• Journal of dental hygiene science
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• v.3 no.1
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• pp.11-14
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• 2003

A methylotrophic Actinomycetes strain, which produce the anti-oral cancer activity compound, was isolated from soil and estimated as Amylocolatosis sp. based on taxonomic studies. A methanol didn't have influence on the production of the anticancer compounds. These compound were isolated by ethylacetate extract, silica gel column chromatography, sephadex LH-20 column and reverse phase HPLC. The compounds were very stable under heat ($121^{\circ}C$), acid(pH 2.0) and alkali(pH 11.0) treatment. The cytotoxic effect of isolated anticancer compounds on various cancer cell lines such as A549, SNU-1, KB, L1210, and Sarcoma 180 was investigated by MTT assay method. And these produced compounds also showed the broad antimicrobial spectrum to test strains such as bacteria and yeast.

• Journal of Ocean Engineering and Technology
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• v.23 no.5
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• pp.85-91
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• 2009

A stainless steel that contains aggressive negative ion was known to decrease the corrosion resistance. Stainless steel with super corrosion resistance was developed for improvement of corrosion resistance. Super duplex stainless steel is widely used under sever environment because of good mechanical properties and corrosion resistance. Also, Super duplex stainless steel has long life in severe environments by showing the enough strength and corrosion resistance. But duplex stainless steel is not stabilized compared to austenite stainless steel in corrosion resistance. In this study, corrosion characteristic were investigated to super duplex stainless steel with additive 0.2% nitrogen with $SiO_2$ thin films coated or no coated by sol-gel method in 3.5% NaCl. From test results, corrosion current density in the heat-treated specimen for ${\sigma}$ phase precipitation was higher than that of different heat-treated specimen. Also, $SiO_2$ colloidal-coated specimen had not occurred almost corrosion.

• Journal of Microbiology and Biotechnology
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• v.26 no.12
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• pp.2098-2105
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• 2016

Massive reserves of methane ($CH_4$) remain unexplored as a feedstock for the production of liquid fuels and chemicals, mainly because of the lack of economically suitable and sustainable strategies for selective oxidation of $CH_4$ to methanol. The present study demonstrates the bioconversion of $CH_4$ to methanol mediated by Type I methanotrophs, such as Methylomicrobium album and Methylomicrobium alcaliphilum. Furthermore, immobilization of a Type II methanotroph, Methylosinus sporium, was carried out using different encapsulation methods, employing sodium-alginate (Na-alginate) and silica gel. The encapsulated cells demonstrated higher stability for methanol production. The optimal pH, temperature, and agitation rate were determined to be pH 7.0, $30^{\circ}C$, and 175 rpm, respectively, using inoculum (1.5 mg of dry cell mass/ml) and 20% of $CH_4$ as a feed. Under these conditions, maximum methanol production (3.43 and 3.73 mM) by the encapsulated cells was recorded. Even after six cycles of reuse, the Na-alginate and silica gel encapsulated cells retained 61.8% and 51.6% of their initial efficiency for methanol production, respectively, in comparison with the efficiency of 11.5% observed in the case of free cells. These results suggest that encapsulation of methanotrophs is a promising approach to improve the stability of methanol production.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.302-302
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• 2009

