• Journal of the Korean Society for Aviation and Aeronautics
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• v.31 no.3
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• pp.50-58
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• 2023

Sudden wind changes at low altitudes pose a significant threat to aircraft operations. In particular, airports located in regions with complex terrain are susceptible to frequent abrupt wind variations, affecting aircraft takeoff and landing. To mitigate these risks, Low Level Wind shear Alert System (LLWAS) have been implemented at airports. This study focuses on understanding the characteristics of wind shear and developing a prediction model for Jeju International Airport, which experiences frequent wind shear due to the influence of Halla Mountain and its surrounding terrain. Using two years of LLWAS data, the study examines the occurrence patterns of wind shear at Jeju International Airport. Additionally, high-resolution numerical model is utilized to produce forecasted information on wind shear. Furthermore, a comparison is made between the predicted wind shear and LLWAS observation data to assess the prediction performance. The results demonstrate that the prediction model shows high accuracy in predicting wind shear caused by southerly winds.

• Journal of Veterinary Clinics
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• v.40 no.6
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• pp.452-456
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• 2023

This report presents two rare cases of gallbladder rupture in dogs with small gallbladders that did not result in bile leakage and their subsequent surgical treatment. The report includes a 5-year-old spayed female Chihuahua weighing 3.5 kg and a 9-year-old castrated male Poodle weighing 5.3 kg. Both dogs had elevated liver enzyme levels on blood chemistry. However, only the second dog (2) (Poodle) presented with hyperbilirubinemia and jaundice, whereas the first dog (Chihuahua (1)) did not display any specific clinical signs. Diagnostic imaging revealed a small gallbladder in both dogs, and the dogs were diagnosed with cholecystolithiasis (1) and extrahepatic biliary tract obstruction (2). No bile leakage-related abdominal effusion was observed. Gallbladder rupture and adhesion to the adjacent tissues were confirmed during cholecystectomy.

• Clinical Endoscopy
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• v.56 no.1
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• pp.114-118
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• 2023

Gastric wall abscess, a localized form of phlegmonous gastritis, is a rare complication of endoscopic resection. We report the first case of gastric wall abscess developing after endoscopic submucosal dissection in Korea. A 72-year-old woman visited our clinic to receive treatment for gastric adenoma. The patient successfully underwent endoscopic submucosal dissection with no complications. The final diagnosis was well-differentiated tubular adenocarcinoma. We performed follow-up endoscopy 10 weeks later and found a large subepithelial lesion on the posterior wall of the gastric antrum. Abdominal computed tomography revealed hypodense wall thickening and a 5 cm heterogenous multilobular mass in the submucosal layer of the gastric antrum. Submucosal invasion with mucin-producing adenocarcinomas could therefore not be excluded. The patient agreed to undergo additional gastrectomy due to the possibility of a highly malignant lesion. The final diagnosis was acute suppurative inflammation with the formation of multiple abscesses in the mural layers and omentum. The patient was discharged with no complications.

• Molecules and Cells
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• v.46 no.12
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• pp.757-763
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• 2023

In this study, we examine whether a change in the protein levels for FOP in Ankyrin repeat and SAM domain-containing protein 1A (ANKS1A)-deficient ependymal cells affects the intraflagellar transport (IFT) protein transport system in the multicilia. Three distinct abnormalities are observed in the multicilia of ANKS1A-deficient ependymal cells. First, there were a greater number of IFT88-positive trains along the cilia from ANKS1A deficiency. The results are similar to each isolated cilium as well. Second, each isolated cilium contains a significant increase in the number of extracellular vesicles (ECVs) due to the lack of ANKS1A. Third, Van Gogh-like 2 (Vangl2), a ciliary membrane protein, is abundantly detected along the cilia and in the ECVs attached to them for ANKS1A-deficient cells. We also use primary ependymal culture systems to obtain the ECVs released from the multicilia. Consequently, we find that ECVs from ANKS1A-deficient cells contain more IFT machinery and Vangl2. These results indicate that ANKS1A deficiency increases the entry of the protein transport machinery into the multicilia and as a result of these abnormal protein transports, excessive ECVs form along the cilia. We conclude that ependymal cells make use of the ECV-based disposal system in order to eliminate excessively transported proteins from basal bodies.

