• 미생물학회지
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• 제16권1호
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• pp.30-40
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• 1978

Detergent soluble fractions were obtained from T. ferrooxidans ATCC 13598 and the T. thiooxidans ATCC 8085 which were treated with 3% of Tween 20. The detergent soluble antigen(crude antigen) fractions of the T.ferrooxidans and the T.thiooxidans were subjected to hydroxyapatite. In the case of T.thiooxidans, further purification was carried out on the DEAE-cellulose column chromatography. The antigen fractions, such as the hydroxyapatite peak-1(Tf, HA-1) and peak-2 from T.ferrooxidans(Tf. HA-2) and hydroxyapatite peak-1(Tt, HA-1), DEAE-cellulose peak-1(Tt, DP-1) and peak-2(Tt, DP-2) from T. thiooxidans wre compared each other with the homologous and the heterologous and the heterologous antisera against to the Thiobacillus species. The hydroxyapatite peak-2 fraction from the T.ferrooxidans(Tf, HA-2) and DEAE-cellulose peak-2 fraction from the T.thiooxidans(Tt, DP-2) were represented the type-specific immuno-reactivities between the T.ferrooxidans and the T.thiooxidans on the several sets of double gel diffusioin analysis. The type-specific antigen fractions from both of the baceteria were mainly composed of protein with entierly different electrophoretic mobility on the SDS-polyacrylamide gel electrophoresis. However, the PAS positive banding patterns on the electrophorogram showed wide range of common antigenic properties in the T. ferrooxidans and the T.thiooxidans, respectively.

• 한국식품영양과학회지
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• 제32권8호
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• pp.1323-1327
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• 2003

감은 예전부터 민간약으로 종기나 염증질환, 치질에 곶감을 이겨 붙였고 부스럼이나 화상에는 불에 말린 감을 바르면 통증을 멎게 하고 새살을 돋게 하는 효능이 있고 고혈압을 예방하고 동맥경화에 효과가 있는 성분이 있다고 알려져 있다. 사람의 plasma에서 thrombin time(TT)를 사용한 혈액 응고저해 assay를 이용하여 감꼭지에서 혈액응고저해물질을 겔여과크로마토그래피, 소수성크로마토그래피, 음이온교환크로마토그래피, 또 한번의 겔여과크로마토그래피를 통해 정제했다. 감꼭지의 혈액응고저해물질은 분자량이 130,000 ∼ 180,000으로 거대 분자이고 구성분은 C, H, O로 구성되어 있고 periodate oxidation시 거의 활성이 소멸되고 열에 안정하며 주로 glucose와 galactose로 구성된 다당류로 추정된다.

• International Journal of Oral Biology
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• 제40권2호
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• pp.79-83
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• 2015

The purpose of the study was to investigate the antimicrobial activity of the methanol extract of Coptidis rhizome against the type strains of cariogenic bacteria, Streptococcus mutans and Streptococcus sobrinus, and the periodontopathogens, Porphyromonas gingivalis, Prevotella intermedia, Treponema denticola and Aggregatibacter actinomycetemcomitans. The antimicrobial activities of the crude extract and the methanol extract fractions of Coptidis rhizome separated by silica gel chromatography were evaluated by determining the minimal bactericidal concentration (MBC) values, using the microdilution method. The cell viability test of the extracts of Coptidis rhizome on the KB cells was also studied by methyl thiazolyl tetrazolium (MTT) assay. Our results showed that the 11th fraction (F11) of the methanol extract had the greatest antimicrobial activity against the tested bacteria, with no associated cytotoxicity on the KB cells, upto a concentration of $50{\mu}g/ml$. These results suggest that the silica gel chromatography fraction F11 of the methanol extract of Coptidis rhizome, could be useful in the development of oral hygiene products as an antimicrobial agent for the prevention of dental caries and periodontal diseases.

• 접착 및 계면
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• 제12권2호
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• pp.67-72
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• 2011

Acrylic pressure-sensitive adhesives are used in many different parts in the world. But acrylic acid in PSAs may occur unexpected results such as corroding adherends or producing by-products when applied within electronic devices. This study employed acrylic PSAs based on 2-ethylhexyl acrylate (2-EHA), 2-hydroxyethyl acrylate (2-HEA) and butyl acrylate (BA) with different coating thickness. There are two types of curing agents. One is methylaziridine derivative (MAZ) and the other is aluminum acetylacetonate (AlACA). This study examined the adhesion performance and curing behaviors using peel strength, probe tack and gel fraction. Also, the viscoelastic properties of acrylic PSAs were investigated from Advanced rheometric expansion system (ARES).

