82 results on '"Seo DJ"'
Search Results
2. Hydrogen production with integrated microchannel fuel processor using methanol for portable fuel cell systems
- Author
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Park, GG, Yim, SD, Yoon, YG, Kirn, CS, Seo, DJ, and Eguchi, K
- Subjects
fuel processor ,microchannel reactor ,hydrogen production ,portable fuel cells ,methanol combustor ,methanol steam reformer - Published
- 2005
3. Hydrogen production with integrated microchannel fuel processor for portable fuel cell systems
- Author
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Park, GG, Yim, SD, Youn, YG, Lee, WY, Kim, CS, Seo, DJ, and Eguchi, K
- Subjects
fuel processor ,hydrogen production ,portable fuel cells ,methanol combustor ,methanol reformer ,polymer electrolyte membrane fuel cells - Published
- 2005
4. Hydrogen production with integrated microchannel fuel processor for portable fuel cell systems
- Author
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00168775, Park, GG, Yim, SD, Youn, YG, Lee, WY, Kim, CS, Seo, DJ, Eguchi, K, 00168775, Park, GG, Yim, SD, Youn, YG, Lee, WY, Kim, CS, Seo, DJ, and Eguchi, K
- Published
- 2005
5. Hydrogen production with integrated microchannel fuel processor using methanol for portable fuel cell systems
- Author
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00168775, Park, GG, Yim, SD, Yoon, YG, Kirn, CS, Seo, DJ, Eguchi, K, 00168775, Park, GG, Yim, SD, Yoon, YG, Kirn, CS, Seo, DJ, and Eguchi, K
- Published
- 2005
6. Altered brain and physiological stress responses in early psychosis.
- Author
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Feola B, Flook EA, Seo DJ, Fox V, Oler J, Heckers S, Woodward ND, and Blackford JU
- Subjects
- Humans, Male, Female, Young Adult, Adult, Self Report, Saliva metabolism, Adolescent, Stress, Physiological physiology, Psychotic Disorders physiopathology, Heart Rate physiology, Brain physiopathology, Brain diagnostic imaging, Magnetic Resonance Imaging, Stress, Psychological physiopathology, Hydrocortisone metabolism
- Abstract
Stress is proposed to be a crucial factor in the onset and presentation of psychosis. The early stage of psychosis provides a window into how stress interacts with the emergence of psychosis. Yet, how people with early psychosis respond to stress remains unclear. The current study examined how stress responses (brain, physiological, self-report) differ in early psychosis. Forty participants (20 early psychosis [EP], 20 healthy controls [HC]) completed a stress task in the scanner that involved viewing stressful and neutral-relaxing images. Physiological responses (cortisol, heart rate) and self-report of stress were also assessed. Region of Interest analyses were conducted with brain regions previously shown to be activated during the stress task (amygdala, hippocampus, striatum, hypothalamus, prefrontal cortex [dorsolateral, ventrolateral, medial orbital]). Linear mixed models were used to test for effects of group (EP, HC) and emotion (stress, neutral-relaxing). HC had higher hippocampus activation to stress versus neutral-relaxing conditions while EP did not show a difference (group x emotion interaction, p = 0.04). There were also significant main effects of group with EP having higher amygdala activation (p = 0.01), ventrolateral prefrontal cortex activation (vlPFC, p = 0.03), self-report of stress (p = 0.01), and heart rate (p < 0.001). Our study found preliminary evidence that people with early psychosis showed heightened response to stressful and non-threatening situations, across multiple levels of stress responses. Our findings suggest a novel perspective on stress alterations in early psychosis and highlight the importance of considering both stressful and non-stressful situations., Competing Interests: Declaration of competing interest The authors have no conflicts of interest to declare., (Copyright © 2024 Elsevier B.V. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
7. Cross-species transmission and histopathological variation in specific-pathogen-free minipigs infected with different hepatitis E virus strains.
- Author
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Jung S, Yeo D, Seo DJ, Choi IS, and Choi C
- Subjects
- Animals, Swine, Specific Pathogen-Free Organisms, Rabbits, Virus Shedding, Humans, Feces virology, Female, Viremia veterinary, Viremia virology, Hepatitis E veterinary, Hepatitis E virology, Hepatitis E transmission, Hepatitis E virus physiology, Swine Diseases virology, Swine Diseases transmission, Swine Diseases pathology, Swine, Miniature
- Abstract
Hepatitis E virus (HEV) is a major cause of viral hepatitis worldwide. Pigs are the natural host of HEV genotype 3 and the main reservoir of HEV. As the host range of HEV genotype 3 expands, the possibility that HEV from various species can be transmitted to humans via pigs is increasing. We investigated the potential cross-species transmission of HEV by infecting minipigs with swine HEV (swHEV), rabbit HEV (rbHEV), and human HEV (huHEV) and examining their histopathological characteristics and distribution in various organs. Fifteen specific-pathogen-free Yucatan minipigs were infected with swHEV, rbHEV, huHEV, or a mock control. In the present study, we analysed faecal shedding, viremia, and serological parameters over a seven-week period. Our results indicated that swHEV exhibited more robust shedding and viremia than non-swHEVs. Only swHEV affected the serological parameters, suggesting strain-specific differences. Histopathological examination revealed distinct patterns in the liver, pancreas, intestine, and lymphoid tissues after infection with each HEV strain. Notably, all three HEVs induced histopathological changes in the pancreas, supporting the association of HEVs with acute pancreatitis. Our results also identified skeletal muscle as a site of HEV antigen presence, suggesting a potential link to myositis. In conclusion, this study provides valuable insights into the infection dynamics of different HEV strains in minipigs, emphasizing the strain-specific variations in virological, serological, and histological parameters. The observed differences in infection kinetics and tissue tropism will contribute to our understanding of HEV pathogenesis and the potential for cross-species transmission., (© 2024. The Author(s).)
- Published
- 2024
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8. Covalent-Frameworked 2D Crown Ether with Chemical Multifunctionality.
- Author
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Kim J, Kim S, Park J, Kang S, Seo DJ, Park N, Lee S, Kim JJ, Lee WB, Park J, and Lee JC
- Abstract
Here, we present the synthesis and characterization of a novel 2D crystalline framework, named C
2 O , which mainly consists of carbon and oxygen in a 2:1 molar ratio and features crown ether holes in its skeletal structure. The covalent-frameworked 2D crown ether can be synthesized on a gram-scale and exhibits fine chemical stability in various environments, including acid, base, and different organic solvents. The C2 O efficiently activates KI through the strong coordination of K+ with crown ether holes in a rigid framework, which enhances the nucleophilicity of I- and significantly improves its catalytic activity for CO2 fixation with epoxides. The presence of C2 O with KI results in remarkable increases in CO2 conversion from 5.7% to 99.9% and from 2.9% to 74.2% for epichlorohydrin and allyl glycidyl ether, respectively. Moreover, C2 O possesses both electrophilic and nucleophilic sites at the edge of its framework, allowing for the customization of physicochemical properties by a diverse range of chemical modifications. Specifically, incorporating allyl glycidyl ether (AGE) as an electrophile or ethoxyethylamine (EEA) as a nucleophile into C2 O enables the synthesis of C2 O-AGE or C2 O-EEA , respectively. These modified frameworks exhibit improved conversions of 97.2% and 99.9% for CO2 fixation with allyl glycidyl ether, outperforming unmodified C2 O showing a conversion of 74.2%. This newly developed scalable, durable, and customizable covalent framework holds tremendous potential for the design and preparation of outstanding materials with versatile functionalities, rendering them highly attractive for a wide range of applications.- Published
- 2024
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9. Molecular Characteristics of Catalytic Nitrogen Removal from Coal Tar Pitch over γ-Alumina-Supported NiMo and CoMo Catalysts.
- Author
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Choi KH, Seo DJ, Kim YJ, Cho SS, Han YJ, Yang I, Kim CW, Oh K, An JC, and Park JI
- Subjects
- Nitrogen chemistry, Aluminum Oxide, Denitrification, Mass Spectrometry methods, Coal Tar
- Abstract
The removal of nitrogen from coal tar pitch (CTP) through the hydrodenitrogenation (HDN) of CTP and its molecular behavior were evaluated in the presence of NiMo/γ-alumina and CoMo/γ-alumina catalysts. Fourier transform ion cyclotron resonance mass spectrometry with atmospheric pressure photoionization was used to analyze the complicated chemical classes and species of CTP and the treated products at the molecular level. Nitrogen species were qualitatively analyzed before and after hydrotreatment. A single-stage hydrotreatment with an HDN catalyst resulted in a high sulfur removal performance (85.6-94.7%) but a low nitrogen removal performance (26.8-29.2%). Based on relative abundance analyses of nitrogen and binary nitrogen species, C
c Hh -Nn Ss was the most challenging species to remove during HDN treatment. Furthermore, prior hydrodesulfurization was combined with HDN treatment, and the dual hydrotreatments yielded a significantly improved nitrogen removal performance (46.4-48.7%).- Published
- 2023
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10. Effective Removal of Acetaldehyde Using Piperazine/Nitric Acid Co-Impregnated Bead-Type Activated Carbon.
- Author
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Kang YJ, Kim YJ, Yoon SJ, Seo DJ, Cho HR, Oh K, Yoon SH, and Park JI
- Abstract
Acetaldehyde (CH
3 CHO) in the atmosphere is associated with adverse health effects. Among the various options for use in removing CH3 CHO, adsorption is often employed because of its convenient application and economical processes, particularly when using activated carbon. In previous studies, the surface of activated carbon has been modified with amines to remove CH3 CHO from the atmosphere via adsorption. However, these materials are toxic and can have harmful effects on humans when the modified activated carbon is used in air-purifier filters. Therefore, in this study, a customized bead-type activated carbon (BAC) with surface modification options via amination was evaluated for removing CH3 CHO. Various amounts of non-toxic piperazine or piperazine/nitric acid were used in amination. Chemical and physical analyses of the surface-modified BAC samples were performed using Brunauer-Emmett-Teller measurements, elemental analyses, and Fourier transform infrared and X-ray photoelectron spectroscopy. The chemical structures on the surfaces of the modified BACs were analyzed in detail using X-ray absorption spectroscopy. The amine and carboxylic acid groups on the surfaces of the modified BACs are critical in CH3 CHO adsorption. Notably, piperazine amination decreased the pore size and volume of the modified BAC, but piperazine/nitric acid impregnation maintained the pore size and volume of the modified BAC. In terms of CH3 CHO adsorption, piperazine/nitric acid impregnation resulted in a superior performance, with greater chemical adsorption. The linkages between the amine and carboxylic acid groups may function differently in piperazine amination and piperazine/nitric acid treatment.- Published
- 2023
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11. Small RNA sequencing of circulating small extracellular vesicles microRNAs in patients with amyotrophic lateral sclerosis.
