• 제목/요약/키워드: Agent Orange

검색결과 77건 처리시간 0.025초

모나자이트 중의 납 정량을 위한 신속한 EDTA 적정법 (A Simple EDTA Titration Method for the Determination of Lead in Monazite)

  • 이철;조원지
    • 대한화학회지
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    • 제13권4호
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    • pp.313-316
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    • 1969
  • 모나자이트 중의 납함량을 신속하고 간편하게 결정하는 방법을 기술하였다. 즉 모나자이트 시료를 황산에 녹여 200ml가 되겠끔 희석하였다. 스트론튬으로 납을 정량적으로 분리한 후 3N 수산화나트륨에 녹였다. 여분의 Zn-EDTA를 가한 다음 남은 아연 이온을 0.01M EDTA표준용액으로 적정하였으며 이때 가리움제 (masking agent)러서 시안화칼륨 및 아세틸 아세톤을 가하였고 pH 5에서 자이렌을 오렌지(Xylenol orange)를 지시약으로 사용하였다.

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Plasmid pSL100의 curing, segregation 및 segregants 들의 재조합에 관한 연구 (Curing and segregation of pSL100 and recombination of its segregants)

  • 백형석;김국찬;이세영
    • 미생물학회지
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    • 제20권1호
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    • pp.11-20
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    • 1982
  • A study was undertaken to examine the effect of curing agents on the stability, curing and segregation of R plasmid pSL100. And also the stability, transfer frequency, and recombination of its segregants obtained from curing agent treatment were studied. Ethidium bromide, acridine orange, and mitomycin-C were used as curing agent. The results obtained were as follows ; 1. The curing agent ethidium bromide, acridine orange, and mitomycin-C were not effective for curing the multiple antibiotic resistant determinant of pSL100 in Salmonella typhimurium and Escherichia coli. However, they induced plasmid segregation with high frequency in S.typhimuruim LT-2strains. TcApSmCm, TcSmCmKm, TcApCm, TcAp, TcKm, Tc segregants were obtained. 2. The resistant markers of the segregents were transferred to S.typhimurium LT-2 strains with high frequencies whereas they were transferred to E.coli K-12 only with low frequencies. 3. The transconjugants obtained from conjugation between two different S.typhimurium segregants were similar to the phenotype of the original R factor pSL100 and the resistant markers were transferred to the S.typhimurium LT-2 or E.coli strain with equal frequencies, indicating that they are recombinants. 4. The transconjugants obtained from conjugation between pSL100 segrgants and pKM101, or pBR322 possessed the resistant markers of the two parental plasmids and they were transferred to both S.typhimurium and E.coli K-12 strains with the same frequencies and maintained stably, suggesting that they are also recombinants. 5. The recombinant pSL100 could be also obtained in rec A-strains of E.coli, suggesting that the gene function of rec A is required for the recombination of pSL100 segregants in E.coli.

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항균소재를 함유한 포장재로 포장한 밀감과 배의 저장중 품질 특성 변화 (Quality Characteristics of Unshiu Orange and Pear Packaged with Paper Incorporated with Antimicrobial Agents)

