• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.277.2-277.2
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• 2013

Petri dishes and glass slides have been widely used as general substrates for in vitro mammalian cell cultures due to their culture viability, optical transparency, experimental convenience, and relatively low cost. Despite the aforementioned benefit, however, the flat two-dimensional substrates exhibit limited capability in terms of realistically mimicking cellular polarization, intercellular interaction, and differentiation in the non-physiological culture environment. Here, we report a protocol of culturing embryonic rat hippocampal neurons on the electro-spun polymeric network and the results from examination of neuronal cell behavior and network formation on this culture platform. A combinatorial method of laser-scanning confocal fluorescence microscopy and live-cell imaging technique was employed to track axonal outgrowth and synaptic connectivity of the neuronal cells deposited on this model culture environment. The present microfiber-based scaffold supports the prolonged viability of three-dimensionally-formed neuronal networks and their microscopic geometric parameters (i.e., microfiber diameter) strongly influence the axonal outgrowth and synaptic connection pattern. These results implies that electro-spun fiber scaffolds with fine control over surface chemistry and nano/microscopic geometry may be used as an economic and general platform for three-dimensional mammalian culture systems, particularly, neuronal lineage and other network forming cell lines.

• 한국축산식품학회지
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• 제30권4호
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• pp.617-625
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• 2010

The objective of this study was to determine the effect of reheating methods on the color characteristics of precooked pork patties with various NaCl and phosphate levels. NaCl/phosphate levels for each formulation were as follows; N1 (1% NaCl), N1+P (1% NaCl+0.3% phosphate), N2 (2% NaCl), and N2+P (2% NaCl+0.3% phosphate). The reheating methods used were by electric grill and microwave oven. The surface color of the patties reheated by microwave showed more brown and less-intense red, and the phosphate-treated patties reheated by microwave were more reddish and less brownish. With increased amounts of added NaCl and phosphate, the internal color of patties was more reddish, and the phosphate-treated patties reheated by microwave had more brown than those reheated by electric grill. Among all of the treatments, there were no significant differences in surface color, internal color, and overall appearance. Thus, the color changes in reheated patties were influenced by reheating methods and phosphate.

• 복식문화연구
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• 제29권2호
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• pp.272-288
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• 2021

The purpose of this study is to classify the types of decoration techniques used in women's Chima and Jeogori in traditional Hanbok catalogs from 2010 to 2020, and to analyze the frequency of each type. The method of this study is as follows. This study first investigated the transition of modern Hanbok and decorative techniques by analyzing and classifying such work in previous studies. Based on this, the technique of decorating the Jeogori and Chima that appeared in the traditional Hanbok catalog of the study period was analyzed. The results of the study are as follows. In the case of Jeogori, in the first half of 2010, the decorative technique of a relatively large size was used, and the decorativeness tended to be strong. However, in the late 2010s, the number of decorative techniques used in Jeogori has decreased, and the size of the decorative technique has become smaller and more concise, leading to a tendency to understated decoration. In the case of Chima, techniques to express natural texture by processing threads or fabrics themselves were mainly used rather than techniques to add decoration to the surface, and techniques to express various surface texture tended to develop toward the late 2010s. The change in the decoration technique of Jeogori and Chima appears to be a combination of social, cultural, and economic factors such as a change in consumption culture and a reduction in the wedding market.

• 공업화학
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• 제31권1호
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• pp.67-72
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• 2020

Biomaterials are frequently functionalized with Arg-Gly-Asp (RGD) peptides to provide cell adhesion sites. In this study, RGD peptides were enzymatically coupled on to the surface of fibroin microspheres. Papain exhibited a strong preference for dansyl phenylalanine for the peptide formation with fibroin microspheres. Thus, RGD1 peptide was designed to carry cysteine to both sides of the sequence, glycine as a spacer and two residues of phenylalanine at the C-terminal (CRGDCGFF). The enzymatic modification facilitated by an increasing amount of substrate and by the presence of organic solvent, dimethylsulfoxide at 25% (v/v). Microspheres coupled with RGD1, showed a significantly different precipitation property and an increased apparent volume, possibly due to the steric hindrance of RGD peptides on the surface. Transmission electron microscopy also confirmed the presence of cysteine residues in RGD1 coupled on the surface of microspheres stained with gold nanoparticles. RGD1-microspheres significantly facilitated the growth of murine fibroblast 3T3 cells even under non-adhesion culture conditions.

