제조합 대장균에서 과발현된 Citrobacter freundii KCTC2006 유래의 β-Tyrosinase를 이용한 3,4-Dihydroxyphenyl-L-alanine의 생산

이승구,노현수,홍승표,이규종,왕지원,태동년,엄기남,방상구,김영준,성문희 한국미생물생명공학회 ( 구 한국산업미생물학회 ) 1996 한국미생물·생명공학회지 Vol.24 No.1

재조합 대장균에서 대량발현 시킨 Citrobacter freundii KCTC 2006 유래이 효소 β-tyrosinase를 이용하여 pyrocatechol, sodium pyruvate, ammonium acetate로부터 3,4-dihydroxy phenyl-L-alanine을 생산하기 위한 연구를 수행하였다. 이 효소반응에 적합한 온도 및 pH 조건은 각각 18℃와 8.5로 결정되었고, 반응액 중의 ammonium acetate와 sodium pyruvate의 농도는 각각 300 mM, 50 mM 이상으로 조절하는 것이 적합하였다. Pyrocatechol의 경우는 20 mM에서 가장 높은 반응성을 나타냈으나, 기질을 반복적으로 첨가하며 장시간 동안 효소반응을 수행하는 경우에는 pyrocatechol의 고갈을 피하기 위하여, 20 mM에서 50 mM 사이로 조절하였다. 한편, 반응액 중에 ethanol을 10% 첨가한 경우에는 반응속도가약 20% 증가하였다. 이상과 같은 효소반응특성에 기초하여 조제한 기질용액에 β-tyrosinase를 1 unit/㎖ 농도로 가하고, pyrocatechol과 pyruvate가 고갈되지 않도록 간헐적으로 첨가하면서 효소반응을 수행한 결과, 24시간 만에 85.2%의 수율로 31.6g/ℓ의 3,4-dihydroxyphenyl-L-alanine를 생산할 수 있었다. By using the β-tyrosinase of Citrobacter freundii KCTC2006, which was cloned and overexpressed in Escherichia coli, 3,4-dihydroxy phenyl-L-alanine (L-DOPA) was synthesized efficiently from pyrocatechol, sodium pyruvate, and ammonium acetate. Optimal temperature and pH for the reaction were determined to be about 18℃ and 8.5, respectively. The effects of substrate concentrations were also examined at different concentrations of ammonium acetate, sodium pyruvate, and pyrocatechol. Ammonium acetate and sodium pyruvate increased the reaction rate until the concentrations reached to 300 mM and 50 mM, respectively. Although pyrocatechol showed the optimal concentration at 20 mM, it was controlled between 20 mM and 50 mM to avoid the depletion of substrate during the enzymatic synthesis. Based on above results, a reaction medium for the production of L-DOPA was prepared and incubated with 1 unit/㎖ of β-tyrosinase. Pyrocatechol and sodium pyruvate was added to the reaction solution intermittently to avoid the substrate depletion during the enzymatic reaction. After 24 hour of reaction, 31.6 g/ℓ L-DOPA was accumulated in the reaction solution as soluble and precipitated ones and the conversion yield was about 85.2%.

강유전체 Pb(Zr_0.5₂ Ti_0.₄8)O₃박막의 성장 및 물리적 성질

표윤숙,김두회,이장기,김상수 昌原大學校 基礎科學硏究所 2000 基礎科學硏究所論文集 Vol.12 No.-

Ferroelectric Pb(Zr0.52Ti0.48)O3(PZT) thin films coated on Si(100), SiO2/Si(100), Pt/Ti/SiO2/Si(100) and ITO/glass substrates were perpared by sol-gel processing of metal alkoxide solutions and solvents. The XRD investigation shows that the tetragonal phase of polycrystalline PZT was formed by more than four times coating of the concentrated solution and by the heat treatment over 600℃. It was found by SEM that the thin film had an average thickness of about 900Å/coating and surfaces were crack-free and uniform. Capacitance and dielectric loss (tan δ) of PZT thin film were amounted to 0~30nF and 0.05∼20 in the region of 1 kHz ∼ 10 MHz respectively. From the hysteresis loops of PZT/Pt/Ti/SiO2/Si(100) and PZT/ITO/glass thin films, a remnant polarization of 0.2573 μC/cm2, 0.1873 μC/cm2 and a coercive field of 27.78 kV/cm, 24.44 kV/cm were obtained respectively. The band gap energy, refractive index, and extinction coefficient at λ =6235Å of the PZT thin films were 3.74 eV, 1.81 and 0.048 respectively.

