• 제목/요약/키워드: cross-linking

검색결과 659건 처리시간 0.039초

Hydrophobic modification of PVDF hollow fiber membranes using polydimethylsiloxane for VMD process

  • Cui, Zhaoliang;Tong, Daqing;Li, Xue;Wang, Xiaozu;Wang, Zhaohui
    • Membrane and Water Treatment
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    • 제10권4호
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    • pp.251-257
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    • 2019
  • Fabricating hydrophobic porous membrane is important for exploring the applications of membrane distillation (MD). In the present paper, poly(vinylidene fluoride) (PVDF) hollow fiber membrane was modified by coating polydimethylsiloxane (PDMS) on its surface. The effects of PDMS concentration, cross-linking temperature and cross-linking time on the performance of the composite membranes in a vacuum membrane distillation (VMD) process were investigated. It was found that the hydrophobicity and the VMD performance of the PVDF hollow fiber membrane were obviously improved by coating PDMS. The optimal PDMS concentration, cross-linking temperature and cross-linking time were 0.5 wt%, $80^{\circ}C$, and 9 hr, respectively.

UCI 상호참조에 기반한 참조연계시스템의 구현 (Establishment of Reference Linking Systems on UCI Cross-Reference)

  • 박승범;이상원
    • 한국IT서비스학회지
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    • 제12권1호
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    • pp.115-130
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    • 2013
  • This paper describes Cross reference services in Knowledge contents based on UCI. Cross references are effective features that can increase the value of the contents. Knowledge contents include academic papers, research reports, archives, historical and cultural heritage, and professional databases. Cross references are consists of reference-to and cited-by links which can be made by reference list in article. Some of cross reference services provided are considered. We designed cross reference services for knowledge contents in Korea and prototype services are provided. The reference linking service in the area of national R&D will enable the linking of heterogeneous information produced at different sources.

Investigation of Transglutaminase-Induced Peptide Cross-Linking by Matrix-Assisted Laser Desorption / Ionization Time-of-Flight Mass Spectrometry

  • 김희준;임효섭
    • Bulletin of the Korean Chemical Society
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    • 제20권11호
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    • pp.1299-1302
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    • 1999
  • Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) was used to demonstrate cross-linking of peptides induced by transglutaminase. The presence of ε-( Υ-glutamyl)lysine isopeptide cross-link in the acid hydrolysate of the cross-linking reaction mixture was also demonstrated by MALDI-TOF-MS without prior separation. MALDI-TOF-MS quickly provided peptide mass maps after pronase digestion of the cross-linked peptide adduct, which enabled us to monitor the hydrolytic sequence. Pronase appears to preferentially hydrolyze peptide bonds distant from the cross-link before hydrolyzing peptide bonds around the cross-link. The results suggest that pronase digestion followed by MALDI-TOF-MS could be used for determination of amino acid sequence around a modification site.

페닐기 함유 열경화성 폴리유기실록산 코팅제 특성 (Characteristics of Heat Curable Polyorganosiloxane Coating Materials)

  • 이진혁;강두환;강호종
    • 폴리머
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    • 제39권3호
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    • pp.499-505
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    • 2015
  • Dimethyldimethoxysilane(DMDMS), methyltrimethoxysilane(MTMS)과 phenyltrimethoxysilane(PTMS)을 이용하여 폴리유기실록산 열 경화성 코팅액을 제조하고 가교도와 페닐기 함량이 코팅액과 도막 물성에 미치는 영향을 살펴보았다. Si-NMR 측정에서 얻어진 D $T^{Me}$ $T^{Ph}$ 구조 코팅액 조성비가 사용된 DMDMS, MTMS, PTMS의 몰 비로부터 얻어진 이론치와 일치함을 확인할 수 있었다. 가교밀도가 높을수록 그리고 페닐 함량이 낮을수록 실록산 결합의 증가에 의하여 코팅액 분자량이 증가됨을 알 수 있으며 페닐기 증가는 코팅액 굴절률 증가에 매우 큰 영향을 미침을 알 수 있었다. 가교밀도가 높을수록, 페닐기 함량이 감소할수록 코팅도막 경도는 증가되었으며 내열특성 또한 우수해짐을 확인할 수 있었다. 이상의 결과로부터 같은 실록산 결합을 갖는 폴리유기실록산 코팅제라도 치환도에 따른 가교도 조절과 페닐기 함량에 따라 코팅액 물성이 달라짐을 확인할 수 있었다.

