• Clinical and Experimental Pediatrics
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• v.48 no.4
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• pp.376-379
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• 2005

Purpose : Mycoplasama pneumoniae is a leading cause of pneumonia and exacerbates other respiratory conditions such as asthma. Surfactant protein A(SP-A) is involved in surfactant physiology and surfactant structure, and plays a major role in innate host defense and inflammatory processes in the lung. In this study, SP-A mediated mycoplasma cidal activity. The candidate-gene approach was used to study the association between the SP-A gene locus and Mycoplasama pneumoniae pneumonia in the genetically homogeneous Korean population. Methods : PCR-cRFLP-based methodology was used to detect SP-A genotype. The forty nine children with Mycoplasama pneumoniae pneumonia were matched to 50 nomal neonates. Results : The specific frequencies for the alleles of the SP-A1 and SP-A2 gene in the study population were : $6A^2=21$ percent, $6A^3=45$ percent, $6A^4=11$ percent, $6A^8=9$ percent, $6A^{14}=8$ percent, 1A=11.3 percent, $1A^0=38$ percent, $1A^1=12.7$ percent, $1A^2=9.2$ percent, $1A^5=15.5$ percent, $1A^7=2.9$ percent, $1A^8=4.9$ percent, $1A^9=2.2$ percent, others=3.3 percent. The frequencies of specific genotypes such as $1A^2$ was higher than control group, significantly. Conclusion : $1A^2$ are susceptible factors for Mycoplasama pneumoniae pneumonia. We conclude that the SP-A gene locus($1A^2$) is an important determinant for predisposition to Mycoplasama pneumoniae pneumonia in children.

• Journal of the Korean Society of Radiology
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• v.18 no.2
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• pp.101-108
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• 2024

Recently, Metaverse technology has emerged as an important topic in various fields. Metaverse refers to a three-dimensional virtual space in which social and economic activities similar to the real world are possible. Among the 235 third-year students who applied the Metaversity app in the radiology department of this university from September to December 2023, 200 participated in a survey to determine the difference in student response and satisfaction when applying the Metaversity app. analyzed. First, the most satisfactory VOD viewing method was viewing through the Metaversity app, followed by viewing through the LMS. Second, 'I think online videos are appropriate for holiday reinforcement.' showed the highest score at 4.35±0.60, 'I want face-to-face classes and online classes to be held simultaneously.' was 4.25±0.87, and 'I think meta. 'I watched it well through the Metaversity app' was the lowest at 4.10±0.30, and 'VOD viewing through the Metaversity app was used appropriately in class' was the lowest at 3.99±0.75. Also, there was no significant difference in the response to the teaching method (p>0.05). Third, in terms of satisfaction with VOD viewing using the Metaversity app, 'Applying the Metaversity app was interesting and fun' ranked the highest at 4.24±0.88. The score was high, with 'Better improvement is needed to actively utilize the metaversity app' at 4.00±0.45, and 'I hope the metaversity app is implemented in other remote classes' at 3.77±0.88. appear. 'VOD classes through the Metaversity app are better than the existing LMS method.' was found to be 3.44±0.66. Additionally, there was no significant difference in satisfaction with classes according to age and gender (p>0.05). The correlation between response and satisfaction with the metaversity app is 0.601, which can be considered very significant (p>0.001). As a limitation of this study, although we surveyed students' satisfaction with using the Metaversity app, we were unable to investigate the satisfaction of instructors who interact with students. In the future, we did not consider the instructor's satisfaction in classes using the Metaversity app. Research must be conducted, and universities must have institutional support and continued interest until metaversity apps are selected and used to prepare for distance learning.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.2
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• pp.518-524
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• 2003

