• Journal of the Korean Chemical Society
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• v.13 no.4
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• pp.313-316
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• 1969

In this paper a simple and rapid method is described for the determination of lead in monazite. A monazite sample was dissolved with hot concentrated sulfuric acid and diluted to 200 ml with distilled water. Lead is quatitatively separated by coprecipitating with strontium. Lead-strontium sulfate is dissolved in 3N NaOH soluion. An excess Zn-EDTA is added. The remaining zinc ion is titrated with standard 0.01 M EDTA solution using xylenol orange as indicator at pH 5 in the presence of KCN and acetyl acetone as masking agents.

• Korean Journal of Microbiology
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• v.20 no.1
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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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.10
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• pp.1715-1719
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• 2004

In order to help the preservation of the unshiu orange and pear, antimicrobial paper incorporating grapefruit seed extract and zeolite was applied to pack fruits. Unshiu orange was packed in a box (24${\times}$24${\times}$22 cm) attached with antimicrobial paper and then stored respectively at l$0^{\circ}C$. Pears were wrapped individually before storage at l$0^{\circ}C$. During the storage, weight loss, pH, total acidity, soluble solid content, microbial load and decay were measured as quality indices. Steady pH increase in unshiu orange was observed to slightly decrease total acidity during the storage with little difference between the packaging treatments. The microbial loads of total aerobic bacteria, and yeast/mold counts were suppressed during storage by the antimicrobial paper packaging, which also contributed to reducing the decayed unshiu orange. Limited reduction of total aerobic bacteria and yeast/mold counts was observed only for initial storage period for the pears wrapped with 9 and 12% antimicrobial agent-added papers. Antimicrobial paper was useful for the reduction of microbial load in unshiu orange and pear without other quality deterioration.

• Journal of Environmental Health Sciences
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• v.39 no.4
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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.

• 대한예방의학회:학술대회논문집
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• 2001.10a
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• pp.418-419
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• 2001

• 대한예방의학회:학술대회논문집
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• 2001.10a
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• pp.416-417
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• 2001

• 대한예방의학회:학술대회논문집
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• 1999.10a
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• pp.144-145
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• 1999

• Development and Reproduction
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• v.18 no.4
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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.

• Journal of Life Science
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• v.12 no.2
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• pp.182-187
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• 2002

In this study we have investigated the effect of Caesalpina sappann L. extracts on the apoptosis in NIH3T3 cells exposed to methylmethan sulfonate (MMS), an alkylating agent. MTT assay study showed that Caesalpina sappan L. extracts potentiate the MMS-induced viability. Cell morphology studies, acridine orange (AO) staining, and DNA fragmentation analysis indicated that the postincubation of Caesalpina sappan L. extracts increase the nuclear condensation of MMS-induced apoptotosis. These results suggest that Caesalpina sampan L. extracts contain components potentiating MMS-induced apoptosis of NIH3T3 cells.

• Membrane and Water Treatment
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• v.10 no.5
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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.