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Detection of Matrix Metalloproteinases Patterns in Bovine Luteum cell during Pregnancy
Sang-Hwan Kim,Kyong-Lae Kim,Ji-Hye Lee,Da-Hye Shin,Na-Hyeon Jung,Ho-Jun Lee,Jong-Taek Yoon 한국수정란이식학회 2018 한국동물생명공학회지 Vol.33 No.2
The major focus of this study is to analyze the expression of bovine MMPs and to monitor their activity during the estrus cycle and pregnancy. During pregnancy, MMP-2 expression was detectable around 30 days but became insignificant by 60 days, then started to increase again around 90 days and reached the maximum at 250 days. The activity of MMP-2 protein changed in accordance with its expression level. As expected, the level of TIMP-2 exhibited a reverse pattern. About MMP-9, high level expression was observed as early as 30 days and gradually increase until 90 days. Then started to decrease after 250 days. Again, the sites of MMP-9 expression were similar to those of MMP-2. On the other hand, expression of TIMP-3 remained low until 90 days but showed a small and temporal increase around 250 days. In summary, expression of different MMPs were differentially regulated during estrus cycle and pregnancy. While the expression of MMP-2 was high in estrus cycle, MMP-9 slowly takes over with the progression of pregnancy. These results indicated that the luteal tissue perform distinct functions during pregnancy and estrus. Perhaps the activity of MMP-2 is required for the structural remodeling of luteum, resulting the suppression of P4 inflow from blood. On the other hand, steady maintenance of MMP-9 throughout luteal development is important for the activation of cell proliferation, maturation and angiogenesis.
Lee, Hui-Soon,Park, Kyung-Lae,Choi, Sang-Un,Lee, Chong-Ock,Jung, Sang-Hun The Pharmaceutical Society of Korea 2000 Archives of Pharmacal Research Vol.23 No.6
To explore the effect of substituents' on phenyl motif on sulfonyl function of novel anticancer 4-phenyl-1-benzenesulfonylimidazolidinones (1), electron donating or withdrawing sub-stituents were introduced at 3 or 4-position and the analogs were tested against human lung (A549) and colon (HCT-15) cancer cell lines. Quantitative structure activity relation-ship of the 4-substituted series shows that only STERIMOL L values are well correlated. The increment of substituent's volume enhances the activity against both cell lines. The small substituent at 3-position additionally increases the activity. However naphthyl group in place of phenyl reduces the activity, Therefore the phenyl motif with sterically large substituent at 4-position and small substituent at 3-position may be important for their activity. Integration of these substituents' effects into the structural design led to discover the more potent analog, 4-phenyl-1-(N-acetylindoline-5-sulfonyl) imidazolidinone (1n).
Tribological Improvement of Lubricants Using Silicone Rubber Powders in Hydrogen Compressors
Sung-Jun Lee(이성준),Chang-Lae Kim(김창래) 한국트라이볼로지학회 2024 한국트라이볼로지학회지 (Tribol. Lubr.) Vol.40 No.3
The development of eco-friendly alternative energy sources has become a global priority owing to the depletion of fossil fuels and an increase in environmental concerns. Hydrogen energy has emerged as a promising clean energy source, and hydrogen compressors play a crucial role in the storage and distribution of compressed hydrogen. However, harsh operating conditions lead to the rapid deterioration of conventional lubricants in hydrogen compressors, thereby necessitating the development of advanced lubrication technologies. This study introduces micrometer-sized silicone rubber powders as lubricant additives to enhance the lubrication performance of hydraulic oils in hydrogen compressors. We prepare silicone rubber powders by varying the ratio of the silicone rubber base to the curing agent and investigate their effects on interfacial properties, friction behavior, and wear characteristics. The findings reveal that the incorporation of silicone rubber powders positively influences the surface affinity, wettability, friction reduction, and wear resistance of the lubricants on the 304SS substrate. Moreover, we identify the optimal lubricant formulations, with a 15:1 ratio demonstrating the most effective friction reduction and a 5:1 ratio exhibiting the highest wear resistance. The controlled surface modification by the silicone rubber powder and the enhanced interfacial characteristics of the powder-containing lubricants synergistically contribute to the improved lubrication performance. These results indicate the potential of silicone rubber powder additives for the development of long-life lubrication solutions for hydrogen compressors and related applications, ultimately contributing to the advancement of sustainable energy technologies.
Lee Jae Woong,Won Yu-Jung,Kang Lae Hyung,Lee Sung-Geun,Park Seung-Won,Paik Soon-Young 한국미생물학회 2020 The journal of microbiology Vol.58 No.8
Severe fever with thrombocytopenia syndrome (SFTS) is being reported annually in South Korea since its first detection there in 2010. The causal agent is a negative-strand RNA virus 80–100 nm in diameter. It causes fever, thrombocytopenia, leukocytopenia, gastrointestinal symptoms, and neural symptoms. The mortality rate of SFTS was 32.6% among 172 cases reported from 2012 to 2015 in South Korea. Thus, is necessary to develop an effective diagnostic method that selectively identifies the isolates circulating in South Korea. The real-time reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay is a simple, rapid, and sensitive approach for molecular diagnosis. Here, we designed novel primers for this assay and found that the technique had very high specificity, sensitivity, and efficiency. This real-time RTLAMP approach using the novel primers developed herein can be applied for early diagnosis of SFTSV strains in South Korea to reduce the mortality rate of SFTS.
