• Title/Summary/Keyword: gel materials

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Immunochemical Determination of Plant Constituents (1990년 제23회 학술발표회 논문초록)

  • 성철기
    • Journal of the Korean Society of Tobacco Science
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    • v.12 no.1
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    • pp.29-38
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    • 1990
  • Until relatively recently plant scientists have made little use of immunological techniques. Now, however, more and more researchers are discovering the powder of these techniques for the screening of immunomodulators and for the detection, quantitative determination and localization of compounds in plant materials. Especially, the recent developments in the fields of plant biotechnology and plant genetic engineering make it even more important for forkers in the plant sciences to become acquainted with the more sophisticated methods. The possible methods include onestep purification of antigens, visualization in situ by immunocytochemis try and on polyacrylam ids gel s by ni trocellulose Western blotting and quantification by various immunoassay. Among them, in this reviews, the quantitative determination methods are to be reviewed. There are several kinds of methods for the quantitative determination of plant constituents such as colorimetry, TLC, GLC, DCC, UV derivatization, densitometry and HPLC. When the complexity of plant constituents is considered. densitometry and HPLC have many advantages in sensitivity and separation ability. After a 11 some advarltages of two methods meritiorled above, all of these methods have many disadvantages and inconveniences. Previous purification for the application of all these methods make them less sensitive and more tedious. Immunoassay can solve these problems in part. But immunoassay also has some limitations. Specificity of immunoassay, contrary, can be considered to be disadvantages. Including this the advantages and disadvantages of immunoassay are to be discussed.

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Isolation of Escherichia coli O157:H7 from animal feces and biochemical characteristics of Verotoxin-2 produced by these strains I. Study on the phages related to production of Verotoxin-2, and Isolation of Escherichia coli O157:H7 from feces of cattle and pigs (동물분변에서 Escherichia coli O157:H7의 분리 및 이들 균이 생산하는 Verotoxin-2의 생물화학적 특성 I. 소와 돼지의 분변에서 E coli O157:H7의 분리 및 Verotoxin-2 생산에 관여하여 파아지의 분리에 관하여)

  • Cha, In-ho;Kim, Yong-hwan
    • Korean Journal of Veterinary Research
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    • v.36 no.2
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    • pp.371-378
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    • 1996
  • Three and 2 strains of E coli O157 were isolated from fecal materials of cattle (390) and pigs (420) in Korea, respectively. One strain of O157:H7 isolated from cattle and 2 strains of O157:H7 isolated from pigs were identified as verotoxin-1 (VT-1) produing strains and 2 strains (O157:H7 and O157:H-) isolated from cattle were identified as verotoxin-2 (VT-2) producing strains by neutralization test on HeLa and Vero cells. Culture supernatants of the isolates were cytotoxic to HeLa and Vero cells. The levels of cytotoxin produced by isolates were $10^2{\sim}10^4$ cytotoxic dose($CD_{50}$)/ml. Also, VT-2-converting bacteriophage was isolated from KSC109 strain which had been isolated from cattle. Molecular weight of the phage DNA was determined as approximately 45 Kb in 0.8% agarose gel electrophoresis, and morphology of the phage stained with phosphotungstic acid was observed by transmissible electron microscopy.

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Plasma Protein Adsorption to Anion Substituted Poly(vinyl alcohol) Membranes

  • Ryu, Kyu-Eun;Hyangshuk Rhim;Park, Chong-Won;Chun, Heung-Jae;Hong, Seung-Hwa;Kim, Jae-Jin;Lee, Young-Moo
    • Macromolecular Research
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    • v.11 no.6
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    • pp.451-457
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    • 2003
  • Anion-substituted poly(vinyl alcohol) (PVA) membranes, carboxymethylated PVA (C-PVA), and sulfonated PVA (S-PVA) were prepared and the effects of these substitutions on the plasma protein adsorption were studied by one- and two-dimensional gel electrophoresis and immunoblotting. When Cuprophane was used as a negative control, the amount of total proteins bound to samples decreased in the order Cuprophane > PVA > C-PVA > S-PVA, which we attribute to the effects of the surface characteristics of the samples, such as their surface tensions and electrostatic properties, on the adsorption of proteins to the surfaces of the materials. The results revealed that albumin was the most abundant protein in all the samples. The proportion of adsorbed fibrinogen to S-PVA exceeded those of PVA and C-PVA, whereas S-PVA exhibited the lowest IgG adsorption affinity among the samples we studied.

