• IMMUNE NETWORK
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• v.20 no.5
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• pp.41.1-41.11
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• 2020

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) is a positive-sense single-stranded RNA (+ssRNA) that causes coronavirus disease 2019 (COVID-19). The viral genome encodes twelve genes for viral replication and infection. The third open reading frame is the spike (S) gene that encodes for the spike glycoprotein interacting with specific cell surface receptor - angiotensin converting enzyme 2 (ACE2) - on the host cell membrane. Most recent studies identified a single point mutation in S gene. A single point mutation in S gene leading to an amino acid substitution at codon 614 from an aspartic acid 614 into glycine (D614G) resulted in greater infectivity compared to the wild type SARS-CoV2. We were interested in investigating the mutation region of S gene of SARS-CoV2 from Korean COVID-19 patients. New mutation sites were found in the critical receptor binding domain (RBD) of S gene, which is adjacent to the aforementioned D614G mutation residue. This specific sequence data demonstrated the active progression of SARS-CoV2 by mutations in the RBD of S gene. The sequence information of new mutations is critical to the development of recombinant SARS-CoV2 spike antigens, which may be required to improve and advance the strategy against a wide range of possible SARS-CoV2 mutations.

• Journal of the Korean Applied Science and Technology
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• v.40 no.6
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• pp.1201-1212
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• 2023

This study aimed to analyze the changes in underwater anxiety and water safety consciousness among college students through participation in survival swimming education and the relationship between these changes and various factors. To achieve this, 200 college students who were participating in survival swimming education from universities located in the Busan-Ulsan-Gyeongnam region were selected as participants using convenience sampling. Among them, a final valid sample of 191 students was utilized. Data analysis was conducted using SPSS 25.0 statistical software, including exploratory factor analysis, reliability analysis, paired sample t-test, repeated measures ANOVA. The results are as follows: Firstly, college students who participated in survival swimming education showed a decrease in post-test underwater anxiety and an increase in water safety consciousness compared to pre-test. Secondly, the interaction between the groups based on the presence or absence of swimming education experience and time showed a significant effect only in the safety education, a sub-factor of water safety consciousness. Based on these results, the effectiveness of survival swimming education for college students could be confirmed, and further directions for expanding survival swimming education in university settings could be considered.

• Journal of the Korean Society of Radiology
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• v.84 no.5
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• pp.1110-1122
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• 2023

Purpose This study aimed to assess the variability of transrectal shear wave elastography (SWE) using a designed phantom. Materials and Methods In a phantom, the SWE values were examined by two radiologists using agarose and emulsion silicone of different sizes (1, 2, and 3 cm) and shapes (round, cubic) at three depths (1, 2, and 3 cm), two region of interest (ROI) and locations (central, peripheral) using two ultrasound machines (A, B from different vendors). Variability was evaluated using the coefficient of variation (CV). Results The CVs decreased with increasing phantom size. Significant changes in SWE values included; agarose phantom at 3 cm depth (p < 0.001; machine A), 1 cm depth (p = 0.01; machine B), emulsion silicone at 2 cm depth (p = 0.047, p = 0.020; both machines). The CVs increased with increasing depth. Significant changes in SWE values included; 1 cm agarose (p = 0.037, p = 0.021; both machines) and 2 cm agarose phantom (p = 0.047; machine A). Significant differences in SWE values were observed between the shapes for emulsion silicone phantom (p = 0.032; machines A) and between ROI locations on machine B (p ≤ 0.001). The SWE values differed significantly between the two machines (p < 0.05). The intra-/inter-operator agreements were excellent (intraclass correlation coefficient > 0.9). Conclusion The phantom size, depth, and different machines affected the variability of transrectal SWE.

• Ocean and Polar Research
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• v.34 no.4
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• pp.413-430
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• 2012

To understand the scales of the spatial distribution and temporal duration of the subsurface chlorophyll-a maximum (SCM) observed in the Ulleung Basin of the East Sea, we analyzed physical and chemical data collected during the East Asian Seas Time-series-I (EAST-I) program. The SCM layer occurred at several observation lines from the Korea Strait to $37.9^{\circ}N$ in the Ulleung Basin during August of 2008 and 2011. At each observation line, the SCM layer extended from the coast to about 200 km off the coast. The SCM layer was observed between 30 and 40 m depth in the Ulleung Basin as well as in the northwestern Japan Basin along $132.3^{\circ}E$ from $38^{\circ}N$ to $42.3^{\circ}N$ during July 2009, and was observed around 50 m depth in the northeastern Japan Basin ($135-140^{\circ}E$ and $40-45^{\circ}N$) during July 2010. From these observed features, we hypothesize that the SCM layer observed in the Ulleung Basin may exist in most of the East Sea and may last for at least half-year (from the early May to late October). The nutrient supply mechanism for prolonged the SCM layer in the East Sea was not known, but it may be closely related to the horizontal advection of the nutrient rich and low oxygen waters observed in the Korea Strait between a 50 m depth to near the bottom. The prolonged development of the SCM layer in the Ulleung Basin may result in high primary production and would also be responsible for the high organic carbon content observed in the surface sediment of the region.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.5 no.3
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• pp.88-96
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• 1972