- Author
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Kim JA, Park C, Sung JJ, Seo DJ, Choi SJ, and Hong YH
- Subjects
- Humans, Sequence Analysis, RNA, Amyotrophic Lateral Sclerosis pathology, Circulating MicroRNA genetics, MicroRNAs genetics, Extracellular Vesicles genetics, Extracellular Vesicles pathology
- Abstract
Dysregulation of microRNAs (miRNA) in small extracellular vesicles (sEV) such as exosomes have been implicated in the pathogenesis of amyotrophic lateral sclerosis (ALS). Although circulating cell-free miRNA have been extensively investigated in ALS, sEV-derived miRNAs have not been systemically explored yet. Here, we performed small RNA sequencing analysis of serum sEV and identified 5 differentially expressed miRNA in a discovery cohort of 12 patients and 11 age- and sex-matched healthy controls (fold change > 2, p < 0.05). Two of them (up- and down-regulation of miR-23c and miR192-5p, respectively) were confirmed in a separate validation cohort (18 patients and 15 healthy controls) by droplet digital PCR. Bioinformatic analysis revealed that these two miRNAs interact with distinct sets of target genes and involve biological processes relevant to the pathomechanism of ALS. Our results suggest that circulating sEV from ALS patients have distinct miRNA profiles which may be potentially useful as a biomarker of the disease., (© 2023. The Author(s).)
- Published
- 2023
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12. Shape dependence of all-dielectric terahertz metasurface.
- Author
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Seo DJ and Kyoung J
- Abstract
All-dielectric metasurfaces have been attracting attention in the terahertz spectral range for low-loss planar optical elements such as lenses, beam splitters, waveplates, vortex plates, and magnetic mirrors. Various shapes of meta-atoms have been used in many studies; however, no systematic comparative study of each shape has been reported. The optical properties of various shapes of metasurfaces are reported in this work using finite difference time domain simulation. The phase of a pillar-type all-dielectric metasurface is mainly determined by the cross-sectional area, rather than its detailed shape. Consequently, in the square lattice geometry, the square shape meta-atom performs best in terms of full phase control at the lowest pillar height with negligible polarization dependence. Furthermore, we compare the transmission, phase, and polarization dependence of the hexagonal and square lattices. Square-shape metasurface successfully realizes subwavelength focusing metalens and vortex plate.
- Published
- 2022
- Full Text
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13. Prevalence and phylogenetic analysis of human enteric emerging viruses in porcine stool samples in the Republic of Korea.
- Author
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Yeo D, Hossain MI, Jung S, Wang Z, Seo Y, Woo S, Park S, Seo DJ, Rhee MS, and Choi C
- Abstract
Emerging infectious diseases (EID) in humans and animals are proving to be a serious health concern. This study investigated the prevalence of emerging or re-emerging human enteric viruses in porcine stools and swabs. Eleven enteric EID viruses were selected as target viruses for the current study and ranked based on their impact on public health and food safety: enterovirus (EV), hepatitis E virus, norovirus GI and GII, sapovirus (SaV), adenovirus (AdV), astrovirus, rotavirus, hepatitis A virus, aichivirus, and bocavirus. Using real-time RT-PCR or real-time PCR, EID viruses were detected in 129 (86.0%) of 150 samples. The most prevalent virus was EV, which was detected in 68.0% of samples, followed by AdV with a detection rate of 38.0%. In following sequencing and phylogenetic analyses, 33.0% (58/176) of the detected viruses were associated with human enteric EID viruses, including AdV-41, coxsackievirus-A2, echovirus-24, and SaV. Our results show that porcine stools frequently contain human enteric viruses, and that few porcine enteric viruses are genetically related to human enteric viruses. These findings suggest that enteric re-emerging or EID viruses could be zoonoses, and that continuous monitoring and further studies are needed to ensure an integrated "One Health" approach that aims to balance and optimize the health of humans, animals, and ecosystems., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Yeo, Hossain, Jung, Wang, Seo, Woo, Park, Seo, Rhee and Choi.)
- Published
- 2022
- Full Text
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14. Is Late Detection of Hepatocellular Cancer Associated with Better Clinical Outcome?
- Author
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Amjad W and Seo DJ
- Subjects
- Contrast Media, Humans, Tomography, X-Ray Computed, Carcinoma, Hepatocellular, Liver Neoplasms
- Published
- 2022
- Full Text
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15. Nonoperative vs Operative Management of Uncomplicated Acute Appendicitis: A Systematic Review and Meta-analysis.
- Author
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de Almeida Leite RM, Seo DJ, Gomez-Eslava B, Hossain S, Lesegretain A, de Souza AV, Bay CP, Zilberstein B, Marchi E, Machado RB, Barchi LC, and Ricciardi R
- Subjects
- Acute Disease, Adult, Anti-Bacterial Agents therapeutic use, Appendectomy adverse effects, Child, Humans, Treatment Outcome, Appendicitis complications, Appendicitis surgery
- Abstract
Importance: Appendectomy remains the standard of care for uncomplicated acute appendicitis despite several randomized clinical trials pointing to the safety and efficacy of nonoperative management of this disease. A meta-analysis of randomized clinical trials may contribute to the body of evidence and help surgeons select which patients may benefit from surgical and nonsurgical treatment., Objective: To assess the efficacy and safety of nonoperative management vs appendectomy for acute uncomplicated appendicitis., Data Sources: A systematic review was conducted using indexed sources (Embase and PubMed) to search for published randomized clinical trials in English comparing nonoperative management with appendectomy in adult patients presenting with uncomplicated acute appendicitis. To increase sensitivity, no limits were set for outcomes reported, sex, or year of publication. All nonrandomized or quasi-randomized trials were excluded, and validated primers were used., Study Selection: Among 1504 studies imported for screening, 805 were duplicates, and 595 were excluded for irrelevancy. A further 96 were excluded after full-text review, mainly owing to wrong study design or inclusion of pediatric populations. Eight studies met the inclusion criteria and were selected for the meta-analysis., Data Extraction and Synthesis: Meta-extraction was conducted with independent extraction by multiple reviewers using the Covidence platform for systematic reviews and in accordance with PRISMA guidelines. Data were pooled by a random-effects model., Main Outcomes and Measures: Treatment success and major adverse effects at 30 days' follow-up., Results: The main outcome (treatment success proportion at 30 days of follow-up) was not significantly different in the operative and nonoperative management cohorts (risk ratio [RR], 0.85; 95% CI, 0.66-1.11). Likewise, the percentage of major adverse effects was similar in both cohorts (RR, 0.72; 95% CI, 0.29-1.79). However, in the nonoperative management group, length of stay was significantly longer (RR, 1.48; 95% CI, 1.26-1.70), and a median cumulative incidence of 18% of recurrent appendicitis was observed., Conclusions and Relevance: These results point to the general safety and efficacy of nonoperative management of uncomplicated acute appendicitis. However, this strategy may be associated with an increase in duration of hospital stay and a higher rate of recurrent appendicitis. This meta-analysis may help inform decision-making in nonoperative management of uncomplicated acute appendicitis.
- Published
- 2022
- Full Text
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16. Fuel cell performance improvement via the steric effect of a hydrocarbon-based binder for cathode in proton exchange membrane fuel cells.
- Author
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Cha JE, Cho WJ, Hwang J, Seo DJ, Choi YW, and Kim WB
- Abstract
In this study, a sulfonated poly(ether sulfone) having cardo-type fluorenyl groups (FL-SPES) was investigated as a cathodic binder to improve fuel cell performance via increased the oxygen diffusion in the cathode. The maximum power density achieved by using the membrane electrode assembly (MEA) prepared with FL-SPES with a low ion exchange capacity (IEC) of 1.31 meq g
-1 was 520 mW cm-2 , which is more than twice as high as that of BP-SPES (210 mW cm-2 ) having typical biphenyl groups with a similar IEC. At high IEC of 1.55 meq g-1 , the power density obtained by using BP-SPES was improved to 454 mW cm-2 but remained lower than that of FL-SPES. In addition, although the IEC, swelling degree, and specific resistance were similar to each other, the gas permeability of FL-SPES was improved by approximately three times compared to that of BP-SPES. The steric structure of cardo-type FL-SPES increased the free volume between the polymer backbones, leading to an increase in gas transfer. Consequently, oxygen diffusion was promoted at the cathode, resulting in improved fuel cell performance., (© 2022. The Author(s).)- Published
- 2022
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17. Antiviral Bioactive Compounds of Mushrooms and Their Antiviral Mechanisms: A Review.
- Author
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Seo DJ and Choi C
- Subjects
- Animals, Antiviral Agents chemistry, Humans, Plant Extracts chemistry, Virus Diseases drug therapy, Virus Diseases virology, Virus Replication drug effects, Viruses drug effects, Agaricales chemistry, Antiviral Agents pharmacology, Plant Extracts pharmacology
- Abstract
Mushrooms are used in their natural form as a food supplement and food additive. In addition, several bioactive compounds beneficial for human health have been derived from mushrooms. Among them, polysaccharides, carbohydrate-binding protein, peptides, proteins, enzymes, polyphenols, triterpenes, triterpenoids, and several other compounds exert antiviral activity against DNA and RNA viruses. Their antiviral targets were mostly virus entry, viral genome replication, viral proteins, and cellular proteins and influenced immune modulation, which was evaluated through pre-, simultaneous-, co-, and post-treatment in vitro and in vivo studies. In particular, they treated and relieved the viral diseases caused by herpes simplex virus, influenza virus, and human immunodeficiency virus (HIV). Some mushroom compounds that act against HIV, influenza A virus, and hepatitis C virus showed antiviral effects comparable to those of antiviral drugs. Therefore, bioactive compounds from mushrooms could be candidates for treating viral infections.
