• 제목/요약/키워드: Activated material

검색결과 746건 처리시간 0.033초

탄소 전극 형상 변화에 따른 전기화학 커패시터 특성 향상 (Improvement of Electrochemical Characteristics by Changing Morphologies of Carbon Electrode)

  • 민형섭;김상식;정덕수;최원국;오영제;이전국
    • 한국재료학회지
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    • 제19권10호
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    • pp.544-549
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    • 2009
  • Activated carbon (AC) with very large surface area has high capacitance per weight. However, such activation methods tend to suffer from low yields, below 50%, and are low in electrode density and capacitance per volume. Carbon NanoFibers (CNFs) had high surface area polarizability, high electrical conductivity and chemical stability, as well as extremely high mechanical strength and modulus, which make them an important material for electrochemical capacitors. The electrochemical properties of immobilized CNF electrodes were studied for use as in electrical double layer capacitor (EDLC) applications. Immobilized CNFs on Ni foam grown by thermal chemical vapor deposition (CVD) were successfully fabricated. CNFs had a uniform diameter range from 50 to 60 nm. Surface area was 56 m$^2$/g. CNF electrodes were compared with AC and multi wall carbon nanotube (MWNT) electrodes. The electrochemical performance of the various electrodes was examined with aqueous electrolyte of 2M KOH. Equivalent series resistance (ESR) of the CNF electrodes was lower than that of AC and MWNT electrodes. The specific capacitance of 47.5 F/g of the CNF electrodes was achieved with discharge current density of 1 mA/cm$^2$.

체외순환을 이용한 심장수술시 혈청 Interleukin-6, Tumor Necrosis Factor-$\alpha$와 Troponin-T의 시간대별 변화 (Sequential changes of Interleukin-6, Tumor Necrosis Factor-$\alpha$, and Troponin-T During Open Heart Surgery with Cardiopulmonary Bypass)

  • 류지윤;최석철;곽기오;최국렬;김송명;조광현
    • Journal of Chest Surgery
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    • 제32권11호
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    • pp.971-977
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    • 1999
  • Background: Immunologic and inflammatory responses of cardiopulmonary bypass(CPB) influence postoperative mortality and morbidity with multiple organ injury. It has been reported that ischemia/reperfusion induced-myocardial injury during CPB is causative of release of inflammatory cytokines such as interleukin-6(IL-6) and tumor necrosis factor-$\alpha$ (TNF-$\alpha$). The purpose of this study was to detect the time course of the activated cytokine and troponin-T(TnT), and to examine the correlation between such parameters during CPB. Material and Method: The serial samples were collected from arterial blood via radial arterial catheter in 23 patients who are underwent open heart surgery (OHS) with CPB, the IL-6, TNF-$\alpha$ and TnT were checked. Result: \circled1 IL-6, TNF$\alpha$- and TnT concentration increased significantly during CPB with a peaking level of CPB-off (p 0.05). \circled2 IL-6 had highly positive correlation with aortic cross clamping time and total bypass time(r=0.80, 0.78; p 0.05, respectively). \circled3 There was no correlation among IL-6, TNF-$\alpha$ and TnT. Conclusion: In conclusion, these data showed that elevated production of serum IL-6 during CPB was attributable to ischemia/reperfusion induced-myocardial damage. IL-6 will become a new and sensitive biological marker in assessment of myocardial damage during OHS with CPB. However, further studies will be needed to apply IL-6 in more patient population.

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Anti-inflammatory Activity of Stevia rebaudiana in LPS-induced RAW 264.7 Cells

  • Jeong, Il-Yun;Lee, Hyo-Jung;Jin, Chang-Hyun;Park, Yong-Dae;Choi, Dae-Seong;Kang, Min-Ah
    • Preventive Nutrition and Food Science
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    • 제15권1호
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    • pp.14-18
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    • 2010
  • Stevia rebaudiana (SR) is an herb used traditionally as a sweetener in Paraguay and Brazil, whose use is spreading to other countries, such as Japan, Korea and China. In addition to its low calorie sweet taste, SR appears to have other beneficial properties, such as hypotensive capabilities and inflammation reduction. To identify the bioactive natural constituents exerting anti-inflammatory activities, we examined the EtOAc fraction of SR. In the inflammatory mediator inhibitory assay from lipopolysaccharide (LPS)-activated macrophages, the EtOAc fraction significantly, and dose dependently, inhibited the enhanced production of nitric oxide (NO) and inducible nitric oxide synthase (iNOS) expression. We also found that treatment of cells with the EtOAc fraction significantly inhibited LPS-stimulated nuclear factor-${\kappa}B$ (NF-${\kappa}B$) reporter gene expression. Such inhibition of NF-${\kappa}B$ was closely associated with the inhibition of interleukin-6 (IL-6) and the monocyte chemoattractant protein-1 (MCP-1). Therefore, we suggest that SR has the potential for development as a functional food for the treatment of immune diseases, such as rheumatoid arthritis and lupus.

