• 제목/요약/키워드: DO

검색결과 63,307건 처리시간 0.069초

Clearance of False-positive Antigen-Antibody Reactions of a Diagnostic Antigen Production in Escherichia coli with Human Sera

  • Noh, Kap-Soo;Kim, Jong-Wan;Ha, Suk-Hoon;Yoo, Wang-Don;Jeon, Weong-Joong;Kim, Hyun-Su
    • Biotechnology and Bioprocess Engineering:BBE
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    • 제4권1호
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    • pp.63-65
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    • 1999
  • Although many pharmaceutically useful proteins are produced in E. coli expression system, it is very are rare for the system to be used in the production of diagnostic antigen due to a major problem, i.e., false-positive reaction of e. coli host-derived proteins contaminating purified diagnostic antigen with human sera. The N (nucleocapsid) protein of Seoul virus causing haemorrhagic fever with renal syndrome (HFRS) was produced in E. coli BL21 (DE3), and used for the detection of N protein-specific antibodies in human sera. Using the N protein as a diagnostic antigen of HFRS, the false-positive reaction was cleared by merely mixing the test sera with the extract of E. coli host strain not harboring expression plasmid.

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Effect of Oxygen and Shear Stress on Molecular Weight of Hyaluronic Acid Produced by Streptococcus zooepidemicus

  • Duan, Xu-Jie;Yang, Li;Zhang, Xu;Tan, Wen-Song
    • Journal of Microbiology and Biotechnology
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    • 제18권4호
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    • pp.718-724
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    • 2008
  • Dissolved oxygen (DO) and shear stress have pronounced effects on hyaluronic acid (HA) production, yet various views persist about their effects on the molecular weight of HA. Accordingly, this study investigated the effects of DO and shear stress during HA fermentation. The results showed that both cell growth and HA synthesis were suppressed under anaerobic conditions, and the HA molecular mass was only $(1.22{\pm}0.02){\times}10^6 Da$. Under aerobic conditions, although the DO level produced no change in the biomass or HA yield, a high DO level favored the HA molecular mass, which reached a maximum value of $(2.19{\pm}0.05){\times}10^6 Da$ at 50% DO. Furthermore, a high shear stress delayed the rate of HA synthesis and decreased the HA molecular weight, yet had no clear effect on the HA yield. Therefore, a high DO concentration and mild shear environment would appear to be essential to enhance the HA molecular weight.

IEEE 802.1x 프레임워크 기반에서의 무선랜 보안 강화 방안에 관한 연구 (A Study on Intensified scheme to WLAN Secure based on IEEE 802.1x Framework)

  • 이준;홍성표;신명숙
    • 한국정보통신학회논문지
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    • 제10권1호
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    • pp.136-141
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    • 2006
  • IEEE 802.1x는 EAP(Extended Authentication Protocol)를 통해 해쉬 함수를 이용한 Challenge/Response, Keberos, 인증서를 기반으로 하는 TLS, One-Time Password 등 다양한 사용자인증 메커니즘들을 지원한다. 그러나 AP에 대한 인증 및 암호 메커니즘의 부재와 인증 프로토콜의 구조적 원인에 의해 스푸핑 및 DoS(Denial of Service) 공격 등에 취약하다. 본 논문에서는 IEEE 802.1x 프레임워크의 스푸핑 및 DoS 공격 취약성을 보완하여 안전한 사용자 인증 및 암호통신 서비스를 제공하는 무선랜 보안시스템을 제안하고자 한다. 제안 시스템은 공개키 암호기술을 이용하여 전송 메시지에 대한 무결성 서비스를 통해 안전한 암호통신을 제공하며, 인증초기단계를 통해 DoS 공격을 방지한다.

파랑 역추산 자료로부터 추정된 우리나라 남부해역의 파력 부존량 연구 (Analysis of Wave Power Resources in the Southern Sea of Korea estimated by Using Hindcasted Wave Data)

  • 김건우;정원무;박진순;이광수
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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    • pp.235.2-235.2
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    • 2010
  • In this study, the wave power resources at the southern sea of Korea were estimated by using the hindcasted wave data of previous researches. The used data were wave heights, periods and directions which were hindcasted around the Korea peninsular from 1979 to 2003. The spatial resolution of the hindcasted data is $1/6^{\circ}$(about 18 km). In winter, the northwest monsoon increase the wave power, while the wave power around Korea peninsular is very small in spring. The maximum value of the annual mean wave power is about 13 kW/m at Gageo-do, Heuksan-do and western region of Jeju-do, while those at the southern sea of Korea is only 4 kW/m, which is relatively small. The wave power at Korean east sea is lower than that of Korean southern sea. We obtained the wave resources information, in a fine grid, at Gageo-do, Heuksan-do, and western sea of Jeju-do, by solving SWAN model with the boundary conditions of hindcasted wave data.

