• Microbiology and Biotechnology Letters
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• v.26 no.4
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• pp.275-282
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• 1998

To investigate the increased acid tolerance of a acid-resistant mutant Leuconostoc paramesenteroides P-100 improved as a kimchi starter, proton permeability, ATPase acitivity, glycolysis activity, $Mg^2$sup +/ releasement, and membrane fatty acid composition were studied and comprised with its wild type Leuconostoc paramesenteroides Pw. In the proton permeability experiment, the maximum values of the average half time (t$\_$1/2/) of pH equilibration through the cell membrane of the Pw and the P-100 were about 6.4 min and 7.8 min in 150 mM KCI solution, respectively. In the 3% NaCl solution, the t$\_$1/2/ values of the Pw and the P-100 were 5.5 min and 6.9 min, respectively. The values and pHs of maximal specific activities of ATPase originated from the Pw and the P-100 were 0.5 unit/mg protein and 0.78 unit/mg protein at pH 6.0, respectively. The result of pH dependence of glycolysis showed that the P-100 had higher activities than that of Pw except at pH 7.0. The releases of magnesium from the Pw and the P-100 were observed about 54.5% and 23.2% at pH 4.0 after 2 hours, respectively. The results of comparison of membrane fatty acid composition of the Pw with the P-100 showed that C$\_$8:0/, C$\_$9:0/, C$\_$10:0/, C$\_$11:0/, C$\_$18:0/, and C$\_$19:0,cyclo/ were major different fatty acids between two strains and the content of C$\_$18:1/, and C$\_$19:0,cyclo/ were 2.8%, N.D (not detected) in the Pw and 0.4%, 2.3% in the P-100. These results indicated that acid tolerance of the P-100 was significantly improved in comparison with its wild type Pw.

• Microbiology and Biotechnology Letters
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• v.26 no.2
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• pp.151-160
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• 1998

The Leuconostoc paramesenteroides dominated at refrigeration temperature range was isolated from kimchi, and improved its growth properties by mutation for competitive growth against Lactobacillus plantarum at lower pH. It was found that the minimal pH for the wild type Leuconostoc paramesenteroides Pw growth was pH 4.5 adjusted with HCI and pH 5.0 adjusted with organic-mixture (lactic acid:acetic acid=1:2), respectively. The mutant P-100 could grow in pH 4.0, 4.5, respectively, in MRS broth. Two strains Pw and P-100 were added into kimchi as starter and compared the quality characteristics of kimchi. The total acceptability of Pw and P-100 inoculated kimchi were evaluated better than that of control kimchi (no starter added) by sensory test and extended the optimal pH range of kimchi up to about 2.2, 2.5 times, respectively. In kimchi added P-100, the succinic acid was more abundant than others and the total number of Lactobacillus plantarum was down about 2.5 times in contrast to control kimchi.

• Journal of the Korean Society of Radiology
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• v.17 no.6
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• pp.911-917
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• 2023

The method of observing nodular changes on the liver surface using clinical ultrasonography is useful for diagnosing cirrhosis. However, the speckle noise that inevitably occurs in ultrasound images makes it difficult to identify changes in the liver surface and echo patterns, which has a negative impact on the diagnosis of cirrhosis. The purpose of this study is to model the median modified Wiener filter (MMWF), which can efficiently reduce noise in cirrhotic ultrasound images, and confirm its applicability. Ultrasound images were acquired using an ACR phantom and an actual cirrhotic patient, and the proposed MMWF algorithm and conventional noise reduction algorithm were applied to each image. Coefficient of variation (COV) and edge rise distance (ERD) were used as quantitative image quality evaluation factors for the acquired ultrasound images. We confirmed that the MMWF algorithm improved both COV and ERD values compared to the conventional noise reduction algorithm in both ACR phantom and real ultrasound images of cirrhotic patients. In conclusion, the proposed MMWF algorithm is expected to contribute to improving the diagnosis rate of cirrhosis patients by reducing the noise level and improving spatial resolution at the same time.