활성표피를 통한 빛의 유입에 관한 연구 - 헤르조그 & 드 뫼롱의 작품을 중심으로 - (A Study on the inflow of Sunlight through the Active Building Skin - Focusing on Works of Herzog & de Meuron -)

  • 나하나;박부미
    • 한국실내디자인학회논문집
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    • 제26권4호
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    • pp.30-41
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    • 2017
  • Sunlight is perceived by human beings first through the epidermis to space, and is a non - material medium that provides physical awareness of space, diversified expression of spaces, and plenty experience. The purpose of this study is to investigate the characteristics of active building skin based on the inflow of natural light required by humans, looked through among the works of Jacques Herzog & Pierre de Meuron, which show the characteristics of active building skin, TEA(Tenerife Espacio de las Artes, 2008), Messe Basel New Hall (2013) and Elbphilharmonie (2016). First, the interaction between Sunlight and space is divided into spatial characteristics and sensitivities according to their concepts, properties, and characteristics. The characteristics of active skin by light are classified into a physical approach and a constructive approach. Second, (El Croquis 152/153) and analyzed the images, detail drawings, and elevations, and simulated them in 3D to express the relationship between light and active building skin. Third, the changes of light intensity, light color, and distribution of light according to the time of light entering and the skin are determined from 6:00 am to 6:00 pm. Fourth, the images taken from January 30th to February 7th, 2017 on the site were compared with the computer simulated images, and the relationship between active skin and light was compared. This study is to recognize the existence and necessity of light required for human being through the activated epidermis differentiated from the limited or closed epidermis focused on information transmission, I would like to emphasize that I would like to take a step closer to the necessity and possibility of new attempts and developments so that I can feel the various experiential spaces by.

LPS로 유도된 RAW 264.7 대식세포에 대한 미역(Undaria pinnatifida) Ethyl Acetate 분획물의 항염증 효과 (Anti-Inflammatory Effect of Ethyl Acetate Fraction Isolated from Undaria pinnatifida on Lipopolysaccharides-Stimulated RAW 264.7 Cells)

  • 최민우;김재일
    • 한국수산과학회지
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    • 제46권4호
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    • pp.384-392
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    • 2013
  • An ethanolic extract of Undaria pinnatifida was fractionated using several solvents. Of the fractions, the ethyl acetate fraction had the greatest inhibitory effect on lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW 264.7 macrophage cells. Using this fraction (U. pinnatifida ethyl acetate extract, UPE), we investigated the molecular mechanism underlying its inhibitory effect on LPS-stimulated RAW 264.7 cells. Pretreatment of the cells with up to $100{\mu}g/mL$ UPE significantly inhibited NO production and inducible nitric oxide synthase (iNOS) expression, in a dose-dependent manner. Similarly, UPE treatment markedly reduced the production of pro-inflammatory cytokines, such as interleukin (IL)-1, IL-6 and tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), while it strongly suppressed the nuclear translocation of nuclear factor-kappa B (NF-${\kappa}B$) by preventing proteolytic degradation of inhibitor of nuclear factor ${\kappa}B$ $(I{\kappa}B)-{\alpha}$. Moreover, UPE treatment significantly reduced the phosphorylation of phosphatidylinositol 3-kinase (PI3K)/Akt and mitogen-activated protein kinase (MAPK) in LPS-stimulated cells. These results indicate that UPE contains anti-inflammatory compounds and suggest that it might be used as a functional food material that assists in prevention of inflammatory diseases.

