• Title/Summary/Keyword: Adhesions

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Structures and Physical Properties of in situ composite based on Liquid Crystalline Polymer and Poly(ethylene 2,6-naphthalate) Blends

  • Yoo, Hyun-Oh;Kim, Seong-Hun;Hong, Soon-Man;Hwang, Seung-Sang
    • Proceedings of the Korean Fiber Society Conference
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    • 1998.10a
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    • pp.236-239
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    • 1998
  • The in situ composites based on poly(ethylene 2,6-naphthalate) and thermotropic liquid crystalline polymer (LCP) have been an area of increasing interest and study, since LCP exhibits high chemical stabilities and excellent thermo mechanical properties such as high strength and modulus. In a binary, however, poor compatibility and interfacial adhesions between two phases frequently results in deteriorated mechanical properties. (omitted)

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Cellular Adhesions and Protein Dynamics on Carbon Nanotube/Polymer composites Surfaces

  • Gang, Min-Ji;Wang, Mun-Pyeong;Im, Yeon-Min;Kim, Jin-Guk;Gang, Dong-U
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2010.05a
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    • pp.45.2-45.2
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    • 2010
  • Possessing of carbon nanotubes in biopolymer intrigued much interest due to their mechanical and unique nanoscale surface properties. Surface stiffness can be controlled by the amount of carbon nanotubes in polymer and surface wettability can be altered by the order of nanoscale surface roughness. Protein adsorption mechanism on nanostructured carbon nanotube/polymer thin film will be discussed in this study. In addition, we identified that mechanical stimuli also contribute the messenchymal stem cell and bone cell interactions. Importantly, live cell analysis system also showed altered morphology and cellular functions. Thus, embedding of carbon nanostructures simultaneously contribute to protein adsorption and cellular interactions. In conclusion, this study demonstrated the evidence that nanoscale surface features determine the subsequent biological interactions, such as protein adsorption and cellular interactions.

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Surgery of the Infected Patent Ductus Arteriosus with Teflon Wrapping (세균성 동맥내막염을 동반한 개방성 동맥관의 치험예)

  • 조범구
    • Journal of Chest Surgery
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    • v.5 no.1
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    • pp.25-28
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    • 1972
  • Patent ductus arteriosus is one of the most common congenital heart diseases, which treated operatively has excellent results. Treatment by surgical means is common and invariably successful. However,infected PDA cases present problems and surgeons operating must face the possibility of adhesions,aneurysmal dilatation and friabiilty of tissue with tearing of the pulmonary arterial end, especially, which causes a fatal hemorrhagic ccmplication. In the earlier days of cardiac surgery, many surgeons deferred operative treatment infected PDA because of frequent complications, high postoperative morbidity and mortality. This continued until Touroff et al. successfully divided the infected PDA in 1940. In 1944, Harper et aI. have used Cellophane for the wrapping of the infected PDA. This surgical procedure has become a single, simple and safe method for treating infected PDA, since that time. In the Teflon wrapping technique, a cardiothoracic team of Yonsei University Severance Hospital used Teflon felt instead of Cellophane in one case of infected PDA and this method proved intractable to antibiotic treatment for 40 days.

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Posttraumatic Stiffness (외상 후 동결견)

  • Choi, Chang-Hyeok
    • Clinics in Shoulder and Elbow
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    • v.9 no.1
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    • pp.14-19
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    • 2006
  • The patient with a posttraumatic stiffness frequently has a history of prolonged immobilization after a traumatic event. Adhesions in the extraarticular humeroscapular motion interface may be present independently or in combination with intraarticular capsular contractures. A through history and physical examination usually reveal the cause and anatomic location of stiffness. Passive stretching exercise program is effective as a first line treatment, but manipulation under anesthesia is usually not effective because of potential complication such as fracture, tendon rupture and neurologic injury. The humeroscapular motion interface adhesion can be released either open or arthroscopically. The combined technique coupled with an aggressive rehabilitation program can provide more effective motion restoration and pain relief.

Influence of Oxyfluorination on Physicochemical Characteristics of Carbon Fibers and their Reinforced Epoxy Composites

  • Seo, Min-Kang;Park, Soo-Jin
    • Macromolecular Research
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    • v.17 no.6
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    • pp.430-435
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    • 2009
  • The effect of oxyfluorination temperature on the surface properties of carbon fibers and their reinforced epoxy composites was investigated. Infrared (IR) spectroscopy results for the oxyfluorinated carbon fibers revealed carboxyl/ester (C=O) and hydroxyl (O-H) groups at 1632 and 3450 $cm^{-1}$, respectively, and that the oxyfluorinated carbon fibers had a higher O-H peak intensity than that of the fluorinated ones. X-ray photoelectron spectroscopy (XPS) results indicated that after oxyfluorination, graphitic carbon was the major carbon functional component on the carbon fiber surfaces, while other functional groups present were C-O, C=O, HO-C=O, and $C-F_x$. These components improved the impact properties of oxyfluorinated carbon fibers-reinforced epoxy composites by improving the interfacial adhesion between the carbon fibers and the epoxy matrix resins.

