• Pediatric Infection and Vaccine
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• v.27 no.2
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• pp.90-101
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• 2020

Purpose: The multiplex reverse transcriptase-polymerase chain reaction (RT-PCR) test developed recently can help detect enteric pathogens of acute gastroenteritis (AGE). This study aimed to investigate the epidemiology of pathogens in children with AGE using the multiplex RT-PCR. Methods: From May 2015 to June 2018, multiplex RT-PCR tests were performed to identify pathogens in the feces of pediatric patients diagnosed with AGE at a secondary hospital in Seoul, Korea. Results: Of the 1,366 stool samples examined for viral pathogens, 483 (35.3%) tested positive for ≥1 pathogen. Group A rotavirus (RV) was detected in 106 cases (7.8%). The positivity rate increased annually from 3.0% (8/263) to 16.7% (48/288) and surged in 2018 (P<0.001). Norovirus (NoV) GII was the most common viral pathogen (263/1,366, 19.3%), and the positivity rate did not increase during the 3 years. Of the 304 stool samples tested for bacterial pathogens, Campylobacter spp. was the most common bacterial pathogen (32/304, 10.5%), followed by Clostridium difficile (22/304, 7.2%) and Salmonella spp. (17/304, 5.6%). The positivity rate of these bacterial pathogens did not change significantly during the study period. Conclusions: NoV GII is the main pathogen in childhood AGE since the introduction of RV vaccine, yet the number of rotavirus-infected patients increased during our study, especially in 2018. Therefore, further research is needed including the possibility of emergence of novel RV strains. Campylobacter spp. is the predominant cause of bacterial AGE in children. For proper treatment, the clinical characteristics of the bacteria should be taken into consideration, and continuous monitoring is necessary.

• Research in Plant Disease
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• v.17 no.2
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• pp.169-176
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• 2011

Phytophthora katsurae is the fungus responsible for chestnut ink disease. The objectives of this study were to determine if a single-strand conformation polymorphism (SSCP) analysis of rDNA-ITS region, elongation factor 1 alpha gene and ${\beta}$-tubulin gene could be used for rapid identification and genetic diversity of P. katsurae, and to assess the potential use of the SSCP technique as a diagnostic tool for P. katsurae. Each regions amplified by PCR using primers designed to overlap the genus Phytophthora were characterized for the Phytophthora species. PCR products were denatured and electrophoresed for SSCP analysis. P. katsurae isolates showed an unique pattern in SSCP analysis and were easily distinguished from other Phytophthora species used as the control. This indicates that SSCP analysis is an useful technique for distinguishing Phytophthora species from genetically close relatives, and show that the SSCP analysis of each region is an efficient detection tool for P. katsurae. But PCR-SSCP analysis of single-gene may have difficulty in distinguishing P. katsurae from other Phytophthora species. Therefore, PCR-SSCP analysis of multi-genes can be useful for rapid and effective identification of P. katsurae.

• Applied Chemistry for Engineering
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• v.24 no.5
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• pp.456-470
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• 2013

Hollow-fiber membranes, is one of the new technologies that is growing rapidly in the past few decades. In addition, separation membranes using polymer materials, have attracted attentions in various fields including gas separation, fuel cells, water treatment, wastewater treatment, and organic separation. Nanofiltration (NF) membranes having the separation characteristics in the intermediate range between ultrafiltration and reverse osmosis (RO) membranes for liquid separation, with relatively low investment cost and operating pressure lower than that of RO membranes, have high permeance and rejection performance of multivalent ions as well as organic compounds of molecular weight between $200{\sim}1000gmol^{-1}$. In this paper, we would like to review the research trends on the various structure control and characterization of NF hollow fiber membranes with respect to materials and the methods of preparation (phase inversion method and interfacial polymerization method). Currently, most of NF membranes have been manufactured by plate and frame types or spiral wound types. But hollow fiber types have delayed in commercial products, because of the weak strength when to produce on the basis of the existing materials, therefore the development of new materials or improvement of existing materials will be needed. If improving manufacturing technology is available, hollow fiber types will replace spiral wound types and gradually show a higher market share.

