• Title/Summary/Keyword: C.V.A

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Carbon Monoxide as a Novel Central Pyrogenic Mediator

  • Jang, Choon-Gon;Lee, Seung-Jin;Yang, Sang-In;Kim, Jin-Hak;Sohn, Uy-Dong;Lee, Seok-Yong
    • Archives of Pharmacal Research
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    • v.25 no.3
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    • pp.343-348
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    • 2002
  • Carbon monoxide (CO) are produced by heme oxygenase (HO), and HO was detected in hypothalamus. However, the roles of CO produced in hypothalamus was not fully elucidated. So, we tested the effects of CO on body temperature because preoptic-anterior hypothalamus was known as the presumptive primary fever-producing site. CO-saturated aCSF ($4{\;}{\mu}l$, i.c.v.) and hemin ($10{\;}{\mu}g$, i.c.v.) elicited marked febrile response. Pretreatment with indomethacin completely inhibited CO- and hemin-induced fever. Zinc protoporphyrin-IX ($10{\;}{\mu}g$, i.c.v.) or ODQ ($50{\;}{\mu}g$, i.c.v.) partially reduced hemin-induced febrile response. Dibutyryl-cGMP ($100{\;}{\mu}g$, i.c.v.) produced profound febrile response and this febrile response was attenuated by indomethacin. These results indicate that endogenous CO may have a role as a pyrogenic mediator in CNS and CO-mediated pyresis is dependent on prostaglandin production and partially on activation of soluble guanylate cyclase.

UV/visible Absorption Spectrum and I-V Characteristics of Thermally Annealed $C_{22}$-Quinolium(TCNQ) Langmuir-Blodgett Films ($C_{22}$-quinolium(TCNQ) LB막의 열처리에 따른 UV/visible 흡광도와 I-V 특성)

  • 이상국;송민종;김태완;강도열
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1993.11a
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    • pp.137-140
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    • 1993
  • Electrical properties and thermal annealing effects of $C_{22}$-quinolium(TCNQ) Langmuir-Blodgett(LB) films were studied. Typical current-voltage(I-V) characteristics along the perpendicular direction chow an anomalous behavior of breakdown near the electric-field strength of $10^{6}$V/cm. To see the thermal influence of the specimen, current was measured as a function of temperature(20∼$180^{\circ}C$). It shows that the current increases about 4 orders of magnitude near 60∼$70^{\circ}C$ and remains constant far a while up to ∼$150^{\circ}C$ and then suddenly drops. Such increase of current near 60∼$70^{\circ}C$ seems tn be related to a softness of alkyl chains. Besides the electrical measurements, UV/visible absorption(300∼800 nm) of the thermally annealed sample was measured to see the internal-structure change. It is found that there are four characteristic peaks. At 494 nm, the optical absorption of the thermally annealed specimen at $60^{\circ}C$ starts increase and stays almost constant upto∼ $140^{\circ}C$. And eventually it disappears above $180^{\circ}C$. After heat treatment of the specimen up to $150^{\circ}C$, Uv/visible absorption was measured while cooling.

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A Study on the Piezoelectric Characteristic of P(VDF-TrFE) Copolymer Thin Film by Physical Vapor Deposition Method (진공증착법을 이용한 P(VDF-TrFE) 공중합체 박막의 압전특성에 관한 연구)

  • Park, S.H.
    • Journal of the Korean Vacuum Society
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    • v.17 no.3
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    • pp.220-225
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    • 2008
  • In this research, the P(VDF-TrFE) copolymer thin films were prepared by the physical vapor deposition and studied to their piezoelectric properties. In the case of a specimen produced by varying the deposition temperature from $260^{\circ}C$ to $300^{\circ}C$, its piezoelectric coefficient($d_{33}$) increased from 32.3pC/N to 36.28pC/N, and piezoelectric voltage coefficient($g_{33}$) from $793{\times}10^{-3}V{\cdot}m/N$ to $910.5{\times}10^{-3}V{\cdot}m/N$. On the basis of these experimental results, we concluded that the P(VDF-TrFE) copolymer thin film prepared at $300^{\circ}C$ showed the optimum piezoelectric properties. At the deposition temperature of $320^{\circ}C$, its piezoelectric coefficient(d33) decreased 25.3 pC/N and piezoelectric voltage coefficient($g_{33}$) $680{\times}10^{-3}V{\cdot}m/N$.

