• Analytical Science and Technology
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• v.21 no.2
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• pp.84-92
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• 2008

A method for the determination of trace amount of caffeine in urine and various drink samples using hollow fiber-liquid phase microextraction (HF-LPME) and capillary gas chromatograph/nitrogen phosphorus detector (GC/NPD) has been established. HF-LPME method has been optimized with respect to several experimental parameters including the effects of the hollow fiber length, extraction solvent, stirring mode, pH and salt concentration for the determination of caffeine from aqueous samples. The correlation coefficient of calibration curve for caffeine was 0.9994. The average recovery was 102%(n=3). The established method is feasible for the determination of trace amounts of caffeine in several aqueous sample. The limit of detection (LOD) and the limit of quantitation (LOQ) have been found to be 2.5 and 10 ng/mL, respectively. The established HF-LPME method for the analysis of caffeine from aqueous sample can be used for the determination of biological, food and environmental samples.

• Journal of agriculture & life science
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• v.45 no.6
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• pp.151-162
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• 2011

Methanol and hexane extracts from 35 species in 27 families of herbal plants were evaluated for their acaricidal activities against two-spotted spider mite, Tetranychus urticae by leaf-dipping and spraying methods in laboratory, pot and field, respectively. Acaricidal activities were different depending on herbal plants. When T. urticae was released on leaves of Phaseolus vulgaris var. humilis that were dipped in the 1,000 ppm hexane extracts from fruits of Torreya nucifer and Daphan genkwa, seeds of Xanthium strumarium and Pharbitis nil at one minute they experienced 56.8, 47.8, 47.7, and 47.7% mortalities, respectively. Dipping time influenced acaricidal activity, that is, one minute dipping was more effective than 30 second dipping of Phaseolus vulgaris var. humilis leaves. However, extracts of X. strumarium and P. nil seeds had comparatively high activities. Concentration of hexane extract of X. strumarium and P. nil seeds revealing LC50 were 1,824 and 1,899 ppm, respectively. Extracts of both plants from hot and cold water were not effective representing <20% mortality at 1,000 ppm. However, hexane extracts of X. strumarium and P. nil seeds were effective against T. urticae on P. vulgaris var. humilis representing 76.3 and 71.3% mortalities in pot, respectively. Control effects of hexane extract of P. nil seed were 50.8 and 35.1% at 2,000 and 1,000 ppm against T. urticae on Chrysanthemum morifolium in greenhouse, respectively.

• Korean Journal of Environmental Biology
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• v.30 no.3
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• pp.231-237
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• 2012

Toxicity of $Ni^{2+}$ and Tebuconazole were investigated via FETAX (Frog Embryo Teratogenesis Assay-Xenopus) protocol using domestic frog embryos. Embryos of Black-spotted pond frog, Rana nigromaculata, were incubated and toxic effects of $Ni^{2+}$ and Tebuconazole were investigated by probit analysis. As a result, mortality and malformation rates were increased and larval body length was decreased in a dose dependant manner of $Ni^{2+}$ and Tebuconazole. The half maximal effective concentration ($EC_{50}$) of $Ni^{2+}$ and Tebuconazole were 0.07, $12.7mg\;L^{-1}$, respectively and the half maximal lethal concentration ($LC_{50}$) of $Ni^{2+}$ and Tebuconazole were 4.2, 39.1, respectively. The teratogenic index (TI) were 61.4 in $Ni^{2+}$ and 3.1 in Tebuconazole, respectively. These results reveals that $Ni^{2+}$ and Tebuconazole suppress the development of Black-spotted pond frog embryos at the low concentration as showing teratogenic effects in other assay system. Therefore, teratogen assay system using the Rana nigromaculata embryos could be useful as a tool to evaluate the toxicity of the pollutants in environment.

• Korean Journal of Biological Psychiatry
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• v.4 no.1
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• pp.102-107
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• 1997

Ginseng root, as a folk medicine, has been used in far eastern countries for thousands of years. Ginseng extract has been shown to have a variety of effects on the activity of the central nervous system, promoting stimulation as well as inhibition of the cortical activity. A survey of the relevant literatures has indicated that the putative anxiolytic activity of red ginseng has not been scientifically investigated. Therefore, the present study was designed to assess anxiolytic effect of gingseng total saponins(GTS). The putative anxiolytic effects of several fractions of GTS were investigated in mice using an elevated plus maze paradigm. Single dose administration of TS Fr.-I showed anxiolytic action in mice. Anxiolytic effect induced by TS Fr.-I was similar to that induced by diazepam. TS Fr.-II, TS Fr.-III and TS Fr.-IV did not show the anxiolytic action compared with that of TS Fr.-I. It was suggested that regulation of GABAergic neurotransmission may be important in the action of GTS. The Interaction of GTS fractions with benzodiazepine receptor was performed using rat cortical membranes. GTS inhibited the binding of [3H] Ro 15-1788 on the benzodiazepine receptor. Among from TS fractions, the binding activity of GTS in the TS Fr.-IV was highest, which did not show the anxiolytic activity. From these results, we conclude that GTS has anxiolytic action, and this is not related to benzodiazepine receptor binding activity.

• Journal of Applied Biological Chemistry
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• v.61 no.1
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• pp.47-50
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• 2018

Ricania shantungensis is a pest causiong problems in many crops. We tested the possibility of controling Ricania shantungensis using essential oil of Valeriana fauriei which were extracted by three different methods (steam distillation, solvent and supercritical extraction). Steam distillation were showed the most high mortality to adult ($1,040{\mu}L/mL$) and nymph ($2,370{\mu}L/mL$) of R. shantungensis. The yield of steam distillation extraction was 0.67%, which was lower than other methods. However, it is determined that steam extraction was showed higher efficiency by considering time and cost. The result of this study showed the possibility of control R. shantungensis by essential oil of V. fauriei.

