• Korean Journal of Food Science and Technology
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• v.42 no.5
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• pp.521-526
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• 2010

A high-performance liquid chromatography (HPLC) method was established for the determination of fluoroquinolones in milk. Protein was removed by using trichloroacetic acid in order to increase a mean recovery of milk. The extracts were using $Strata^{TM}$-X solid-phase extraction cartridge. The analytes were detected by HPLC on a $C_{18}$ column. HPLC method with fluorescence detection system (Ex: 278 nm, Em: 456 nm) provided a high degree of sensitivity in detecting fluoroquinolones. The limits of quantitation (LOQ) and mean recoveries of fluoroquinolones were 40 ${\mu}g$/kg and 73.6-95.2% (ofloxacin), 10 ${\mu}g$/kg and 77.3-91.9% (norfloxacin), 20 ${\mu}g$/kg and 91.6-94.3% (ciprofloxacin), 10 ${\mu}g$/kg and 81.0-87.8% (enrofloxacin), 10 ${\mu}g$/kg and 71.3-81.0% (sarafloxacin), 10 ${\mu}g$/kg and 89.4-90.8% (orbifloxacin), 2 ${\mu}g$/kg and 69.4-85.5% (danofloxacin).

• Analytical Science and Technology
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• v.33 no.2
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• pp.59-67
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• 2020

Nadolol is a β-blocker drug, which effectively manages hypertension and angina pectoris. Its chemical structure allows the formation of four possible stereoisomers. A coupled column high-performance liquid chromatographic (HPLC) system with UV and fluorescence detection was investigated for simultaneously determining four nadolol enantiomers in human plasma. The plasma samples were prepared using a convenient liquid-liquid extraction process and passed through HPLC. Nadolol was initially separated from the endogenous compounds or other impurities in human plasma on a Phenomenex silica column, and its enantiomers were resolved and determined on a Chirapak AD-H column. The developed HPLC method achieved an effective chiral separation and significantly eliminated endogenous compound interference. This optimal HPLC method was validated following FDA guidelines. The results showed good selectivity, linearity, accuracy (90.50 % - 105.27 %), and precision (RSDs < 9.52 %) for each enantiomer. This method was also successfully applied to determine nadolol enantiomers in the plasma samples of a healthy male volunteer (after orally administering 80 mg racemic nadolol), proving its suitability for nadolol stereoselective pharmacokinetic studies.

• Korean Journal of Veterinary Service
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• v.35 no.3
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• pp.175-182
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• 2012

Rotaviruses have been known to be a major etiological agent of gastroenteritis in both infants and young animals. Subsequently new rotaviruses, which were morphologically indistinguishable but antigenically and electrophoretically distinct with each other, were reported from several animals throughout world including Korea. These new rotaviruses were named as non-group A or group B or group C rotaviruses and so on. It has been very difficult to isolate and grow the non-group A rotaviruses in vitro, and this has greatly limited the characterizations of non-group A rotaviruses and serological studies. In this study, monoclonal antibodies (MAbs) against porcine non-group A rotavirus were produced and characterized. The VP6 gene of porcine group C rotavirus Korean isolate(#06-52-1) was cloned and expressed. For expression of VP6 gene, baculovirus expression system was applied. The VP6 gene and expressed protein in the recombinant virus were confirmed by polymerase chain reaction (PCR), indirect fluorescence antibody (IFA) test and Western blot, respectively. The expressed VP6 was used for MAbs production. The MAbs produced in this study would be promising as diagnostic reagents for detection of group C rotavirus infection.

• Journal of Environmental Health Sciences
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• v.47 no.5
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• pp.496-503
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• 2021

Background: Considering the expenses of and difficulties in arsenic speciation by high performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS), alternative measurement methods should be useful, especially for large-scale research and projects. Objectives: A measurement method was developed for arsenic speciation using HPLC-atomic fluorescence spectrometry (HPLC-AFS) as an alternative to HPLC-ICP-MS. Methods: Total arsenic and toxic arsenic species in some seafoods were determined by atomic absorption spectrometry coupled with hydride vapor generation (AAS-HVG) and HPLC-AFS, respectively. Recovery rate of arsenic species in seafood was evaluated by ultra sonication, microwave and enzyme (pepsin) for the optimal extraction method. Results: Limits of detection of HPLC-AFS for As³⁺, dimethylarsinate (DMA), monomethylarsonate (MMA) and As⁵⁺ were 0.39, 0.53, 0.60 and 0.64 ㎍/L, respectively. The average accuracy ranged from 97.5 to 108.7%, and the coefficient of variation was in the range of 1.2~16.7%. As³⁺, DMA, MMA and As⁵⁺ were detected in kelp, the sum of toxic arsenic in kelp was 40.4 mg/kg. As³⁺, DMA, MMA and As⁵⁺ were not detected in shrimp and squid, but total arsenic (iAS and oAS) content in shrimp and squid analyzed by AAS-HVG were 18.1 and 24.7 mg/kg, respectively. Conclusions: HPLC-AFS was recommendable for the quantitative analysis method of arsenic species. As toxic arsenic species are detected in seaweeds, further researches are needed for the contribution degree of seafood in arsenic exposure.

