• Journal of Microbiology and Biotechnology
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• v.32 no.4
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• pp.522-530
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• 2022

In this study we aimed to develop novel ZnO-NP/chitosan/β-glycerophosphate (ZnO-NP/CS/β-GP) antibacterial hydrogels for biomedical applications. According to the mass fraction ratio of ZnO-NPs to chitosan, mixtures of 1, 3, and 5% ZnO-NPs/CS/β-GP were prepared. Using the test-tube inversion method, scanning electron microscopy and Fourier-transform infrared spectroscopy, the influence of ZnO-NPs on gelation time, chemical composition, and cross-sectional microstructures were evaluated. Adding ZnO-NPs significantly improved the hydrogel's antibacterial activity as determined by bacteriostatic zone and colony counting. The hydrogel's bacteriostatic mechanism was investigated using live/dead fluorescent staining and scanning electron microscopy. In addition, crystal violet staining and MTT assay demonstrated that ZnO-NPs/CS/β-GP exhibited good antibacterial activity in inhibiting the formation of biofilms and eradicating existing biofilms. CCK-8 and live/dead cell staining methods revealed that the cell viability of gingival fibroblasts (L929) cocultured with hydrogel in each group was above 90% after 24, 48, and 72 h. These results suggest that ZnO-NPs improve the temperature sensitivity and bacteriostatic performance of chitosan/β-glycerophosphate (CS/β-GP), which could be injected into the periodontal pocket in solution form and quickly transformed into hydrogel adhesion on the gingiva, allowing for a straightforward and convenient procedure. In conclusion, ZnO-NP/CS/β-GP thermosensitive hydrogels could be expected to be utilized as adjuvant drugs for clinical prevention and treatment of peri-implant inflammation.

• Journal of Plant Biotechnology
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• v.49 no.4
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• pp.271-291
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• 2022

Pectin methylesterase (PME) plays an important role in vegetative and reproductive development and biotic/abiotic stress responses by regulating the degree of methyl-esterification of pectic polysaccharides in the plant cell wall. PMEs are encoded by a large multigene family in higher land plant genomes. In general, the expression of plant PME genes shows tissue- or cell-specific patterns and is induced by endogenous and exogenous stimuli. In this study, we identified PME multigene family members (CsPMEs) from the sweet orange genome and report detailed molecular characterization and expression profiling in different citrus tissues and two fruit developmental stages. We also discussed the possible functional roles of some CsPME genes by comparing them with the known functions of PMEs from other plant species. We identified 48 CsPME genes from the citrus genome. A phylogenetic tree analysis revealed that the identified CsPMEs were divided into two groups/types. Some CsPMEs showed very close phylogenetic relationships with the PMEs whose functions were formerly addressed in Arabidopsis, tomato, and maize. Expression profiling showed that some CsPME genes are highly or specifically expressed in the leaf, root, flower, or fruit. Based on the phylogenetic relationships and gene expression profiling results, we suggest that some CsPMEs could play functional roles in pollen development, pollen tube growth, cross incompatibility, root development, embryo/seed development, stomata movement, and biotic/abiotic stress responses. Our results shed light on the biological roles of individual CsPME isoforms and contribute to the search for genetic variations in citrus genetic resources.

• Journal of Forest and Environmental Science
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• v.26 no.2
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• pp.83-94
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• 2010

Chinese fir (Latin name: Cunninghaimia lanceolata) is one of the major commercial coniferous trees. Most of Chinese fir forests are managed in successive rotation sites, which lead productivity to decline. Autotoxicity is the important reason for soil degradation of Chinese fir plantation, especially, phenolic acids are considered as the major allelopathic toxins which induce autotoxicity in Chinese fir rotation stands. We performed here proteomic approach to investigate the response of proteins in Chinese fir leaves to salicylic acid. The tube plantlets of Chinese fir clone were treated with 120 mg/L salicylic acid for 1, 3 and 5th day. 2-DE, coupled with MALDI-TOF-TOF/MS, was used to separate and identify the responsive proteins. We found 12, 7, and 12 candidate protein spots that were up- or down-regulated by at least 2.5 fold after 1, 3, and 5th day of the stress, respectively. Of these protein spots, 16 spots were identified successfully. According to the putative physiological functions, these proteins were categorized into five classes (1) the proteins involved in protein stability and folding, including 26S proteome, Grp78, Hsp70, Hsp90 and PPIase; (2) the protein involved in photosynthesis and respiration, including OEC 33 kDa subunit, GAPDH; (3) the protein related to cell endurance to acid, F-ATPase; (4) the protein related to cytoskeleton, tubulin; (5) the protein related to protein translation: prolyl-tRNA synthetase. These results give new insights into autotoxic substance stress response in Chinese fir leaves and provide preliminary footprints for further studies on the molecular signal mechanisms induced by the stress.

