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        검색결과 128

        61.
        2008.09 구독 인증기관 무료, 개인회원 유료
        Thrombospondins (TSP-1, TSP-2) are secretory extracellular glycoproteins that are involved in a variety of physiological processes such as tumor cell adhesion, invasion, and metastasis. The present study was undertaken to elucidate the involvement of thrombospondins in the adhesion of osteoblast-like cells using the TSP-1 or TSP-2 antisense MG63 and MC3T3-E1 cell lines. For downregulation of TSPs expression, we prepared antisense constructs for TSP-1 and TSP-2 using the pREP4 an episomal mammalian expression vector, which be able to produce the specific antisense oligonucleotides around chromosome. MG63 and MC3T3-E1 osteoblast-like cells were transfected with the antisense constructs and nonliposomal Fugene 6, and then selected under hygromycin B (50 μM/mℓ) treatment for 2 weeks. Western blot analysis revealed that expression of the TSP proteins was downregulated in the antisense cell lines. The cell adhesion assay showed that adhesive properties of TSP-1 and TSP-2 antisense MG63 cells on the polystyrene culture plate were reduced to 17% and 21% of the control cells, respectively, and those of the TSP-1 and TSP-2 antisense MC3T3-E1 cells also decreased to 19% and 27% of control, respectively. Adhesion of TSP-1 and TSP-2 antisense MC3T3-E1 cells on Type I collagen-coated culture plate decreased to 27% and 76%, respectively. These results indicate that TSP-1 and TSP-2 proteins may have an important role in adhesion of osteoblast-like cells to extracellular matrix.
        4,000원
        62.
        2008.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The effect of annealing treatment conditions on the interfacial adhesion energy between electrolessplated Ni film and polyimide substrate was evaluated using a 180˚ peel test. Measured peel strength values are 26.9±0.8, 22.4±0.8, 21.9±1.5, 23.1±1.3, 16.1±2.0 and 14.3±1.3g/mm for annealing treatment times during 0, 1, 3, 5, 10, and 20 hours, respectively, at 200˚C in ambient environment. XPS and AES analysis results on peeled surfaces clearly reveal that the peeling occurs cohesively inside polyimide. This implies a degradation of polyimide structure due to oxygen diffusion through interface between Ni and polyimide, which is also closely related to the decrease in the interfacial adhesion energy due to thermal treatment in ambient conditions.
        4,000원
        63.
        2008.05 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The effects of the field emission property in relation to the surface morphology and adhesion force were investigated. The single-wall-nanotube-based cathode was obtained by use of an in-situ arc discharge synthesis method, a screen-printing method and a spray method. The morphologies of the formed emitter layers were very different. The emission stability and uniformity were dramatically improved by employing an in-situ arc discharge synthesis method. In this study, it was confirmed that the current stability and uniformity of the field emission of the cathode depend on the surface morphology and adhesion force of the emitters. The current stability of the field emission device was also studied through an electrical aging process by varying the current and electric field.
        4,000원
        64.
        2008.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        1.5 μm-thick copper films deposited on silicon wafers were successfully bonded at 415˚C/25 kN for 40 minutes in a thermo-compression bonding method that did not involve a pre-cleaning or pre-annealing process. The original copper bonding interface disappeared and showed a homogeneous microstructure with few voids at the original bonding interface. Quantitative interfacial adhesion energies were greater than 10.4 J/m2 as measured via a four-point bending test. Post-bonding annealing at a temperature that was less than 300˚C had only a slight effect on the bonding energy, whereas an oxygen environment significantly deteriorated the bonding energy over 400˚C. This was most likely due to the fast growth of brittle interfacial oxides. Therefore, the annealing environment and temperature conditions greatly affect the interfacial bonding energy and reliability in Cu-Cu bonded wafer stacks.
        4,000원
        65.
        2007.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        According to progress rapidly digitalization, networked and mobilization of electronics industry, there are demands for being smaller, thinner, more light, and more efficient complex functions of electronic devices which are wireless devices, semi-conductors, packages and mobile devices. Therefore, the solder resist on a printed circuit board have been required with the high resolution and the eco-friendly materials in the surface treatments such as high heating process and coating process with electrolysis. In this study, the photoinitiator initiator and monomers of the solder resist were prepared with their contents for reducing the occurrence of the under-cut. We investigated the sample surface by UV/VIS spectrometer, FT-IR, OM after HASL and ENIG process. From our results, it is possible to get a high adhesion of resist with optimal contents between the photoinitiator initiator and monomers after surface treatments.
        4,000원
        66.
        2007.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The magnetron sputtering was used to deposit Ni buffer layers on the polyimide surfaces to increase the adhesion strength between Cu thin films and polyimide as well as to prevent Cu diffusion into the polyimide. The Ni layer thickness was varied from 100 to 400Å. The adhesion strength increased rather significantly up to 200Å of Ni thickness, however, there was no significant increase in strength over 200Å. The XPS analysis revealed that Ni thin films could increase the adhesion strength by reacting with the polar C=O bonds on the polyimide surface and also it could prevent Cu diffusion into the polyimide. The Cu/Ni/ polyimide multilayer thin films showed a high stability even at the high heating temperature of 200˚C, however, at the temperature of 300˚C, Cu diffused through the Ni buffer layer into polyimide, resulting in the drastic decrease in adhesion strength.
