• Title/Summary/Keyword: $LaB_6$

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Bioconversion of Linoleic Acid to Conjugated Linoleic Acid by Bifidobacterium breve

  • Song Yoon-Seok;Kang Seong-Woo;Oh Deok-kun;Rho Yong-Taik;Hong Suk-In;Kim Seung-Wook
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.10 no.4
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    • pp.357-361
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    • 2005
  • The bioconversion of linoleic acid (LA) to conjugated linoleic acid (CLA) was investigated to examine LA-adaptation of Bifidobacterium breve KCTC 3461 to additions of 1 to 5 mg/mL of LA overtime. To induce LA-adaptation, B. breve KCTC 3461 was treated with LA, according to three schemes. For LA-adapted B. breve the maximum concentration of CLA, $300\~350{\mu}g/mL$, was obtained in cys-MRS medium containing 1 mg/mL of LA. The CLA production significantly increased with increasing LA concentration, from 1 to 4 mg/mL, but the conversion of LA to CLA gradually decreased. The CLA production capability of B. breve, and its tolerance, improved significantly with LA-adaptation. The addition of LA (1 mg/mL) into the culture broth after 24 h of cultivation in a 100-mL media bottle was most effective at promoting CLA production. In a 2.5-L stirred-tank bioreactor, the observed conversion and productivity of $56.6\%\;and\;35.4{\mu}gmL^{-1}h^{-1}$, respectively, by LA-adapted B. breve were approximately 6.6 and 9.8 times higher than those of LA-unadapted B. breve.

Development of a plasma gun for long lifetime (장수명 플라즈마 건의 개발)

  • Choi, Young-Wook
    • Proceedings of the KIEE Conference
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    • 2007.11a
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    • pp.192-193
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    • 2007
  • A hollow cathode which has extremely stable discharge characteristic has been developed. This is composed of the two separated lanthanum hexaboride ($LaB_6$) of a disk type in the tube as the electron emitters. The way of design is of great advantage to extend the surface discharge area of the $LaB_6$, which is also useful for optimal fixing of the $LaB_6$. The hollow cathode is capable of producing 30 kW (100 V, 300 A) of power continuously.

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Development of a Plasma Gun System for Ion Plating with Long Lifetime (이온 플레이팅용 장수명 플라즈마 건 장치의 개발)

  • Choi, Young-Wook
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.1
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    • pp.78-81
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    • 2008
  • A hollow cathode which has extremely stable discharge characteristic has been developed. This is composed of the two separated lanthanum hexaboride(LaB6) of a disk type in the tube as the electron emitters. The way of design is of great advantage to extend the surface discharge area of the LaB6, which is also useful for optimal fixing of the LaB6. The hollow cathode is capable of producing 30 kW(100 V, 300 A) of power continuously. Because the generated plasma beam with the high temperature(above $3000^{\circ}C$) from the hollow cathode passes through the center hole of the two intermediate electrodes, it is designed with the high temperature material of the tungsten and the suitable structure of the water cooling. The combinations of the hollow cathode and the two intermediate electrodes are practically useful for the ion plating plasma beam source.

Assessment of Radiographic Left Atrial Dimension in Maltese Dogs with ACVIM Stage B Myxomatous Mitral Valve Disease

  • Song-In Lee;Han-Joon Lee;Joong-Hyun Song;Kun-Ho Song
    • Journal of Veterinary Clinics
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    • v.39 no.6
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    • pp.287-293
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    • 2022
  • Radiographic left atrial dimension (RLAD) is a useful measurement to assess left atrial enlargement in dogs. There are studies on the use of RLAD on various breeds of dogs, but no study on a specific breed with myxomatous mitral valve disease (MMVD). This study was conducted to compare RLAD measurements in Maltese dogs with MMVD ACVIM stage B1 and B2, and also to investigate the correlation of RLAD with the LA:Ao ratio. A total of 29 Maltese dogs were the subjects of this study. Each dog was diagnosed with MMVD ACVIM stage B1 or B2 based on physical examination, thoracic radiography, and echocardiography. The vertebral heart size (VHS), RLAD, LVIDDn, and LA:Ao ratio were measured and compared to evaluate the differences. There were significant differences in the RLAD, LVIDDn, and LA:Ao ratio between dogs with MMVD ACVIM stage B1 and those with stage B2. There was a significant correlation between the LA:Ao ratio and both the RLAD and VHS measurements, but the correlation coefficient was higher for RLAD. The RLAD scores exhibited a significant difference between dogs with ACVIM Stage B1 and with those with B2, and these scores had a higher correlation with the LA:Ao ratio measured by echocardiography than with VHS.

