• Korean Journal of Bronchoesophagology
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• v.2 no.2
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• pp.200-212
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• 1996

The clinical staging systems for oral squamous cell carcinoma is limited as a prognostic indicatior because of different biological characteristics of cancer in this region and variable microenvironment depending on subsites, there have been study to determine prognosis by evaluating malignancy, that is the nature of tumor cells. Many studies have been tried to determine prognostic indicator in various malignancies for the evaluation of differentiation capacity and the expression of oncogene product. EGF make a role in cellular growth and differentiation and to be essential in cellular survival. EGFR is an intergral membrane protein, stimulate cellular differentiation and hormonal secretion, and has structural homology with V-erb-B transforming protein. Recent reports have demonstrated that EGFR is overexpressed in stomach, breast, vagina, dermis, head and neck, genitourinary and lung tumors, and possibly used as a tumor marker. In head and neck region, most of studies were mainly carried out on laryngeal squamous cell carcinoma. In the present study, immunohistochemical study for EGFR and C-erb-B2 gene in paraffin sections of 45 squamous cell carcinoma in oral cavity was performed to evaluate the presense of EGFR and C- erb-B2 gene in this lesion, to evaluate them as a prognostic indicator by analysing the correlation between these expression and subsites, primary stages, clinical stages, pathologic grades, neck node metastasis, recurrences and treatment results, and to determine relation between EGFR and C-erb-B2 gene.

• The Journal of the Korean Society for Microbiology
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• v.35 no.3
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• pp.225-237
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• 2000

Vibrio vulnificus, a halophilic vibrio is an estuarine gram-negative bacteria that is associated with severe and frequently fatal wound infections and life-threatening septicemia. Bacteriocins are defined as antibacterial substance produced by various species of bacteria which are usually active against closely related organisms. Bacteriocins have found widespread application in epidemiological studies as specific markers of bacteria. It was proposed by Ha et al. (1990. J. Korean. Soc. Microbiol. 25: 586.) to give the bacteriocins produced by V. vulnificus the name "vulnificins". In the present study, a total of 72 strains of V. vulnificus isolated from patients and oysters were subjected to screen potential producers and indicators of vulnificin, applying ultraviolet induction method. Sensitivity of several strains of Serratia marcesans, Pseudomonas aeruginosa, Shigella flexneri, Salmonella typhi and Yersinia enterocolitica to vulnificins were also examined out. All the tested strains of V. vulnificus produced vulnificins active against indicator strains with various different inhibitory patterns. The spectrum of vulnificin activity and sensitive spectrum of indicator strains were considerably broad. Interestingly, almost all strains of S. marcescens, P. aeruginosa, Salmonella sp., Shigella sp. and Y. enterocolitica tested were sensitive to 1-7 vulnificin(s). Taken together, the present study demonstrated that all of the isolates of V. vulnificus produced vulnificins and that 8 good vulnificin producers and 10 good indicators were detected. These strains can be employed efficiently for establishing vulnificin typing scheme of V. vulnificus and for the detection of bacteriocinogeny and sensitivity in V. vulnificus. Biological role of vulnificin remains to be further elucidated.

• Journal of Microbiology and Biotechnology
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• v.14 no.2
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• pp.290-296
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• 2004

The effects of potassium, sodium, calcium, magnesium, and iron on cyanobacterial bloom potentials were investigated in Daechung Reservoir, Korea. Potassium showed the highest correlation with the cyanobacterial cell number (r=0.487, P<0.05) and phycocyanin concentration (r=0.499, P<0.05). However, it was not likely that the potassium had directly affected the bloom formation, because the variations of its concentration were not significantly large. In contrast, the Fe concentration fluctuated drastically and exhibited a negative correlation with the cyanobacterial cell number (r=- 0.388, P<0.1) and phycocyanin concentration (r=-0.446, P<0.05). Accordingly, the K:Fe atomic ratio would appear to reflect the extent of cyanobacterial bloom more precisely than K or Fe alone. The K:Fe ratio specifically correlated with cyanobacterial percentage, the cyanobacterial cell number and phycocyanin concentration (r=0.840, P<0.001; r=0.416, P<0.05; r=0.522, P<0.01, respectively). With the K:Fe atomic ratio of over 200, the chlorophyll-a concentration, cyanobacterial cell number, and phycocyanin concentration exceeded $10\mu$g $1^{-1}$20,000 cells $ml^{-1}$, and 20 pM, respectively, the general criteria of eutrophic water.

