• 제목/요약/키워드: cross-linking

검색결과 664건 처리시간 0.029초

아크릴계 점착제와 초박형 웨이퍼소재와의 점착특성 - 아크릴 중합체의 측쇄의 영향 - (Adhesion Characteristics of Acrylic Pressure Sensitive Adhesives on Thin Wafer Materials - Effect of Acrylic Copolymer Side Chain -)

  • 유종민;남영희;이승현;김형일;임동혁;김현중;김경만
    • 접착 및 계면
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    • 제10권3호
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    • pp.134-140
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    • 2009
  • 분자설계를 통하여 측쇄를 변화시킨 아크릴공중합체를 합성하여 아크릴공중합체 점착제와 초박형웨이퍼와의 젖음성 및 점착물성을 조사하였다. 선형 아크릴공중합체를 에폭시계 Tetra-DX 가교제와 반응시켜 3차원 망상구조를 형성하고 가교의 영향을 조사하였다. 계면상호작용보다는 아크릴공중합체의 측쇄변화가 젖음성에 더 큰 영향을 미쳤다. 가교도가 증가할수록 probe tack, peel strength가 감소하는 경향을 나타냈다. 가교에 의해 SAFT 내열성이 증가하였지만 가교제의 함량이 증가하면 오히려 SAFT 내열성이 감소하였다.

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벌개미취 에탄올추출물의 STZ-유도 당뇨 모델에서의 최종당화산물의 생성 및 교차결합에 미치는 효과 (Inhibitory Effects of the EtOH Extract of Aster koraiensis on AGEs formation in STZ-induced diabetic rats and AGEs-induced Protein Cross-linking in vitro)

  • 김정현;김찬식;김진숙
    • 생약학회지
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    • 제47권4호
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    • pp.312-318
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    • 2016
  • Advanced glycation end products (AGEs) such as $N^{\varepsilon}$-(carboxy-methyl)lysine (CML) have been implicated in the development of diabetic nephropathy. The aim of this study was to investigate the inhibitory effects of ethanolic extract of Aster koraiensis (AKE) on AGEs formation and AGEs-collagen cross-linking in vitro and CMLs formation in streptozotocin (STZ)-induced diabetic rats. AKE significantly inhibited AGEs formation ($IC_{50}$ value of $18.74{\mu}g/mL$) and AGEs-collagen cross-linking ($IC_{50}$ value of 0.274 mg/mL) in vitro than the well-known glycation inhibitor aminoguanidine ($IC_{50}$ value of $72.12{\mu}g/mL$ and 1.99 mg/mL, respectively). AKE (100 mg/kg per day) was given to diabetic rats for 9 weeks. In STZ-induced diabetic rats, severe hyperglycemia was developed, and urinary CMLs and plasma CMLs were markedly increased. Immunohistochemical stain revealed that CMLs were accumulated within renal glomerulus in STZ-induced diabetic rats. However, AKE significantly reduced urinary CMLs and plasma CMLs in diabetic rats. CMLs accumulation was inhibited by AKE treatment in the renal glomerulus. These results suggest that AKE had an inhibitory effect of AGE accumulation in the glomeruli of diabetic rat and could be an inhibitor of AGE-induced protein cross-linking. The oral administration of AKE may significantly help to prevent the progression of diabetic nephropathy in patients with diabetes.

옥수수 전분유의 Annealing 조건이 인산가교 저항 전분의 형성에 미치는 영향 (Effects of Annealing Conditions of Corn Starch Slurry on the Formation of Phosphorylated Cross-linked Resistant Starch)