Effect of Coating Weight of Electroplated Sheet Steels on Quality Performances for Automotive Body Panels (자동차용 전기도금강재의 도금재착항별 품질생성)

  • 김태영;진영술
    • Journal of the Korean institute of surface engineering
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    • v.25 no.2
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    • pp.57-65
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    • 1992
  • Increasing demands of high corrosion resistant sheet steels for the automotive body panels have been leading to a tendency toward heavier coatings of electroplated sheet steels. The specimens were prepared from lab-scale electroplating simulator with various coating weights of zinc, zinc-iron and zinc-nickel coated sheet steels and evaluated in the light of the application for the automotive body panels. Corrosion resistances by sacrificial action were improved with increasing coating weights for all electroplated sheet under survey, but blistering resistances of pure zinc coated sheet steels were not as much. On the other hand, the adhesions of heavy alloy coatings showed poor powdering performances by the external compressive or tensile forces.

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Five Cases of Pregnancies after Unsuccessful IVF-ET Attempts with Additional Non IVF-ET Therapy or without Therapy (체외수정.배이식 불성공후의 자연주기에 임신이 성립된 5예)

  • Bai, Byoung-Choo
    • Clinical and Experimental Reproductive Medicine
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    • v.27 no.1
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    • pp.111-116
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    • 2000
  • IVF-ET therapy was originally developed as a method for treating patients with absolute mechanical infertility for whom spontaneous conception is almost impossible. Objective: To report that the recent IVF-ET is now applied to couples not only untreatable tubal infertility but also peritubal periovarial adhesions, endometriosis, male-related or unexplained infertility. Material and Method: Case report. Result: We experienced 5 Pregnancies after unsuccessful IVF-ET attempt with additional non IVF-ET therapy or without therapy. Conclusions: The follicular puncture and ovarian enlargement may result in restoration of pituitary-ovarian axis and peritoneal environment in infertility patients.

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Characterization of Tribological Properties of DLC Films Prepared by Different Deposition Method (증착방법에 따른 DLC 막의 마찰-마모 특성평가)

  • Oh, Yoon-Suk
    • Journal of the Korean Ceramic Society
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    • v.46 no.5
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    • pp.497-504
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    • 2009
  • DLC is considered as the candidate material for application of moving parts in automotive components relatively in high pressure and temperature operating conditions for its high hardness with self lubrication and chemical inertness. Different deposition method such as arc plating, ion gun plating and PECVD were used for comparing mechanical and tribological properties of each DLCs deposited on stainless steel with 1 um thick respectively. Among these 3 types of DLCs, the arc plated DLC film showed highest value for wear resistance in dry condition. From the results of analysis for physical properties of DLC films, it seems that the adhesion force and crack initiation modes were more important factors than intrinsic mechanical properties such as hardness, elastic modulus and/or roughness to the wear resistance of DLC films. Raman spectroscopy was used for understanding chemical bonding natures of each type of DLC films. Typical D and G peaks were identified based on the deposition method. Hardness of the coating layers were identified by nanoindentation method and the adhesions were checked by scratch method.

Regulation of Hippo signaling by actin remodeling

  • Seo, Jimyung;Kim, Joon
    • BMB Reports
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    • v.51 no.3
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    • pp.151-156
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    • 2018
  • The Hippo signaling pathway controls nuclear accumulation and stability of the transcriptional coregulator YAP and its paralog TAZ. The activity of Hippo-YAP signaling is influenced not only by biochemical signals, but also by cell shape and mechanical tension transmitted through cell-cell junctions and cell-matrix adhesions. Data accumulated thus far indicates that the actin cytoskeleton is a key mediator of the regulation of Hippo-YAP signaling by means of a variety of biochemical and mechanical cues. In this review, we have outlined the role of actin dynamics and actin-associated proteins in the regulation of Hippo-YAP signaling. In addition, we discuss actin-mediated regulation of YAP/TAZ activity independent of the core Hippo kinases MST and LATS. Although our understanding of the link between Hippo-YAP signaling and the actin cytoskeleton is progressing rapidly, many open questions remain.

The Effects of Interlayer on the DLC Coating (중간층이 DLC 코팅에 미치는 영향)

  • Song, Jin-Soo;Nam, Tae-Woon
    • Corrosion Science and Technology
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    • v.10 no.2
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    • pp.65-70
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    • 2011
  • DLC is considered as the candidate material for application of moving parts in automotive components relatively in high pressure and temperature operating conditions for its high hardness with self lubrication and chemical inertness. The properties of interlayer between the substrate and the DLC film were studied. Arc ion plating method have been employed to deposit onto substrate and sputtering method was used for synthesizing DLC onto interlayer. Among these six types of interlayer, deposited DLC film onto TiCN showed excellent value for characteristics. From the results of analysis for physical properties of DLC films, it seems that the adhesion forces were more important factors than intrinsic mechanical properties such as hardness, roughness and wear resistance of DLC films. AFM(Atomic Force Microscope) was used for understanding roughness of DLC films. Hardnesses of the coating layers were identified by nano-indentation method and adhesions were checked by scratch method.