• Asian Journal of Turfgrass Science
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• v.25 no.2
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• pp.147-152
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• 2011

This study was conducted to evaluate the growth characteristics of creeping bentgrass cultivars for fairway of golf course at Yeoju area in Korea. At germination and coverage rate of creeping bentgrass, 'Shark' and 'CY-2' were excellent, 'L-93', 'Alpha', 'T-1 was in order', respectively. Visual qualities of 'Shark' and 'CY-2' also were excellent. Especially, 'Shark', 'T-1', and 'CY-2' showed excellent visual quality in summer days, the critical times for the bentgrass fairway quality. 'Shark', 'CY-2' and 'T-1' were excellent in Chlorophyll contents throughout the evaluation period. Chlorophyll content of 'T-1' was maintained very high in summer. 'CY-2' and 'Shark' showed the best root growth at the beginning of the study and contained longer and hairy roots. Which might make these two cultivars' water absorption easier than other's. NDVI (normalized difference vegetation index)of 'Shark', 'L-93' and 'CY-2' was excellent, respectively. 'T-1' showed the highest density and 'Shark', 'CY-2', 'Alpha', 'L-93' was followed by. The density of 'T-1' was rather increased in summer season, while those of other cultivars were decreased. Three diseases such as anthracnose, brown patch, and dollar spot, were appeared during the evaluation period. 'T-1' and 'L-93' were very sensitive to anthracnose which occurred at the beginning days of the study. The most susceptible cultivars to brown patch were 'Alpha' and 'L-93'. 'T-1' was the least resistant to dollar spot which occurred at the same time with brown patch.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.8
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• pp.3731-3740
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• 2012

Background: There have been few studies of Asian ovarian cancer and benign tumors. The primary aim of this paper was to report the protocol of the Ko-EVE study to examine epidemiological and molecular factors for ovarian cancer and benign neoplasms and to ascertain the major risk factors for ovarian cancer control in Korea. Methods: This case-control study covers incident epithelial ovarian cancers and benign neoplasms, four major centers participating in enrolling incident cases and 3 hospitals enrolling healthy controls among health examinees. Standardized questionnaires were administered by trained interviewers, including sections on socio-demographics characteristics, past medical history, medication usage, family history, lifetime consumption of alcohol and tobacco, diet, physical activity, and reproductive factors for women. Various biological specimens were collected in the biorepository according to the standardized protocol. Annual follow-up for cancer cases and follow-up at the 1st year for benign tumor cases are performing to evaluate treatment effect and progression. Passive follow to see long-term survival will be conducting using record linkage with national data. Results: The total number recruited in 2010-2011 was 246 epithelial ovarian cancer cases, 362 benign epithelial tumors and 345 controls. We are planning to collect subjects for at least 1,500 sets of ovarian cancer, 2,000 benign tumors and 1,500 controls till 2018. Conclusions: The Ko-EVE will provide unique and important data to probe the etiology and natural history of Korean epithelial ovarian cancer. It will be continued by genomic and proteomic epidemiological analyses and future intervention studies for the prevention of ovarian cancer among Koreans.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.11
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• pp.6715-6719
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• 2013