• 한국염색가공학회:학술대회논문집
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• 한국염색가공학회 2011년도 제45차 학술발표회
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• pp.7-7
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• 2011

Poly(ethylene terephthalate)(PET) is one of the most widely used materials in textile industry. It can have a low cost, silk-like handle, and excellent mechanical properties. Low thermal stability of PET had been a common problem limiting its high temperature application. The polyester have been known to have the disadvantage of degradation under ionized irradiation compared to crosslikable polymers such as polyethylene, polypropylene and polystylene. To improve thermal stability of PET, the PET films were photocrosslinked by UV irradiation. A hydrogen-abstractable photoinitiator was used to photocrosslink of PET by continuous UV irradiation. Photoinitiator addition increased the gel fraction. The photocrosslinking was attributed to the recombination of PET radicals generated upon UV irradiation, which was enhanced by the hydrogen abstraction of the PET polymer chains by the added photoinitiator. Also the crosslinked PET showed higher thermal stability and mechanical strength with increasing UV energy. Polyester type films such as poly(ethylene naphthalate)(PEN) and poly(butylene terephthalte)(PBT) were also increased the gel fraction and improved thermal stability and mechanical properties by UV irradiation.

• 한국염색가공학회지
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• 제24권4호
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• pp.281-287
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• 2012

Poly(phenylene sulfide) films containing acetophenone as a photoinitiator were photocrosslinked under UV irradiation using a continuous UV irradiator. The gel fraction of the irradiated PPS in 1-Chloro naphthalene reached 94.7% with increasing UV energy and the photoinitiator concentration in the film upto $200J/cm^2$ and 12wt% respectively. Solid state $^1C$ NMR analysis suggested that the crosslinking occurred between the phenylene chains in PPS, indicating that the acetophenone may the phenylene hydrogens and subsequently adjacent polymer radicals could be recombined to form the crosslinked structure. The crosslinking improved the thermal behavior of PPS such as loss of $T_g$ and $T_c$, higher melting point and lower melting enthalphy as well as significantly higher peak pyrolysis temperature as much as $63.5^{\circ}C$. Surprisingly the tensile toughness of the most crosslinked PPS increased by 842%, resulting from the substantial enhancements in tensile modulus, strength and strain as much as 76%, 236% and 240% respectively. Also dynamic mechanical measurement indicated that the distance between crosslinks in the crosslinked PPS reached 85.3 g/mol corresponing to a crosslink density of 0.012 mol/g.

• 방사선산업학회지
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• 제5권4호
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• pp.377-382
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• 2011

Poly(vinyl alcohol) (PVA) is an interesting material with good biocompatibility, high elasticity and hydrophilic chacrateristics. In this study, crosslinked hydrogels based on PVA, and poly(acrylic acid) (PAAc) were prepared by gamma-ray irradiation. PVA and PAAc powders were dissolved in deionized water, and then irradiated by a gamma-ray with a radiation dose of 50 kGy to make hydrogels. The hydrogels were then annealed in an oven at $120^{\circ}C$ for 10 min, 30 min and 50 min under nitrogen atmosphere. The properties of a hydrogel such as gel fraction, swelling behavior, thermogravimetric analysis (TGA) and adhesive strength as a function of PAAc content and annealing time were investigated. The gel fraction decreases with decreasing PAAc content and increasing annealing time. The thermal behaviors have shown different patterns according to the annealing time. The adhesive strength increases with increasing PAAc content.

• Archives of Pharmacal Research
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• 제22권2호
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• pp.213-218
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• 1999

The antioxidant activity of Eriobotrya japonica was determined by measuring the radical scavenging effect on DPPH (1,1-diphenyl-2-picrylhydrazyl) radical and lipid peroxidation produced when mouse liver homogenate was exposed to the air at $37^{\circ}C$, using 2-thiobarbituric acid (TBA). The methanol extract and its factions of Eriobotrya japonica leaves showed strong antioxidant activity. The antioxidant activity of EtOAc and n-BuOH soluble fractions were stronger than the others, and were further purified by repeated silica gel, MCl gel CHP-20P, and Sephadex LH-20 column chromatography. Antioxidant chlorogenic acid, quercetin-3-sambubioside from n-BuOH fraction and methyl chlorogenate, kaempferol- and quercetin-3-rhamnosides, together with the inactive ursolic acid and$ 2{\alpha}$-hydroxyursolic acid from EtOAc fraction were isolated. Antioxidant flavonoids and chlorogenic acid also showed prominent inhibitory activity against free radical generation in dichlorofluorescein (DCF) method.