Preparation of Fine Silk Powder and It′s Application for Surface Modification (폐견사류의 미세분말화 및 표면 가공제 적용)

  • 이용우;이광길;여주홍;김종호
    • Journal of Sericultural and Entomological Science
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    • v.43 no.1
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    • pp.41-48
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    • 2001
  • The purification, dissolution and powdering of stained waste silk obtained from weaving and dyeing process were studied for the surface modification of textile fabric and plastic materials. The whiteness of stained waste silk could be improved through degumming and bleaching with sodium hydrosulfite. The water-soluble fibroin solution can be obtained by dissoving the degummed waste silk in a boiling solution of 50% calcium chloride for 60 minutes. The salts and heavy metals contained in fibroin solution were removed by electric dialysis, wool fiber filtration and gel filtration chromatography. The fibroin powder was prepared by using a fine grinder after the alkali treatment for weakening the silk fiber. The fine fibroin powder of particle size around 30 ㎛ was obtained with a ultra fine-mill, while it was finer below 10 ㎛ with a ball-mill. The dissolved or powdered silk was applied to the surface of fabric with addition of the binder (a urethane resin). The moisture content of polyester and nylon fabrics treated with the silk solution was improved due to hygroscopic property of silk. The fine fibroin powder mixed with the binder ws coated on the surface of synthetic film by use of the air pressed sprayer. It was revealed that the hygroscopicity as well as the softness of fibroin powder coated film was much improved. Therefore, it is thought that the fine silk fibroin powder is applicable as an coating agent for the surface modification of plastic and synthetic leather.

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The Weathering Resistance of Sol-Gel Derived Anti-Reflective SiO2-Tio2 Thin Films (졸-겔법에 의한 SiO2-Tio2계 박막의 내후성)

  • Kim, Sangmoon;Lim, Yongmu;Hwang, Kyuseog
    • Journal of Korean Ophthalmic Optics Society
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    • v.3 no.1
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    • pp.237-242
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    • 1998
  • A transparent and colorless $80SiO_2-20TiO_2$(mol%) thin films on soda-lime-silica slide glass and sapphire substrate were obtained by spin-coating technique using tetraethyl orthosilicate and titanium trichloride as starting materials. The prepared film annealed at $750^{\circ}C$ showed a high transmittance and a low reflectance. For the $SiO_2-TiO_2$ films on slide glasses, a strong interaction between the sodium ion and oxygens is properbly the origin of the good stability to the high temperature and the high humidity.

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Recombinant S-Layer Proteins of Lactobacillus brevis Mediating Antibody Adhesion to Calf Intestine Alleviated Neonatal Diarrhea Syndrome

  • Khang, Yong-Ho;Park, Hee-Young;Jeong, Yoo-Seok;Kim, Jung-Ae;Kim, Young-Hwan
    • Journal of Microbiology and Biotechnology
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    • v.19 no.5
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    • pp.511-519
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    • 2009
  • A chimeric gene encoding enhanced green fluorescent protein (EGFP) and a S-layer protein from Lactobacillus brevis KCTC3102, and/or two copies of the Fe-binding Z-domain, a synthetic analog of the B-domain of protein A, was constructed and expressed in Escherichia coli BL21(DE3). The S-layer fusion proteins produced in a 500-1 fermentor were likely to be stable in the range of pH 5 to 8 and $0^{\circ}C$ to $40^{\circ}C$. Their adhesive property enabled an easy and rapid immobilization of enzymes or antibodies on solid materials such as plastics, glass, sol-gel films, and intestinal epithelial cells. Owing to their affinity towards intestinal cells and immunoglobulin G, the S-layer fusion proteins enabled the adhesion of antibodies to human epithelial cells. In addition, feeding a mixture of the S-layer fusion proteins and antibodies against neonatal calf diarrhea (coronavirus, rotavirus, Escherichia coli, and Salmonella typhimurium) to Hanwoo calves resulted in 100% prevention of neonatal calf diarrhea syndrome (p<0.01), whereas feeding antibodies only resulted in 56% prevention.

Selective Crystallization of SAPO-5 and SAPO-34 Molecular Sieves in Alkaline Condition: Effect of Heating Method

  • Yoon, Ji-Woong;Jhung, Sung-Hwa;Kim, Young-Ho;Park, Sang-Eon;Chang, Jong-San
    • Bulletin of the Korean Chemical Society
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    • v.26 no.4
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    • pp.558-562
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    • 2005
  • Crystallization of SAPO-5 and SAPO-34 molecular sieves with microwave and conventional electric heating of the same gel has been investigated in an alkaline condition using N,N,N’N’tetraethylethylenediamine as a template molecule. SAPO-5 structure can be selectively prepared with microwave heating because of the fast crystallization of the technique. On the other hand, SAPO-34 is the sole product with usual conventional electric heating because SAPO-5 can be gradually transformed into SAPO-34 structure with an increase in crystallization time. This phase selectivity is probably because of the relative stability of the two phases at the reaction conditions (kinetic effect). Crystallization with microwave heating can be suggested as a phase selective synthesis method for relatively unstable materials because of fast crystallization.