拜禮에 관한 一考察 : 「周禮」의 辨九拜를 中心으로 Focused on Jurge's nine sorts of Baerye

李吉杓,表成恩 성신여자대학교 생활문화연구소 1991 生活文化硏究 Vol.5 No.-

Mossbauer 분광법에 의한 Fe₂SiO₄의 연구

이성호,김웅태,채광표,정덕조 建國大學校基礎科學硏究所 1988 理學論集 Vol.13 No.-

Fe₂SiO₄에 관한 X-선 회절실험과 Mossbauer 분광실험을 하였다. X-선 회절실험 결과 본 시료는 olivine group에 속하는 fayalite로서 orthorhombic 구조(??)임을 알 수 있었다. Mossbauer 분광실험은 60K-834K의 온도구간에서 행하여 졌으며, Mossbaure 스펙트럼을 분석한 결과 철은 high spin 2+ 상태임을 알 수 있었고, X-선 회절실험 결과와는 다르게 철이 산소 이온들과 함께 일그러진 octahedron을 형성하고 있음을 알 수 있었다. The Fe₂SiO₄ has been studied by means of X-ray diffractometry and Mossbauer spectroscopy. The analysis of X-ray diffraction pattern shows that Fe₂SiO₄is fayalite of orthorhombic structure(??). The Mossbauer spectra which have been taken between 60K and 834K show that the valence state of iron is ferrous and high spin state and that the iron ions occupy sites of distorted octahedron whereas the X-ray analysis shows it is at a site of regular one.

단백뇨 없는 Mesangial IgM Nephropathy 1예

이강휴,강경표,김원,강명재,박성광,강성귀 대한신장학회 2002 Kidney Research and Clinical Practice Vol.21 No.2

An 51-year-old woman presented with microscopic hematuria without protenuria for long time. Laboratory studies demonstrated the presence of red blood cells in urine, a normal serum IgM level, the absence of antinuclear antibodies, and a normal complement level. Renal biopsy revealed that some glomeruli are enlarged with endocapillary cell proliferation and a few glomeruli exhibit prominent vascular pole of the tufts and segmental increase in mesangial cell and matrix. Immunofluorescence studies demonstrated segmental granular deposits for IgM. Electron microscopy showed well-preserved foot process associated with focal effacement. Biopsy findings were consistent with IgM nephropathy. We present this case to promote understanding of the pathogenesis of IgM nephropathy. (Korean J Nephrol 2002;21(2):317-321)

sol-gel법을 이용한 ?? 강유전체 박막의 성장과 특성

표윤숙,이장기,김상수 昌原大學校 基礎科學硏究所 1999 基礎科學硏究所論文集 Vol.11 No.-

We have developed a simple and rapid method for the synthesis of a precursor solution used in the production of ?? thin films of the layered-perovskite phase ??. Precursor solution preparation takes less than 30 min and involves the generation of two solutions : (a) Bi(O₂CMe)₃dissolved in pyridine and (b) ?? added to Sr(O₂CMe)₂and than solutbilized by HO₂CMe. After stirring separately for 10 min, these solutions are combined, stirred for an additional 10 min, and used without any further modifications. Films of the layered-perovskite phase were formed at temperatures as low as 700℃. Ferroelectric testing of SBN films, films, fired at 800℃ reveals standard hysteresis loop with no fatigue for up to 4×10 cycles.

지황의 잎조직 절편으로부터 식물체의 재분화

이혜정,표병식,황성진 東新大學校 2003 論文集 Vol.13 No.-

Adventitious shoots were directly induced from leaf explants of R. glutinosa, an important medicinal plants. The medium was Murasige and Skoog(MS) supplemented with cytokinins, alone or in combination with auxins. The optimum shoot induction medium contained 1 mg/L BA and 2 mg/L IAA, on which 93% adventitious shoot buds per leaf explants were obtained. Shoots were successfully rooted using plant grow regulators(PGRs)-free 1/2MS medium, and regenerated plants were successfully transferred to soil.