산수유 씨의 최종당화산물의 형성 및 교차결합에 미치는 효과 (Inhibitory Effects of the Seeds of Cornus officinalis on AGEs Formation and AGEs-induced Protein Cross-linking)

  • 김찬식;장대식;김정현;이가영;이윤미;김영숙;김진숙
    • 생약학회지
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    • 제39권3호
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    • pp.249-254
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    • 2008
  • An 80% EtOH extract and the solvent fractions of the seeds of Cornus officinalis were evaluated for their inhibitory activities against advanced glycation end products (AGEs) formation and AGEs-induced protein cross-linking in vitro. In vitro assay for AGEs-bovine serum albumin (BSA) formation showed that the 80% EtOH extract, n-hexane, EtOAc, n-BuOH and water fractions significantly inhibited AGEs formation with observed $IC_{50}$ values of 1.13, 17.64, 1.52, 1.24 and $3.27{\mu}g/ml$, respectively. In indirect AGEs-ELISA assay, the 800% EtOH extract, EtOAc and n-BuOH fractions exhibited more potent inhibitory activity on AGEs-BSA formation than aminoguanidine, a well know AGEs inhibitor. Furthermore, the 80% EtOH extract and all the solvent fractions inhibited concentration-dependently AGE-BSA cross-linking to collagen. The 80% EtOH extract, EtOAc, n-BuOH and water fractions also had a breaking activity against preformed AGE-BSA cross-linking concentration dependently. Thus these results suggest that the 80% EtOH extract and fractions of the seeds of C. officinalis could be an inhibitor as well as breaker of AGE-BSA cross-linking.

가교도가 조절된 세공충진 이온교환막의 제조 및 전기화학적 응용: Part II. 역 전기투석 (Preparation and Electrochemical Applications of Pore-filled Ion-exchange Membranes with Well-adjusted Cross-linking Degrees: Part II. Reverse Electrodialysis)

  • 송현비;문하늘;김도형;강문성
    • 멤브레인
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    • 제27권5호
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    • pp.441-448
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    • 2017
  • 본 연구에서는 다공성 폴리에틸렌 지지체를 기반으로 세 가지 가교제를 혼합 도입한 세공충진 이온교환막을 제조하고 역 전기투석에서 멤브레인의 특성이 발전성능에 미치는 영향을 고찰하였다. 실험 결과, 분자 크기가 다른 가교제를 혼합함으로써 이온교환막의 가교도 및 자유체적이 효과적으로 조절됨을 확인하였으며 상관 분석을 통해 멤브레인의 전기화학적 특성 및 이를 적용한 역 전기투석의 발전성능에 복합적인 영향을 미침을 알 수 있었다. 특히 세공충진 양이온 교환막은 최적 가교조건에서 상용막 대비 동등 이상의 발전 성능을 나타내었으며 음이온 교환막 또한 상용막에 근접하는 우수한 성능을 나타내었다.

참고문헌 자동파싱 및 참조링킹을 위한 Citation Matcher 연구 및 개발 (Research and Development of Citation Matcher for Reference Parsing and Cross-Reference Linking)

  • 이상기;김선태;이용식;이태석
    • 한국콘텐츠학회:학술대회논문집
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    • 한국콘텐츠학회 2007년도 추계 종합학술대회 논문집
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    • pp.426-429
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    • 2007
  • CrossRef에서는 DOI 식별자를 기반으로 출판사 간 참고문헌을 링크하기 위한 참조링킹 인프라를 제공하고 있으며, CrossRef과 연계한 참고문헌의 전자원문 링크 서비스인 참조링킹 체제를 구축하는 기관이 점차 늘고 있다. 본 연구에서는 참조링킹 체제를 효율적으로 구축하기 위해 Citation Matcher를 개발하였다. Citation Matcher는 과거 수작업에 의존하던 참고문헌 DB구축 및 식별자 매칭 프로세스를 자동화하고 패턴화한 것으로, 참고문헌을 원형 그대로 Copy & Paste하면, 참고문헌의 패턴을 분석하여 참고문헌으로부터 저널명, 저자, 권/호 등 Citation 정보를 일목요연하게 파싱하고, 파싱한 정보를 표준화된 방식으로 CrossRef, Pubmed, yesKISTI 등의 메타데이터와 매칭하여 식별자를 획득하여 링크하는 솔루션이다. Citation Matcher는 과거 사람이 수행하던 국내 학술논문의 참고문헌 구축 및 매칭 프로세스를 완전 자동화함으로써 업무 프로세스를 혁신하고, 정보자원 간 연계성 제고 및 논문 간 Seamless한 접근을 통해 이용 편리성을 제고하기 위한 것이다.

