• Journal of the Korean Chemical Society
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• v.33 no.1
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• pp.97-105
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• 1989

This study deals with micellar effects on hydrolyses of p-nitrophenyl carboxylic esters(p-NPCE) mediated by 2-alkylbenzimidazole(R-BI) and sodium 2-alkylbenzimidazole-5-sulfonate(R-BISO$_3$Na) in aqueous and CTABr solutions. The reactions mediated by R-BI and R-BISO$_3$Na in micellar solutions are obviously slower than those by benzimidazole(BI) and sodium benzimidazole-5-sulfonate(BISO$_3$Na) respectively, and the reaction rates were decreased with increase of lengths of alkyl groups. This prestents a striking contrast to the reactions in aqueous solutions without added CTABr, of which the reaction rates are on approximately same levels. It seems due to steric effect of alkyl groups for R-BI and R-BISO$_3$Na in the Stern layer of micelle, and it is supported by measured activation parameters(${\Delta}H^{\neq},\;{\Delta}G^{\neq}\;and\;{\Delta}S^{\neq}$) of the reactions in aqueous and micellar solutions. In addition to nucleophilic ability of benzimidazole(BI) moiety of R-BISO$_3$Na on the reactions, these compounds with long alkyl groups(nonyl to pentadecyl) which form a micelle of themselves increase the reaction rates due to their micellar catalyses in aqueous solutions, not including CTABr. We measured the isotope effects to elucidate the mechanism of hydrolyses of p-nitrophenyl carboxylic esters, and the relative first order rate constant($k'_{H_2O}/k'_{D_2O}$) are on range of 2.5∼3.2. This range is too high to conclude that the hydrolyses of p-NPA mediated by various R-BISO$_3$Na proceed by nucleophilic mechanism. In other words, the reactions are assumed to proceed in part by general basic one, as compared with the reaction catalyzed by imidazole(IM) in aqueous solution.

• The Journal of the Petrological Society of Korea
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• v.7 no.1
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• pp.15-26
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• 1998

The Dabie-Sulu ultra-high pressure metamorphic (UHPM) zone is commonly suggested to be a collisional belt between the Sino-Korea craton (North China craton) and Yangtze craton (Zhai and Cong, 1996). Two important questions in formulating the tectonic evolution of the northeast Asia are : (1) the boundary between the UHPM zone and the Sino-Korea craton in the Shandong peninsula and (2) the extension of this Chinese UHPM zone into the Korean peninsula. There have been different opinions on the boundary between UHPM zone and the Sino-Korea craton in the Shandong peninsula. For example, the boundary has been suggested to be the Tan-Lu fault (Bai et al., 1993; Wang and Cong, 1996), or Wulian-Rongcheng fault (Cao et al., 1990). Our recent study finds out new evidences, indicating that the possible boundary is the Kunyushan granitoid complex zone, which occurs along the Wulian-Muping fault. Our new evidences are : (1) the basic rocks west to the Kunyushan granitoid zone are high-pressure granulites rather than eclogites (Zhai, 1996) with their Sm-Nd isotopic ages of 1750 Ma and 2788 Ma, representing their retrograde metamorphic and petrogenetic ages, respectively (Li et al., 1997b); (2) the orthogneisses west to the Kunyushan granitoid zone yield 2600-2900 Ma zircon ages and 1600-2020 Ma Rb-Sr and chemical U-Th-total Pb ages, with no younger data (Enami et al., 1993; Ishizaka et al., 1994), having a typical characteristic for the early Precambrian rocks in the Sino-Korea craton; (3) the orthogneisses east to the Kunyushan granitoid zone have 110-320 Ma isotopic ages with a peak value of 180-230 Ma, showing a typical characteristic of metamorphic rocks in the UHPM zone; (4) the Kunyushan granitoid zone consists of numerous granitic bodies, stocks and veins, which have 1900-2000 Ma, 610-710 Ma and 124-180 Ma istotopic ages indicating a long and complicated evolution history of this granitoid zone. There are many lenses and enclosures of metamorphic rocks from the Sino-Korea craton and Sulu UHPM belt in the Kunyushan granitoid zone. Zhai et al. (1998) have defined the Kunyushan granitoid zone as the Jiaodong Boundary complex zone. Some geologists suggested that the UHPM zone extend eastward to the Korea peninsula (Yin and Nie, 1993; Wang and Cong, 1996) and possibly to the Imjingang belt (Chang, 1994; Ree et al., 1996). Unfortunately, there has not been a conclusive evidence indicating that UHPM rocks occur in the Korea peninsula. In this regard, it becomes more important to compare metamorphic rocks in the Shandong peninsula with those in northern and southern Korea peninsula.