• Journal of Korean Society on Water Environment
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• v.26 no.1
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• pp.10-18
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• 2010

Water quality and the distribution of ammonia oxidizing bacteria were characterized in constructed wetland of Shihwa lake. Both physico-chemical parameters and fecal indicator microorganisms including total coliforms, E.coli, Enterococcus spp. were measured. In addition, denaturant gradient gel electrophoresis (DGGE) was carried out after PCR amplification of amoA gene from input, output, and wetland sites of the Banwol, Donghwa, and Samhwa stream in Shihwa lake area. Physico-chemical parameters were in proper range for typical nitrifying bacteria to grow and perform their biological activities. Average concentrations of fecal indicator microorganisms of wetland samples were lower than those of input sites. These results suggested that microbial water quality improved by the process of constructed wetland. According to phylogenetic information obtained from DGGE from study sites, distribution of nitrifying bacteria from each of input, output, and wetland were generally distinctive one another. In addition, distribution of nitrifying bacteria between Banwol and Donghwa streams showed higher similarity (52.6%) than this of Samhwa stream (15.2%). These results indicated that characteristics of ammonia oxidizing bacteria in Samhwa were unique in comparison with those of Banwol and Donghwa stream.

• Economic and Environmental Geology
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• v.30 no.3
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• pp.223-230
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• 1997

The skeletal chemistry of calcareous microfossils may contribute to the classification of various biological processes and be used as an environmental indicator for future pollution. In order to examine the degree of heavy metal pollutions in marine environments, samples of sediment and benthonic foraminifera were taken from 5 study areas from 3 different stations in coastal offshore regions of Korea. After sieving, cleaning and acid digestion, sample were analyzed for heavy metals by ICP-MS, ICP-AES and AAS. Concentrations of Cd, Cu, Pb and Zn in most of marine sediments from 5 study areas are not higher than those in sediments from unpolluted marine environment in the U.K.. However, pollution indices are up to 0.96~0.99 in the Gwangyang and Yulchon areas which are classified as the special control distric along the coast for pollution. The pollution indices decrease in order of Yulchon > Gwangyang > Mokpo > Gamak = Yoja > Yonggwang areas. Concentrations of Mg, Pb, Sr and Zn in Ammonia beccarii Pseudorotalia gaimardii, Quinqueloculina lamarckiana are reduced after pre-treatment of samples. From the result of bioconcentration index, Mg is easily accumulated in microfossils and Quinqueloculina lamarckiana may be used as the best indicator for future pollution.

• Korean Journal of Environment and Ecology
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• v.24 no.1
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• pp.78-86
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• 2010

The classification of biotope type in major Korean cities was made based on the land use concept rather than the ecological concept of the land as the habitat of biological communities. Therefore, biotope type need to be reclassified according to ecological concerns and regional characteristics. This study attempts to clearly define various critical concepts regarding the classification of biotope type, such as classification hierarchy, classification criteria, classification factor, classification indicator, classification key, and classification standard. Furthermore, it also attempts to suggest the ways to improve the classification system of biotope type by sampling the cases of major Korean cities. The classification system of biotope type is required to have a coherent system that provides basic guidelines, standards and hierarchy with regard to biotic, abiotic and anthropotic factors, as well as classification indicators and classification keys.