Mn4+ 이온 활성 K2TiF6 불화물 적색형광체의 합성과 발광특성 (Synthesis of K2TiF6:Mn4+ Red Phosphors by a Simple Method and Their Photoluminescence Properties)

  • 김연;우미혜;최성호;심광보;정하균
    • 한국재료학회지
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    • 제26권9호
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    • pp.504-511
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    • 2016
  • To prepare $Mn^{4+}$-activated $K_2TiF_6$ phosphor, a precipitation method without using hydrofluoric acid (HF) was designed. In the synthetic reaction, to prevent the decomposition of $K_2MnF_6$, which is used as a source of $Mn^{4+}$ activator, $NH_5F_2$ solution was adopted in place of the HF solution. Single phase $K_2TiF_6$:$Mn^{4+}$ phosphors were successfully synthesized through the designed reaction at room temperature. To acquire high luminance of the phosphor, the reaction conditions such as the type and concentration of the reactants were optimized. Also, the optimum content of $Mn^{4+}$ activator was evaluator based on the emission intensity. Photoluminescence properties such as excitation and emission spectrum, decay curve, and temperature dependence of PL intensity were investigated. In order to examine the applicability of this material to a white LED, the electroluminescence property of a pc-WLED fabricated by combining the $K_2TiF_6$:$Mn^{4+}$ phosphor with a 450 nm blue-LED chip was measured.

The improvement effect of anti-inflammation of Aronia extract that fermented by Lactic acid bacteria isolated from the fermented seafoods

  • Lim, Jeong-Muk;Choi, Ui-Lim;Lee, Jeong-Ho;Moon, Kwang Hyun;Kim, Dae Geun;Jeong, Kyung Ok;Im, So Yeon;Oh, Byung-Taek
    • 한국자원식물학회:학술대회논문집
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    • 한국자원식물학회 2018년도 추계학술대회
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    • pp.111-111
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    • 2018
  • Aronia (black chokeberry), a species of berries is source to a very large number of bioactive compounds like polyphenols, flavonoids, anthocyanins, and tannins in comparison to any other species. Owing to its antioxidant, anti-carcinogenic, anti-aging and anti-inflammatory properties. Fermentation- a bioconversion process exploiting the biological metabolic reaction of micro-organisms, has several benefits like improving the efficacy and safety of physiologically active substances, generation of new functional material, improving the adsorption rate and many others. Antigens like pathogens, food, pollen etc., generate a protective immune response in body tissues, and the process be referred to as inflammation. However, this when excessive results in a condition referred to as refractory inflammatory disease, whose incidence is increasing in the recent times, especially amongst children. The current study intended to assess the anti-oxidant activity, presence of polyphenols and anti-inflammatory efficacy of Aronia extract fermented by Lactic acid bacteria isolated from fermented sea foods. Aronia fruits collected from Sunchang, Chonbuk were lyophilized for fermentation. So as to maximise the efficacy of the fermented Aronia extract, the quantitative effects of lactic acid bacteria species, composition of extraction solution, influence of temperature and time on antioxidant activity and total polyphenol contents were investigated using an experimental design. Anti-inflammatory activity was evaluated on NO and cytokine ($TNF-{\alpha}$, IL-6) production in LPS activated Raw 264.7 cells. Results indicated that antioxidant effect and total polyphenol contents were best improved in extract of Aronia fermented by P. pentosaceus. In addition, NO and cytokine ($TNF-{\alpha}$, IL-6) levels were decreased significantly after fermentation. Thus, it was found that the anti-inflammatory activity of Aronia greatly increased after fermentation process using P. pentosaceus.

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三元丹 에탄올 추출물이 비만유도인자에 미치는 영향 (Effect of the Samwondan Ethanol Extract on Obesity Inducer)

