• 한국식품영양과학회지
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• 제37권6호
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• pp.752-760
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• 2008

One liter stirred-tank batch reactor에서 기질들의 부피 비율을 1:2:7(fully hydrogenated soybean oil : SL-olive+CLA : palm oil)하고 RM IM lipase를 사용하여 CLA를 함유한 재구성 지질을 합성하였다. 합성된 재구성지질은 총 CLA를 7.6 area% 함유하였고, 주요 지방산 조성은 oleic acid (38.1 area%), palmitic acid(33.1 area%), stearic acid(12.2area%) 및 linoleic acid(7.3 area%)로 분석되었으며 트랜스지방산은 분석한계 미만(0.1 area%)으로 검출되었다. Reversed-phase(RP) HPLC 분석 결과, 재구성 지질의 TAG 형태는 PN=44(1.52 area%), PN=46(21.79 area%), PN=48(53.71 area%) 및 PN=50(11.1 area%)의 범위로 나타내었다. 합성된 지질의 토코페롤 함량을 분석한 결과는 ${\alpha}$, ${\gamma}$-토코페롤이 각각 4.7, 1.0 mg/100 g로 반응기질보다 감소하였고, 이의 산가, 비누화가, 요오드가의 측정 결과는 각각 0.4, 173.9, 59.0이었다. 재구성 지질의 융점은 세 개의 피크를 보이며 각각 8.7, 25.3 및 $40.9^{\circ}C$으로 나타났고 결정화점은 각각 0.7, $18.2^{\circ}C$로 분석되었다. 또한 고체지 함량은 31.8%($25^{\circ}C$), 22.3%($30^{\circ}C$), 13.9%($35^{\circ}C$)를 나타내어 상업적인 쇼트닝과 유사한 물성을 보였다. 재구성 지질의 녹는점은 $39.8^{\circ}C$로 측정되었고, hardness value는 63.8 g로 분석되었다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 추계학술발표강연 및 논문개요집
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• pp.138-138
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• 2003

Low temperature co-fired ceramic (LTCC) technology offers significant benefits over the other established packaging technologies for high density, high microwave frequency, and fast signal application. Most conventional electroceraramics do not meet the basic requirements in respect of sinterability for LTCC technology. Attention is, therefore, focused on the role of glasses because of the capability they supply with lower sintering temperatures. In this study, commercial ceramic (MBRT-90) in the system BaO-N $d_2$ $O_3$-Ti $O_2$ (BNT: 40 ~ 80 wt%) and L $a_2$ $O_3$- $B_2$ $O_3$-Ti $O_2$ glass (LBT;60 ~ 20 wt%) were prepared. These glass/ceramic composites were evaluated for sintering behavior, phase evaluation, densities, interface reaction, crystallinity, microstructure and microwave dielectric properties. It was found that the addition LBT glass frits significantly lowered the sintering temperature to below 90$0^{\circ}C$ and as temperature increased (750~90$0^{\circ}C$) densification developed dynamically which was meant to be as over 95% of relative density. It is supposed that in the microstructure, the grain size was increased accompanying with the formation of different phases such as LaB $O_3$ and Ti $O_2$ under the condition of increasing sintering temperature. The sintered bodies represented applicable dielectric properties, namely 20 ~ 40 for $\varepsilon_{{\gamma}}$, ~ 10000 GHz for Q* $f_{0}$ and 10~80 ppm/$^{\circ}C$ for $\tau$$_{f}$. The results suggest that the composite is one of feasible candidates for the microwave use in LTCC technology.y.e use in LTCC technology.y.

• 한국세라믹학회지
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• 제33권1호
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• pp.1-6
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• 1996

A single phase Ba2(Ti8,472Zr0.528)O20 was prepared by the oxalate method from aqueous solution of BaCl2 TiCl4 and ZrOCl2. The structure ananlysis has been carried out by Rietveld analysis method at room temperature. Powder X-ray data of Ba2(Ti8,472Zr0.528)O20 was indexed with the triclinic lattice(a=7.4587 $\AA$ b=14.0672 $\AA$, c=13.3327 $\AA$, $\alpha$=89.87, $\beta$=79.45 ${\gamma}$=84.46) The R (Residual) values of structure refinement were in a range between 10.00 and 8.00 This analysis proved that the added Zr occupied Ti sites in th structure of Ba2Ti9O20. Ba2(Ti8,472Zr0.528)O20 has excellent dielectric properties(dielectric constant K=40.49 at 5.42 GHz Q=4621) so that it can be used as good microwave dielectric materials.

