• 제목/요약/키워드: pretreatments

검색결과 275건 처리시간 0.035초

Pinning retrofit technique in masonry with application of polymer-cement pastes as bonding agents

  • Shrestha, Kshitij C.;Pareek, Sanjay;Suzuki, Yusuke;Araki, Yoshikazu
    • Earthquakes and Structures
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    • 제5권4호
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    • pp.477-497
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    • 2013
  • This paper reports extensive experimental study done to compare workability and bond strength of five different types of polymer-based bonding agents for reinforcing bars in pinning retrofit. In pinning retrofit, steel pins of 6 to 10 mm diameters are inserted into holes drilled diagonally from mortar joints. This technique is superior to other techniques especially in retrofitting historic masonry constructions because it does not change the appearance of constructions. With an ordinary cement paste as bonding agent, it is very difficult to insert reinforcing bars at larger open times due to poor workability and very thin clearance available. Here, open time represents the time interval between the injection of bonding agent and the insertion of reinforcing bars. Use of polymer-cement paste (PCP), as bonding agent, is proposed in this study, with investigation on workability and bond strengths of various PCPs in brick masonry, at open times up to 10 minutes, which is unavoidable in practice. Corresponding nonlinear finite element models are developed to simulate the experimental observations. From the experimental and analytical study, the Styrene-Butadiene Rubber polymer-cement paste (SBR-PCP) with prior pretreatments of drilled holes showed strong bond with minimum strength variation at larger open times.

계지약침(桂枝藥鍼)이 Type 1 Hypersensitivity에 미치는 영향 (Effect of Cinnamomi Ramulus Herbal Acupuncture on the Type 1 Hypersensitivity)

  • 김동훈;송춘호
    • Korean Journal of Acupuncture
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    • 제26권1호
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    • pp.125-137
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    • 2009
  • Objectives : We studied anti-allergic effects of Cinnamomi Ramulus(CR) herbal acupuncture and Cinnamomi Ramulus extract. Methods : In vivo, animals were herbal-acupunctured with CR at both ST36s three times for 5 days. Then, we induced active systemic anaphylatic shock using compound 48/80 in ICR mice, and passive cutaneous anaphylaxis using anti-DNP IgE in Sprague Dawley rat. In vitro, we measured cell viability, ${\beta}$ -hexosaminidase release and the expressions of IL-4, TNF-${\alpha}$ and COX-2 mRNA in RBL-2H3 cells after treatment of various concentrations of CR extract. Results : In vivo, CR herbal acupuncture pretreatments at both ST36s inhibited compound 48/80-induced active systemic anaphylatic shock. Passive cutaneous anaphylaxis was inhibited by CR herbal acupuncture pretreatments at both ST36s and optional points. In vitro, CR extract treatments did not affect on cell viability and inhibited ${\beta}$-hexosaminidase release. CR extract treatments also decreased the expressions of IL-4, TNF-${\alpha}$ and COX-2 mRNA in RBL-2H3 cells. Conclusions : These results suggest that CR herbal acupuncture and CR extract should be beneficial in the inhibition of allergic inflammatory response.

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Progression of Apoptotic Cells by Pretreatment of Proteinase K

  • Joo, Kyeng-Woong
    • 대한의생명과학회지
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    • 제8권3호
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    • pp.161-165
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    • 2002
  • Apoptosis can be difficult to detect in routine histological sections. Since extensive DNA fragmentation is an important characteristic of this process, visualization of DNA breaks could greatly facilitate the identification of apoptotic cells. Several techniques for the qualitative and quantitative detection of this process have been established; recently, an in situ nick end-labelling technique based on the detection of DNA fragmentation, which is a molecular characteristic of apoptotic cell death, was described. Applying this method to paraffin sections of rat tissues, sensitivity was observed to be inconsistently low with regard to the expected number of apoptotic cells. I describe a new modified method for formalin-fixed, paraffin-embedded tissue sections, pretense pretreatment to permeate the tissue sections that involves an TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling) is acknowledged as a method of choice in the rapid identification and quantification of the apoptotic cell fraction in paraffin tissue preparations. TUNEL was performed without apoptosis and with apopotosis samples to each of the three concentrations of proteinase K (10, 25, 40 mg/ml) pretreatments. In this study, I show that chemical pretreatments of the tissue sections in proteinase K (25 mg/ml for 15 min at room temperature) considerably enhances the sensitivity of this nick end labelling technique.

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목과(木瓜) 추출물이 항알레르기 및 항산화 작용에 미치는 영향 (The Antiallergic and Antioxidative Effects of Chaenomeles Sinensis (CS) in RBL 2H3 Cells)

  • 이승연
    • 대한한방소아과학회지
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    • 제24권2호
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    • pp.126-136
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    • 2010
  • Objectives The purpose of this study was to investigate the antiallergic and antioxidative effects of Chaenomeles Sinensis (CS). Methods CS pretreatments inhibited anti-DNP IgE in RBL-2H3 mast cells for an hour. we measured cell viability, $\beta$-hexosaminidase release, IL-4, TNF-$\alpha$ secretion, and IL-4, TNF-$\alpha$ mRNA expression CS pretreatments inhibited DNP-HSA($10\;{\mu}g/ml$) for ten minutes, we measured Dicholrodihydrofluorescein(DCF) and DPPH radical-scavenging activity in 0.5 mM 1,1-diphenyl-2-picrydrazyl(DPPH) radical solution, 0.1ml, 99% ethanol 0.8ml, and CS 0.1 ml mixed solution. Results 0, 1, 2, 3, 4, 5 mg/ml CS treatments were not affect on cell viability and inhibited b-hexosaminidase release, IL-4, TNF-$\alpha$ secretion, CS treatments also decreased IL-4, TNF-$\alpha$ mRNA expression in RBL-2H3 cells. CS treatments inhibited reactive oxygen species(ROS) and DPPH radical-scavenging activity. Conclusions These results suggest that CS may be useful for the prevention or treatment of allergic disease.

