• 제목/요약/키워드: cross linking

검색결과 662건 처리시간 0.026초

Is dentin biomodification with collagen cross-linking agents effective for improving dentin adhesion? A systematic review and meta-analysis

  • Julianne Coelho Silva;Edson Luiz Cetira Filho;Paulo Goberlanio de Barros Silva;Fabio Wildson Gurgel Costa;Vicente de Paulo Aragao Saboia
    • Restorative Dentistry and Endodontics
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    • 제47권2호
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    • pp.23.1-23.18
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    • 2022
  • Objectives: The aim of this investigation was to evaluate the effectiveness of collagen cross-linking agents (CCLAs) used in combination with the adhesive technique in restorative procedures. Materials and Methods: In this systematic review, the authors followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist. An electronic search was performed using PubMed, Scopus, Web of Science, Cochrane Library, LILACS, and DOSS, up to October 2020. The gray literature was also researched. Only randomized clinical trials were selected. Results: The selection process yielded 3 studies from the 838 retrieved. The addition of CCLAs in the retention of restorations increased the number of events. The postoperative sensitivity scores and marginal adaptation scores showed no significant difference between the CCLA and control groups, and the marginal pigmentation scores showed a significant increase in the CCLA group. There were no caries events in any group throughout the evaluation period. Conclusions: This systematic review showed that there is no clinical efficacy to justify the use of CCLAs in the protocols performed.

Effect of Cross-Linking Characteristic on the Physical Properties and Storage Stability of Acrylic Rubber

  • Seong-Guk Bae;Min-Jun Gim;Woong Kim;Min-Keun Oh;Ju-Ho Yun;Jung-Soo Kim
    • Elastomers and Composites
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    • 제58권3호
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    • pp.136-141
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    • 2023
  • Polyacrylic rubber (ACM) is well known for its excellent heat resistance and chemical stability. Additionally, its performance can be readily manipulated by modifying its functional groups, rendering it highly attractive to various industries. However, extreme climate changes have necessitated an expansion of the operating temperature range and lifespan of ACM products. This requires the optimization of both the compounding process and functional-group design. Hence, we investigated the relationship between the cross-linking system and mechanical properties of an ACM with a carboxylic cure site. The crosslink density is determined by chemical kinetics according to the structure of additives, such as diamine crosslinkers and guanidine accelerators. This interaction enables the manipulation of the scotch time and mechanical properties of the compound. This fundamental study on the correlation analysis between cross-linking systems, physical properties, and storage stability can provide a foundation for material research aimed at satisfying the increasingly demanding service conditions of rubber products.

Effect of a Bacterial Laccase on the Quality and Micro-Structure of Whole Wheat Bread

  • Jingjing Wang;Han Bai;Ran Zhang;Guoao Ding;Xuran Cai;Wei Wang;Guilan Zhu;Peng Zhou;Yan Zhang
    • Journal of Microbiology and Biotechnology
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    • 제33권12호
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    • pp.1671-1680
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    • 2023
  • The gluten protein content in whole-wheat flour is low, which affects the elasticity and viscosity of the dough. Enzymatic modification of the protein may result in a network that mimics gluten, which plays an important role in the processing of whole-wheat foods. In this study, the effects of Halomonas alkaliantartica laccase (LacHa) on the quality parameters of whole-wheat bread were investigated. The optimum dosage of LacHa was 4 U/100 g of whole-wheat flour. At this dosage, whole-wheat bread exhibited the best specific volume and optimum texture parameters. Laccase also extended the storage duration of whole-wheat bread. We analyzed the micro-structure of the dough to determine its gluten-free protein extractable rate and free sulfhydryl group content, and verify that LacHa mediates cross-linking of gluten-free proteins. The results demonstrated that the cross-linking of gluten-free protein by LacHa improves the texture of whole-wheat bread. As a flour improver, LacHa has great developmental and application potential in baked-food production.

국내학술정보 DOI 기반서비스 효과분석 및 응용에 관한 연구 (Application and Effect Analysis of DOI based Service for National Academic Information)

  • 정은경;김병규;박재원
    • 한국정보관리학회:학술대회논문집
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    • 한국정보관리학회 2010년도 제17회 학술대회 논문집
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    • pp.29-32
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    • 2010
  • 국내학술지의 국제적 이용과 인용확대를 위해 국가출연기관인 KISTI에서 학술논문 디지털 식별자인 DOI 번호부여 및 DOI 기탁사업을 추진해오고 있다. 그리고 DOI를 기반으로 학술지간 인용을 확인할 수 있는 Cited-by linking 서비스를 제공하고 있다. 이 논문에서는 KISTI를 통해 기탁된 과학기술분야 논문들을 대상으로 CrossRef의 DOI기반 서비스인 Cited-by linking을 이용하여 학술지간 인용결과를 알아보고 인용확대를 위한 방법을 제시하고자 한다.

