• Korean journal of applied entomology
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• v.58 no.2
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• pp.89-99
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• 2019

In total, 654,362 adult mosquitoes were captured using black light traps in Gangwon-do Province of the Republic of Korea from 2012 to 2017. The collected mosquitoes were identified to the species level, placed in pools of up to 50 mosquitoes each, by species and date of collection, and screened for flaviviruses using a reverse transcription-polymerase chain reaction assay. A total of 276,224 adult mosquitoes were grouped in 7,721 pools for virus testing, and 68 flavivirus positive pools (0.9%) were detected. Flavivirus-positive products were confirmed by DNA sequencing. Japanese encephalitis viruses were detected in single pools collected from Chuncheon (2012, 2017: Culex pipiens, 2,728 and 1,111 mosquitoes, respectively), Hoengseong (2013: Culex orientalis, 19), and Gangneung (2017: C. pipiens, 724). All the Japanese encephalitis viruses detected were revealed as genotype V. Chaoyang viruses were detected in 63 pools of 5,055 Aedes vexans nipponii and a single pool of 585 C. pipiens collected in Gangwon-do Province from 2012 to 2017. Chuncheon was the region with the highest minimum infection rates (MIR, 0.32) and maximum likehood estimate (MLE, 0.33; confidence interval (CI) 95%, 0.23-0.46) of A. vexans nipponii for Chaoyang virus, followed by Hoengseong (MIR 0.30, MLE 0.30, CI 0.16-0.52) and Gangneung (MIR 0.21, MLE 0.21, CI 0.13-0.31). Monthly MIR and MLE values of A. vexans nipponii for Chaoyang virus were the highest in October (MIR 0.38, MLE 0.38, CI 0.07-1.25).

• Economic and Environmental Geology
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• v.55 no.1
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• pp.77-95
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• 2022

The Gonamsan gabbroic complex in the Pocheon area, northwestern region of South Korea consists of a variety types of gabbroic rocks and associated Fe-Ti oxide deposits caused by magmatic differentiation. Post-magmatic intrusions (i.e., gabbroic pegmatite and pyroxene-apatite-zircon rocks) partly intruded into the gabbroic rocks. The gabbroic pegmatite occurs in monzodiorite and oxide gabbro of the complex, intimately and spatially associated with high-grade lenticular Fe-Ti oxide mineralization. The pegmatite can be subdivided into plagioclase-amphibole and pyroxene-olivine pegmatite, in which the contact surface is sharp. The plagioclase-amphibole pegmatite comprises plagioclase and amphibole, with lesser amount of pyroxene, ilmenite, sphene, apatite, and biotite. The pegmatite shows plagioclase-amphibole intergranular texture, in which the open space formed by large plagioclase laths (An_2-26Ab_72-98Or_0-2) are infilled by amphibole. The pyroxene-olivine pegmatite is dark gray to black in color and also contains magnetite, ilmenite, spinel, apatite, and calcite as a minor component. The pyroxene (En_35-36Fs_8-9Wo₅₅) and olivine (Fo_84-85Fa_15-16) partly show a poikilitic texture defined by smaller euhedral olivine enclosed by coarser clinopyroxene. Fe-Ti oxide minerals consist mainly of magnetite and ilmenite that are found interstitially to earlier formed silicates. Subsequently, they are encompassed by reaction rim (almost of amphibole and biotite) along the boundary with surrounding silicate minerals. Under the microscope, magnetite contains a lot of oxyexsolved ilmenite (trellis type) and spinel, and thereby is weakly enriched in magnetite-compatible elements such as Ti, Al, Mg, and V. The structure and textures at the contact zone as well as mineralogical disequilibrium between gabbroic pegmatite and the host gabbroic rocks suggest that the pegmatite may form as a result of accumulation from Fe-rich melt (or liquid) that occurred somewhere rather than in situ form from the host gabbroic rock during the magmatic differentiation. Consequently, the preliminary study suggests that further study on the post-magmatic activities can not only help us improve our understanding on magmatic fractionation but also provide critical information on Fe-Ti oxide mineralization in gabbroic rocks resulting from the magmatic differentiation.