Ultrasonic nebulizer with the application of new engineering methodology and the design of electronic circuit was made for lead inhalation toxicology study and 2730ppm lead nebulizing solution was used to generate lead aerosol. After modification of source and inlet temperatures, the results of particle size analysis for lead aerosol were as following. The highest particle counting for source temperature 20℃ was 39933.66 in inlet temperature 100℃ and particle diameter 0.75tLm. The highest particle counting for source temperature 50℃ was 39992.71 in inlet temperature 250℃ and particle diameter 0.75μm. The highest particle counting for source temperature 70℃ was 37569.55 in inlet temperature 50℃ and particle diameter 0.75μm. The ranges of geometric mean diameter(GMD) were 0.754-0.784μm for source temperature 2℃, 0.758-0.852μm for source temperature 50℃, and 0.869-1.060μm for source temperature 70℃. The smallest GMD was 0.754μm in source temperature 20℃ and inlet temperature 20℃, and the largest GMD was 1.060μm in source temperature 70℃ and inlet temperature 250℃. The ranges of geometric standard deviation(GSD) were 1.730-1.782 for source temperature 20℃, 1.734-1.894 for source temperature 50℃, and 1.921-2.148 for source temperature 70℃. The lowest GSD was 1.730 in source temperature 20℃ and inlet temperature 20℃, and the highest GSD was 2.148 in source temperature 70℃ and inlet temperature 250℃. Lead aerosol generated in this study was polydisperse. The ranges of mass median diameter(MMD) were 1.856-2.133μm for source temperature 20℃, 1.877-2.894μm for source temperature 50℃, and 3.120-6.109μm for source temperature 70℃. The smallest MMD was 1.856μm in source temperature 20℃ and inlet temperature 20℃, and the largest MMD was 6.109μm in source temperature 70℃ and inlet temperature 250℃. Slight increases for GMD, GSD, and MMD values were observed with same source temperature and increase of inlet temperature. MMD for inhalation toxicology testing in EPA guidance is less than 4μm. In this study, source temperature 20℃ and 50℃ with inlet temperature from 20℃ to 250℃ were conformed to the EPA guidance, but inlet temperature 20℃ and 50℃ for source temperature 70℃ were conformed EPA guidance. MMD for inhalation toxicology testing in OECD and EU is less than 3μm. In this study, source temperature 20℃ and 50℃ with inlet temperature from 20℃ to 250℃ were conformed to the EPA guidance, but none for source temperature 70℃.

• Korean Journal of Environmental Biology
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• v.35 no.3
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• pp.389-397
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• 2017

The purpose of this study was to investigate the characteristics of species by comparing the external shape traits and skull size of Tscherskia triton in Jeju Island from May 2014 to November 2016. Body weight, head-body length, ear length, and hind-foot length were not statistically significant (p>0.05), but tail length was statistically significant in females compared to males (p=0.003). To examine the secondary sexual dimorphism characteristics of the collected T. triton, B_HR, T_HR, E_HR, and H_HR were calculated based on the head-body length, and only T_HR was statistically significant (p=0.003). Because of comparing male and female averages, among the 21 traits, the greatest length of skull (GLS; p=0.020) and occipitonasal length (ONL; p=0.014) were statistically significant and length of incisive foramen (LIF) was statistically significant, when the significance level was 90%. However, the other 18 traits did not show statistically significant differences between males and females (p>0.05). Other than GLS, ONL, interorbital breadth (IB), and breadth of occipital foramen (BOF), there was female-biased SSD. The results of this study are the analysis of external morphology and skull characteristics of T. triton in Jeju Island and will be used as basic data to understand the morphological characteristics of T. triton. In addition, the data can be used as a basic information to compare characteristics of T. triton, which is known as a single species, inhabited in China and Russia. The data will play an important role in biogeography and ecology research of T. triton, based on geographical conditions, climate effects, and habitat environment.

• Journal of Animal Science and Technology
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• v.44 no.2
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• pp.251-260
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• 2002

The corn (Zea mays L) planting date in a double-cropping system is delayed until mid-May due to delayed rye harvest on May. This experiment was conducted to determine the optimum harvesting time for high yield and the best quality of silage corn at late planting date after harvesting winter rye. Corns were planted on 21 May and harvested at eight different maturity stage at Seoul National University Experimental Livestock Farm, Suwon in 1997. Maturities were B (blister; 16 days after silking), M (milk; 20 days), LM (late milk; 24 days), SD (soft dough; 28 days), ED (early dent; 33 days), FD (full dent; 38 days), LD (late dent; 44 days) and PM (physiological maturity; 53 days) stages. The percentage of whole plant dry matter (DM) showed optimum range for silage making (29.0 to 38.5%) when corn plant was harvested at between ED and LD stages. Maximum whole plant DM (14,831 kg/ha) and total digestible nutrients (TDN) yields (10,675 kg/ha) reached at full dent stage. The percentage of whole plant acid detergent fiber (ADF) was decreased from 35.4 to 22.1%, and that of neutral detergent fiber (NDF) was also decreased from 63.8 to 46.0% as harvest stage progressed. These changes in chemical compositions were associated with changes in plant part composition. A progressive increase in total ear, and the decrease in stover portion in the plant were observed with advance in harvest stage. Calculated on net energy for lactation (NEL) and TDN values based on ADF percentage of stover plant decreased by ED stage and then increased by PM stage. But NEL and TDN values of ear and whole plant increased as harvest stage progressed. While in vitro dry matter digestibility of stover was decreased from 61.1 to 49.7%, whole plant was increased from 58.3 to 65.7% as maturity advanced (P$<$0.05). The results of this study indicate that corn can be harvested for silage at full (1/2 milkline) and late dent (2/3 milkline) stages for maximum yield and optimum quality at late planting. And days after silking at late planting was 38 and 44 days.