• Research in Plant Disease
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• v.30 no.2
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• pp.148-156
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• 2024

Ralstonia pseudosolanacearum, a plant pathogenic bacterium that can survive for a long time in soil and water, causes lethal wilt in the Solanaceae family. Sigma S is a part of the RNA polymerase complex, which regulates gene expression during bacterial stress response or stationary phase. In this study, we investigated the role of sigma S in R. pseudosolanacearum under stress conditions using a rpoS-defective mutant strain of R. pseudosolanacearum and its wild-type strain. The phenotypes of rpoS-defective mutant were complemented by introducing the original rpoS gene. There were no differences observed in bacterial growth rate and exopolysaccharide production between the wild-type strain and the rpoS mutant. However, the wild-type strain responded more sensitively to nutrient deficiency compared to the mutant strain. Under the nutrient deficiency, the rpoS mutant maintained a high bacterial viability for a longer period, while the viability of the wild-type strain declined rapidly. Furthermore, a significant difference in pH was observed between the culture supernatant of the wild-type strain and the mutant strain. The pH of the culture supernatant for the wild-type strain decreased rapidly during bacterial growth, leading to medium acidification. The rapid decline in the wild-type strain's viability may be associated with medium acidification and bacterial sensitivity to acidity during transition to the stationary phase. Interestingly, the rpoS mutant strain cannot utilize acetic acid, D-alanine, D-trehalose, and L-histidine. These results suggest that sigma S of R. pseudosolanacearum regulates the production or utilization of organic acids and controls cell death during stationary phase under nutrient deficiency.

• Korean Journal of Medicinal Crop Science
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• v.12 no.1
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• pp.60-66
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• 2004

This study was carried out to confirm the phylogenetic relationships in Korean Rhus species. Sequences from internal transcribed spacers (ITS) of nuclear ribosomal DNA and rbcL gene of chloroplast DNA were determined. Cotinus coggygria was selected as outgroup because it is closest allied with Rhus in Anacardiaceae. Also, ingroup was limited as six Korean Rhus species. ITS 1 sequences in six species of Rhus and one species of Cotinus ranged from 246 to 253 bp and ITS 2 sequences from 234 to 244 bp. Concerning the G+C content of the studied taxa, ITS 1 sequences ranged from 58.0 to 68.13% and ITS 2 from 59.75 to 68.46%. On the other hand, rbcL sequences were same size in the all species examined by 1,428 bp. G+C contents of rbcL sequences were ranged from 43.56 to 43.77% which means there are nearly no different from interspecies each other. Phylogenetic tree strongly supports the colse relationships between R. succedanea and R. sylvestris. Rhus javanica and Cotinus coggygria were also closely allied with each other in ITS and rbcL trees. Therefore, R. javanica was regarded as most primitive species among the Korean Rhus species. ITS 1 region of nuclear ribosomal DNA was suggested as very useful taxonomical marker for genus Rhus.

• Korean Journal of Plant Taxonomy
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• v.37 no.2
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• pp.131-141
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• 2007

Genetic variation of Ilex cornuta Lindley et Paxton was examined by sequence analyses of ITS for 65 individuals from Korea and China. The length of ITS 1 ranged from 253 to 259 bp. The 5.8S was 159 bp and ITS2 was observed to be 231 bp. A total of 8 different ITS types (Single Nucleotide Polymorphism haplotypes), which showed the difference of 1 - 6 bp, were detected from 65 individuals. The sequence polymorphisms of ITS appeared at 9 different sites. All of four individuals collected at Daejeong-eup in Jeju-do exhibited different types, but all individuals from Naju-si and Muan-gun in Jeollanam-do were identical. The variation of ITS was higher in Jeju-do population than in inland population. Since I. cornuta contains various types of ITS sequences, ITS analyses will provide important information on genetic diversity and conservation of this species.

