• Title/Summary/Keyword: Surface activation

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Modulation of Life and Death by the Tumor Necrosis Factor Receptor-Associated Factors (TRAFs)

  • Lee, Na-Kyung;Lee, Soo-Young
    • BMB Reports
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    • v.35 no.1
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    • pp.61-66
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    • 2002
  • The TNF receptor-associated factor (TRAF) family is a group of adapter proteins that link a wide variety of cell surface receptors. Including the TNF and IL-1 receptor superfamily to diverse signaling cascades, which lead to the activation of NF-${\kappa}B$ and mitogen-activated protein kinases. In addition, TRAFs interact with a variety of proteins that regulate receptor-induced cell death or survival. Thus, TRAF-mediated signals may directly induce cell survival or interfere with the death receptor-induced apoptosis.

Immunomodulatory activity of Salicornia herbacea L. Components

  • Im, Sun-A;Kim, Goo-Whan;Lee, Chong-Kil
    • Natural Product Sciences
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    • v.9 no.4
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    • pp.273-277
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    • 2003
  • Salicornia herbacea is an annual herb growing in salt marshes and on muddy seashores. Salicornia herbacea has been used as a fork medicine as well as a seasoned vegetable. In fork medicine, Salicornia herbacea has been used to treat a variety of diseases such as constipation, obesity, diabetes, asthma, arthritis and cancer. However, the biological mechanisms for these activities have not been characterized, nor the active components. The immunomodulatory activity of Salicornia herbacea components were studied in the present study. The components of Salicornia herbacea were prepared from the whole plant by passage through a fine screen, and then dialyzed against PBS overnight. Immunomodulatory activities of the Salicornia herbacea components were examined on a mouse macrophage cell line, RAW 264.7 cells. The Salicornia herbacea components were shown to stimulate cytokine production, nitric oxide release, and expression of surface molecules in a dose dependent manner. The Salicornia herbacea components also induced further differentiation of slightly adherent RAW 264.7 cell into strongly adherent macrophages. These results indicate that Salicornia herbacea contains immunomodulator(s) that induces activation of macrophages.

Self-activated Graphene Gas Sensors: A Mini Review

  • Kim, Taehoon;Eom, Tae Hoon;Jang, Ho Won
    • Journal of Sensor Science and Technology
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    • v.29 no.4
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    • pp.220-226
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    • 2020
  • Graphene has been widely considered a promising candidate for high-quality chemical sensors, owing to its outstanding characteristics, such as sensitive gas adsorption at room temperature, high conductivity, high flexibility, and high transparency. However, the main drawback of a graphene-based gas sensor is the necessity for external heaters due to its slow response, incomplete recovery, and low selectivity at room temperature. Conventional heating devices have limitations such as large volume, thermal safety issues, and high power consumption. Moreover, metal-based heating systems cannot be applied to transparent and flexible devices. Thus, to solve this problem, a method of supplying the thermal energy necessary for gas sensing via the self-heating of graphene by utilizing its high carrier mobility has been studied. Herein, we provide a brief review of recent studies on self-activated graphene-based gas sensors. This review also describes various strategies for the self-activation of graphene sensors and the enhancement of their sensing properties.

Comparison of the Onset Times of Antigravity Flexor Muscle Activity During Head Lift in Supine Position between Children with Cerebral Palsy and Healthy Children (누운자세에서 머리들기 시 정상아동과 뇌성마비아동 간의 항굴근 수축 개시 시간 비교)

  • Hwang Seon-Gwan;Hwang Byong-Yong
    • The Journal of Korean Physical Therapy
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    • v.15 no.4
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    • pp.488-497
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    • 2003
  • The purpose of this study was to compare the muscle onset time of sternocleidomastoid (SCM) and rectus abdominalis (RA) muscle activity during head lift in supine position between cerebral palsy and healthy children. Ten cerebral palsy children and 10 age, sex-matched healthy children were recruited for this study. Muscle activity of the SCM and RA were collected by surface electromyography (MP100SWS). Results demonstrated that the muscle onset time order was not significantly different between cerebral palsy children and healthy children. However, the DMHT and ST between SCM and RA during head lift in supine position were significantly shorter in healthy children than in cerebral palsy children. Further studies are needed to clarify the mechanism of differences in muscle activation patterns during head lift in supine position in cerebral palsy children compared with healthy children.

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Differential regulation of phospho-p38 and phospho-ERK by TCDD

  • Kim, Ho-jun;Cho, Sung-whan;Son, Hwa-young;Yoon, Won-kee;Jeong, Kyung-shik;Ryu, Si-yun
    • Proceedings of the Korean Society of Veterinary Pathology Conference
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    • 2003.10a
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    • pp.42-42
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    • 2003
  • The contamination of the environment with pollutants is one of the main problems of modern life, and the levels pollution in industrialized regions are giving raise to increased public concern. The mitogen-activated protein kinase (MAP kinase) are playa pivotal role in the regulation of important cellular functions by activation of specific signal transduction pathways from cell the surface to the nuclei. Three major subgroups of MAP kinases have been identified, and these comprise the extracellular signal-regulated kinase (ERK), the c-Jun amino-terminal kinase (JNK), and the p38 MAP kinases [1-3]. Herein, we investigated the effect of regulation of phospho-JNK (p-JNK), phospho-p38 (p-p38) and phospho-ERK (p-ERK) by TCDD. (omitted)