유기농업에서 유기물은 양분의 공급, 토양의 이화학성 개선, 토양의 생물학적 건전성 유지 등 중요한 역할을 한다. 토양의 생물학적 건전성은 토양의 생태계적 기능을 지속적으로 유지시키는 토양미생물이 관여하고 있다. 따라서 본 연구는 유기물의 장기연용에 따른 밭토양 미생물의 다양성을 비교 분석하였다. 여러 가지 유기자원을 동일한 기준으로 매년 동일 장소에 처리하였다. 사용된 유기자원은 가축분퇴비, 채종유박인 유기질비료, 볏짚으로만 퇴비화한 볏짚퇴비와 겨울철 휴한기에 헤어리베치를 재배하여 이듬해 봄에 예취한 후 토양에 환원한 녹비처리구, NPK구, 가축분퇴비를 혼용처리한 NPK퇴비군, 양분을 전혀 시용하지 않은 무비구 등 총 7처리구였다. 각각의 처리구에서 토양(0-20 cm)을 채취하여 배양성 토양미생물은 희석평판법으로 해당 선백배지에 시료를 도말 하여 조사하였고 비배양성 미생물은 토양으로부터 genomic DNA를 추출하여 세균의 16S rDNA를 증폭시킨 후 denaturing gradient gel electrophoresis (DGGE)를 수행하여 분석하였다. 주요결과를 요약하면 밭토양에 서식하는 토양미생물의 균수는 처리별간의 차이를 보였으며 유기물처리구가 화학비료처리구보다 높았다. DGGE 분석을 통해 유기물 처리에 따른 군집의 다양성을 살펴본 결과 Fig. 1에서 보는바와 같이 Gel 상에서 다양한 위치의 밴드를 확인할 수 있었고 처리별로 특이 밴드가 있음을 확인할 수 있었다. Fig. 1에서 얻은 DGGE profile상의 밴드 강도와 수를 비교하여 Fig 2와 같은 dendrogram을 나타낼 수 있었다.

• Applied Chemistry for Engineering
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• v.21 no.5
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• pp.564-569
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• 2010

Highly anti-reflective optical property has been focussed in the field of thin film and display because of increasing demands to the high transparency and clearness of optical component. In this study, to obtain anti-reflective property, the formation of aluminium oxide with nanoscaled flowerlike frame structure was introduced as oxide material monolayer on the substrate by hydrothermal synthesis through sol-gel method. The properties of coating layer were measured by the means of UV-Vis spectroscopy, FT-IR spectroscopy, XRD, and FE-SEM. The morphology of coating layer in alumina-sol coated samples was controlled by hydrothermal temperature and time with aid of ultrasound. It was found that high transparency and anti-reflective optical properties were obtained the formation of flowerlike nanoframe structure.

• Korean Journal of Food Science and Technology
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• v.19 no.2
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• pp.102-106
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• 1987

In order to examine the appropriateness of types of pigskin as a raw material for gelatin production, comparison was made on the quality of gelatins made from raw and scalded pigskins. Raw and scalded pigskins were acidified in 1.7% HCl solution for 15-18 hr and then washed by tap water for 10 hr. After washing, pigskins were extracted at $60^{\circ}C$, $70^{\circ}C$ and $80^{\circ}C$ to produce gelatins. Gelatins from raw pigskins appeared to be better in gel strength than those from scalded ones at all extraction temperatures. Gelatin yield was higher with raw than with scalded pigskins. With the increase of extraction temperature, the decrease in gel strength and viscosity was resulted in. More colored gelatins were produced with increasing extraction temperature in both raw materials. Electrophoretic pattern of gelatins showed that higher molecular weight fractions decreased with the increase of extraction temperature and pigskin gelatin had more complicated molecular composition than that of type B gelatin (alkali-treated gelatin).

• Applied Science and Convergence Technology
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• v.25 no.1
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• pp.19-24
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• 2016

In this study, we evaluated the change of electronic structure during redox process in cerium-doped $ZrO_2$ grown by sol gel method. By sol-gel method, we could obtain cerium-doped $ZrO_2$ in high oxygen partial pressure and low temperature. After post annealing process in nitrogen ambient, the film is deoxidized. We used spectroscopic and theoretical methods to analysis change of electronic structure. X-ray absorption spectroscopy (XAS) for O K1-edge and Density Functional Theory (DFT) calculation using VASP code were performed to verify the electronic structure of the film. Also, high resolution x-ray photoelectron spectroscopy (HRXPS) for Ce 3d was carried out to confirm chemical bond of cerium doped $ZrO_2$. Through the investigation of the electronic structure, we verified as followings. (1) During reduction process, binding energy of oxygen is increase. Simultaneously, oxidation state of cerium was change to 4+ to 3+. (2) Cerium 4+ and cerium 3+ states were generated at different energy level. (3) Absorption states in O K edge were mainly originated by Ce 4+ $f_0$ and Ce 3+, while occupied states in valance band were mainly originated from Ce 4+ $f_2$.

