• Journal of Microbiology and Biotechnology
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• 제29권3호
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• pp.357-366
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• 2019

We first confirmed the involvement of MalQ (4-${\alpha}$-glucanotransferase) in Escherichia coli glycogen breakdown by both in vitro and in vivo assays. In vivo tests of the knock-out mutant, ${\Delta}malQ$, showed that glycogen slowly decreased after the stationary phase compared to the wild-type strain, indicating the involvement of MalQ in glycogen degradation. In vitro assays incubated glycogen-mimic substrate, branched cyclodextrin (maltotetraosyl-${\beta}$-CD: G4-${\beta}$-CD) and glycogen phosphorylase (GlgP)-limit dextrin with a set of variable combinations of E. coli enzymes, including GlgX (debranching enzyme), MalP (maltodextrin phosphorylase), GlgP and MalQ. In the absence of GlgP, the reaction of MalP, GlgX and MalQ on substrates produced glucose-1-P (glc-1-P) 3-fold faster than without MalQ. The results revealed that MalQ led to disproportionate G4 released from GlgP-limit dextrin to another acceptor, G4, which is phosphorylated by MalP. In contrast, in the absence of MalP, the reaction of GlgX, GlgP and MalQ resulted in a 1.6-fold increased production of glc-1-P than without MalQ. The result indicated that the G4-branch chains of GlgP-limit dextrin are released by GlgX hydrolysis, and then MalQ transfers the resultant G4 either to another branch chain or another G4 that can immediately be phosphorylated into glc-1-P by GlgP. Thus, we propose a model of two possible MalQ-involved pathways in glycogen degradation. The operon structure of MalP-defecting enterobacteria strongly supports the involvement of MalQ and GlgP as alternative pathways in glycogen degradation.

• 대한임상검사과학회지
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• 제47권4호
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• pp.306-312
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• 2015

알러지 반응이 일어나면 histamine이 방출되기 때문에 histamine을 정량 측정함으로써 유발된 알러지의 정도를 확인 할 수 있다. 일반적으로는 항원-항체반응으로 microplate reader를 이용하여 흡광도를 측정하여 정량 한다. 본 연구에서는 histamine 방출량을 측정함에 있어서 일반적인 항원-항체반응과 분석 화학적인 방법으로 HPLC-MS를 이용한 방법을 비교하였다. 세포주는 RBL-2H3를 사용하였고, C48/80으로 자극시켜 알러지를 유발하였다. 유발된 알러지는 ${\beta}$-hexosaminidase의 측정으로 탈 과립을 확인하였으며 실험의 정당성을 위하여 세포독성 능을 확인하였다. Histamine 정량에서 항원-항체반응에 의한 측정의 정량한계는 10.257 ppm이었고, HPLC-MS에 의한 정량한계는 0.020 ppm으로 현저한 차이를 보였다. 알러지 활성 및 항 알러지 실험에 있어서 histamine의 측정은 HPLC-MS를 이용한 분석이 더 정밀하고 정확한 실험인 것을 확인하였다.

• 한국식품과학회지
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• 제24권2호
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• pp.187-192
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• 1992

일반계와 통일계 쌀 전분에 대한 구조적 성질을 조사하고 그 차이점을 비교하였다. 쌀 성분의 호화온도 범위는 일반계가 통일계보다 넓었고 쌀 전분의 최대 흡수파장은 일반계가 통일계 보다 높았다. 고유점도는 전분, 아밀로오스와 아밀로펙틴 모두 일반계가 통일계 보다 낮았다. ${\beta}$-아밀라아제 분해 한도는 전분에서는 차이가 없으나 아밀로오스와 아밀로펙틴은 일반계가 통일계 보다 약간 낮았다. 아밀로펙틴의 평균 사슬 길이와 바깥 사슬 길이는 일반계가 통일계 보다 짧았으나 안쪽 사슬 길이는 차이가 없었다. 열수 가용성 전분과 아밀로오스 함량은 일반계가 통일계 보다 높았다. 또한 열수 가용성 전분을 겔 크로마토그래피한 결과는 품종마다 독특한 용출모양을 보였다.

• 대한수의학회지
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• 제33권4호
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• pp.611-615
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• 1993

젖소에서 progesterone과 testosterone의 측정을 위하여 solid phase 효소면역분석법(酵素免疫分析法)를 개발하였다. 1차 항체로서 $11{\alpha}$-hemisuccinate-progesterone bovine serum albumin과 4-androsten-$17\;{\beta}$-ol-3-one-carboxymethyloxime bovine serum albumin에 대한 토끼 혈청(血淸)을 각각 항혈청(抗血淸)으로 사용하였고, 2차 항체로서 면약 IgG를 사용하였다. Conjugates로서는 각각 progesterone-$11\;{\alpha}$-hydroxy-hemisuccinate-horseradish peroxidase와 4-androsten-$17\;{\beta}$-ol-3-hemisuccinate-horseradish peroxidase를 사용하였다. Progesterone과 testosterone에 대한 최저측정치(最低測定値)는 각각 6.7 pg/well과 1.0 pg/well이었다.