1. The present paper deals with the contents of heavy metals such as mercury, cadmium, lead and copper in 17 species of edible seaweeds collected from Jumunjin, Pohang, Pusan, Chungmu, Yeosu and Wando areas. 2. The concentration of mercury in the air-dried seaweeds ranged from 0.02 to 0.52 ppm, as shown by the following species: 0.36ppm (0.09-0.50) in Enteromorpha spp., 0.25 ppm (0.14-0.31) in Undaria sp., 0.19 ppm (0.02-0.52) in Porphyra spp., and 0.10ppm (0.02-0.24) in Laminaria spp. in that order. If these concentrations are converted to the wet bases, they will be about 1/4 to 1/5 of the present levels. In general, the samples collected from the east coast showed relatively lower levels than those from the south coast. The mercury concentrations found in the Korean seaweeds are lower than the permissible levels reported. 3. The concentration of cadmium in the air-dried seaweeds ranged from 0.02 to 1.48 ppm, and the levels in the different species showed in the following order: 0.97 ppm (0.41-1.18) in Hizikia sp., 0.33 ppm (0.03-0.63) Undaria sp., and 0.32 ppm (0.04-0.67) in Porphyra spp. The concentration of cadmium in the samples on the wet bases become 1/4 to 1/5 of the present level. The laver Porphyra spp. collected from the east coast showed relatively lower levels than those of the cultured species along the south coast. All of the concentrations are still below than the permissible levels. 4. In general, lead concentration is 0.20-1.31 ppm which is lower than the permissible level. The concentration becomes about 0.05-0.3 ppm on the wet base. 5. Copper concentration ranged from 0.90-17.0 ppn on the dry base which is about 0.2-4.0 ppm on the wet base. It is interesting to note that the samples collected from Busan region showed relatively higher levels than those sampled from other regions.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.2
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• pp.238-245
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• 1996

Vertical profiles of $^{210}Po\;and\;^{210}Pb$ were measured for the upper 100 m of water column at six stations in the middle region of the Korean East Sea during March 1993. The distribution patterns of these radionuclides with the water mass and controlling factors on their distributions were also discussed. $^{210}Pb$ activities were generally high at surface water and gradually decrease with depth. Vertical profiles of $^{210}Po$ were relatively homogeneous except for at station E3, where chlorophyll-a concentration was the highest and $^{210}Po$ activity in the upper 30 m was lower than below 50 m. The $^{210}Po$ activities relative to its parent $^{210}Pb$ at all stations were deficient at the upper 30 m, but were excess or nearly equilibrated values below 50 m. The magnitude of $^{210}Po$ deficiency was relatively high at station E3 and E6, where strong thermocline occured. However, $^{210}Pb$ activities showed strong excess in the upper 100 m of all stations, compared with its parent $^{226}Ra$. The residence time of $^{210}Po$ ranged from 1.0 to 7.8 years, and was relatively short at station E3 and E6. The data obtained at the upper 50 m water column during $1992\~1994$, also showed that removal rate constant of $^{210}Po$ and inventories of chlorophyll-a was negatively related. This indicates that the primary production plays an important role in controlling the distributions of $^{210}Po$ at the upper water column of the Korean last Sea in spring. While, inventories of excess $^{210}Pb$ was generally decreasing with increasing density difference between 50 m and 100 m, suggesting that $^{210}Pb$ concentrations in the upper water column were controlled by stability of water column.

• Journal of Bio-Environment Control
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• v.19 no.1
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• pp.31-35
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• 2010

In this experiment, the effects on the growth and the quality of cut flowers of chrysanthemum 'Jinba' were mainly concerned depending on cultural methods between the pinching and the non-pinching. According to the results, the sufficient period of the vegetative growth was necessary to enter the flower bud differentiation in case of the non-pinching cultivation whereas it was not the case on the pinching. As compared with the pinching, the non-pinching showed 10% higher in the flowering ratio after flower bud differentiation. The flowering ratio of the non-pinching exceeded more than 95% but the pinching showed below 95% of the flowering ratio after flower bud differentiation. Comparing the number of cutting flowers between pinching and non-pinching, it was the non-pinching that showed the production of the first grade cutting flowers about 5 weeks faster than that of the pinching. It seem to be possible that harvesting time and growing period could be shortened. In the non-pinching growing region, above third-grading marketable cut flowers was 100% regardless of planting time. On the contrary, the pinching method showed 84.7% of marketable cutting flowers at first week from the planting, followed by 64.3% at second week, 18.8% at third week, and 2.6% at fourth week. Marketability of cutting flowers indicates that were planted by the pinching is very poor. When draw a comparison between the fourth-week planting of the non-pinching with the first-week planting of the pinching, the non-pinching could cut the growing period 38 days shorter than the pinching and the marketability was better. These results indicate that the non-pinching method can shorten the growing period and harvesting time compared to the pinching and it also resulted in reduction of cost and rapid production of the cutting flowers.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.23 no.4
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• pp.163-168
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• 1987