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Characteristics of $TiO_2$ Powders Prepared by Freeze Drying Method (동결건조법으로 제조한 $TiO_2$의 특성)

  • 윤기현;박승순
    • Journal of the Korean Ceramic Society
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    • v.25 no.3
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    • pp.277-283
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    • 1988
  • Extremely fine $TiO_2$ powders were synthesized from titanium chloride by the precipitation and freeze drying method. The phase transformation and electrical conductivity were investigated as a function of temperature. X-ray analysis showed that the phase transformation of the synthesized powder from the anatase to rutile occured at 64$0^{\circ}C$ and finished at 92$0^{\circ}C$ due to small particle size and large specific surface area. The activation energy obtained from electrical conductivity vs. temperature was about 1.63eV. This relatively large value was due to porosity in the specimen.

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Electrochemical Impulse Oscillations at the Platinum Group Electrode Interfaces (백금족 전력 계면에서 전기화학적 Impulse 발진)

  • 전장호;손광철;라극환
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.32A no.3
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    • pp.143-151
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    • 1995
  • The electrochemical impulse oscillations of the cathodic currents at the platinum group (Pt, Pd) electrode/(0.05M KHC$_{8}H_{4}O_{4}$) buffer solution interfaces have been studied using voltammetric, chronoamperometric, and electrochemical impedance methods. The periodic impulses of the cathodic currents are the activation controlled currents due to the hydrogen evolution reaction, and depend on the fractional surface coverage of the adsorbed hydrogen intermediate and potential. The oscillatory mechanism of the cathodic current impulses is connected with the unstable steady state of negative differential resistance. The widths and periods of the cathodic current impulses are 4ms or 5ms and 152.5ms or 305ms, respectively. The H$^{+}$ discharge reaction step is 38 or 61 times faster thatn the recombination reaction steps and the H$^{+}$ mass transport processes. The atom-atom recombination reaction step is twice faster thatn the atom-ion recombination reaction step. The two kinds of active sites corresponding to the atom-atom and atom-ion recombination reaction steps exist on the platinum group electrode surfaces.

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Local Oxidation Characteristics on Implanted 4H-SiC by Atomic Force Microscopy (원자힘 현미경을 이용한 이온 주입된 4H-SiC 상의 국소 산화 특성)

  • Lee, Jung-Ho;Ahn, Jung-Joon;Koo, Sang-Mo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.25 no.4
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    • pp.294-297
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    • 2012
  • In this work, local oxidation behavior in phosphorous ion-implanted 4H-SiC has been investigated by using atomic force microscopy (AFM). The AFM-local oxidation (AFM-LO) has been performed on the implanted samples, with and without activation anneal, using an applied bias (~25 V). It has been clearly shown that the post-implantation annealing process at $1,650^{\circ}C$ has a great impact on the local oxidation rate by electrically activating the dopants and by modulating the surface roughness. In addition, the composition of resulting oxides changes depending on the doping level of SiC surfaces.

Natural killer T cell and pathophysiology of asthma

  • Jang, Gwang Cheon
    • Clinical and Experimental Pediatrics
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    • v.53 no.2
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    • pp.136-145
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    • 2010
  • Natural killer T (NKT) cell is a special type of T lymphocytes that has both receptor of natural killer (NK) cell (NK1.1, CD161c) and T cell (TCR) and express a conserved or invariant T cell receptor called $V{\alpha}14J{\alpha}18$ in mice or Va24 in humans. Invariant NKT (iNKT) cell recognizes lipid antigen presented by CD1d molecules. Marine-sponge-derived glycolipid, ${\alpha}-galactosylceremide$ (${\alpha}-GalCer$), binds CD1d at the cell surface of antigen-presenting cells and is presented to iNKT cells. Within hours, iNKT cells become activated and start to secrete Interleukin-4 and $interferon-{\gamma}$. NKT cell prevents autoimmune diseases, such as type 1 diabetes, experimental allergic encephalomyelitis, systemic lupus erythematous, inflammatory colitis, and Graves' thyroiditis, by activation with ${\alpha}-GalCer$. In addition, NKT cell is associated with infectious diseases by mycobacteria, leshmania, and virus. Moreover NKT cell is associated with asthma, especially CD4+ iNKT cells. In this review, I will discuss the characteristics of NKT cell and the association with inflammatory diseases, especially asthma.

Surface Metallization of Polyethylene Films Modified by Radiation Grafting of N-vinyl Pyrollidone (감마선 자극에 의한 금속이온 이식 도전성 폴리머)

  • A. Aal;V. V. Khutoryanskiy;Z. S. Nurkeeva;G. A. Mun;Soh, Dea-Wha
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2003.10a
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    • pp.403-406
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    • 2003
  • Poyethylene(PE) films could be modified by radiation grafting of N-vinyl pyrollidone(NVP) using radiation. FTIR spectra was used to confirm the modification of PE films. The modified films were activated by one-step or two-step methods for electroless Cu plating. Morphology of metallized films has been investigated. Electroless Cu plating onto the modified films depends mainly on the grafting degree and activation type. The electrical conductivity and adhesion of the metallized films has been investigated and tested in regard of grafting degree of samples.

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