Lee, Yang-Seok,Jeong, Dong-Hoon,Lee, Dong-Yeon,Yi, Jakyung,Ryu, Choong-Hwan,Kim, Song L.,Jeong, Hee J.,Choi, Sang C.,Jin, Ping,Yang, Jungil,Cho, Lae-Hyeon,Choi, Heebak,An, Gynheung Blackwell Publishing Ltd 2010 The Plant journal Vol.63 No.1
<P>Summary</P><P>Plants recognize environmental factors to determine flowering time. <I>CONSTANS</I> (<I>CO</I>) plays a central role in the photoperiod flowering pathway of Arabidopsis, and CO protein stability is modulated by photoreceptors. In rice, <I>Hd1</I>, an ortholog of <I>CO</I>, acts as a flowering promoter, and phytochromes repress <I>Hd1</I> expression. Here, we investigated the functioning of <I>OsCOL4</I>, a member of the <I>CONSTANS-like</I> (<I>COL</I>) family in rice. <I>OsCOL4</I> null mutants flowered early under short or long days. In contrast, <I>OsCOL4</I> activation-tagging mutants (<I>OsCOL4-D</I>) flowered late in either environment. Transcripts of <I>Ehd1</I>, <I>Hd3a</I>, and <I>RFT1</I> were increased in the <I>oscol4</I> mutants, but reduced in the <I>OsCOL4-D</I> mutants. This finding indicates that <I>OsCOL4</I> is a constitutive repressor functioning upstream of <I>Ehd1.</I> By comparison, levels of <I>Hd1</I>, <I>OsID1</I>, <I>OsMADS50</I>, <I>OsMADS51</I>, and <I>OsMADS56</I> transcripts were not significantly changed in <I>oscol4</I> or <I>OsCOL4-D</I>, suggesting that <I>OsCOL4</I> functions independently from previously reported flowering pathways. In <I>osphyB</I> mutants, <I>OsCOL4</I> expression was decreased and <I>osphyB oscol4</I> double mutants flowered at the same time as the <I>osphyB</I> single mutants, indicating <I>OsCOL4</I> functions downstream of <I>OsphyB.</I> We also present evidence for two independent pathways through which OsPhyB controls flowering time. These pathways are: (i) night break-sensitive, which does not need <I>OsCOL4</I>; and (ii) night break-insensitive, in which <I>OsCOL4</I> functions between <I>OsphyB</I> and <I>Ehd1.</I></P>
Observation of the Ring-Puckering Vibrational Mode in Thietane Cation
Lee, Yu Ran,Park, Chung Bin,Hwang, Jiye,Sung, Bong June,Kim, Hong Lae,Kwon, Chan Ho American Chemical Society 2017 The Journal of physical chemistry A Vol.121 No.5
<P>We have measured the high-resolution vibrational spectra of a thietane (trimethylene sulfide) cation in the gas phase by employing the vacuum ultraviolet mass analyzed threshold ionization (VUV-MATI) spectroscopic technique. Peaks in the low frequency region of the observed MATI spectrum of thietane originate from a progression of the ring-puckering vibrational mode (typical in small heterocyclic molecules), which is successfully reproduced by quantum-chemical calculations with 1D symmetric double-well potentials along the ring puckering coordinates on both the S-0 and D-0 states, the ground electronic states of neutral and cation of thietane, respectively. The values of the interconversion barrier and the ring-puckering angle on the S-0 state, the parameters used for the quantum-chemical calculations, were assumed to be 274 cm(-1) and 26 degrees. The barrier and the angle on the D-0 state, however, are found to be 48.0 cm(-1) and 18.2 degrees, respectively, where such small barrier height and puckering angle for the cation suggest that the conformation of thietane cation on the D-0 state should be more planar-than that of the thietane neutral.</P>
Sang-Lae Lee,Ji-Hwan Kim 대한기계학회 2007 대한기계학회 춘추학술대회 Vol.2007 No.5
In this study, it is investigated the thermal post-buckling characteristics of step-formed FG panel under the heat and supersonic flow. Material properties are assumed to be temperature dependent as well as continuously varying in the thickness direction of the panel according to a simple power law distribution in terms of the volume fraction of the constituent. First-order shear deformation theory(FSDT) of plate is applied to model the panel, and the von Karman strain-displacement relations are adopted to consider the geometric nonlinearity due to large deformation. Also, the first-order piston theory is used to model the supersonic aerodynamic load acting on a panel. Numerical results are summarized to reveal the thermal post-buckling behaviors of FG panels with various volume fractions, temperature conditions and aerodynamic pressures in detail.