• Title/Summary/Keyword: biomaterial

Search Result 685, Processing Time 0.038 seconds

Theoretical Framework For Describing Strain Energy Function on Biomaterial (생체재료를 설명하는 스트레인 에너지 함수에 대한 이론적 고찰)

  • Kang, Taewon
    • Journal of the Korean Society of Manufacturing Technology Engineers
    • /
    • v.22 no.1
    • /
    • pp.50-55
    • /
    • 2013
  • In order to understand the biomaterial like the blood vessel of artery, there is a need to quantify the biomechanical behavior of the vessel. However, theoretical framework to describe and quantify the behaviour of blood vessel was not well established so far. For studying the biomechanical behavior of artery, Rubber-liked material which is similar to passive artery is selected since conventional theoretical interpretation is very limited to understand and predict the behavior of biomaterial. Rubber-like material is assumed to be very similar to artery and has properties of isotropy, homogeneity and is undergoing large deformation. Based on this assumption, stress developed on Rubber-like material is described by strain energy function and strain invariants which are required to understand the nonlinear elastic behavior of biomaterial. The descriptor which would be used for understanding the biomechanical behavior of artery is studied in this work.

Factors Affecting the Rate of Release of 5-Fluorouracil from Ethylene-Vinyl Acetate Matrices

  • Oh, Seaung-Youl;Chung, Hee-Won;Cho, Sun-Hang;Lee, Hai-Bang
    • Journal of Pharmaceutical Investigation
    • /
    • v.24 no.3
    • /
    • pp.33-39
    • /
    • 1994
  • We have studied the effect of loading amount and particle size on the rate of release of 5-fluorouracil (5-FU) from ethylene-vinyl acetate (EVA) matrix. Release rate increased as the loading amount and particle size increase. We also studied the effect of additives (lactose and algin) on the rate of release of 5-FU. Both algin and lactose promoted the rate of release. The ability to increase the rate is in the order of algin>lactose>5-FU. Scanning electron microscope study clearly shows that large cavities and cracks are created. The results imply that, by the proper combinations of the amount of the additive, $EVA_c$ and drug, the rate of drug release can be modulated over a wide range of values.

  • PDF

Isolation and Characterization of Marine Bacterial Strain Degrading Fucoidan from Korean Undaria pinnatifida Sporophylls

  • Kim, Woo-Jung;Kim, Sung-Min;Lee, Yoon-Hee;Kim, Hyun-Guell;Kim, Hyung-Kwon;Moon, Seong-Hoon;Suh, Hyun-Hyo;Jang, Ki-Hyo;Park, Yong-Il
    • Journal of Microbiology and Biotechnology
    • /
    • v.18 no.4
    • /
    • pp.616-623
    • /
    • 2008
  • In spite of an increasing interest in fucoidans as biologically active compounds, no convenient commercial sources with fucoidanase activity are yet available. A marine bacterial strain that showed confluent growth on a minimal medium containing fucoidan, prepared from Korean Undaria pinnatifida sporophylls, as the sole carbon source was isolated and identified based on a 16S rDNA sequence analysis as a strain of Sphingomonas paucimobilis, and named Sphingomonas paucimobilis PF-1. The strain depolymerized fucoidan into more than 7 distinct low-molecular-mass fucose-containing oligosaccharides, ranging from 305 to 3,749 Da. The enzyme activity was shown to be associated with the whole cell, suggesting the possibility of a surface display of the enzyme. However, a whole-cell enzyme preparation neither released the monomer L-fucose from the fucoidan nor hydrolyzed the chromogenic substrate p-nitrophenyl-${\alpha}$-L-fucoside, indicating that the enzyme may be an endo-acting fucoidanase rather than an ${\alpha}$-L-fucosidase. Therefore, this would appear to be the first report on fucoidanolytic activity by a Sphingomonas species and also the first report on the enzymatic degradation of the Korean Undaria pinnatifida sporophyll fucoidan. Moreover, this enzyme activity may be very useful for structural analyses of fucose-containing polysaccharides and the production of bioactive fucooligosaccharides.