• Journal of The Korean Association For Science Education
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• v.29 no.8
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• pp.923-933
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• 2009

In this study, analysis was carried out on science experiment in high school textbooks, illustrating 'the effect of pH on enzyme activity.' Five of the total 16 science textbooks introduced in this experiment, and the experimental conditions therein were analyzed. Textbook analysis revealed that pH of below 3 was used for 'acidic condition' and that of over 11 was used for 'basic' condition. Using the experimental conditions described in the textbooks, review experiments were performed. Buffering effect with the addition of saliva was found in the pH region around 7 when buffer solution was not used to control pH as was in the textbooks. The enzyme activity experiments were performed controlling pH from pH 2 to 13 with buffer. The color of the sample was blue from pH 2 to 4, and then disappeared from pH 5 to 8, reflecting that starch was digested owing to enzyme activity. In pH 9 light blue color appeared, indicating de-activation of enzyme under this basic condition. However, the blue color of the sample became lighter at pH 10 and disappeared from pH 11, which was different from the expected behavior anticipating dark blue color due to de-activation of enzyme under strong basic condition. These results can wrongly influence students to interpret that enzyme can be activated in this pH condition. So, we analyzed the reason for the color of the sample turning light blue in pH 10 and disappeared from pH 11. The analysis resulted that ${I_3}^-$ and/or ${I_5}^-$ subunits of polyiodides within the starch helix in starch-iodine complex, showing blue, decreases above pH 10 due to disproportionation to HOI, ${IO_3}^-$, and $I^-$ by the reaction with $OH^-$.

• Restorative Dentistry and Endodontics
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• v.36 no.6
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• pp.498-505
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• 2011

Objectives: The purpose of this in vivo study was to investigate the microbial diversity in symptomatic and asymptomatic canals with primary endodontic infections by using GS FLX Titanium pyrosequencing. Materials and Methods: Sequencing was performed on 6 teeth (symptomatic, n = 3; asymptomatic, n = 3) with primary endodontic infections. Amplicons from hypervariable region of the small-subunit ribosomal RNA gene were generated by polymerized chain reaction (PCR), and sequenced by means of the GS FLX Titanium pyrosequencing. Results: On average, 10,639 and 45,455 16S rRNA sequences for asymptomatic and symptomatic teeth were obtained, respectively. Based on Ribosomal Database Project Classifier analysis, pyrosequencing identified the 141 bacterial genera in 13 phyla. The vast majority of sequences belonged to one of the seven phyla: Actinobacteria, Bacteroidetes, Firmicutes, Fusobacteria, Proteobacteria, Spirochetes, and Synergistetes. In genus level, Pyramidobacter, Streptococcus, and Leptotrichia constituted about 50% of microbial profile in asymptomatic teeth, whereas Neisseria, Propionibacterium, and Tessaracoccus were frequently found in symptomatic teeth (69%). Grouping the sequences in operational taxonomic units (3%) yielded 450 and 1,997 species level phylotypes in asymptomatic and symptomatic teeth, respectively. The total bacteria counts were significantly higher in symptomatic teeth than that of asymptomatic teeth (p < 0.05). Conclusions: GS FLX Titanium pyrosequencing could reveal a previously unidentified high bacterial diversity in primary endodontic infections.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.18 no.6
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• pp.253-257
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• 2008

To enhance the luminescence properties, the red phosphor composed of $(Y,\;Zn)_2O_3$:$Eu^{3+}$ as doping concentration of Zn ion is synthesized at $1200^{\circ}C$ for 6 hrs in air atmosphere by conventional solid reaction method. As a result of the red phosphor $(Y,\;Zn)_2O_3$:$Eu^{3+}$ is measured X-ray diffraction (XRD), The main peak is nearly corresponded to the same as JCPDS card (No. 41-1105). When the doping concentration of Zn ion is more than 5 mol%, However, the ZnO peak is showed by XRD analysis. Therefore, when the doping concentration of Zn ion is less than 5 mol%, the Zn ion is well mixed in $Y_2O_3$ structure without the impurity phases. The photoluminescence (PL) properties is shown as this phosphor is excited in 254 nm region and the highest emission spectra of $(Y,\;Zn)_2O_3$:$Eu^{3+}$ has shown in 612 nm region because of a typical energy transition ($^5D_0{\rightarrow}^7F_2$) of $Eu^{3+}$ ion. As the doping concentration of Zn ion is more than 10 mol%, the emission peak is suddenly decreased. when the highest emission peak as doping concentration of Zn ion is shown, the composition of this phosphor is $(Y_{0.95},\;Zn_{0.05})_2O_3$:$Eu^{3+}_{0.075}$ and the particle size analyzed by FE-SEM is confirmed from 0.4 to $3{\mu}m$.

