• 제목/요약/키워드: Scavenger

검색결과 542건 처리시간 0.031초

논 서식 물땡땡이과의 분포 특성 (Distribution Characteristics of Water Scavenger Beetles (Hydrophilidae) in Korean Paddy Field)

  • 한민수;방혜선;김명현;강기경;정명표;이덕배
    • 한국환경농학회지
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    • 제29권4호
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    • pp.427-433
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    • 2010
  • 논을 포함한 주변의 일시적 또는 연속적인 정수지를 가지는 논생태계는 다양한 수서생물의 서식처를 제공함으로서 국가 생물다양성 확보를 위한 중요한 역할을 하고 있다. 하지만, 최근 수로정비, 경지정리 등에 의해서 서식환경에 변화가 일어나고 있으며, 앞으로도 계속적으로 일어날 것이다. 따라서, 본 연구에서는 논생태계 내에 출현하는 수서곤충 중에서 상위 포식자 역할을 하고 있는 물땡땡이류의 전국 분포 조사를 하였다. 그 결과 논 내에서 총 15종의 물땡땡이류가 확인되었다. 그중 전국적으로 애넓적물땡땡이(98.6%)와 점물땡땡이(87.7%)가 높은 출현빈도를 나타냈다. 대부분의 물땡땡이류는 경지정리가 이루어진 들에 위치한 논(33.7%)보다는 곡간에 위치한 논(5.0%)에서 출현빈도가 높았다. 한일넓적물땡땡이(1.4%), 등볼록물땡땡이(2.9%) 및 새가슴물땡땡이(4.3%) 3종은 곡간과 들 모든 지역에서 낮은 출현빈도를 보였다. 잔물땡땡이, 애물땡땡이, 알물땡땡이, Berosus elongatulus, 점박이물땡땡이, 뒷가시물땡땡이 및 북방물땡땡이 7종은 지역 특이적 분포 특성을 나타냈다. 이러한 종들은 향후 기후변화를 포함한 농업환경변화에 따른 논생태계 생물의 변화를 연구함에 있어서 좋은 지표로 활용될 수 있을 것으로 판단된다.

Soraphinol C, a New Free-Radical Scavenger from Sorangium cellulosum

  • Li, Xuemei;Yu, Tae-Kyung;Kwak, Jong-Hwan;Son, Byoung-Yil;Seo, Young-Wan;Zee, Ok-Pyo;Ahn, Jong-Woong
    • Journal of Microbiology and Biotechnology
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    • 제18권3호
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    • pp.520-522
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    • 2008
  • A new compound named soraphinol C (1) was isolated from myxobacteria Sorangium cellulosum KM1001 a soil isolate, together with a structurally related known compound, 4-hydroxysattabacin (2). These compounds were isolated by silica gel column chromatography and recycling preparative HPLC, consecutively. The structures of the compounds were determined on the basis of combined spectroscopic analyses. Compounds 1 and 2 exhibited antioxidant activity as a radical scavenger in the experiment using a hydrophilic free-radical initiator, 2,2'-azobis(2-amidinopropane)dihydrochloride with ORAC values of 0.956 and 0.617, respectively.

건조 대추의 변형기체포장 (Modified Atmosphere Packaging of Dry Jujube)

  • 하정욱;이동선
    • 한국식품저장유통학회지
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    • 제4권3호
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    • pp.265-270
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    • 1997
  • Effect of modified atmosphere packaging conditions on quality changes of dry jujube was investigated. Dry jujubes with moisture content of 26.7% were packaged in PET/Al/PE film pouches with modified atmospheres. The tested packages include those with normal air, vacuum, CO2 flushing, N2 flushing and O2 scavenger. Packages were stored at 25$^{\circ}C$ for 6 months, during which ascorbic acid concentration, browning level, titratable acidity and surface color were measured. Generally modified atmosphere packages could improve quality retention of dry jujubes except that vacuum package resulted in large surface color change. CO2-flushed package showed the best quality retention of high ascorbic acid content and low browning during 112 days, but caused high amounts of ascorbic acid destruction and browning in longer storage. In all the modified atmosphere packages titratable acidity reached a maximum followed by decline and subsequent rise, while it increased linearly with time in normal air package. Considering ascorbic acid retention browning level and surface color changes during 112 days, the packages of CO2 flushing and N2 flushing were better than others.

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Parameters affecting the recovery of silver (Ag) using photocatalytic ZnO nanopowder prepared by solution-combustion method.

  • B.B. Bhattarai;Lee, Ju-Hyeon;Park, Sung
    • 한국재료학회:학술대회논문집
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    • 한국재료학회 2003년도 춘계학술발표강연 및 논문개요집
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    • pp.49-49
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    • 2003
  • Nanometer sized zinc oxide (ZnO) powder was synthesized by a novel "solution-combustion method" and its photocatalytic activity was evaluated with the recovery of Ag from a used photofilm developing solution. Different parameters affecting the reaction rates like wavelength of the W light used, reaction temperature, mass of the used photocatalyst, and effect of scavenger were tested. The optimum parameters were found as follows. UV wavelength of less than 385nm, reaction temperature between 40- 60 $^{\circ}C$, photocatalyst concentration of 3-6 g/1, and scavenger concentration of 0.3-0.4 g/1.