• The Journal of the Korea Contents Association
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• v.20 no.5
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• pp.585-594
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• 2020

After the launch of Jeju Special Self-Governing Province in 2006, a number of real estate development projects were carried out; the real estate industry has relatively largely grown as compared with other regions since 2011. This growth has slowed down in 2017, along with the increase of unsold houses and the short of its incoming population, causing its real estate market recession. This study analyzed the source of real estate industry growth in Jeju: either affected by national growth power or its regional competitiveness. This study applied Shift-Share Analysis and Growth Differential Analysis, by dividing the recovery period ('06~'10) and expansion period ('11~'16). According to the result, sales amount and the number of employees in the real estate industry in Jeju had grown in the recovery period based on the national growth power. Its regional competitiveness and stable industrial structure grew in the growth period. Development and subdividing of real estate contributed to the growth of the real estate industry in Jeju. On the other hand, management of real estate weakened its market.

• Korean Journal of Plant Taxonomy
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• v.41 no.4
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• pp.338-344
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• 2011

Molecular phylogenetic studies were conducted to evaluate evolutionary trends, relationships and species identities among four species, one variety and one outgroup of the Korean Genus Calystegia. The important characteristics of Calystegia are the shape of the lamina, the length ofthe corolla and the presence of hair. However, many variations were observed as regards the characteristics of the leaf, making true identification difficult. In molecular phylogenetic studies, C. soldanella formed one clade, and it was located mostly in the base. C. hederacea and C. sepium did not form an independent clade in their ITS regions and psbA-trnH regions, and this investigation could not confirm a relationship. Therefore, a relationship between these two species is not sufficiently supported by these markers (ITS and psbA-trnH). Consequently, this research should be achieved through many samples and markers. C. sepium var. japonica and C. dahurica are closely related.

• Journal of Korean Society of Steel Construction
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• v.22 no.1
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• pp.67-74
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• 2010

The cases of collapse of greenhouses in rural areas have been increasing due to the unexpected heavy snow load. Studies on how to prevent the collapse of greenhouses are rare, however, and the damages are repeated annually. This studysuggests two reinforcing methods: the use of ahigh-strength tapered module, and the addition of a pre-tension tie. The high-strength tapered section is installed where the bending moment is maximum. The design of a plastic greenhouse is controlled by its strength rather than its deflection. The shape of a greenhouse resembles that of an arch system, but its actual structural behavior is the frame behavior, because it is non-continually composed of a curved element (a beam) and vertical elements (columns). This system is too weak and slender to resist a vertical load, because an external load is resisted by the moment rather than by axial force. In this study, a new method, the installation of a temporary tie at the junction of the arch and the column only during snow accumulation, is proposed. The tie changes the action of the greenhouse frame to an arch action. The arch action is more effective when the pre-tension force is applied in the tie, which results in a very strong temporary structural system during snowfall. As a result of using this high-strength tapered section, the combined strength ratio of what? decreased from 10% to 30%. In the case of the additional reinforcement with a tie, it was reduced by half.

• Journal of Yeungnam Medical Science
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• v.1 no.1
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• pp.139-144
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• 1984

A case of foregut cyst communicated with esophagus and lined by bronchial mucosa is reviewed and its embryologic base of maldevelopment is discussed. It is not always easy to distinguish between digestive and respiratory cyst in mediastinum. There is whole range of intermediate between a cyst with ciliated and one with squamous or columnar mucosa. Origin of this dysembryoplasia is difficult to determine when one consider that the esophagus is covered with ciliated epithelium until the eleventh week of fetal life and that ciliated growth are found on its wall until the sixth month of the fetal life. And we concluded, general agreement is that cysts which have gastric epithelium in whole or in part, represent a distinct type and should be classified as (gastro) enteric cyst, mediastinal cyst containing cartilage were considered definitely as respiratory(bronchial or bronchogenic) cyst.