• Nuclear Engineering and Technology
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• v.55 no.7
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• pp.2621-2627
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• 2023

In Experimental Advanced Superconducting Tokamak (EAST) experiments, to achieve long pulse and high-power ICRH system operation, a new kind of ICRH antenna has been designed. One of the most critical factors in limiting the operation of long pulse and high power is the intense heat load in the front face of the ICRH antenna, especially the Faraday Screen (FS). Therefore, the cooling channels of FS need to be designed. According to thermal-hydraulic analysis, the FS tubes are divided into several groups to achieve more excellent water cooling capability. The number of series and parallel tubes in one group is chosen as six. This antenna went into service in the spring of 2021, and it is delightful that the temperature distribution of the FS tube is below 400 ℃ in 14.5 s and 1.8 MW ICRH system operation. However, the active water-cooling design was not carried out on the upper and lower plates of FS, which led to severe ablations on that region under long pulse and high power operation, and the temperature is up to 800. Therefore, the upper and lower side plates of the FS were designed with water cooling based on thermal-hydraulic analysis. During the 2022 winter experiments, the temperature of ICRH antenna FS was lower than 400 in the pulse of 200s and the power of 1 MW operation.

• The Korean Journal of Nuclear Medicine Technology
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• v.27 no.2
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• pp.133-136
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• 2023

Purpose: Prolactin in the blood is separated into three types, and over 90% of prolactin presents as a double monomer (23 KDa). Rarely, it can exist in the size of big prolactin (150 KDa), which is called macroprolactin and is known as an autoantibody complex. When macroprolactin accounts for more than 60% of prolactin in the blood, it is called macroprolactinemia. The presence of such macroprolactin was first reported in a patient with hyperprolactinemia but without typical symptoms. Macroprolactinemia is emerging as an important cause of idiopathic hyperprolactinemia. The polyethylene glycol (PEG) precipitation method using the property of precipitating large-molecular-weight proteins is simple and recently has been widely used as a screening test. The results are in good agreement with the results of gel chromatography. The purpose of this study was to confirm the measurement method and reference value verification of monomeric prolactin in blood prolactin using the PEG precipitation method. Materials and Methods: For 40 examinees who visited the Gangnam Center of Seoul National University Hospital in 2021, the prolactin level was verified using radioimmunoassay (RIA). For macroprolactinemia PEG precipitation method, 25% PEG (molecular weight 6000kDa) solution and serum were mixed in equal amounts in a test tube, then left at room temperature for 20 minutes and centrifuged at 4℃ for 30 minutes (1500g). The prolactin level was measured in the supernatant. Results : After confirming that more than 90% of the 40 tested samples within the reference range <25 ng/mL, the same value as the reference value for prolactin was applied. Since the concentration of monomeric prolactin in serum from which macroprolactin has been removed from blood is diluted 1:1 with PEG, our laboratory is currently reporting the result by multiplying the result by a dilution factor of 2. Conclusion: Radioimmunoassay using PEG precipitation method using the property of precipitating large molecular weight proteins is simple and effective for quantitative measurement of monomeric prolactin in blood prolactin.