• 열처리공학회지
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• 제17권5호
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• pp.271-277
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• 2004

Zr-xNb alloys (x = 0.2, 0.8, 1.5 wt.%) were prepared to study the characteristics of the phase transformation in Zr-Nb system. The samples were heat treated at ${\beta}$-temperature ($1020^{\circ}C$) for 20 min and then cooled with different cooling rate. The microstructures of the specimens having the same compositions were changed with cooling rate and Nb content. The Widmanst$\ddot{a}$tten structure was observed on the furnace-cooled sample. The relationship between ${\alpha}$-Widmanst$\ddot{a}$tten and ${\beta}$-phase was the {0001}${\alpha}$//{110}${\beta}$, <11$\bar{2}$0>//<111>. The ${\beta}$-phase in Widmanst$\ddot{a}$tten structure of Zr-Nb alloys containing Nb more than solubility limit was identified as ${\beta}_{Zr}$ phase which was a stable phase at high temperature. In the water quenched samples, two kinds of martensite structures were observed depending on the Nb-concentration. The lath martensite was formed in Zr-0.2, 0.8 wt.% Nb alloys and the plate martensite having twins was formed in Zr-1.5 wt.% Nb alloy.

• Journal of Radiation Protection and Research
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• 제43권4호
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• pp.154-159
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• 2018

Background: To prevent small leakage accidents, a real-time and direct detection system for small leaks with a detection limit below that of existing systems, e.g. $0.5gpm{\cdot}hr^{-1}$, is required. In this study, a small-size beta detector, which can be installed inside the reactor containment (CT) building and detect small leaks directly, was suggested and its feasibility was evaluated using MCNPX simulation. Materials and Methods: A target nuclide was selected through analysis of radiation from radionuclides in the reactor coolant system (RCS) and the spectrum was obtained via a silicon detector simulated in MCNPX. A window was designed to reduce the background signal caused by other nuclides. The sensitivity of the detector was also estimated, and its shielding designed for installation inside the reactor CT. Results and Discussion: The beta and gamma spectrum of the silicon detector showed a negligible gamma signal but it also contained an undesired peak at 0.22 MeV due to other nuclides, not the $^{16}N$ target nuclide. Window to remove the peak was derived as 0.4 mm for beryllium. The sensitivity of silicon beta detector with a beryllium window of 1.7 mm thickness was derived as $5.172{\times}10^{-6}{\mu}Ci{\cdot}cc^{-1}$. In addition, the specification of the shielding was evaluated through simulations, and the results showed that the integrity of the silicon detector can be maintained with lead shielding of 3 cm (<15 kg). This is a very small amount compared to the specifications of the lead shielding (600 kg) required for installation of $^{16}N$ gamma detector in inside reactor CT, it was determined that beta detector would have a distinct advantage in terms of miniaturization. Conclusion: The feasibility of the beta detector was evaluated for installation inside the reactor CT to detect small leaks below $0.5gpm{\cdot}hr^{-1}$. In future, the design will be optimized on specific data.

• Journal of Microbiology and Biotechnology
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• 제29권9호
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• pp.1470-1477
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• 2019

${\beta}_2$-adrenergic receptor (${\beta}_2-AR$) was expressed efficiently using Bac-to-Bac Baculovirus Expression System in Sf9 cells as a bio-recognition element for multianalyte screening of ${\beta}$-agonist residues in pork. Sf9 cells were selected as the expression system, and codon optimization of wild-type nucleic acid sequence and time-dependent screening of expression conditions were then carried out for enhancing expression level and biological activity. Under optimum conditions of multiplicity of infection (MOI) = 5 and 48 h post transfection, the protein yield was up to 1.23 mg/ml. After purification by chromatographic techniques, the purified recombinant protein was applied to develop a direct competitive enzyme-linked receptor assay (ELRA) and the efficiency and reliability of the assay was determined. The IC50 values of clenbuterol, salbutamol, and ractopamine were 28.36, 50.70, and $59.57{\mu}g/l$, and clenbuterol showed 47.61% and 55.94% cross-reactivities with ractopamine and salbutamol, respectively. The limit of detection (LOD) was $3.2{\mu}g/l$ and the relevant recoveries in pork samples were in the range of 73.0-91.2%, 69.4-84.6%, and 63.7-80.2%, respectively. The results showed that it had better performance compared with other present nonradioactive receptorbased assays, indicating that the genetically modified ${\beta}_2-AR$ would have great application potential in detection of ${\beta}$-agonist residues.

