• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.6
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• pp.946-950
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• 2004

Young radishes which were grown in the soil containing sulfur increased quinine reductase (QR) activity in Hepa 1clc cells and isothiocyanate-like compound analyzed by HPLC. QR inducing activity was maximum in young radishes grown with 1,818 g/㎥ sulfur and was decreased when the soil was neutralized with lime mortar in order to improve a recovery. These results have suggested that consumption of young radishes, especially grown in the presence of sulfur, would prevent from cancer incidence through inducing detoxification enzymes and could have therapeutic effects for chemoprevention.

• Journal of Food Hygiene and Safety
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• v.17 no.1
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• pp.20-25
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• 2002

This study was aimed to determine the urinary metabolite of profenofos, one of the organophos-phorus pesticides, as the biomarkers of exposure. Urine samples were collected fort 24 hours in metabolic cages after oral administration and dermal application of profenofos to rats. Identification of the derivatized urinary metabolite was determined by GC/MS and excretion time courses of the urinary metabolite was analyzed by GC/MS. Urinary metabolite of profenofos, 4-bromo-2-chlorophenol, was detected in rats urine both after oral administration and dermal application of profenofos. Parent compound was not detected in the experiment. In GC/MS, the mass spectral confirmation for 4-bromo-2-chlorophenol ion was identified at m/z 208.4-bromo-2-chlorophenol was excreted within 48 hours and 72 hours after oral administration and dermal application of profenofos, respectively. In this study, the same urinary metabolite of profenofos was detected both in oral and dermal exposure. Generally, excretion of the urinary metabolite after oral administration was detected faster than after dermal application. It is suggested that urinary 4-bromo-2-chlorophenol could be used as the biomarkers of exposure to profenofos.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.1
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• pp.63-71
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• 2012

As nanotechnology is a key industry, there is growing concern relating to the potential risk of nanoparticles. They are known to be released into the environment via various exposure routes. When nanoparticles are present in water environments, they are supposed to be illuminated by ultraviolet light, and the ecotoxicity of photoactive nanoparticles may be changed. In this study, a review of the ecotoxicity of photoactive nanoparticles, including the mechanisms of phototoxicity, are presented. In order to address this issue, studies on the ecotoxicity to soil and water organisms exposed to photoactive nanoparticles were investigated. The photoactive nanoparticles chosen for this study were zinc oxide, titanium dioxide and fullerene. Microorganisms, nematode, earthworm, algae and fish, etc., were chosen to assess the toxicity of nanoparticles using diverse methods. However, studies on the phototoxicity potentially induced by nanoparticles on UV illumination have been reviewed in only 8 studies. From a few studies, photoactive nanoparticles have shown high dissolution rates under UV conditions, with the released ions observed to profoundly influence test organisms. In addition, NPs exposed to UV produced reactive oxygen species (ROS). These ROS can induce oxidative stress in exposed organisms. Evidence of phototoxicity by nanoparticles were found based on previous studies.

• Polymer(Korea)
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• v.29 no.6
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• pp.613-616
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• 2005

In this word as the first step to develop optical biosensors for a single cell level analysis, the preparation method of nano-scale polymer hydrogel spheres containing an enzyme was set up and the feasibility of the spheres as optical biosensors was investigated. The horseradish peroxidase (HRP) was encapsulated in the PEG hydrogel spheres by suspension photopolymerization, yielding spheres of the average size of 305 nm. After the polymerization, the incorporation and activity of HRP within the spheres were determined by the production of fluorescence resulted from the enzymatic reaction between HRP and $\H_{2}O_{2}$. The fluorescence emission response of the HRP-loaded PEG hydrogel spheres increased by nearly 300$\%$ as hydrogen peroxide concentration was changed from 0 to 11 nM in the presence of Amplex Red. The results suggest that the method to prepare the PEG hydrogel nanospheres containing an enzyme could be used for developing optical biosensors to measure various analytes in the very small samples like a single cell.

• Journal of Korean Society of Forest Science
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• v.87 no.1
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• pp.98-105
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• 1998

We measured seedling growth, foliar nutrient and extract concentrations of 3-year-old Ginkgo biloba seedlings growing in a nursery following a single fertilization with nitrogen (N), phosphorus (P) and nitrogen plus phosphorus (N+P) fertilizers. Fertilization did not change foliage, stem and root biomass of the seedlings except for the high N+P treatment, Foliar N and P concentrations following fertilization varied according to the amount of fertilizers. In general, foliar N and P concentrations increased with fertilization, but fertilization with 400kg N/ha and 100kg P/ha decreased foliar N and P concentrations, respectively. Seedling growth and foliar nutrient concentrations showed that N and P were the growth-limiting nutrients in our study site. It was found that fertilization reduced the concentrations of secondary metabolites (Ginkgo flavon glycosides and terpene lactones) in foliages. It seemed there was a relationship between foliage biomass production and secondary chemicals in G. biloba seedlings.