Evaluation of intracellular uptake of cyclic RGD peptides in integrin αvβ3-expressing tumor cells

  • Soyoung Lee;Young-Hwa Kim;In Ho Song;Ji Young Choi;Hyewon Youn;Byung Chul Lee;Sang Eun Kim
    • Journal of Radiopharmaceuticals and Molecular Probes
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    • v.6 no.2
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    • pp.92-101
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    • 2020
  • The cyclic Arg-Gly-Asp (cRGD) peptide is well-known as a binding molecule to the integrin αvβ3 receptor which is highly expressed on activated endothelial cells and new blood vessels in tumors. Although numerous results have been reported by the usage of cRGD peptide-based ligands for cancer diagnosis and therapy, the distinct mechanisms, and functions of cRGD-integrin binding to cancer cells are still being investigated. In this study, we evaluated the internalization efficacy of different types of cRGD peptides (monomer, dimer and tetramer form) in integrin αvβ3 overexpressing cancer cells. Western blot and flow cytometric analysis showed U87MG expresses highly integrin αvβ3, whereas CT-26 does not show integrin αvβ3 expression. Cytotoxicity assay indicated that all cRGD peptides (0-200 µM) had at least 70-80% of viability in U87MG cells. Fluorescence images showed cRGD dimer peptides have the highest cellular internalization compare to cRGD monomer and cRGD tetramer peptides. Additionally, transmission electron microscope results clearly visualized the endocytic internalization of integrin αvβ3 receptors and correlated with confocal microscopic results. These results support the rationale for the use of cRGD dimer peptides for imaging, diagnosis, or therapy of integrin αvβ3-rich glioblastoma.

Electrochemistry Characterization of Metal Using Corrosion Inhibitors Containing Amide Functional Group (아미드 작용기를 가진 부식억제제를 사용한 금속의 전기화학적 특성)

  • Park, Keun-Ho
    • Journal of the Korean Applied Science and Technology
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    • v.28 no.1
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    • pp.48-56
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    • 2011
  • In this study, we investigated the C-V diagrams and metal surface related to the electrochemistry characterization of metal(nickel, SUS-304). We determined electrochemical measurement by using cyclic voltammetry with a three-electrode system. A measuring range was reduced from initial potential to -1350mV, continuously oxidized to 1650 mV and measured to the initial point. The scan rate were 50, 100, 150, 200 and 250 mV/s. As a result, the C-V characterization of metal using N,N-dimethylacetamide and N,N-dimethylformamide inhibitors appeared irreversible process caused by the oxidation current from the cyclic voltammogram. After adding organic corrosion inhibitors, adsorption film constituted, and the passive phenomena happened. According to the results by cyclic voltammetry method, it was revealed that the addition of inhibitors containing amide functional group enhances the corrosion resistance properties.

Electrochemistry Characterization of Nickel Using Ethanolamine Compound Additives (에탄올아민화합물 첨가에 대한 니켈의 전기화학적 특성)

  • Park, Keun-Ho
    • Journal of the Korean Applied Science and Technology
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    • v.27 no.4
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    • pp.531-538
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    • 2010
  • The electrochemistry characterization of metal is important in many industrial applications. In this study, we investigated the C-V diagrams related to the electrochemistry characterization of nickel. We determined electrochemical measurement by using cyclic voltammetry with a three electrode system. A measuring range was reduced from initial potential to -1350mV, continuously oxidized to 1650mV and measured to the initial point. The scan rate were 100, 150, 200 and 200mV/s. As a result, the C-V characterization of nickel using ethanolamine and ethylethanolamine inhibitor appeared irreversible process caused by the oxidation current from the cyclic voltammogram. After adding ethanolamine compound additive, adsorption film constituted, and the passive phenomena happened. According to the results by cyclic voltammetry method, it was revealed that the effect of the electrochemistry characterization of nickel depends on ethanolamine structure interaction to adsorption complex.

VIABILITY FOR SEMILINEAR DIFFERENTIAL EQUATIONS OF RETARDED TYPE

  • Dong, Qixiang;Li, Gang
    • Bulletin of the Korean Mathematical Society
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    • v.44 no.4
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    • pp.731-742
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    • 2007
  • Let X be a Banach space, $A:D(A){\subset}X{\rightarrow}X$ the generator of a compact $C_0-semigroup\;S(t):X{\rightarrow}X,\;t{\geq}0$, D a locally closed subset in X, and $f:(a,b){\times}C([-q,0];X){\rightarrow}X$ a function of Caratheodory type. The main result of this paper is that a necessary and sufficient condition in order that D be a viable domain of the semi linear differential equation of retarded type $$u#(t)=Au(t)+f(t,u_t),\;t{\in}[t_0,\;t_0+T],{u_t}_0={\phi}{\in}C([-q,0];X)$$ is the tangency condition $$\limits_{h{\downarrow}0}^{lim\;inf\;h^{-1}d(S(h)v(0)+hf(t,v);D)=0}$$ for almost every $t{\in}(a,b)$ and every $v{\in}C([-q,0];X)\;with\;v(0){\in}D$.