• Journal of Radiation Protection and Research
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• v.25 no.4
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• pp.223-232
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• 2000

Comparative study was performed for the assessment of DNA damage and Chromosomal aberration in human lymphocyte exposed to low dose radiation using fluorescence in situ hybridization(FISH) and single cell gel electrophoresis(SCGE). Chromosomal aberrations in human lymphocytes exposed to radiation at doses of 5, 10, 30 and 50cGy were analysed with whole chromosome-specific probes by human chromosome 1, 2 and 4 according to PAINT system. FISH with chromosome-specific probe has been used to be a valid and rapid method fer detection of chromosome rearrangements induced by low dose radiation. The frequencies of stable translocation per cell equivalents were 0.0116, 0.0375, 0.040f, 0.0727 and 0.0814 for 0, 5, 10, 30 and 50cGy, respectively, and those of dicentric were 0.00, 0.0125, 0.174, 0.0291 and 0.0407 respectively. Radiation induced DNA damage in human lymphocyte in a dose-dependent manner at low doses from 5cGy to 50cGy, which were analysed by single tell gel electrophoresis(SCGE). From above results, FISH seemed to be useful for radiation biodosimetry by which the frequencies of stable aberrations in human lymphocyte can be observed more easily than by conventional method and SCGE also seemed to be sensitive method f9r detecting DNA damage by low dose radiation exposure, so that those methods will improve our technique to perform meaningful biodosimetry for radiation at low doses.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.640-647
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• 2016

By minimizing fluorescence interference phenomena, aequorin-based luminescence technology can provide a relatively sensitive detection platform with integration of $G{\alpha}16$ protein in order to track internal calcium mobilization by G protein-coupled receptors (GPCR). In this type of cell-based functional assay format, it is essential to optimize the transfection process of a receptor and $G{\alpha}16$ protein. For this study, corticotropin releasing factor receptor subtype 2(CRF2) was set as a model system to generate three stable cells with CRF2 and $G{\alpha}16$ in addition to transiently transfected cells under three different conditions. Agonist (sauvagine) and antagonist (K41498) responses in those cells were analyzed to develop the optimum transfection process. As a result, the effective signal ratio in the dose response experiments of sauvagine and K41498 were at least 10-fold higher (z'=0.77) in CRF2-$G{\alpha}16$ stable cells. For the transient transfection cells, stable expression of $G{\alpha}16$ prior to the CRF2 represented a two-fold higher signal (z'=0.84) than the other cases of transient transfection. In conclusion, for the utilization of transient transfection processes to develop a cell-based GPCR functional assay system, it is suggested to introduce various target receptors after stable expression of $G{\alpha}16$ protein.

• Korean Journal of Acupuncture
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• v.27 no.2
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• pp.95-105
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• 2010

Objectives : The purpose of this study is to investigate the effect of Bacillus-fermented Scutellariae Radix acupuncture solution (SB) on interleukin(IL) production in mouse macrophage stimulatedby lipopolysaccaride(LPS). Methods : Productions of interleukins were measured y High-throughput Multiplex Bead based Assay with Bio-plex Suspension Array System based on $xMAP^{(R)}$(multi-analyte profiling beads) technology. To begin with, cell culture supernatant was obtained after treatment with LPS(1 ${\mu}g/mL$) and SB for 24 hour. Then, it was incubated with the antibody-conj${\mu}g$ated beads for 30 minutes. And detection antibody was added and incubated for 30 minutes. After incubating for 30 minutes, Strepavidin-conjugated Phycoerythrin(SAPE) was then added. Incubating for another 30 minutes, the level of SAPE fluorescence was analyzed on Bio-plex Suspension Array System. Results : The results of the experiment are as follows. SB significantly inhibited the LPS-induced production of IL-3($9.15{\pm}0.35$ pg/mL) by $6.92{\pm}0.05,\;7.21{\pm}0.11,\;6.96{\pm}0.33,\;and\;7.45{\pm}0.74$ pg/mL at the concentration of 25, 50, 100, and 200 ${\mu}g/mL$ in mouse macrophage RAW 264.7 cells (p<0.05). SB significantly inhibited the LPS-induced production of IL-5($7.30{\pm}0.48$ pg/mL) by $6.50{\pm}0.29,\;6.30{\pm}0.25,\;6.30{\pm}0.25,\;and\;5.80{\pm}0.25$ pg/mL at the concentration of 25, 50 100, and 200 ${\mg}g/mL$ in RAW 264.7 cells (p<0.05). SB significantly inhibited the LPS-induced productiion of IL-9($17.26{\pm}0.19$ pg/mL) by $15.01{\pm}0.43$ pg/mL at the concentration of 25 ${\mu}g/mL$ in RAW 264.7 cells(p<0.05). SB significantly inhibited the LPS-induced productioh of IL-13($187.80{\pm}2.90$ pg/mL) by $152.80{\pm}4.25,\;172.80{\pm}3.97,\;162.10{\pm}6.67,\;and\;165.30{\pm}11.80$ pg/mL at the concentration fo 25, 50, 100, and 200 ${\mu}g/mL$ in RAW 264.7 cells(p<0.05). SB significantly inhibited the LPS-induced production of IL-17($18.30{\pm}0.95$ pg/mL) by $13.30{\pm}1.25,\;13.80{\pm}1.11,\;13.30{\pm}0.75,\;and\;14.00{\pm}1.08$ pg/mL at the concentration of 25, 50 100, and 200 ${\mu}g/mL$ in RAW 264.7 cells(p<0.05). SB significantly inhibited the LPS-induced production of IL-23($43.90{\pm}0.83$ pg/mL by $39.50{\pm}1.26,\;38.00{\pm}1.78,\;and\;39.60{\pm}2.49$ pg/mL at the concentration of 25, 100, and 200 ${\mu}g/mL$ in RAW 264.7 cells(p<0.05). Conclusions : These results suggest that SB has anti-inflammatory activity related with its inhibition of IL-3, IL-5, IL-13, IL-17, and IL-23 production in macrophages.