• The Journal of the Petrological Society of Korea
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• v.22 no.2
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• pp.153-177
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• 2013

To get the various data on geological information, distributional ratios and characteristics of constituent rocks with geologic ages and rock types were obtained by ArcGIS 10.1 program, digital geologic and geomorphic maps of 1:250,000 scale in Jeonnam and Gwangju areas. In the Jeonnam area, geologic ages can be largely divided into 7, in which their distribution ratios show decreasing trends in the order of Cretaceous, Precambrian, Jurassic, Quaternary, Age-unknown, Carbonifeorus-Triassic and Triassic, and the former fours make the most prevailing ratios of 94.80%. Rock types in the area can be assorted into 57 ones, in which major 7 ones occupy the dominant ratio of 71.68%. Among them, Kav (acidic volcanics+rhyolite and rhyolitic tuff) show much more distribution ratios than the others. It shows more aspects distributed in north, west, middle, east and south parts, especially in Sinan-Mogpo-Yeongam of west and Haenam of south parts in the area, respectively. On the other hand, geological ages in Gwangju area can be largely divided into 5, in which their distribution ratios show decreasing trends in the order of Jurassic, Quaternary, Cretaceous, Precambrian and Age-unknown, and the former fours occupy almost the whole ratio of 98.95%. Rock types in the area are 12 ones, in which major four ones make up the dominant value of 91.30%. Among them, Jurassic granites of the most dominant value are mostly occupied in the southwest-northeast part of the area. Next dominative Quaternary alluvium is mostly developed along the Yeongsan river, the Hwangryong river and their channel junction. And Yongdu and Donggye plains are well developed around the Yeongsan riverline, and channel junction of the Yeongsan and Hwangryong rivers in the area, respectively.

• Journal of Fisheries and Marine Sciences Education
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• v.18 no.3
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• pp.209-217
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• 2006

In this study, chemical compositions of Helice tridens tientsinensis(Htt, sea crab) and changes of chemical compositions in fermented sea crab tested according to different storage days(10, 16, 20, 25, 29, 55, 61, 67). The average amount of chemical compositions in raw Htt, it contains 77.12% of moisture, 1.96% of ash, 18.93% of crude protein, 0.26% of crude lipid. During storage time the amount of moisture and crude protein decreased, but crude lipid and ash increased. The amount of volatile basic nitrogen in Htt showed 6.56 mg/100g. The fermented sea crab in brine stored at the temperature of $5^{\circ}C$ showed 23.72 mg/100g of freshness even after 55 days. It showed first stage of decomposition(31.69 mg/100g) after 61 days. it is most efficient to store fermented sea crab at a low temperature. The amount of free amino acid composition in fresh Htt, was measured as follow ;arginine(1140.88 mg/100g), alanine(311.26 mg/100g), prorine(214.63 mg/100g), serine(113.56 mg/100g), taurine(90.80 mg/100g). The amount of amino acid in fermented sea crab increased as the storage days increased. Fatty acid contents in fresh Htt showed the largest amount of erucic acid (27.39 area%) and pentadecenoic acid (19.44 area%), oleic acid (17.68 area%), palmitic acid (11.00 area%), stearic acid (6.89 area%), and elaidic acid (6.15 area%) in order. In fermented sea crab, a small change was noticed in quantity, but the obvious increased composions were palmitoleic and heneicosanoic acid etc.

• Food Science and Preservation
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• v.22 no.1
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• pp.36-43
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• 2015

The edible crab is among the rich resources that can be used as materials for food products, but living crabs and crabs marinated in soy sauce are the only widely utilized materials for food products. For seafood development, research is needed to promote the use of crabs in various products. In this study, the quality changes of fried rice prepared with crab meat, crab emulsion sauce and crab cooker effluent were investigated. The pH and acidity values did not show any significant difference at $-20^{\circ}C$. The acidity of the fried rice continuously increased during storage at 4 and $25^{\circ}C$. The VBN and TBA values of the fried rice stored at 4 and $25^{\circ}C$ were significantly higher than those of the fried rice stored at $-20^{\circ}C$ during the storage period. The viable cell count of the fried rice stored at $-20^{\circ}C$ changed little during the storage period while that of the fried rice stored at 4 and $25^{\circ}C$ rapidly increased over 2 weeks. For the fried rice stored at $-20^{\circ}C$, the overall quality did not show significant differences during the storage period. In conclusion, the best storage temperature for both quality and safety was found to be $-20^{\circ}C$. At such storage temperature, the quality of the stored instant rice using crab meat did not change, and through research the expanding possibilities of using crab materials were confirmed.

