• 한국세라믹학회지
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• 제47권6호
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• pp.618-622
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• 2010

Cost-effective purification methods of silicon were carried out in order to replace the conventional Siemens method for solar grade silicon. Firstly, acid leaching which is a hydrometallurgical process was preceded with grinded silicon powders of metallurgical grade (~99% purity) to remove metallic impurities. Then, plasma treatments were performed with the leached silicon powders of 99.94% purity by argon plasma at 30 kW power under atmospheric pressure. Plasma treatment was specifically efficient for removing Zr, Y, and P but not for Al and B. Another purification step by EB treatment was also studied for the 99.92% silicon lump which resulted in the fast removal of boron and aluminum. That means the two methods are effective alternative tools for removing the doping elements like boron and phosphor.

• 한국수소및신에너지학회논문집
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• 제27권2호
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• pp.135-143
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• 2016

Biogas is a renewable fuel from anaerobic digestion of organic matters such as sewage sludge, manure and food waste. Raw biogas consists mainly of methane, carbon dioxide, hydrogen sulfide, and water. Biogas may also contain other impurities such as siloxanes, halogenated hydrocarbons, aromatic hydrocarbons. Efficient power technologies such as fuel cell demand ultra-low concentration of containments in the biogas feed, imposing stringent requirements on fuel purification technology. Biogas is upgraded from pressure swing adsorption after biogas purification process which consists of water, $H_2S$ and siloxane removal. A polymer electrolyte membrane fuel cell power plant is designed to operate on reformate produced from upgraded biogas by steam reformer.

• 약학회지
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• 제29권1호
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• pp.50-54
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• 1985

Seven different sorbents were evaluated for their adsorptivity and desorptivity of antibiotic, chloramphenicol. Among the sorbents studied, Carbopak B was found to be the most efficient in enriching the chloramphenicol from dilute aqueous solution. Interfering components in the milk matrix could be washed off by water and petroleum ether from Carbopak B column, while the chloramphenicol was retained on the surface of Carbopak B. The method of simple and efficient purification and enrichment of chloramphenicol using Carbopak B, followed by quantitative analysis employing $C_{18}$ reversed phase high performance liquid chromatography has been applied to the determination of chloramphenicol in milk.

• 한국식품과학회지
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• 제20권6호
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• pp.780-786
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• 1988

본 실험은 Staphylococcus aureus로부터 생성되는 enterotoxin A의 분리를 위하여 각종 분리방법을 조사하였고 그 특성들을 상호 비교하였던 바 다음과 같은 결과를 얻었다. Amberlite 수지는 배지로부터 처음 toxin을 분리 하는 데에는 간편한 수지이나 정제도에 있어서는 약 70%수준으로 다른 방법들에 비해 낮은 편이었다. CM-cellu-lose수지는 0.2M phosphate buffer로 용출했을 때 75% 정도의 정제도를 가진 toxin을 분리할 수 있었으나 stepwise법으로 용출했을 때에는 80% 이상으로 정제도를 높일 수 있었고 Amberlite 수지와 함께 사용했을 때에는 90%정도의 toxin을 얻을 수 있었다. Amberlite나 CM-cellulose수지로 정제한 후 gel filtration을 실시하면 정제도를 더 높일 수 있었다. FPLC는 분리도와 정제도에서 가장 우수하였으며 FPLC의 결과에 따라 Amberlite 수지는 toxin 분획을 중심으로 앞의 분획을 그리고 CM-cellulose 수지는 뒤의 분획을 주로 제거 하는 특징을 가진다. 따라서 위의 column중 하나만 사용한 후 FPLC를 사용하면 95%이상의 toxin을 분리하는 것이 가능하였다.

