• Title/Summary/Keyword: ${\pi}?{\pi}$ interaction

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The MO Study about Interaction of cis-Diamminedichloroplatinum (cis-DDP) Complexes with DNA base, 1-Methylcytosine, for Development of Anti-Tumor Drugs (항암성물질의 개발을 위한 cis-Diamminedichloroplatinum (cis-DDP) 류와 DNA base인 1-Methylcytosine의 Interaction에 관한 분자궤도함수론적 연구)

  • Kim, Ui Rak;Kim, Sang Hae;Edward A. Boudreaux
    • Journal of the Korean Chemical Society
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    • v.34 no.4
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    • pp.331-339
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    • 1990
  • It has been studied that relations between electronic structure and anti-tumor activity by variation of amine group in cis-diamminedichloroplatinum (Ⅱ) complexes. We were also interested in these Pt (Ⅱ) complexes interaction with 1-methylcytosine of DNA base and the electronic structure of these complexes in order to understand the mechanism of the metal-nucleobases interaction. The results showed that net charge of center metal in Pt complexes effect anti-tumor activity. The mechanisgm of the bonding between metal and ligands largely based on charge transfer from ligand to metal atom. Furthermore, the established molecular orbitals showed that metal 6p-orbitals played an important role in the bonding scheme for the interactions between platinum (Ⅱ) complexes and 1-methylcytosine. We also found that the stronger Pt-N3 bonding strength became, the better anti-tumor agents were.

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Low-cost system design to collect interaction information during conversation (저비용 대화 상호작용 정보 수집 시스템 설계)

  • Sangjin, Cho;Jaehyun, Park;Woonki, Hong
    • Journal of Korea Society of Industrial Information Systems
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    • v.28 no.1
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    • pp.9-16
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    • 2023
  • The importance of team activities increases as the problem to be solved in the industrial field become more diverse and complex. Team performance is not simply the sum of team members' performances, but synergies are gained or reduced depending on the team's interactions. Analytical research on team activities using ICT has been conducted, but developing and utilizing these technologies is time-consuming and costly, making it difficult for field practitioners and researchers to utilize them. In this study, we design a system that collects interaction information during conversations at a low cost using Arduino and Raspberry Pi and verify that conversation interaction information is collected from multiple devices and correctly stored in the database. Through the low-cost information collection system proposed in this study, we intend to create an environment where follow-up research can be conducted in various fields of industrial information.

Improvement of the Beam-Wave Interaction Efficiency Based on the Coupling-Slot Configuration in an Extended Interaction Oscillator

  • Zhu, Sairong;Yin, Yong;Bi, Liangjie;Chang, Zhiwei;Xu, Che;Zeng, Fanbo;Peng, Ruibin;Zhou, Wen;Wang, Bin;Li, Hailong;Meng, Lin
    • Journal of the Korean Physical Society
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    • v.73 no.9
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    • pp.1362-1369
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    • 2018
  • A method aimed at improving the beam-wave interaction efficiency by changing the coupling slot configuration has been proposed in the study of extended interaction oscillators (EIOs). The dispersion characteristics, coupling coefficient and interaction impedance of the high-frequency structure based on different types of coupling slots have been investigated. Four types of coupled cavity structures with different layouts of the coupling slots have been compared to improve the beam-wave interaction efficiency, so as to analyze the beam-wave interaction and practical applications. In order to determine the improvement of the coupling slot to a coupled cavity circuit in an EIO, we designed four nine-gap EIOs based on the coupled cavity structure with different coupling slot configurations. With different operating frequencies and voltages takes into consideration, beam voltages from 27 to 33 kV have been simulated to achieve the best beam-wave interaction efficiency so that the EIOs are able to work in the $2{\pi}$ mode. The influence of the Rb and the ds on the output power is also taken into consideration. The Rb is the radius of the electron beam, and the ds is the width of the coupling slot. The simulation results indicate that a single-slot-type EIO has the best beam-wave interaction efficiency. Its maximum output power is 2.8 kW and the efficiency is 18% when the operating voltage is 31 kV and electric current is 0.5 A. The output powers of these four EIOs that were designed for comparison are not less than 1.7 kW. The improved coupling-slot configurations enables the extended interaction oscillator to meet the different engineering requirements better.