• Clinical and Experimental Reproductive Medicine
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• 제17권1호
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• pp.45-56
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• 1990

Maternal serum ${\beta}$-specific human chorionic gonadotropin(${\beta}$-hCG) and pregnancy-specific ${\beta}_1$-glycoprotein($SP_1$) levels were determined more than one per week during 11-41 days post embryo transfer(ET) in 21 consecutive pregnancies after in vitro fertilization(IVF), which included 8 normal singleton pregnancies, 3 twin pregnancies, 4 clinical abortions, 1 ectopic pregnancy, and 5 preclinical abortions. The sensitivity of serum ${\beta}$-hCG and $SP_1$ radioimmunoassays was 3mIU/ml and 0.7ng/ml relatively. At the 7th to 8th week of gestation, ultrasonographic confirmation of fetal pole and fetal heartbeat was performed. Both serm ${\beta}$-hCG and $SP_1$ levels showed logarithmic increase, but log[$SP_1$] had more steep rising curve and had wider variation than log[${\beta}$-hCG] in normal singleton pregnancies. In 3 twin pregnancies and one ectopic pregnancy, both serum ${\beta}$-hCG and $SP_1$ levels located within the 95% confidence interval of the mean levels of 8 normal singleton pregnancies(normal range). In 2 clinical abortions which had a fetal pole without heartbeat, serum ${\beta}$-hCG level showed lower limit of the normal range or just below, but all $SP_1$ levels showed within the normal range. In other 2 clinical abortions which were diagnosed as blighted ovum, both serum ${\beta}$-hCG levels from 11 days post-ET and serum $SP_1$ levels from later days compared with ${\beta}$-hCG were below the normal range. In 5 preclinical abortions, serum $SP_1$ levels were within the normal range but serum ${\beta}$-hCG levels were far below the normal range. In conclusion, both serum ${\beta}$-hCG and $SP_1$ levels increased exponentially with similar pattern in normally conceived pregancy after IVF-ET. Both serum ${\beta}$-hCG and $SP_1$ levels could predict outcome of early pregnancy to a certain degree, but log[${\beta}$-hCG] levels had more significant correlation with outcome of pregnancy compared with log[$SP_1$] levels. In addition, ultrasonographic examination of fetal poles and fetal heartbeats gives very important clinical information and prognosis.

• Journal of Radiation Protection and Research
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• 제18권2호
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• pp.17-25
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• 1993

액체섬광 계수기에 대한 $^3H,\;^{14}C,\;^{36}Cl$의 베타선 스펙트럼의 시뮬레이션을 Monte Carlo 법으로 수행하였다. 베타선의 손실에너지는 'continuous slowing down approximation(CSDA)' 모형으로부터 구하였다. 순 베타방출 핵종이 균일하게 용해되어 있는 섬광용액은 $1.25cm{\times}3.5cm$의 원통형 geome try로 가정하였다. $^{14}C,\;^{36}Cl$에 대한 계산결과는 계수효율의 경우 실험 값과 2%의 범위 내에서 잘 일치하였으나 $^3H$에 대해서는 상당한 편차를 나타내었다. 이는 저 에너지 베타선에 대한 섬광용액 자체의 quenching 효과에 기인하는 것으로 판단된다.

• Applied Biological Chemistry
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• 제44권3호
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• pp.197-201
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• 2001

우슬(Achyranthis radix)중 ${\beta}-ecdysone$의 초임계추출법과 용매추출법의 비교를 위해 초임계유체추출(SFE) 및 용매추출 후 초임계유체크로마토그래피(SFC)에 의한 우슬 중 ${\beta}-ecdysone$ 분석을 실시하였다. SFE에 있어서 추출 최적압력은 300 atm이었으며, 온도는 $80^{\circ}C$, 추출량은 100 ml, 보조제인 methanol 함량비율은 20%였다. 우슬에서 ${\beta}-ecdysone$의 분석시 SFC의 최소검출량은 5 ng이었고, SFE의 회수율은 줄기에서는 $90.7{\sim}93.5%$였으며, 뿌리에서는 $77.8{\sim}81.9%$였다. 용매추출의 회수율은 줄기에서는 $76.4{\sim}93.0%$였고 뿌리에서는 $80.6{\sim}93.1%$였다. 우슬의 생육기별 조사에서 ${\beta}-ecdysone$은 주로 뿌리에서 많이 검출되었고 1년생이면서 8월에 수확한 것이 654.9 ppm으로 가장 많이 함유한 것으로 나타났다.