Electronic and Magnetic Properties of Rare-earth Transition Metal Compound : $LaCo_{13}$ ($LaCo_{13}$ 희토류-전이금속 화합물의 전자기적 물성연구)

  • 민병일;손진군
    • Journal of the Korean Magnetics Society
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    • v.3 no.1
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    • pp.1-6
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    • 1993
  • Electronic and magnetic proper tis of the rare-earth transition metal compound, $LaCo_{13}$, are investigated by performing self-consistent local density functional LMTO (linearized muffin-tin orbital) band structure calculations for both paramagnetic and ferromagnetic phases of $LaCo_{13}$. The calculated magnetic moments for the two types of Co atoms, Co I and Co II, are 1.34 and $1.65{\mu}_{B}$, respectively. The average magnetic moment of Co atoms in the ferromagnetic phase of $LaCo_{13}$ is estimated to be $1.60{\mu}_{B}$, which is in fairly good agreement with the experimental values, $1.56~1.68{\mu}_{B}$.

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Preparation and Characterization of Ordered Perovskite (CaLa) (MgMo) $_6$

  • Choy, Jin-Ho;Hong, Seung-Tae;Suh, Hyeong-Mi
    • Bulletin of the Korean Chemical Society
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    • v.9 no.6
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    • pp.345-349
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    • 1988
  • The polycrystalline powder of (CaLa) (MgMo)$O_6$ has been prepared at $1350^{\circ}C$ in $H_2/H_2O$ and $N_2$ flowing atmosphere. The powder X-ray diffraction pattern indicates that (CaLa) (MgMo)$O_6$ has a monoclinic perovskite structure with the lattice constants $a_0=b_0=7.901(1){\AA}$, $c =7.875(1){\AA}\;and\;{\gamma}=89^{\circ}$16'(1'), which can be reduced to orthorhombic unit cell, a = 5.551(1) ${\AA}$, b = 5.622(1) ${\AA}$ and c = 7.875(1) ${\AA}$. The infrared spectrum shows two strong absorption bands with their maxima at 590($ν_3$) and 380($ν_4$) cm, which are attributed to $2T_{1u}$ modes indicating the existence of highly charged molybdenum octahedron $MoO_6$ in the crystal lattice. According to the magnetic susceptibility measurement, the compound follows the Curie-Weiss law below room temperature with the effective magnetic moment 1.83(1)$_{{\mu}B}$, which is well consistent with that of spin only value (1.73 $_{\mu}_B$) for $Mo^{5+}$ with $4d^1$-electronic configuration within the limit of experimental error. From the thermogravimetric analysis, it has been confirmed that (CaLa) (MgMo)$O_6$ decomposes gradually into $CaMoO_4,\;MoO_3,\;MgO,\;La_2O_3$ and unidentified phases due to the oxidation of $Mo^{5+}$ to $Mo^{6+}$.

Structural Characterization of Incommensurate Misfit Layer Compound $(LaS)_xVS_2(x\approx 1.18)$ (비정합 결정구조를 갖는 $(LaS)_xVS_2(x\approx 1.18)$의 결정구조적 특성연구)

  • 조남웅;유광수;정형진
    • Journal of the Korean Ceramic Society
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    • v.31 no.6
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    • pp.617-622
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    • 1994
  • Single crystals of misfit layered (LaS)xVS2(x 1.18) were grown using LaCl3(or I2) as a mineralizer (or transport agent) for the single crystal X-ray diffraction analysis. Procession photographs of (LaS)xVS2(x 1.18) were analyzed as the stacking structure of two kinds of LaS-and VS2-subcell. The result shows that two sublattices have common periodicities along the a*-and c*-axes, respectively, but not along the b*-axis. Sublattice dimensions of LaS and VS2 layers along b-axis were 5.67$\AA$ and 3.42$\AA$, respectively. Their ratio was 1.657 which is very close to 5/3.