• Journal of Life Science
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• v.21 no.9
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• pp.1301-1309
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• 2011

The major function of adipocytes is to store fat in the form of triglycerides. One of the signaling pathways known to affect adipogenesis, i.e. fat formation, is the WNT/${\beta}$-catenin pathway which inhibits the expression and activity of key regulators of adipogenesis. The purpose of this research is to find genes among the WNT/${\beta}$-catenin pathway which regulate adipogenesis by using small interfering (si) RNA and to find the association of single nucleotide polymorphisms (SNPs) of the gene with serum triglyceride levels in the human population. To elucidate the effects of ${\beta}$-catenin siRNA on adipogenesis key factors, PPAR${\gamma}$ and C/EBP${\alpha}$, we performed real-time PCR and western blotting experiments for the analyses of mRNA and protein levels. It was found that the siRNA-mediated knockdown of ${\beta}$-catenin upregulates adipogenesis key factors. However, upstream regulators of the WNT/${\beta}$-catenin pathway, such as DVL2 and LRP6, had no significant effects compared to ${\beta}$-catenin. These results indicate that ${\beta}$-catenin is a candidate gene for human fat accumulation. In general, serum triglyceride level is a good indicator of fat accumulation in humans. According to statistical analyses of the association between serum triglyceride level and SNPs of ${\beta}$-catenin, -10,288 C>T SNP (rs7630377) in the promoter region was significantly associated with serum triglyceride levels (p<0.05) in 290 Korean subjects. On the other hand, serum cholesterol levels were not significantly associated with SNPs of the ${\beta}$-catenin gene. The results of this study showed that ${\beta}$-catenin is associated with fat accumulation both in vitro and in the human population.

• Journal of Life Science
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• v.22 no.10
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• pp.1295-1306
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• 2012

A microorganism producing carboxymethylcellulase (CMCase) was isolated from seawater and identified as Bacillus atrophaeus. This species was designated as B. atrophaeus LBH-18 based on its evolutionary distance and the phylogenetic tree resulting from 16S rDNA sequencing and the neighbor-joining method. The optimal conditions for rice bran (68.1 g/l), peptone (9.1 g/l), and initial pH (7.0) of the medium for cell growth was determined by Design Expert Software based on the response surface method; conditions for production of CMCase were 55.2 g/l, 6.6 g/l, and 7.1, respectively. The optimal temperature for cell growth and the production of CMCase by B. atrophaeus LBH-18 was $30^{\circ}C$. The optimal conditions of agitation speed and aeration rate for cell growth in a 7-l bioreactor were 324 rpm and 0.9 vvm, respectively, whereas those for production of CMCase were 343 rpm and 0.6 vvm, respectively. The optimal inner pressure for cell growth and production of CMCase in a 100-l bioreactor was 0.06 MPa. Maximal production of CMCase under optimal conditions in a 100-l bioreactor was 127.5 U/ml, which was 1.32 times higher than that without an inner pressure. In this study, rice bran was developed as a carbon source for industrial scale production of CMCase by B. atrophaeus LBH-18. Reduced time for the production of CMCase from 7 to 10 days to 3 days by using a bacterial strain with submerged fermentation also resulted in increased productivity of CMCase and a decrease in its production cost.

