• Title/Summary/Keyword: cross-linking

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

  • Ryu, Chong-Min;Nam, Young-Hee;Lee, Seung-Hyun;Kim, Hyung-Il;Lim, Dong-Hyuk;Kim, Hyun-Joong;Kim, Kyung Man
    • Journal of Adhesion and Interface
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    • v.10 no.3
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    • pp.134-140
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    • 2009
  • The acrylic copolymers with variation in side chain were synthesized based on molecular design. Wettability and adhesion properties on the wafer surface were investigated for these acrylic copolymer pressure sensitive adhesives. Three-dimensional networks of linear acrylic copolymers were produced with epoxy-type Tetra-DX cross-linking agent. The effect of cross-linking on adhesion characteristics was investigated. The side chain of acrylic copolymer played more important role in wettability than the interfacial interaction. As the degree of cross-linking increased, both probe tack and peel strength decreased. Also, heat resistance measured by SAFT increased with cross-linking; however, it showed the deterioration when excess cross-linking agent was added.

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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 (벌개미취 에탄올추출물의 STZ-유도 당뇨 모델에서의 최종당화산물의 생성 및 교차결합에 미치는 효과)

  • Kim, Junghyun;Kim, Chan-Sik;Kim, Jin Sook
    • Korean Journal of Pharmacognosy
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    • v.47 no.4
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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.

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

  • Bae, Chun-Ho;Park, Heui-Dong
    • Food Science and Preservation
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    • v.19 no.2
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    • pp.216-222
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    • 2012
  • The optimum annealing conditions of corn starch slurry were studied for RS4 type resistant starch production by phosphorylated cross-linking. When a corn starch slurry was cross-linked by using phosphate salts (STMP/STPP mixture) in the presence of 0.9%, 1.2% and 1.5% NaOH/st.ds, a high concentration of NaOH resulted in a rapid increase of the RS contents at the early reaction stage. However, similar RS contents were obtained after 12 h of cross-linking regardless of NaOH concentrations. The annealing treatment was conducted under various conditions such as pH between 2-10, temperature $40-60^{\circ}C$, time 0-14 h followed by phosphorylated cross-linking. The lower slurry pH was for the annealing treatment, the higher RS contents were obtained after cross-linking. When the slurry annealed for various period of time and temperature, a maximal amount of RS was formed after 2 h of annealing at $50^{\circ}C$ of annealing temperature of the starch slurry (pH 2.0). Therefore, an optimal annealing conditions at pH 2.0 and $50^{\circ}C$ for 2 h were proposed under the cross-linking conditions of sodium sulfate 10%/st.ds, NaOH 1.2%/st.ds and 12 h of the reaction time. The RS contents were linearly increased with the increase of phosphate salt addition. The RS4 prepared under the optimal conditions contained RS 72.3% and its phosphorus content was 0.36%/st.ds, which was below the limit (0.4%/st.ds) of modified starch by Korea Food Additives Code.

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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    • v.9 no.2
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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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    • v.1 no.3
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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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    • v.16 no.2
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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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    • v.10 no.1
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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.

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

  • 김규식;임기조;손원근;박수길
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.07a
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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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    • v.57 no.2
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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.

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

  • Oh, Hye-Min;Cho, Eun-Jin;Kang, Mu-Yeong
    • Proceedings of the Korean Society for Information Management Conference
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    • 2011.08a
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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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