http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Doug Youn Lee (검색결과 39 건)
- 무료
- 기관 내 무료
- 유료
-
바륨 페라이트를 함유한 알지네이트 자성 복합 입자의 제조
이덕연,오영일,김동현,김광만,김경남,이용근 大韓齒科器材學會 2004 대한치과재료학회지 Vol.31 No.1
Magnetic polymer composite materials with high coercivity have potential applications in medical diagnostic technologies, magnetic drug delivery, and hyperthermic cancer treatment. The purpose of this study was to prepare the magnetic composite particles by encapsulating barium ferrite powders with alginate and to investigate their physical and biological properties. 0.4 g of sodium alginate was dissolved in 20 ml of distilled water and different amount (0.4~4 g) of barium ferrite powder was dispersed in alginate solution using an ultrasonication method. The resulting barium ferrite-alginate slurry was added dropwise to a CaCl2 solution to form magnetic Ca-alginate composite beads. They were separated by filtration and washed several times with water and ethanol. The final product was then completely dried at 40℃ under vacuum to obtain brownish black powders (0.1~1 mm in size) with a high magnetic response when submitted to a small magnet. Average size of magnetic composite particles was dependent on the amount of barium ferrite and the viscosity of slurry . The morphological and dimensional analyses of magnetic composite particles were performed by optical microscopy and scanning electron microscopy. Magnetic polymer composite particle was found to maintain the high coercivity. The saturation magnetization value for magnetic Ca-alginate composites increased with the increase of the barium ferrite/alginate ratio. The amount of self-heating induced by hysteresis under an alternating magnetic field was measured as a function of barium ferrite/alginate ratio in distilled water. According to the results, the encapsulated magnetic composite is expected to be useful for hyperthermia and chemotherapy remarkably.
-
부가중합형 실리콘 인상재의 표면 친수성이 미세부 재현성에 미치는 영향
오영일,황수영,이덕연,김경남,김광만 大韓齒科器材學會 2003 대한치과재료학회지 Vol.30 No.3
The purpose of this study was to investigate the relationship between surface hydrophilicity and detail reproducibility of die stone for hydrophilic polyvinyl siloxane impression materials modified with nonionic surfactants. Hydrophilic polyvinyl siloxane impression materials were prepared with a polydimethylsiloxane composition and nonionic surfactants. The surfactants used were nonylphenoxy poly(ethyleneoxy) ethanol homologs of varying ethyleneoxy chain length. These homologs are designated NP4, NP6, and NPIO according to the mole number of ethyleneoxy group of 4, 6, and 10, respectively. The contact angle, consistency, and detail reproducibility for hydrophilic polyvinyl siloxane impression materials were tested. The incorporation of nonionic surfactant into polyvinyl siloxanes enhanced their hydrophilicity and consequently led to significant reduction in contact angles. Significant differences in contact angle were found among the samples (P < 0.05). The contact angle was lowest when NP4 was incorporated even though NP4 is less hydrophilic than NP6 and P1O. This implies that the exposed surfactant concentration on the surface was highest when NP4 was used. The consistency of surfactant-modified silicone impression materials were not affected by the type of surfactants used in this study. However, NP4-modified polyvinyl siloxane impression material showed the highest quality reproduction of the thinnest line, indicating highest wettability with gypsum among the samples. In conclusion, the surface concentration of surfactant on the silicone impression material was a crucial factor in determining wettability. The suface hydrophilicity of surfactant-modified silicone impression materials was of major relevance to the detail reproduction of die stone.
-
Lee, Sang-Bae,Lee, Doug-Youn,Lee, Yong-Keun,Kim, Kyoung-Nam,Choi, Seong-Ho,Kim, Kwang-Mahn John Wiley Sons, Ltd. 2008 Surface and interface analysis Vol.40 No.3
<P>There are several considerations when choosing a barrier membrane for use with guided tissue regeneration (GTR) to treat periodontal diseases: biocompatibility, cell-occlusiveness, space-maintaining ability, tissue integration, and clinical manageability can all affect success. Our laboratory developed drug-releasing and space-maintaining membranes for use with GTR to provide effective periodontal therapy. Tetracycline is used in periodontal therapy because of its antibacterial activity and because it enhances tissue regeneration by increasing osteoblast and anticollagenolytic activity. Here, tetracycline-containing solutions of the polymers poly(L-lactide), poly(L-lactide-co-glycolide), and poly(glycolide-co-caprolactone) were used to coat collagen sponges using a spray-coating technique. The surface structure and morphology of the prepared membranes were characterized and the drug release, antibacterial effect, and mechanical properties were evaluated. All membranes comprised double layers: a dense coated layer and a collagen layer. The collagen layer had a porous surface and interconnected pores. In contrast, the coated layer was a thin film without pores and had a low concentration of polymer. This biodegradable, polymer-coated collagen membrane retained its drug release properties as well as antibacterial effect and had better mechanical integrity than uncoated collagen sponge. Taken together, these results suggest that tetracycline-loaded membranes might enhance GTR efficacy. Copyright © 2008 John Wiley & Sons, Ltd.</P>
-
-
Physical and Adhesive Properties of Cyanoacrylate-Based β-TCP Composites
Lee, G.S.,Lee, Sang Bae,Lee, Doug Youn,Park, Kyeong Jun,Kim, S.O.,Kim, Kyoung Nam,Choi, B.J. Trans Tech Publications, Ltd. 2007 Key engineering materials Vol.330 No.-
<P>Histoacryl® (N-butyl-2-cyanoacrylate) has been widely utilized as a tissue adhesive. The aim of this study was to evaluate the physical and adhesive properties of newly developed cyanoacrylate-based β-TCP composite systems. The β-TCP powder was modified on the surface with citric acid to make this material mixed with cyanoacrylate easily. The setting time of acidtreated β-TCP/ Histoacryl® systems was dramatically prolonged and the polymerization heat was significantly decreased compared to that of untreated β-TCP/Histoacryl® system. The shear bond strength of cyanoacrylate-based β-TCP composites decreased with addition of acid-treated β-TCP filler. The compressive strength of β-TCP/Histoacryl® composites increased strongly with increasing the amount of acid-treated β-TCP filler. The cytotoxicity of the β-TCP/Histoacryl® composites decreased with the increasing of the amount of added β-TCP. These results indicated that our novel β-TCP/Histoacryl® composites had the great potential to serve as adhesives or filling materials in the dental field.</P>
-
-
-
-
-
RISS
DBpia연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