• Food Science and Biotechnology
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• v.16 no.1
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• pp.99-103
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• 2007

The purpose of this study was to develop a simple detection method, possibly at the species-level, that allows for large-scale screening of bifidobacteria. Human fecal samples were plated on MRS-raffinose agar containing cysteine and neomycin sulfate, serving as selective pressure for bifidobacteria, and 0.003%(w/v) bromocresol green. All of the test strains grew well on this medium at $37{\pm}1^{\circ}C$, forming white colonies surrounded by yellow halos, which presented a sharp contrast against the green background. In this disc assay, the required incubation time to develop a yellowish zone varied with the species of Bifidobacterium that was tested, allowing for differential counts and easy identification at the species-level: 10-14 hr for B. bifidum, 20-22 hr for B. catenulatum and B. infantis. and 24-25 hr for B. longum and B. breve. No apparent color was observed for B. angulatum and B. adolescentis 28 hr after inoculation. To evaluate the results of pH indicator-based identification, individual isolates were subjected to a colony-PCR experiment with genus-specific primers. The amplified products from the isolates were in good accordance with those from the reference strains at a level of 95% agreement. These results suggest that the present method could be conveniently applied to cell counts, as well as to the preliminary identification of bifidobacteria from a variety of sample types including human feces, dairy products, and commercial probiotic supplements.

• Journal of Food Hygiene and Safety
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• v.32 no.6
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• pp.500-506
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• 2017

Kimchi cabbage is one of the four major vegetable crops in Korea. The total annual production of kimchi cabbage, the main material of kimchi, was 20,559 tons in 2015. Kimchi cabbage is one of the majer crops produced by farmers which accounts for about 80% of the total leaf vegetable production in Korea. As the consumption of environmental-friendly agricultural products increases, food safety is one of the major public health concerns. We analyzed the biological hazards of kimchi cabbage produced by two types of cultivation methos such as organic farming and conventional farming using various culture media and microscopy. A total of 432 samples were analysed for presence of sanitary indicator microorganisms (aerobic plate count, coliform count, yeast & mold) and food-borne pathogens (Staphylococcus aureus, environmental Listeria, Bacillus cereus). The population of sanitary indicating microorganisms and food borne pathogens was under 5 Log CFU/g in all tested samples. The results of total microorganism numbers of leaf surface showed a positive correlation to those of soil samples. Additionally, we examined chemical factors such as pesticide residues and heavy metals in soil samples. All tested samples did not shown contamination levels higher than the standard limit.

• Korean Journal of Ornithology
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• v.25 no.2
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• pp.106-111
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• 2018

The Black-tailed gull (Larus crassirostris) is one of the most common gull species in the Northeast Asia and classified as LC (least concern) in the IUCN Red List. The bird has become a useful indicator for marine environmental pollution and habitat disruption, since the human activities impacted marine environments. Here we show that the black-tailed Gull has 6 haplotypes and some rare haplotypes are locally limited implying that the bird may not disperse far. This study may be the first report on population genetic study of Black-tailed Gull in Korea and could be used as the baseline data for monitoring and genetic study on the bird as an environmental indicator.

• Korean Journal of Plant Resources
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• v.35 no.1
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• pp.109-133
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• 2022

We investigated the flora of Gwanmae island and discussed important vascular plants found on the island. We made plant list using voucher specimens collected from Gwanmae island from 2016 to 2021 and deposited in CNU. There are 500 taxa in Gwanmae island, comprising 103 families, 307 genera, 461 species, 4 subspecies, 32 varieties and 3 forms. Eight endemic plants of Korea were found including Saussurea polylepis Nakai. There are 15 red list plants designated by Ministry of Environment including Cleisostoma scolopendrifolium (Makino) Garay and Woodwardia japonica (L. f.) Sm. There are total 126 taxa of floristic regional indicator plants including 4 taxa of level V such as Juniperus procumbens (Siebold ex Endl.) Miq., 4 taxa of level IV such as Wisteria japonica Siebold & Zucc., 45 taxa of level III such as Rubus trifidus Thunb., 16 taxa of level II such as Glehnia littoralis F. Schmidt and 56 taxa of level I such as Carpesium glossophyllum Maxim. There are 32 invasive plants including Cerastium glomeratum Thuill.