• 한국전자파학회논문지
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• 제15권1호
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• pp.44-50
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• 2004

본 논문에서는 FR4(h= 1.6 mm, $\varepsilon_{{\gamma}}$/=4.6) substrate 상에서 2 GHz 대역의 이중 평형 혼합기를 구현하였다. 일반적으로, DBM(Doubly Balanced Mixer)는 2개의 발룬과 쿼드 다이오드로 구성된다. 발룬을 위해, microstrip과 CPS(Coplanar Strip)을 이용한 새로운 발룬 회로가 제안되고, 설계되어졌다. 제안된 발룬의 측정 결과, 1.5 GHz에서 2.5 GHz내에서 위상의 불평형 정도가 180$^{\circ}$$\pm$ $1.5^{\circ}$이내였으며, 진폭의 불평형 정도가 $\pm$ 0.2 ㏈ 이내였다. 발룬을 사용한 DBM이 성공적으로 구현되었으며, 동작 대역 내에서 up/down 변환기로써 변환 손실은 약 6 ㏈ 정도를 보였다. 더 많은 연구를 통해, backside via를 포함하는 프로세스가 있는 MMIC(Monolithic Microwave Integrated Circuit) DBM에 적용 가능할 것이다.d Circuit) DBM에 적용 가능할 것이다.

• 생명과학회지
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• 제21권9호
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• pp.1346-1353
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• 2011

산두근(Sophora tonkinensis Gapnep)은 예로부터 동양지역에서 전통적인 약용식물로 사용되어 왔다. 본 연구에서는 3T3-L1 지방전구세포의 성숙지방세포로의 분화와 세포 내 지방생성에 대한 산두근 메탄올 추출물(STME)의 효과와 메커니즘에 대해 조사하였다. STME를 0-200 ${\mu}g$/ml의 농도로 처리한 다음, Oil Red O 염색으로 세포 내축적되는 지방구와 지질의 양을 측정한 결과 농도의존적으로 크게 감소됨을 확인하였으며 3T3-L1 지방전구세포의 분화와 관련된 단백질의 발현의 변화를 조사하였다. 지방세포의 특이적 marker인 peroxisome proliferator-activated receptor ${\gamma}$ (PPAR${\gamma}$), cytidine-cytidine-adenosine-adenosine-thymine (CCAAT)/enhancer-binding proteins ${\alpha}$, ${\beta}$ (C/EBP${\alpha}$, C/EBP${\beta}$) 그리고 sterol regulatory element binding protein (SREBP)의 발현이 STME를 처리하였을 때 현저하게 저해됨을 확인하였다. 세포주기의 변화를 분석한 결과 STME는 지방세포 분화초기 단계인 mitotic clonal expansion 단계에서 G1기로 세포주기를 정지시켰다. 더불어 G1 arrest와 관련된 단백질의 변화를 조사 한 결과, 3T3-L1 세포에 STME를 처리하였을 때 p21의 발현량이 확연하게 증가하였으며, Cdk2, E2F-1 그리고 phosphor-Rb의 발현량은 농도의존적으로 감소하였다. 이러한 결과들에 의하여 STME은 메탄올 추출물임에도 불구하고 3T3-L1 지방전구세포가 성숙지방세포로 분화할 때 G1 arrest를 통하여 지방세포 분화를 억제하며 관련 유전자의 발현 억제도 확연하게 확인할 수 있었으며, 이러한 결과는 항 비만 천연물 소재 탐구의 기초자료로 유용하게 쓰일 것으로 사료된다.

• 한국세라믹학회지
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• 제50권2호
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• pp.108-115
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• 2013

Oxide coatings were prepared on Al-1050 substrates by an environment-friendly plasma electrolytic oxidation (PEO) process using an electrolytic solution of $Na_2SiO_3$ (8 g/L) and NaOH (3 g/L). The effects of three different duty cycles (20%, 40%, and 60%) and frequencies (50 Hz, 200 Hz, and 800 Hz) on the structure and micro-hardness of the oxide coatings were investigated. XRD analysis revealed that the oxides were mainly composed of ${\alpha}-Al_2O_3$, ${\gamma}-Al_2O_3$, and mullite. The proportion of each crystalline phase depended on various electrical parameters, such as duty cycle and frequency. SEM images indicated that the oxide coatings formed at a 60% duty cycle exhibited relatively coarser surfaces with larger pore sizes and sintering particles. However, the oxides prepared at a 20% duty cycle showed relatively smooth surfaces. The PEO treatment also resulted in a strong adhesion between the oxide coating and the substrate. The oxide coatings were found to improve the micro-hardness with the increase of duty cycle. The structural and physical properties of the oxide coatings were affected by the duty cycles.

• BMB Reports
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• 제29권5호
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• pp.429-435
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• 1996

To investigate the structure-antagonistic relationship of the cyclohexapeptide L-659,877, a selective NK-2 tachykinin receptor antagonist, seven analogues were chemically synthesized by a solid phase method. The agonistic and antagonistic activities of the analogues were evaluated by contraction assay using the smooth muscle of guinea pig trachea (GPT) containing the NK-2 receptor. It was shown that the aromatic ring of Phe at position 3 and the sulfur group of Met at position 6 in L-659,877 were essential for binding to the NK-2 receptor. Decrease in antagonistic activity of L-659,877 caused by substituting Leu for Nle at position 5 indicates that the ${\gamma}$ methyl group and side chain length of Leu plays an important role in its antagonistic action. Although the activity was slightly lower than L-659,877, cyclo $[{\beta}Ala^{8}]NKA(4-10)$ (analogue 1) showed potential antagonistic activity for the NK-2 receptor. It was confirmed that the expansion of the ring in L-659,877 by substitution of ${\beta}Ala$ for Gly at position 4 stabilized its conformation monitored by CD spectra. The results suggest that analogue 1 can be used as a new leader compound to design a more powerful, selective, and stable NK-2 receptor antagonist.