Protein-protein Interaction Network Analyses for Elucidating the Roles of LOXL2-delta72 in Esophageal Squamous Cell Carcinoma

  • Wu, Bing-Li;Zou, Hai-Ying;Lv, Guo-Qing;Du, Ze-Peng;Wu, Jian-Yi;Zhang, Pi-Xian;Xu, Li-Yan;Li, En-Min
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.5
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    • pp.2345-2351
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    • 2014
  • Lysyl oxidase-like 2 (LOXL2), a member of the lysyl oxidase (LOX) family, is a copper-dependent enzyme that catalyzes oxidative deamination of lysine residues on protein substrates. LOXL2 was found to be overexpressed in esophageal squamous cell carcinoma (ESCC) in our previous research. We later identified a LOXL2 splicing variant LOXL2-delta72 and we overexpressed LOXL2-delta72 and its wild type counterpart in ESCC cells following microarray analyses. First, the differentially expressed genes (DEGs) of LOXL2 and LOXL2-delta72 compared to empty plasmid were applied to generate protein-protein interaction (PPI) sub-networks. Comparison of these two sub-networks showed hundreds of different proteins. To reveal the potential specific roles of LOXL2- delta72 compared to its wild type, the DEGs of LOXL2-delta72 vs LOXL2 were also applied to construct a PPI sub-network which was annotated by Gene Ontology. The functional annotation map indicated the third PPI sub-network involved hundreds of GO terms, such as "cell cycle arrest", "G1/S transition of mitotic cell cycle", "interphase", "cell-matrix adhesion" and "cell-substrate adhesion", as well as significant "immunity" related terms, such as "innate immune response", "regulation of defense response" and "Toll signaling pathway". These results provide important clues for experimental identification of the specific biological roles and molecular mechanisms of LOXL2-delta72. This study also provided a work flow to test the different roles of a splicing variant with high-throughput data.

Class A and class B MADS box genes fro rice flower development

  • An, Gyn-Heung;Moo,Yong-Hwan;Jeon, Jong-Seong;Kang, Hong-Gyu;Sung, Soon-Kee
    • Proceedings of the Botanical Society of Korea Conference
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    • 1999.07a
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    • pp.21-35
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    • 1999
  • We have previously isolated OsMADS4 gene that is a member of the class B MADS box genes from rice. In this study, another member of the class B MADS box genes was isolated from rice flower by the yeast two-hybrid screening method using OsMADS4 as bait. RNA blot analyses revealed that the clone, OsMADS16, was expressed in the second and third whorls, whereas the OsMADS4 transcripts were present in the second, third, and fourth whorls. These expression patterns of the OsMADS16 and OsMADS4 genes are very similar with those of AP3 and PI, the class B genes of Arabidopsis, respectively. In the yeast two-hybrid system, OsMADS4 interacted only with OsMADS16 among several rice MADS genes investigated, suggesting that OsMADS4 and OsMADS16 function as a heterodimer in specifying sepal and petal identities. We have also isolated OsMADS6 gene using OsMADS1 as a probe. Both are members of the AGL2 MADS family. Various MADS genes that encode for protein-protein interaction partners of the OsMADS6 protein were isolated by the yeast two-hybrid screening method. A majority of these genes belong to the AGL2 family. Sequence Homology, expression pattern, and ectopic expression phenotypes indicated that one of the interaction partners, OsMADS14, appears to be homologous to API, the class A MADS gene of Arabidopsis.