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Effective α-Helix Stabilization via Hexenyl Propionate Cross-Link

  • Yoo, Jiyeon;Kim, Young-Woo
    • Bulletin of the Korean Chemical Society
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    • 제35권12호
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    • pp.3627-3631
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    • 2014
  • In this study we examined two ester-containing cross-links, hex-2-enyl acetate and hex-2-enyl propionate, as new cross-linking systems for helix stabilization of short peptides. We demonstrated that these hexenyl ester cross-links can be readily installed via a ruthenium-mediated ring-closing metathesis reaction of L-aspartic acid 4-allyl ester or L-glutamic acid 5-allyl ester at position i and (S)-2-(4'-pentenyl)alanine at position i+4 using second generation Hoveyda-Grubbs catalyst at $60^{\circ}C$. Between these two cross-links, we found that the hex-2-enyl propionate significantly stabilizes the ${\alpha}$-helical conformations of short model peptides. The helix-stabilizing effects of the hex-2-enyl propionate tether appear to be as powerful as Verdine's i,i+4 all-hydrocarbon stapling system, which is one of the most widely used and the most potent helix-stabilizing cross-linking systems. Furthermore, the hex-2-enyl propionate bridge is reasonably robust against non-enzymatic hydrolytic cleavage at a physiological pH. While extended studies for probing its chemical scopes and biological applications are needed, we believe that this new helix-stabilizing system could serve as a useful chemical tool for understanding protein folding and designing conformationally-constrained peptide drugs.

동결건조 어육의 단백질 Cross-linking에 관한 연구 (Protein Cross-linking in Freeze Dried Fish Meat)

  • 이강호;정우진;서재수;정인학;김충곤
    • 한국수산과학회지
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    • 제19권2호
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    • pp.100-108
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    • 1986
  • This study was carried out in order to investigate protein cross-linking in freeze-dried meat of flounder (Limanda herzensteini). Changes in solubility or extractability of proteins and electrophoretic patterns of the extracted proteins were determined to monitor the cross-linking during the storage of freeze-dried meat. Development of nonenzymatic browning and the loss of in vitro protein digestibilily were also measured to assess their influences on the changes of functional and nutritional properties of proteins. In addition, the effects of lysine added, and removal of fat and water extractives were also mentioned. The extractability of protein decreased upon storage time and temperature, and the loss of solubility of myosin was evident. In case of the samples stored at $5^{\circ}C$ for 150 days, the extractability of protein decreased $26.4\%$, while that of the samples stored at $20^{\circ}C$ for 60 days decreased about $39.7\%$. And it was noted that the loss of solubility of myosin was $68.3\%$ and $98.1%$ for the same storage conditions, respectively. It was noteworthy that the samples treated with $L-lysine{\cdot}HCl$ seemed to prevent more or less the loss of protein solubility, in that, even stored at $20^{\circ}C$ for 120 days, revealed only $57.03\%$ decrease. The nonenzymatic browning was proceeded with the increase of storage temperature, especially, in the samples treated with glucose. This suggests that the decrease in extractibility of myosin was accompanied by the extent of browning. But the browning was retarded in defatted samples. The in vitro apparent protein digestibility was also higher in the samples defatted or water extracted. It was suggested from these results that changes in properties of proteins in freeze dried fish meat were led by the protein cross-linking which was attributed to Maillard type of reactions and protein-lipid interactions.

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The Anti-calcification Effect of Dithiobispropionimidate, Carbodiimide and Ultraviolet Irradiation Cross-linking Compared to Glutaraldehyde in Rabbit Implantation Models

  • Park, Samina;Kim, Soo Hwan;Lim, Hong-Gook;Lim, Cheong;Kim, Yong Jin
    • Journal of Chest Surgery
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    • 제46권1호
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    • pp.1-13
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    • 2013
  • Background: Glutaraldehyde (GA) is a widely used cross-linking agent for improving mechanical properties and resistance to enzymatic degradation of collagenous tissue, but it has several drawbacks such as calcification and cytotoxicity. The aim of this study was to find the alternative effective cross-linking methods to GA. Materials and Methods: Bovine pericardium was processed with GA with ethanol+octanol and glycine detoxification, and polyethylene glycol (PG) space filler, dimethyl 3,3'-dithiobispropionimidate (DTBP), 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) treatment, and the physical fixation of ultraviolet irradiation were done. The biologic material properties of variously treated pericardial tissues were assessed by biochemical, mechanical and histological tests. Treated pericardial tissues were also implanted subcutaneously or intramuscularly into the rabbit for 10 weeks to assess the xenoreactive antibody response of immunoglobulin G and M, their anti-calcification effect. Results: The biochemical and mechanical properties of EDC fixed pericardial tissues were comparable to the GA fixed tissue. The cytotoxicity was lowest in space filler treated GA fixed group. In rabbit subcutaneous or intramuscular implantation models, decellularization, space filler, EDC treatment group showed significantly lower calcium content than GA only and DTBP treatment group (p<0.05, analysis of variance). The titer of anti $Gal{\alpha}1-3Gal{\beta}1$-4GlcNAc-R antibodies did not change in the postimplantation serial enzyme-linked immunosorbent assay. Hematoxylin and eosin and von Kossa staining showed that decellularization, space filler, EDC, and ultraviolet treatment had less inflammatory cell infiltration and calcium deposits. Conclusion: The decellularization process, PG filler, and EDC treatments are good alternative cross-linking methods compared to GA only fixation and primary amine of DTBP treatment for cardiovascular xenograft preservation in terms of the collagen cross-linking stability and in vivo anti-calcification effects.