Distribution of Phlorotannins in the Brown Alga Ecklonia cava and Comparison of Pretreatments for Extraction

  • Chowdhury, Muhammad Tanvir Hossain;Bangoura, Issa;Kang, Ji-Young;Park, Nam-Gyu;Ahn, Dong-Hyun;Hong, Yong-Ki
    • Fisheries and Aquatic Sciences
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    • 제14권3호
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    • pp.198-204
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    • 2011
  • The brown seaweed Ecklonia cava is known to be a rich source of phlorotannins that have diverse biological activities. Among the phlorotannins in E. cava, concentrations of dieckol and phlorofucofuroeckol-A, which were identified as major active components, were determined in different parts of the tissue. We compared the efficacy of different pretreatments for their extraction. A high-performance liquid chromatography (HPLC) method to determine phlorotannin concentrations showed good accuracy (92.64 and 94.02%, respectively), precision (3.92 and 3.94%, respectively), and linearity (r>0.996). Mature thalli contained 1.5-fold more dieckol (1.82 mg/g-dry tissue) than young thalli. In the tissues of E. cava, blade tissue contained more phlorotannins than the stipe or holdfast. Among differently dried thalli, approximately 90% or more dieckol and phlorofucofuroeckol-A were extracted from shadow-dried tissue as compared with lyophilized tissue. In sun-dried and oven-dried thalli, approximately 60% of the phlorotannins were extracted. Thalli washed with fresh water, boiled thalli, and steamed thalli showed reduced extraction of the compounds.

Chongmyungtang Attenuates Kainic Acid-induced Seizure and Mortal Effect in the Mouse

  • Jang, Kyung-Jin;Lee, Kyou-Heung;Kim, Sang-Lin;Park, Dong-Young;Park, Beom-Kyu;Im, Doo-Hyung;Cho, Yong-Joon;Jhoo, Wang-Kee;Kim, Hyoung-Chun
    • Archives of Pharmacal Research
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    • 제20권4호
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    • pp.375-378
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    • 1997
  • The Chongmyungtang (CMT; the combination of Acorus gramineus, polygala tenuifolia and Poria cocos) has been recognized to possess the preventive effect against several neurologic disorders in human. In this study, we examined the effect of CMT on the three parameters associated with kainic acid (KA)-induced neurotoxicities; seizure/mortality, increased fos-related antigen (FRA) and glial fibrillary acidic protein (GFAP) expression. KA induced vigorous convulsions lasting 4-6 hr. Pretreatments with CMT before KA injection significantly reduced the seizure intensity as well as the mortality. CMT pretreatments also attenuated the KA-induced increase in FRA/GFAP expression in the hippocampus. These results suggest that CMT has a neuroprotective effect against KA-induced neurotoxicities.

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전처리가 CVD 텅스텐의 핵 생성에 미치는 영향 (Effects of various Pretreatments on the Nucleation of CVD Tungsten)

  • 김의송;이종무;이종길
    • 한국재료학회지
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    • 제2권6호
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    • pp.443-451
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    • 1992
  • 반응성 스팟터법에 의하여 형성된 TiN막 표면상에 CVD 텅스텐막을 증착할 때 여러가지 전처리 실시에 따른 텅스덴의 핵 생성 양상의 변화를 비교 조사하였다. 먼저 Ar rf 스팟터에칭 전처리는 에칭 두께가 200A 이상일 때에는 잠복기와 증착속도를 증가시킨다. Ar 이온주입 전처리는 잠복기를 증가시켜 텅스텐의 핵 생성에는 불리한 효과를 나타내는 반면, 증착속도는 증가시킨다. 또한 Si$H_4$flushing 전처리는 TiN막 표면에서의 Si의 흡착을 용이하게 함으로써 잠복기를 약간 감소시키는 효과를 나타낸다.

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생물학적 수소생산 공정 개발을 위한 오니 슬러지 전처리에 대한 연구 (A Study on the Pretreatment of Activated Sludge for Bio-hydrogen Production Process)

  • 박대원;김동건;김지성;박호일
    • 한국수소및신에너지학회논문집
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    • 제15권3호
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    • pp.187-193
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    • 2004
  • In this study, Anaerobic sewage sludge in a batch reactor operation at $35^\circ{C}$ was used as the seed to investigate the effect of pretreatments of waste activated sludge and to evaluate its hydrogen production potential by anaerobic fermentation. Various pretreatments including physical, chemical and biological means were conducted to utilize for substrate. As a result, SCODcr of alkali and mechanical treatment was 15 and 12 times enhanced, compared with a supernatant of activated sludge. And SCODcr was 2 time increase after re-treatment with biological hydrolysis. Those were shown that sequential hybridized treatment of sludge by chemical & biological methods to conform hydrogen production potential in bath experiments. When buffer solution was added to the activated sludge, hydrogen production potential increased as compare with no addition. Combination of alkali and mechanical treatment was higher in hydrogen production potential than other treatments.