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Current Scenario of Gas Scavenging Systems Used in Active Packaging - A Review

  • Gaikwad, Kirtiraj K.;Lee, Youn Suk
    • 한국포장학회지
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    • 제23권2호
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    • pp.109-117
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    • 2017
  • Due to the rise of customer's alertness about fresh foods to health, in the past few years, the consumption of fresh food has increased sturdily. The use of gas scavengers is the most appropriate packaging technologies for fresh, fresh-cut produces and in ready to eat products. The gas absorber/scavenger has ability to protect or stabilize the wanted properties and shelf life of food. The success of gas absorbers in food depends on many parameters such as types of foods, storage temperature, relative humidity, initial gas concentration, and the characteristics of package materials. In this review article, we focus on the most recent research trends in gas scavenging systems used in food packaging, future trends. Intense research from industry and engineers remains important to the development of gas scavenging package that fulfill consumer requirements, enhance product quality, and offer environmentally friendly design and cost-effective application.

내분비계장애물질 평가방법의 최적화 및 Apoptosis에 관한 연구 (Optimazation of the Assement and Apotosis of Endocrine-Bisphenol A Disruptors)

  • 안광현;이경아;김봉희
    • Environmental Analysis Health and Toxicology
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    • 제19권3호
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    • pp.251-259
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    • 2004
  • Xenoestrogens are chemicals with diverse structure that mimic estrogen. Bisphenol A, a monomer of polycarbonate and epoxy resins, has been detected in canned food and human saliva. Bisphenol A stimulate cell proliferation and induce expression of estrogen -response genes in vitro. The purpose of the this study was to evaluate cell proliferation of bisphenol A in the presence of a rat liver 59 mix contaning cytochrome P450 enzymes and Cu (II). The fragmentation of intact DNA, a parameter of apoptotic cell death, was evaluated quantitatively by diphenylamine reaction method. Bisphenol A induced apoptotic cell death in a dose-dependent manner The effect of radical scavenger on the apoptotic cell death induced bisphenol A was investigated. The DNA fragmentation induced by bisphenol A was significantly inhibited by addition of radical scavenger to the culture medium. This indicated that elevated oxidative stress caused by imbalance between the production and removal of free radicals occurred in cells. Taken together, these results suggest that free radical reacts with Cu (II) leading oxidative stress.

윤활시스템에서 마모메카니즘에 미치는 물리화학적 영향에 관한 연구(I) (A Study on the Effect of Physico- Chemical Factors in Wear Mechanism in a Lubricated Concentrated Contact (I))

  • 최웅수;권오관;문탁진;유영홍
    • Tribology and Lubricants
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    • 제4권1호
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    • pp.36-42
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    • 1988
  • 고온, 고속의 가혹한 조건하에서 윤활유의 열분해시 생성되는 수소의 발열반응에 의한 이차적인 열활성화 에너지에 기인되어 금속의 마멸현상을 가속화시키는 열활성화이론을 기본으로 하여 수소의 영향을 제거 혹은 감소시키기 위해 새로운 첨가제인 diethyl-3,5-di-t-butyl-4-hydroxy benzyl phosphonate(DEP)을 합성하였다. Termal degrading 실험과 열역학적 고찰을 통하여 합성첨가제인 DEP가 hydrogen scavenger로서의 작용 가능성을 확인하였다.

생약 추출물에 의한 superoxide와 hydroxyl 라디칼 소거능 검색 방법의 개선 (An Improved method in Screening of Superoxide and Hydroxyl Radical Scavenging Activities of Plant Medicinal Extracts)

  • 이호섭;강대길
    • 생약학회지
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    • 제32권3호통권126호
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    • pp.253-256
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    • 2001
  • The present study was designed for the improvement of routine measurement of superoxide and hydroxyl radical scavenging activities utilized by a microplate reader. Superoxide radical scavenging activity by the ascorbic acid, which is a well-known superoxide scavenger, was determined in a dose-dependent manner. Hydroxyl radical scavenging activity by the thiourea, which is a well-known hydroxyl radical scavenger, was also well detected in a dose-dependent manner. Our results suggest that the use of microplate reader to assay the superoxide and hydroxyl radical scavenging activities improves the accuracy of data and enables the use of much smaller amounts of samples and/or reagents, with much simpler experimental procedure. Therefore, These methods appear to be suitable for screening of superoxide and hydroxyl radical scavenging activities in both the plant medicinal extracts and the isolated compounds.

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芳香族할라이드의 Hot Atom Chemistry 스캐벤져, 溫度 및 酸素의 效果 (Hot Atom Chemistry of Aromatic Halides : Scavenger, Temperature and Oxygen Effect)

  • 최재호;박용찬;손미자
    • 대한화학회지
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    • 제9권2호
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    • pp.78-80
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    • 1965
  • The organic yields(i.e., fraction of nuclear events resulting in organic compound formation) of the radioactive neutron capture reactions of the halogens in purified aromatic halides have been determined in the liquid and solid state, in the presence of scavenger, elemental halogen for thermal atoms, and in the presence of oxygen. Among the important results are; (1) organic yields of the halides are due in part to hot processes and in part to thermal processes; (2) temperature (from liquid state to solid state); (3) the organic yield of chlorobenzene is the same in the solid phase as in the liquid phase whereas the yields of the bromo-and iodobenzene are higher in the solid.

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