Development of $YSZ/La_0.85S_r0.15MnO_3$ Composite Electrodes for Solid Oxide Fuel Cells (고체산화물 연료전지용 $YSZ/La_0.85S_r0.15MnO_3$계 복합전극의 개발)

  • 윤성필;현상훈;김승구;남석우;홍성안
    • Journal of the Korean Ceramic Society
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    • v.36 no.9
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    • pp.982-990
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    • 1999
  • YSZ/LSM composite cathode was fabricated by dip-coating of YSZ sol on the internal pore surface of a LSM cathode followed by sintering at low temperature (800-100$0^{\circ}C$) The YSZ coating significantly increased the TPB(Triple Phase Boundary) where the gas the electrode and the electrolyte were in contact with each other. Sinter the formation of resistive materials such as La2Zr2O7 or SrZrO3 was prevented due to the low processing temperature and TPB was increased due to the YSZ film coating the electrode resistance (Rel) was reduced about 100 times compared to non-modified cathode. From the analysis of a.c impedance it was shown that microstructural change of the cathode caused by YSZ film coating affected the oxygen reduction reaction. In the case of non-modified cathode the RDS (rate determining step) was electrode reactions rather than mass transfer or the oxygen gas diffusion in the experimental conditions employed in this study ($600^{\circ}C$-100$0^{\circ}C$ and 0,01-1 atm of Po2) for the YSZ film coated cathode however the RDS involved the oxygen diffusion through micropores of YSZ film at high temperature of 950-100$0^{\circ}C$ and low oxygen partial pressure of 0.01-0.03 atm.

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Dielectric Properties of Zr-doped (Ba,Sr,Ca)TiO3 Thick Films for Microwave Phase Shifters

  • Lee, Sung-Gap;Lee, Sang-Heon
    • Transactions on Electrical and Electronic Materials
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    • v.4 no.2
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    • pp.24-28
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    • 2003
  • (Ba,Sr,Ca)TiO$_3$ powders, prepared by the sol-gel method, were mixed with organic binder and the BSCT thick films were fabricated by the screen printing techniques on alumina substrates. All the BSCT thick films, sintered at 1420$^{\circ}C$, showed the typical XRD patterns of a perovskite polycrystalline structure. The average grain sizes decreased with increasing amounts of ZrO$_2$, and the BSCT(40/40/20) thick films doped with 2wt% MnO$_2$ showed a value of 8$\mu\textrm{m}$. The thickness of thick films by four-cycle on printing/drying was approximately 951$\mu\textrm{m}$. The relative dielectric constant decreased with increasing Ca content and MnO$_2$ doping amount. The relative dielectric constant, dielectric loss and tunability of the BSCT(50/40/10) thick films doped with 2.0wt% ZrO$_2$ were 772, 0.184% and 15.62%, respectively.

The Electrochemical Performance of Li3V2(PO4)3/Graphene Nano-powder Composites as Cathode Material for Li-ion Batteries

  • Choi, Mansoo;Kim, Hyun-Soo;Lee, Young Moo;Jin, Bong-Soo
    • Journal of Electrochemical Science and Technology
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    • v.5 no.4
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    • pp.109-114
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    • 2014
  • The $Li_3V_2(PO_4)_3$/graphene nano-particles composite was successfully synthesized by a facile sol-gel method. The addition of a graphene in $Li_3V_2(PO_4)_3(LVP)$(LVP) showed the high crystallinity and influenced the morphology of the $Li_3V_2(PO_4)_3$ particles observed in X-ray diffraction (XRD) and scanning electron microscopy (SEM). The LVP/graphene samples were well connected, resulting in fast charge transfer. The effect of the addition graphene nano-particles on electrochemical performance of the materials was investigated. Compared with the pristine LVP, the LVP/graphene composite delivered a higher discharge capacity of $122mAh\;g^{-1}$ at 0.1 C-rate, better rate capability and cyclability in the potential range of 3.0-4.3 V. The electrochemical impedance spectra (EIS) measurement showed the improved electronic conductivity for the LVP/graphene composite, which can ensure the high specific capacity and rate capability.