• Journal of the Korean Society of Groundwater Environment
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• v.6 no.3
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• pp.107-110
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• 1999

18 boreholes with nitrate contaminated were selected. Samples were collected 4 times between both 1995 and 1996. Stable nitrogen isotope ratio for them all was measured and the contribution to contamination from several sources like fertilizer, sewage, cropland. and landfill was analysed. Nitrogen source for 11 sampling sites of T-3, L-1. O-1∼O-4, F-2∼F-5, and G-2 considered to come from chemical fertilizer and its contribution was around 60% or more. T-4. T-5 were located downward the downtown, which were influenced bydomestic sewage and its contribution were 70.7% and 54.7%. Nitrate concentration of G-2 was 17.7 mg/L, among which 60.7% was estimated to come from landfill leachate. T-1 and T-2 were located in the small village, in which 42.2 and 43.4% of nitrogen was to come from domestic sewage but 52.8% and 56.0% were from fertilizer sprayed in the cropland. L-2 was near livestock by which it was estimated to be influenced, in which 59.9% of nitrogen was from cropland. F-1 was in the cropland, by which 50.0% was influenced and 49.5% was estimated from organic matter of animals.

• Korean Journal of Microbiology
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• v.31 no.2
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• pp.166-174
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• 1993

Streptomyces coeUc%r (Muller) cells were treated with $100 \mu$M hydrogen peroxide for I hour and proteins synthesized during hydrogen peroxide stress were labeled with L-[$^{35}S$]-methionine. Total cellular proteins were extracted and analyzed by two-dimensional polyacrylamide gel electrophoresis. In exponential growth phase, synthesis of about 100 proteins was increased by hydrogen peroxide treatment. These proteins were named as Pin (£eroxide-inducib]e) proteins and classified into 4 subgroups according to their induction time after hydrogen peroxide treatment. About 60 of them were found to be induced within 20 minutes and maintained throughout I hour of treatment. In stationary growth phase. synthesis of 62 proteins was increased by hydrogen peroxide and 21 of them were the same Pins found in exponential growth phase. Proteins from the mutants which are resistant to hydrogen peroxide were obtained in exponential growth phase and compared with those from the wild type on two-dimensional gel. The three mutants, N7, N9. and N24, were found to have higher constitutive leve]s of ]5, 17, and 15 Pin proteins respectively, than the wild type. 9 of these Pin proteins (D74.7a, E76.0c, E23.3. F50.7, F47.2a. F25.5, G39.6b, G24.0, H39.6a) increased in two of the three mutants and 3 proteins (F39.7, H6I.7. 120.8) increased in all of the three mutants. These proteins might play important roles in the response of S. coelic%r to hydrogen peroxide.

• Journal of Embryo Transfer
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• v.31 no.1
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• pp.19-25
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• 2016

This study was conducted to evaluate the effects of type of culture media (BM, G2, OS, TCM, and MEM) on B6D2F1 mice oogenesis. In the present study, B6D2F1/CrljOri $F_1$ mice were utilized in order to maximize oogenesis. Also we used TCM-199, Dulbecco's medified Eagle's medium (DMEM), embryo culture medium (Fertilization medium, Cleavage medium, Blastocyst medium), G series medium and One step medium. In vitro maturation was highest in BM followed by the order of OS, MEM, TCM and G2 ($90{\pm}2.8%>88{\pm}3.2%>85{\pm}4.9%>78{\pm}10.2%>64{\pm}7.7%$, respectively). To note, the G2 group was statistically different compared to other groups (p<0.05). On the other hand the fertilization rate was highest in the G2 group followed by BM, OS, TCM, and MEM ($87{\pm}7.2%>85{\pm}6.9%>74{\pm}14.0%>71{\pm}13.8%>2{\pm}1.4%$, respectively). The MEM group was significantly lower compared to other groups (p<0.05). The developmental rate was highest in the OS group followed by the G2 group and the BM group albeit no statistical significance was noted ($73{\pm}11.6%>71{\pm}9.2%>66{\pm}10.4%$). Of note, all cells of the TCM and MEM groups were died during embryonic development. The zona hatched rate ($51{\pm}9.8%$ vs. $50{\pm}9.1%$ vs. $47{\pm}7.2%$ for BM, G2, and OS respectively) and attached rate ($45{\pm}12.3%$ vs. $38{\pm}16.1%$ vs. $37{\pm}11.5%$ for BM, G2, and OS respectively) were not different amongst groups. No difference was found in total cell numbers ($74{\pm}13.9$ vs. $64{\pm}9.2$ vs. $76{\pm}6.7$ for BM, G2, and OS respectively), ICM cell numbers ($20{\pm}1.9$ vs. $14{\pm}1.8$ vs. $15{\pm}2.1$), TE cell numbers ($55{\pm}12.5$ vs. $49{\pm}10.7$ vs. $61{\pm}5.9$), % ICM ($30{\pm}2.8%$ vs. $24{\pm}7.0%$ vs. $22.8{\pm}2.2%$) and ICM:TE ratio ($1:2{\pm}0.5$ vs. $1:3.1{\pm}0.8$ vs. $1:3.1{\pm}0.5$) amongst groups. In summary, these results can provide fundamental data to maximize culture condition for in vitro fertilization on B6D2F1 mice.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.7
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• pp.3151-3157
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• 2013

