• 미생물학회지
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• 제42권4호
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• pp.313-318
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• 2006

가정에서 제조된 된장으로부터 cellulase 생산균으로 분리된 고온성 WL-12는 형태적 특성, 생화학적 성질 및 16S rRNA의 염기서열에 근거하여 Bacillus licheniformis로 동정되었다. B. licheniformis WL-12의 cellulase 유전자를 클로닝하여 그 염기서열을 결정한 결과 cellulase 유전자(celA)는 517 아미노산으로 구성된 단백질을 코드하며 1,551 뉴클레오티드로 이루어졌다. 아미노산 잔기배열을 분석한 결과 WL-12의 cellulase는 활성영역과 cellulose 결합영역으로 구성되어 있었으며, glycosyl hydrolase (GH) family 5에 속하는 B. licheniformis, B. subtilis와 B. amyloliquefaciens의 cellulase와 높은 상동성을 보였다. 클론된 celA를 발현용 vector에 도입하여 B. subtilis에서 발현시켜 cellulase 최대생산성이 7.0 units/ml에 이르렀다.

• Journal of Animal Science and Technology
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• 제45권1호
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• pp.13-22
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• 2003

성장호르몬 유전자는 하나의 작은 공통 선조 유전자로부터 아주 오랜 기간동안 유전자 중복에 의해 진화되어 온 그룹들 중의 하나이다. 이들에 속하는 유전자들은 동물 종간에 구조적인 상동성과 기능적 공통성 등 유사성이 비교적 높게 나타난다. 이런 연구결과들을 근거로 하여 소 성장호르몬 유전자에서 아미노산을 암호화하는 영역으로부터 새로운 아미노산의 변이(missense mutation)를 검출하였고, 이 변이의 대립유전자 빈도는 소(cattle)의 종(species) 및 품종의 지리적 분포에 따라 일정한 경향 치를 보여 주었다. 한편 변경되어진 아미노산은 Tryptophan으로 이는 생물체에 존재하는 많은 단백질들을 구성하는 아미노산중에서도 그 출현빈도가 가장 낮은 것이다. 또한 검출된 변이는 성장호르몬이 그의 수용체와 강하게 결합하는 부위로서, 성장호르몬의 구조적 변이를 초래하여 수용체와의 결합이 비정상적으로 이루어져, 이후 성장호르몬이 표적세포로의 신호전달과 같은 역할을 제대로 수행치 못하게 되고, 이로 인하여 가축의 표현되어지는 경제형질에 영향을 미칠 것으로 추정된다. 그러므로 이러한 대립유전자를 보유하는 개체는 집단에서 제거하는 방법에 의한 개량이 가능할 것으로 사료된다.

• 한국방재학회 논문집
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• 제7권1호통권24호
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• pp.1-9
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• 2007

본 연구는 국내에 시공된 조적조 건축물의 특징을 반영한 조적벽체의 반복가력과 모의진동대 실험을 통해 얻어진 결과를 근거로 하여 유리섬유로 보강된 보강조적벽체의 전단내력식을 제안하는 것을 목적으로 한다. 실험결과, 개구부가 없는 조적벽체의 파괴를 지배하는 모드는 Rocking이였고, 개구부가 있는 경우는 개구부 주변에 균열이 집중되었다. 비보강 조적벽체의 전단내력식은 UBC에서 제시한 식이 실험과 가장 유사한 값을 보였다. 본 연구를 통해 제안되어지는 유리섬유 보강조적벽체의 전단내력식은 다음과 같다. $$V_n=0.02A_n{\sqrt{f'_m}}+0.022b_gh_g(1+2{\alpha})^3{\sqrt{f_g}}(N/mm^2)$$.

• Journal of Microbiology and Biotechnology
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• 제31권10호
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• pp.1446-1454
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• 2021

Herein, we cloned and expressed an endo-β-1,4-glucanase gene (celA1805) from Bacillus subtilis B111 in Escherichia coli. The recombinant celA1805 contains a glycosyl hydrolase (GH) family 8 domain and shared 76.8% identity with endo-1,4-β-glucanase from Bacillus sp. KSM-330. Results showed that the optimal pH and temperature of celA1805 were 6.0 and 50℃, respectively, and it was stable at pH 3-9 and temperature ≤50℃. Metal ions slightly affected enzyme activity, but chemical agents generally inhibited enzyme activity. Moreover, celA1805 showed a wide substrate specificity to CMC, barley β-glucan, lichenin, chitosan, PASC and avicel. The K_m and V_max values of celA1805 were 1.78 mg/ml and 50.09 µmol/min/mg. When incubated with cellooligosaccharides ranging from cellotriose to cellopentose, celA1805 mainly hydrolyzed cellotetrose (G4) and cellopentose (G5) to cellose (G2) and cellotriose (G3), but hardly hydrolyzed cellotriose. The concentrations of reducing sugars saccharified by celA1805 from wheat straw, rape straw, rice straw, peanut straw, and corn straw were increased by 0.21, 0.51, 0.26, 0.36, and 0.66 mg/ml, respectively. The results obtained in this study suggest potential applications of celA1805 in biomass saccharification.