Objective: To explore the incidence, clinical characteristics, diagnosis and treatment strategies, prognosis of patients with malignancy-associated hypercalcemia (MAH). Methods: The data of 115 patients with MAH who were treated at the Medical Oncology Department of Chinese PLA General Hospital from Jan., 2001 to Dec., 2010 was retrospectively reviewed. Survival analysis was performed using the Kaplan-Meier method and the Cox proportional hazard model with statistic software SPSS 18.0. Results: The patients had blood calcium levels ranging from 2.77 to 4.87 mmol/L. Except for 9 cases who died or were discharged within 5 days after admission, all other patients recovered to normal blood calcium level after treatment with bisphosphonates or intravenous hydration and diuretics; their survival after occurrence of MAH was from 1 day to 4,051 days, and the median survival time was only 50 days. In the log-rank test, the male, renal metastasis, central nervous system symptoms and hypercalcemia occurring over 140 days after cancer diagnosis were predictors of poor survival (P=0.002, P=0.046, P=0.000, P=0.009). In the COX analysis, being male, central nervous system symptoms and hypercalcemia lasting over 140 days after cancer diagnosis were independent prognostic factors for survival time (RR=2.131, P=0.027; RR=3.054, P=0.002; RR=2.403, P=0.001). According to these factors, a score system was established to predict the patient prognosis and adjust the treatment. Conclusion: Cancer patients with MAH have an extremely poor median survival. Some independent factors indicate poor prognosis, including male gender, central nervous system symptoms and hypercalcemia lasting over 140 days after cancer diagnosis. The prognostic score can serve as a reference for MAH prognosis and treatment, worthy of further investigation.

• Korean Journal of Ichthyology
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• v.29 no.1
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• pp.1-12
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• 2017

A natural hybrid of interspecific between the Coreoleuciscus splendidus and C. aeruginos (Cypriniformes: Cyprinidae) was captured in the Hwang-ji Stream, a tributary of the Nakdong River basin in Korea. An interspecific hybrid between C. splendidus and C. aeruginos was genetically identified based on morphological characteristics and the sequence analysis of nuclear recombination activating gene 1 (RAG1) gene (1,334 bp) and mitochondrial cytochrome c oxidase subunit 1 (CO1) gene (1,551 bp). As a result of morphological variations, the natural hybrid appeared to have an intermediate character between two parental species (C. splendidus and C. aeruginos) in three variations of black array (s) on dorsal, caudal and anal fin rays. Phylogenetic analysis inferred from RAG1 and CO1 sequence data revealed that Coreoleuciscus populations from Hwang-ji stream consist of two pure Coreoleuciscus species and a hybrid individual group. The individuals were clearly identified the cross and reciprocal hybrid by CO1 gene analysis. In RAG1 gene, 13 nucleotide variation loci were detected and the hybrid individuals displayed the double peaks of sequence chromatograms at the 9 diagnostic positions. In this study, molecular data and morphological variations were clearly demonstrated that hybridization did occur between C. splendidus and C. aeruginos. However, F2 hybrid generation and reproductive capacity of F1 hybrid individuals were not demonstrated.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.227-227
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• 2017

This study was conducted to analyze the reduction of quality and ripening rate of rice due to submergence during ripening stage and identify the physiological cause. Korean japonica type rice cultivars, Nampyeong was used in the experiment. The following 7, 14 day after heading, they were then moved into submergence treatment facility and we conducted the tests under three different submergence conditions - T1(clear water and overhead submergence), T2(Muddy water and exposure of Flag leaf end ), T3(Muddy water and overhead submergence), and the treatment lasted for 4days. The decrease of ripening rate was most severe in T3 treatment at 7days after heading, and the decrease of head rice ratio was most severe in T3 treatment at 14days after heading. Meanwhile the starch synthesis was inhibited, as the supply of assimilation products was inhibited in grain during the submergence treatment. And in stem, sucrose content was increased because the soluble carbohydrates accumulated before heading were decomposed. These changes may be due to the consumption of respiratory substrate in anaerobic conditions and the inhibition of the production of photosynthetic products by light interception. In order to see what kind of reaction occurs at the molecular level, we examined the degree of RNA expression in grain, stem and leaf. First, the expression of rna associated with starch synthesis in grain was decreased in all submergence treatment. and especially Ospul(DBE) was more decreased in 14days after heading treatment than 7days after heading treatment. This difference can explain the result that the decrease of head rice ratio was more severe at 14days after heading. And in stem, the expression of rna associated with the supply of assimilation products was decreased in submergence treatment. Finally in leaf, the expression of rna(ADH, ALDH) associated with anaerobic respiration was increased, while the expression of rna associated with photosynthesis was decreased. These results of physiological analysis can used to develop the cultivation technique and to offer the information for breeding the cultivars with tolerant characteristics to submergence stress during ripening stage in rice.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.215-215
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• 2017

