• 생명과학회지
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• 제14권3호
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• pp.391-395
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• 2004

B. stearothermophilus NO2의 CGTase 유전자 (cgtS)를 구성적 $P_{JH}$ promoter 하류에 subcloning 하여 재조합 plasmid pIH-CGT1 (8.14 kb)을 구축하고 B. subtilis DB431에 형질 전환하였다. B. subtilis DB431/pJH-CGT1를 5가지 배지(LB, 2${\times}$LB, 5% molasses+2% CSL, CS, LBG)로 flask 배양하여 균체증식과 CGTase발현량 및 분비국재성을 조사하여 최적 배지를 결정하였다. 그 중 〔5% molasses+2% CSL〕 배지에서 9시간에 1.8 unit/$m\ell$의 CGTase가 발현$.$생산되었다. 이 결과를 토대로 3. subtilis DB431/pJH-CGT1를 〔10% molasses + 5% corn steep liquor〕 배지에서 발효조 회분 배양한 결과, 30시간 배양시 CGTase의 최대 발현량은 4.2 unit/$m\ell$, 90%의 분비 효율, 90% 이상의 plasmid 안정성을 나타내었다. 저렴한 산업용 molasses 배지로 발효조 회분배양시 플라스크 배양보다 균체증식과 CGTase 발현량이 2배 이상의 증가된 값을 얻었다.

• BMB Reports
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• 제35권4호
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• pp.428-431
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• 2002

The often-encountered problem of disrupting bacteria for the purpose of extracting soluble protein has generated various methods. Many require specialized equipment. Very often, especially during preliminary studies, investigators need a simple, fast, and inexpensive method for cell disruption that preserves biological activity. This paper compares some simple and inexpensive methods for cell disruption, such as bead-vortexing, freesing-thawing, French pressing, and sonication. It also provides some tips to increase protein yield and preserve biological activity. If performed under optimal conditions, bead-vortexing gives protein yields that are comparable to French pressing and sonication. It also preserves the activities of labile enzymes and releases periplasmic enzymes. Vortexing with glass beads appears to be the simplest method for cell disruption.

• 한국식품영양과학회지
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• 제26권6호
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• pp.998-1005
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• 1997

Kimchi showed protective effect from oxidative damage generated by hydrogen peroxide and paraquat. To investigate the major components of kimchi which reduce the cytotoxicity against reactive oxygen species, keratinocyte(A431, epidermoid carcinoma, human) and fibroblast(CCD-986SK, normal control, human) were cultured under oxidative stress condition provoked by paraquat, a superoxide anion generator, and hydrogen peroxide in the absence or presence of kimchi ingredients. Most keratinocyte and fibroblast cells were killed by hydrogen peroxide and paraquat over 1mM concentration, but kimchi ingredients showed protective effects from oxidative damage generated by hydrogen peroxide and onion, among those, garlic showed the most remarkable preventive effect. Most of kimchi ingredients showed protective effect against paraquat, especially leek notably increased cell survival. For fibroblast cells, ginger had the preventive effect against paraquat, especially leek notably increased cell survival. For fibroblast cells, ginger had the preventive effect from cell killing by high dose of hydrogen peroxide, but most ingredients were not effective against paraquat.

• The Korean Journal of Physiology and Pharmacology
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• 제13권6호
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• pp.431-436
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• 2009

The role of apurinic/apyrimidinic endonuclease1/redox factor-1 (Ref-1) on the lead (Pb)-induced cellular response was investigated in the cultured endothelial cells. Pb caused progressive cellular death in endothelial cells, which occurred in a concentration- and time-dependent manner. However, Ref-1 overexpression with AdRef-1 significantly inhibited Pb-induced cell death in the endothelial cells. Also the overexpression of Ref-1 significantly suppressed Pb-induced superoxide and hydrogen peroxide elevation in the endothelial cells. Pb exposure induced the downregulation of catalase, it was inhibited by the Ref-1 overexpression in the endothelial cells. Taken together, our data suggests that the overexpression of Ref-1 inhibited Pb-induced cell death via the upregulation of catalase in the cultured endothelial cells.

• 한국축산식품학회지
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• 제28권4호
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• pp.431-436
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• 2008

The impact of storage on the neuroprotective effects against $A\beta$-induced cell death and physicochemical characteristics of milk fortified with BF-7 were investigated. The BF-7 milk exerted protection of neuronal cells SK-N-SH from amyloid beta ($A\beta$)-induced neuronal stress. Our results showed that incubation of the cell with pretreated BF-7 milk, significantly attenuated apoptotic stress by $A\beta$, considered in cell morphology and nucleus shape. The general compositions were maintained consistently in BF-7 fortified milk (BF-7 milk). The BF-7 did not make any disturbance on pH and titratable acidity. The color change was not detected, either. Also, any microorganism had not been detected with more than 7 days storage at $4^{\circ}C$. In sensory evaluation study. the average scores of each sensory attribute were quite similar with plain milk. In conclusion, our results strongly indicate that BF-7 characteristics are quite adequate to be included in milk and BF-7 milk is still working well on neuro-protection, result in enforcing our brain and delaying neurodegeneration.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.431-431
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• 2016