• Korean Journal of Ecology and Environment
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• v.56 no.4
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• pp.339-347
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• 2023

Dissolved organic matter (DOM) is a key component in the biogeochemical cycling in freshwater ecosystem. However, it has been rarely explored, particularly complex river watershed dominated by natural and anthropogenic sources, such as various effluent facility and livestock. The current research developed a new analytical method for TOC/TN (Total Organic Carbon/Total Nitrogen) stable isotope ratio, and distinguish DOM source using stable isotope value (δ¹³C-DOC) and spectroscopic indices (fluorescence index [FI] and biological index [BIX]). The TOC/TN-IR/MS analytical system was optimized and precision and accuracy were secured using two international standards (IAEA-600 Caffein, IAEA-CH-6 Sucrose). As a result of controlling the instrumental conditions to enable TOC stable isotope analysis even in low-concentration environmental samples (<1 mgC L^-1), the minimum detection limit was improved. The 12 potential DOM source were collected from watershed, which includes top-soils, groundwater, plant group (fallen leaves, riparian plants, suspended algae) and effluent group (pig and cow livestock, agricultural land, urban, industry facility, swine facility and wastewater treatment facilities). As a result of comparing characteristics between 12 sources using spectroscopic indices and δ¹³C-DOC values, it were divided into four groups according to their characteristics as a respective DOM sources. The current study established the TOC/TN stable isotope analyses system for the first time in Korea, and found that spectroscopic indices and δ¹³C-DOC are very useful tool to trace the origin of organic matter in the aquatic environments through library database.

• Journal of Sensor Science and Technology
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• v.6 no.1
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• pp.35-42
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• 1997

The optical biosensor using the electrically controlled release of reactive reagent is developed for the detection of peroxide. Rapid degradation of polymer complex of PEOx and PMAA occurs as the applied current increases and thus released amount of HPA increases. The degradation velocity of polymer and the amount of HPA released are linearly proportional to the applied current. Peroxide is reacted with the released reagent by peroxidase and then the product, a fluorescent dimer DBDA, is formed. The monochromic light from light source (150W Xe arc ramp) excites the DBDA and the excited light is transmitted through an optical fiber to be detected by a photodiode array. The change of fluorescence intensity is related to the change of peroxide concentration. The peroxidase is entrapped in Ca-alginate get on the inner surface. The biosensor has the linear signal range of 0.025mM-10.mM peroxide. By applying the step function of peroxide, reproducibility of biosensor has been investigated. The mathematical model is constructed by the combination of enzyme kinetics with reactor flow model. Good agreement is obtained between the experimental result and model prediction in the sensor signal.

• Horticultural Science & Technology
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• v.31 no.3
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• pp.344-351
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• 2013

Microsatellite is one of the most suitable marker for cultivar identification as it has great discrimination power for cultivars with narrow genetic variation. The polymorphism level between 358 microsatellite primer pairs and 11 commercial cucumber cultivars was investigated. Thirty-one primer pairs showed high polymorphism within cucumber cultivars with different fruit types. These markers were applied for the constructing DNA profile data base of 110 commercial cucumber cultivars through multiplex PCR and fluorescence based automatic detection system. A total of 139 polymorphic amplified fragments were obtained by using 31 microsatellite markers. The average of PIC value was 0.610 ranging from 0.253 to 0.873. One hundred and thirty nine microsatellite loci were used to calculate Jaccard's distance coefficients for UPGMA cluster analysis. A clustering group of varieties, based on the results of microsatellite analysis, were categorized into plant shape and fruit type. Almost the cultivars were discriminated by marker genotypes. This information may be useful to compare through genetic relationship analysis between existing variety and candidate varieties in distinctive tests and protection of plant breeders' intellectual property rights through variety identification.