UV 중합을 활용하여 제조된 열경화형 아크릴 점착제의 경화특성 및 접착특성 분석 (Curing Behaviours and Adhesion Performance of Thermal Cured Acrylic PSAs Synthesized by UV-polymerization)

  • ;이승우;백종호;박지원;김현중
    • 접착 및 계면
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    • 제19권2호
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    • pp.74-82
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    • 2018
  • 아크릴레이트 기반의 점착제를 가교 시키는 기술은 다양하게 소개되어 왔다. 본 연구에서는 에폭시 변성 단량체와 메틸아지리딘 가교제를 활용하여 높은 가교 밀도를 가지는 아크릴 구조체를 만들었다. 베이스구조체를 제조하기 위해서 빠른 제조 공정이 가능하고 무용제 공정이 가능한 UV 중합 기술을 활용했다. FT-IR, 경화거동 및 접착특성 평가를 통해 UV경화도 및 2차경화 온도에 따른 특성 변화를 확인하고자 하였다. 겔분율은 선경화 $800mJ/cm^2$, 120도 후 경화온도 조건에서 50%이상 확보할 수 있었으며, 180도 경화조건에서 80%이상 확보 할 수 있었다. 경화 시간이 길어짐에 따라 경화도가 100%에 도달하였으며 이를 통해 열경화를 통한 2차 경화가 효과적임을 확인 할 수 있었다.

Preparation and Mechanical Properties of Wheat Protein Isolate Films Cross-linked with Resorcinol

  • Chandrasekhar, M.;Prabhakar, M.N.;Song, Jung-Il
    • Composites Research
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    • 제28권2호
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    • pp.40-45
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    • 2015
  • The purpose of the present work was to preparation and study of full biodegradable Eco-friendly bio-composites by using renewable resources. In this study, wheat protein isolate (WPI) films were formed by cross linking with resorcinol through solution casting method for packaging applications. By varying the resorcinol content (10, 20, 30, 40, and 50 wt %), its effect on mechanical properties of the wheat protein isolate film was measured. The addition of 20% resorcinol led to an overall increase in the tensile strength from 5.2 to 18.6 MPa and modulus increase from 780 to 1132 MPa than WPI films. The % elongation was increased from 2.8 to 9.05 when compared to unmodified WPI film. A thermal phase transition of the prepared WPI was assessed by means of DSC. FTIR is evident that the characteristic WPI spectral IR bands shifted on cross-linking with resorcinol.

Base Specificity for DNA Interstrand Cross-Linking Induced by Anticancer Agent Bizelesin

  • Lee, Chong-Soon;Myung, Pyung-Keun;Gibson, Neil W.
    • Archives of Pharmacal Research
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    • 제19권3호
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    • pp.191-196
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    • 1996
  • Bizelesin is a promising novel anticancer agent which is known to alkylate N3 of adenine to induce DNA interstrand cross-links (ISC) with in $5^I-TAATTA\; and\; 5^I-TAAAAAA$. We have investigated the base specificity for DNA ISC induced by bizelesin using oligomers containing the cross-linkable sequence $5^I-TAATTA\; and\; 5^I-TAAAAAA$. in which "N" was either A, C, G, or T. An analysis of denaturing polyacrylamide gel showed that bizelesin is able to induce DNA ISC in the duplex oligomer containing sequences $5^I-TAATTA\; and\; 5^I-TAAAAAA$. The formation of interstrand crosslinking did not occur in the sequences $5^I-TAATTA\; and\; 5^I-TAAAAAA$. DNA strand cleavage assay to determine the cross-linking site within $5^I-TAATTA$sequence showed that bizelesin alkylates guanine. These results demonstrate that bizelesin is able to induce DNA ISC at guanine but not at cytosine or thymine. In addition, guanine adducts have been found to be susceptible to DNA strand cleavage by exposure to hot piperidine. The extent of DNA strand cleavage, however, was not 100% efficient in either neutral pH buffer or hot piperidine.

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