Typical Cu(In,Ga)Se2 (CIGS)-based solar cells have a buffer layer between CIGS absorber layer and transparent ZnO front electrode, which plays an important role in improving the cell performance. Among various buffer materials, chemical bath deposition (CBD)-ZnS is being steadily studied to alternative to conventional CdS and the efficiency of CBD-ZnS/CIGS solar cell shows the comparable values with that of CdS/CIGS solar cell. The intriguing thing is that reversible changes occur after exposure to illumination due to the metastable defect states in completed ZnS/CIGS solar cell, which induces an improvement of solar cell performance. Thus, it implies that the understanding of metastable defects in CBD-ZnS/CIGS solar cell is important issue. In this study, we fabricate the ITO/i-ZnO/CBD-ZnS/CIGS/Mo/SLG solar cells by controlling the NH4OH mole concentration (from 2 M to 3.5 M) of CBD-ZnS buffer layer and observe their conversion efficiency with and without light soaking for 1 hr. From the results, NH4OH mole concentration and light exposure can significantly affect the CBD-ZnS/CIGS solar cell performance. In order to investigate that which layer can contain metastable defect states to influence on solar cell performance, impedance spectroscopy and capacitance profiling technique with exposure to illumination have been applied to CBD-ZnS/CIGS solar cell. These techniques give a very useful information on the density of states within the bandgap of CIGS, free carriers density, and light-induced metastable effects. Here, we present the rearranged charge distribution after exposure to illumination and suggest the origin of the metastable defect states in CBD-ZnS/CIGS solar cell.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2005년도 제24회 춘계학술대회논문집
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• pp.431-434
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• 2005

데토네이션 파의 셀 구조를 모사하기 위한 격자 해상도 요구 조건을 파악하기 위하여 여러 영역의 데토네이션 현상에 대하여 반응 속도 상수와 격자 해상도를 바꾸어가며 일련의 해석을 수행 하였다. 서로 다른 영역의 데토네이션 현상에 대하여 정상 상태 ZND 구조와 계산 결과를 비교하여 살펴봄으로써, 최소 격자 크기와 계산 영역의 크기에 대한 결론을 도출하였다.

• KSBB Journal
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• 제13권4호
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• pp.431-437
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• 1998

Optimal media and cultural conditions for the production of prodigiosin-like pigment were established using Serratia sp. KH-95. Glucose and phosphate(K2PO4) stimulated the cell growth, but inhibited the production of pigment at concentration levels of above 10 g/L and 2.0 g/L, respectively. Addition of soy been oil or rice oil to the production medium accelerated cell growth up to more than 2-3 times, but the production of prodigiosin increased about 15-20% in spite of the good cell growth. The effect of pH on the production of pigment was investigated in a 5 liter-bioreactor. When the pH of culture broth was maintained below 8.0, most of pigment was attached to the surface of cells. When the pH of culture broth was above 8.5, however, about 70% of total pigment was suspended in the supernatant of the broth. The cell growth and production of pigment were inhibited at dissolved oxygen concentration of below 10% of air-saturation.

• 한방안이비인후피부과학회지
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• 제37권1호
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• pp.1-16
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• 2024

Objectives : We aimed to study the effect of Smilax China L.(SCL), which has anti-inflammatory, antioxidant, and anticancer effects, on the growth of skin cancer cells. Methods : HaCaT cells, a normal human cell line, and skin cancer cells including A431, SK-MEL-5 and SK-MEL-28 cells were treated with Smilax China L. ethanol extract(SCL-EtOH) at concentrations of 5, 10, 20 and 40㎍/㎖. Meanwhile, JB6 Cl41, a normal mouse epithelial cell line, was treated with epidermal growth factor(EGF) and phorbol 12-myristate 13-acetate(TPA), an inflammatory factor, to induce cell transformation and treated with SCL-EtOH. In addition, we treated SK-MEL-5 and SK-MEL-28 cells with SCL-EtOH at various concentrations and checked the effect on the cell cycle. Results : As a result, it showed no toxicity to HaCaT cells up to the highest concentration of 40㎍/㎖, and significant cell growth inhibition to A431, SK-MEL-5 and SK-MEL-28 cells in a time- and concentration-dependent manner. In addition, as a result of checking the shape of skin cancer cells according to SCL-EtOH treatment, it was observed that as the concentration increased, the number of normally attached and growing cells decreased and the shape of the cells changed. Colony formation was significantly reduced in a concentration-dependent manner in JB6 Cl41 cells treated with EGF or TPA. Flow cytometry analysis with propidium iodide(PI) staining showed that SCL-EtOH induced the G2/M phase arrest. We further confirmed the decrease in Cyclin B1 expression and increase in p27 expression associated with the G2/M phase of the cell cycle through western blot analysis. Flow cytometry analysis confirmed that SCL-EtOH induced cell apoptosis. Furthermore, through Western blot analysis, it was observed that the expression of cleaved-caspase-7, which is related to apoptosis, increased. Finally, it was confirmed that the expression of COX-2, an inflammatory marker protein, decreased in a concentration-dependent manner with SCL-EtOH. Conclusions : Through the above results, we have established a basis for applying SCL to the treatment of skin cancer.

• 전력전자학회논문지
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• 제19권5호
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• pp.431-439
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• 2014

The two-phase interleaved bidirectional DC-DC converter (TIBDC) is a very attractive solution to problems related to battery energy storage systems. However, the hard-switching TIBDC increases the switching loss and electromagnetic interference noise when the switching frequency increases. Hence, a soft-switching technique is required to overcome these disadvantages. In this study, a novel TIBDC with zero-voltage transition (TIBDC-ZVT) is proposed. Soft switching in the boost and buck main switches is achieved through a resonant cell that consists of a single resonant inductor and four auxiliary switches. Given its single resonant inductor, the proposed TIBDC-ZVT has a reduced size and can easily be implemented. The validity of the proposed TIBDC-ZVT is verified through experimental results.