• Tuberculosis and Respiratory Diseases
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• v.60 no.2
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• pp.160-170
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• 2006

Background : The aberrant promoter hypermethylation of p16INK4a, as a tumor suppressor gene, is contributory factor to non-small cell lung cancer(NSCLC). However, its potential diagnostic impact of lung cancer is unclear. This study measured the level of $p16^{INK4a}$ promoter hypermethylation in the sputum and blood, and compared this with the level measured in the tissue obtained from NSCLC and pulmonary inflammation. Methods : Of the patients who visited the Our Lady of Mercy Hospital in Incheon, Korea for an evaluation of a lung mass and underwent blood, sputum, and tissue tests, 23patients (18 NSCLC, 5 pulmonary inflammation) were enrolled in this study. DNA was extracted from each sample and the level of p16INK4amethylation was determined using methylation-specific polymerase chain reaction. Results : $p16^{INK4a}$ methylation of the blood was observed in 88.9% (16 of 18) and 20.0% (1 of 5) of NSCLC and from pulmonary inflammation samples, respectively (P=0.008). Methylation of the sputum was observed in 83.3% (10 of 12) 80.0% (4 of 5) of NSCLC and pulmonary inflammation samples, respectively (P=1.00). Among the 8 NSCLC tissue samples, methylation changes were detected in 75.0% of samples (6 cases). Four out of seven tissue samples (57.1%) showed concordance, being methylated in both the blood and sputum. Conclusions : There was a higher level of $p16^{INK4a}$ methylation of the blood from NSCLC patients than from pulmonary inflammation. The tissue showed a high concordance with the blood in the NSCLC samples. These findings suggest that $p16^{INK4a}$ promoter hypermethylation of the blood can used to discriminate between NSCLC and pulmonary inflammation.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.3
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• pp.362-371
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• 2004

It is essential to have adequate knowledge of the timing of root resorption of deciduous teeth for diagnosis and treatment planning in pediatric and orthodontic dentistry. Dental development is also influenced by hereditary characteristics, environmental factors, race, sex, endocrine reaction, nutrition, socioeconomic condition and secular factor. The aims of the present study were to determine the mean age of root resorption of deciduous teeth in contemporary Korean children and to compare the mean age of root resorption time of deciduous teeth between early 1990s and early 2000s. The study population was made up of Korean children attending the pediatric dentistry ward of Kyungpook National University Hospital. One thousand thirty seven children's panoramic radiograph (girls: 528 persons, boys: 509 persons) in $1990{\sim}1992$ and one thousand sixty five children's panoramic radiograph (girls: 394 persons, boys: 671 persons) in $2001{\sim}2003$ were examined. This study utilized a cross-sectional design. Due to the problems of imaging in the maxillary region and the mandibular incisor region, the mandibular deciduous canine, the mandibular deciduous first molar and the mandibular deciduous second molar were chosen for examination. The results were as follows. 1. There is a tendency for the teeth to resort earlier in the early 2000s group than the in early 1990s group. At the Res c stage, the difference of the mean age was 0.4 years. 2. At the Res c stage, the order of difference of the mean age from smaller to larger for the girls was the mandibular deciduous canine, the mandibular first deciduous molar, and the mandibular second deciduous molar. On the other hand, for the boys, the order was the mandibular second deciduous molar, the mandibular first deciduous molar, and the mandibular deciduous canine. The difference was larger with aging in girls and smaller with aging in boys. 3. There is a tendency for the teeth to resort earlier in girls in both the early 1990s group and the early 2000s group. The difference of the mean age between girls and boys was 0.3 year. 4. The commencement of root resorption of the mandibular deciduous canine was slower than that of the mandibular first deciduous molar. However, the completion of root resorption of the mandibular deciduous canine is faster than that of the mandibular first deciduous molar. The total elapsed time of root resorption from commencement to completion was shortest in the mandibular deciduous canine. 5. For each of the teeth in the early 1990s and the early 2000s groups, the speed of root resorption was in the later stage faster than in the earlier stage. In order to know about the exact timing of root resorption of deciduous teeth, periodic and longitudinal studies preferably covering the entire period of growth, is required.

• Journal of the Korean Electrochemical Society
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• v.4 no.2
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• pp.58-64
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• 2001

