• Analytical Science and Technology
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• v.5 no.3
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• pp.249-261
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• 1992

Electrochemical behavior of the heavy lanthanide complexes of alizarin red S(ARS) has been investigated by d. c. polarography, differential pulse polarography and cyclic voltammetry. The reduction mechanism at a mercury electrode of alizarin red S as a complexing ligand showed a one step of two-electron transfer and the electron process is found to be reversible. Alizarin red S forms a 3:1 adsorptive complexes with lanthanides and the complexes are reduced via one step of two-elctron. The reduction potential of complex wave($P_2$) shifted more negatively than the ligand wave($P_1$). The linear calibration curves of the decreacing $P_1$ and increasing $P_2$ is obtained when the lanthanide concentration varies from $2.0{\times}10^{-6}M$ to $6.4{\times}10^{-5}M$ under the condition of pH 9.5, 0.1M LiCl and $1{\times}10^{-3}M$ ARS.

• Journal of Veterinary Clinics
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• v.27 no.3
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• pp.209-215
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• 2010

Canine coronavirus (CCV) is a cause of sporadic outbreaks of enteritis in dogs. This study was performed to carry out epidemiological investigation on the recent outbreaks of CCV enteritis of dogs and determined the potential prognostic factors affecting the survival of dogs. The 131 (34.4%) out of 381 fecal samples collected from dogs with enteritis were positive for CCV by RT-PCR. The fecal samples contained genotype I (30.5%), genotype II (29.0%), and both genotypes (40.5%) of CCV. The majority of dogs with CCV infection ranged 6-18 weeks of age. Age over 18 weeks was significantly associated with higher survival rate (P < 0.05). Of the clinical signs examined, dogs without anorexia were significantly higher survival rate (P < 0.01). The 90.1% of dogs with CCV infection were co-infected by CCV and CPV-2. From the results of this study, it can be concluded that CCV infection is widespread in the Korean dog population and CCV may be attributed to be one of the important agents causing enteritis in pups.

• Journal of Veterinary Clinics
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• v.26 no.2
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• pp.130-133
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• 2009

The use of screening tests as part of a diagnostic work-up is common in domestic canine practice, but understanding of the diagnostic test characteristics and factors affecting diagnostic accuracy is not clear among clinicians. This article was aimed to provide clinicians with a better understanding on the selection of test kits and with a proper interpretation of test results using an example from heartworm(Dirofilaria immitis) studies. From the literatures, diagnostic accuracy varied depending on the kits: percent average sensitivity and specificity of ELISA antigen-detecting kits were DiroChek(Synbiotics, USA) 78.1 and 95.2, SNAP(IDEXX, USA) 66.3 and 98.1, and Solo Step(Heska, Switzerland) 69.5 and 97.5, respectively, while the values for three hematological methods(Modified Knott's, direct smear and capillary tube) ranged from 38.4 to 81.8% and from 96.9 to 100%, respectively. Furthermore, it was also reported that the prevalence of heartworm disease in domestic dog populations varied depending on the regions studied: 2.5-22.8% for microfilarial test and 2.2-66.3% by ELISA. The values of predictive values for positive(PPV) and negative(NPV) provide useful information to clinicians on the probability of heartworm infection, but the PPV and NPV are greatly dependent on the heartworm prevalence. This suggests that PPV or NPV values of a test should be interpreted carefully in different clinical settings. Practical methods on the interpretation taking into account heartworm prevalence were discussed.

• Plant Biotechnology Reports
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• v.4 no.4
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• pp.253-260
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• 2010

Plant secondary metabolites have always been a focus of study due to their important roles in human medicine and nutrition. We transferred the isoflavone synthase (IFS) gene into soybean [Glycine max (L.) Merr.] using the Agrobacterium-mediated transformation method in an attempt to produce transformed soybean plants which produced increased levels of the secondary metabolite, isoflavone. Although the trial to produce transgenic plant failed due to unestablished hygromycin selection, transformed callus cell lines were obtained. The induction rate and degree of callus were similar among the three cultivars tested, but light illumination positively influenced the frequency of callus formation, resulting in a callus induction rate of 74% for Kwangan, 67% for Sojin, and 73% for Duyou. Following seven to eight subcultures on selection media, the isoflavone content of the transformed callus lines were analyzed by high-performance liquid chromatography. The total amount of isoflavone in the transformed callus cell lines was three- to sixfold higher than that in control callus or seeds. Given the many positive effects of isoflavone on human health, it may be possible to adapt our transformed callus lines for industrialization through an alternative cell culture system to produce high concentrations of isoflavones.

• Korean Journal of Food Science and Technology
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• v.41 no.3
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• pp.339-344
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• 2009

Concentrations of polycyclic aromatic hydrocarbon (PAH) in processed chestnut products were determined by HPLC/FLD. The methodology involved procedures of sonication with water, extraction with hexane, and clean-up on a Sep-pak florisil cartridge. The PAH limits of detection (LOD) and limits of quantitation (LOQ) ranged from 0.012 to 0.382 ${mu}g/kg$ and from 0.042 to 1.273 ${mu}g/kg$, respectively. The coefficients of variation for intra- and inter-day assays were 0.02-4.48% and 0.37-9.83%, respectively, and the accuracies were 81.95-125.44% and 79.89-116.53%, respectively. The overall recoveries for eight PAHs spiked into the processed chestnut products ranged from 87.83 to 100.56%. As a result, PAH contents were not detected in the processed chestnut products.