- Published
- 2021
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18. Effects of Weather and Environmental Factors on the Seasonal Prevalence of Foodborne Viruses in Irrigation Waters in Gyeonggi Province, Korea.
- Author
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Wang Z, Shin H, Jung S, Yeo D, Park H, Shin S, Seo DJ, Park KH, and Choi C
- Abstract
This study aimed to investigate the prevalence of foodborne viruses in reservoirs (an important resource of irrigation water) and its correlation with environmental and weather factors. From May 2017 to November 2018, we visited ten reservoirs and a river in the Anseong region of South Korea and collected a total of 192 samples in accordance with the environment protection agency guidelines. We recorded the weather factors (temperature, humidity, and accumulated precipitation) and investigated the surrounding environment factors (livestock, fishing site, the catchment area of reservoirs, etc.). Our research results show that from the river and reservoirs, the detection rates of human norovirus GII, adenovirus, rotavirus, human norovirus GI, and astrovirus were 27.1, 10.4, 10.4, 4.16, and 3.1%, respectively. Their viral load ranged from -1.48 to 1.55 log
10 genome copies/l. However, hepatitis A virus was not detected in any irrigation water sample. Although no sampling was performed in winter, foodborne viruses and male-specific coliphages were frequently found during spring (40.78%) and autumn (39.47%). Interestingly, the significant correlation between the accumulative precipitation and the number of detected norovirus and adenovirus was confirmed by linear regression analysis. Furthermore, when the accumulative precipitation ranged from 20 to 60 mm, it significantly affected the viral load and prevalence. Among the environmental factors, recreational facilities such as fishing sites and bungalow fishing spots were identified as contamination sources by correlation analysis. Our research results confirmed the correlations between environmental contamination factors in the reservoir and weather factors with the prevalence of foodborne viruses in the reservoir. These facilitates the assessment of potential foodborne virus contamination during crop irrigation. In addition, predictive models including environmental and weather factors should be developed for monitoring and controlling the safety of irrigation waters in reservoirs.- Published
- 2020
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19. Antibacterial activity of various chitosan forms against Xanthomonas axonopodis pv. glycines.
- Author
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Moon C, Seo DJ, Song YS, and Jung WJ
- Subjects
- Cell Proliferation drug effects, Dose-Response Relationship, Drug, Hydrogen-Ion Concentration, Solutions, Xanthomonas axonopodis cytology, Anti-Bacterial Agents chemistry, Anti-Bacterial Agents pharmacology, Chitosan chemistry, Chitosan pharmacology, Xanthomonas axonopodis drug effects
- Abstract
In this study, the antibacterial activities of colloidal chitosan, chitosan solution, and chitooligosaccharide solution were evaluated against Xanthomonas axonopodis pv. glycines grown in peptone sucrose broth (PSB) medium. Treatment with colloidal chitosan (0.01, 0.025, and 0.05%) inhibited X. axonopodis pv. glycines growth only until 36 h. Thin-layer chromatography analysis detected some metabolites, consistently with the cell growth pattern. Two chitooligosaccharides (1-3 kDa and 5-10 kDa) dissolved in distilled water and acetic acid did not exhibit antibacterial activity against X. axonopodis pv. glycines at all tested concentrations (0, 0.001, 0.005, 0.01, 0.015, 0.02, 0.025, and 0.05%). Compared to the control, the chitosan solution decreased X. axonopodis pv. glycines cell growth by 58.7% and 99.0% at concentrations of 0.015% and 0.02%, respectively, after 3 d of incubation. The chitosan solution exhibited the highest antibacterial activity at pH 6.5. However, the antibacterial activity of chitosan decreased in the presence of NaCl and MgCl
2 ., (Copyright © 2019 Elsevier B.V. All rights reserved.)- Published
- 2020
- Full Text
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20. Experimental infection of hepatitis E virus induces pancreatic necroptosis in miniature pigs.
- Author
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Jung S, Seo DJ, Yeo D, Wang Z, Min A, Zhao Z, Song M, Choi IS, Myoung J, and Choi C
- Subjects
- Animals, Disease Models, Animal, Feces virology, Hepatitis E complications, Hepatitis E virology, Hepatitis E virus genetics, Killer Cells, Natural immunology, Liver immunology, Liver pathology, Pancreas immunology, Pancreatitis etiology, Pancreatitis immunology, Pancreatitis virology, RNA, Viral analysis, RNA, Viral blood, Reverse Transcriptase Polymerase Chain Reaction, Swine, Swine Diseases virology, Swine, Miniature, T-Lymphocytes immunology, Hepatitis E immunology, Hepatitis E virus immunology, Necroptosis, Pancreas pathology, Swine Diseases immunology
- Abstract
Infection by hepatitis E virus (HEV) via the oral route causes acute hepatitis. Extra-hepatic manifestations of HEV infection may stem from various causes; however, its distribution in organs such as the liver, as well as the mechanisms underlying HEV-induced cell injury, remain unclear. The objective of this study was to determine the chronological distribution of HEV in various tissues of HEV-challenged miniature pigs and to investigate the mechanisms underlying HEV-induced cell death in the pancreas and liver. Virological and serological analyses were performed on blood and faecal samples. Histopathology of the liver and extra-hepatic tissues was analysed. Cell death pathways and immune cell characterisation in inflammatory lesions were analysed using immunohistochemistry. The liver and pancreas displayed inflammation and cellular injury, and a large amount of HEV was observed in the lesions. The liver was infiltrated by T and natural killer cells. HEV was identified in all organs except the heart, and was associated with immune cells. Although the liver and the pancreas strongly expressed TNF-α and TRAIL, TUNEL assay results were negative. RIP3 and pMLKL were expressed in the pancreas. RIP3, but not pMLKL, was expressed in the liver. Pancreatitis induced in HEV-infected miniature pigs is associated with necroptosis.
- Published
- 2020
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21. Localization and persistence of hepatitis A virus in artificially contaminated oysters.
- Author
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Park H, Jung S, Shin H, Ha SD, Park TJ, Park JP, Seo DJ, and Choi C
- Subjects
- Animals, Food Handling, Gastrointestinal Tract virology, Gills virology, Hepatitis A virus genetics, Shellfish virology, Time Factors, Food Microbiology, Hepatitis A virus physiology, Ostreidae virology
- Abstract
Bivalve molluscan shellfish, such as oysters, clams, and cockles, are well-recognized as vectors that concentrate foodborne pathogens by filter feeding. The objective of this study was to investigate the distribution and persistence of hepatitis A virus (HAV) in experimentally contaminated oysters that were either fed or not fed with algae. Oysters were experimentally contaminated with HAV and maintained in depuration conditions. qRT-PCR, immunohistochemistry (IHC), and in situ hybridization (ISH) were performed on oyster samples collected at 0, 1, 3, 5, and 7 days post-inoculation. When HAV-contaminated oysters were depurated for 7 days, HAV was detected in 91.1-97.8% of the digestive glands and gills. While the high viral load in the digestive glands in oysters did not change significantly regardless of algae-feeding, the viral load of the gills gradually decreased in both groups during the depuration. HAV antigen and RNA were detected in the digestive diverticula and connective tissues by both IHC and ISH. HAV was detected in the stomach, intestine, and gills by only ISH. The distribution of HAV in various oyster tissues may explain the persistence of contamination in oysters during the depuration process., (Copyright © 2019 Elsevier B.V. All rights reserved.)
- Published
- 2019
- Full Text
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22. Foodborne Viruses Detected Sporadically in the Fresh Produce and Its Production Environment in South Korea.
- Author
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Shin H, Park H, Seo DJ, Jung S, Yeo D, Wang Z, Park KH, and Choi C
- Subjects
- Agricultural Irrigation, Demography, Enterovirus isolation & purification, Food Contamination, Hepatitis A virus isolation & purification, Humans, Norovirus isolation & purification, Republic of Korea, Rotavirus isolation & purification, Food Microbiology, Fruit virology, Vegetables virology, Viruses isolation & purification
- Abstract
Contamination of fresh vegetables and berries with human enteric viruses is a major cause of food poisoning. The aim of this study was to investigate the prevalence of norovirus GI, norovirus GII, hepatitis A virus (HAV), adenovirus, astrovirus, rotavirus, and male-specific coliphage systematically in fresh fruit and vegetables and associated agricultural environmental samples, including irrigation water, soil, and worker's gloves. Enteric viruses were detected by international standard methods (ISO/TS 15216), and male-specific coliphages were isolated using US EPA Method 1601. For the study, 773 samples were collected from June 2016 to April 2017, including Chinese cabbage ( n = 244), cucumber ( n = 98), lettuce ( n = 73), strawberry ( n = 120), soil ( n = 191), irrigation water ( n = 14), and gloves ( n = 27). Two cucumber and two irrigation water samples were positive for norovirus GI, and one cucumber and two irrigation water samples were positive for norovirus GII. HAV was detected in one strawberry sample and one glove sample. The other tested foodborne viruses were not detected in any of the samples. Sixteen male-specific coliphages were isolated from Chinese cabbage, cucumber, lettuce, cherry tomato, soil, and irrigation water. The isolation of male-specific coliphage would be more practical to investigate the fecal contamination in produce rather than pathogenic viruses.
- Published
- 2019
- Full Text
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23. Characterization and antifungal activity of chitosanase produced by Pedobacter sp. PR-M6.