• BMB Reports
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• 제40권6호
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• pp.1002-1008
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• 2007

PreS domain of Hepatitis B virus (HBV) surface antigen is a good candidate for an effective vaccine as it activates both B and T cells besides binding to hepatocytes. This report deals with overexpression and purification of adr subtype of surface antigen that is more prevalent in Pakistan. PreS region, comprising 119 aa preS1 region plus a 55 aa preS2 region plus 11 aa from the N-terminal S region, was inserted in pET21a+ vector, cloned in E. coli $DH5\alpha$ cells and expressed in E. coli BL21 codon+ cells. The conditions for over expression were optimized using different concentrations of IPTG (0.01-5 mM), and incubating the cells at different temperatures (23-$41^{\circ}C$) for different durations (0-6 h). The cells were grown under the given optimized conditions (0.5 mM IPTG concentration at $37^{\circ}C$ for 4 h), lysed by sonication and the protein was purified by ion exchange chromatography. On the average, 24.5 mg of recombinant protein was purified per liter of culture. The purified protein was later lyophilized and stored at $-80^{\circ}C$.

• 한국물환경학회지
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• 제20권6호
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• pp.597-602
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• 2004

Field experimental study was performed to examine characteristics of nutrient export from paddy rice fields with irrigation practices. Experimental fields with surface-water and ground-water irrigation were monitored and analyzed during rice culture period. The water balance showed that outflow generally balanced the inflow showing that about half (58~68%) of total outflow was lost by surface drainage. Water and nutrient export are more in surface-water irrigation paddy than in ground-water irrigation paddy. The reasons might be more irrigation water available and easy to use in surface-water irrigation. If irrigation water reduced, it could result in reduction of nutrient export in paddy rice fields, which can save water and protect water quality. However, deviation from conventional standard practices might affect the rice yield and further investigations are necessary.

• Design & Manufacturing
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• 제18권3호
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• pp.30-36
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• 2024

As the demand for biomaterials and medical devices increases due to advancements in medical technology and the rising average lifespan of the population, the importance of surface treatment technology for biometallic materials used in orthopedic implants is highlighted. Achieving stable mechanical attachment between the implant and human bone, specifically bone cell adhesion, is crucial. Without proper adhesion, issues such as inflammation and reduced load-bearing capacity can occur, leading to the need for implant reimplantation. Therefore, this paper focuses on creating a micro-groove pattern using a pulsed nanosecond laser on the surface of a titanium alloy (Ti6Al4V), a biometallic material, to promote cell adhesion. To evaluate the effectiveness of the pattern in enhancing cell adhesion, MG-63 osteoblasts were cultured on the micro-groove patterned surface, and their adhesion and morphological changes were analyzed. This study confirms the potential of laser processing as a surface treatment method for biometallic materials.

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 1998년도 가을 학술발표회 프로그램
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• pp.2-4
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• 1998