Preparation and Surface-Active Properties of Vinyl Acetate Cotelomers (I) (비닐아세테이트 코텔로머의 제조 및 계면활성(I))

  • Lee, Eon-Pil;Kang, Se-Mi;Hwang, Dae-Youn;Jung, Young-Jin;Choi, Hae-Wook;Choi, Young-Ho;Lee, Jae-Ho
    • Fashion & Textile Research Journal
    • /
    • v.14 no.4
    • /
    • pp.677-683
    • /
    • 2012
  • 1-octanethiol and vinyl acetate telomers ($R_8S$-nVAc) were synthesized and hydrolyzed with sodium hydroxide subsequently, 1.2-epoxyhexane was then introduced to the telomers. In addition, we prepared cotelomers of multi-alkylated nonionic surfactants with a molecular structure of xRnMA-yVA (x; hydrophobic group, y; hydrophilic group, MA; methacrylic ester, VA; vinyl alcohol, R; and alkyl group) and cross-linked with sodium tetraborate decahydrate. Their active surface properties were investigated by several techniques such as surface tension, foaming property, and emulsification power measurements. The surface tension of $R_8S$-8.8VA decreased without the introduction of 1.2-Epoxy hexane, and the degree of emulsification and foaming abilities of $R_8S$-8.8VA increased without the introduction of 1.2-Epoxy hexane. However, the differences were insignificant. The epoxy groups were attached to a $R_8S$-8.8VA cotelomer with a limited variation of the active surface properties. The surface tension of $1.1R_6MA$-8.8VA decreased after cross-linking subsequently, the degree of emulsification and foaming abilities of $1.1R_6MA$-8.8VA increased after cross-linking. However, there was no clear difference between them. The B-O bonds were attached to a $1.1R_6MA$-8.8VA cotelomer with a limited variation of the active surface properties.

Development of a Monitoring Vector for Leuconostoc mesenteroides Using the Green Fluorescent Protein Gene

  • Lee, Kwan-Hoon;Park, Woo-Jung;Kim, Joo-Yun;Kim, Han-Geun;Lee, Jung-Min;Kim, Jeong-Hwan;Park, Jeong-Woo;Lee, Jong-Hoon;Chung, Sung-Kyun;Chung, Dae-Kyun
    • Journal of Microbiology and Biotechnology
    • /
    • v.17 no.7
    • /
    • pp.1213-1216
    • /
    • 2007
  • The vector pCW5 with plasmid pC7, originally isolated in Lactobacillus paraplantarum C7 derived from kimchi, was constructed using a p32 strong promoter, the pC7 replicon, and green fluorescent protein (GFP) as the reporter. The constructed vector was transformed into E. coli and Leuconostoc mesenteroides, and GFP expression detected using a Western blot analysis. GFP fluorescence was recognized in E. coli and Leuconostoc mesenteroides using a confocal microscope. In addition, GFP fluorescence was also clearly detected in several industrially important lactic acid bacteria (LAB), including Lactobacillus bulgaricus, Lactobacillus paraplantarum, and Lactobacillus plantarum. Thus, pCW5 was shown to be effective for Leuconostoc mesenteroides when using GFP as the reporter, and it can also be used as a broad-host-range vector for other lactic acid bacteria.

Prediction and Annotation of ABC Transporter Genes from Magnaporthe oryzae Genome Sequence (벼도열병균 게놈서열로부터 ABC transporter 유전자군의 예측 및 특성 분석)

  • Kim, Yong-Nam;Kim, Jin-Soo;Kim, Su-Young;Kim, Jeong-Hwan;Lee, Jong-Hwan;Choi, Woo-Bong
    • Journal of Life Science
    • /
    • v.20 no.2
    • /
    • pp.176-182
    • /
    • 2010
  • Magnaporthe oryzae is destructive plant-pathogenic fungus and causes rice blast. The pathogen uses several mechanisms to circumvent the inhibitory actions of fungicides. ATP-binding cassette (ABC) transporters are known to provide protection against toxic compounds in the environment. PC facilitated bioinformatic analysis, particularly with respect to accessing and extracting database information and domain identification. We predicted ABC transporter genes from the M. oryzae genome sequence with computation and bioinformatics tools. A total of thirty three genes were predicted to encode ABC transporters. Three of thirty three putative genes corresponded to three known ABC transporter genes (ABC1, ABC2 and ABC3). Copy numbers of the ABC transporter genes were proven by Southern blot analysis, which revealed that twenty genes tested exist as a single copy. We amplified the DNA complementary to RNA corresponding to eleven of these by reverse transcriptase polymerase chain reaction.