• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 추계학술대회 논문집
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• pp.233-244
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• 2004

ZnO epilayer were synthesized by the pulesd laser deposition(PLD) process on $Al_2O_3$ substrate after irradiating the surface of the ZnO sintered pellet by the ArF(193nm) excimer laser. The epilayers of ZnO were achieved on sapphire ($Al_2O_3$)substrate at a temperature of $400^{\circ}C$. The crystalline structure of epilayer was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of ZnO epilayer measured with Hall effect by van der Pauw method are $8.27{\times}10^{16}\;cm^{-3}$ and $299\;{\textrm}cm^2/V.s$ at 293K. respectively. The temperature dependence of the energy band gap of the ZnO obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)\;=\;3.3973\;eV\;-\;(2.69{\times}10^{-4}\;eV/K)T^2/(T+463K)$. After the as-grown ZnO epilayer was annealed in Zn atmospheres, oxygen and vaccum the origin of point defects of ZnO atmospheres has been investigated by the photoluminescence(PL) at 10K. The native defects of $V_{zn},\;Vo,\;Zn_{int},\;and\;O_{int}$ obtained by PL measurements were classified as a donors or acceptors type. In addition, we concluded that the heat-treatment in the oxygen atmosphere converted ZnO thin films to an optical p-type. Also, we confirmed that vacuum in $ZnO/Al_2O_3$ did not form the native defects because vacuum in ZnO thin films existed in the form of stable bonds.

• Asian-Australasian Journal of Animal Sciences
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• 제17권1호
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• pp.27-32
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• 2004

Using MLV (murine leukemia virus)-based retrovirus vectors encapsidated with VSV-G (vesicular stomatitis virus G glycoprotein), we tried to make transgenic chickens carrying the transferred genes in their chromosomes. Twenty one days after virus injection beneath the blastoderms of unincubated chicken embryos (stage Ⅹ, at laying), DNA isolated from the hatched chicks were analyzed by PCR with two sets of primers specific for EGFP (enhanced green fluorescence protein) gene or $Neo^R$ (E. coli neomycin resistant) gene. Among sixty-seven embryos injected with retrovirus, four of them were identified to carry the EGFP genes in their genomes. Remarkably, one transgenic chick showed presence of the retrovirus vector sequences in all organs differentiated from one of endoderm, mesoderm, and ectoderm. Expression of EGFP gene was not detected, however, the stable germ line transmission of transgene was verified in spermatozoa from the founder chicken and 50% of $F_1$ progenies.

• Asian Pacific Journal of Cancer Prevention
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• 제16권3호
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• pp.1277-1280
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• 2015

Aim: To report epidemiologic and anatomoclinical transitions of inflammatory breast cancer (IBC) in Tunisia. Materials and Methods: Data including clinico-pathological data for 208 cases of T4d or PEV 3 non-metastatic breast cancer diagnosed between 2005 and 2010 were collected from patient records. Chi2 and Z tests were used to compare variables with two Tunisian historical series and a series about Arab-American patients. Results: Thirty three percent of our patients had their first child before 23 years of age and 56% had their menarche before 12 years, 75% never receiving oral contraception. Obesity was observed in 42% of women and IBC occurred during pregnancy in 13% of cases. Tumor grade was II-III in 90% of cases, HR was negative in 52%, HER2 was over expressed in 31% and invasion of more than 3 axillary nodes occurred in 18% of patients. We observed a pCR rate of 19% after neoadjuvant treatment (anthracyline-taxane used in 79%, trastuzumab in 27% ). Compared to historical Tunisian series (since 1996), IBC epidemiology remained stable in terms of median age, menopausal status and obesity. However we observed a significant decrease in median clinical tumor size and number of positive axillary lymph nodes. Comparison to IBC in Arab-Americans showed a significant difference in terms of median age, menopausal status, positivity of hormonal receptors and educational level. Conclusions: Our assessment of epidemiologic transition showed a reduction of clinco-pathological stage of IBC, keeping the same characteristics as compared to Tunisian historical series over a period of 14 years. Features seem to be different in Arab-American patients, probably related to migration, "occidentalization" of life style and improvement in socio-economic level.