• Journal of Ceramic Processing Research
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• v.22 no.2
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• pp.214-220
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• 2021

Heterolayered potassium tantalate niobate(KTN(70/30)/KTN(30/70)) thin films on Pt/Ti/SiO2/Si substrates prepared by the sol-gel process and spin coating method. When sintered at 700 ℃ or higher, the X-ray diffraction intensities of the perovskite phase were greatly increased, and it was observed as the main phase of the KTN heterolayered thin film. As the sintering temperature increased from 650 ℃ to 800 ℃, the average grain size increased from 146nm to 380 nm, and the average thickness of the KTN films coated six times was about 394-441 nm. Dielectric constant and dielectric loss of the KTN film sintered at 750 ℃ and room temperature showed good properties of about 2850 and 0.573, respectively, and all films exhibited the typical dielectric relaxation characteristics. The phase transition temperature of KTN thin film was around 12-13 ℃. Remanent polarization and the coercive field of KTN film sintered at 750 ℃ showed excellent properties of 23.98 μC/cm2 and 35.41 kV/cm, respectively. Adiabatic temperature changes (ΔT) and electrocaloric strength of the KTN films sintered at 750 ℃ at 60 ℃ were 2.67℃ and 0.012 KcmkV-1, respectively.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.32 no.3
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• pp.114-123
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• 2024

Recently, urban population congestion has caused significant traffic and air pollution problems in city centers. To address these issues, Urban Air Mobility (UAM) has been proposed, with commercialization targeted for 2025 in Korea. The Korea Meteorological Administration (KMA) has been conducting the K-UAM Grand Challenge in Goheung since 2022 to develop operational standards and relevant technologies. This study uses a ultrasonic anemometer at a height of 10 meters to analyze turbulence around the vertiport. Data was collected from November 2022 to November 2023. For turbulence analysis, the Eddy Dissipation Rate (EDR = ε^1/3), defined by the International Civil Aviation Organization (ICAO), was used. EDR was calculated using Kolmogorov's theory and derived from the energy spectrum. EDR values were classified into None, Light, Moderate, and Severe, and analyzed by season, day, and wind direction. The results showed strong daytime turbulence in summer, especially with southerly winds in spring and summer, due to sea breeze fronts. This study provides essential data for planning safe UAM operations considering weather conditions.

• Molecular Medicine Reports
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• v.19 no.3
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• pp.1809-1816
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• 2019

The extract of Sappan Lignum, the heartwood of Caesalpinia sappan L., has been used in medicine to improve blood circulation. Recently, the application of microwave extraction methods has been a major focus of research into the extraction of components from natural sources. In this experiment, we compared the anti-inflammatory effects of Sappan Lignum prepared by heat-70% EtOH extraction (CSE-H-70E) and microwave-70% EtOH extraction (CSE-MW-70E). High-performance liquid chromatography analysis was used to identify the compounds in these extracts. The heat-70% EtOH and microwave-70% EtOH extracts of Sappan Lignum had different chromatograms. CSE-MW-70E significantly inhibited the protein expression of iNOS and COX-2, PGE2, TNF-α, and reduced NO and IL-1β production in macrophages exposed to LPS, whereas, only high concentrations of CSE-H-70E (20 ㎍/ml) resulted in any effects. Furthermore, CSE-MW-70E upregulated heme oxygenase-1 (HO-1) expression. In addition, the use of tin protoporphyrin, an inhibitor of HO-1, confirmed the inhibitory effects of CSE-MW-70E on pro-inflammatory mediators. These results suggested that the CSE-MW-70E-mediated upregulation of HO-1 played an important role in the anti-inflammatory effects of macrophages. Therefore, these findings showed that microwave extraction can be utilized to improve the extraction efficiency and biological activity of Sappan Lignum.