Study on the Suitability of Composite Materials for Enhancement of Automotive Fuel Economy (자동차 연비향상을 위한 복합재료 적용 타당성에 관한 연구)

  • Ju, Yeon Jin;Kwon, Young-Chul;Choi, Heung Soap
    • Composites Research
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    • v.32 no.5
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    • pp.284-289
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    • 2019
  • In the present paper, the dynamic force-moment equilibrium equations, driving power and energy equations are analyzed to formulate the equation for fuel economy(km/liter) equivalent to the driving distance (km) divided by the fuel volume (liter) of the vehicle, a selected model of gasoline powered KIA K3 (1.6v). In addition, the effects of the dynamic parameters such as speed of vehicle (V), vehicle total weight(M), rolling resistance ($C_r$) between tires and road surface, inclined angle of road (${\theta}$), as well as the aerodynamic parameters such as drag coefficient ($C_d$) of vehicle, air density(${\rho}$), cross-sectional area (A) of vehicle, wind speed ($V_w$) have been analyzed. And the possibility of alternative materials such as lightweight metal alloys, fiber reinforced plastic composite materials to replace the conventional steel and casting iron materials and to reduce the weight of the vehicle has been investigated by Ashby's material index method. Through studies, the following results were obtained. The most influencing parameters on the fuel economy at high speed zone (100 km/h) were V, the aerodynamic parameters such as $C_d$, A, ${\rho}$, and $C_r$ and M. While at low speed zone (60 km/h), they are, in magnitude order, dynamic parameters such as V, M, $C_r$ and aerodynamic ones such as $C_d$, A, and ${\rho}$, respectively.

Interpretation and Education of topic phrase shown on the Analects of Confucius (1) - Based on the examples of the 'DO' eventuality meaning phrase (논어 화제구의 해석과 교육(1) - '활동(DO)' 사건의미 표시구의 예를 중심으로)

  • 김종호
    • Journal of Sinology and China Studies
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    • v.79
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    • pp.245-275
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    • 2019
  • The Chinese language is a topic-prominent language and the ancient form of the language is not an exception. This literature examines the theta roles and cases of the arguments by setting sentence structures regarding 'TopP', which marks the eventuality meaning of 'DO', from the Analects of Confucius. Summary of the analysis is as follows: 1. Like the contemporary Chinese, ancient Chinese has two topic types; one is a base-generated topic(so called dangling topic) and the other is a topic generated by the interior movement in the TP. 2. The sentence structure of TopP from the Analects of Confucius that marks the eventuality meaning of 'DO' can be divided into seven categories which are: T+S+V+O', 'T+ES+V+EO', 'T+ES+V+EO', 'T+S+V+EC', 'T+ES+V+C', 'T+ES+V+O+C', 'T+S+V+EO+C'. 3. The predicate(V-v) of TopP from the Analects of Confucius that marks the eventuality meaning of 'DO' has a meaning characteristics of [+ will] and [+ progressive]. 4. The subject of TopP from the Analects of Confucius that marks the eventuality meaning of 'DO' is assigned a thematic role of an , and the object is assigned a thematic role of a . 5. The complement of TopP from the Analects of Confucius that marks the eventuality meaning of 'DO' is composed of overt preposition head and its complements, which receives diverse thematic roles from the preposition. However, it does not have a direct selective relationship but an indirect relationship with the main verb of the sentence. 6. Every argument, which is the subject, object, complement, and adverb, of TopP from the Analects of Confucius that marks the eventuality meaning of 'DO' can theoretically be moved in front of the subject and be topicalized. 7. The topic phrase from the Analects of Confucius that marks the eventuality meaning of 'DO' is derived in the order of predicate(V-v), object, complement, adjunct, subject, and topic, but when interpreting it in Korean it is in inverse order, which is in the order of topic, subject, adjunct, complement, object and predicate(V-v).

A Characteristics of Heat Affected Zones in Weld Repair for a Damaged CrMoV Turbine Rotor Steel (손상된 CrMoV 터빈로터강의 보수용접에서 후열처리 온도에 따른 열영향부의 특성)

  • 김광수;오영근;안병국
    • Journal of Welding and Joining
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    • v.14 no.4
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    • pp.89-98
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    • 1996
  • This study was performed to establish the characteristics of the heat affected zones from view point of the repair weldability for a damaged CrMoV steam turbine rotor steel. Characterization of the heat affected zones of the weldment was conducted with respect to various of postweld heat treatment temperatures, $566^{\circ}C$, $621^{\circ}C$ and $677^{\circ}C$. The evaluations of the heat affected zones were carried out in terms of microstructural characterization, microhardness measurements, Charpy v-notch impact, tensile and stress-rupture tests. The results indicated that the effect of the postweld heat treatment at $677^{\circ}C$ exhibited the favorable microstructure and mechanical properties for the stability of the heat affected zones. While the heat affected zone of the weldment, produced without postweld heat treatment, displayed the inferior toughness and microstructure indicating localized carbide precipitations on the grain boundary. It was also indicated that the stability of the heat affected zones were deteriorated by the formation of the cavitation on the grain boundaries.

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