• 한국식품과학회지
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• 제20권6호
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• pp.883-889
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• 1988

신선한 젓새우(Acetes japonicus)를 재료로 하여 상법에 의해 젓갈을 담근후 실온에서 3개월간 숙성시켰다. 숙성 도중 어육단백질의 특성 변화를 검토해 본 결과, 가용성 단백질의 추출율은 숙성 초기보다 1개월 숙성품이 다소 떨어지나 그 이후는 점차 증가되었다. 10% TCA 가용성 획분은 숙성 1개월 이후 서서히 증가되며 총 가용성단백질에 대한 백분율도 점차 증대되었다. Sephadex G-100에 의한 gel 여과 pattern은 숙성 초기의 것은 6개의 크고 작은 peak를 나타내고 있으나 숙성 1개월 이후에는 뒷쪽의 peak 4개는 사라지고 다시 숙성기간이 흐름에 따라 남은 두 peak중 앞쪽의 것은 점차 편만해지는 경향을, 그리고 뒤의 것은 다시 두개의 peak로 분해되면서 유출속도가 늦어지는 경향을 나타내었다. Polyacrylamide gel 전기영동의 pattern은 숙성 초기의 것은 2개의 뚜렷한 band와 4개의 희미한 band를 나타내었으나 숙성 1개월 이후부터는 뚜렷했던 band들이 가느다란 band들로 포개어져 분산되는 현상을 나타내었다. 이들 band들은 숙성기간이 흐름에 따라 더욱 희미해지는 경향을 나타내었다. 총 유리아미노산의 함량은 숙성 1개월에는 감소되었다가 그 이후에는 다시 증가되었으며 유리아미노산/가용성 단백질의 비는 숙성 도중 계속 증대되다가 숙성 8개월에 다소 감소되는 경향을 나타내었으나 유리아미노산/10% TCA 가용성 획분의 비는 숙성기간중 계속 감소되는 경향을 나타내었다. 숙성기간중 대부분의 유리아미노산 함량은 숙성 1개월에 급격히 증가되어 2배 정도에 이르렀으나 histidine과 arginine은 숙성 1개월에 급격히 감소되었다. 새우젓에 많은 함량을 가지고 있는 glycine과 arginine은 숙성기간중 조성 변화가 일정하지 않았다. 암모니아 함량은 숙성 1개월 이후에 현저히 증가되었다. 젓갈의 pH도 숙성기간중 서서히 증가되었다.

• 한국식품과학회지
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• 제30권4호
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• pp.848-854
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• 1998

멸치어유로부터 EPA와 DHA가 농축된 분획을 제조할 목적으로, 흡착제, 보조용매, 추출압력을 달리하여 초임계 이산화탄소로 추출 분획한 후 추출수율과 지방산 조성을 측정하였다. 추출수율은 흡착제를 사용하지 않은 경우 추출시간의 증가에 따라 급격히 증가하여, 추출 3시간 후에는 63%였지만, 흡착제로 실리카겔과 질산은을 코팅한 실리카겔을 사용한 경우는 완만하게 증가하여 각각 26%와 33%였다. 어유를 질산은으로 코팅한 실리카겔과 혼합하여 추출하였을 때 추출잔류물 분획에 고도불포화지방산들이 농축되었다. 어유를 실리카겔과 혼합하여 초임계 이산화탄소에 보조용매로 hexane, ethyl acetate, ethanol과 함께 추출하였을 때 추출 2시간 후 추출수율은 각각 53.1, 86.3, 88.5%로 초임계 이산화탄소만으로 추출하였을때인 20.0%에 비하여 $2.7{\sim}4.4$배 증가하였다. 보조용매로 ethyl acetate를 사용하였을 때 추출잔류물 분획에서의 EPA와 DHA의 농도가 가장 높았다. 어유를 질산은이 코팅된 실리카겔과 혼합하여 초임계 이산화탄소에 보조용매로 ethyl acetate와 함께 추출하였을 때 추출 3시간 후 추출수율은 207, 276, 345 bar에서 각각 67.3, 76.4, 67.1%로 초임계 이산화탄소만을 사용하였을 때인 33.1%보다 2배 이상 증가하였다. 추출물 분획들의 지방산 조성은 원료 어유에 비하여 모든 추출압력 조건에서 $C14{\sim}C18$의 농도는 증가하였고, EPA와DHA 농도는 큰 폭으로 감소하였다. 추출압력 276 bar에서 추출잔류물 분획의 EPA와 DHA 농도는 각각 28.2%와 38.3%로 원료 어유에 비하여 각각 212%와 236% 농축되었다.