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Cytotoxicity on Cancer cells of the Extract of Sophora flavescens Ait. (고삼 추출물의 암세포에 대한 세포독성)

  • Lee, Hyun-Ok;Chun, Ju-Yeon;Lee, Ji-Youn;Kim, Chang-Hee
    • Journal of dental hygiene science
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    • v.2 no.1
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    • pp.15-19
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    • 2002
  • In this study, we investigated the cytotoxicity of ethyl acetate subfraction of Sophora flavescens Ait.(EASS) on cancer cells using MTT quantitative analysis. The EASS was cytotoxicity from the concentration of 6.25 g/ml to KB, B16, HeLa, and MCF-7 cancer cells and the cytotoxicity was significant, (p < 005) increased as the concentrations of EASS were increased, (12.5, 25, 50, 100 g/ml). The IC for KB, B16, HeLa, and MCF-7 were 56.58, 65.43, 83.95, and 106.65 g/ml, respectively. Conclusively, the EASS inhabited the growth of cancer cells and the order of potency of cytotoxicity was KB > B16 > HeLa > MCF-7.

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Differential Effect of n6 and n3 Polyunsaturated Fatty Acids on Plasma Lipids in Rats Fed Low and High Fat Diets (식이지방 수준에 따라 n6 와 n3 계 불포화지방산이 혈장 지질수준에 미치는 영향에 관한 비교연구)

  • Nam, Jung-He;Park, Hyun-Suh
    • Journal of Nutrition and Health
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    • v.24 no.4
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    • pp.314-325
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    • 1991
  • To compare the hypolipidemic effects of n6 and n3 PUFA at different fat levels, male Sprague Dawley rats were fed either low fat (LF, 10% Cal) or high fat (HF, 40% Cal) diet which was different only in fatty acid composition for 6 weeks. Dietary fats were beef tallow, corn oil, perilla oil, and fish oil concentrate as a source of saturated fatty acid, n6 linoleic acid(LA). n3 ${\alpha}-linolenic$ acid(LL) and n3 eicosapentaenoic acid(EPA)+docosahexaenoic acid(DHA), respectively. VLDL fraction was separated by ultracentrifugation and chemical composition was determined by thin layer chromatography. Plasma cholesterol level was increased by n6 LA but decreased by n3 LL and n3 EPA in LF and HF diets, and the hypocholesterolemic effect of n3 EPA was most significant in HF diet. HDL-Chol level was raised by n6 LA in LF and HF diets, but significantly reduced by n3 EPA in HF. Plasma TG level was reduced by n6 LA n3 LL and EPA in LF and HF with the reduction of lipogenic enzyme activity only by n3 PUFAs. The proportion of TG in VLDL fraction was significantly lowered by n3 EPA in LF and HF. The proportion of apo-B in VLDL fraction was not changed in LF, but was significantly decreased in HF by n3 EPA. Therefore, the hypotriglyceridemic effect of n3 PUFA could be from the reduced lipogenesis in liver and resulted in the depressed secretion of TG as VLDL in LF and HF with significant lower production of apoB in HF diet.

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Microwave dielectric properties of $La_2O_3-CaO-B_2O_3$ glass-added alumina ($La_2O_3-CaO-B_2O_3$계 유리 첨가 알루미나 복합체의 유전특성)

  • Lim, Dong-Ha;Kim, Hyun-Beom;Shin, Hyun-Ho
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.06a
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    • pp.323-323
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    • 2007
  • Influence of $La_2O_3$ addition to $CaO-B_2O_3$-based glass on the water leaching resistance of the glass was first investigated. The optimized $La_2O_3-CaO-B_2O_3$(LCB) glass was ball milled for varying time, followed by mixing with $Al_2O_3$ crystalline phase to form $Al_2O_3$-LCB glass composites at $875^{\circ}C$ for 1h. Microwave dielectric properties of the composites were investigated as a function of the ball milling time of the LCB glass. Dielectric constant and quality factor of the composites were 6.31 and 13856 GHz, respectively, when the LCB glass was ball milled for 2h prior to mixing with $Al_2O_3$.

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