• Journal of Microbiology and Biotechnology
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• 제19권7호
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• pp.727-733
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• 2009

Heat shock protein 70 kDa (hsp70), a molecular chaperone involved in folding of nascent proteins, has been studied for its ability to activate innate and specific immunity. High purity hsp70 preparation is generally required for immunization experiments, because endotoxins and other immunologically active contaminants may affect immune responses independently of hsp70. We have developed a novel modification of E. coli-expression medium that enabled a simple two-step production and purification method for endotoxin-free recombinant hsp70. During Ni-NTA-based affinity purification of hsp70, a contaminating protein from host E. coli cells, L-glutamine-n-fructose-6-phosphate aminotransferase (GFAT), was identified. By testing various compounds, supplementation of growth medium with a GFAT metabolite,N-acetylglucosamine, was found to reduce GFAT expression and increase the total hsp70 yield five times. The new protocol is based on column purification of His-tagged hsp70 protein produced by E. coli with the modified medium, followed by endotoxin removal by Triton X-114 extraction. This approach yielded hsp70 with high purity and minimal endotoxin contamination, making the final product acceptable for immunization experiments. In summary, a simple modification of growth medium allowed production of recombinant mouse hsp70 in high yield and purity, thus compatible with immunological studies. This protocol may be useful for production of other Histagged proteins expressed in E. coli.

• 유기물자원화
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• 제8권4호
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• pp.153-159
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• 2000

본 연구는 소각재 주체의 준호기성 매립지를 대상으로 폐기물 매립지가 보유하고 있는 오염물질에 대한 정화능력을 최대한 활용할 수 있는 조기안정화 매립공법을 개발하기 위한 기초적 연구로, 대형 모의 매립실험을 약 4년간 실시하여 폐기물 매립고의 차이에 따른 오염물질의 정화능을 평가하여 다음과 같은 결론을 얻었다. TOC 성분은 폐기물 매립고가 증가할 수록 매립지내에서의 분해량이 많아지는 것으로 나타났으며, T-N의 경우에는 매립고 6m까지는 매립고가 증가할수록 폐기물의 분해능이 향상되는 것으로 나타났으나, 6m 이상부터는 매립고의 증가와는 무관한 것으로 나타났다. 따라서 모의 매립조 내부에서의 TOC와 T-N 성분의 물질수지를 평가할 때 폐기물 매립고가 6m정도 일때 오염물질에 대한 정화능이 가장 뛰어난 것으로 평가되었다.

• 한국수정란이식학회지
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• 제33권4호
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• pp.327-336
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• 2018

To date, there are no protocols optimized to the effective separation of spermatogonial stem cells (SSCs) from testicular cells derived from mouse testes, thus hindering studies based on mouse SSCs. In this study, we aimed to determine the most efficient purification method for the isolation of SSCs from mouse testes among previously described techniques. Isolation of SSCs from testicular cells derived from mouse testes was conducted using four different techniques: differential plating (DP), magnetic-activated cell sorting (MACS) post-DP, MACS, and positive and negative selection double MACS. DP was performed for 1, 2, 4, 8, or 16 h, and MACS was performed using EpCAM ($MACS^{EpCAM}$), Thy1 ($MACS^{Thy1}$), or GFR ${\alpha}1$ ($MACS^{GFR{\alpha}1}$) antibodies. The purification efficiency of each method was analyzed by measuring the percentage of cells that stained positively for alkaline phosphatase. DP for 8 h, $MACS^{Thy1}$ post-DP for 8 h, $MACS^{GFR{\alpha}1}$, positive selection double $MACS^{GFR{\alpha}1/EpCAM}$, and negative selection double $MACS^{GFR{\alpha}1/{\alpha}-SMA}$ were identified as the optimal protocols for isolation of SSCs from mouse testicular cells. Comparison of the purification efficiencies of the optimized isolation protocols showed that, numerically, the highest purification efficiency was obtained using $MACS^{GFR{\alpha}1}$. Overall, our results indicate that $MACS^{GFR{\alpha}1}$ is an appropriate purification technique for the isolation of SSCs from mouse testicular cells.