  • 배천호;박희동
    • 한국식품저장유통학회지
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    • 제19권2호
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    • pp.216-222
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    • 2012
  • 옥수수 전분의 인산화 가교반응에 의한 RS4 제조 시 최적 annealing 조건을 검토하였다. 전분유에 NaOH를 0.9%, 1.2%, 1.5%/st.ds의 농도가 되게 첨가하고 복합인산염(STMP/STPP 혼합)을 이용하여 인산화 가교반응 할 경우 NaOH 농도가 높을수록 반응 초기에 RS 함량이 빠르게 증가되었으나 NaOH 농도에 상관없이 반응 12시간 후에는 비슷한 RS 함량을 나타내었다. 전분유의 Annealing 처리는 인산화 가교반응 전에 실시하였다. 전분유를 pH 2-10, 온도 $40-60^{\circ}C$, 0-14시간으로 처리한 후 인산화 가교반응을 하였다. Annealing 처리시 pH가 낮을수록 RS 함량이 높아지는 결과를 보였으며 pH 2에서 annealing 온도 $50^{\circ}C$, 2시간 annealing에서 최고의 RS 함량을 나타내었다. 따라서 최적 인산화 가교반응 조건은 먼저 pH 2.0, $50^{\circ}C$에서 2시간 annealing 처리를 한 후 황산나트륨 농도 10%/st.ds, NaOH 농도 1.2%/st.ds 조건에서 12시간 인산화 가교반응을 행하는 것으로 생각된다. RS 함량은 인산염 투입량이 증가함에 따라 직선적으로 증가하였다. 본 연구결과에 의한 최적조건을 활용하여 복합인산염 10%/st.ds의 농도로 RS4를 제조한 결과 RS 함량은 72.3% 였으며 인의 함량은 0.36%/st.ds로 한국 식품첨가물 공전에 적합하여 식품용 소재로 활용이 가능할 것으로 사료된다.

Formation of Cross-Linked Products of The Reaction Center D1 Protein in Photosystem II under Light Stress

  • Uchida, Suguru;Kato, Yoji;Yamamoto, Yasusi
    • Journal of Photoscience
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    • 제9권2호
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    • pp.382-384
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    • 2002
  • When illuminated with strong visible light, the reaction center Dl protein of photo system II is photodamage and degraded. Reactive oxygen species and endogenous cationic radicals generated by photochemical reactions are the cause of the damage to the Dl protein. Recently we found that the photodamaged Dl protein cross-links with the surrounding polypeptides such as D2 and CP43 in photosystem II. As the cross-linking reaction is dependent on the presence of oxygen, reactive oxygen species are suggested to be involved. Among the reactive oxygen species examined, ? OH was most effective in the formation of the cross-linked products. These results indicate that the cross-linking is mostly due to ? OH generated at photosystem II. The cross-linking site of the Dl protein is not known. As several tyrosine residues exist at the D­E loop of the Dl protein, there is a possibility that di-Tyr is formed between the D­E loop of the Dl protein and surrounding polypeptides during the strong illumination. Therefore, we examined the formation of di-Tyr using the monoclonal antibody against di-Tyr under excess illumination of the photosystem II membranes. The results obtained here suggest that no di-Tyr is formed during the excess illumination of photosystem II.

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WEHI-231 cells are defective in the ligand-induced internalization of B cell antigen receptor

  • Yoon, Sang Soon;Kim, Tae Jin
    • IMMUNE NETWORK
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    • 제1권3호
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    • pp.196-202
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    • 2001
  • Backgorund: WEHI-231 B cell line is a representative model for $IgM^+$ mature B cells. To understand the signaling differences between mature and immature B cells, we compared the responsiveness of WEHI-231 and Bal 17 B cell lines to BCR cross-linking. Methods: The extents of tyrosine phosphorylation, ligand-induced internalization, and activation-induced cell death upon BCR cross-linking were compared in two cell lines. Results: Despite a higher expression of BCR, cross-linking of BCR on WEHI-231 cell evoked a weaker level of tyrosine phosphorylation and BCR endocytosis than Bal 17 cells. Furthermore, the endocytosed BCR could not enter the lysosomal compartment and stayed as peripheral spots in WEHI-231 cells. Conclusion: WEHI-231 cell showed preferred BCR-mediated signaling pathways leading to a reduced capability of antigen presentation as well as the enhanced apoptosis in comparision with Bal 17 cells. These results might reflect the signaling differences between mature and immature B cells.

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Inhibition of Transglutaminase and Microbial Transglutaminase Activity by Garlic

  • Lee, Nam-Hyouck;Takeuchi, Atsuyoshi;Konno, Kunihiko
    • Food Science and Biotechnology
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    • 제16권2호
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    • pp.223-227
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    • 2007
  • Ground garlic inhibited the cross-linking reaction of myosin and incorporation of monodansylcadaverine (MDC) in salted Alaska pollack surimi catalyzed by transglutaminase (TGase). The component responsible for the inhibition was a thermostable, low molecular weight compound. The component also inhibited microbial transglutaminase (MTGase). The inhibition by garlic was reversibly recovered upon addition of 2-mercaptoethanol. The inhibitory component was therefore hypothesized to contain sulfhydryl groups within its structure. Alliin itself did not inhibit the cross-linking reaction. However, the addition of alliin together with garlic increased the inhibition. This result suggested that compounds derived from alliin was responsible for the inhibition of TGase activity.

