• Korean Journal of Environmental Biology
• /
• v.30 no.1
• /
• pp.39-46
• /
• 2012

The distributions of phytoplankton community are investigated from 29 reservoirs in Yeongsan and Seomjin River Basins, Korea. As a microalgal flora, a total of 424 species of phytoplankton were identified. They were 157 Chlorophyceae, 161 Bacillariophyceae, 39 Cyanophyceae, and 67 other algal taxa. The phytoplankton diversity were low in stream type reservoirs such as Kumho, Youngsan and Youngam Reservoirs. The population density of phytoplankton ranged from 29 cells $mL^{-1}$ to 53,161 cells $mL^{-1}$. The dominant phytoplankton species more than 20% of total standing crops were $Asterionella$ $formosa$, $Aulacoseira$ $ambigua$, $Aulacoseira$ $distans$, $Aulacoseira$ $granulata$, $Cyclotella$ sp., $Synedra$ $acus$, $Coelastrum$ $reticulatum$, $Pandorina$ $morum$, $Scenedesmus$ $arcuatus$, $Aphanothece$ $clathrata$, $Microcystis$ $aeruginosa$, $Phormidium$ sp. The concentration of chlorophyll $a$ ranged from 0.41 mg $m^{-3}$~220.72 mg $m^{-3}$, and showed highest concentration in Gaecho-je. The concentrations of TN and TP have no clear relationships with chlorophyll $a$ concentrations.

• Korean Chemical Engineering Research
• /
• v.47 no.4
• /
• pp.465-469
• /
• 2009

Characteristics of oxidation reaction of four lanthanide chlorides(Ce, Nd, Pr and $EuCl_3$) in a oxygen-eutectic(LiCl-KCl) salt bubble column was investigated. From the results obtained from the thermochemical calculations by HSC chemistry software, the most stable lanthanide compounds in the oxygen-used rare earth chlorides system were oxychlorides(EuOCl, NdOCl, PrOCl) and oxides($CeO_2$, $PrO_2$), which coincide well with results of the Gibbs free energy of the reaction. In this study, similar to the thermochemical results, regardless of the sparging time and molten salt temperature, oxychlorides for Eu, Nd and Pr and oxides for Ce and Pr were formed as a precipitant by a reaction with oxygen. The structure of the rare earth precipitates was divided into two shapes : small cubic(oxide) and large tetragonal (oxychloride) structures. The conversion efficiencies of the lanthanide elements to their molten salt-insoluble precipitates(or compound) were increased with the sparging time and temperature, and Ce showed the best reactivity. In the conditions of $650^{\circ}C$ of the molten salt temperature and 420 min of the sparging time, the conversion efficiencies were over 99% for all the investigated lanthanide chlorides.

• Journal of Life Science
• /
• v.23 no.8
• /
• pp.1032-1040
• /
• 2013

The comparative effects of fibrinolytic, antioxidative activity and electrophoretical protein patterns with Cordyceps militaris powder (CM) and cordycepin-enriched Cordyceps militaris JLM0636 powder (CCM) and fermented cordycepin-enriched Cordyceps militaris JLM0636 powder by several microscopic organisms were investigated. In addition, nutritional materials such as mineral, protein, and fatty acids were also measured. The protein concentration was higher in CCM than that in CM. The protein concentration in fermented CCM was the highest in CCM treated by Aspergillus kawachii among the various samples. When total protein patterns of CM, CCM, and both fermented CCMs were analyzed by native- and SDS-PAGE, there were slightly varietal differences in electrophoretical protein patterns. Major minerals were K, Ca, Mg, and Zn. Major fatty acids were palmitic acid, stearic acid, oleic acid, linoleic acid, and linolenic acid. Fibrinolytic activity was the highest in the fermented CCM by Bs treatment among the various samples. The ${\alpha},{\alpha}^{\prime}$-diphenyl-${\beta}$-picrylhydrazyl (DPPH) radical scavenging activity was slightly stronger in the CCM treated with Aspergillus kawachii among the various samples; however, these samples all exhibited relatively low levels of activity compared with the butylated hydroxytoluene (BHT). These results may provide the basic data necessary to understand the biological activities and chemical characteristics of Cordyceps militaris JLM0636 powder fermented by several microscopic organisms to develop functional foods.

