• Animal cells and systems
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• 제4권2호
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• pp.117-121
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• 2000

Genetic relationships among six species of the genus Rana from Korea were investigated by complete nucleotide sequence analyses of mitochondrial cytochrome b gene (1143 bp). Based on Kimura-2-parameter distance, the interspecific sequence differences of cytochrome b gene within the genus Rana were ranged from 7.83% to 25.00%. The genetic distances were 7.83% between R. nigromaculata and R. plancyi, 8.47% between two types of R. rugosa (type A and B), 10.42% between the brown frogs (R. amurensis and R. dybowskii), 16.11% between R. dybowskii types 1 and 2 and 12.36% between pond frogs (R. nigromaculata and R. plancyi) and R. catesbeiana. In the neighbor-joining and parsimony trees, R. catesbeiana was more closely related to pond frogs than brown frogs. R. dybowskii types 1 and 2 were considered to be at a distinct and specific level of differentiation (16.11%), while two types of R. rugosa were suspected to be at a subspecific level (8.47%).

• Bulletin of the Korean Chemical Society
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• 제28권11호
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• pp.2009-2014
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• 2007

The aminolysis of diphenyl thiophosphinic chloride (2) with substituted anilines in acetonitrile at 55.0 oC is investigated kinetically. Kinetic results yield large Hammett ρX (ρnuc = ?3.97) and Bronsted βX (βnuc = 1.40) values. A concerted mechanism involving a partial frontside nucleophilic attack through a hydrogen-bonded, four-center type transition state is proposed on the basis of the primary normal kinetic isotope effects (kH/kD = 1.0-1.1) with deuterated aniline (XC6H4ND2) nucleophiles. The natural bond order charges on P and the degrees of distortion of 42 compounds: chlorophosphates [(R1O)(R2O)P(=O)Cl], chlorothiophosphates [(R1O)(R2O)P(=S)Cl], phosphonochloridates [(R1O)R2P(=O)Cl], phosphonochlorothioates [(R1O)R2P(=S)Cl], chlorophosphinates [R1R2P(=O)Cl], and chlorothiophosphinates [R1R2P(=S)Cl] are calculated at the B3LYP/ 6-311+G(d,p) level in the gas phase.

• 한국융합학회논문지
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• 제11권9호
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• pp.433-441
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• 2020

본 연구는 온라인 수업에 참여한 간호대학생의 딴짓에 영향을 미치는 요인을 파악하기 위해 수행하였다. 자료수집은 3개 대학에 재학 중인 간호대학생 304명을 대상으로 2020년 4월 20일부터 4월 30일까지 구조화된 자가 보고식 설문지 작성을 통해 수집하였다. 자료 분석은 SPSS 26.0 program을 이용하여 T-test, ANOVA, Pearson's correlation coefficient, multiple regression을 이용하였다. 연구결과, 딴짓은 흥미도(r=-17, p=.003), 이해도(r=-19, p=.001), 필요도(r=-12, p=.031), 학습동기(r=-12, p=.046), 자기조절효능감(r=-11, p=.040), 학습자신감(r=-14, p=.017), 강의만족도(r=-22, p<.001), 강의몰입(r=-24, p<.001)과 유의한 상관관계를 보였다. 또한 학습자신감(β= -.20), 토론 및 발표선호정도(β= .19), 강의몰입(β= -.15), 강의만족도(β= -.15)이 딴짓에 유의한 영향을 미치는 것으로 확인되었으며(F=9.95, p<.001), 모형의 설명력은 10.6%였다. 본 연구를 통해 온라인 수업에 있어 간호대학생의 딴짓을 감소시키기 위한 교수학습방법 및 프로그램의 개발을 제언한다.

• 환경생물
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• 제26권2호
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• pp.87-93
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• 2008

