Death by Methanol Extract of Houttuynia cordata Thunb. in A549 Human Lung Carcinoma Cells (어성초 메탄올 추출물에 의한 A549 인체 폐암세포 사멸유도에 관한 연구)

  • Hong, Su-Hyun;Park, Cheol;Hong, Sang-Hoon;Choi, Byung-Tae;Lee, Yong-Tae
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.20 no.6
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    • pp.1584-1592
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    • 2006
  • Houttuynia cordata Thunb, well known as 'E-Sung-Cho' in Korea, is traditional medicinal plant generally used in Oriental medicine therapy. We previously reported that the water extract of H. cordata inhibited cell proliferation and induced apoptosis in human breast carcinoma cells. In the present study, we investigated the biochemical mechanisms of anti-proliferative effects by the methanol extract of H. cordata (MEHC) in human lung carcinoma A549 cells. It was found that MEHC could inhibit the cell growth in a dose-dependent manner, which was associated with morphological change and apoptotic cell death as determined by formation of apoptotic bodies, DNA fragmentation and increased populations of apoptotic-sub G1 phase cells. Apoptosis of A549 cells by MEHC was also connected with a down-regulation of anti-apoptotic Bcl-2 and inhibitor of apoptosis proteins (IAPs) expression. MEHC treatment induced the proteolytic activation of caspase-3, caspase-8 and caspase-9, and a concomitant inhibition of poly(ADP-ribose) polymerase (PARP), ${\beta}$-catenin and phospholipase (PLC)-${\gamma}$1 protein expression. Taken together, these findings provide important new insights into the possible molecular mechanisms of the anti-cancer activity of H. cordata.

Anti-Proliferative Activity of Nodosin, a Diterpenoid from Isodon serra, via Regulation of Wnt/β-Catenin Signaling Pathways in Human Colon Cancer Cells

  • Bae, Eun Seo;Kim, Young-Mi;Kim, Dong-Hwa;Byun, Woong Sub;Park, Hyen Joo;Chin, Young-Won;Lee, Sang Kook
    • Biomolecules & Therapeutics
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    • v.28 no.5
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    • pp.465-472
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    • 2020
  • Colorectal cancer (CRC) is one of the most malignant type of cancers and its incidence is steadily increasing, due to life style factors that include western diet. Abnormal activation of canonical Wnt/β-catenin signaling pathway plays an important role in colorectal carcinogenesis. Therefore, targeting Wnt/β-catenin signaling has been considered a crucial strategy in the discovery of small molecules for CRC. In the present study, we found that Nodosin, an ent-kaurene diterpenoid isolated from Isodon serra, effectively inhibits the proliferation of human colon cancer HCT116 cells. Mechanistically, Nodosin effectively inhibited the overactivated transcriptional activity of β-catenin/T-cell factor (TCF) determined by Wnt/β-catenin reporter gene assay in HEK293 and HCT116 cells. The expression of Wnt/β-catenin target genes such as Axin2, cyclin D1, and survivin were also suppressed by Nodosin in HCT116 cells. Further study revealed that a longer exposure of Nodosin induced the G2/M phase cell cycle arrest and subsequently apoptosis in HCT116 cells. These findings suggest that the anti-proliferative activity of Nodosin in colorectal cancer cells might in part be associated with the regulation of Wnt/β-catenin signaling pathway.

Chiral Separation of the Enantiomers of Metoprolol and Its Metabolites by High Performance Liquid Chromatography