  • 박우포;정준호;조성환;김철환
    • 한국식품영양과학회지
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    • 제33권10호
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    • pp.1715-1719
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    • 2004
  • 항균성이 있는 것으로 알려진 자몽종자추출물에 젖산과 구연산을 각각 5%씩 첨가한 식물성 천연항균제 제재와 제올라이트를 첨가하여 항균포장지를 만든 다음 감귤과 배의 저장을 위한 포장재로로 사용하였다. 저장 기간중 품질 변화의 지표로 중량감소율, pH 산도, 가용성고형 물, 총균수, 효모 및 곰팡이수 등을 측정하였다. 감귤은 저장 2주가지 대조구와 항균제 6% 첨가 포장지 시험구의 중량 감소가 대체적으로 큰 것으로 나타났으나 그 이후에는 항균제 9$^{\circ}C$ 첨가 포장지 시험구의 중량 감소가 큰 것으로 나타났다. 포장직후 감귤의 pH는 3.77이 었으며, 저장 기간이 경과함에 따라 대체적으로 증가하였으며, 총산은 pH의 증가와는 반대로 대체적으로 감소하였다. 감귤의 저장전 총균수는 1.07 H $10^{5}$ CFW/g이었으며, 효모 및 곰팡이 는 4.9 H $10^4$ CFU/g이었다. 즉 감귤의 표피에 있는 미생물의 대부분은 효모와 곰팡이였으며, 저장 2주까지는 항균제 5% 첨가 포장지에서는 대조구와 비슷하거나 다소 높은 미생물수를 나타내었으나 다른 처리구는 대조구보다 낮아서 항균 효과가 있는 것으로 나타났다. 포장지에 항균제의 첨가 비율이 높을수록 감귤의 부패율은 낮았으며, 저장 4주에 항균제 12% 첨가 포장지로 포장한 시험구는 18.0%인데 비하여, 대조구는 34.7%로 나타났다. 배는 항균제 9% 및 12% 첨가 포장지로 포장한 시험구의 총균수, 효모 및 곰팡이수가 저장 2주까지는 다른 시험구보다 낮았으며, 12% 첨가 포장지의 효과가 더 큰 것으로 나타났다. 저장 2주 이후에는 항균제 9%, 12% 첨가 포장지 모두 미생물수가 급격하게 증가한 것은 항균포장지에 의한 배의 미생물 생육 억제 효과가 제한적일 수 있음을 나타내는 것이라고 판단된다. 따라서 다른 품질특성과 미생물수의 변화를 동시에 고찰하면 항균포장지에 의한 배의 저장은 2∼3주 이내로 제한적일 수 있을 것으로 보인다.다.

설문조사에 근거한 캠프 캐럴 인근 주민의 건강수준 (Health Status Based on Questionnaire Survey Among Residents Around Camp Carroll, Gyeongsangbuk-do, Korea)

  • 민영선;임현술;이관;박선애;이덕희;주영수;양원호;김근배;유승도
    • 한국환경보건학회지
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    • 제39권4호
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    • pp.312-321
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    • 2013
  • Objective: In May 2011, an interview with three United States Forces Korea veterans revealed that chemicals believed to be 'Agent Orange' were buried at Camp Carroll (situated in Waegwan, Chilgok-gun, Gyeongsangbuk-do, Korea) in 1978. Many hazardous chemicals, such as perchloroethylene (PCE), trichloroethylene (TCE), and organochlorines were subsequently found in a joint US-ROK environmental investigation, although dioxins or burial evidence related to 'Agent Orange' have been not uncovered. This study was carried out to investigate the relevance of hazardous chemical exposure and health effects of the residents around Camp Carroll. Methods: The authors conducted a health questionnaire survey among residents around Camp Carroll regarding Waegwan groundwater ingestion, length of residence in Waegwan, and physician-diagnosed disease history (such as cancer, hypertension, diabetes and etc.). Logistic regression was performed to identify the associations between hazardous chemical exposure and physician-diagnosed diseases. Results: Among the 5,320 residents, excluding those living outside the Waegwan area, 3,430 subjects age 30 and over were analyzed. Among females, upon correction of age, smoking history and Camp Carroll working history, a higher distribution in the Waegwan groundwater ingestion group was demonstrated for patients with physician-diagnosed cancer and hypertension. The odds ratios have a tendency to increase with increased length of Waegwan groundwater ingestion. Conclusions: This study may be limited by not adopting a cohort study for the evaluation of factors that may confound environmental exposure. Yet it is meaningful that the correlation between Waegwan groundwater ingestion and chronic diseases were found through regression analysis in female; and further, this outcome may be used as a sampling basis for a secondary epidemiologic study.

