• Title/Summary/Keyword: NA sensors

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CD72 is a Negative Regulator of B Cell Responses to Nuclear Lupus Self-antigens and Development of Systemic Lupus Erythematosus

  • Takeshi Tsubata
    • IMMUNE NETWORK
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    • v.19 no.1
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    • pp.1.1-1.13
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    • 2019
  • Systemic lupus erythematosus (SLE) is the prototypic systemic autoimmune disease characterized by production of autoantibodies to various nuclear antigens and overexpression of genes regulated by IFN-I called IFN signature. Genetic studies on SLE patients and mutational analyses of mouse models demonstrate crucial roles of nucleic acid (NA) sensors in development of SLE. Although NA sensors are involved in induction of antimicrobial immune responses by recognizing microbial NAs, recognition of self NAs by NA sensors induces production of autoantibodies to NAs in B cells and production of IFN-I in plasmacytoid dendritic cells. Among various NA sensors, the endosomal RNA sensor TLR7 plays an essential role in development of SLE at least in mouse models. CD72 is an inhibitory B cell co-receptor containing an immunoreceptor tyrosine-based inhibition motif (ITIM) in the cytoplasmic region and a C-type lectin like-domain (CTLD) in the extracellular region. CD72 is known to regulate development of SLE because CD72 polymorphisms associate with SLE in both human and mice and CD72-/- mice develop relatively severe lupus-like disease. CD72 specifically recognizes the RNA-containing endogenous TLR7 ligand Sm/RNP by its extracellular CTLD, and inhibits B cell responses to Sm/RNP by ITIM-mediated signal inhibition. These findings indicate that CD72 inhibits development of SLE by suppressing TLR7-dependent B cell response to self NAs. CD72 is thus involved in discrimination of self-NAs from microbial NAs by specifically suppressing autoimmune responses to self-NAs.

Spectroscopic characterization of electroluminescent ZnS:Cu,Cl phosphor coated by sol-gel process

  • Lee, You-Hui;Han, Chi-Hwan;Han, Sang-Do;Chang, Mi-Youn;Sharma, Gaytri.;Park, Youn-Bong
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07b
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    • pp.1323-1326
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    • 2005
  • The photoluminescence, electroluminescence and surface properties of ZnS:Cu,Cl phosphor coated by sol-gel process were studies. Na-silicate was used as precursor coating material. pH of solution and the concentration of Na-silicate are the important conditions to obtain the uniform coating on the phosphors. Also, the electroluminescent devices were made with Na-silicate coated phosphor. The spectroscopic characterization is performed by photospectrometer.

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A study on improving sensitivity to CO2 gases of Na solid electrolyte sensors adding CaO (CaO를 첨가한 Na고체전해질 센서의 CO2가스 감도향상에 관한 연구)

  • Kwak, Jong-Sig;Seo, Moo-Gyo;Choi, Soon-Don;Lee, Duk-Dong
    • Journal of Sensor Science and Technology
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    • v.11 no.4
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    • pp.218-223
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    • 2002
  • NASICON sensors that the NASICON electrolytes with various CaO amounts were sintered at low temperature($900^{\circ}C$), were fabricated to improve $CO_2$ sensitivity and stability in sensing behaviors. The manufactured device was shown good sensing characteristics and stability of output electromotive force at $250^{\circ}C$, comparatively low operating temperature.

Characteristics of thick film Co2 sensors attached with Na2CO3-CaCO3 auxiliary phases (Na2CO3-CaCO3 보조상을 사용한 후막형 Co2 센서의 특성연구)

  • Shim, H.B.;Choi, J.W.;Kang, J.H.;Yoo, K.S.
    • Journal of Sensor Science and Technology
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    • v.15 no.3
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    • pp.168-172
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    • 2006
  • Potentiometric $CO_{2}$ sensors were fabricated using a NASICON ($Na_{1+x}Zr_{2}Si_{X}P_{3-X}O_{12}$, 1.8 < x < 2.4) thick film and auxiliary layers. The powder of a precursor of NASICON with high purity was synthesized by a sol-gel method. By using the NASICON paste, an electrolyte was prepared on the alumina substrate by screen printing and then sintered at $1000^{\circ}C$ for 4 h. A series of $Na_{2}CO_{3}-CaCO_{3}$ auxiliary phases were deposited on the Pt sensing electrode. The electromotive force (emf) values were linearly dependent on the logarithm of $CO_{2}$ concentration in the range between 1,000 and 10,000 ppm. The device attached with $Na_{2}CO_{3}-CaCO_{3}$ (1:2 in mol.%) showed good sensing properties in the low temperatures.

Origami inspired Temperature Sensor based on Stimuli-Responsive Hydrogel (종이접기 기반 자극 반응성 하이드젤 온도 센서 연구)

  • Na, Jun-Hee
    • Journal of Sensor Science and Technology
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    • v.26 no.1
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    • pp.35-38
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    • 2017
  • A thermally responsive hydrogel has reversibility with temperature during swelling. Here, we proposed origami inspired temperature sensor by using multi-layered hydrogel film. The formation of patterned stripes on microscale film drives bending to an angle that can be controlled linearly. Although temperature range was not wide, measured sensitivity of sensors has high resolution and accuracy. It providing a powerful platform for the design of sensitive sensors and that easily adapt other type of sensors in microscale.