• Journal of Life Science
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• v.22 no.12
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• pp.1644-1650
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• 2012

The aim of this study was to screen the polymorphisms and distribution of each genotype of insertion/ deletion (indel) markers which were found in a preliminary comparative study of bovine genomic sequence databases. Comparative bioinformatic analyses were first performed between the nucleotide sequences of Bovine Genome Project and those of expressed sequence tag (EST) database, and a total of fifty-one species of indel markers were screened. Of these, forty-two indel markers were evaluated, and nine informative indel markers were ultimately selected for population analysis. Nucleotide sequences of each marker were re-sequenced and their polymorphic patterns were typed in six cattle breeds: Holstein, Angus, Charolais, Hereford, and two Korean native cattle breeds (Hanwoo and Jeju Black cattle). Cattle breeds tested in this study showed polymorphic patterns in eight indel markers but not in the Indel-15 marker in Charolais and Holstein. The results of analysis for Jeju Black cattle (JBC) population indicated an observed heterozygosity (Ho) that was highest in HW_G1 (0.600) and the lowest in Indel_29 (0.274). The PIC value was the highest in HW_G4 (0.373) and lowest in Indel_6 (0.305). These polymorphic indel markers will be useful in supplying genetic information for parentage tests and traceability and to develop a molecular breeding system for improvement of animal production in cattle breeds as well as in the JBC population.

• Korean Journal of Microbiology
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• v.42 no.3
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• pp.185-194
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• 2006

The aim of this study was to identify the bacteria isolated from endodontic lesions by cell culture and to determine the antimicrobial susceptibility of them against 8 antibiotics. The necrotic pulpal tissues were collected from 27 infected root canals, which were diagnosed as endodontic infection. Samples were collected aseptically from the infected pulpal tissue of the infected root canals using a barbed broach and a paper point. The cut barbed broaches and paper points were transferred to an eppendorf tube containing $500{\mu}l\;of\;1{\times}PBS$. The sample solution was briefly mixed and plated onto a BHI-agar plate containing 5% sheep blood. The agar plates were incubated in a $37^{\circ}C$ anaerobic chamber for 2 to 5 days. The bacteria grown on the agar plates were identified by comparison of 16S rRNA gene (rDNA) sequencing method at the species level. To test the sensitivity of the bacteria isolated from the infected root canals against 8 antibiotics, minimum inhibitory concentrations (MIC) were determined using broth dilution assay. The data showed that 101 bacterial strains were isolated and were identified. Streptococcus spp. (29.7%) and Actinomyces spp. (21.8%) were predominantly isolated. The 9 strains were excluded in antimicrobial susceptibility test because they were lost during the experiment or were not grown in broth culture. The percentage of bacteria susceptible for each antibiotic in this study was clindamycin, 87.0% (80 of 92); tetracycline, 75.0% (69 of 92); cefuroxime axetil, 75.0% (69 of 92); amoxicillin + clavulanic acid (5:1), 71.7% (66 of 92); penicillin G, 66.3% (61 of 92); erythromycin, 66.3% (61 of 92); amoxicillin, 44.6% (41 of 92); and ciprofloxacin, 31.5% (29 of 92). The susceptibility pattern of 8 antibiotics was dependent on the host of the bacteria strains rather than the kinds of bacterial species. These results indicate that antibiotic susceptibility test should be performed when antibiotics are needed for the treatment of infected root canals.

• Korean Journal of Microbiology
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• v.53 no.1
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• pp.39-48
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• 2017

In order to evaluate the diversity of microbial population of Korean traditional Deonjang and Gochujang produced in Jeju, Jeonnam, and Jeonbuk province area, microbial communities were analyzed using next generation sequencing. In this result, the dominant bacteria of Deonjang in three area were Bacillus amyloliquefaciens, Tetragenococcus halophilus, and Bacillus was major dominant bacteria in Jeonnam (43.16%) and Jeonbuk (64.54%) area. But in Jeju area, Bacillus was 0.22%, which was significantly different from the other two. Equally, the dominant fungi of Deonjang in 3 area were Candida versatilis. Common fungus in Jeonnam and Jeonbuk area was Candida sp., respectively, 64.22% and 33.68% and Micor sp. was a common fungus in Jeonnam (15.66%) and Jeonbuk area (36.73%). But in Jeju area, Candida sp. and Zygosaccharomyces rouxii were dominant than mold. Bacillus subtilis, Bacillus licheniformis, and B. amyloliquenfaciens were the preminant bacteria in the traditional Gochujang in three regions. But there were no common dominant fungi in the 3 regions. Aspergillus sp. and Rhizopus sp. prevailed in Jeju and Jeonnam region, and Zygosaccharomycess rouxii predominanted in Jeonbuk area. These results suggested that the difference in the samples collected for the study were classified into similar groups according to the characteristics of each sample rather than regional characteristics.