        4,000원
        68.
        2007.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Sodium carboxymethylcellulose(SCMC)와 Hyaluronic acid(HA)가 수정란 이식 및 채란을 위한 복강 수술 후 생식기의 유착 방지 효과 여부를 확인하기 위하여 본 실험을 수행하였다. 실험 동물로 성숙한 암컷 한국 흑염소 20두를 대조군, saline 투여군, SCMC 1%, SCMC 2% 및 HA 0.4% 투여군에 각각 4마리씩 배치하였다. 수정란 채취를 위한 통상적인 방법의 수술을 시행한 후 약물 주입용 카테터를 절
        4,000원
        69.
        2007.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Kevlar was chemically surface modified with resorcinol-formaldehyde(RF) prepolymer and VP rubber latex for application to high strength tirecords. RF prepolymer was easily obtained by polymerization at room temperature in the presence of a base catalyst. The mechanical and thermal properties of Kevlar were not significantly changed during surface treated under various conditions. The change of adhesion with rubber were investigated through H-test method. Maximum increase of adhesion force between rubber and Kevlar was obtained up to 40% than that of untreated one when the fiber was soaked in RFL dipping solution and thermally treated at 170℃ for 3 - 5min.
        4,000원
        73.
        2006.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The brazing adhesion properties of Ag coated W-Ag electric contact on the Cu substrate have been investigated in therms of microstructure, phase equilibrium and adhesion strength. Precoating of Ag layer ( in thickness) on the contact material was done by electro-plating method. Subsequently the brazing treatment was conducted by inserting BCuP-5 filler metal (Ag-Cu-P alloy) layer between Ag coated W-Ag and Cu substrate and annealing at in atmosphere. The optimum brazing temperature of was semi-empirically calculated on the basis of the Cu atomic diffusion profile in Ag layer of commercial electric contact produced by the same brazing process. As a mechanical test of the electric contact after brazing treatment the adhesion strength between the electric contact and Cu substrate was measured using Instron. The microstructure and phase equilibrium study revealed that the sound interlayer structure was formed by relatively low brazing treatment at . Thin Ag electro-plated layer precoated on the electric contact ( in thickness) is thought to be enough for high adhesion strength arid sound microstructure in interface layer.
        4,000원
        75.
        2005.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 히알루론산나트륨/카르복시메틸셀룰로오스나트륨(HA/CMC)으로 구성된 유착방지 막을 제조하였고, 쥐에서 유착방지용에 대한 효과를 평가하였다. 유착방지 막은 HA/CMC 용액을 동결건조한 후 1-에틸-3-(3-디메틸아미노프로필)카보디이미드 (EDAC)로 가교하여 제조하였다. Sprague-Dawley쥐의 맹장/복벽 찰과상 모델에서 복부 중앙선 절개 후 장막과 복벽을 bone burr로 1×2;(cm2) 크기로 찰과상을 만들고, 상처 면 주위의 3곳을 봉합사로 고정시켰다. 상처난 장을 실험군의 경우 HA/CMC 막으로 덮어주었으며, 대조군은 아무처치도 하지 않은 상태로 복벽을 마주보게 하였다. 대조군의 대부분은 수술 후 7, 14, 21, 28일에 유착정도 3 이상을 나타내었고, 반면 실험군의 60~70%는 수술 후 14, 21, 28일에 유착정도 2 이하를 나타내었다. 이는 유착세기에서도 유사하였다. 일반적으로 유착정도와 유착세기는 수술 후 14일까지 점차 증가하였고, 수술 후 21일에는 거의 동일하거나 약간 증가하였으며, 28일째에는 감소하였다. 대조군은 유착정도와 유착세기, 유착면적에서 높은 수치를 나타내었다. 이 유착방지막은 수술 후 유착방지에서 좋은 임상결과를 나타낼 수 있을 것으로 기대된다.
        4,200원
        77.
        2005.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Removable protective adhesives for automobiles were synthesized by an emulsion polymerization of monomers such as n-butyl acrylate (BA), n-butyl methacrylate (BMA), acrylonitrile (AN), acrylic acid (AA) and 2-hydroxyethyl methacrylate (2-HEMA), in which AA and 2-HEMA were functional monomers. Potassium persulfate (KPS) was used as an initiator and sodium lauryl sulfate (SLS) was used as an emulsifier, and polyvinyl alcohol (PVA) was used as a stabilizer. Emulsion polymerization was carried out in a semi-batch type reactor. Tensile strength, extension, peel strength, viscosity and solid content of the synthesized adhesives were tested. The optimum physical properties of the removable protective adhesives for automobiles were obtained with the composition of 0.43 mole BA, 0.57 mole AN, 0.21 mole BMA, 0.03 mole AA, and 0.03 mole 2-HEMA.
        4,000원
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