• Bulletin of the Korean Chemical Society
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• 제26권7호
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• pp.1065-1070
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• 2005

$[Mn_{12}O_{12}(O_2CPh-4-SMe)_{16}(H_2O)_4]{\cdot}7CH_2Cl_2$ (1), a new single-molecule magnet complex has been successfully synthesized by substitution of acetate ligand of Mn12ac with 4-(methylthio)benzoic acid. Complex 1 crystallizes into triclinic P$\overline{1}$ with a = 18.321(3) $\AA$, b = 19.011(3) $\AA$, c = 27.230(4) $\AA$, $\alpha$ = 86.973(3)$^{\circ}$, $\beta$ = 76.919(3)$^{\circ}$, $\gamma$ = 87.613(3)$^{\circ}$, and Z = 2. In complex 1, one Mn(III) ion has an abnormal Jahn-Teller elongation axis oriented at an oxide ion. Complex 1 has two out-of-phase ac susceptibility peaks in the 2-4 K and 4-7 K regions. Effective anisotropy energy barrier and pre-exponential factor are $U_{eff}$ = 45.95 K, 1/$\tau$0 = 8.6 ${\times}\;10^9s^{-1}\;for\;{\chi}_M$'' peaks in the lower temperature region and $U_{eff}$ = 59.45 K, 1/$\tau_0$ = 2.2 ${\times}\;10^8\;s^{-1}$ for $\chi_M$'' peaks in the higher temperature region. The parameters of S = 10, g = 1.87, D = -0.40 $cm^{-1}$, and E = 0.00034 $cm^{-1}$ were obtained from the M/N${\mu}_B$ vs. H/T plot of complex 1.

• 동의생리병리학회지
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• 제21권6호
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• pp.1437-1449
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• 2007

In this study, the effect of extract of Corydalis yanhusuo (ECT) used in Oriental medicine therapy was investigated on the cell growth and apoptosis of HepG2 human hepatoma cells. It was found that ECT could inhibit the cell growth effectively in a dose-dependent manner, which was associated with morphological change and apoptotic cell death such as formation of apoptotic bodies, DNA fragmentation and increased populations of apoptotic-sub G1 phase. And we observed the effects of ECT on loss of mitochondrial membrane potential (MMP), using the JC-1 probe by DNA flow cytometric analysis. Apoptosis of HepG2 cells by ECT was associated with a down-regulation of anti apoptotic Bcl-2 expression, inhibitor of apoptosis proteins (IAPs) expression and proteolytic activation of caspase-3 and caspase-9. However, ECT did not affect the pro-apoptotic Bax expression and activity of caspase-8. ECT treatment also concomitant degradation and /or inhibition of poly (ADP-ribose) polymerase (PARP), phospholipase C-1 ($PLC{\gamma}1$). Furthermore, ECT treatment caused a dose-dependent inhibition of iNOS and cyclooxygenase-2 (Cox-2). Additionally ECT have been implicated in the regulation of telomerase expression. ECT treatment induced the down-regulation of telomerase reverse transcriptase mRNA (hTERT) expression of HepG2 cells. Taken together, these findings suggest that ECT may be a potential chemotherapeutic agent for the control of HepG2 human hepatoma cells.

• 한국분말재료학회지
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• 제15권1호
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• pp.23-30
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• 2008

Ni-20Cr-20Fe-5Nb alloy with or without $Y_2O_3$ was manufactured by mechanical alloying process and consolidated by spark plasma sintering (SPS). The grain size of the alloy with $Y_2O_3$ was smaller than that of alloy without $Y_2O_3$ which results from the effect of $Y_2O_3$ suppressing grain growth. The tensile strength at room temperature was increased by the addition of $Y_2O_3$ but decreased abruptly at temperature above $600^{\circ}C$. It seems to result from the change of deformation mechanism due to fine grain size, that is, grain boundary sliding is predominant at above $600^{\circ}C$ while internal dislocation movement is predominant at below $600^{\circ}C$. After conventional heat treatment process of solution treatment and aging, a small amount of ${\delta}(Ni_3Nb)$ phase was formed in Ni-20Cr-20Fe-5Nb alloy while a large amount of ${\gamma}"(Ni_3Nb)$ was formed in Inconel 718 in the previous report. This is due to exhaustion of Nb content by the formation of NbC during consolidation.