- Author
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Song YS, Seo DJ, and Jung WJ
- Subjects
- Antifungal Agents isolation & purification, Bacterial Proteins analysis, Bacterial Proteins chemistry, Chitosan metabolism, Chromatography, Thin Layer, Culture Media chemistry, Electrophoresis, Polyacrylamide Gel, Fungi drug effects, Glycoside Hydrolases isolation & purification, Microbial Sensitivity Tests, Molecular Weight, Pedobacter growth & development, Proteome analysis, Temperature, Time Factors, Antifungal Agents pharmacology, Glycoside Hydrolases pharmacology, Oligosaccharides isolation & purification, Oligosaccharides pharmacology, Pedobacter metabolism
- Abstract
To investigate the temperature requirements of chitosanase activity, as well as the degradation patterns generated by enzyme-induced chitosan oligomer hydrolysis, Pedobacter sp. PR-M6 was inoculated onto 0.5% colloidal chitosan medium agar plates. Cell growth was higher at 30 °C than at 20 °C during the initial 2 days of incubation. The protein content rapidly increased on day 1 at both temperatures and then it slowly increased at 20 °C and slowly decreased at 30 °C during the following 5 days of incubation. In order to characterize the electrophoretic pattern, Pedobacter sp. PR-M6 was cultured in 1% powder chitosan medium at 20 °C and 30 °C for 5 days after incubation and analyzed by SDS-PAGE. Four bands were visible, corresponding to ct1 (25 kDa), ct2 (17 kDa), ct3 (15 kDa), and ct4 (14 kDa), at both 20 °C and 30 °C. The optimal conditions for the activity of chitosanase produced from Pedobacter sp. PR-M6 were 60 °C and 1.81 enzyme units/mg protein. Two major isozyme bands (ct3 and ct4) exhibited their strongest chitosanase activity at 50 °C in SDS-PAGE gel. The reaction products generated from (GlcN)
2 -(GlcN)5 substrates at 60 °C after a 1 h incubation were investigated by thin-layer chromatography. Low-molecular weight chitosan and oligochitosan (LCOC) and soluble chitosan showed antifungal activity against A. brassicicola, B. cinerea, F. solani, and R. solani. LCOC exhibited higher antifungal activity than soluble chitosan. Moreover, LCOC treatments (500 ppm and 1000 ppm) inhibited conidia germination in A. brassicicola., (Copyright © 2019 Elsevier Ltd. All rights reserved.)- Published
- 2019
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24. AA'-Stacked Trilayer Hexagonal Boron Nitride Membrane for Proton Exchange Membrane Fuel Cells.
- Author
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Yoon SI, Seo DJ, Kim G, Kim M, Jung CY, Yoon YG, Joo SH, Kim TY, and Shin HS
- Abstract
Hexagonal boron nitride (h-BN) and graphene have emerged as promising materials for proton exchange membranes because of their high proton conductivity and chemical stability. However, the defects and grain boundaries generated during the growth and transfer of two-dimensional materials limit their practical applicability. Here, we report the fabrication of membrane electrode assemblies using large-area single-oriented AA'-stacked trilayer h-BN (3L-BN), which exhibits very few defects during the growth and transfer, as a proton exchange membrane for use in fuel cell systems. The fuel cell based on AA'-stacked 3L-BN showed a H
2 permeation current density as low as 2.69 mA cm-2 and an open circuit voltage (OCV) as high as 0.958 V; this performance is much superior to those for cells based on Nafion (3.7 mA cm-2 and 0.942 V, respectively) and single-layer h-BN (10.08 mA cm-2 and 0.894 V, respectively). Furthermore, the fuel cell with the AA'-stacked 3L-BN membrane almost maintained its original performance (OCV, maximum power density, and H2 permeation current density) even after 100 h of an accelerated stress test at 30% RH and 90 °C, while the fuel cells with the Nafion and single-layer BN membranes exhibited severely deteriorated performances. The stability of the cell based on the AA'-stacked 3L-BN membrane was better because the membrane prevented gas crossover and suppressed the generation of reactive radicals during cell operation.- Published
- 2018
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25. Identification of Cystoisospora ohioensis in a Diarrheal Dog in Korea.
- Author
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Lee S, Kim J, Cheon DS, Moon EA, Seo DJ, Jung S, Shin H, and Choi C
- Subjects
- Animals, Coccidia genetics, Dogs, Feces parasitology, Female, Phylogeny, Polymerase Chain Reaction methods, RNA, Ribosomal, 18S, Republic of Korea, Coccidia isolation & purification, Coccidiosis parasitology, Coccidiosis veterinary, Diarrhea parasitology, Diarrhea veterinary, Dog Diseases parasitology, Intestinal Diseases, Parasitic parasitology, Intestinal Diseases, Parasitic veterinary, Oocysts isolation & purification
- Abstract
A 3-month-old female Maltese puppy was hospitalized with persistent diarrhea in a local veterinary clinic. Blood chemistry and hematology profile were analyzed and fecal smear was examined. Diarrheal stools were examined in a diagnostic laboratory, using multiplex real-time polymerase chain reaction (PCR) against 23 diarrheal pathogens. Sequence analysis was performed using nested PCR amplicon of 18S ribosomal RNA. Coccidian oocysts were identified in the fecal smear. Although multiplex real-time PCR was positive for Cyclospora cayetanensis, the final diagnosis was Cystoisospora ohioensis infection, confirmed by phylogenetic analysis of 18S rRNA. To our knowledge, this the first case report of C. ohioensis in Korea, using microscopic examination and phylogenetic analysis.
- Published
- 2018
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26. Mitochondrial DNA variations are associated with recurrent pregnancy loss.
- Author
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Azadi A, Seo DJ, Jafari Sasansara H, and Van Haute M
- Subjects
- Adult, Case-Control Studies, Electron Transport Complex I genetics, Female, Genetic Predisposition to Disease, Genome, Mitochondrial, Humans, Mitochondria genetics, Mitochondrial Proteins genetics, Pregnancy, Abortion, Habitual genetics, DNA, Mitochondrial genetics, NADH Dehydrogenase genetics
- Abstract
Cases with three or more consecutive spontaneous abortions before the 20th week of gestation are termed as recurrent pregnancy loss (RPL). Problems in implantation of the foetus and any retarded growth of the foetus in the uterus can be correlated to RPL. Possible causes of RPL would include the genetic variations in the regulatory enzymes of the crucial metabolic pathways, clotting factors, hormones and hormone receptors. This defect of the mitochondrial respiratory chain is recognized as a major cause of human disease. We investigated 73 women with RPL and 100 healthy normal controls. By using the direct sequencing method, the amplified products including the mtDNA complex I genes were analyzed. Overall, seven variations in mitochondrial complex I genes were found (T4216C, A5153G, C10142T, C12062T, A12662G, G14179A and T14263C) using direct sequencing technique. The RPL group had significantly higher proportions of the different variants than those observed of the control group. In conclusion, more research is essentially needed to understand the effect and role of the mitochondrial variations in the progress of RPL, which may vary among individuals and different ethnic groups.
- Published
- 2018
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27. Experimental miniature piglet model for the infection of human norovirus GII.
- Author
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Seo DJ, Jung D, Jung S, Ha SK, Ha SD, Choi IS, Myoung J, and Choi C
- Subjects
- Animal Structures pathology, Animal Structures virology, Animals, Animals, Newborn, Diarrhea pathology, Feces virology, Immunohistochemistry, Lymphocytes virology, Macrophages virology, Norovirus classification, Norovirus genetics, Norovirus isolation & purification, Real-Time Polymerase Chain Reaction, Swine, Swine, Miniature, Time Factors, Virus Shedding, Caliciviridae Infections pathology, Disease Models, Animal, Genotype, Norovirus pathogenicity
- Abstract
Ten Yucatan miniature piglets were challenged with the human norovirus (NoV) GII.12/GII.3 CAU140599 strain and five piglets were used as negative controls. Stool, serum, and organs were collected and processed from two NoV-infected piglets and one negative piglet at 1, 2, 3, 5, and 7 days post-inoculation (dpi). NoV was detected in stool and serum samples by real-time RT-PCR. Mild diarrhea was observed at 1-3 dpi. Fecal shedding and viremia were detected intermittently at 1, 3, and 7 dpi. While interferon-α was significantly elevated at 2-3 dpi, interferon-γ was not changed. Immunohistochemistry demonstrated that the NoV capsid antigen was present in macrophages, lymphocytes, and dendritic cells of the stomach, intestines, lymph nodes, spleen, and tonsils. Intestinal epithelium did not exhibit a positive signal for NoV. In addition, negative-sense viral RNA was confirmed in immune cells by fluorescence in situ hybridization. Therefore, NoV might be associated with macrophages and lymphocytes in gastrointestinal tract and immune organs of experimentally infected miniature piglets., (© 2017 Wiley Periodicals, Inc.)
- Published
- 2018
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28. Expression and degradation patterns of chitinase purified from Xuehuali (Pyrus bretschneiderilia) pollen.
- Author
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Song YS, Lee SH, Cho JA, Moon C, Seo DJ, and Jung WJ
- Subjects
- Amino Acid Sequence genetics, Chitin analogs & derivatives, Chitin chemistry, Chitinases chemistry, Chitinases isolation & purification, Cloning, Molecular, Gene Expression Regulation, Enzymologic, Hydrolysis, Isoenzymes chemistry, Isoenzymes isolation & purification, Pollen chemistry, Pollen genetics, Substrate Specificity, Chitinases genetics, Isoenzymes genetics, Pollen enzymology, Pyrus enzymology
- Abstract
The present study investigated the expression pattern of chitinase in Xuehuali (Pyrus bretschneiderilia) pollen, as well as its subsequent degradation. The chitinase was purified and collected using chitin affinity column chromatography with regenerated chitin. After purification, four additional chitinase isozymes (chiA, chiB, chiC, and chiD) and chitinase (Chi II) were clearly expressed on SDS-PAGE gels that contained 0.01% glycol chitin. The chitinase reaction products were examined using GlcNAc, (GlcNAc)
2 , (GlcNAc)3 , (GlcNAc)4 , (GlcNAc)5 , and (GlcNAc)6 as substrates at 2 and 24h after reaction via TLC and HPLC. The (GlcNAc)4 oligosaccharide was slightly degraded to (GlcNAc)2 after 24h of reaction with Xuehuali pollen chitinase on TLC. Meanwhile, (GlcNAc)5 was degraded to (GlcNAc)2-4 , and 2300ppm (GlcNAc)6 was degraded to 246ppm (GlcNAc)2 , 208ppm (GlcNAc)3 , 572ppm (GlcNAc)4 , and 336ppm (GlcNAc)5 on HPLC. With regard to temperature, the strongest Xuehuali pollen chitinase activity (0.69 unit/mL) was observed at 37°C after 3h of incubation, and with regard to pH, the strongest activity (0.72unit/mL) was observed at pH 3 after 3h of incubation. The main chitin oligomers degraded from (GlcNAc)6 were (GlcNAc)2 and (GlcNAc)4 ., (Copyright © 2017 Elsevier B.V. All rights reserved.)- Published
- 2018
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29. In-stent restenosis-prone coronary plaque composition: A retrospective virtual histology-intravascular ultrasound study.