낙동강 상류로부터 유입되는 각종 오염물질로 심하게 오염된 낙동강 하구역에서 오염정도가 다른 두 지역으로부터 문절망둑 Acanthogobius flavimanus을 채집하여 이들의 간중량지수(HSI), 생식선중량지수(GSI), 해독효소계 및 성 호르몬 수준을 비교하였다. 해독효소계로는 cytochrome P450 (CYP), NADPH-cytochrome P450 reductase (P450R), NADH-cytochrome b5 reductase (b5R), ethokyresorufin deethylase (EROD), glutathione S-transferase (GST)를 조사하였고, 성 호르몬으로는 자성호르몬인 17$\beta$-estradio(E2)을 비롯하여 웅성호르몬인 testosterone (TT), 11-ketotestolterone (11-KT)을 측정하였다. 그 결과, HSI는 site 1에서 잡은 것이 암수 모두 유의적으로 컸고, GSI는 site 1의 암컷에서 유의적으로 작았다. 그리고 성호르몬 중 11-KT과 TT농도는 오염지역에 따라 차이를 보이지 않았지만, E2농도는 site 1에서 유의적으로 높았다(p<0.05).그리고 해독효소계의 수준은 site 1의 것이 CYP와 EROD수준은 유의적으로 낮았던 반면에 P450R, b5R 및 GST 활성은 site 1에서 높았다. 이들 결과를 정리하면, 낙동강 하구에 서식하는 문절망둑은 성 호르몬 대사를 교란시키는 화합물에 의해 영향을 받고 있으며, 특히 암컷이 더욱 크게 받는다는 것을 확인할 수 있었다.

• Journal of Ginseng Research
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• 제46권6호
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• pp.738-749
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• 2022

Background: Ginseng possesses antitumor effects, and ginsenosides are considered to be one of its main active chemical components. Ginsenosides can further be hydrolyzed to generate secondary saponins, and 20(R)-panaxotriol is an important sapogenin of ginsenosides. We aimed to synthesize a new ginsengenin derivative from 20(R)-panaxotriol and investigate its antitumor activity in vivo and in vitro. Methods: Here, 20(R)-panaxotriol was selected as a precursor and was modified into its derivatives. The new products were characterized by ¹H-NMR, ¹³C-NMR and HR-MS and evaluated by molecular docking, MTT, luciferase reporter assay, western blotting, immunofluorescent staining, colony formation assay, EdU labeling and immunofluorescence, apoptosis assay, cells migration assay, transwell assay and in vivo antitumor activity assay. Results: The derivative with the best antitumor activity was identified as 6,12-dihydroxy-4,4,8,10,14-pentamethyl-17-(2,6,6-trimethyltetrahydro-2H-pyran-2-yl)hexadecahydro-1H-cyclopenta[a]phenanthren-3-yl(tert-butoxycarbonyl)glycinate (A11). The focus of this research was on the antitumor activity of the derivatives. The efficacy of the derivative A11 (IC₅₀ < 0.3 µM) was more than 100 times higher than that of 20(R)- panaxotriol (IC₅₀ > 30 µM). In addition, A11 inhibited the protein expression and nuclear accumulation of the hypoxia-inducible factor HIF-1α in HeLa cells under hypoxic conditions in a dose-dependent manner. Moreover, A11 dose-dependently inhibited the proliferation, migration, and invasion of HeLa cells, while promoting their apoptosis. Notably, the inhibition by A11 was more significant than that by 20(R)-panaxotriol (p < 0.01) in vivo. Conclusion: To our knowledge, this is the first study to report the production of derivative A11 from 20(R)-panaxotriol and its superior antitumor activity compared to its precursor. Moreover, derivative A11 can be used to further study and develop novel antitumor drugs.

• Animal Bioscience
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• 제37권3호
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• pp.509-521
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• 2024

Objective: It was shown that microRNAs (miRNAs) play an important role in milk protein synthesis. However, the post-transcriptional regulation of casein expression by exogenous miRNA (xeno-miRNAs) in ruminants remains unclear. This study explores the regulatory roles of alfalfa xeno-miR162 on casein synthesis in bovine mammary epithelial cells (bMECs). Methods: The effects of alfalfa xenomiR-162 and G protein subunit gamma 11 (GNG11) on proliferation and milk protein metabolism of bMECs were detected by 5-Ethynyl-2'-Deoxyuridine (EdU) staining, flow cytometry, cell counting kit-8 (CCK-8), enzyme-linked immunosorbent assay, quantitative real-time polymerase chain reaction (qRT-PCR), and Western blot. Dual-luciferase reporter assay was used to verify the targeting relationship between GNG11 and xenomiR-162. Results: Results showed that over-expression of xenomiR-162 inhibited cell proliferation but promoted apoptosis, which also up-regulated the expression of several casein coding genes, including CSN1S1, CSN1S2, and CSN3, while decreasing the expression of CSN2. Furthermore, the targeting relationship between GNG11 and xenomiR-162 was determined, and it was confirmed that GNG11 silencing also inhibited cell proliferation but promoted apoptosis and reduced the expression of casein coding genes and genes related to the mammalian target of rapamycin (mTOR) pathway. Conclusion: Alfalfa xenomiR-162 appears to regulate bMECs proliferation and milk protein synthesis via GNG11 in the mTOR pathway, suggesting that this xeno-miRNA could be harnessed to modulate CSN3 expression in dairy cows, and increase κ-casein contents in milk.