  • Kim, Kyeong-Ho;Shin, Sang-Duk;Lee, Joo-Hyun;Lee, Sang-Cheal;Kang, Jong-Seong;Mar, Woong-chon;Hong, Seon-Pyo;Kim, Hyun-Ju
    • Archives of Pharmacal Research
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    • v.23 no.3
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    • pp.230-236
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    • 2000
  • (1'R, 2R)-, (1'R, 2S)-, (1'S, 2R)- and (1'S, 2S)-$\alpha$-hydroxymetoprolol; (2R)- and (2S)-O-des-methylmetoprolol; and (2R)- and (2S)-metoprolol acid are major metabolites of (2R)-and (2S)-metoprolol, $\beta$-adrenergic antagonist. The focus of most chiral separation methods until now has been on determination of the enantiomeric parent drug. However, it is just as important to be able to follow the metabolism of the enantiomers and their possible chiral metabolites. Therefore, for the study of stereoselective metabolism and pharmacokinetics of metoprolol, the chiral separation of the enantiomers of metoprolol and its metabolites has been investigated using four chiral stationary phases, i.e., Chiralcel OD, Chiral-AGP, Cyclobond I and Sumichiral OA-4900 columns. Metoprolol acid was resolved only by Sumichiral OA-4900. Chiralcel OD provided the highest separation factor and resolution value for metoprolol and O-desmethylmetoprolol and partially resolved the four stereoisomers of $\alpha$-hydroxymetoprolol. Diastereomeric $\alpha$-hydroxymetoprolols were resolved using the coupled column chromatographic system of two chiral stationary phases, Sumichiral OA-4900 column and Chiralcel OD column.

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MICROMAGNETISM OF HARD AND SOFT MAGNETIC MATERIALS

  • Kronmuller, Helmut
    • Journal of the Korean Magnetics Society
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    • v.5 no.5
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    • pp.366-371
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    • 1995
  • High performance magnetic materials are characterized by the combination of outstanding magnetic properties and optimized microstructures, e.g., nanocrystalline composites of multilayers and small particle systems. The characteristic parameters of the hysteresis loops of these materials vary over more than a factor of $10^{6}$ with optimum values for the coercive field of several Tesla and permeabilities of $10^{6}$. Within the framework of the computational micromagnetism (nanomagnetism) using the finite element method the upper and lower bounds of the coercive field of different types of grain ensembles and multilayers have been determined. For the case of nanocrystalline composites the role of grain size, exchange and dipolar coupling between grains and the degree of grain alignment will be discusses in detail. It is shown that the largest coercivities are obtained for exchange decoupled grains, whereas remanence enhancing requires exchange coupled grains below 20 nm. For composite permanent magnets based on $Nd_{2}Fe_{14}B$ with an amount of ~ 50% soft $\alpha$-Fe-phase coercivities of ${\mu}_{0}H_{c}=0.75\;T$, a remanence of 1.5 T and an energy product of $400\;kJ/m^{3}$ is expected. In nanocrystalline systems the temperature dependence of the coercivity is well described by the relation ${\mu}_{0}H_{c}=(2\;K_{1}/M_{s}){\alpha}-N_{eff}{\mu}_{0}M_{s}$, where the microstructural parameters $\alpha$ and $N_{eff}$ take care of the short-range perturbations of the anisotropy and $N_{eff}$ is related to the long-range dipolar interactions. $N_{eff}$ is found to follow a logarithmic grain size size dependence ${\mu}_{0}H_{c}=(2\;K_{1}/M_{s}){\alpha}-N_{eff}(\beta1nD){\mu}_{0}M_{s}$. Several trends how to achieve the ideal situation $\alpha$->1 and $N_{eff}$->1->0 will be discussed.

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Tailoring the Dielectric and Mechanical Properties of Si3N4 Ceramics (질화규소 세라믹의 유전 및 기계적 특성 제어에 관한 연구)

  • Lee, Seung Jun;Yong, Seok-Min;Park, Jin-Woo;Choi, Jaeho;Baek, Seungsu
    • Journal of the Korea Institute of Military Science and Technology
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    • v.21 no.6
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    • pp.760-766
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    • 2018
  • The present study investigates the effect of PMMA and BN content on microstructure, mechanical and dielectric properties of silicon nitride($Si_3N_4$) ceramics in $Y_2O_3-Al_2O_3$ additive system. The total additive content was fixed at 8 wt.% and the amount of PMMA varies from 0 to 40 wt.% and BN varies from 0 to 36 wt.%, respectively. The crystalline phases of the samples were determined by X-ray diffraction analysis. All the sintered sample shows complete transformation of ${\alpha}$ to ${\beta}-Si_3N_4$ during the sintering process indicated that the phase transformation was unaffected by the PMMA or BN content. However, the microstructure shows that the residual porosity increased with increasing PMMA and BN content. In addition, the flexural strength and the dielectric constant decrease with addition of PMMA and BN due to the residual porosity. This article provides empirical study of design parameters for $Si_3N_4$-based radome materials.