Rib cutting is being used to many electronic components and small plastic products. In this study, comparison experiment on tool of flat type(2F) and single edge type(1F) was conducted. Results were as follows: Surface roughness and tool wear of straight cutting showed good results in tool with a straight structure of the Existing tool. Rib cutting of 7mm depth was shown 50% higher surface roughness of development tool than the existing tool. The cutting time varies depending on the shape of the rib. But it is three times faster compared to existing tool.

• Bulletin of the Korean Space Science Society
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• 2008.10a
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• pp.25.1-25.1
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• 2008

The Weddell Sea Anomaly (WSA) in the ionosphere is characterized by higher plasma density at night than during the day in the region near the Weddell Sea. According to previous studies on the WSA, it is known to occur mostly in southern summer and has not been reported in other seasons. We have utilized more than 13-year TOPEX TEC measurements in order to study how the WSA varies with seasons and how it changes with solar activity. The TOPEX TEC data have been extensively utilized for the climatological study of the ionosphere due to its excellent spatial and temporal coverage. We investigate the seasonal and solar activity variations of the WSA using four seasonal cases (Mar. equinox, Jun. solstice, Sep, equinox, and Dec. solstice) and two solar activity conditions (F10.7<120 for solar minimum and F10.7>120 for solar maximum conditions) for geomagnetically quiet periods. Our analysis shows that the WSA occurs only in the southern summer hemisphere for low F10.7, as in previous studies, but the WSA occurs all of seasons except for winter when F10.7 is high: it is most prominent during the December solstice (southern summer) and still strong during both equinoxes. The WSA appears to be an extreme case of global longitudinal variations at mid- and high-latitudes.

• Korean Journal of Crystallography
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• v.8 no.2
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• pp.132-137
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• 1997

The crystal structure of N,N'-di-tert-butoxycabonyl-2,7-diazabicyclo[3.3.0]oct-4-ene has been determined from single crystal x-ray diffraction study; C16H26N2O4, Triclinic, P1, a=11.119(1) Å, b=13.638(1) Å, c=6.214(1) Å, α=92.14(1)°, β=103.49(1)°, γ=73.35(1)°, V=877.4(2)Å3, T=293(2)K, Z=2, CuKα(λ=1.5418Å). The structure was solved by direct method and refined by full-matrix least squares to a final R=5.38% for 2389 unique observed F0>4σ(F0) reflections and 225 parameters.

• Analytical Science and Technology
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• v.14 no.2
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• pp.191-195
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• 2001

Cucurbitacin D and F, the protostane type triterpenoid of S. sorbifolia, were isolated with chromatograpic method and used as the standard substances for quantitative analysis. The compounds were identified with $^1H$-NMR, FAB-MS and UV spectrophotometer. They were separated on YMC-Pack ODS-AQ(303)[$250{\times}4.6mm$ I.D., $S-5{\mu}m$, 120A] column by HPLC. Cucurbitacin F was detected at 10.73mg/kg in cortex of S. sorbifolia, but cucurbitacin D was not. The compounds were shown to exihibit significant cytotoxicity($ED_{50}$<$0.1{\mu}g/mL$) against several tumor cell lines and acute toxicity(cucurbitacin D: 4.7mg/kg/day, cucurbitacin F: 2.5mg/kg/day) against BDF-1 mouse.

