• 식물조직배양학회지
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• 제25권1호
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• pp.45-50
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• 1998

꽃양배추의 하배축 조직을 proteinase inhibitor II 유전자가 도입된 Agrobacterium tumefaciens LBA 4404와 2일간 pH 5.5로 조절된 MS 액체배지에서 공동배양후 carbenicillin 500mg/L kanamycin 20mg/L와 BA 1mg/L가 함유된 MS 재분화배지에 옮겼다. 이들 조직을 매 2주마다 계대배양하였으며 약 4주후에 kanamycin 저항성 개체를 얻었다. 형질전환된 것으로 추정되는 식물체는 kanamycin 30mg/L가 함유된 선발배지에서 생존하였다. PCR 분석결과, PI-II 유전자가 형질전환체의 게놈상에 삽입되어 있음을 확인하였다. 형질전환체의 Southern blot 분석을 통하여 ECL-labelling된 PI-II 유전자와 동일한 것으로 판단되는 약 500bp 위치에서 밴드를 확인할 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제21권2호
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• pp.204-211
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• 2011

To yield high concentrations of protein expressed by genetically modified Escherichia coli, it is important that the bacterial strains are cultivated to high cell density in industrial bioprocesses. Since the expressed target protein is mostly accumulated inside the E. coli cells, the cellular product formation can be directly correlated to the bacterial biomass concentration. The typical way to determine this concentration is to sample offline. Such manual sampling, however, wastes time and is not efficient for acquiring direct feedback to control a fedbatch fermentation. An E. coli K12-derived strain was cultivated to high cell density in a pressurized stirred bioreactor on a pilot scale, by detecting biomass concentration online using a capacitance probe. This E. coli strain was grown in pure minimal medium using two carbon sources (glucose and glycerol). By applying exponential feeding profiles corresponding to a constant specific growth rate, the E. coli culture grew under carbon-limited conditions to minimize overflow metabolites. A high linearity was found between capacitance and biomass concentration, whereby up to 85 g/L dry cell weight was measured. To validate the viability of the culture, the oxygen transfer rate (OTR) was determined online, yielding maximum values of 0.69 mol/l/h and 0.98mol/l/h by using glucose and glycerol as carbon sources, respectively. Consequently, online monitoring of biomass using a capacitance probe provides direct and fast information about the viable E. coli biomass generated under aerobic fermentation conditions at elevated headspace pressures.

• Preventive Nutrition and Food Science
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• 제19권4호
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• pp.343-347
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• 2014

The present study investigated the effects of Vaccinium uliginosum L. (bilberry) on the learning and memory impairments induced by amyloid-${\beta}$ protein ($A{\beta}P$) 1-42. ICR Swiss mice were divided into 4 groups: the control ($A{\beta}40$-1A), control with 5% bilberry group ($A{\beta}40$-1B), amyloid ${\beta}$ protein 1-42 treated group ($A{\beta}1$-42A), and $A{\beta}1$-42 with 5% bilberry group ($A{\beta}1$-42B). The control was treated with amyloid ${\beta}$-protein 40-1 for placebo effect, and Alzheimer's disease (AD) group was treated with amyloid ${\beta}$-protein 1-42. Amyloid ${\beta}$-protein 1-42 was intracerebroventricular (ICV) micro injected into the hippocampus in 35% acetonitrile and 0.1% trifluoroacetic acid. Although bilberry added groups tended to decrease the finding time of hidden platform, no statistical significance was found. On the other hand, escape latencies of $A{\beta}P$ injected mice were extended compared to that of $A{\beta}40$-1. In the Probe test, bilberry added $A{\beta}1$-42B group showed a significant (P<0.05) increase of probe crossing frequency compared to $A{\beta}1$-42A. Administration of amyloid protein ($A{\beta}1$-42) decreased working memory compared to $A{\beta}40$-1 control group. In passive avoidance test, bilberry significantly (P<0.05) increased the time of staying in the lighted area compared to AD control. The results suggest that bilberry may help to improve memory and learning capability in chemically induced Alzheimer's disease in experimental animal models.

• 생명과학회지
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• 제19권3호
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• pp.378-383
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• 2009

본 연구는 Agrobacterium을 이용한 효율적인 호접란 형질 전환 시스템의 확립을 위해 실시하였고, 호접란 PLB의 대량증식을 위한 배지 조성은 하이포넥스 기본 배지에 활성탄 1g/l, 티아민 0.1 mg/l 및 sucrose 30 g/l을 배지에 첨가한 경우 PLB가 안정적으로 증식되었다. 계대 배양시 PLB 절단 방법이 PLB의 생존과 증식에 큰 영향을 미치며, PLB 위쪽으로 부터 1/3 부위를 절단하여 계대 배양한 경우 90% 이상의 가장 높은 증식률을 나타났다. Agrobacterium 접종 시 균이 묻어 있는 침으로 PLB를 찔러 상처를 내는 dipping 방법을 이용하여 형질전환 효율을 높일 수 있었다. Agrobacterium 배양액의 흡광도 값이 0.8일 때 형질전환 효율이 가장 높았고, 형질전환된 PLB의 선발은 1 mg/l 정도의 저농도 hygromycin을 함유한 배지에 계대배양 하는 것이 효율적이었다. 호접란 형질전환체를 먼저 GUS assay를 통하여 선발하였고, 선발된 개체로부터 genomic DNA를 추출하여 GUS 특이적 primer와 probe로 PCR과 Southern blot 분석을 수행하고 유전자의 도입여부를 조사한 결과 GUS 염색된 형질전환체에서 정상적으로 GUS 유전자가 도입된 것을 확인할 수 있었다.

