• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.10a
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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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• v.17 no.1
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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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• v.16 no.3
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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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• v.15 no.1
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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.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.5
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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.

• Journal of the Korean Electrochemical Society
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• v.5 no.2
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• pp.62-67
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• 2002

The corrosion of the metallic cell components is blown to be one of the major reason f3r the performance degradation and subsequently the life-time limitation of the MCFC. To elucidate the corrosion phenomena, a corrosion study with the AISI-type 316L stainless steel, the most widely used separator material, in 621Li/38K carbonate eutectic melt was carried out. Corrosion phenomena in an MCFC were observed to differ from one location to another due to different environmental condition. The stability of passive film was found to be responsible fur the variations in corrosion phenomena. According to the potentiodynamic analysis, the passive film formed in anode-gas environment was less stable than in cathode-gas environment. The potentiostatic method combined with XRD analysis in addition to the cyclicvoltammetry was conducted to get an insight on variety corrosion reaction of AISI-type 316L stainless steel in a carbonate melt.

• Korean Journal of Materials Research
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• v.7 no.1
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• pp.33-39
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• 1997

Single phase pero~~skite lead lanthanum titanate thin films were fabricated on $Pt/Ti/SiO_2/Si$ substrates at the temperature of $480^{\circ}C$ by electron cyclotron resonance plasma-enhanced chemical vapor deposition (ECR PECVD) using metal organic sources $Pb(DPM)_2$ pre-flowing treatment in ECIi oxygen plasma before fabricating PLT films 11romote the perovskite nucleation due to stable supplying of the $Pb(DPM)_2$ and providing the F'h-rich atmosphere in the early stage of deposition. $Pb(DPM)_2$ pie-flonring treatment enhanced the properties of PLT films. The charactcristics of the PLT filrris were investigated as a tunction of the flow rate of Ti-source. The PL'i' films were grown in a perovskite structure tvith (100) preferred orientation. The high X-ray diffraction intensity and dielectric constant were obtained from the stoichiometric perovskite $(Pb,La)TiO_3$.

• Mass Spectrometry Letters
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• v.3 no.4
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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.

• Journal of The Korean Society of Grassland and Forage Science
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• v.14 no.4
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• pp.288-294
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• 1994

Seedling vigor of introgressive hybrids between birdsfoot refoil 'MO-20"(Lotus corniculatus) used as the maternal parent and tetraploid(2n=4x=24)accession PI302921 narrowleaf trefoil(Lotus corniculatus L.), and parents were compared in terms of dry matter accumulation , net photosynthetic rate, dark respiration rate, and growth analysis. The hybrids showed better seedling vigor than PI302921 as they had lower dark respiration rate and higher relative growth rate (RGR) than PI302921. Hybrids grew faster than MO-20, but there was not significant difference between them. Net photosynthesis per unit area increased during three weeks after emergence without difference among the entries, then decreased sharply with leaf age and shading marking much differences among entries Dark respiration rate was very high just after emergence, after which it decreased rapidly until it reached a stable level at 1 week through 3 weeks of age, and then dropped again. In general, dark respiration, photosynthesis, and seedling growth of the hybrid was similar to those if MO-20. Although there are some reports about interspecific hybrids of Lotus species, it still remains as a new area for genetic improvement of seedling vigor of L. corniculatus.atus.

• Journal of Life Science
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• v.11 no.5
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• pp.457-463
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• 2001

A bacterial strain SC-22 which produced alkaline lipase was isolated from salf-fermented shrimps. Strains SC-22 was identified as Staphylococcus xylosus. An alkaline lipase excreted by Staphylococcus xylosus SC-22 was purified by ammonium sulfate predipitation and column chromatography on Sephadex G-100 and DEAE-Sephace. The specific activity of purified lipase was 756U/mg of protein with 17.2% yield. The approximate molecular weight of the purified enzyme was 47 kDa. The partially purified lipase preparation had and optimum temperature of 4$0^{\circ}C$, an optimum pH of 8.0, and a stable of 5~10. Lipase activities were enhanced by salt ions such as $Ca^{2+}$, $Mg^{2+}$,N $a^{2+}$ while inhibited remarkably by heavy metal ions, C $u^{2+}$ and P $b^{2+}$.EX> 2+/.