• Journal of Microbiology and Biotechnology
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• 제15권1호
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• pp.155-160
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• 2005

Abstract A direct approach was used to retrieve active lipases from Paenibacillus polymyxa genome databases. Twelve putative lipase genes were tested using a typical lipase sequence rule built on the basis of a consensus sequence of a catalytic triad and oxyanion hole. Among them, six genes satisfied the sequence rule and had similarity (about 25%) with known bacterial lipases. To obtain the six lipase proteins, lipase genes were expressed in E. coli cells and lipolytic activities were measured by using tributyrin plate and pnitrophenyl caproate. One of them, contig 160-26, was expressed as a soluble and active form in E. coli cell. After purifying on Ni-NTA column, its detailed biochemical properties were characterized. It had a maximum hydrolytic activity at $30^{\circ}C$ and pH 7- 8, and was stable up to $40^{\circ}C$ and in the range of pH 5- 8. It most rapidly hydrolyzed pNPC$_6$ among various PNPesters. The other contigs were expressed more or less as soluble forms, although no lipolytic activities were detected. As they have many conserved regions with lipase 160-26 as well as other bacterial lipases throughout their equence, they are suggested as true lipase genes.

• 한국전기전자재료학회논문지
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• 제17권5호
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• pp.467-475
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• 2004

ZnO epilayer were synthesized by the pulsed laser deposition(PLD) process on $Al_2$ $O_3$substrate after irradiating the surface of the ZnO sintered pellet by the ArF(193 nm) excimer laser. The epilayers of ZnO were achieved on sapphire(A $l_2$ $O_3$) substrate at a temperature of 400 $^{\circ}C$. The crystalline structure of epilayer was investigated by the photoluminescence and double crystal X-ray diffraction(DCXD). The carrier density and mobility of ZnO epilayer measured with Hall effect by van der Pauw method are 8.27${\times}$$10^{16}$$cm^{-3}$ and 299 $\textrm{cm}^2$/Vㆍs at 293 K, respectively. The temperature dependence of the energy band gap of the ZnO obtained from the absorption spectra was well described by the Varshni's relation, $E_{g}$(T)= 3.3973 eV - (2.69 ${\times}$ 10$_{-4}$ eV/K) $T^2$(T＋463k). After the as-grown ZnO epilayer was annealed in Zn atmospheres, oxygen and vaccum the origin of point defects of ZnO atmospheres has been investigated by the photoluminescence(PL) at 10 K. The native defects of $V_{Zn}$ , $V_{o}$ , Z $n_{int}$, and $O_{int}$ obtained by PL measurements were classified as a donors or accepters type. In addition, we concluded that the heat-treatment in the oxygen atmosphere converted ZnO thin films to an optical p-type. Also, we confirmed that vacuum in ZnO/A $l_2$ $O_3$did not form the native defects because vacuum in ZnO thin films existed in the form of stable bonds.s.s.s.

• 전기화학회지
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• 제5권2호
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• pp.62-67
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• 2002

용융탄산염 연료전지의 성능 저하와 수명 감소의 원인이 되는 부식 현상을 규명하고자 분리판 재료로 가장 널리 사용되고 있는 AISI-type 316L stainless steel을 대상으로 62Li/38K계 용융탄산염 내에서의 부식 실험을 수행하였다. 부식의 형태 및 속도는 환경에 의하여 다양하게 변화하게 되며, 용융탄산염 내에서 AISI-type 316L stainless steel의 부식 속도는 부식 반응에 의하여 형성되는 부동태 산화막의 안정성에 의하여 크게 영향을 받는다. 전기화학적 분극 거동을 분석한 결과 용융탄산염 연료전지의 anode가슨 분위기에서는 안정한 부동태 산화막이 형성되지 않았다. 순환 전압전류법과 정전위법을 이용한 부식 생성물의 X-ray분석을 통하여 특정한 전기화학적 전위 영역에서 반응기구와의 인과관계를 규명하고 다양한 형태의 부식 반응들을 분리해 내었다.