• Journal of Life Science
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• v.20 no.11
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• pp.1656-1661
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• 2010

Alkaline protease for the hydrolysis of egg yolk protein was immobilized on five carriers - Duolite A568, Celite R640, Dowex-1, Dowex 50W and Silica gel R60. Duolite A568 showed a maximum immobilization yield of 24.7%. Optimum pH for the free and immobilized enzyme was pH 8 and 9, respectively. However, no change was observed in optimum temperature ($50^{\circ}C$). Thermal stability was observed in immobilized enzymes compared to free enzymes. The immobilized enzyme retained 86% activity after 10 cycle operations in a repeated batch process. The effect of flow rate on the stability of enzyme activity in continuous packed-bed reactor was investigated. Lowering flow rate increased the stability of the immobilized enzyme. After 96 hr of continuous operation in a packed-bed reactor, the immobilized enzyme retained 83 and 61% activity when casein and egg yolk were used as a raw materials, respectively.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.35 no.3
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• pp.146-152
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• 2009

Traditional surgical method or injection using filler is performed for soft tissue augmentation. Surgical methods have disadvantage of surgical morbidity. Commercially available injectable materials have the disadvantages such as resorption, short-term effect. repeated application and hypersensitivity. Significant shortcoming of cell therapy using autologous fibroblasts is delay of treatment effect. Chitosan/${\beta}$-glycerol phosphate (GP) solution has thermosensitive property and allows sol-gel transition at physiologic pH and temperature. These properties may resolve the delay of treatment effect. The purposes of this study are to evaluate the viscosity and pH changes of chitosan/${\beta}$-GP solutions and to evaluate the effect of chitosan/${\beta}$-GP solution on fibroblast proliferation and production of collagen. We measured the viscosity and pH as function of temperature, of the solution containing 1:0.7, 1:0.75, 1:0.8 chitosan (1, 10, 100, 700 kDa) /${\beta}$-GP. Fibroblasts from ears of 5 rats were cultured in chitosan/${\beta}$-GP solutions for 3 weeks. Cell proliferation and collagen contents were measured every week with WST (water-soluble tetrazolium salt) assay and Collagen assay respectively. The Results are 1) Chitosan(100 kDa<)/${\beta}$-GP solution (1:0.75) showed sol-gel transition at physiologic pH and body temperature and injectable properties. It will enable to resolve the delay in treatment effect 2) Cell proliferation and total collagen contents of the control group were increased with time. However, these decreased after the 1st week in experimental group 3) Collagen contents in the experimental group are higher than that of control group. Chitosan/${\beta}$-GP solution may provide favorable conditions for cell function

• Korean Chemical Engineering Research
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• v.40 no.6
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• pp.735-740
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• 2002

In order to improve the anti-fogging property of polymer films, organic-inorganic hybrid coating solutions which have good hydrophilic property and transmission in the range of visible light were synthesized by the sol-gel method. The coating solutions were prepared by adding glycidoxypropyl trimethoxysilane(GPS) to a colloidal silica(15 nm) suspension(Ludox). GPS as silane coupling agent forms strong bonds to the colloidal silica and surrounding polymer matrix and links two different materials together. Solutions prepared by addition of GPS at the acidic condition resulted in coatings that were less prone to cracking, while those at the basic condition caused coatings with more cracking. These resulted in better hydrophilic property and transmission in the range of visible light for the solution prepared at the acidic condition(pH 2). Compared with coatings under acidic conditions, coatings prepared at basic conditions showed worse hydrophilic property and transmission in the range of visible light.