• Journal of Microbiology and Biotechnology
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• 제31권2호
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• pp.272-279
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• 2021

Two genes encoding probable α-ʟ-arabinofuranosidase (E.C. 3.2.1.55) isozymes (ABFs) with 92.3% amino acid sequence identity, ABF51A and ABF51B, were found from chromosomes 3 and 5 of Saccharomycopsis fibuligera KJJ81, an amylolytic yeast isolated from Korean wheat-based nuruk, respectively. Each open reading frame consists of 1,551 nucleotides and encodes a protein of 517 amino acids with the molecular mass of approximately 59 kDa. These isozymes share approximately 49% amino acid sequence identity with eukaryotic ABFs from filamentous fungi. The corresponding genes were cloned, functionally expressed, and purified from Escherichia coli. SfABF51A and SfABF51B showed the highest activities on p-nitrophenyl arabinofuranoside at 40~45℃ and pH 7.0 in sodium phosphate buffer and at 50℃ and pH 6.0 in sodium acetate buffer, respectively. These exoacting enzymes belonging to the glycoside hydrolase (GH) family 51 could hydrolyze arabinoxylo-oligosaccharides (AXOS) and arabino-oligosaccharides (AOS) to produce only ʟ-arabinose, whereas they could hardly degrade any polymeric substrates including arabinans and arabinoxylans. The detailed product analyses revealed that both SfABF51 isozymes can catalyze the versatile hydrolysis of α-(1,2)- and α-(1,3)-ʟ-arabinofuranosidic linkages of AXOS, and α-(1,2)-, α-(1,3)-, and α-(1,5)-linkages of linear and branched AOS. On the contrary, they have much lower activity against the α-(1,2)- and α-(1,3)-double-substituted substrates than the single-substituted ones. These hydrolases could potentially play important roles in the degradation and utilization of hemicellulosic biomass by S. fibuligera.

• Archives of Plastic Surgery
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• 제35권1호
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• pp.13-19
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• 2008

Purpose: Human adipose tissue-derived mesenchymal stem cells(hATSCs) can be differentiated into multiple mesenchymal lineages, including bone, cartilage, and muscle. And growth hormone play important roles in the normal growth and development of the CNS. In this study, we explored whether the transplanted hATSCs and growth hormones could improve functional recoveries from rats with contusive spinal cord injury. Methods: We divided 30 female rats, which were subjected to a weight driven implant spinal cord injury, into 3 groups with 10 rats each; Group A as a control group, group B with hATSCs transplantation on injured region, and group C with hATSCs transplantation and GH administration for 7 days. Then, we researched their neurologic functional recoveries before and 2, 4, and 8 weeks after transplantation using Basso-Beattie-Bresnahan (BBB) locomotor rating scale. And we checked Y-chromosome positive cells by FISH(Fluorescent in situ hybridization) to identify the survival of transplanted mesenchymal stem cells. Results: After 4 weeks of transplantation, the group B and group C showed significant improvement of neurologic function on BBB locomotor rating scale in comparison with the group A(Group A: $13.1{\pm}0.58$, Group B: $14.6{\pm}0.69$, Group C: $14.9{\pm}0.56$). Moreover, the group C displayed meaningful recovery of neurologic function after 8 weeks in comparison with group B (Group B: $15.7{\pm}0.63$, Group C: $16.5{\pm}1.14$). The group A, the control one, improved for 5 weeks after injury, and had no more recovery. On the other hand, Group B and C showed the improvement of neurologic function continuously for 9 weeks after injury. Conclusion: In this study, we found out that hATSCs transplantation have an effect on neurologic functional recovery of spinal cord injured rat and GH injection seems to bring the synergistic results on this good tendency.

• Journal of Preventive Medicine and Public Health
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• 제37권2호
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• pp.157-165
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• 2004