- Author
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Seo DJ, Kim YK, Seo YH, Song IG, Kim KH, Kwon TG, Park HW, and Bae JH
- Subjects
- Aged, Coronary Angiography, Coronary Restenosis etiology, Coronary Restenosis surgery, Coronary Vessels surgery, Female, Humans, Male, Middle Aged, Plaque, Atherosclerotic complications, Plaque, Atherosclerotic surgery, Retrospective Studies, Coronary Restenosis diagnostic imaging, Coronary Vessels diagnostic imaging, Percutaneous Coronary Intervention, Plaque, Atherosclerotic diagnostic imaging, Stents, Ultrasonography, Interventional methods
- Abstract
Background: The mechanism of in-stent restenosis (ISR) is multifactorial, which includes biological, mechanical and technical factors. This study hypothesized that increased inflammatory reaction, which is known to be an important atherosclerotic process, at a culprit lesion may lead to higher restenosis rates., Methods: The study population consisted of 241 patients who had undergone percutaneous coronary intervention with virtual histology-intravascular ultrasound (VH-IVUS) and a 9-month follow-up coronary angiography. Compared herein is the coronary plaque composition between patients with ISR and those without ISR., Results: Patients with ISR (n = 27) were likely to be older (66.2 ± 9.5 years vs. 58.7 ± 11.7 years, p = 0.002) and have higher levels of high-sensitivity C-reactive protein (hs-CRP, 1.60 ± 3.59 mg/dL vs. 0.31 ± 0.76 mg/dL, p < 0.001) than those without ISR (n = 214). VH-IVUS examination showed that percent necrotic core volume (14.3 ± 8.7% vs. 19.5 ± 9.1%, p = 0.005) was higher in those without ISR than those with ISR. Multivariate analysis revealed that hs-CRP (odds ratio [OR] 3.334, 95% con-fidence interval [CI] 1.158-9.596, p = 0.026) and age (OR 3.557, 95% CI 1.242-10.192, p = 0.018) were associated with ISR., Conclusions: This study suggests that ISR is not associated with baseline coronary plaque composition but is associated with old age and increased expression of the inflammatory marker of hs-CRP. (Cardiol J 2018; 25, 1: 7-13).
- Published
- 2018
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30. Sphingosine Induces Apoptosis and Down-regulation of MYCN in PAX3-FOXO1-positive Alveolar Rhabdomyosarcoma Cells Irrespective of TP53 Mutation.
- Author
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Ahn EH, Lee MB, Seo DJ, Lee J, Kim Y, and Gupta K
- Subjects
- Apoptosis drug effects, Cell Line, Tumor, Down-Regulation drug effects, Forkhead Box Protein O1 metabolism, Humans, Mutation, PAX3 Transcription Factor metabolism, Proto-Oncogene Mas, Rhabdomyosarcoma, Alveolar metabolism, Tumor Suppressor Protein p53 genetics, Antineoplastic Agents pharmacology, N-Myc Proto-Oncogene Protein genetics, Rhabdomyosarcoma, Alveolar genetics, Sphingosine pharmacology
- Abstract
Background/aim: Rhabdomyosarcoma is the most common type of pediatric soft-tissue sarcoma. Among the subsets of this disease, alveolar rhabdomyosarcoma (ARMS) expressing paired box 3 (PAX3) and forkhead box O1 (PAX3-FOXO1) fusion oncoprotein has the worst prognosis. The goal of this study was to investigate the chemotherapeutic effects of sphingosine on PAX3-FOXO1-positive ARMS cells [tumor protein p53 (TP53)-mutated RH30 and TP53 wild-type RH18 cells]., Materials and Methods: The proliferation, cell death, apoptosis, cell cycle, and MYCN proto-oncogene (MYCN) expression of RH30 and RH18 cells were determined., Results: Sphingosine inhibited the growth and caused cell death in a dose-dependent manner in both cell lines. Sphingosine triggered cell death by inducing apoptosis without affecting the cell cycle. MYCN expression was down-regulated within 2 and 4 h of sphingosine treatment in both RH30 and RH18 cells., Conclusion: Sphingosine exerts antiproliferative and pro-apoptotic effects via MYCN down-regulation independently of TP53 mutation status in PAX3-FOXO1-positive ARMS cells., (Copyright© 2018, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)
- Published
- 2018
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31. Rationale of decreasing low-density lipoprotein cholesterol below 70 mg/dL in patients with coronary artery disease: A retrospective virtual histology-intravascular ultrasound study.
- Author
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Seo YH, Seo DJ, Song IG, Kim KH, Kwon TG, and Bae JH
- Subjects
- Biomarkers blood, Cholesterol, LDL drug effects, Coronary Artery Disease diagnosis, Coronary Artery Disease therapy, Dose-Response Relationship, Drug, Female, Follow-Up Studies, Humans, Male, Middle Aged, Percutaneous Coronary Intervention, Plaque, Atherosclerotic diagnosis, Plaque, Atherosclerotic therapy, Prognosis, Retrospective Studies, Cholesterol, LDL blood, Coronary Artery Disease blood, Coronary Vessels diagnostic imaging, Hydroxymethylglutaryl-CoA Reductase Inhibitors administration & dosage, Plaque, Atherosclerotic blood, Ultrasonography, Interventional methods
- Abstract
Background: The associations between statin and coronary plaque compositional changes were re-ported according to the use of high dose or not. An evaluation of the impact of low-density lipoprotein cholesterol (LDL-C) < 70 mg/dL by using real world dosages of statin on coronary plaque composition was undertaken., Methods: The study subjects consisted of 61 patients (mean 59.9 years old, 45 males) who underwent percutaneous coronary intervention, baseline and follow-up (F/U; mean 8.4 months) virtual histology- -intravascular ultrasound (VH-IVUS) examination. Change of plaque composition at peri-stent area, which was selected in order to measure the identical site at F/U study, was compared according to the F/U LDL-C level., Results: Body mass index, prevalence of dyslipidemia, baseline total cholesterol and baseline LDL-C were significantly lower in F/U LDL-C < 70 mg/dL group (14 segments in 10 patients) than F/U LDL-C ≥ 70 mg/dL group (79 segments in 51 patients). F/U high-density lipoprotein cholesterol (HDL-C, OR 1.06, 95% CI 1.00-1.11, p = 0.054) and F/U LDL-C < 70 mg/dL (OR 3.43, 95% CI 0.97-12.17, p = 0.056) showed strong tendency of regression of necrotic core volume (NCV) ≥ 10%. In multivariable logis-tic regression analysis, F/U HDL-C (OR 1.07, 95% CI 1.01-1.14, p = 0.020) and F/U LDL-C < 70 mg/dL (OR 8.02, 95% CI 1.58-40.68, p = 0.012) were the independent factors for regression of NCV ≥ 10%., Conclusions: Follow-up LDL-C level < 70 mg/dL with any types of statins and increase of HDL-C were associated with regression of NCV ≥ 10% in patients with coronary artery disease.
- Published
- 2018
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32. Enzyme activity and expression pattern of intra- and extracellular chitinase and β-1,3-glucanase of Wickerhamomyces anomalus EG2 using glycol chitin and glucan-containing high polymer complex.
- Author
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Hong SH, Song YS, Seo DJ, Kim KY, and Jung WJ
- Subjects
- Chitin pharmacology, Extracellular Space drug effects, Extracellular Space enzymology, Gene Expression Regulation, Fungal drug effects, Glucans chemistry, Intracellular Space drug effects, Intracellular Space enzymology, Pichia cytology, Pichia drug effects, Pichia genetics, Chitin analogs & derivatives, Chitinases genetics, Chitinases metabolism, Glucan 1,3-beta-Glucosidase genetics, Glucan 1,3-beta-Glucosidase metabolism, Glucans pharmacology, Pichia enzymology
- Abstract
We investigated cell growth and activity of intra- and extracellular chitinase, β-1,3-glucanase, and chitin deacetylase with SDS-PAGE by incubating W. anomalus EG2 in PDB and YPD media for 24h in presence of different concentrations (0%, 0.1%, 0.3%, and 0.5%) of colloidal chitin. Maximum cell growth was observed in both PDB and YPD media without colloidal chitin. In the absence of colloidal chitin, maximum extracellular β-1,3-glucanase activity of 32.96 and 47.28 units/mL was reported at 18h in PDB medium and 6h in YPD medium, respectively. In addition, extracellular chitinase was unaffected by various concentrations of carboxymethyl chitin in both PDB and YPD media. In the absence of colloidal chitin, maximum intracellular chitinase activity was indicated to be 9.82 and 9.86 units/mg protein in PDB and YPD media, respectively. Maximum intracellular β-1,3-glucanase activity reported was 17.34 units/mg protein in PDB medium containing 0.5% colloidal chitin and 15.0 units/mg protein in YPD medium containing 0.3% colloidal chitin. Five major isozymes, GN1, GN2, GN3, GN4, and GN5, of intracellular β-1,3-glucanase were detected with glucan-containing high polymer complex as a substrate with or without colloidal chitin., (Copyright © 2017 Elsevier B.V. All rights reserved.)
- Published
- 2017
- Full Text
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33. Antifungal activity and patterns of N-acetyl-chitooligosaccharide degradation via chitinase produced from Serratia marcescens PRNK-1.
