• 제목/요약/키워드: molecular interface

검색결과 432건 처리시간 0.022초

나노구조기판의 형상 및 온도변화에 따른 액체 클러스터의 거동에 대한 분자동역학적 연구 (Molecular Dynamics Study on Behaviors of Liquid Cluster with Shape and Temperature of Nano-Structure Substrate)

  • 고선미;정흥철;;최경민;김덕줄
    • 한국분무공학회지
    • /
    • 제13권1호
    • /
    • pp.34-41
    • /
    • 2008
  • Molecular dynamic simulations have been carried out to study the effect of the nano-structure substrate and its temperature on cluster laminating. The interaction between substrate molecules and liquid molecules was modeled in the molecular scale and simulated by the molecular dynamics method in order to understand behaviors of the liquid cluster on nano-structure substrate. In the present model, the Lennard-Jones potential is applied to mono-atomic molecules of argon as liquid and platinum as nano-structure substrate to perform simulations of molecular dynamics. The effect of wettability on a substrate was investigated for the various beta of Lennard-Jones potential. The behavior of the liquid cluster and nano-structure substrate depends on interface wettability and function of molecules force, such as attraction and repulsion, in the collision progress. Furthermore, nano-structure substrate temperature and beta of Lennard-Jones potential have effect on the accumulation ratio. These results of simulation will be the foundation of coating application technology for micro fabrication manufacturing.

  • PDF

TP53I11 suppresses epithelial-mesenchymal transition and metastasis of breast cancer cells

  • Xiao, Tongqian;Xu, Zhongjuan;Zhang, Hai;Geng, Junsa;Qiao, Yong;Liang, Yu;Yu, Yanzhen;Dong, Qun;Suo, Guangli
    • BMB Reports
    • /
    • 제52권6호
    • /
    • pp.379-384
    • /
    • 2019
  • Epithelial-mesenchymal transition (EMT) is widely-considered to be a modulating factor of anoikis and cancer metastasis. We found that, in MDA-MB-231 cells, TP53I11 (tumor protein P53 inducible protein 11) suppressed EMT and migration in vitro, and inhibited metastasis in vivo. Our findings showed that hypoxic treatment upregulated the expression of $HIF1{\alpha}$, but reduced TP53I11 protein levels and TP53I11 overexpression reduced $HIF1{\alpha}$ expression under normal culture and hypoxicconditions, and in xenografts of MDA-MB-231 cells. Considering $HIF1{\alpha}$ is a master regulator of the hypoxic response and that hypoxia is a crucial trigger of cancer metastasis, our study suggests that TP53I11 may suppress EMT and metastasis by reducing $HIF1{\alpha}$ protein levels in breast cancer cells.

열역학 물성 예측을 위한 분자 시뮬레이션 소프트웨어의 개발 (Development of Molecular Simulation Software for the Prediction of Thermodynamic Properties)

  • 장재언
    • Korean Chemical Engineering Research
    • /
    • 제49권3호
    • /
    • pp.361-366
    • /
    • 2011
  • 몬테칼로 시뮬레이션 방법을 사용하여 유기화합물의 열역학적 물성을 예측하는 새로운 분자 시뮬레이션 소프트웨어를 개발하였다. 분자 구조, 분자간 포텐셜 에너지 함수와 엄밀한 통계역학적 원리로부터 많은 분자들을 포함한 계의 거동에 대한 확률 분포를 구하고 거시적인 계의 열역학적 물성을 계산한다. 본 연구에서 개발된 소프트웨어 cheMC는 윈도우즈 플랫폼에 기반하여 사용자 접근성이 좋고, 가시화 도구 및 차트 생성 기능 등 직관적인 인터페이스로 시뮬레이션 관리가 쉽다. 분자 시뮬레이션은 기존의 상태 방정식을 사용한 열역학 물성 연구를 보완하고, 향후 그 역할이 점점 더 커질 것으로 기대된다.

CO STUDY OF THE H II REGION SHARPLESS 301

  • JUNG JAE HOON;LEE JUNG-Kyu;YOON TAE SEOG;KANG YONG HEE
    • 천문학회지
    • /
    • 제34권3호
    • /
    • pp.157-166
    • /
    • 2001
  • The molecular cloud associated with the H II region S301 has been mapped in the J = 1-0 transitions of $^{12}CO$ and $^{13}CO$ using the 13.7 m radio telescope of Taeduk Radio Astronomy Observatory. The cloud is elongated along the north-south direction with two strong emission components facing the H II region. Its total mass is $8.7 {\times} 10^3 M{\bigodot}$. We find a velocity gradient of the molecular gas near the interface with the optical H II region, which may be a signature of interaction between the molecular cloud and the H II region. Spectra of CO, CS, and HCO+ exhibit line splitting even in the densest part of the cloud and suggests the clumpy structure. The radio continuum maps show that the ionzed gas is distributed with some asymmetry and the eastern part of the H II region is obscured by the molecular cloud. We propose that the S301 H II region is at the late stage of the champagne phase, but the second generation of stars has not yet been formed in the postshock layer.

  • PDF

Biochemical Characterization of Oligomerization of Escherichia coli GTP Cyclohydrolase I

  • Lee, Soo-Jin;Ahn, Chi-Young;Park, Eung-Sik;Hwang, Deog-Su;Yim, Jeong-Bin
    • BMB Reports
    • /
    • 제35권3호
    • /
    • pp.255-261
    • /
    • 2002
  • GTP cyclohydrolase I (E.C. 3.5.4.16) is a homodecameric protein that catalyzes the conversion of GTP to 7,8-dihydroneopterin triphosphate (H2NTP), the initial step in the biosynthesis of pteridines. It was proposed that the enzyme complex could be composed of a dimer of two pentamers, or a pentamer of tightly associated dimers; then the active site of the enzyme was located at the interface of three monomers (Nar et al. 1995a, b). Using mutant enzymes that were made by site-directed mutagenesis, we showed that a decamer of GTP cyclohydrolase I should be composed of a pentamer of five dimers, and that the active site is located between dimers, as analyzed by a series of size exclusion chromatography and the reconstitution experiment. We also show that the residues Lys 136, Arg139, and Glu152 are of particular importance for the oligomerization of the enzyme complex from five dimers to a decamer.

Prediction of Deterioration Rate for Composite Material by Moisture Absorption

  • Kim, Yun-Hae;An, Seung-Jun;Jo, Young-Dae;Bae, Chang-Won;Moon, Kyung-Man
    • Journal of Advanced Marine Engineering and Technology
    • /
    • 제34권2호
    • /
    • pp.296-302
    • /
    • 2010
  • If the fiber reinforced plastic is exposed to the moisture for a long period of time, most of moisture absorption occurs on the resin place, thus dropping cohesiveness between the molecules as the water molecules permeated between high molecular chains grant high molecular mobility and flexibility. Also as the micro crack occurs due to the permeation of moisture on the interface of glass fiber and epoxy resin, it is developed to the overall damage of interface place. Hence, the study on absorption is essential as the mechanical and physical properties of fiber reinforced composites are reduced. However, the study on absorption has the inconvenience needing to expose composite materials to fresh water or seawater for 1 month or up to 1 year. Therefore, this study has exposed fiber reinforced composites to fresh water and has developed a model with an accuracy of 98% after comparing the analysis value obtained by using ANSYS while basing on the experimental value of property decline by absorption and the basic properties of glass fiber and epoxy resin used in the experiment.