• Korean Journal of Microbiology
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• v.43 no.1
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• pp.1-6
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• 2007

We describe a multiplex PCR method that can detect and differentiate simultaneously four different kinds of DNA viruses, Epstein-Barr virus (EBV), cytomegalovirus (CMV), hepatitis B virus (HBV) and parvovirus B19 (B19). Primers for the multiplex PCR reaction were designed to amplify specific regions of the EBV (pol), CMV (pol), HBV (pol) and B19 (ns) viral genomes and used to simultaneously detect individual viruses. In order to achieve optimal sensitivity and specificity for multiplex PCR, the thermo-cycling parameters, primer sequences, and concentration of each reaction components were optimized systematically. The sensitivity of the detection method ranged between 5 and 10 copies of viral genome with a mixture of multiple primer pairs. Furthermore, this highly sensitive test showed no cross-reactivity among the four viruses. Thus, the results obtained in this study provide evidence that the assay system is a good tool for supporting the diagnosis of viral infection and contamination.

• Korean Journal of Environmental Agriculture
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• v.16 no.1
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• pp.67-71
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• 1997

This experiment was conducted to test the allelopatic activity on germination and early seedling growth of weed species by barley and sorghum plants residues. The fresh barley extraction inhibited the germination and early seedling growth of weeds, Echinochloa crus-galli, Sataria viridis, and P. oleracea. As the extract concentration increased, the germination and early seedling growth of weeds was significantly inhibited. The water extraction of dried barley and sorghum residues also ehibited the strong inhibition effect on germination and Barley seedling growth of weeds. Digitaria sanguinalis, Siegesbechia pubescens, Sectaria viridis, P. oleracea, E. crus-galli. In the dried barley and sorghum residues mixture into the vermiculite, as the dried residue concentration ncreased, emergence percentage, length of shoot and root of weeds, D. saguinalis, S. viridis, S. pubescens, Ammaranthus lividus, and Solanum nigrum, was significantly inhibited. More than 10% concentration of dired residue caused 80% emergence percentage and growth inhibition. From this study, we conclude that barley and sorghym weeds. These results suggest that barley and sorghum has some possibility to control some weed species like natural herbicide.

• Korean Journal of Environmental Biology
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• v.19 no.2
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• pp.93-99
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• 2001

There are several ways to remove and treat toxic heavy metals in the environment: chemical, physical and biological ways. The biological treatment utilizes the natural reactions of microorganisms living in the environments. These reactions include biosorption and bioaccumulation, oxidation and reduction, methylation and demethylation, metal - organic complexation and insoluble complex formation. The biological reactions provide a crucial key technology in the remediation of heavy metal-contaminated soils and waters. According to recent reports, various kinds of heavy metal species were removed by microorganisms and the new approaches and removal conditions to remediate the metals were also tried and reported elsewhere. This was mostly carried out by microorganisms such as fungi, bacteria and alga. In addition, a recent development of molecular biology shed light on the enhancing the microorganism's natural remediation capability as well as improving the current biological treatment.

• Journal of Adhesion and Interface
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• v.9 no.2
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• pp.8-15
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• 2008

Microcapsules have been widely used in cosmetics and pharmacology as controlled delivery devices of various active materials. Chitosan is the second most plentiful natural biopolymer with biocompatibility and nontoxicity. The chitosan microcapsules were prepared by the water-in-oil (W/O) emulsion method using glutaraldehyde as a crosslinking agent. Span80 was used as an emulsifier, and mineral oil was used as a medium material. Perfectly spherical microcapsules were obtained in the size range of $2{\sim}10{\mu}m$. The effects of emulsifier concentration and stirring speed on the average particle size and distribution were investigated. Encapsulation and release behavior of the microcapsules with different amount of the crosslinking agent (glutaraldehyde), different chitosan contents and different emulsifier concentration conditions were also investigated. The release rate of riboflavin was controlled by the crosslinking density of the chitosan and amount of emulsifier in the preparation of the microcapsule.

• Journal of the Korean Society of Tobacco Science
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• v.2 no.2
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• pp.8-13
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• 1980

The inhibition effect of flavone and butylatedhydroxyanisole (BHA) on the microsomal activation of Cigarette Smoke Condensate (CSC) or its Neutral Portion (NP) was investigated in Rat. The activities of Latic acid dehydrogenase (LDH) in serum was measured in the time intervals of 3, 6, 12, 18, 24 and 30 hr, respectively, after the injection (ip) of CSC (5mg/kg) or NP (10mg/kg) to Wistar male rat. Flavone (1mg/kg) and BHA (1mg/kg) were injected along with CSC or NP. The significant enhancement of the LDH activity in serum was observed in both cases of rats treated with CSC and NP. A drastic decrease of LDH activity from 1040 unit to 641 unit was observed after 12 hours of injection of CSC along with flavone. In contrast with the case of flavone, BHA reduced the enzyme activity from 825 unit to 652 unit at the same condition of flavone. Therefore, flavone can be considered to be a better inhibitor on action of CSC in vivo.