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Stage specific transcriptome profiles at cardiac lineage commitment during cardiomyocyte differentiation from mouse and human pluripotent stem cells

  • Cho, Sung Woo;Kim, Hyoung Kyu;Sung, Ji Hee;Han, Jin
    • BMB Reports
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    • v.54 no.9
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    • pp.464-469
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    • 2021
  • Cardiomyocyte differentiation occurs through complex and finely regulated processes including cardiac lineage commitment and maturation from pluripotent stem cells (PSCs). To gain some insight into the genome-wide characteristics of cardiac lineage commitment, we performed transcriptome analysis on both mouse embryonic stem cells (mESCs) and human induced PSCs (hiPSCs) at specific stages of cardiomyocyte differentiation. Specifically, the gene expression profiles and the protein-protein interaction networks of the mESC-derived platelet-derived growth factor receptor-alpha (PDGFRα)+ cardiac lineage-committed cells (CLCs) and hiPSC-derived kinase insert domain receptor (KDR)+ and PDGFRα+ cardiac progenitor cells (CPCs) at cardiac lineage commitment were compared with those of mesodermal cells and differentiated cardiomyocytes. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses revealed that the genes significantly upregulated at cardiac lineage commitment were associated with responses to organic substances and external stimuli, extracellular and myocardial contractile components, receptor binding, gated channel activity, PI3K-AKT signaling, and cardiac hypertrophy and dilation pathways. Protein-protein interaction network analysis revealed that the expression levels of genes that regulate cardiac maturation, heart contraction, and calcium handling showed a consistent increase during cardiac differentiation; however, the expression levels of genes that regulate cell differentiation and multicellular organism development decreased at the cardiac maturation stage following lineage commitment. Additionally, we identified for the first time the protein-protein interaction network connecting cardiac development, the immune system, and metabolism during cardiac lineage commitment in both mESC-derived PDGFRα+ CLCs and hiPSC-derived KDR+PDGFRα+ CPCs. These findings shed light on the regulation of cardiac lineage commitment and the pathogenesis of cardiometabolic diseases.

Chlorogenic acid alleviates the reduction of Akt and Bad phosphorylation and of phospho-Bad and 14-3-3 binding in an animal model of stroke

  • Murad-Ali, Shah;Ju-Bin, Kang;Myeong-Ok, Kim;Phil-Ok, Koh
    • Journal of Veterinary Science
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    • v.23 no.6
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    • pp.84.1-84.15
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    • 2022
  • Background: Stroke is caused by disruption of blood supply and results in permanent disabilities as well as death. Chlorogenic acid is a phenolic compound found in various fruits and coffee and exerts antioxidant, anti-inflammatory, and anti-apoptotic effects. Objectives: The purpose of this study was to investigate whether chlorogenic acid regulates the PI3K-Akt-Bad signaling pathway in middle cerebral artery occlusion (MCAO)-induced damage. Methods: Chlorogenic acid (30 mg/kg) or vehicle was administered peritoneally to adult male rats 2 h after MCAO surgery, and animals were sacrificed 24 h after MCAO surgery. Neurobehavioral tests were performed, and brain tissues were isolated. The cerebral cortex was collected for Western blot and immunoprecipitation analyses. Results: MCAO damage caused severe neurobehavioral disorders and chlorogenic acid improved the neurological disorders. Chlorogenic acid alleviated the MCAO-induced histopathological changes and decreased the number of terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells. Furthermore, MCAO-induced damage reduced the expression of phospho-PDK1, phospho-Akt, and phospho-Bad, which was alleviated with administration of chlorogenic acid. The interaction between phospho-Bad and 14-3-3 levels was reduced in MCAO animals, which was attenuated by chlorogenic acid treatment. In addition, chlorogenic acid alleviated the increase of cytochrome c and caspase-3 expression caused by MCAO damage. Conclusions: The results of the present study showed that chlorogenic acid activates phospho-Akt and phospho-Bad and promotes the interaction between phospho-Bad and 14-3-3 during MCAO damage. In conclusion, chlorogenic acid exerts neuroprotective effects by activating the Akt-Bad signaling pathway and maintaining the interaction between phospho-Bad and 14-3-3 in ischemic stroke model.