The preference for domestic cereal crop of Setaria Italica has been increased with the recent interest in healthy foods. However, the productivity of Korean domestic produce, which has been decreasing due to the lack of cultivation technology and the low rate of mechanization during cultivation. Increase of germination ability will have a positive effect on the cultivation by reducing the labor of the manpower consuming and weeding work. Therefore, red light, ultrasonication, liquid priming and liquid smoke treatment that are effective for the germination of the seeds evaluated. The seeds of 1.4mm or more were used for the experiment. The priming solution used in the experiment was 1% $KH_2PO_4$ (74mM). During the priming, the light treated seeds at 2000 lux for 15, 30, 60 and 120 minutes. Ultrasonicationd treatment was performed for 5, 10, and 20 minutes at exposures of 60%, 80%, and 100% of ultrasound up to 21.6 kHz during priming. Light or ultrasound treated seeds transferred to priming treatment at $15^{\circ}C$ for 24 hours. The treatment of the liquid smoke was divided into the treatment of the liquid smoke alone and the treatment of the liquid smoke with the priming. The liquid smoke alone was diluted with distilled water without priming solution and the treatment of the liquid smoke was diluted with the salt priming solution. Both treatments were performed at 0.0%, 0.5%, 1.0%, 5.0%, and 10.0% of the liquid smoke (pH7) concentration at $15^{\circ}C$ for 6 hours. After each treatment, the seeds were dried to moisture content ranged 5-8% at $25^{\circ}C$ for 24 hours. All treatments showed better results than the non-treated control. Light treatment for 120 minutes improved for germination percentage (GP), Germination uniformity (GU) and heath seed percentage (HS). Ultrasonication treatment was most effective when treated with ultrasound at 21.6 kHz for 5 minutes in all germination characteristics. Ten % of the liquid smoke increase in 92% GP, 1.8 days MGT, $54%{\cdot}day^{-1}GR$, 0.76 GU and 88% HS comparing to non-treated control (72% GP, 2.3 days MGT, $45%{\cdot}day^{-1}GR$, 1.48 GU, and 63 % HS). This study showed that it is possible to obtain high germination by adding liquid smoke treatment to the seeds supplied to the farmers. The efficacy of light, ultrasonication, inorganic salt priming, and liquid smoke treatment on the seeds found in the experiment will be a positive alternative to labor force problems in the cultivation by improving germination.

• Korean Journal of Environmental Biology
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• v.37 no.2
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• pp.119-128
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• 2019

The morphological characteristics of the bloom-forming dinoflagellate Akashiwo sanguinea isolated from Jangmok Harbour, Geoje in Korea was examined using light and scanning electron microscope (SEM), and its large subunit (LSU) rDNA was sequenced. Additionally, investigation was done on the effects of temperature and salinity on the growth of A. sanguinea. The cells were dorso-ventrally compressed up to 54.7-70.3 ㎛ long and 31.5-48.5 ㎛ wide. The epicone was conical while the hypocone was separated into two lobes. The nucleus was positioned at the center of the cell. The yellow-brown chloroplasts radiated close to the cell center. SEM observation indicated that A. sanguinea has an e-shaped apical groove. Molecular phylogeny based on LSU rDNA gene sequences revealed that the A. sanguinea strains isolated from Jangmok Harbor were classified in the clade of ribotype A. The maximum growth rate (0.50 day^-1) was observed at 20℃ and 20 psu, while the maximum cell density (1,372 cells mL^-1) was observed at 25℃ and 30 psu. This indicates that the blooms of A. sanguinea ribotype A in Korean coastal area are affected by water temperature, rather than the salinity.