• Microbiology and Biotechnology Letters
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• v.37 no.4
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• pp.389-398
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• 2009

Development of expression vectors is important for the basic and applied researches on kimchi LAB (lactic acid bacteria). An expression vector, pSJE6c was constructed by inserting P6C promoter sequence from Lactococcus lactis into pSJE, a shuttle vector for E. coli and Leuconostoc species. To test the efficiency of pSJE6c, aga ($\alpha$-galactosidase) and lacZ ($\beta$-galactosidase) genes were expressed in Lactobacillus brevis 2.14. Compared to the pSJE, expression levels of both genes were increased, indicating P6C promoter was better than indigenous promoters. Enzyme activities of L. brevis cells harboring pSJE6caga (pSJE6c with aga) or pSJE6Z (pSJE6c with lacZ) were 1.5-2 fold higher than those with pSJEaga (pSJE with aga) or pSJEZ (pSJE with lacZ). More RNA transcripts were detected in cells harboring pSJE6c based recombinant plasmid. The results indicated that heterologous gene expressions in kimchi LAB could be improved significantly by use of efficient expression vectors.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.3
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• pp.380-385
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• 1998

This study evaluated the possible utilization and the replacing range of animal by-product mixture (ABPM) as a dietary fish meal replacer in growing common carp (Cyprinus carpio). ABPM is a mixture of leather meal, meat and bone meal, blood meal and squid liver powder at a specific weight based ratio. Five different diets were formulated on isonitrogenous and isocaloric basis of $40\%$ crude protein and 15.3 KJ/g diet in which white fish meal (WFM) protein was substituted with the ABPM Protein as follows: diet 1, $100\%$ WFM ($0\%$ ABPM, control); diet 2, $75\%$ WFM+$25\%$ ABPM ($25\%$ ABPM); diet $3,\;50\%$ WFM+$50\%$ ABPM ($50\%$ ABPM); diet 4 $25\%$ WFM+$75\%$ ABPM ($75\%$ ABPM); diet $5.0\%$ WFM+$100\%$ ABPM ($100\%$ ABPM). As the dietary protein sources, each diet contained $34.7\%$ of animal protein supplied by white fish meal and/or ABPM and $65.3\%$ of plant protein. After one week of conditioning period, fish averaging 10 g were randomly assigned to each diet treatment as triplicate groups and fed one of the experimental diets for 12 weeks. Weight gain of fish fed diet 1 (control) and 3 were significantly higher than those of fish fed diet 2, 4 and 5 during the first 4 weeks (P< 0.05), while there were no significant differences among all diet groups during the third 4 weeks (P>0.05). Feed conversion ratio of fish fed diet 1 was significantly higher than those fed diet 2, 3, 4 and 5 during the second 4 weeks (P<0.05), while there were no significant differences among all diet groups during the first and the third 4 weeks (P<0.05). There were no significant differences in proximate analysis among fish fed the experimental diets either for the second 4 weeks or the third 4 weeks (P>0.05). These results indicated that ABPM could be used as a fish meal replacer up to $100\%$ in growing common carp.

• Journal of Plant Biology
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• v.38 no.1
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• pp.95-105
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• 1995

Complete microsporogenesis of Hibiscus syriacus L. were carried out employing LM, TEM, and SEM to investigate the pollen ontogeny that undergoes considerable structural differentiation. The process first began with several cell diYisions in the anther primordium that produces 3 different tissues of epidennal, archesporial, and connective tissues. Only archesporial tissue involved further differentiation into the tapetum and formation of reproductive cells, pollen mother cells (PMC). The tapetum and PMC were closely associated with each other structurally and metabolically by exhibiting numerous plasmodesmata, mitochondria, and many small vacuoles in their dense cytoplasm. A callosic wall began to surround the PMC while meiosis took place in the PMC to produce 4 microspores. When thick callose encircled each microspore as a frame, the sporodenn development initiated from the plasma membrane of a pollen grain in a tetrad. The first fonned sporoderm layer was bacules and tectum of sexine that originated from the plasma membrane. After the dissolution of a callose, further development Qf sporoderm continued in the order of nexine 1, nexine 2, and intine layer. The nexine layer was thicker (ca. $2-3.5\;\mu\textrm{m}$) than the intine layer whose thickness was about $0.9-1.5\;\mu\textrm{m}$. Upon completion of the sporoderm development, that is after intine formation, spines and apertures of pollen surface ornamentation initiated from the tectum. Spines were dimorphic, about $4-9\;\mu\textrm{m}\;an;15-20\;\mu\textrm{m}$ in length, and no basal cushion was detected. The mature pollen grains ranged $100-200\;\mu\textrm{m}$ in diameter, but their average was about $170\;\mu\textrm{m}$. About 120 spines were observed over the spheroidal pollen surface. Apertures were simple punctures of $2-3\;\mu\textrm{m}$ in diameter and about 50 apertures were arranged somewhat helically over the surface. Comparing such features of form and size of the pollen, sporodenn sculpture and structure, and aperture and spine conditions with known evolutionary trends in the genus Hibiscus, Hibiscus syriacus seemed to possess many advanced features in the sporodenn differentiation.iation.