The underwater observation of the ambient noise and the noise generated by the engine revolution in a ship was carried out in July to August, 1984, 1985 and 1987, near around some ports and in the Eastern Sea of Korea. Vertical distribution of the sound pressure of both noises were observed and the spectrum characteristics were analysed and compared. The results obtained are summarized as follows: 1. Sound pressure level of the ambient noise at 5m deep layer in calm sea condition (wind speed 0-2m/s) near around the ports were observed as 108dB at the eastern part of Pusan port, 106dB at the southern part of Pusan port and 101dB at Kuryongpo port. It shows that the level near around the large port which contains much noisy resources is higher than the small port. The level at 5m deep layer in the open sea, in the mid-region between Korean Peninsula and Ulnung Island was observed as 100dB. It mean that the level in the open sea is lower than that around the ports. The level at 20m and 70m deep layer were 1-2dB lower than that at 5m deep layer, and that at deeper layer than 100m was almost constantly 100dB around. 2. Sound pressure level of the ambient noise at 5m deep layer in windy open sea condition (wind speed 10-15m/s) was 108dB, and was gradually decreased in accordance with the increase of depth with representing 100dB at 70m deep layer and that at deeper layer was almost constantly 100dB. The level of the noise generated by engine revolution was 146, 125, 112, 110, 104dB at 5, 50, 100, 150 and 200m deep layer respectively. It means that the level decrease with the depth. 3. Spectrum level of the ambient noise at 5m deep layer with the frequency band of 10 Hz, 100 Hz, 1 KHz, 10 KHz, in the windy sea condition were 86, 75, 61, 32dB respectively and the level of the noise generated by engine revolution was 105, 95, 86, 55dB respectively. It means that the latter are about 20dB higher than the former. The level of the former at 200m deep layer was 80, 68, 47, 26dB and the latter 82, 70, 59, 31dB. It means that the latter are about 4dB higher than the former.

• Journal of Life Science
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• v.15 no.3 s.70
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• pp.479-485
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• 2005

The 994 throat swabs obtained from 688 adults and 306 children patients with respiratory diseases were examined for Mycoplasma pneumoniae infection by culture method. Antimicrobial susceptibilities of the resulting 123 M. pneumoniae isolates were evaluated by testing minimum inhibitory concentrations (MICs) of erythromycin, minocycline, tetracycline, josamycin, sparfloxacin, ofloxacin, and ciprofloxacin by a broth micro-dilution method. The erythromycin resistant strains of M. pneumoniae was determined above $1.0{\mu}g/ml$ of MIC for erythromycin. The erythromycin resistant strains of M. pneumoniae was confirmed resistant gene mutation of the portions of genes 23S rRNA (domain II and V), and ribosomal protein 14 and L22 by PCR amplified and their nucleotide sequenses were compared to those of the susceptible strain M129. The isolation rate of M. pneumoniae was $12.9\%$ (89/688) for the adults and $11.1\%$ (34/306) for the children. The $MICs_{90}$ of the M. pneumoniae isolates were $0.12{\mu}g/ml$ for minocycline, $0.25{\mu}g/ml$ for sparfloxacin, $0.5{\mu}g/ml$ for ciprofloxacin, ofloxacin, and tetracycline, respectively, and $2.0{\mu}g/ml$ for josamycin and erythromycin, respectively. The isolation rate of erythromycin resistant M. pneumoniae from patients was $49.4\%\;(44/89)$ for the adults, $47.1\%\;(16/34)$ for children, and $48.8\%\;(60/123)$ for the total. No mutation could be detected in the ribosomal protein L22 region, but all strains were mutated in the ribosomal protein L4 as two point mutation M144V. Two point mutations in domain V of 23S rRNA were selected in the presense of erythromycin resistant M. pneumoniae isolates, such as one strain was G2057C mutant, two strains were A2059C mutants, three strains were C2611G mutants, four strains were A2058C mutants, five strains were A2058T mutants, twenty strains were A2059G mutants, and twenty-five strains were A2058G mutants, respectively. These results show that erythromycin was not the most active compound against M. pneumoniae infection in Korea and clinical studies of macrolides in human patients are demanded.

• Atmosphere
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• v.28 no.3
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• pp.305-315
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• 2018

This study investigates the characteristic spatial patterns and dynamic processes associated with the summertime extreme temperature events in South Korea during the last 20 years (1995~2014) using Self-Organizing Map (SOM). The classified SOM patterns commonly have high temperature and anticyclonic circulation anomalies over South Korea. The two major teleconnection patterns are identified: one is from the subtropical western North Pacific (WNP) affecting to the north and the other is from the North Atlantic (NA) affecting downstream region. The meridional teleconnection pattern is related to the forcing of positive sea surface temperature (SST) anomaly over the WNP. The northward propagating Rossby wave generates the East Asia-Pacific (EAP) pattern to form an anticyclonic circulation anomaly over South Korea. On the other hand, NA SST anomalies generate an eastward Rossby wave train across the Eurasian continent, leading to the development of an anticyclonic circulation anomaly over South Korea. The EAP pattern occurs more frequently in July and August, whereas the midlatitude teleconnection pattern associated with NA SST anomalies develops more frequently in early summer (June).