• Journal of radiological science and technology
• /
• v.39 no.3
• /
• pp.329-336
• /
• 2016

The purpose of this study was to evaluate the usefulness of low-dose CT (LDCT) for emphysema compared with high-resolution CT (HRCT). Measurements of radiation dose and noise were repeated 3 times in same exposure condition which was similar with obtaining HRCT and LDCT images. We analysed reading results of 146 subjects. Six images per participants selected for emphysema grading. Emphysema was graded for all 6 zones on the left and right sides of the lungs by the consensus reading of two chest radiologists using a 4-point scale. Between the HRCT and LDCT images, diagnostic differences and agreements for emphysema were analyzed by McNemar's and unweighted kappa tests, and radiation doses and noise by a Mann-Whitney U-test, using the SPSS 19.0 program. Radiation dose from HRCT was significantly higher than that of LDCT, but the noise was significantly lower in HRCT than in LDCT. Diagnostic agreement for emphysema between HRCT and LDCT images was excellent (k-value=0.88). Emphysema grading scores were not significantly different between HRCT and LDCT images for all six lung zones. Emphysema grading scores from LDCT images were significantly correlated with increased scores on HRCT images (r=0.599, p < 0.001). Considering the tradeoff between radiation dose and image noise, LDCT could be used as the gold standard method instead of HRCT for emphysema detection and grading.

• Parasites, Hosts and Diseases
• /
• v.33 no.1
• /
• pp.27-36
• /
• 1995

Comparative epidemiological studies on vector reservoir animals of tsutsugamushi disease were carried out in between south coast (the highest endemic) areas and east coast flow endemicl areas in October 1993. Fauna of field rodents and their population densities were not different between two areas. Antibody positive rate of Apodemus agrarius sera was higher in east coast (43.2% in south coast and 63.6% in east coast). High correlation (r = 0.87) was shown between antibody positive rate of A. osrwiur sera and population density of the vector mites (Leptotrombidium scutellare and 1. pnllidunl). L. scutellare was predominant in south coast, showing 110.6 chigger index (74.9% of the total chiggersl , whereas L. pcllidum was predominant in east coast, showing 126.3 chigger index (60.4% of the total). As higher population density of 1. scutellare was found in south coast where the prevalence rate of tsutsugamushi disease is the highest, it is believed that L. scutellare is more important vector species than L. pallidum which may result from more frequent vector-human contact.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.34 no.5
• /
• pp.593-598
• /
• 2005

Antithrombosis and antioxidant activity of the methanol extracts, which were prepared from 51 different brands of rice, were evaluated to investigate bioactive-substances. Among them, the extract of sample No. 2, 25, 40 and 41 showed strong thrombin inhibition activities ($401\~764\%$ inhibition at 5 mg/mL), and the extract of sample No. 5, 9, 23, 36, 44 and 48 showed strong DPPH scavenging activities ($40.8\~64.1\%$ at 0.4 mg/mL), respectively. The average contents of total flavonoid and polyphenol with 50 brands of rice were 51.89 mg/kg and 195.23 mg/kg, respectively. However, the activities were not linked with the contents of flavonoid and polyphenol. By the treatment at $100^{\circ}C$ for 10 min, the activities of the selected rices were severely decreased. Maximal remaining activities of antithrombosis and antioxidant were $208\%$ of No. 40 and $23.2\%$ of No. 48, respectively. These results support a functional superiority of rice-based livelihood, and suggest that the development of healthy food using functional ingredients of rice is possible.