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구성의 학습원리에 기반한 초등 로봇 교육 도구로서의 WeDo 2.0 활용가능성 탐색 (A Study on the Applicability of WeDo 2.0 in Elementary School as a Tool for Robot Education Based on Constructivist Learning)

  • 박혜란;이소율;이영준
    • 한국컴퓨터교육학회 학술대회
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    • 한국컴퓨터교육학회 2017년도 하계학술대회
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    • pp.179-182
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    • 2017
  • 로봇의 중요성이 강조됨에 따라 2019년부터 초등 실과 교과에 로봇 교육이 포함된다. 그러나 일부 초등학교에서 현행되고 있는 로봇 교육은 학습자가 완성된 형태의 로봇을 조작하는 데 그친다는 점에서 구성주의 학습원리에 어긋난다. 구성주의 학습원리에 따르면 학습자는 각자에게 의미 있는 독창적인 모델을 중심으로 자신만의 세계를 만들고 그 속에서 지식을 구성해 나가야만 진정한 학습이 일어난다고 할 수 있다. 본 연구에서는 구성주의 학습원리에 기반한 초등 로봇 교육의 도구로서 WeDo 2.0을 소개하고 로봇 교육 도구로서 WeDo 2.0이 갖는 활용가능성을 탐색하였다. WeDo 2.0은 학습자에게 첫째, 자발적 학습환경, 둘째, 창의적 학습환경, 셋째, 체계적 학습환경, 넷째, 통합적 학습환경, 다섯째, 구성주의 학습환경을 제공한다. 이에 따라 향후 초등 로봇 교육에서 WeDo 2.0을 활용한 구체적인 교육 프로그램의 개발 및 적용이 필요하다.

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Long-term Variations of Chemical Properties in Controlled Horticultural Soils of Gyeongnam Province

  • Lee, Young-Han;Lee, Seong-Tae;Hong, Kang-Pyo;Lee, Sang-Dae;Kim, Je-Hong;Ok, Yong-Sik;Kim, Min-Keun;Kim, HyeRan
    • 한국토양비료학회지
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    • 제46권5호
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    • pp.308-312
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    • 2013
  • The monitoring of chemical dynamic changes in controlled horticultural lands is very important for agricultural sustainability. Field monitoring was performed to evaluate the soil chemical properties of 200 controlled horticultural soil samples in Gyeongnam province every 4 years from 2000 to 2012. Soil chemical properties such as pH, amount of organic matter, available phosphate, nitrate nitrogen, and exchangeable potassium, calcium, magnesium, and sodium were analyzed. The amount of exchangeable calcium and soil pH were significantly higher in 2012 than in 2000. In 2012, the frequency distribution for values of pH, organic matter, available phosphate, and exchangeable potassium, calcium, and magnesium that were within the optimum range was 16.0%, 22.5%, 11.5%, 3.5%, 2.5%, and 5.0%, respectively. Especially, available phosphate and exchangeable calcium were excess level with portions of 76.0% and 96.5%, respectively. These results indicated that a balanced management of soil chemical properties can reduce the amount of fertilizer applied for sustainable agriculture in controlled horticultural lands.

Stem Rot of Strawberry Caused by Sclerotium rolfsii in Korea

  • Kwon, Jin-Hyeuk;Jeong, Sun-Ki;Son, Kyeng-Ae;Kim, Tae-Seung;Lee, Chun-Hee;Song, Geun-Woo;Park, Chang-Seuk
    • 한국식물병리학회:학술대회논문집
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    • 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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    • pp.129.1-129
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    • 2003
  • A destructive stem rot of strawberry (cv. Akihime) occurred sporadically in farmers' fields around Daegok-Myeon, Jinju City, Gyeongnam province in Korea. The infected plants showed stem and crown rot, sometimes whole plant blighted. White mycelia spread over stems of infected clones and sclerotia formed on the old lesions near to soil surface. The fungus formed white colony on PDA and showed maximum mycelial growth and scleotial formation around 30$^{\circ}C$. The fungus usually have many narrow mycelial strands in the aerial mycelium and the width were 4.0∼10.0$\mu\textrm{m}$. The typical clamp connections were formed on the mycelium. The shape of sclerotia was globoid and 1.0∼2.8 mm in size. The fungus was isolated repeatedly from the infected tissues and identified as Sclerotium rolfsii. The fungus was inoculated to strawberry and confirmed its pathogenecity This is the first report on the stem rot of strawberry caused by Scierotium rolfsii in Korea.