- Author
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Moon C, Seo DJ, Song YS, Hong SH, Choi SH, and Jung WJ
- Subjects
- Animals, Chitin chemistry, Chitin metabolism, Chitinases chemistry, Chitinases isolation & purification, Chitosan, Cockroaches microbiology, Enzyme Assays, Enzyme Stability, Fusarium drug effects, Hydrogen-Ion Concentration, Hyphae drug effects, Hyphae growth & development, Methyltransferases, Molecular Weight, Oligosaccharides, Phylogeny, Rhizoctonia drug effects, Serratia marcescens classification, Serratia marcescens genetics, Serratia marcescens isolation & purification, Temperature, Antifungal Agents pharmacology, Chitin analogs & derivatives, Chitinases metabolism, Chitinases pharmacology, Serratia marcescens enzymology
- Abstract
Serratia marcescens PRNK-1, which has strong chitinolytic activity, was isolated from cockroaches (Periplaneta americana L.). The chitinase from S. marcescens PRNK-1 was characterized after incubation in a 0.5% colloidal chitin medium at 30 °C for 3 days. The molecular weights of three bands after staining for chitinase activity were approximately 34, 41, and 48 kDa on an SDS-PAGE gel. S. marcescens PRNK-1 strain strongly inhibited hyphal growth of Rhizoctonia solani and Fusarium oxysporum. Thin-layer chromatography (TLC) and high performance liquid chromatograph (HPLC) analyses were conducted to investigate the degradation patterns of N-acetyl-chitooligosaccharides by PRNK-1 chitinase. The N-acetyl-chitooligosaccharides: N-acetyl-chitin dimer (GlcNAc)
2 , N-acetyl-chitin trimer (GlcNAc)3 , and N-acetyl-chitin tetramer (GlcNAc)4 were degraded to (GlcNAc)1-3 on a TLC plate. In an additional experiment, (GlcNAc)6 was degraded to (GlcNAc)1-4 on a TLC plate. The optimal temperature for chitinase activity of the PRNK-1 was 50 °C, producing 32.8 units/mL. As seen via TLC, the highest degradation of (GlcNAc)4 by PRNK-1 chitinase occurred with 50 °C incubation. The optimal pH for chitinase activity of PRNK-1 was pH 5.5, producing 24.6 units/mL. As seen via TLC, the highest degradation of (GlcNAc)4 by PRNK-1 chitinase occurred at pH 5.0-6.0. These results indicate that chitinase produced from S. marcescens PRNK-1 strain showed strong antifungal activity and potential of production of N-acetyl-chitooligosaccharides., (Copyright © 2017 Elsevier Ltd. All rights reserved.)- Published
- 2017
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34. Isolation and Characterization of Bacillus cereus Bacteriophages from Foods and Soil.
- Author
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Oh H, Seo DJ, Jeon SB, Park H, Jeong S, Chun HS, Oh M, and Choi C
- Subjects
- Bacillus Phages classification, Bacillus Phages genetics, Bacillus Phages physiology, Host Specificity, Siphoviridae classification, Siphoviridae genetics, Siphoviridae physiology, Viral Proteins genetics, Viral Proteins metabolism, Bacillus Phages isolation & purification, Bacillus cereus virology, Food virology, Siphoviridae isolation & purification, Soil Microbiology
- Abstract
The aim of this study was to isolate and characterize Bacillus cereus bacteriophages of various origins. Twenty-seven bacteriophages against B. cereus were isolated from various Korean traditional fermented foods and soils. Plaque size, transmission electron microscopy, virulence profile, and in vitro lytic activity of bacteriophage isolates were examined. Transmission electron microscopy confirmed B. cereus bacteriophages belonging to the family Siphoviridae. Among B. cereus bacteriophages with broad host range, 18 isolates (66.7%) did not harbor any B. cereus virulence factors. Among them, bacteriophage strain CAU150036, CAU150038, CAU150058, CAU150064, CAU150065, and CAU150066 effectively inhibited B. cereus in vitro within 1 h. Therefore, they are considered potential candidates for controlling the contamination of B. cereus in food or other applications.
- Published
- 2017
- Full Text
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35. Antifungal activity and expression patterns of extracellular chitinase and β-1,3-glucanase in Wickerhamomyces anomalus EG2 treated with chitin and glucan.
- Author
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Hong SH, Song YS, Seo DJ, Kim KY, and Jung WJ
- Subjects
- Acetazolamide antagonists & inhibitors, Biological Control Agents, Caffeine antagonists & inhibitors, Candida classification, Candida isolation & purification, Chitinases chemistry, Chitinases drug effects, Fusarium growth & development, Hyphae growth & development, Kinetin antagonists & inhibitors, Molecular Weight, Phylogeny, Plant Pathology, RNA, Ribosomal, 18S genetics, Rhizoctonia growth & development, Antifungal Agents pharmacology, Candida drug effects, Candida enzymology, Cellulases metabolism, Chitin metabolism, Chitinases metabolism, Glucans metabolism
- Abstract
In this study, the expression patterns of extracellular chitinase and β-1,3-glucanase from cultured Wickerhamomyces anomalus EG2 treated with chitin, glucan, and chemical chitinase inhibitors (kinetin, caffeine, and acetazolamide) were investigated using SDS-PAGE. Relationship between enzyme expression and antifungal activity from yeast plays a very important role for biocontrol of phytopathoges. To determine antifungal activity against phytopathogens, W. anomalus EG2 was shown to strongly inhibit hyphal growth of Fusarium oxysporum KACC 40032 and Rhizoctonia solani KACC 40111. Slight chitinase activity was observed 12 h after incubation in both PDB and YPD medium without colloidal chitin. The molecular weight of chitinase was approximately 124 kDa β-1,3-Glucanase isoenzyme (GN1 and GN2) was observed distinctly on SDS-PAGE gels when laminarin was used as a substrate. β-1,3-Glucanase isoenzyme was not observed when using glucan-containing high polymer complex (GHPC) as a substrate. Production of chitinase from W. anomalus EG2 was inhibited slightly by acetazolamide. Abnormal and cluster-shaped cells of W. anomalus EG2 were observed in both PDB and YPD medium treated with colloidal chitin. These results indicated that W. anomalus EG2 could be applied commercially as a biological control agent of phytopathogens and as a bioinhibitor of yeast cell growth., (Copyright © 2017 Elsevier Ltd. All rights reserved.)
- Published
- 2017
- Full Text
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36. Inhibitory mechanism of five natural flavonoids against murine norovirus.
- Author
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Seo DJ and Choi C
- Subjects
- Animals, Catechin analogs & derivatives, Catechin pharmacology, Cell Line, Cytokines genetics, Drug Evaluation, Preclinical methods, Flavonols, Gene Expression Regulation drug effects, Interleukin-6 metabolism, Isoflavones pharmacology, Mice, Nitric Oxide Synthase Type II metabolism, Quercetin pharmacology, Up-Regulation drug effects, Virus Replication drug effects, Antiviral Agents pharmacology, Cytokines metabolism, Flavonoids pharmacology, Norovirus drug effects
- Abstract
Background: Human noroviruses (HuNoV), which are responsible for acute gastroenteritis, are becoming a serious public health concern worldwide. Since no effective antiviral drug or vaccine for HuNoV has been developed yet, some natural extracts and their active components have been investigated for their ability to inhibit noroviruses. However, their exact antiviral mechanisms have not been investigated., Purpose: This study was performed to investigate the expression of interferon (IFN)-α, IFN-λ, tumor necrosis factor-α (TNF-α), Mx, and zinc finger CCCH type antiviral protein 1 (ZAP), 2'-5' oligo (A) synthetase (OAS), and inducible nitric oxide synthase (iNOS) in RAW 264.7 cells pre-treated with fisetin, daidzein, quercetin, epigallocatechin gallate (EGCG), and epicatechin gallate (ECG) that have anti-noroviral activity., Study Design: Based on the antiviral activity of the five flavonoids, recently reported by our group, the expression of antiviral factors such as IFN-α, IFN-λ, TNF-α, IL-1β, IL-6, Mx, ZAP, OAS, and iNOS was investigated in RAW 264.7 cells pre-treated with these flavonoids., Methods: Anti-noroviral effect was determined by performing a plaque assay on cells treated with the flavonoid. RAW 264.7 cells were treated with fisetin, daidzein, quercetin, EGCG, and ECG. Then, mRNA of IFN-α, IFN-λ, TNF-α, IL-1β, IL-6, Mx, ZAP, OAS, and iNOS were measured by real-time RT-PCR. IFN-α, TNF-α, IL-1β, and IL-6 proteins were measured by ELISA., Results: Pre-treatment with fisetin (50μM), fisetin (100μM), EGCG (100μM), quercetin (100μM), daidzein (50μM), and ECG (150μM) significantly reduced MNoV by 50.00±7.14 to 60.67±9.26%. The mRNA levels of IFN-α, IFN-λ, TNF-α, Mx, and ZAP were upregulated in RAW 264.7 cells pre-treated with fisetin, quercetin, and daidzein, but not in those pre-treated with EGCG or ECG. Regarding protein levels, IFN-α was significantly induced in cells pre-treated with fisetin, quercetin, and daidzein, whereas TNF-α was significantly induced only in cells pre-treated with daidzein., Conclusion: Pre-treatment of RAW 264.7 cells with the five flavonoids inhibited MNoV by upregulating the expression of antiviral cytokines (IFN-α, IFN-λ, and TNF-α) and interferon-stimulating genes (Mx and ZAP)., (Copyright © 2017 Elsevier GmbH. All rights reserved.)
- Published
- 2017
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37. Identification, purification, and expression patterns of chitinase from psychrotolerant Pedobacter sp. PR-M6 and antifungal activity in vitro.
- Author
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Song YS, Seo DJ, and Jung WJ
- Subjects
- Agriculture, Biological Control Agents isolation & purification, Botrytis drug effects, Chitin metabolism, Chitinases antagonists & inhibitors, Chromatography, Affinity methods, Cold Temperature, Electrophoresis, Polyacrylamide Gel, Enzyme Assays, Isoenzymes chemistry, Isoenzymes isolation & purification, Mycelium drug effects, Mycelium growth & development, Pedobacter classification, Pedobacter growth & development, Pedobacter isolation & purification, Phylogeny, Rhizoctonia drug effects, Soil Microbiology, Antifungal Agents isolation & purification, Chitinases biosynthesis, Chitinases chemistry, Chitinases isolation & purification, Pedobacter enzymology
- Abstract
In this study, a novel psychrotolerant chitinolytic bacterium Pedobacter sp. PR-M6 that displayed strong chitinolytic activity on 0.5% colloidal chitin was isolated from the soil of a decayed mushroom. Chitinase activity of PR-M6 at 25 °C (C25) after 6 days of incubation with colloidal chitin increased rapidly to a maximum level (31.3 U/mg proteins). Three chitinase isozymes (chiII, chiIII, and chiIV) from the crude enzyme at 25 °C (C25) incubation were expressed on SDS-PAGE gels at 25 °C. After purification by chitin-affinity chromatography, six chitinase isozymes (chiI, chiII, chiIII, chiIV, chiV, and chiVI) from C25-fractions were expressed on SDS-PAGE gels at 25 °C. Major bands of chitinase isozymes (chiI, chiII, and chiIII) from C4-fractions were strongly expressed on SDS-PAGE gels at 25 °C. Pedobacter sp. PR-M6 showed high inhibition rate of 60.9% and 57.5% against Rhizoctonia solani and Botrytis cinerea, respectively. These results indicated that psychrotolerant Pedobacter sp. PR-M6 could be applied widely as a microorganism agent for the biocontrol of agricultural phytopathogens at low temperatures., (Copyright © 2017 Elsevier Ltd. All rights reserved.)