• Korean journal of applied entomology
• /
• v.39 no.1
• /
• pp.31-41
• /
• 2000

Community analysis of oribatid mites was conducted in Namsan and Kwangreung coniferous forests which have been received by different degrees of environmental pressures through urbanization processes. Oribatid mites were sampled in the litter and soil layer of study sites from May 1993 to October 1994. Although two sites have been under similar weather condition, seasonal changes in oribatid mites density did not show a synchronized pattern. Density in spring and summer showed stable pattern with low fluctuations, but unstable pattern in autumn between 1993 and 1994. And these patterns were highly correlated with precipitation. The density and species number were higher in the litter layer than in the soil layer and showed no typical seasonal changes. The dominant species were Scheloribates latipes (1 l.78%), Pergalumna altera (8.92%), Eohypochthonius crassisetiger (7.58%), Scheloribates sp. (6.89%) and Suctobelbella yezoensis (5.04%) in Namsan, and Ceratozetes japonicus (25.72%), Punctoribates punctum (14.15%), Trichogalumna nipponica (10.96%) and Ramusella sengbuschi (5.08%) in Kwangreung. The number of species with high constany were 10 and 18 in Namsan and Kwangreung, respectively. Namsan showed the feature of urban forests. In analysis of species diversity, species richness was significantly higher in Kwangreung than in Namsan, while shannon (H') and evenness index (J') were higher in Namsan than in Kwangreung. The values of shannon index (H') in Namsan and Kwangreugn were 2.83 and 2.62, respectively and evenness index (J') were 0.78 and 0.67, respectively. The value of similarity index between two sites was 0.68.

• Journal of Korea Foresty Energy
• /
• v.21 no.3
• /
• pp.34-45
• /
• 2002

This study was carried out to investigate the diversity and frequency of ectomycorrhizal fungi by cutting levels in Quercus acuta and Pinus densiflora stands from June to October, 2001. The obtained results from investigation were as follows, 1. The total of fungi found during the surveyed periods were 50 species, 30 genus, 15 families. The fungi belonged to Agaricales(37 species, 18 genus, 7 families), Aphllophorales(7 species, 6 genus, 3 families), Auriculariales(1 species, 1 genus, 1 families) and Gasteromycetes(5 species, 5 genus, 4 families), Basidiomycota. 2. The total number of putative ectomycorrhizal fruiting bodies were 137 individuals, 22 species, 10 genus, 5 families, 79 individuals, 10 species, 6 genus, 3 families at strip-cutting area of Pinus densiflora stand, 24 individuals, 9 species, 5 genus, 4 families at strip-cutting area of Quercus acuta stand and 25 individuals, 10 species, 4 genus, 3 families at spacing cutting area of Quercus acuta stand. 3. Tylropilus neofelleus had high host specificity associated with Chamaecyparis obtusa, while Amanita pseudoporphyria had relatively wide host ranges compared to other ectomycorrhizal fungi. 4. The results analyzed by Correlation coefficients showed that relative humidity and precipitation were major enviromental factors to affect the distribution of ectomycorrhizal fruiting bodies.

• Applied Biological Chemistry
• /
• v.51 no.1
• /
• pp.55-59
• /
• 2008

The composition of essential oil from the aerial part of Erigeron canadensis L. was analyzed by GC-MS. Thirty-one constituents were identified from the essential oil: eighteen hydrocarbons (91.99% of the total oil), two acetates (2.92%), three alcohols (3.59%), four ethers (0.49%), one aldehyde (0.05%), and three ketone (0.23%). Major constituents of the essential oil were D,L-limonene (68.25% of the total oil) and delta-3-carene (15.9%). The $IC_{50}$ value of the essential oil was 0.027 ${\mu}g$ $mg^{-1}$ in MTT assay using HaCaT keratinocyte cell line.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.41 no.3
• /
• pp.83-92
• /
• 2004

Gene expression profile is numerical data of gene expression level from organism measured on the microarray. Generally, each specific tissue indicates different expression levels in related genes, so that we can classify cancer with gene expression profile. Because not all the genes are related to classification, it is needed to select related genes that is called feature selection. This paper proposes a new gene selection method using forward selection method in regression analysis. This method reduces redundant information in the selected genes to have more efficient classification. We used k-nearest neighbor as a classifier and tested with colon cancer dataset. The results are compared with Pearson's coefficient and Spearman's coefficient methods and the proposed method showed better performance. It showed 90.3% accuracy in classification. The method also successfully applied to lymphoma cancer dataset.