• 제목/요약/키워드: signal molecules

검색결과 402건 처리시간 0.025초

집적광학과 광통신을 위한 비선형광학 유기물질 (Organic nonlinear optic materials for intergated optics and optical teclecommunications)

  • 윤촌섭
    • 한국광학회:학술대회논문집
    • /
    • 한국광학회 1991년도 광학 및 양자전자학 워크샵
    • /
    • pp.5-8
    • /
    • 1991
  • New nonliner organic materials have been developed for all-optical signal processing. The organic materials possess many interesting features for this purpose. Unlike inorganic molecules the delocalized $\pi$-electron distribution and intramolecular charge transfer mevhanism allows certain organic molecules to respond highly anharmonically to an external field. In the present paper the origins of nonlinear phenomena, advantages of orgnic materials and structures of organic devices will be discussed.

  • PDF

Targeting Cell-Cell and Cell-Matrix Interactions and Its Therapeutic Applications

  • Kim, In-San
    • 대한약학회:학술대회논문집
    • /
    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-1
    • /
    • pp.100-101
    • /
    • 2003
  • Cell-cell and cell-matrix interaction is clearly required for metazoans not only to hold their cells together but also to conduct more sophisticated biological processes. Each cell has adhesion molecules on its cell membrane to link extracellular matrix and adjacent cells to the intracellular cytoskeleton, and also to transduce signals. In complex metazoans, information is transmitted from one cell to another by mechanisms such as direct intercellular communication, soluble signal molecules among distant cells, and local cellular environments formed by highly specialized extracellular matrix. (omitted)

  • PDF

Signaling Molecules at the Conceptus-Uterine Interface during Early Pregnancy in Pigs

  • Seo, Heewon;Choi, Yohan;Shim, Jangsoo;Kim, Mingoo;Ka, Hakhyun
    • 한국수정란이식학회지
    • /
    • 제27권4호
    • /
    • pp.211-221
    • /
    • 2012
  • The process of embryo implantation requires physical contact and physiological communication between the conceptus trophectoderm and the maternal uterine endometrium. During the peri-implantation period in pigs, the conceptus undergoes significant morphological changes and secretes estrogens, the signal for maternal recognition of pregnancy. Estrogens secreted from the conceptus act on uterine epithelia to redirect $PGF_2{\alpha}$, luteolysin, secretion from the uterine vasculature to the uterine lumen to prevent luteolysis as well as to induce expression of endometrial genes that support implantation and conceptus development. In addition, conceptuses secrete cytokines, interferons, growth factors, and proteases, and in response to these signals, the uterine endometrium produces hormones, protease inhibitors, growth factors, transport proteins, adhesion molecules, lipid molecules, and calcium regulatory molecules. Coordinated interactions of these factors derived from the conceptus and the uterus play important roles in the process of implantation in pigs. To better understand mechanism of implantation process in pigs, this review provides information on signaling molecules at the conceptus-uterine interface during early pregnancy, including recently reported data reported.

적외선 배경신호 처리를 통한 OES 기반 PECVD공정 모니터링 정확도 개선 (OES based PECVD Process Monitoring Accuracy Improvement by IR Background Signal Subtraction from Emission Signal)

  • 이진영;서석준;김대웅;허민;이재옥;강우석
    • 반도체디스플레이기술학회지
    • /
    • 제18권1호
    • /
    • pp.5-9
    • /
    • 2019
  • Optical emission spectroscopy is used to identify chemical species and monitor the changes of process results during the plasma process. However, plasma process monitoring or fault detection by using emission signal variation monitoring is vulnerable to background signal fluctuations. IR heaters are used in semiconductor manufacturing chambers where high temperature uniformity and fast response are required. During the process, the IR lamp output fluctuates to maintain a stable process temperature. This IR signal fluctuation reacts as a background signal fluctuation to the spectrometer. In this research, we evaluate the effect of infrared background signal fluctuation on plasma process monitoring and improve the plasma process monitoring accuracy by using simple infrared background signal subtraction method. The effect of infrared background signal fluctuation on plasma process monitoring was evaluated on $SiO_2$ PECVD process. Comparing the $SiO_2$ film thickness and the measured emission line intensity from the by-product molecules, the effect of infrared background signal on plasma process monitoring and the necessity of background signal subtraction method were confirmed.

Fabrication of Chitosan-gold Nanocomposites Combined with Optical Fiber as SERS Substrates to Detect Dopamine Molecules

  • Lim, Jae-Wook;Kang, Ik-Joong
    • Bulletin of the Korean Chemical Society
    • /
    • 제35권1호
    • /
    • pp.25-29
    • /
    • 2014
  • This research was aimed to fabricate an optical fiber-based SERS substrate which can detect dopamine neurotransmitters. Chitosan nanoparticles (NPs) were firstly anchored on the surface of optical fiber, and then gold layer was subsequently deposited on the anchored chitosan NPs via electroless plating method. Finally, chitosan-gold nanocomposites combined with optical fiber reacted with dopamine molecules of 100-1500 mg/day which is a standard daily dose for Parkinson's disease patients. The amplified Raman signal at $1348cm^{-1}$ obtained from optical fiber-based SERS substrate was plotted versus dopamine concentrations (1-10 mM), demonstrating an approximate linearity of Y = 303.03X + 2385.8 ($R^2$ = 0.97) with narrow margin errors. The optical fiber-based Raman system can be potentially applicable to in-vitro (or in-vivo) detection of probe molecules.