• Korean Journal of Weed Science
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• v.10 no.3
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• pp.214-220
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• 1990

To establish a greening assay for screening, and physiological and biochemical studies of the compounds affecting biosynthesis of plant pigments, were conducted on environmental factors, and on ways of incubation and illumination which affect plant greening. Greening was good when both cucumber and barley were grown for 5 to 6 days at $25^{\circ}C$ in darkness, when adaxial sides of cucumber cotyledons were contacted with the solution, and when barley leaf fragments were taken 0.5 to 2.0cm from the leaf tip. Potassium phosphate buffer(pH 6.0) at 10mM was most desirable for plant greening. The speed of greening during illumination was increased as the temperature increased from $15^{\circ}C$ to $35^{\circ}C$. The responses were sensitive more in cucumber than in barley, and in chlorophyll biosynthesis than in carotenoid biosythesis. The content of chlorophyll was greatest at the light intensity of 5000 and 1000 lux for cucumber and barley, respectively, but the biosynthesis of carotenoids were greatest at the light intensity higher than for chlorophyll. In use of solvents for dissolving chemicals, acetone, ethyl alcohol and DMSO at 10, 0.1 and 2.5% or less, respectively, did not affect the biosynthesis of plant pigments. $pI_{50}$ values were calculated for chemicals affecting pigment biosynthesis.

• Analytical Science and Technology
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• v.14 no.3
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• pp.221-229
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• 2001

The bioequivalence study of two tiropramide products was evaluated in 16 health male volunteers following intra-muscular injection. Test product was Tiram$^{(R)}$ injection (S Pharm. Co, Ltd.) and reference product was Tiropa$^{(R)}$ injection(D Pharm. Co., Ltd.). The drug concentration in plasma was determined by GC/MS for over a period of 8 hours after injection. Analysis of variance reveal that there are no differences in AUC (area under the plasma concentration-time curve from time zero to infinity), Cmax (maximum plasma concentration) and Tmax (time to reach Cmax). The differences of mean AUC, Cmax and Tmax between two products were 0.73, -1.385 and -12.994%, respectively. Minimum detectable differences (%) at ${\alpha}=0.05$ were all less than 20% given as a guideline (10.05, 17.90 and 19.01% for AUC, Cmax and Tmax, respectively). From these results, the two formulations of tiropramide are bioequivalent and thus, may be prescribed interchangeably.

• Journal of Bio-Environment Control
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• v.11 no.4
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• pp.168-174
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• 2002

A new circulating hydroponic system was invented for oriental melons grown in the greenhouse. For developing nutrient solution management techniques, we examined the changes of nutrient contents of circulating solution in three different types of new hydroponic systems. The yield and fruit quality of oriental melons in Hydroponics were better than those in soil culture. The substrate culture was appropriate fer hydroponics of oriental melons, and NFT was turned to be the opposite due to the physiological disorder during hot seasons. Yamazaki's melon solution with EC 2.0dS.m$^{[-10]}$ was the most appropriate for oriental melons. The new circulating hydroponic system seemed to be appropriate for oriental melons because of the stable EC, pH and the macro- and micro-element contents. NO$_3$-N, Ca and Mg contents in the circulating solution kept a good balance in all types of hydroponics. However, p content, compared to other types, decreased by the degree of 1 me.L$^{[-10]}$ in perlite medium. K content showed irregular status in perlite but showed the stable status in cocopeat. Generally, microelements, except Mo, showed stable absorption in the substrate culture. However, in NET, most of the elements showed irregular absorption except B and Mn. Microelement absorption, especially Cu, Zn and Mo, decreased during hot seasons.

• The Korean Journal of Mycology
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• v.42 no.3
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• pp.219-224
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• 2014

A gram-negative bacterium was isolated from spent substrate of Agaricus bisporus and showed marked antagonistic activity against Pseudomonas tolaasii. The bacterium was identified as Pseudomonas azotoformans by based on the cultural, biochemical and physiological characteristics, and 16S rRNA gene sequence. The isolated bacterium was saprophytic but not parasitic nor pathogenic to cultivation mushroom. The isolated bacterium for P. tolaasii cell was not sufficient for inhibition in vitro. Control efficacy of Pseudomonas azotoformans HC5 to brown blotch of P. tolaasii was 73, 78, and 71% on A. bisporus, Flammulina velutipes, and Pleurotus ostreatus, respectively. In the future, the suppressive bacterium may be useful for development of a biocontrol system.

• Korean Journal of Environmental Biology
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• v.35 no.4
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• pp.427-436
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• 2017

A fixed-precision-level sampling plan was developed to establish control of the two-spotted spider mite, Tetranychus urticae, in two strawberry greenhouses (conventional plot, natural enemy plot). T. urticae was sampled by taking a three-leaflet leaf (1 stalk) from each plant (3 three-leaflet leaves) from each sampling position. Each leaflet was divided into three different units (1-leaflet, 2-leaflet, and 3-leaflet units) to compare relative net precision (RNP) values for selection of the appropriate sampling unit. The relative net precision values indicated that a 1-leaflet unit was more precise and cost-efficient than other units. The spatial distribution analysis was performed using Taylor's power law (TPL). Homogeneity of the TPL parameters in each greenhouse was evaluated by using the analysis of covariance (ANCOVA). A fixed-precision-level sequential sampling plan was developed using the parameters of TPL generated from the combined data of the conventional plot and natural enemy plot in a 1-leaflet sampling unit. Sequential classification sampling plans were also developed using the action threshold of 3 and 10 mites for pooled data. Using the results obtained in the independent data, simulated validation of the developed sampling plan by Resampling validation for sampling plan (RVSP) indicated a reasonable level of precision.