Biphasic Activity of Chloroquine in Human Colorectal Cancer Cells

  • Park, Deokbae;Lee, Youngki
    • 한국발생생물학회지:발생과생식
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    • 제18권4호
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    • pp.225-231
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    • 2014
  • Autophagy is a homeostatic degradation process that is involved in tumor development and normal development. Autophagy is induced in cancer cells in response to chemotherapeutic agents, and inhibition of autophagy results in enhanced cancer cell death or survival. Chloroquine (CQ), an anti-malarial drug, is a lysosomotropic agent and is currently used as a potential anticancer agent as well as an autophagy inhibitor. Here, we evaluate the characteristics of these dual activities of CQ using human colorectal cancer cell line HCT15. The results show that CQ inhibited cell viability in dose- and time-dependent manner in the range between 20 to 80 uM, while CQ did not show any antiproliferative activity at 5 and 10 uM. Cotreatment of CQ with antitumor agent NVP-BEZ235, a dual inhibitor of PI3K/mTOR, rescued the cell viability at low concentrations meaning that CQ acted as an autophagy inhibitor, but CQ induced the lethal effect at high concentrations. Acridine orange staining revealed that CQ at high doses induced lysosomal membrane permeabilization (LMP). High doses of CQ produced cellular reactive oxygen species (ROS) and cotreatment of antioxidants, such as NAC and trolox, with high doses of CQ rescued the cell viability. These results suggest that CQ may exert its dual activities, as autophagy inhibitor or LMP inducer, in concentration-dependent manner.

알킬화제인 MMS를 선처리한 NIH3T3 세포에서 소목 추출물 의한 세포고사의 촉진 (Extracts of Caesalpina sappan L. Potentiate the Apoptosis of NIH3T3 Cells Exposed to Methymethane Sulfonate)

  • 박종군;황성진;이정섭;전병훈;김원신
    • 생명과학회지
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    • 제12권2호
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    • pp.182-187
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    • 2002
  • 본 연구에서는 알킬화제인 methylmethane sulfonate (MMS)를 선처리한 NIH3T3세포에서 소목추출물의 효과를 분석하였다. MTT 분석결과 MMS에 의해서 유도된 세포생존률이 소목추출물에 의해서 감소되었다. 세포형태분석, acridine orange 염색법, 그리고 DNA fragmentation 분석에서 MMS에 의해서 유도된 세포고사의 특징인 핵 응축 및 DNA laddering이 소목추출물에 의해서 증가됨이 관찰되었다. 이러한 결과들로 소목추출물은 NIB73T3 세포에서 MMS에 의해서 유도된 세포고사를 촉진시킴을 보여준다.

Dye removal from water using emulsion liquid membrane: Effect of alkane solvents on efficiency

  • Ghaemi, Negin;Darabi, Farzaneh;Falsafi, Monireh
    • Membrane and Water Treatment
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    • 제10권5호
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    • pp.361-372
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    • 2019
  • Effect of different alkane based solvents on the stability of emulsion liquid membrane was investigated using normal alkanes (n-hexane, n-heptane, n-octane and n-decane) under various operating parameters of surfactant concentration, emulsification time, internal phase concentration, volume ratio of internal phase to organic phase, volume ratio of emulsion phase to external phase and stirring speed. Results of stability revealed that emulsion liquid membrane containing n-octane as solvent and span-80 (5 % (w/w)) as emulsifying agent presented the highest amount of emulsion stability (the lowest breakage) compared with other solvents; however, operating parameters (surfactant concentration (5% (w/w)), emulsification time (6 min), internal phase concentration (0.05 M), volume ratio of internal phase to organic phase (1/1), volume ratio of emulsion phase to external phase (1/5) and stirring speed (300 rpm)) were also influential on improving the stability (about 0.2% breakage) and on achieving the most stable emulsion. The membrane with the highest stability was employed to extract acridine orange with various concentrations (10, 20 and 40 ppm) from water. The emulsion liquid membrane prepared with n-octane as the best solvent almost removed 99.5% of acridine orange from water. Also, the prepared liquid membrane eliminated completely (100%) other cationic dyes (methylene blue, methyl violet and crystal violet) from water demonstrating the efficacy of prepared emulsion liquid membrane in treatment of dye polluted waters.