Statistical Analysis of Fluorescence Correlation Spectroscopy of Ultra Low Concentration Molecules with a Confocal Microscope

  • Lee, Soon-Hyouk;Lim, Gyu-Chang;Kim, Soo-Yong;Kim, Eun-Kyung;Kim, Hak-Sung;Kim, Sok-Won
    • Journal of the Optical Society of Korea
    • /
    • 제12권3호
    • /
    • pp.170-173
    • /
    • 2008
  • In this study, we simulated a statistical model of FCS(fluorescence correlation spectroscopy) based on a Poisson process to understand and explain observations of the experiment performed on molecules of ultra-low concentration by the home-built laser-scanning confocal microscope. The statistical model confirmed that the relative mean square amplitude of fluctuations is shown to be inversely proportional to the average number of molecules, even in the ultra-low concentration, if some conditions are satisfied. Signal-to-noise ratio and the variability of dwelling time under the confocal volume were found to be effective conditions for the experiment.

CD137-CD137 Ligand Interactions in Inflammation

  • Kwon, Byung-Suk
    • IMMUNE NETWORK
    • /
    • 제9권3호
    • /
    • pp.84-89
    • /
    • 2009
  • The main stream of CD137 studies has been directed to the function of CD137 in $CD8^+$ T-cell immunity, including its anti-tumor activity, and paradoxically the immunosuppressive activity of CD137, which proves to be of a great therapeutic potential for animal models of a variety of autoimmune and inflammatory diseases. Recent studies, however, add complexes to the biology of CD137. Accumulating is evidence supporting that there exists a bidirectional signal transduction pathway for the CD137 receptor and its ligand (CD137L). CD137/CD137L interactions are involved in the network of hematopoietic and nonhematopoietic cells in addition to the well characterized antigen-presenting cell-T cell interactions. Signaling through CD137L plays a critical role in the differentiation of myeloid cells and their cellular activities, suggesting that CD137L signals trigger and sustain inflammation. The overall consequence might be that the amplified inflammation by CD137L enhances the T-cell activity together with CD137 signals by upregulating costimulatory molecules, MHC molecules, cell adhesion molecules, cytokines, and chemokines. Solving this outstanding issue is urgent and will have an important clinical implication.

인공 항원제시세포의 표면 분자의 특성 및 상호작용이 T 세포 활성화에 미치는 영향 (The effects of properties and interactions of surface molecules in antigen presenting cells on T cell activation)

  • 민영실;강윤중
    • 융합정보논문지
    • /
    • 제10권6호
    • /
    • pp.164-176
    • /
    • 2020
  • 인체 적응 면역 반응을 일으키는데 중요한 항원 특이적 T 세포를 활용한 면역 세포 치료에서 T 세포를 체외에서 배양하고 클론 확장시키는 과정은 매우 섬세하고 복잡하여 조절하기가 쉽지 않아 T 세포의 활성화와 클론 확장을 유도하면서도 조절 및 취급이 용이한 인공 항원제시세포 개발의 필요성이 대두되고 있다. 인공 항원제시세포는 인체의 항원제시세포의 세포 표면 분자와 작용을 모방하게 되는데, 기본적인 신호 분자인 MHC-항원 복합체, 공동 자극 분자, 그리고 용해성 면역 조절 분자를 필수적으로 발현하여야 한다. 또한 T 세포가 항원과 접촉할 때, 이들 분자들이 잘 조직화되어 작용하는 것이 효과적인 T 세포 활성화에 중요하다. 본 논문에서는 여러 인공 항원제시세포 제작 방법과 세포 표면 분자들의 결합 방법과 물리적인 특성이 T 세포와의 상호작용에 중요함을 고찰하였으며, 효과적인 T 세포 활성화를 유도하며 면역세포치료에 적용 가능한 인공항원제세세포의 제작 방법을 살펴보았다.

Transmembrane Signaling Model of a Serine Chemotaxis Receptor

  • Kim, Kyeong-Kyu;Hisao Yokota;Kim, Sung-Hou
    • 한국생물물리학회:학술대회논문집
    • /
    • 한국생물물리학회 1999년도 학술발표회 진행표 및 논문초록
    • /
    • pp.20-20
    • /
    • 1999
  • Bacterial chemotaxis receptors are some of the simplest and most studied transmembrane receptors. Their simple signaling pathway has elements relevant for understanding the mechanisms for signal recognition, transduction through the membrane, relays among the molecules in the pathway, and adaptation to a persistent signal.(omitted)

  • PDF

Dynamics and Transport of Molecules Studied by Transient Grating Method : Methyl Red in Solution

  • 김선희;김성규
    • Bulletin of the Korean Chemical Society
    • /
    • 제17권4호
    • /
    • pp.365-373
    • /
    • 1996
  • Time profile of the transient grating signal induced by a nanosecond pulsed laser excitation of methyl red is investigated in alcohols and toluene at several solvent temperatures. The signal decays biexponentially with well-separated time constants; the faster decay is identified as due to thermal diffusion of the solvents and the slower one as mainly due to translational diffusion of the solute. The measured translational diffusion constants of methyl red in toluene are close to a hydrodynamic prediction with a slip boundary condition while those in alcohols are larger by 30% and increase slightly with the size of alcohols. We compare the results with modified hydrodynamic models.