YSZ ($8mol\%$ yttria-stabilized zirconia)-modified LSM $(La_{0.85}Sr_{0.15}MnO_3)$ composite cathodes were fabricated by formation of YSZ film on triple phase boundary (TPB) of LSM/YSZ/gas. The YSZ coating film greatly enlarged electrochemical reaction sites from the increase of additional TPB. The composite cathode was formed on thin YSZ electrolyte (about 30 Um thickness) supported on an anode and then I-V characterization and AC impedance analyses were performed at temperature between $700^{\circ}C\;and\;800^{\circ}C$. As results of the impedance analysis on the cell at $800^{\circ}C$ with humidified hydrogen as the fuel and air as the oxidant, R1 around the frequency of 1000 Hz represents the anode Polarization. R2 around the frequency of 100Hz indicates the cathode polarization, and R3 below the frequency of 10 Hz is the resistance of gas phase diffusion through the anode. The cell with the composite cathode produced power density of $0.55\;W/cm^2\;and\;1W/cm^2$ at air and oxygen atmosphere, respectively. The I-V curve could be divided into two parts showing distinctive behavior. At low current density region (part I) the performance decreased steeply and at high current density region (part II) the performance decreased gradually. At the part I the performance decrease was especially resulted from the large cathode polarization, while at the part H the performance decrease related to the electrolyte polarization.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1981.05a
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• pp.10-10
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• 1981

The thyroglossal duct cyst is relatively rare disease that derived congenitally from the remnant of thyroglossal duct and that was found anywhere from the foramen cecum to pyramidal lobe of thyroid. We studied the 62 cases of above disease who admitted and operated at E.N.T. dept. of N.M.C. for 20 years since 1961 to 1980 on the clinical and histopathological aspect, and we concluded following results. 1. In the age distribution, 45 cases(72.6%) were under 20 years, and in the age distribution of the known on-set of symptoms, 26 cases(58.0%) were under 10 years. In the duration, 23 cases(37.0%) were under 1 year. The sex ratio of male to female revealed 1.2:1. 2. The palpable mass were complained at 48 cases(77.4%) and 14 cases(22.6%) complained of the discharge from sinus tracts and the other complaints were dysphagia and odynophagia, etc. 3. In location 55 cases (88.7%) were at midline, 1 case(1.6%) was at right and 6 cases(9.7%) were left sided. And 47 cases(75.8%) were situated at infrahyoid region, 11 cases(17.7%) at suprahyoid, 3 cases(4.8%) at suprasternal, only 1 case(1.6%) at intralingual region. 4. In 27 cases formed fistulae, spontaneous occurrance were 7 cases and artificial occurrance were 20 cases. 5. In histopathologically among 41 cases preserving available slides, 5 cases(12.2%) had single duct and 20 cases(48.8%) had multiple accessory ducts, but 16 cases were impossible to detect the ducts. The lining epithelium composed of chiefly respiratory and squamous epithelium. 15 cases had inflammatory reaction at periductal area and 7 cases had around the cysts. The ectopic thyroid tissue was found on 6 cases(14.6%) and 1 case had the follicular adenoma. 6. In the recurrance rate among 43 cases performed sistrunk type operation, 2 cases (4.6%) recurred, and among 19 cases performed simple removal of cysts, 4 cases (21.1%) recurred.

• Korean Chemical Engineering Research
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• v.44 no.6
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• pp.659-668
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• 2006

The optimization of supercritical water oxidation (SCWO) process for decomposing nitromethane was studied by means of a design of experiments. The optimum operating region for the SCWO process to minimize COD and T-N of treated water was obtained in a lab scale unit. The authors had compared the results from a SCWO pilot plant with those from a lab scale system to explore the problems of scale-up of SCWO process. The COD and T-N in treated waters were selected as key process output variables (KPOV) for optimization, and the reaction temperature (Temp) and the mole ratio of nitromethane to ammonium hydroxide (NAR) were selected as key process input variables (KPIV) through the preliminary tests. The central composite design as a statistical design of experiments was applied to the optimization, and the experimental results were analyzed by means of the response surface method. From the main effects analysis, it was declared that COD of treated water steeply decreased with increasing Temp but slightly decreased with an increase in NAR, and T-N decreased with increasing both Temp and NAR. At lower Temp as $420{\sim}430^{\circ}C$, the T-N steeply decreased with an increase in NAR, however its variation was negligible at higher Temp above $450^{\circ}C$. The regression equations for COD and T-N were obtained as quadratic models with coded Temp and NAR, and they were confirmed with coefficient of determination ($r^2$) and normality of standardized residuals. The optimum operating region was defined as Temp $450-460^{\circ}C$ and NAR 1.03-1.08 by the intersection area of COD < 2 mg/L and T-N < 40 mg/L with regression equations and considering corrosion prevention. To confirm the optimization results and investigate the scale-up problems of SCWO process, the nitromethane was decomposed in a pilot plant. The experimental results from a SCWO pilot plant were compared with regression equations of COD and T-N, respectively. The results of COD and T-N from a pilot plant could be predicted well with regression equations which were derived in a lab scale SCWO system, although the errors of pilot plant data were larger than lab ones. The predictabilities were confirmed by the parity plots and the normality analyses of standardized residuals.