• Mass Spectrometry Letters
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• 제10권2호
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• pp.66-70
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• 2019

Rivaroxaban (RRN) is the first available active direct factor Xa inhibitor (anticoagulant) with oral administration. Due to its success in market, there have been efforts to develop various RRN formulations, and the development of good analytical methods for its in vivo evaluation is an essential prerequisite. Thus, here, a simple and efficient method to determine RRN in rat plasma using liquid-liquid extraction (LLE) and liquid chromatography and multiple reaction monitoring (LC-MRM) was presented. The use of ethyl acetate as the LLE solvent results appropriate extraction and purification of RRN and it also helps the significant reduction of rat plasma volume required for RRN quantitation. The developed method showed good analytical performance including specificity, linearity ($r^2{\geq}0.999$ within 0.5 - 500 ng/mL), sensitivity (the lower limit of quantitation at 0.5 ng/mL), accuracy (89.3 - 107.0%), precision (${\geq}12.7%$), and recovery (89.2 - 105.7%). Additionally, RRN in sample extracts showed good stability. Finally, the applicability of the validated method to the PK evaluation of RRN was confirmed after its oral administration to normal rats. The present method is the first analytical method employing LLE for the simple and efficient extraction and purification of RRN in rat plasma. Therefore, the present method can contribute to the development of new RRN formulations as well as to the monitoring of RRN in special clinical situations through its efficient determination in various samples with or without minor modification.

• 생명과학회지
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• 제19권5호
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• pp.561-565
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• 2009

인간조직인자는 혈액응고인자 factor VII 과 복합체를 형성하며 연속적인 혈액응고 연쇄반응을 촉매하는 효소 활성체이다. 복합체 형성에 필수적인 이 조직인자의 세포 외 부분이, 기존의 융합 단백질 및 히스티딘 말단이 없는 새로운 발현 벡터에 의해 대장균 내에서 과량 발현 되었다. 봉입체 형태로 발현된 재조합 인간조직인자는 DEAE-Sephacel 크로마토그라피 기술을 적용하여 분리, 정제 및 구조적 복원이 동시에 시도 되었다. 정제된 재조합 단백질은 SDS-PAGE 분석에서 순수한 형태로 나타났으며, 생물학적 활성도 또한 기존의 조직인자와 거의 동등함을 보였다. 본 연구의 발현 및 정제 시스템은 이전의 보고에서 보여진 방법들에 비해 단백질 분해효소를 사용하지 않아 추가적인 크로마토그라피 과정이 필요 없어 좀 더 효율적이기 때문에 기존의 발현 시스템에 대해 대체할 수 있는 매우 유용한 방법으로 제공된다.

• 한국수산과학회지
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• 제48권3호
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• pp.301-307
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• 2015

Phlorotannins and marine algal polyphenols, including dieckol, 6,6-bieckol, phloroglucinol, phlorofucofuroeckol-A, and eckol, were isolated from brown seaweeds. These compounds have beneficial bioactivities, and Ecklonia cava has become widely used for the extraction and isolation of phlorotannins. Eckol, in particular, has been to shown to have antioxidant, anti-inflammatory, anticoagulatory, and photoprotective properties. However, due to its low abundance in weaweed, the isolation and purification of eckol are difficult. Its limited availability renders the isolation and purification of eckol labor-intensive processes. Centrifugal partition chromatography (CPC) is an efficient technique for the isolation and purification of eckol. In this study, eckol was isolated from the ethyl acetate fraction of the 70% ethanol extract of E. cava using CPC with a two-phase solvent system of a n-hexane:EtOAc:methanol:water (2:8:3:7, v/v) solution. The purity and anti-inflammatory activity of the isolated eckol were verified by high-performance liquid chromatography and by assaying lipopolysaccharide-induced inflammatory responses in an immortalized murine BV2 microglial cell line, respectively. In conclusion, CPC is a useful technique for simple and efficient isolation of eckol from E. cava.