Proliferation of Nocardia amarae cells in activated sludge has often been associated with the generation of nuisance foams. Despite intense research activities in recent years to examine the causes and control of Nocardia foaming in activated sludge, the foaming continued to persist throughout the activated sludge treatment plants in United States. In addition to causing various operational problems to treatment processes, the presence of Nocardia may have secondary effects on the fate of heavy metals that are not well known. For example, for treatment plants facing more stringent metal removal requirements, potential metal removal by Nocardia cells in foaming activated sludge would be a welcome secondary effect. In contrast, with new viosolid disposal regulations in place (Code o( Federal Regulation No. 503), higher concentration of metals in biosolids from foaming activated sludge could create management problems. The goal of this research was to investigate the metal sorption property of Nocardia amarae cells grown in batch reactors and in chemostat reactors. Specific surface area and metal sorption characteristics of N. amarae cells harvested at various growth stages were compared. Three metals examined in this study were copper, cadmium and nickel. Nocardia amarae strain (SRWTP isolate) used in this study was obtained from the University of California at Berkeley. The pure culture was grown in 4L batch reactor containing mineral salt medium with sodium acetate as the sole carbon source. In order to quantify the sorption of heavy metal ions to N amarae cell surfaces, cells from the batch reactor were harvested, washed, and suspended in 30mL centrifuge tubes. Metal sorption studies were conducted at pH 7.0 and ionlc strength of 10-2M. The sorption Isotherm showed that the cells harvested from the stationary and endogenous growth phase exhibited significantly higher metal sorption capacity than the cells from the exponential phase. The sequence of preferential uptake of metals by N. amarae cells was Cu>Cd>Ni. The specific surFace area of Nocardia cells was determined by a dye adsorption method. N.amarae cells growing at ewponential phase had significantly less specific surface area than that of stationary phase, indicating that the lower metal sorption capacity of Nocardia cells growing at exponential phase may be due to the lower specific surface area. The growth conditions of Nocardia cells in continuous culture affect their cell surface properties, thereby governing the adsorption capacity of heavy metal. The comparison of dye sorption isotherms for Nocardia cells growing at various growth rates revealed that the cell surface area increased with increasing sludge age, indicating that the cell surface area is highly dependent on the steady-state growth rate. The highest specific surface area of 199m21g was obtained from N.amarae cell harvested at 0.33 day-1 of growth rate. This result suggests that growth condition not only alters the structure of Nocardia cell wall but also affects the surface area, thus yielding more binding sites of metal removal. After reaching the steady-state condition at dilution rate, metal adsorption isotherms were used to determine the equilibrium distributions of metals between aqueous and Nocardia cell surfaces. The metal sorption capacity of Nocardia biomass harvested from 0.33 day-1 of growth rate was significantly higher than that of cells harvested from 0.5- and 1-day-1 operation, indicatng that N.amarae cells with a lower growth rate have higher sorpion capacity. This result was in close agreement with the trend observed from the batch study. To evaluate the effect of Nocardia cells on the metal binding capacity of activated sludge, specific surface area and metal sorption capacity of the mixture of Nocardia pure cultures and activated sludge biomass were determined by a series of batch experiments. The higher levels of Nocardia cells in the Nocardia-activated sludge samples resulted in the higher specific surface area, explaining the higher metal sorption sites by the mixed luquor samples containing greater amounts on Nocardia cells. The effect of Nocardia cells on the metal sorption capacity of activated sludge was evaluated by spiking an activated sludge sample with various amounts of pre culture Nocardia cells. The results of the Langmuir isotherm model fitted to the metal sorption by various mixtures of Nocardia and activated sludge indicated that the mixture containing higher Nocardia levels had higher metal adsorption capacity than the mixture containing lower Nocardia levels. At Nocardia levels above 100mg/g VSS, the metal sorption capacity of activate sludge increased proportionally with the amount of Noeardia cells present in the mixed liquor, indicating that the presence of Nocardia may increase the viosorption capacity of activated sludge.

• 고문화
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• 69호
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• pp.63-89
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• 2007

본고는 지금까지 조사된 강원지역의 점토대토기 출토 유적의 양상을 바탕으로 그 상한연대 및 전개과정과 성격을 고찰하였다. 이를 위해 그동안 발굴조사된 유적을 중심으로 입지와 분포, 유구의 규모와 구조, 그리고 출토 유물의 양상을 분석하였다. 강원지역 점토대토기 출토 유적의 양상을 살펴보면 영서지역과 영동지역 간에는 입지 및 유구의 규모와 구조는 차이가 없으나, 점토대토기의 형태 등 출토 유물의 양상에 다소 차이가 있다. 필자는 유구와 유물의 양상에 대한 분석을 바탕으로 강원지역의 점토대토기문화는 영서에서 영동지역으로의 단선적인 전파가 아니라 여러 전파경로를 통해 유입되었을 가능성을 제시하였다. 그리고 유적의 탄소 연대 측정결과를 검토해 보았을 때, 점토대토기문화의 상한연대를 기원전 4세기 후반에서 2세기 전반으로 보고 있는 기존의 연구 결과보다 시기가 앞서고 있으며, 지석묘의 하부구조에서 확인되는 사례도 있어 강원지역의 점토대토기문화는 이전의 지석묘를 축조하던 무문토기문화와 일정 기간동안 병존하였던 것으로 보인다.

• Korean Chemical Engineering Research
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• 제54권1호
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• pp.140-144
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• 2016

본 연구에서는 극지 연구소로부터 분양 받은 Arthrobacter sp. PAMC 27388 균주에서 생산되는 아밀라아제(amylase)를 물리적 요인(physical factor)들의 변화를 통하여 생산배지 최적화를 수행하였다. 한천 배지 상에서 lugol solution을 이용한 클린환의 확인을 통하여 아밀라아제가 생산됨을 확인하였으며, 16S rDNA를 이용하여 동정한 결과 Arthrobacter sp. 임을 확인할 수 있었다. 최적화 이전의 아밀라아제 생산량은 1.66 mU/L로 확인되었다. 최적화 결과, 2.49 mL의 접종부피, pH 6.85, 42.87 mL의 배지 부피의 조건에서 가장 많은 양의 아밀라아제가 생산될 것으로 예상되었으며, 생산량은 2.84 mU/L로 예상되었다. 확인 실험을 통하여 최적화 이전과 비교하여 생산량이 약 150% 증가한 2.50 mU/L의 아밀라아제가 생산됨을 확인할 수 있었다.