• Food Science of Animal Resources
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• v.31 no.1
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• pp.47-53
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• 2011

Salmonella enterica serovar Typhimurium (ST) is one of the most common serovars isolated from humans and animals. It has been suggested that ST infections in Koreans are largely due to the consumption of contaminated pork and beef. To investigate the genotypes, phage types, and antimicrobial resistance patterns for ST isolates of different origins, a total of 70 ST strains, including 19 isolates from humans, 44 isolates from pigs, and 6 isolates from cattle, were analyzed using pulsedfield gel electrophoresis (PFGE), phage typing, and antimicrobial susceptibility tests. Forty-three distinct PFGE patterns were generated from 70 ST isolates, which were grouped into 14 PFGE groups (from A to N) at the level of 75% similarity. The most prevalent group was the A (A1-A17 subtypes) group, encompassing 54.5% (38/70) of ST isolates. ST isolates from pigs and cattle mostly belong to groups A and L, whereas ST isolates from humans mostly belong to groups F and C. Antimicrobial susceptibility tests using 11 antimicrobial agents showed that resistance to tetracycline (TE) (81.4%) was highly prevalent, followed by streptomycin (S) (64.3%) and nalidixic acid (NA) (31.4%) resistance. A total of seventeen antimicrobial resistance patterns were observed. Only 8.6% of isolates, including a reference strain, were susceptible to all antimicrobial agents tested. The most prevalent resistance pattern was TE-S (37.1%), which was seen in 66.6% of bovine, 40.8% of swine and 21.1% of human isolates. Three ST isolates from humans (15.9%) showed resistance to 7-8 antimicrobials. The most predominant phage type (PT) was U302 (64.3%), followed by DT170 (10.0%). PFGE types did not coincide with antimicrobial resistance patterns and phage types; therefore, the combination of those types allowed for further differentiation between tested ST isolates.

• Korean Journal of Plant Taxonomy
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• v.35 no.2
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• pp.129-142
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• 2005

Somatic chromosome numbers of 19 taxa of Korean Rubus was investigated. Subg. Anoplobatus (2 species), subg. Cylactis (1 species), subg. Idaeobatus (15 taxa) and subg. Malachobatus (1 species) are found in Korea. All taxa belonging to subg. Idaeobatus except for R. parvifolius which shows tetrapolid and hexaploid are diploid. The basic chromosome number of the genus was x=7. New chromosome numbers for 5 taxa were reported here: R. hongnoensis of Jeju-island endemic species, 2n=14; R. longisepalus, 2n=14; R. longisepalus var. tozawai, 2n=14; R. parvifolius, 2n=28; R. parvifolius var. taquetii, 2n=28. The rest 12 taxa except for R. coreanus Miq was well counted as 2n=14 and well consistent with previous reports from China and Japan. Our new chromosome level for R. parvifolius as 6x may indicate that speciation by polyploidization has occurred within Korean population. Unlikely to Japanese population (2n=42), Korean population of R. buergeri has same ploidy level with Taiwanese population as 2n=56.

• Analytical Science and Technology
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• v.25 no.5
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• pp.265-272
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• 2012

Okamoto cavity was modified to generate high power (2.45 GHz, 2 kW) He, N2 and Ar plasmas with WR-340 waveguide. Many factors which influence to the plasma generation were optimized and investigated for the spectroscopic properties of the He plasma generated. Some of the important factors are the diameter of the inner conductor, the distance between the inner and outer conductors and the distance between the tip of the inner conductor and the torch. After optimization for the He, two torches (a commercial mini torch for ICP and a tangential flow torch made locally) were compared and showed similar results for the helium plasma gas flow of 25 L/min~30 L/min. A tall torch (extended) was used to block the air in-flow and reduced the background intensity at 340 nm region (NH band). Emission intensity was measured for determination of halogen element in the aqueous solution with power and carrier gas flow rate. Electron number density and the excitation temperature were on the order of $3.67{\times}10^{11}/cm^3$ and 4,350 K, respectively. These values are similar or a bit smaller than other microwave plasmas. It has been possible to analyze aqueous samples. The detection limit for Cl (479.45 nm) was obtained to be 116 mg/L and needs analytical optimization for the better performance.

• Analytical Science and Technology
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• v.26 no.5
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• pp.307-314
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• 2013

Selenium exists in various forms of chemical species. The activity and bioavailability is strongly dependent on its chemical form and concentration. Consequently the information on each selenium species and its concentration must be exactly determined for the food we take in. In this study, selenium species in seafood were separated and quantified by RP (reversed phase) HPLC (high performance liquid chromatography) coupled with ICP-MS (inductively coupled plasma mass spectrometry) using post-column isotope dilution. $^{79}Br$, which interferes on $^{80}Se$, has mostly been removed by solid phase extraction and then mathematical correction has been applied for the more accurate correction. The experimental result for CRM (certified reference material) DOLT-4 agreed well with the certified value but each selenium species could not be compared. SeCys (selenocysteine) and SeMet (selenomethionine) were the major species detected in seafood such as belt fish, spanish mackerel, and squid that have been serving as Korean diet. The concentrations found in Korean sea food for SeCys and SeMet were in the range of 0-661.6 mg/kg and 137.3-462.7 mg/kg, respectively.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.77.2-77.2
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• 2011

We present our follow-up observation of the recently discovered supernova in M101. Being only 6.4 Mpc away from the Earth, the object is a Type-Ia supernova discovered this close in decades. We followed up this event with various observing facilities including on-campus telescopes at Seoul National University, the McDonald observatoy's 2.1m telescope, and UKIRT 4-m telescope. The light curves and the preliminary analysis of the multi-wavelength data will be presented, which cover the wavelengths from optical to NIR.