• International Journal of Oncology
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• v.54 no.2
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• pp.753-763
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• 2019

The mutation of isocitrate dehydrogenase (IDH)1 (R132H) and IDH2 (R172K) and the induction of hypoxia in various solid tumors results in alterations in metabolic profiles, including the production of the d- or l-forms of 2-hydroxyglutarate (2HG) from α-ketoglutarate in aerobic metabolism in the tricarboxylic acid (TCA) cycle. However, it is unclear whether the oncometabolite d-2HG increases angiogenesis in endothelial cells. Therefore, in this study, we analyzed the levels of various metabolites, including d-2HG, under hypoxic conditions and in IDH2R172K mutant breast cancer cells by mass spectrometry. We then further evaluated the effects of this metabolite on angiogenesis in breast cancer cells. The results revealed that treatment with d-2HG increased the levels of secreted vascular endothelial growth factor (VEGF) in cancer cells and enhanced endothelial cell proliferation in a concentration-dependent manner. Wound healing and cell migration (examined by Transwell assay) were significantly increased by d-2HG to a level similar to that induced by VEGF. Tube formation was significantly stimulated by d-2HG, and chick chorioallantoic membrane angiogenesis was also enhanced by d-2HG. d-2HG activated VEGF receptor (VEGFR)2 and VEGFR2 downstream signaling, extracellular signal-regulated kinase 1/2, focal adhesion kinase, AKT and matrix metalloproteinase (MMP)2. Taken together, the findings of this study suggested that d-2HG induced angiogenic activity via VEGFR2 signaling and increased MMP2 activity.

• Economic and Environmental Geology
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• v.45 no.3
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• pp.277-294
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• 2012

The characteristics of temporal spacial radon variation in soil according to parent rock type and affecting factors were studied in Busan, Korea. The concentration of $^{222}Rn$ in soils and their parent elements ($^{226}Ra$,$^{228}Ra$, U and Th) in rocks and soils were measured at 24 sites in Busan area. The distribution and transportation behavior of these parent elements were analyzed and their correlations to radon concentration in soil were determined. Topographic effects were also evaluated. Two in-situ radon measurement (soil probe and buried tube) methods were applied to measure radon concentration in soil and their accuracies were evaluated. The spatial variation of radon in soil generally reflected U concentration in the parent rock. Average radon concentrations were higher in plutonic rocks than in volcanic rocks and were decreased in the order of felsic>intermediate>mafic rock. However, the radon concentrations were significantly varied in soils developed from same parent rocks due to the disequilibrium of U and $^{226}Ra$ between rock and soil. As results, the correlation of these element concentrations between rocks and soils was very low and radon concentrations in soils had highly co-related to the concentrations of these elements in soils. Th and $^{228}Ra$ show complex enrichment characteristics, differing significantly with U, in soils developed from same parent rock because the geochemical behavior of these elements during weathering and soil developing process was different with U. The radon concentrations in the same depth of soil in slope area were also different according to positions. The radon concentrations in soils developed from same parent rocks (19 sites at Pusan National University) varied 6.8~29.8Bq/L range because of small scale topographic variation. The opposite seasonal variation pattern of radon were observed according to soil properties. It was determined that buried tube method is more accurate method than soil probe method and was very advantageous application for the analysis for the characteristics of temporal spacial radon variation in soil.

• Economic and Environmental Geology
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• v.49 no.6
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• pp.459-467
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• 2016

Due to the limited areal space for installation, borehole heat exchangers (BHEs) at depths deeper than 300 m are considered for geothermal heating and cooling in the urban area. The deep vertical closed-loop BHEs are unconventional due to the depth and the range of the typical installation depth is between 100 and 200 m in Korea. The BHE in the study consists of 50A (outer diameter 50 mm, SDR 11) PE U-tube pipe in a 150 mm diameter borehole with the depth of 300 m. In order to compensate the buoyancy caused by the low density of PE pipe ($0.94{\sim}0.96g/cm^3$) in the borehole filled with ground water, 10 weight band sets (4.6 kg/set) were attached to the bottom of U-tube. A thermal response test (TRT) and fundamental basic surveys on the thermophysical characteristics of the ground were conducted. Ground temperature measures around $15^{\circ}C$ from the surface to 100 m, and the geothermal gradient represents $1.9^{\circ}C/100m$ below 100 m. The TRT was conducted for 48 hours with 17.5 kW heat injection, 28.65 l/min at a circulation fluid flow rate indicates an average temperature difference $8.9^{\circ}C$ between inlet and outlet circulation fluid. The estimated thermophysical parameters are 3.0 W/mk of ground thermal conductivity and 0.104 mk/W of borehole thermal resistance. In the stepwise evaluation of TRT, the ground thermal conductivity was calculated at the standard deviation of 0.16 after the initial 13 hours. The sensitivity analysis on the borehole thermal resistance was also conducted with respect to the PE pipe diameter and the thermal conductivity of backfill material. The borehole thermal resistivity slightly decreased with the increase of the two parameters.