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하천그룹화 방법을 이용한 수질개선 하천유역의 우선순위 선정 (Selection Priority of Tributary Catchments for Improving Water Quality using Stream Grouping Method)

  • 조병욱;최정호;이상진;김영일
    • 한국물환경학회지
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    • 제28권1호
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    • pp.18-25
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    • 2012
  • For effective watershed management, it is very important to select the tributaries through selection and concentration of targeted tributary catchments for improving water quality within the limited financial conditions. This study introduced the selection and diagnosis procedure of tributary catchments for improving water quality at Chungcheongnam-do based on water quality and flowrate monitoring, stream grouping method. The tributaries with high value of water quality and flowrate were selected for improving water quality according to stream grouping method. The diagnosis of selected tributaries for improving water quality was performed with analysis of the pollution load (generated, discharged, delivered) and point source discharged pollution load density. The plans for improving water quality of tributaries were suggested thorough various diagnosis of tributary catchments. For improving water quality of tributaries in Chungcheongnam-do, the tributary catchments in the Dangjin, Asan, Yesan, Cheonan, Hongseong area should be preferentially considered. The water quality improving plans for those tributary catchments, in accordance with the reduction of sources of pollution by population and livestock, should be established.

염분스트레스에 의한 소나무잎 Peroxidase의 활성 및 Isozyme Pattern의 변화 (The Changes of Peroxidase Activity and Isoperoxidase Patterns from Pine Needles under the Salinary Stress)

  • 이미영
    • The Korean Journal of Ecology
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    • 제20권5호
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    • pp.315-321
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    • 1997
  • Peroxidase activities and isozyme patte군 of the pine needles (Pinus densiflora) were examined and compared in the coastal regions of Anmyum-Do(Choongnam, Taean-Gun) and inland regions of Shinchang-Myun(Choongnam, Asan-City). The pine needle peroxidase from Anmyum-Do showed approximately three times higher specfic activity than Shinchang pine needle peroxidase. The pine needle extracts of Anmyun-Do and Shinchang contained three anionic isoperoxidases, named A1, A2 and A3, when subjected to starch gel electrophoresis at pH 7.0. Cjationic isoperoxidases could not be found in both extracts., However, there existed unique isoperoxidase An only from the extracts of Anmyun-Do pine needles under the salinary environment. Moreover, the specific activities of catalase and glucose-6-phosphate dehydrogenase from Anmyun-Do, known for the inducible enzymes under the stress condition, were about 1.8 times higher than those of Shinchang pine needles. However, the specific activities of other enzymes did not show great differences between the two regions. Considering the above results of the higher specific activity of peroxidase and the unique expression of isoperoxidase An, pine needle peroxidase might involve in the defence mechanism against the salinary stress of Anmyun-Do.

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강원지역의 산사태 위험지 분포 현황에 관한 연구 (The Study on the Status of Landslide Risk Region in Kangwon-Do)

  • 이승호;이민규;장범수;심정훈
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2005년도 춘계 학술발표회 논문집
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    • pp.846-853
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    • 2005
  • The whole death by disaster is totalized to 1,515 person from 1993 to 2004 year in our country. In this section life damages by landslide is totalized 357 people(about 24% of whole life damage). About 36 people are died by landslide(such as cutting area failure every year). Kangwon-do need a lot of interests and prevention because dangerous area that landslide occurrence is more than other area at summer localized downpour or thawing season and there is landslide occurrence possibility area more than other area. Kangwon-do area is higher than other area in natural disaster incidence and damage scale because topography and a lot of rainfalls by summer localized in Kangwon-Do than other area. In this study, dangerous area of landslide occurrence possibility is analyzed and compared Kangwon-Do with other areas in our country. as a result, every year we have experienced landslide occurrence and natural disaster. accordingly, we urgently need to prevent landslide occurrence and natural disaster by analy-zed source about landslide occurrence and condition of disaster in Kangwon-Do and suitable engineering method and construction work.

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