• Korean Journal of Food Science and Technology
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• v.28 no.5
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• pp.859-864
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• 1996

The rhamnan sulfat extracted from green algae seaweed, Monostroma nitidum was characterized on sugars, sulfate compositions and molecular structure. Rhamnan sulfate was extracted with boiling water, and purified with two steps of cetylpyridinium chloride and ion exchange chromatography. The yield of crude rhamnan sulfate was about 2% from raw material. Rhamnan sulfate fraction, F-4 was composed of 30% rhamnose, 0.9% arabinose, 2.5% xylose, 2% glucose and 32.6% sulfate. Rhamnan sulfate F-4-3 obtained from F-4 fraction was composed of 36.8% rhamnose, 3.6% xylose, 2.7% glucose, 1.4% galactose and 30.8% sulfate. The molecular weight of F-4-3 fraction was estimated as 10,000-10,300 dalton with Sephacryl S-200 gel filtration chromatography.

• The Plant Pathology Journal
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• v.28 no.4
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• pp.357-363
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• 2012

Several species belonging to the Gibberella fujikuroi species (Gf ) complex are commonly associated with rice and corn, not only causing serious diseases, but also producing fumonisins, a group of mycotoxins harmful to animals and humans. To characterize the population structure of the putative fumonisin-producing Gf complex in Korea, we obtained 276 candidate isolates from rice and corn harvested in 2009 and 2010 by diagnostic polymerase chain reaction with several specific primer sets. Phylogenetic trees were constructed using multilocus sequences (combined RPB2 and EF1A, totaling 1.6 kb) from these isolates. Among the 135 isolates from rice, F. fujikuroi (teleomorph: G. fujikuroi; 59.3%) and F. proliferatum (G. intermedia; 13.3%) were predominant, followed by F. concentricum (5.9%). Additionally, twenty-five (18.5%) rice isolates belonged in a distinct subclade of F. commune, a non-member of the Gf complex. In contrast, F. verticillioides was the most predominant species (38.3%) among the 141 corn isolates, and followed by F. fujikuroi (27.7%), F. proliferatum (14.9%), F. subglutinans (7.1%), and F. concentricum (2.8%). A single mating type (MAT1-1) was found predominantly among the Gf complex isolates examined. Possible distinct subclades were detected within the populations of F. fujikuroi and F. proliferatum; however, this needs further confirmation. This is the first reported population-level characterization of putative fumonisin-producing Gf complex associated with rice and corn in Korea.

• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.2
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• pp.36-40
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• 2011

Purpose: $^{18}F$-FDG injected dose to the patient is quite different between the recommended dose from manufacturer and the actual dose applied to each of hospitals. injection of inappropriate $^{18}F$-FDG dose may not only increase the exposed dose to patients but also reduce the image quality. we thus evaluated the proper $^{18}F$-FDG injected dose to decrease the exposed dose to patients considering the image quality. Materials And Methods: NEMA Nu2-1994 phantom was filled with $^{18}F$-FDG increasing hot cylinder radioactivity concentration to 1, 3, 5, 7, 9 MBq/kg based on the ratio of 4:1 between the hot cylinder and background activity. after completing the transmission scan using ct, emission scan was acquired in 3D mode for 2 minutes 30 seconds/bed. ROI was set up on hot cylinder and background radioactivity region. after measuring $SUV_{max}$ those regions, then analyzed SNR at the points. clinical experiment has been conducted the object of patients who have came to smc from november 2009 to august 2010, 97 patients without having a hepatic lesions were selected. ROI was set up in the liver and thigh area. after measuring $SUV_{max}$, the image quality was compared following the injected dose. Results: in phantom study, as the injected radioactivity concentration per unit mass was 1, 3, 5, 7, 9 MBq/kg, $SUV_{max}$ was 23.1, 24.1, 24.3, 22.8, 23.6 and SNR was shown 0.48, 0.54, 0.56, 0.55, 0.55. according to increment of the injected dose, $SUV_{max}$ and SNR was increased under 5 MBq/kg but they were decreased over 7 MBq/kg. in case of clinical experiment, as increased the injected radioactivity concentration per unit mass was 4.72, 5.34, 6.16, 7.41, 8.68 MBq/kg, $SUV_{max}$ was 2.68, 2.67, 2.26, 1.88, 1.95 and SNR was shown 0.52, 0.53, 0.46, 0.46, 0.44. if the injected dose exceeds 5 MBq/kg, showed a decrease pattern as phantom study. Conclusion: increasing $^{18}F$-FDG injected dose considered patient's body weight improve image quality within a certain range. if it exceeds the range, it can be reduced image quality due to random and scatter coincidences. this study indicates that the optimal injected dose was 5 MBq/kg per unit mass the injected radioactivity concentration in 3d wb pet/ct.