• Journal of Chest Surgery
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• v.39 no.8 s.265
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• pp.579-587
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• 2006

Background: Preoperative risk analysis for Fontan candidates is still less than optimal in that patients with apparently low risks may have poor surgical outcome; prolonged pleural drainage, protein losing enteropathy, pulmonary thromboembolism and death. We hypothesized that low pulmonary vascular compliance (PVC) is a risk factor for prolonged pleural effusion drainage after the Fontan operation. Material and Method: A retrospective review of 96 consecutive patients who underwent the Extracardiac Fontan procedures (median age: 3.9 years) was performed. Fontan risk score (FRS) was calculated from 12 categorized preoperative anatomic and physiologic variables. PVC $(mm^2/m^2{\cdot}mmHg)$ was defined as pulmonary artery index $(mm^2/m^2)$ divided by total pulmonary resistance $(W.U{\cdot}/m^2)$ and pulmonary blood flow $(L/min/m^2)$ based on the electrical circuit analogue of the pulmonary circulation. Chest tube indwelling time was log-transformed (log indwelling time, LIT) to fit normal distribution, and the relationship between preoperative predictors and LIT was analyzed by multiple linear regression. Result: Preoperative PVC, chest tube indwelling time and LIT ranged from 6 to 94.8 $mm^2/mmHg/m^2$ (median: 24.8), 3 to 268 days (median: 20 days), and 1.1 to 5.6 (mean: 2.9, standard deviation: 0.8), respectively. FRS, PVC, cardiopulmonary bypass time (CPB) and central venous pressure at postoperative 12 hours were correlated with LIT by univariable analyses. By multiple linear regression, PVC (p=0.0018) and CPB (p=0.0024) independently predicted LIT, explaining 21.7% of the variation. The regression equation was LIT=2.74-0.0158 PVC+0.00658 CPB. Conclusion: Low pulmonary vascular compliance is an important risk factor for prolonged pleural effusion drainage after the extracardiac Fontan procedure.

• Journal of Chest Surgery
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• v.42 no.1
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• pp.34-40
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• 2009

Background: The principal surgical technique for treating an abdominal aortic aneurysm since the 1960s has been the transperitoneal approach, yet there have been some recent studies that have reported improved surgical results with using the retroperitoneal approach. However, there are only limited clinical Korean studies that have, compared between the transperitoneal and retroperitoneal approaches. Material and Method: This study included 36 patients who had been diagnosed as having an aneurysm of the abdominal aorta and they were surgically treated between January 2001 and July 2007. The patients were subdivided into the retroperitoneal approach group (n=17) and the transperitoneal approach group (n=19), and they were compared in terms of the preoperative risk factors, the postoperative complications and the operative mortality. The risk factors of operative mortality risk and long-term survival for the 36 patients were assessed by the Kaplan-Meier method. Result: There were no significant differences between the groups in terms of gender, age, the underlying disease, a history of smoking, rupture of aneurysm, the preoperative symptoms, the operation time and the incidence of postoperative complications. However, the duration of postoperative fasting, the number of days of having an indwelling nasogastric tube and the length of the stay in the intensive care unit were significantly short for the retroperitoneal approach group (p<0.05). There was a 16.7% rate of operative mortality (6/36) and five of the deaths were attributed to preoperative ruptured aneurysm. On univariate analysis, a higher preoperative serum creatinine level (SCr ${\geq}$1.8 mg/dL, p=0.016) and ruptured aneurysm (p<0.001) were the significant risk factors of operative mortality. As assessed by the Kaplan-Meier method, the long-term survival was comparable between the groups and the five-year survival rate of all the patients was 57.5%. Conclusion: In the present study, a retroperitoneal approach has several advantages such as a shorter intensive care unit stay, a shorter duration of postoperative fasting and a shorter duration of an indwelling nasogastric tube. Therefore, unless there is any contraindication for a retroperitoneal approach, it could be considered as a primary surgical access for repairing an abdominal aortic aneurysm.