Preparation and Characteristics of High Voltage Liquid Silicone Rubber by Modified Cross-linking Agent

  • Jung, Se-Young;Kim, Byung-Kyu
    • Transactions on Electrical and Electronic Materials
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    • 제10권1호
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    • pp.9-15
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    • 2009
  • There is a growing demand for a high voltage silicone rubber composite with high mechanical property and high electrical property. The effect of modified cross-linking agent on the mechanical, electrical properties, and short-circuit test performance of silicone rubber insulators have been investigated. To use base polymer, the various silicone polymers were prepared by the equilibrium polymerization. Aluminum trihydrate surface was treated by vinyl silane. Liquid silicone rubber nanocomposite was prepared from the compounding of VPMPS, HPDMS, catalyst, and alumina trihydrate modified with 1,3,5-trivinyl-l,3,5-trimethylcyclotrisiloxane. The mechanical property and electrical property for insulation materials were measured, indicating the high tensile strength and the good short-circuit property.

가교제와 가교조제 함량에 따른 XLPE의 절연특성 (Insulation properties of XLPE by adding Cross-linking Agent and Cross-linking Agent and Cross-linking Co-agent)

  • 김규식;임기조;손원근;박수길
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 하계학술대회 논문집
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    • pp.715-718
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    • 2000
  • We studied about electrical, chemical and mechanical characteristics of XLPE by dicumyl peroxide(DCP) and trimethylolpropane triacrylate(TMPTA) content ratio. DCP content was changed from 1.0 to 2.Sphr increasing 0.5phr. TMPTA content was changed 0.5 to 1.5phr increasing 0.5phr. Thermal analysis (DSC) was carried out in order to observe tendency of Tg according to DCP and TMPTA content. Tensile strength was measured in order to observe mechanical strength. In experimental results, content DCP 2.0phr and TMPTA 1.0phr has highest breakdown strength. Content DCP 2.0phr and TMPTA 0.5phr has lowest dielectric constant. Tendency of Tg did not affected by DCP and TMPTA content. Breakdown strength and Specific inductive capacity was measured.

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The Effect of Chemical Structure of Main Monomers and Cross-linking Monomers for Acrylic Co-polymers

  • Kang, Eun-Jin;Cheon, Ji-Yeon;Lee, Yoon-Gu;Choi, Jae-Hong
    • Elastomers and Composites
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    • 제57권2호
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    • pp.29-39
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    • 2022
  • In this research, the relationships between the chemical structures of 10 different acrylate monomers with 3 different cross-linking monomers were evaluated. The thermal stabilities of the prepared copolymers were evaluated by their weight-loss percentage through thermogravimetric analysis, and their glass-transition temperatures were analyzed using differential scanning calorimetry. Based on the results, some relationships between the chemical structures of the monomers and their properties were derived and are discussed herein.

DOI 서비스의 중심 CrossRef와 KISTI의 DOI Center (CrossRef the leading DOI service organization & DOI Center in KISTI)

  • 오혜민;조은진;강무영
    • 한국정보관리학회:학술대회논문집
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    • 한국정보관리학회 2011년도 제18회 학술대회 논문집
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    • pp.67-70
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    • 2011
  • 국내학술지의 국제적 이용과 인용확대를 위해 국가출연기관인 한국과학기술정보연구원(KISTI)은 CrossRef에 Co-Sponsoring Member로 가입하여 디지털 콘텐츠의 식별과 접근을 위한 고유 식별 체계인 DOI(Digital Object Identifier) 번호부여 및 DOI 기탁사업을 추진해오고 있다. CrossRef는 논문, 회의자료, 단행본 자료의 DOI 기탁업무를 수행하는 전 세계적인 비영리기관이며 DOI에 기반하여 Cited-by linking 서비스를 시행하고 이용자들의 필요에 따른 다양한 학술서비스를 제공하고 있다. 따라서 본 논문에서는 CrossRef에서 시행하는 서비스인 DOI, CrossCheck, Cited-by linking을 소개하고 KISTI를 통한 CrossRef서비스와 KISTI에서 운영하는 DOI Center 대해 기술하고자 한다.

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