Inactivation of Bacteria in Seawater by Low-Amperage Electric Current

Seawater used in mariculture has been suspected of being a potential source of infection. In this study, the lethal effects of low-amperage electric treatment on microorganisms were examined in natural seawater and in seawater inoculated with Vibrio parahaemolyticus. In both cases, bacteria including V. parahaemolyticus in seawater were completely eliminated in 100 ms by a 0.5-A, 12-V direct current. Electron microscopic investigation of the electrically treated bacteria revealed substantial structural damage at the cellular level. In conclusion, our results indicate that low-amperage electric treatment is effective for rapid inactivation of microorganisms in seawater.ope

戰國時代 楚國 統治體制 硏究 : `縣邑`支配體制의 展開와 楚文化

학위논문(박사)--서울대학교 대학원 :동양사학과,2000.Docto

C-대수의 팽장성질에 대한 개요

Thesis (master`s)--서울대학교 대학원 :수학과,1995.Maste

The Joseon Dynasty Liturgy Dictionary Publication Project and Effective Application of PC

1. 2005년 9월부터 2008년 8월까지 한국학술진흥재단의 지원으로 진행되는 『조선시대 국가전례사전』 편찬 사업은 예교 국가의 중핵인 국가전례를 가장 기초적ㆍ표준적 공구서인 사전으로 정리해야 하기 때문에, 서술 내용의 우수성ㆍ정확성ㆍ통일성 등이 강력하게 요구되는 난이도 높은 작업이다. 이에 따라 『국가전례사전』 팀에서는 지난 2년 동안 PC의 상용 프로그램인 MS 엑셀과 한/글을 응용한 표제어 입력ㆍ분류 매크로, 표제어 서술 Template, 한자 사전, 키 매크로, 상용구, 빠른 교정 등을 자체 제작하여 활용함으로써, 작업의 효율성을 높이고 작업 결과물의 정확성ㆍ통일성 등도 제고하였다. 2-1. 표제어 선정과 입력을 위한 MS 엑셀 매크로: MS Excel 기반의 표제어 입력 매크로를 자체 제작하여 총 8780단어의 표제어들을 효과적으로 선정ㆍ입력하였다. 2-2. 표제어 분류와 정리를 위한 MS 엑셀 정렬ㆍ편집 매크로: 8780 표제어는 연구원들의 검토와 논의를 거쳐 24범주로 분류되었으며, 이를 위해 표제어 분류와 정리를 신속ㆍ간편하게 처리할 수 있는 정렬ㆍ편집 매크로를 자체 제작하여 활용하였다. ① 標目 1148단어 ② 車馬 157단어 ③ 建築 675단어 ④ 官署 231단어 ⑤ 官職 1067단어 ⑥ 軍陣 111단어 ⑦ 器皿 289단어 ⑧ 陵園 126단어 ⑨ 圖書 206단어 ⑩ 排班 285단어 ⑪ 兵甲 165단어 ⑫ 服飾 715단어 ⑬ 山川 40단어 ⑭ 喪葬 361단어 ⑮ 神靈 116단어 ⑯ 神位 70단어 ⑰ 樂舞 607단어 ⑱ 飮食 234단어 ⑲ 儀仗 560단어 ⑳ 儀節 2358단어 21 制度 179단어 22 陳設 368단어 23 冊寶 68단어 24 기타 503단어..

Sterilization of Escherichia coli and MRSA using microwave-induced argon plasma at atmospheric pressure

The use of microwave plasma for sterilization is a relatively new method. The advantages of this method include relatively low temperature, time-saving and nontoxicity compared to the known techniques, such as dry heat, steam autoclave and ethylene oxide (EtO) gas. The aim of this study was to investigate the sterilization effects on Escherichia coli and methicillin-resistant Staphylococcus aureus (MRSA) using self-designed, low-cost and reliable, 2.45 GHz, wave guide-based applicator to generate microwave plasma at atmospheric pressure. The results of this study confirmed that the sterilization effect of microwave-induced argon plasma at atmospheric pressure was caused by free radicals and UV light generated during the plasma treatment and the etching process. The microwave plasma system used in this study required much less exposure time than the previous study on bacterial strains of E. coli and MRSA, because of the high plasma density, the large number of free radicals, and the strong UV intensity.restrictio