• 대한기계학회논문집B
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• 제24권9호
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• pp.1239-1246
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• 2000

The objective of this work is to measure space and time resolved wall heat fluxes during nucleate pool boiling of R113/R11 mixtures using a microscale heater array in conjunction with a high speed CCD. The microscale heater array is constructed using VLSI techniques, and consists of 96 serpentine platinum resistance heaters on a transparent quartz substrate. Electronic feedback circuits are used to keep the temperature of each heater at a specified temperature and the variation in heating power required to keep the temperature constant is measured. Heat flux data around an isolated bubble are obtained with triggered CCD images. CCD images are obtained at a rate of 1000frames/second. The heat transfer variation vs. time on the heaters directly around the nucleation site is plotted and correlated with images of the bubble obtainedby using the high speed CCD. For both of the mixture(R11/R113) and pure system(pure R11, pure R113), the wall heat fluxes are presented and compared to find out the qualitative difference between pure and binary mixture nucleate boiling.

• Current Research on Agriculture and Life Sciences
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• 제10권
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• pp.49-52
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• 1992

혐기성(嫌氣性) 광합성(光合成) 세균(細菌)인 R. capsulata B22와 R. spheroides SM11의Bio-fertilizer로의 이용(利用) 가능성(可能性)을 조사(調査)하였다. R. capsulata B22와 R. spheroides SM11을 각각 토양(土壤)에 처리(處理)하여 토양(土壤)의 유기물(有機物) 함량(含量)과 질소(窒素) 함량(含量)의 변화(變化)를 조사(調査)한 결과(結果), 배양(培養) 5일(日) 후(後)부터 모든 처리구(處理區)에서 Algae의 번식(繁殖)이 관찰(觀察)되었으며 15-20일(日)까지 약간(若干)의 유기물(有機物) 및 질소함량(窒素含量)의 증가(增加)가 관찰(觀察)되었다.

• 환경위생공학
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• 제14권4호
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• pp.143-149
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• 1999

In the tungsten industry as light source material, tungsten filament which used as light source material could form after molybdenumwire which used as the center supporter for coil shape tungsten wire was removed. This process uses hydrogen peroxide, Ozone and UV(Ultraviolet)Lamp, for the quantity of hydrogen peroxide decrease. The results were as follows : 1. An incandescent electric Lamp type : FL(FL-20) type : A standard of commodity (P.W.: $19{\pm}1.0mg$, $C.R:4.5{\pm}0.3{\Omega}$) 1) Only hydrogen peroxide treated ; Reaction Time : 65Min., P.W.: 18.60mg, $C.R.:4.60{\Omega}$ 2) Ozone/Ultraviolet/70% of hydrogen peroxide; Reaction Time : 64Min., P.W.: 18.61mg, C.R.: $4.61{\Omega}$ 2. A Fluorescent Lamp Type : GLS(GLS-40) Type : A standard of commodity(P.W.: $11.8{\pm}0.2mg$$65{\pm}1.5{\Omega}$) 1) Only hydrogen peroxide treated ; Reaction Time: 72Min, P.W.:11.88mg, C.R.: $65.62\Omega$ 2) Ozone/Ultraviolet/70% of hydrogen peroxide;Reaction Time:71Min., P.W.:11.88mg, C.R.: $65.63\Omega$

• 설비공학논문집
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• 제10권3호
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• pp.303-314
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• 1998

In this study, the performance of a multi-stage condensation heat pump was examined. Computer simulation programs were developed for 1-stage, 2-stage, and 3-stage heat pumps and R11, R123, R141b were tested as working fluids. The results showed that coefficients of performance(COPs) of an optimized 3-stage condensation heat pump are 25∼40% higher than those of a conventional 1-stage heat pump. The increase in COP, however, differed among the fluids tested. The improvement in COP largely stems from the decrease in average LMTD values in the condensers of the multi-stage system. For the 3-stage condensation heat pumps, optimized UA values of three condensers were determined to be 30∼40% of the UA value of the total condenser regardless of the working fluid. When the amount of cooling water entering into the intermediate and high-stage subcoolers is roughly 10% of the total condenser cooling water respectively, the optimum performance was achieved for the 3-stage condensation heat pump.