• 한국미생물·생명공학회지
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• 제26권6호
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• pp.562-565
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• 1998

Nisin-producing and nisin resistant L. lactis subsp. lactis ATCC7962 harbored six plasmids. To find a plasmid containing a nisin resistant gene, these plasmids were transformed into L lactis LM0230 of plasmid-free and nisin sensitive strain. After screening on nisin selection media containing nisin (150 $\mu\textrm{g}$/$m\ell$), several nisin resistant transformants were obtained and the level of nisin resistance was very similar to that of wild type L lactis subsp. lactis ATCC7962. A 26.5 kb plasmid, named as pCS100, which confers resistance to nisin, was identified in transformants. The pCS100 was digested with EcoRI and Southern blot hybridization was done with nisI probe to localize the nisin resistant gene. A 4 kb EcoRI fragment showed a strong positive signal, and it was cloned into pBluescript for the potential selection marker.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.III
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• pp.543-550
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• 2000

The objective of this research was to study the effect of contact force of ultrasonic probe on the ultrasonic attenuation measurement of radish. The relationship between ultrasonic attenuation (y) and contact force (x) for radish can be expressed as equation y=a+bLn(x), where a=8.7194+2.l68x(porosity) and b =-9.9188+0.0075 ${\times}$ (volume). The relationship between ultrasonic power spectrum (y) and contact force (x) for radish is also represented by equation y=a+bLn(x), where a= 60.l965-1.47l4${\times}$(porosity). The coefficient b has no significant relation with radish properties.

• Toxicological Research
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• 제28권1호
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• pp.67-71
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• 2012

Trace uranium detection measurement was performed using DNA immobilized on a graphite pencil electrode(DGE). The developed probe was connected to the portable handheld voltammetric systems used for seawater analysis. The sensitive voltammogram was obtained within only 30 s accumulation time, and the anodic stripping working range was attained at 100~800 ${\mu}g/l$ U and 10~50 ${\mu}g/l$. The statistic relative standard deviation of 30.0 mg/l with the $15^{th}$ stripping was 0.2115. Here, toxicological and analytical application was performed in the seawater survey in a contaminated power plant controlling water. The results were found to be applicable for real-time toxicological assay for trace control.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1996년도 춘계학술발표회논문집(4)
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• pp.432-437
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• 1996

The observed characteristics of magnetic oscillations in L-H transition and disruption are described. Two kinds of MHD magnetic probes are used in order to cover broadband frequency range from 1.3 kHz to 300 kHz in the H-mode. Depending on the probe's position and frequency, different characteristics are observed. Precursor like oscillation in L-H transition, and the difference between sawtooth and ELM are discussed. All disruptions during the current rising phase are related with m＝2 or m＝3 mode. Different disruption characteristics for different operation conditions could be found in the MHD probes.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 C
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• pp.1553-1555
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• 2003

Coatings on glass with highly transparent conducting oxide films(TCOs) are performed mostly by using indium tin oxide(ITO). This Oxide material is very common for applications where both high electrical conductivity. Photovoltaic cells, transparent electrical heater, selective optical filter, and a optical transmittance are essential. In this study, ITO thin films were deposited on $SiO_2$/soda-line glass plates by a dc magnetron sputtering technique. The crystallinity and electrical properties of the films were investigated by X-ray diffraction(XRD), atomic force microscopy(AFM) scanning and 4-point probe. The optical transmittance of ITO films in the range of 300-800nm were measured with a spectrophotometer. As a result, we obtained polycrystalline structured ITO films with (222), (400), and (440) peak. Transmittance of all the films were higher than 90% in the visible range.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 춘계학술발표강연 및 논문개요집
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• pp.100-100
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• 2003

본 연구에서는 Si에 Mn을 첨가한 Si$_{l-x}$Mn$_{x}$ 박막의 전기적 및 자기적 특성을 조사하였다. Si$_{l-x}$Mn$_{x}$ 박막은 MBE(Molecular Beam Epitaxy)를 이용하여 native oxide층을 제거하지 않은 (100)Si wafer 위에 성장하였다. Substrate 온도는 50$0^{\circ}C$로 하였으며, 첨가한 Mn 농도는 20%에서부터 80%까지였다. 전기적 특성은 Hall, 4-point probe를 통하여 측정하였고, 자기적 특성은 VSM, FMR, SQUID을 이용하여 측정하였다. 상 분석은 XRD, TEM을 이용하여 관찰하였다 Si$_{l-x}$Mn$_{x}$ 박막은 Hall 측정 결과 상온에서 P-type carrier를 가지며, 비저항은 반도체 영역인 7.6$\times$$10^{-4}$~4.2$\times$$10^{-2}$(ohm-cm)의 값을 가진다. 상온 VSM, 측정결과 Mn의 양이 52% 첨가 시 포화 자화 값이 가장 높은 40emu/cc를 가지며, Mn의 양이 증가할수록 포화 자화 값이 증가하다 다시 감소하는 경향을 가진다. FMR, SQUID 측정에서도 이러한 경향을 확인할 수 있었다 특히, SQUID 분석 결과 두 개 이상의 자성 상이 존재하는 것을 관찰할 수 있었다. XRD, TEM 관찰결과, Si$_{l-x}$Mn$_{x}$은 poly crystal로 성장하였으며, Mn 농도에 따라 여러 상들이 관찰되었다.따라 여러 상들이 관찰되었다.