- Published
- 2017
- Full Text
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38. Extension of the T-bridge method for measuring the thermal conductivity of two-dimensional materials.
- Author
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Kim J, Seo DJ, Park H, Kim H, Choi HJ, and Kim W
- Abstract
In this paper, the T-bridge method is extended to measure the thermal properties of two-dimensional nanomaterials. We present an analysis of the measureable positions, width, and thermal resistance of two-dimensional materials. For verification purposes, the thermal conductivity of a SiO
2 nanoribbon was measured. To enhance the thermal contact between the nanoribbon and the heater in the setup, the nanoribbon was dipped into either isopropanol or water in order to promote a sticking force. Also, focused ion beam deposition was used to deposit the nanoribbon onto the contact. The thermal conductivities of all three cases were identical, showing that water dipping could be used to enhance the thermal contact. Due to the simple structure of this method and the analysis provided herein, the T-bridge method can be widely used for measuring the thermal conductivity of two-dimensional materials.- Published
- 2017
- Full Text
- View/download PDF
39. Inhibition of Murine Norovirus and Feline Calicivirus by Edible Herbal Extracts.
- Author
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Seo DJ and Choi C
- Subjects
- Animals, Antiviral Agents isolation & purification, Calicivirus, Feline growth & development, Norovirus growth & development, Plant Extracts isolation & purification, Antiviral Agents pharmacology, Calicivirus, Feline drug effects, Norovirus drug effects, Plant Extracts pharmacology, Plants chemistry
- Abstract
Human noroviruses (HuNoVs) cause foodborne and waterborne viral gastroenteritis worldwide. Because HuNoV culture systems have not been developed thus far, no available medicines or vaccines preventing infection with HuNoVs exist. Some herbal extracts were considered as phytomedicines because of their bioactive components. In this study, the inhibitory effects of 29 edible herbal extracts against the norovirus surrogates murine norovirus (MNV) and feline calicivirus (FCV) were examined. FCV was significantly inhibited to 86.89 ± 2.01 and 48.71 ± 7.38% by 100 μg/mL of Camellia sinensis and Ficus carica, respectively. Similarly, ribavirin at a concentration of 100 μM significantly reduced the titer of FCV by 77.69 ± 10.40%. Pleuropterus multiflorus (20 μg/mL) showed antiviral activity of 53.33 ± 5.77, and 50.00 ± 16.67% inhibition was observed after treatment with 20 μg/mL of Alnus japonica. MNV was inhibited with ribavirin by 59.22 ± 16.28% at a concentration of 100 μM. Interestingly, MNV was significantly inhibited with 150 µg/mL Inonotus obliquus and 50 μg/mL Crataegus pinnatifida by 91.67 ± 5.05 and 57.66 ± 3.36%, respectively. Treatment with 20 µg/mL Coriandrum sativum slightly reduced MNV by 45.24 ± 4.12%. The seven herbal extracts of C. sinensis, F. carica, P. multiflorus, A. japonica, I. obliquus, C. pinnatifida, and C. sativum may have the potential to control noroviruses without cytotoxicity.
- Published
- 2017
- Full Text
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40. Teratomas of the cranial vault: a systematic analysis of clinical outcomes stratified by histopathological subtypes.
- Author
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Lagman C, Bui TT, Voth BL, Chung LK, Seo DJ, Duong C, Libowitz MR, Walker NE, Nagasawa DT, and Yang I
- Subjects
- Female, Humans, Male, Brain Neoplasms mortality, Brain Neoplasms pathology, Brain Neoplasms therapy, Teratoma mortality, Teratoma pathology, Teratoma therapy
- Abstract
Background: Teratomas of the cranial vault are divided into histopathological subtypes and grouped by prognoses: mature (good prognosis), mixed/malignant and immature teratomas (intermediate prognosis). This schema also includes non-teratomatous tumors. The authors of this study sought to elucidate histologically dependent predictors of survival and further clarify the classification system of intracranial teratomas., Methods: We performed a systematic analysis of the published literature to identify studies describing patients with intracranial teratomas diagnosed with magnetic resonance imaging (MRI) and presenting definite information on histologies, therapies, and outcomes at a minimum follow-up of 2 years. Disease-free (DFS) and overall survival (OS) were evaluated., Results: A total of 18 articles comprised of 134 patients were included. On univariate analysis, male sex and gross-total resection (GTR) were associated with high mean DFS (p = 0.0362 and p < 0.0001, respectively). On multivariate analysis, mature teratomas located in the pineal, and those having undergone subtotal resection (STR) demonstrated high mean OS (p = 0.0023 and p = 0.0044, respectively). Mature and mixed/malignant suprasellar teratomas had equally higher mean OS versus immature suprasellar teratomas (p < 0.0001). Mature and immature teratomas treated with adjuvant therapy had significantly higher mean OS compared to those managed with surgery alone (p = 0.0421 and p = 0.0423, respectively). Males with immature teratomas had the highest mean OS (p < 0.0001). Immature teratomas managed with surgery alone had higher mean DFS, but lower mean OS, compared to those treated with adjuvant therapy (p = 0.0176 and p = 0.0423, respectively)., Conclusions: Our data highlight the divergent nature of the different histopathological subtypes of teratomas, and suggest that survival outcomes are multifactorial. Specifically, male sex, pineal, suprasellar, GTR, and STR were dependent predictors of OS, while histopathology was an independent predictor of OS.
- Published
- 2017
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41. Comparative sequence analysis of enteroaggregative Escherichia coli heat-stable enterotoxin 1 identified in Korean and Japanese Escherichia coli strains.
- Author
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Seo DJ, Choi S, Jeon SB, Jeong S, Park H, Lee BH, Kim GB, Yang SJ, Nishikawa Y, and Choi C
- Subjects
- Amino Acid Sequence, Animals, Base Sequence, Cattle, Electrophoresis, Gel, Pulsed-Field, Enterotoxigenic Escherichia coli pathogenicity, Escherichia coli Infections microbiology, Feces microbiology, Hot Temperature, Humans, Japan, Meat microbiology, Plasmids, Polymerase Chain Reaction, Republic of Korea, Sequence Analysis, DNA, Swine microbiology, Swine Diseases microbiology, Virulence genetics, Enterotoxigenic Escherichia coli genetics, Enterotoxigenic Escherichia coli isolation & purification, Enterotoxins genetics, Escherichia coli Proteins genetics
- Abstract
The aim of this study was to compare the sequence of the astA gene found in 8 Korean and 11 Japanese Escherichia coli isolates. Conventional PCR was used to amplify the astA gene from the chromosomal and plasmid DNA preparation samples of each isolate using commercial DNA extraction kits. Cloning of the PCR products, sequence analysis, and pulse field gel electrophoresis (PFGE) were sequentially performed. An identical copy of astA in each isolate were found for 8 Korean and 8 Japanese E. coli strains isolated from bovine, porcine, and healthy human carriers. Among these, 1 Korean and 4 Japanese isolates carried a stop mutation at residue 16. Three Japanese outbreak strains (V199, V638, and 96-127-23) carried multiple clones of astA gene with multiple amino acids changes at residues 11, 16, 20, 23, 30, 33, and 34. Compared with the non-diarrheal isolates, clonal diversity and sequence variations of the astA gene in outbreak isolates may be associated with virulence potential of EAST1., (Copyright © 2016 Elsevier B.V. All rights reserved.)
- Published
- 2017
- Full Text
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42. Fabrication of a vertically-stacked passive-matrix micro-LED array structure for a dual color display.
- Author
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Kang CM, Kong DJ, Shim JP, Kim S, Choi SB, Lee JY, Min JH, Seo DJ, Choi SY, and Lee DS
- Abstract
We report a color tunable display consisting of two passive-matrix micro-LED array chips. The device has combined vertically stacked blue and green passive-matrix LED array chips sandwiched by a transparent bonding material. We demonstrate that vertically stacked blue and green micro-pixels are independently controllable with operation of four color modes. Moreover, the color of each pixel is tunable in the entire wavelength from the blue to green region (450 nm - 540 nm) by applying pulse-width-modulation bias voltage. This study is meaningful in that a dual color micro-LED array with a vertically stacked subpixel structure is realized.
- Published
- 2017
- Full Text
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43. Size-controlled InGaN/GaN nanorod LEDs with an ITO/graphene transparent layer.
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Shim JP, Seong WS, Min JH, Kong DJ, Seo DJ, Kim HJ, and Lee DS
- Abstract
We introduce ITO on graphene as a current-spreading layer for separated InGaN/GaN nanorod LEDs for the purpose of passivation-free and high light-extraction efficiency. Transferred graphene on InGaN/GaN nanorods effectively blocks the diffusion of ITO atoms to nanorods, facilitating the production of transparent ITO/graphene contact on parallel-nanorod LEDs, without filling the air gaps, like a bridge structure. The ITO/graphene layer sufficiently spreads current in a lateral direction, resulting in uniform and reliable light emission observed from the whole area of the top surface. Using KOH treatment, we reduce series resistance and reverse leakage current in nanorod LEDs by recovering the plasma-damaged region. We also control the size of the nanorods by varying the KOH treatment time and observe strain relaxation via blueshift in electroluminescence. As a result, bridge-structured LEDs with 8 min of KOH treatment show 15 times higher light-emitting efficiency than with 2 min of KOH treatment.
- Published
- 2016
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44. A General Approach to Preferential Formation of Active Fe-N x Sites in Fe-N/C Electrocatalysts for Efficient Oxygen Reduction Reaction.