Objectives : This study aimed to investigate the toxic effects of chromium (VI) on the placental function and reproduction in rats. For the study, the placental prolactin-growth hormone (PRL-GH) gene expression, placental trophoblast cell differentiation and reproductive data were analyzed. Methods : The pregnancies of F344 Fisher rats were checked by the presence of a copulatory plug or sperm in the vaginal smear, which was defined as day 0 of the pregnancy. Pregnant rats were divided into the three groups. The control group was given tap water (chromium level < 0.001 ppm) and the remaining groups were given 250 or 750 ppm of chromium (VI) [as potassium dichromate], from day 7 to 19 of the pregnancy. Rats were sacrificed at days 11 and 20 of pregnancy. The mRNA levels of PRL-GH and Pit-1a and b isotype genes were analyzed by Northern blot hybridization and reverse transcription-polymerase chain reaction (RT-PCR). The hormonal concentration was analyzed by radioimmunoassay, and the differentiation of placental trophoblast cells were observed by histochemical studies. Reproductive data, such as placental and fetal weights, pregnancy period, and litter size, were surveyed at day 20 of pregnancy and after birth. A statistical analysis was carried out using the SAS program (version 8.1). Results : The mRNA levels of the prolactin-growth hormone (PRL-GH) family of genes were dose dependently reduced by chromium exposure. The mRNA levels of Pit-1a and b isotype genes that induce the expression of the PRL-GH family of genes were also reduced by chromium exposure. The PRL-GH hormonal concentration in the rat placenta, fetus and maternal blood were decreased by chromium exposure. In the middle stage of pregnancy (day 11), a high dose of chromium suppressed the differentiation of spongiotrophoblast cells that secret the PRLGH hormones. In the last stage of pregnancy (day 20), a high dose of chromium induced apoptosis of placental cells. Reproductive data, such as placental and fetal weights, litter size, were reduced, but the pregnancy period was extended in the group exposed to chromium compared with the controls. Conclusion : Chromium (VI) disrupts the ordered functions of the placenta, which leads to reproductive disorders in rats.

• 대한수학회보
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• 제46권5호
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• pp.941-947
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• 2009

Let q be a power of 16. Every polynomial $P\in\mathbb{F}_q$[t] is a strict sum $P=A^2+A+B^3+C^3+D^3+E^3$. The values of A,B,C,D,E are effectively obtained from the coefficients of P. The proof uses the new result that every polynomial $Q\in\mathbb{F}_q$[t], satisfying the necessary condition that the constant term Q(0) has zero trace, has a strict and effective representation as: $Q=F^2+F+tG^2$. This improves for such q's and such Q's a result of Gallardo, Rahavandrainy, and Vaserstein that requires three polynomials F,G,H for the strict representation $Q=F^2$+F+GH. Observe that the latter representation may be considered as an analogue in characteristic 2 of the strict representation of a polynomial Q by three squares in odd characteristic.

• 대한기계학회논문집B
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• 제33권5호
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• pp.326-333
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• 2009

Design life-time of a wind turbine is required to be at least 20 years. In the meantime, the wind turbine will experience a lot of load cases such as extreme loads and fatigue loads which will include several typhoons per year and extreme gusts with 50 years recurrence period as well as endless turbulence flow. Therefore, IEC61400-1 specifies design load cases to be considered in the wind turbine design and requires the wind turbine to withstand the load cases in various operational situations. This paper investigates the ultimate loads which the wind turbine will experience for 20 years and their characteristics based on the IEC61400-1 using an aero-elastic software, GH-Bladed. And the performance characteristics of a wind turbine such as electrical power generation and annual energy yield are also investigated.

• 생명과학회지
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• 제25권6호
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• pp.680-685
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• 2015

이전에 토양으로부터 cellulase와 xylanase 생산 균주로 단리하였다. 단리한 균주 유래의 16S rRNA 유전자 및 API 50 kit를 분석한 결과 Bacillus subtilis와 약 99.5%의 높은 상동성을 보였기에 본 균주를 B. subtilis NC1으로 명명하였다. Bacillus subtilis NC1 균주 유래 cellulase와 xylanase 유전자를 cloning 하여 유전자 배열을 규명하였다. 또한, 두 효소의 아미노산 배열을 이용하여 상동성을 검토한 결과 cellulase는 Glycoside hydrolase family (GH) 5 그리고 xylanase는 GH30에 속하는 효소임을 밝혔다. 본 연구에서는 B. subtilis NC1 의 cellulase 생산을 위한 배지성분의 최적 농도를 결정하기 위해 중심합성계획법(central composite design, CCD)을 기반으로 한 반응표면 분석법(Response Surface Methodology) 을 수행하였다. 세가지 독립변수로는 tryptone, yeast extract, 그리고 NaCl이 조사되었다. 반응값에 대하여 분산분석을 실시한 결과 결정계수(R²)는 0.96이었으며 전체 모델에 대한 유의확률이 0.0001로 매우 높은 유의성을 지님을 확인하였다. 반응표면분석법을 통하여 얻어진 B. subtilis NC1의 cellulase 활성을 위한 최적화 배지의 각 변수 농도는 tryptone 2.5%, yeast extract 0.5%, 그리고 NaCl 1.0%로 예측 되었다. 최적화 배지에서의 B. subtilis NC1의 cellulase 활성을 검증한 최적화를 실시하기 이전인 대조구의 cellulase 활성 0.5U/ml와 비교하면 24% 활성이 향상된 0.62U/ml의 높은 활성을 보였다.