Thermodynamic Analysis of Solid Electrolyte $CO_2$ Sensor in Continuous and Discontinuous Flow Systems (연속 기체흐름계 및 일시 기체흐름계에서의 고체 전해질 $CO_2$ 가스센서의 열역학적 분석)

  • Choi, Soon-Don
    • Journal of Sensor Science and Technology
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    • v.7 no.5
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    • pp.319-326
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    • 1998
  • Anodic half-reaction in the $Na^+$ ionic sensors using $Na_2CO_3$ and $MCO_3$ ($M=Cs_2,K_2,Li_2,Ca$) as a sensitive membrane is derived in continuous flow system to explain $CO_2$ sensing characteristics. For various gas-sensitive membranes, a well known overall reaction, $MCO_3\;=\;MO\;+\;CO_2$, cannot be applied for the EMF behaviors of these kinds of sensors. So, the anodic reaction is found to involve $Na_2CO_3$ and $M^{++}$-containing oxide phases by employing the ion exchange reaction at the interface of solid electrolyte and the sensitive membrane to maintain ionic balance in the whole cell. Based on the electrode reaction derived in flow system, differences of cell potentials between continuous and discontinuous flow systems were also discussed. These EMF differences were considerably caused by the partial pressures of oxygen and $CO_2$ as well as irreversible chemical reactions between electrode materials and $CO_2$ atmosphere.

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Gas Sensing Characteristics and Preparation of SnO2 Nano Powders (SnO2 나노 분말의 합성 및 가스 감응 특성)

  • Lee, Ji-Young;Yu, Yoon-Sic;Yu, Il
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.24 no.7
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    • pp.589-593
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    • 2011
  • [ $SnO_2$ ]nano powders were prepared by solution reduction method using tin chloride($SnCl_2{\cdot}2H_2O$), hydrazine($N_2H_4$) and NaOH. The $SnO_2$ thick films for gas sensors were fabricated by screen printing method on alumina substrates and annealed at $300^{\circ}C$ in air, respectively. XRD patterns of the $SnO_2$ nano powders showed the tetragonal structure with (110) dominant orientation. The particle size of $SnO_2$ nano powders at the ratio of $SnCl_2:N_2H_4$+NaOH= 1:6 was about 60 nm. The sensing characteristics were investigated by measuring the electrical resistance of each sensor in a test box. Sensitivity of $SnO_2$ gas sensor to 5 ppm $CH_4$gas and 5 ppm $CH_3CH_2CH_3$ gas was investigated for various $SnCl_2:N_2H_4$+NaOH proportion. The highest sensitivity to $CH_4$ gas and $CH_3CH_2CH_3$ gas of $SnO_2$ sensors was observed at the $SnCl_2:N_2H_4$+NaOH= 1:8 and $SnCl_2:N_2H_4$+NaOH= 1:6, respectively. Response and recovery times of $SnO_2$ gas sensors prepared by $SnCl_2:N_2H_4$+NaOH= 1:6 was about 40 s and 30 s, respectively.

Sensitivity Characteristics of Acoustic Emission(AE) Sensor using the Lead-free (Na1,K)NbO3 Ceramics (무연 (Na1,K)NbO3 계 세라믹스를 이용한 AE센서의 감도특성)

  • Yoo, Ju-Hyun;Lee, Gab-Soo;Hong, Jae-Il
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.20 no.3
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    • pp.218-222
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    • 2007
  • In this study, Acoustic emission(AE) sensors were fabricated using lead-free piezoelectric ceramics for prohibiting environmental pollution. Structure of AE sensors were designed as Langvin type air backing form. Here, the piezoelectic element was used as PZT(EC-65)(AE1) and NKN(AE2), respectively. The measured resonant frequency, the maximum sensitivity frequency and sensitivity of AE sensors were as follows ; 143 kHz, 29.4 kHz and 69.3 dB in AE1 and 179 kHz, 29.4 kHz and 66.3dB in AE2, respectively.

Embeddable reference sensors for corrosion monitoring in concrete structures (콘크리트 구조물의 부식감시용 매설형 기준전극의 전기화학적 안정성에 관한 연구)

  • Ha, Tae-Hyun;Bae, Jeong-Hyo;Ha, Yoon-Cheol;Lee, Hyun-Goo;Kim, Dae-Kyeong
    • Proceedings of the KIEE Conference
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    • 2005.11a
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    • pp.160-163
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    • 2005
  • Several sensors are involved in the cor개sion monitoring of concrete structures. This paper deals with the monitoring of concrete structures by embeddable reference sensors. $MnO_2$, MMO and graphite reference sensors are fabricated in the laboratory as suitable as embeddable type into the concrete structures. Sensors are embedded into the mortars and the performance was studied in the absence and presence of chloride ions. The electrochemical stability of the sensors was carried out for the exposure period of one year. Polarisation behaviour and impedance of the sensors in mortar was carried out in three aqueous solutions namely distilled water, 3% NaCl and natural sea water.

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Disturbance Elimination Performance Improvement of A Magnetic Levitation System by Array-Sensor Calibration (센서 배열의 보정에 의한 자기 부상 시스템의 외란 제거 성능 개선)

  • An, Myung-Kook;Na, Seung-You
    • Proceedings of the KIEE Conference
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    • 2002.11c
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    • pp.278-281
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    • 2002
  • In this paper we propose a controller which has the capability of disturbance measurement calibration for Cds array sensors in a magnetic levitation system. Steady state error due to environment light condition or external disturbance is corrected constantly. The correction is made by the sensors to measure the ball position of the system without additional deployment of sensors.

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