• 한국재료학회지
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• 제7권1호
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• pp.33-39
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• 1997

ECR PECVD법에 의해 $Pt/Ti/SiO_{2}/Si$ 다층 기판 위에 $480^{\circ}C$에서 순수한 페로브스카이트상의 PLT박막을 증착하였다. PLT 박막 증착전 ECR산소 플라즈마내에서의 $Pb(DPM)_{2}$ pre-flowing처리는 $Pb(DPM)_{2}$의 공급을 안정화시켜주며 박막증착초기에 Pb성분이 풍부한 분위기를 조성해 줌으로써 페로브스카이트 핵생성을 용이하게 하여 PLT박막 특성을 향상시켰다. Ti-source 유입량을 변화시킬 때 PLT박막의 증착특성, 조성, 결정상 그리고 전기적 특성을 관찰하였다. PLT박막은(100)으로 우선 배향되었으며 화학양론비가 잘 맞는 경우 높은 페로브스카이트 X-선 회절강도와 높은 유전율을 나타내었다.

• Mass Spectrometry Letters
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• 제3권4호
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• pp.93-100
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• 2012

Cellular processes such as proliferation, differentiation, and adaptation to environmental changes are regulated by protein phosphorylation. In order to enhance the understanding of molecular dynamics for biological process in detail, it is necessary to develop sensitive and comprehensive analytical methods for the determination of protein phosphorylation. Neural stem cells hold great promise for neural repair following an injury or disease. In this study, we made differentiated oligodendrocytes from human neural stem cells using over-expression of olig2 gene. We confirmed using quantitative phosphoproteome analysis approach that combines stable isotope labeling by amino acids in cell culture (SILAC) and $TiO_2$ micro-column for phosphopeptide enrichment with $MS^2$ and $MS^3$ mass spectrometry. We detected 275 phosphopeptides which were modulated at least 2-fold between human neural stem cells and oligodendrocytes. Among them, 23 phosphoproteins were up-regulated in oligodendrocytes and 79 phosphoproteins were up-regulated in F3 cells.

• 한국초지조사료학회지
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• 제14권4호
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• pp.288-294
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• 1994

Birdsfoot trefoil(MO-20)과 tetraploid narrowleaf trefoil(PI302921)및 이들 종간 잡종의 유식물 확력을 건물축적량 광합성율 생장분석 등을 통하여 비교검토하였다. 일반적으로 종간 잡종의 표현형은 그 들 부모의 중간 특성을 나타내었으며, 암호흡, 광합성 및 휴식물생육은 이 들 모계 계통인 MO-20 birdsfoot trefoil과 유사하였다. 중간잡종은 birdsfoot trefoil 보다 빨리 자랐으나 통계적인 유의성은 없었다. 또한 교잡종은 narrowleaf trefoil보다 유식물 활력이 더 우수하였는데 그것은 낮은 암호흡율과 높은 상대성장율에 기인되었다. 앞으로 birdsfoot trefoil의 유식물 활력의 유전적인 개량은 새로운 분야로서 개량의 여지가 많음을 보여 주었다.

• 생명과학회지
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• 제11권5호
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• pp.457-463
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• 2001

Staphylococcus xylosus SC-22으로 생성된 lipase을 분리. 정제하여 특성을 조사하였다. Staphylococcus xylosus SC-22의 배양액을 ammonium sulfate (30~80%), Sepadex G-100 및 DEAE-Sephacel chromatography의 정제과정을 거친 결과, specific activity가 756.6 units/mg protein으로 19.3배 정제도었으며 수율은 17.2%로 나타났다. 정제효소의 분자랴은 47kDa, 정제된 효소의 특성은 최적온도은 4$0^{\circ}C$, 최적 pH는 8.0이었으며, pH 안정성 범위는 pH 6.0~10.0부근에서 비교적 안정하였다. Alkaline lipase의 활성은 C $u^{2+}$와 P $b^{2+}$에 의해 완전히 저해되었으며, F $e^{3+}$ 에 의해 50% 효소활성이 저해되었으나, $Ca^{2+}$, $Mg^{2+}$, $Na^{+}$에 의해 저해를 받지 않았다.