- Author
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Sa YJ, Seo DJ, Woo J, Lim JT, Cheon JY, Yang SY, Lee JM, Kang D, Shin TJ, Shin HS, Jeong HY, Kim CS, Kim MG, Kim TY, and Joo SH
- Abstract
Iron-nitrogen on carbon (Fe-N/C) catalysts have emerged as promising nonprecious metal catalysts (NPMCs) for oxygen reduction reaction (ORR) in energy conversion and storage devices. It has been widely suggested that an active site structure for Fe-N/C catalysts contains Fe-N
x coordination. However, the preparation of high-performance Fe-N/C catalysts mostly involves a high-temperature pyrolysis step, which generates not only catalytically active Fe-Nx sites, but also less active large iron-based particles. Herein, we report a general "silica-protective-layer-assisted" approach that can preferentially generate the catalytically active Fe-Nx sites in Fe-N/C catalysts while suppressing the formation of large Fe-based particles. The catalyst preparation consisted of an adsorption of iron porphyrin precursor on carbon nanotube (CNT), silica layer overcoating, high-temperature pyrolysis, and silica layer etching, which yielded CNTs coated with thin layer of porphyrinic carbon (CNT/PC) catalysts. Temperature-controlled in situ X-ray absorption spectroscopy during the preparation of CNT/PC catalyst revealed the coordination of silica layer to stabilize the Fe-N4 sites. The CNT/PC catalyst contained higher density of active Fe-Nx sites compared to the CNT/PC prepared without silica coating. The CNT/PC showed very high ORR activity and excellent stability in alkaline media. Importantly, an alkaline anion exchange membrane fuel cell (AEMFC) with a CNT/PC-based cathode exhibited record high current and power densities among NPMC-based AEMFCs. In addition, a CNT/PC-based cathode exhibited a high volumetric current density of 320 A cm-3 in acidic proton exchange membrane fuel cell. We further demonstrated the generality of this synthetic strategy to other carbon supports.- Published
- 2016
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45. Central Neurocytoma: A Review of Clinical Management and Histopathologic Features.
- Author
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Lee SJ, Bui TT, Chen CH, Lagman C, Chung LK, Sidhu S, Seo DJ, Yong WH, Siegal TL, Kim M, and Yang I
- Abstract
Central neurocytoma (CN) is a rare, benign brain tumor often located in the lateral ventricles. CN may cause obstructive hydrocephalus and manifest as signs of increased intracranial pressure. The goal of treatment for CN is a gross total resection (GTR), which often yields excellent prognosis with a very high rate of tumor control and survival. Adjuvant radiosurgery and radiotherapy may be considered to improve tumor control when GTR cannot be achieved. Chemotherapy is also not considered a primary treatment, but has been used as a salvage therapy. The radiological features of CN are indistinguishable from those of other brain tumors; therefore, many histological markers, such as synaptophysin, can be very useful for diagnosing CNs. Furthermore, the MIB-1 Labeling Index seems to be correlated with the prognosis of CN. We also discuss oncogenes associated with these elusive tumors. Further studies may improve our ability to accurately diagnose CNs and to design the optimal treatment regimens for patients with CNs., Competing Interests: The authors have no financial conflicts of interest.
- Published
- 2016
- Full Text
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46. Ag nanoparticles-embedded surface plasmonic InGaN-based solar cells via scattering and localized field enhancement.
- Author
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Shim JP, Choi SB, Kong DJ, Seo DJ, Kim HJ, and Lee DS
- Abstract
Ag nanoparticles are embedded in intentionally etched micro-circle p-GaN holes by means of a thermal agglomeration process to enhance the light absorption efficiency in InGaN/GaN multi-quantum-well (MQW) solar cells. The Ag nanoparticles are theoretically and experimentally verified to generate the plasmon light scattering and the localized field enhancement near the MQW absorption layer. The external quantum efficiency enhancement at a target wavelength region is demonstrated by matching the plasmon resonance of Ag nanoparticles, resulting in a J
sc improvement of 9.1%. Furthermore, the Ag-nanoparticle-embedded InGaN solar cell is effectively fabricated considering the carrier extraction that more than 70% of F.F. and 2.2 V of high Voc are simultaneously attained.- Published
- 2016
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- View/download PDF
47. Antifungal activity of chitinase obtained from Paenibacillus ehimensis MA2012 against conidial of Collectotrichum gloeosporioides in vitro.
- Author
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Seo DJ, Lee YS, Kim KY, and Jung WJ
- Subjects
- Antifungal Agents isolation & purification, Chitinases isolation & purification, Chromatography, Gel, Chromatography, Ion Exchange, Culture Media chemistry, Electrophoresis, Gel, Two-Dimensional, Electrophoresis, Polyacrylamide Gel, Gene Expression Profiling, Isoenzymes isolation & purification, Isoenzymes metabolism, Paenibacillus growth & development, Temperature, Antifungal Agents metabolism, Chitinases metabolism, Colletotrichum drug effects, Paenibacillus enzymology, Spores, Fungal drug effects
- Abstract
To investigate the expression patterns of chitinase on SDS-PAGE gel, Paenibacillus ehimensis MA2012 was incubated in gelatin-chitin medium (GCM) at 30 °C for 7 days. Six major bands (Ch3, Ch4, Ch5, Ch6, Ch7, and Ch8) of chitinase isozymes in GC medium appeared on SDS-PAGE gel during the incubation period. Chitinase activity staining of P. ehimensis MA2012 was detected on 2-DE with different pI values (4-11). After DEAE-Sephadex chromatography, eight bands (Ch1 to Ch8) of chitinase isozymes were stained strongly with Calcofluor white M2R at fraction 45. After Sephadex G-75 gel filtration, six bands (Ch3 to Ch8) of chitinase isozymes were stained with Calcofluor white M2R at fractions of 11-12. The specific activity of the purified chitinase was 3.8 units mg(-1) protein with a purification factor of 0.27. Inhibition rate of the conidial germination of Colletotrichum gloeosporioides was 87% in partial purified chitinase treatment compared with control., (Copyright © 2016 Elsevier Ltd. All rights reserved.)
- Published
- 2016
- Full Text
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48. Simultaneous Detection and Prevalence of Allergens in Anisakis Species Isolated from Marine Fishes.
- Author
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Lee WJ, Seo DJ, Oh H, Jeon SB, Jung D, and Choi C
- Subjects
- Allergens, Animals, Fish Diseases, Larva, Prevalence, Republic of Korea, Anisakis, Fishes parasitology
- Abstract
This study was conducted to develop a multiplex reverse transcription (RT) PCR for the detection of Anisakis allergens and to investigate the relationship between allergen profiles and anisakid larvae isolated from Scomber japonicus, Trichiurus lepturus, and Conger myriaster in Korea. The species of Anisakis was determined using Anisakis pegreffii-specific PCR and restriction fragment length polymorphism analysis. The prevalence and profiles of five Ani s allergens were examined by multiplex RTPCR. A. pegreffii and Anisakis typica accounted for 97.1 and 2.9%, respectively, of the 140 larvae examined. In A. pegreffii, allergen prevalence was 41.2% for Ani s 1, 72.1% for Ani s 2, 69.9% for Ani s 3, 86.7% for Ani s 4, and 93.4% for Ani s 5. Most A. pegreffii larvae had multiple allergen profiles, and 80.7% of A. pegreffii carried both Ani s 4 and Ani s 5, which are heat-resistant allergens. Fifty-two to 65% of A. pegreffii isolated from S. japonicus and C. myriaster carried all five Ani s allergens.
- Published
- 2016
- Full Text
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49. Analysis of Plaque Composition in Coronary Chronic Total Occlusion Lesion Using Virtual Histology-Intravascular Ultrasound.
- Author
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Park YH, Kim YK, Seo DJ, Seo YH, Lee CS, Song IG, Yang DJ, Kim KH, Park HW, Kim WH, and Bae JH
- Abstract
Background and Objectives: Success rates of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) have recently been reported to range from 80% to 90%. A better understanding of the pathologic characteristics of the CTO lesion may helpful to improving CTO PCI success rates. We evaluated the CTO lesion in patients with stable angina (SA) by virtual histology-intravascular ultrasound (VH-IVUS)., Subjects and Methods: The study population consisted of 149 consecutive patients with SA underwent VH-IVUS examination. We analyzed demographic and VH-IVUS findings in 22 CTO patients (17 males; mean, 62.3 years old) compared with 127 non-CTO patients (82 males; mean, 61.3 years old)., Results: A significantly lower ejection fraction (57.6±13.0% vs. 65.4±8.8%, p=0.007) was detected in the CTO group compared with the non-CTO group. Reference vessel lumen area of the proximal and distal segment was significantly less in CTO group than in non-CTO group. The lesion length of the CTO group was significantly longer than those of the non-CTO group (24.4±9.6 mm vs. 17.2±7.4 mm, p<0.001). Total atheroma volume (224±159 mm(3) vs. 143±86 mm(3), p=0.006) and percent atheroma volume (63.2±9.6% vs. 55.8±8.5%, p=0.011) of the CTO group were also significantly greater than those of non-CTO group. However, the lesion length adjusted plaque composition of the CTO group was not significantly different compared with that of the non-CTO group., Conclusion: CTO lesions had a longer lesion length and greater plaque burden than the non-CTO lesion in patients with SA. However, lesion length adjusted plaque composition showed similar between the two groups. These results support that plaque characteristics of CTO lesions are similar to non-CTO lesions in patients with SA.
- Published
- 2016
- Full Text
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50. Inhibiting the Growth of Escherichia coli O157:H7 in Beef, Pork, and Chicken Meat using a Bacteriophage.
- Author
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Seo J, Seo DJ, Oh H, Jeon SB, Oh MH, and Choi C
- Abstract
This study aimed to inhibit Escherichia coli (E. coli) O157:H7 artificially contaminated in fresh meat using bacteriophage. Among 14 bacteriophages, the highly lytic bacteriophage BPECO19 strain was selected to inhibit E. coli O157:H7 in artificially contaminated meat samples. Bacteriophage BPECO19 significantly reduced E. coli O157:H7 bacterial load in vitro in a multiplicity of infection (MOI)-dependent manner. E. coli O157:H7 was completely inhibited only in 10 min in vitro by the treatment of 10,000 MOI BPECO19. The treatment of BPECO19 at 100,000 MOI completely reduced 5 Log CFU/cm(2) E. coli O157:H7 bacterial load in beef and pork at 4 and 8h, respectively. In chicken meat, a 4.65 log reduction of E. coli O157:H7 was observed at 4 h by 100,000 MOI. The treatment of single bacteriophage BPECO19 was an effective method to control E. coli O157:H7 in meat samples.
- Published
- 2016
- Full Text
- View/download PDF
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