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Patterns of Citing Korean DOI Journals According to CrossRef's Cited-by Linking and a Local Journal Citation Database

  • Seo, Tae-Sul;Jung, Eun-Gyeong;Kim, Hwanmin
    • Journal of Information Science Theory and Practice
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    • 제1권2호
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    • pp.58-68
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    • 2013
  • Citing literature is a very important activity for scholars in writing articles. Many publishers and libraries build citation databases and provide citation reports on scholarly journals. Cited-by linking is a service representing what an article cites and how many times it cites a specific article within a journal database. Recently, information services based on DOIs (Digital Object Identifiers) have been increasing in number. CrossRef, a non-profit organization for the DOI registration agency, maintains the DOI system and provides the cited-by linking service. Recently, the number of Korean journals adopting DOI is also rapidly increasing. The Korea Institute of Science and Technology Information (KISTI) supports Korean learned societies in DOI related activities in collaboration with CrossRef. This study analyzes cited patterns of Korean DOI journal articles using CrossRef's cited-by linking data and a Korean journal citation database. This analysis has been performed in terms of publication country and the language of journals citing Korean journal articles. The results show that DOI, SCI(E) (Science Citation Index (Expanded)), and English journals are more likely to be cited internationally.

Dexamethasone Release from Glutaraldehyde Cross-Linked Chitosan Microspheres: In Vitro/In Vivo Studies and Non-Clinical Parameters Response in Rat Arthritic Model

  • Dhanaraju, Magharla Dasaratha;Elizabeth, Sheela;Poovi, Ganesan
    • Journal of Pharmaceutical Investigation
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    • 제41권5호
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    • pp.279-288
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    • 2011
  • The Dexamethasone (DEX) loaded chitosan microspheres were prepared by thermal denaturation and chemical cross-linking method using a dierent concentration of glutaraldehyde as chemical cross-linking agent. The prepared microspheres were evaluated for the percentage of Drug Loading (DL), Encapsulation Efficiency (EE) and surface morphology by Scanning Electron Microscopy (SEM). DL and EE were found to be maximum range of 10.0 to 10.79 % and 58.19 to 64.73 % respectively. The SEM Photographs of the resultant microspheres exhibited fairly smooth surfaces and predominantly spherical in appearance. In addition, Fourier Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC) shown that there was no interaction between the drug and polymer. In vitro and in vivo release studies revealed that the release of dexamethasone was sustained and extended up to 63 days and effectively controlled by the extent of cross-linking agent. Non-clinical parameters such as paw volume, hematological parameters like Erythrocyte Sedimentation Rate (ESR), Paced Cell Volume (PCV), Total Leucocytes Count (TLC), Hemoglobin (Hb), Differential Cell Count (DCC) were investigated in Fruend's Complete Adjuvant (FCA) induced arthritic rats. Radiology and histopathological studies were also performed in order to evaluate the therapeutic efficacy of the DEX-loaded microspheres in extenuating the rat arthritic model.

여러 가지 가교제가 인체 무세포진피의 안정성에 미치는 영향 (Effects of Cross-Linking Agents on the Stability of Human Acellular Dermal Matrix)

  • 강낙헌;윤영묵;우종설;안재형;김진영
    • Archives of Plastic Surgery
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    • 제35권3호
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    • pp.248-254
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    • 2008
  • Purpose: Human acellular dermal matrix(ADM) is widely used in the treatment of congenital anomalies and soft tissue deficiencies. But it is rapidly degraded in the body and does not provide satisfactory results. There is a need to improve collagen fiber stability through various methods and ultimately regulate the speed of degradation. Methods: The ADMs were added with various cross-linking agents called glutaraldehyde, dimethyl 3,3'-dithiobispropionimidate to produce cross-linked acellular dermal matrices. 1,4-butanediol diglycidyl ether solution was applied with a pH of 4.5 and 9.0, respectively. The stability of cross-linked dermal matrix was observed by measuring the shrinkage temperature and the degradation rates. The cross- and non-cross linked dermis were placed in the rat abdomen and obtained after 8, 12 and 16 weeks. Results: The shrinkage temperature significantly increased and the degradation rate significantly decreased, compared to the control(p<0.05). All of cross-linked dermises were observed grossly in 16 weeks, but most of non-cross linked dermis were absorbed in 8 weeks. Histologically, the control group ADM was found to have been infiltrated with fibroblasts and most of dermal stroma were transformed into the host collagen fibers. However, infiltration of fibroblasts in the experiment was insignificant and the original collagen structure was intact. Conclusion: Collagen cross-linking increases the structural stability and decreases degradation of acellular dermis. Therefore, decrease in body absorption and increase in duration can be expected.