• Korean Journal of Materials Research
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• v.4 no.7
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• pp.759-766
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• 1994

Our investigation aimed to reduce the leakage current of $Ta_2O_5$ thin film capacitor by layering SnOz thin film layer under Ta thin film, thereby supplying extra oxygen ions from the $SnO_{2}$ underlayer to enhance the stoichiometry of $Ta_2O_5$ during the oxidation of Ta thin film. Tantalum was evaporated by e-beam or sputtered on p-Si wafers with various deposition temperatures and was oxidized by dry--oxygen at the temperatures between $500^{\circ}C$ and $900^{\circ}C$. Aluminum top and bottom electrodes were formed to make Al/$Ta_2O_5$/p-Si/Al or $Al/Ta_2O_5/SnO_2$p-Si/AI MIS type capacitors. LCR meter and pico-ammeter were used to measure the dielectric constants and leakage currents of the prepared thm film capacitors. XRD, AES and ESCA were employed to confirm the crystallization of the thin f~lm and the compositions of the films. Dielectric constant of $Ta_2O_5$ thin film capacitor with $SnO_{2}$ underlayer was found to be about 200, which is about 10 times higher than that of $Ta_2O_5$ thin film capacitor without $SnO_{2}$ underlayer. In addition, higher oxidation temperatures increased the dielectric constants and reduced the leakage current. Higher deposition temperature generally gave lower leakage current. $Ta_2O_5/SnO_2$ capacitor deposited at $200^{\circ}C$ and oxidized at $800^{\circ}C$ showed significantly lower leakage current, $10^{-7}A/\textrm{cm}^2$ at $4 \times 10^{5}$V/cm, compared to the one without $SnO_{2}$ underlayer. XRD showed that $Ta_2O_5$ thin film was crystallized above $700^{\circ}C$. AES and ESCA showed that initially the $SnO_{2}$, underlayer supplied oxygen ions to oxidize the Ta layer, however, Sn also diffused into the Ta thin film layer to form a new $Ta_xSn_YO_Z$ , ternary oxide layer after all.

• Korean Journal of Plant Taxonomy
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• v.32 no.3
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• pp.339-362
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• 2002

Pollen morphology of 13 species of Korean Euphorbia was re-examined by means of LM and SEM. Taxonomic evaluation of palynological characters and relationships among taxa were also discussed based on the analysis of polar length, equatorial diameter, aperture size and exine thickness. Korean Euphorbia species were classified into three groups based on the mean size of polar length (P) and equatorial diameter (E) as follows:Group 1. sect. Tulocarpa and Tithymalus of subgenus Esula; $(P){\times}(E)=(54.88-67.17{\mu}m){\times}(44.30-64.75{\mu}m)$, Group 2. sect. Esula and Helioscpiae of subgenus Esula; $(P){\times}(E)=(39.98-47.24{\mu}m){\times}(36.07-38.83{\mu}m)$, Group 3. sect. Chamaesyce and Hypericifoliae of subgenus Chamaesyce; $(P){\times}(E)=(30.32-32.51{\mu}m){\times}(21.71-26.23{\mu}m)$. Various features of surface sculpturing were also grouped into 8 types by the characteristics of perporation size and distance of perporations as well as connection state of it. Pollen size and surface sculpturing were comparatively available in the levels of subgenus and section. Especially subgenus Chamaesyce was distinctly different from subgenus Esula by having compactly distributed perporations on exine surface as well as its small size of pollen grains. Because of the great variations in pollen size and the occurrence of various types of surface sculpturing according to the local poulations of each species, it was evaluated that they were unsuitable in classifying each species of Euphorbia. But such cases, that is, E. hylonoma being more familiar with E. ebracteolata than E. Pallasii, and E. pekinensis and E. fauriei as well as E. pallasii being strongly related with each other based on the similarity of surface sculpturing, reflected its usefulness in the classification of some Euphorbia species.