스포츠 스폰서십과 구매의도의 관계

이표상 한국학교체육학회 2003 한국학교 체육학회지 Vol.13 No.2

본 연구는 기업의 스포츠 스폰서십 활동에 대한 소비자들의 인식을 살펴보고, 스포츠 스폰서십이 기업이미지와 소비자의 태도변화, 구매의도에 어떠한 영향을 미치며 스폰서십을 통한 이미지 및 태도변화가 구매의도에 미치는 영향력이 소비자들의 기업인지 정도에 따라 차이가 있는가를 살펴봄으로써 스포츠 스폰서십의 효과와 구매의도의 관계를 규명하는데 목적을 두었다. 연구 대상자는 2003년 서울에 거주하고 있는 대학생 및 직장인들로 하였으며, 표집은 편의 표본추출법 (convenience sampling method)을 사용하여 표본을 추출하였다. 본 조사는 스스로 설문지를 읽고 응답하게 하는 자답식 설문조사방법을 사용하였다. 통계분석은 설문지의 전산처리를 위하여 SPSS(Statistical Packages for Social Science)를 이용하였다. 수집된 자료는 먼저 측정항목들의 신뢰성(reliability) 측정하기 위해 Cronbach's alpha 값을 이용하여 분석하였고, 기업이미지, 광고태도, 제품태도의 변화를 측정하기 위해 ANOVA(One-Way ANOVA, 2-Way ANOVA)와 T-test를 실시 하였으며, 스포츠 스폰서십에 의한 이미지 및 광고태도 ?제품태도가 구매의도에 미치는 영향에 대한 가설을 검증 하기 위해 회귀분석을 실시한 결과 다음과 같은 결론을 얻었다. 첫째, 스포츠 스폰서십 메시지는 구매의도에 긍정적인 영향을 미치는 것으로 나타났다. 둘째, 기업인지도가 높은 기업보다 낮은 기업에서 스포츠 스폰서십이 구매의도에 미치는 영향이 더 큰 것으로 나타났다. 셋째, 스포츠 스폰서십의 효과는 기업의 인지성 정도에 따라 다르게 나타나며 인지도가 높은 기업의 경우에는 스폰서십 메시지 제시이후에 광고태도는 구매의도에 영향을 미치지 않으며, 인지도가 낮은 기업의 경우에는 스폰서십 메시지 제시 전에는 기업이미지가 구매의도에 영향을 미치지 않지만 스폰서십 메시지 제시 후에는 기업이미지가 구매의도에 영향을 미친다는 것을 알 수 있다. The purpose of this study is to investigate the relationship between sports sponsorship and purchase intention. For this purpose, it was investigated that how sports sponsorship affects enterprise awareness, consumer attitude, and purchase intention and if the change of enterprise awareness and consumer attitude through sponsorship differ in purchase intention according to enterprise awareness level. By diversified measurement on effect of Sports sponsorship, we get results as follows. ANOVA analysis and t-test were carried out to survey how sports sponsorship affects purchase intention and if the influence on purchase intention according to enterprise awareness level differs. First, it was appeared that sponsorship message had a positive influence on purchase intension. Second, the influence that sponsorship affects purchase intention was high in corporation which recognition degree was low than corporation which recognition degree was high. Third, regression analysis was put in force to search how the change of enterprise awareness and consumer attitude through sports sponsorship affect purchase intention of consumer. It was appeared that in case of enterprise which recognition degree is high, enterprise awareness, attitude-toward-the-ads, and brand attitude had an influence on purchase intention before presented sponsorship message. But in case of presented sponsorship message, only enterprise awareness and brand attitude had an influence on purchase intention and this influence was higher than before message was presented. In case of enterprise which recognition degree is low, attitude-toward-the-ads and brand attitude had an influence on purchase intention, but on the other hand enterprise awareness didn't have a significant influence before presented sponsorship message. But after presented sponsorship message, it was showed that enterprise awareness, attitude-toward-the-ads, and brand attitude had an influence on purchase intention. This means that enterprise awareness through sports sponsorship affects purchase intention in case of enterprise which recognition degree is low

TSC 기둥-보 접합부의 거동에 관한 실험적 연구

표현석,김성배,김상모,이창남,김상섭,김규석 대한건축학회 2004 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.24 No.1(구조계)

Connection is necessary element of every structure. Connection is important element to increase composition rate of composite beam. Welding joint has been used at composit beam-column connection. Welding joint's quality control is harder than high strength bolt's one. This study based on the experiments of 4 specimens by beam-column connection test. In this paper, we analyze behavior of composite beam-column connection through an experimental study and wish to present application possibility to TSC beam.

전라남도 화순군 일대의 산림조류상

이두표,김상진 호남대학교 산업기술연구소 2005 산업기술연구논문집 Vol.12 No.-