• Journal of Ceramic Processing Research
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• v.21
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• pp.16-22
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• 2020

We fabricated SiC-TiC composites by hot-press sintering with aluminum and yttrium nitrate additive and evaluated crystal phase, relative density, microstructure, electrical resistivity and mechanical properties of the sintered body. And the effect of nitrate additive on the densification of SiC-TiC composites was compared with that of Al₂O₃ and Y₂O₃ additives. Because nitrate additives were uniformly dispersed in SiC and TiC mixture, it inhibited the growth of crystal grain between each other and formed fine and uniform microstructure, thereby improving mechanical properties and electrical resistivity. The electrical resistivity and flexural strength of the SiC-TiC composite with aluminum and yttrium nitrate additive were 2.3 Ω·cm and 652.3 MPa respectively.

• Korean Journal of Microbiology
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• v.43 no.1
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• pp.31-39
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• 2007

This study has been carried out for investigating the relatedness of representative 135 Shigella sonnei strains isolated from 2000 to 2004 by using biotyping and antimicrobial resistance. All strains showed typical biochemical characterisics of Shigella strain. Among 135 strains,79 (58.5%) strains were biotype "g",54 (40.0%) strains were biotype "a" and 2 (1.5%) strains were biotype "e". The results of susceptibility test against 16 antimicrobial agents were like this. Most of strains were susceptible to AN, CIP, C and GM. 129 (95.6%) strains were resistant to SXT, 126 (93.3%) strains were resistant to TE and 122 (90.4%) strains were resistant to SM. One hundred thirty two (97.8%) strains were resistant to more than two antimicrobial agents. R28 type (antimicrobial resistance patterns 28: resistant to AM, SAM, TE, TIC, SXT, K, SM and AmC) were 42 strains (31.1%). The other strains were showed 33 kinds of R patterns. The results of $bla_{TEM}$, sulII, tetA and strA gene detection were coincided with phenotype of antimicrobial resistance by disk diffusion method. But some strains which had sulII and strA genes were not showed the resistance against SXT and SM.

• Journal of Preventive Medicine and Public Health
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• v.29 no.3 s.54
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• pp.639-655
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• 1996

Cerebrovascular disease and coronary heart disease are the first and the fourth common causes of death among adults in Korea. Reported risk factors of these diseases are mostly alike. But some risk factors of one of these diseases may prevent other diseases. Therefore, we tried to compare and discriminate the risk factors of these diseases. We recruited four case groups and four control groups among the inpatients who were admitted to Wonju Christian Hospital from March, 1994 to November, 1995. Four control groups were matched with each of four case groups by age and sex. The number of patients in each of four case and control groups were 106 and 168 for acute myocardial infarction(AMI), 84 and 133 for subarachnoid hemorrhage(SAH), 102 and 148 for intracerebral hemorrhage(ICH), and 91 and 182 for ischemic stroke(IS) respectively. Factors whose levels were significantly higher in AMI and IS than in responding control group (RCG) were education, economic status, and triglyceride. Factors whose levels were significantly lower in hemorrhagic stroke than in RCG were age of monarch, and prothrombin time. The factor whose level was higher in AMI than ill RCG was uric acid. The factor whose level was higher in AMI, ICH, and SAM than in RCG was blood sugar. Factors whose levels were significantly higher in all the case groups than in RCG were earlobe crease, Quetelet index, white blood cell count, hemoglobin, hematocrit, and total cholesterol. The list of risk factors were somewhat different among the four diseases, though none of the risk factors to the one disease except prothrombin time acted as a preventive factor to the other diseases. The percent of grouped cases correctly classified was higher in the discrimination of ischemic diseases(AMI and IS) from hemorrhagic diseases(SAM and ICH) than in the discrimination of cerebrovascular disease from AMI. The factors concerned in the discrimination of ischemic diseases from hemorrhagic diseases were prothrombin time, earlobe crease, gender, age, uric acid, education, albumin, hemoglobin, the history of taking steroid, total cholesterol, and hematocrit according to the selection order through forward selection.