Sterilization using microwave-induced argon plasma system at atmospheric pressure

The use of microwaveplasma for sterilization is relatively new. The advantages of this method are the relatively low temperature, time-savings and its nontoxic nature, in contrast to traditional methods such as heat and gas treatment, and radiation. This study investigated the sterilization effects of microwave-induced argon plasma at atmospheric pressure on materials contaminated with various microorganisms, such as bacteria and fungi. A low-cost and reliable 2.45 GHz, waveguide-based applicator was designed to generate microwaveplasma at atmospheric pressure. This system consisted of a 1 kW magnetron power supply, a WR-284 copper waveguide, an applicator including a tuning section, and a nozzle section. Six bacterial and fungal strains were used for the sterilization test. The results showed that regardless of the strain, all the bacteria used in this study were fully sterilized within 20 seconds and all the fungi were sterilized within 1 second. These results show that this sterilization method is easy to use, requires significantly less time than the other traditional methods and established plasma sterilization methods, and it is nontoxic. It can be used in the field of sterilization in medical and dental clinics as well as in laboratory settings.ope

Detection of oleic acid biodegradation by fungi

To investigate oleic acid biodegradation, 47 fungal strains were tested with modified Czapek Dox broth media containing oleic acid, and their biodegradative activities were assayed by measuring the release of [14C]CO2 from the 14C-labeled oleic acid. After 72 h of cultivation, Aspergillus flavus, Aspergillus ochraceus, and Alternaria species metabolized approximately 25% to 35% of the supplied oleic acid. The relationship between the fungal degradation of oleic acid and the fungal growth was also examined using 7 strains of Aspergillus niger. A. niger YMC 0100 and YMC 0322 degraded about 26% of the oleic acid after 72 h, while their germination ratios were more than 30%.ope

Plasma surface modification of poly (d,l-lactic-co-glycolic acid) (65/35) film for tissue engineering

Plasma technique can easily be used to introduce desired functional groups or chains onto the surface of materials, so it has a special application to improve the cell affinity of scaffolds. Additionally, it has been demonstrated that plasma treatment is a unique and powerful method for modifying polymeric materials without altering their bulk properties. Cell affinity is the most important factor to be considered when biodegradable polymeric materials such as poly (d,l-lactic-co-glycolic acid) (PLGA) are utilized as a cell scaffold in tissue engineering. In this study, PLGA surface was modified with TiO2 using magnetron sputtering in order to improve PLGA surface/cells interaction. The changes of surface properties have been characterized by contact angle measurement and X-ray photoelectron spectroscopy (XPS). To confirm the attachment or proliferation of human dermal fibroblasts and rat cortical neural cells, MTT assay and scanning electron microscopy (SEM) were carried out. The results indicated that TiO2-coated PLGA film became hydrophilic and enhanced cell affinity and/or proliferation. It has been suggested that TiO2-coated PLGA matrix can be a candidate for cell scaffolds in tissue engineering.restrictio

Effective screening media for biodegradation of oleic acid by Aspergillus niger

To investigate oleic acid biodegradation, 7 strains of Aspergillus niger were tested with 3 different types of Czapex-Dox broth (CzDB) medium containing oleic acid, and their metabolic abilities to decompose the fatty acid into carbon dioxide and water were compared. When the fungal strains were grown in the CzDB media with both 14C-labeled and non-labeled oleic acid, A. niger YMC 0100 and YMC 0322 oxidized more than 58% of the supplied substrate within 72 h. The addition of saccharose as an additional carbon source substantially reduced the biodegradation of oleic acid to the point that all the strains showed less than 4% degradation.ope

Enhanced neurite outgrowth of rat neural cortical cells on surface-modified films of poly(lactic-co-glycolic acid)

Neural cortical cells, isolated from prenatal rat cerebra, were grown on surface-modified poly(lactic-co-glycolic acid, 65:35) (PLGA) films coated with poly-D-lysine (PDL) with either laminin (LN), fibronectin (FN) or collagen (CN). Immunocytochemistry showed that the isolated cells were highly immunopositive for both neurofilament and MAP-2 with well-organized neurites and somatodendritic localization. The presence of PDL with LN or FN on the PLGA films was essential for increased neural cell growth. Also, PLGA films coated with either PDL/LN or PDL/FN mixtures had higher neurite outgrowth and regular differentiation.restrictio