  • 강경수;이해진;심부용;박지원;최학주;김동희
    • 대한본초학회지
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    • 제30권4호
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    • pp.21-27
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    • 2015
  • Objectives : In this study, we investigated the biological activities such as anti-obesity using Samwondan ethanol extract (SWD). SWD is a complex with Salicornia herbacea Linnaeus, Saururus chinensis Baill and Houttuynia cordata Thunberg as the main raw material.Methods : The SWD was extracted 80% ethanol. 3T3-L1 preadipocytes were induced adipogenesis by differentiation media with SWD at 1 μg/mL, 10 μg/mL, and 100 μg/mL. Effect of SWD performed using MTT assay, oil red O staining (observation by microscope), and reverse transcription polymerase chain reaction. Also we measured production of triglyceride (TG), fatty acid, and acetyl-CoA carboxylase (ACC).Results : Non-cytotoxicity was in all test group from range of 1 μg/mL to 100 μg/mL on pre-adipocyte. The droplet and production of lipid were decreased significantly by the SWD. And TG was decreased by approximately 89%, 85% and 82%, upon the SWD treatment at concentration of 1 μg/mL, 10 μg/mL, and 100 μg/mL. Moreover, the SWD showed inhibitory effects on the expression of the C/EBP (CCAAT/enhaner binding protein)β, C/EBPα, and peroxisome proliferator-activated receptorγgenes in adipocytes. The SWD at 100 μg/mL concentration showed inhibitory effect on fatty acid production by 79%. Also ACC production were decreased dose-dependently.Conclusions : From the results above, we concluded that the SWD indicated significantly anti-obesity effects.

WBI에서의 XML 다중인증 시스템 (Multiplex Certification System Using XML For WBI)

  • 신영준;이동휘;김정재;김귀남
    • 한국사이버테러정보전학회:학술대회논문집
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    • 한국사이버테러정보전학회 2004년도 제1회 춘계학술발표대회
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    • pp.297-302
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    • 2004
  • 정보통시 기술의 비약적인 발전으로 인해 인터넷은 필수 불가결한 도구가 되고 있다. 이러한 정보화 시대의 요구에 대한 교육적 대응은 학습자중심의 교육이며, 정보통신 기술을 기반으로 한 원격 교육이다 WBI(Web Based Instruction)는 웹을 매체로 활용하여 원거리에 있는 학습자를 교육시키는 형태로서 교수자와 학습자간 상호작용을 가능하게 하고, 다양한 형태의 학습 자료를 제공하며 공간적 제약을 극복할 수 있다는 장점이 있다. 그와 더불어 차세대 웹 표준문서 포맷으로 부상되고 있는 XML(extensible Markup Language)을 사용한 규격에 대한 국내외적인 표준화 작업 또한 가속화되고 있으며 최근 XML 보안에 대한 연구가 활성화 되었다. 또한 XML 전자서명은 XML문서를 이용하는 여러 분야에 사용되어 전자서명 시스템간의 상호 연동성을 높일 수 있다. 그리고 앞으로 웹상에서 사용되어지는 공인인증서에 대한 소비자와 관리자의 금전적인 면에서 또한 사용자의 ID PW로 인한 보안적 측면을 고려한 방법으로 XML 전자서명 기법을 이용한 다중인 방식을 추가 시키는 방법이다. 이에 본 논문에서는 시스템 내에서 XML 전자서명 기법을 이용한 다중인증 원격교육 에이전트 시스템을 제안 하였다.

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강화형 strip crown의 사용 (GLASS FIBER REINFORCED STRIP CROWN IN PRIMARY TEETH)

  • 김대업
    • 대한소아치과학회지
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    • 제32권1호
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    • pp.132-135
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    • 2005
  • 본 연구의 목적은 유전치 심미수복의 새로운 방법으로 glass fiber를 이용한 강화형 strip crown의 사용을 제시하고자 하는 것이다. Strip crown의 제작을 위하여 celluloid crown form(3M, USA)과 복합레진은 Z100(P shade, 3M, USA)을, 유동성 복합레진은 Aeliteflo(Bisco Inc., USA)를 사용하였다. 상아질 결합제는 Clearfil SE Bond(Kuraray Medical Inc., Japan)를 사용하였고 강화를 위하여 그물형 glass fiber(TESCERA Fiber Mesh, Bisco Inc, USA)를 사용하였다. 적절한 크기의 celluloid crown form을 성형하여 삭제된 치아에 시적한 후 레진 접착제와 유동성 복합레진으로 처리한 그물형 glass fiber를 설측 내면에 삽입하고 광중합하였다. 잔여 공간에 복합레진을 채우고 치아에 끼운 다음 광중합하였다. 복합레진의 심미성은 유지하면서 glass fiber로부터 기계적 장점을 얻을 수 있을 것으로 사료된다. 새로운 강화형 strip crown의 물성에 대한 후속연구가 필요하다.

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