Immortalization of Rat Kidney Glomerular Mesangial Cell and Its Coculture with Glomerular Epithelial Cell

  • Toshinobu Kida;Sachi Fujishima;Masatoshi Matsumra;Wang, Pi-Chao
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.5 no.2
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    • pp.92-98
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    • 2000
  • Mesangial cell has several key roles in thee control of glomerular function: it partocipates in the regulation of glomerular filtration rate, macromolecular clearance, and as both a source and target of numerous hormones and autocrines. Many of these insights into mesangial cell function have been obtained by studying mesangial cells in culture. However, no suitble cell lines have established yet. We here reported the immortalization of rat kidney glomeruar mesangial cell by transfection of E6 and E7 genes of human papillomavirus type 16 (HPV-16) via electroporation and lipofection. The reslts showed that only electroporation could transfect the genes to mesangial cells and the transfected cells maintained the viability for longer than 6 months. Fluorescence microscopic observation showed that cellular contractility and phagocytosis, which are the two main phenotypes of mesangial cells with rat glomerular epithelial cells showed that the growth of mesangial dells was suppressed by epithelial cell, but the growth of epithelisl cells was enhanced by mesangial cells. Moreover, Such results may imply that the glomerular cell-cell interaction plays an important role in the regulation of cell proliferation and differentiation.

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Deposition and Absorbance Characteristics of Copolymer LB Films (공중합체 고분자 LB막의 누적 및 흡광도 특성)

  • Shin, Hoon-Kyu;Choi, Yong-Sung;Lee, Burm-Jong;Chang, Jeong-Soo;Kwon, Young-Soo
    • Proceedings of the KIEE Conference
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    • 1995.07c
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    • pp.1196-1198
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    • 1995
  • In this paper, stability improvement of fragile LB films was attempted by monolayers at the air-water interface and crosslinking of the resulting LB films. The spreading polymers were synthesized by radical copolymerization of monoalkyl with oligoethyleneglycol methyl ether, and poly(allylamine) was employed as the subphase polymer. The monolayer properties have been studied by the surface pressure-area($\pi$-A) isotherms. Interaction between polymers and metal ions at the air-water interface and in their LB films were investigated. From the FT-IR(Reflection and Transmission) spectra, the formation of carboxylate ions and the relative orientation of the side chains could be confined. The monolayers were transferable on various substrates, and the resulting LB films were characterized by SEM and VIS-UV absorbance.

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A SIMPLIFIED TREATMENT OF GRAVITATIONAL INTERACTION ON GALACTIC SCALES

  • Trippe, Sascha
    • Journal of The Korean Astronomical Society
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    • v.46 no.1
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    • pp.41-47
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    • 2013
  • I present a simple scheme for the treatment of gravitational interactions on galactic scales. In anal- ogy with known mechanisms of quantum field theory, I assume ad hoc that gravitation is mediated by virtual exchange particles-gravitons-with very small but non-zero masses. The resulting den- sity and mass profiles are proportional to the mass of the gravitating body. The mass profile scales with the centripetal acceleration experienced by a test particle orbiting the central mass, but this comes at the cost of postulating a universal characteristic acceleration $a_0{\approx}4.3{\times}10^{-12}msec^{-2}$ (or $8{\pi}a_0{\approx}1.1{\times}10^{-10}msec^{-2}$). The scheme predicts the asymptotic flattening of galactic rotation curves, the Tully-Fisher/Faber-Jackson relations, the mass discrepancy-acceleration relation of galaxies, the surface brightness-acceleration relation of galaxies, the kinematics of galaxy clusters, and "Renzo's rule" correctly; additional (dark) mass components are not required. Given that it is based on various ad-hoc assumptions and given further limitations, the scheme I present is not yet a consistent theory of gravitation; rather, it is a "toy model" providing a convenient scaling law that simplifies the description of gravity on galactic scales.