• Title/Summary/Keyword: poly(I:C)

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A Study on the Reliability of Ru-Zr Metal Gate with Thin Gate Oxide (박막 게이트 산화막에 대한 Ru-Zr 금속 게이트의 신뢰성에 관한 연구)

  • 이충근;서현상;홍신남
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.53 no.4
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    • pp.208-212
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    • 2004
  • In this paper, the characteristics of co-sputtered Ru-Zr metal alloy as gate electrode of MOS capacitors have been investigated. The atomic compositions of alloy were varied by using the combinations of relative sputtering power of Ru and .Zr. C-V and I-Vcharacteristics of MOS capacitors were measured to find the effective oxide thickness and work function. The alloy made of about 50% of Ru and 50% of Zr exhibited an adequate work function for nMOS. C-V and I-V measurements after 600 and $700^{\circ}C$ rapid thermal annealing were performed to prove the thermal and chemical stability of the Ru-Zr alloy film. Negligible changes in the accumulated capacitance and work function before and after annealing were observed. Sheet resistance of Ru-Zr alloy was lower than that of poly-silicon. It can be concluded that the Ru-Zr alloy can be a possible substitute for the poly-silicon used as a gate of nMOS.

Production and Evaluation of Immunoreactivity of Poly Lysine-Tagged Single Chain Fragment Variable (ScFv) Lym-1 Antibody for Direct Conjugation to Fluorescence Dye (형광 물질 직접 표지를 위한 Poly Lysine 도입 Lym-1 단일사슬 항체의 제조 및 면역반응성 평가)

  • Jung, Jae-Ho;Choi, Tae-Hyun;Woo, Kwang-Sun;Chung, Wee-Sup;Kang, Joo-Hyun;Jeong, Su-Young;Choi, Chang-Woon;Lim, Sang-Moo;Cheon, Gi-Jeong
    • Nuclear Medicine and Molecular Imaging
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    • v.43 no.5
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    • pp.487-494
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    • 2009
  • Purpose: Small size of recombinant scFv antibody has many advantages such as rapid blood clearances and improved targeting antibodies to tumor region. On the other hand owing to small size, number of amino group is insufficient in conjugation with chelator and fluorescence labeling. This study is to introduce poly lysine tag to the C-terminal end of scFv lym-1 sequence for fluorescence chelator conjugation. Materials and Methods: Poly lysine scFv lym-1 gene, cloned into pET-22b (+) vector, was expressed in E. coli BL21 (DE3) strain. Antibody purification was performed with Ni-NTA column and then size exclusion column chromatography. Expression and purification levels of poly lysine tagged scFv lym-1 antibody were confirmed by western blot analysis. I-124, I-125, I-131 and Tc-99m were used for radiolabeling of purified poly lysine scFv lym-1. Flow cytometry analysis of FIT( conjugated poly lysine scFv lym-1 was performed for confirmation of immunoreactivity of human Burkitt's lymphoma cells. Results: Poly lysine scFv lym-1 antibody was purified through two steps and identified as molecular weight of 48 KDa. Radiolabeling yields of I-124, I-125, I-131 and Tc-99m into poly lysine scFv lym-1 were >99%, >99%, >95% and >99%, respectively. Flow cytometry analysis of poly lysine scFv and scFv lym-1 was showed similar immunoreactivity to human Burkitt's lymphoma cells. Conclusion: Poly lysine tag was useful for the sufficient number of amino groups to scFv lym-1 antibody for chelator conjugation with minimizing loss of immunoreactivity.

Synthesis and Characterization of Biocompatible and Biodegradable Polyesters (II):Crystallization and Biodegradation of Poly (1,4-butanediol succinate) (생체적합성과 생분해성을 갖는 폴리에스테르 중합체의 합성과 특성에 관한 연구(II) : Poly(1, 4-butanediol succinate)의 결정화 및 생분해성)

  • 송대경;성정석
    • Journal of Biomedical Engineering Research
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    • v.16 no.1
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    • pp.9-16
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    • 1995
  • Biodegradable poly (I ,4-butanediol succinate) (PBS) was synthesized from 1,4-butanediol and succinic anhydride. The glass transition temperature of poly (I, 4-butanediol succinate) was revealed at $73^{\circ}C$. The crystallization and cold crystallization of the polymers were investigated as a function of holding time in melt state, cooling rate. reheating, and molecular weight. Chain scission and/or cmsslinking did not occur in the melt state at var.ious holding times. Slower scanning rate can allow more times for nucleation, rearrangement, and packing of the polymer chain, so the onset temperature of crystallization from the melt was increased. PBS crystallized from the melt was found to have spherulitic structure. The degradation behavior of PBS was studied under basic conditions and with microorganisms using the modified ASTM method. In the basic solution. PBS lost up to 85% of its mass within two days. Based upon visual observation, the crystalline structure of films composed of larger molecular weight polymers retained their crystallinity longer than similar structures in low molecular weight samples.

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Preparation of Proton Conducting Anhydrous Membranes Using Poly(vinyl chloride) Comb-like Copolymer (Poly(vinyl chloride) 빗살형 공중합체를 이용한 무가습 수소이온 전도성 전해질막의 제조)

  • Kim, Jong-Hak;Koh, Joo-Hwan;Seo, Jin-Ah;Ahn, Sung-Hoon;Zeng, Xiaolei
    • Membrane Journal
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    • v.19 no.2
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    • pp.89-95
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    • 2009
  • A comb-like copolymer consisting of a poly(vinyl chloride) backbone and poly(hydroxy ethyl acrylate) side chains, i.e. PVC-g-PHEA, was synthesized through atom transfer radical polymerization (ATRP). This comb-like copolymer was crosslinked with 4,5-imidazole dicarboxylic acid (IDA) via the esterification of the -OH groups of PHEA in the graft copolymer and the -COOH groups of IDA. Upon doping with phosphoric acid (PA, $H_3PO_4$) to form imidazole-PA complexes, the proton conductivity of the membranes continuously increased with increasing PA content. A maximum proton conductivity of 0.011 S/cm was achieved at $100^{\circ}C$ under anhydrous conditions. The PVC-g-PHEA/IDA/PA complex membranes exhibited good mechanical properties, i.e. 575 MPa of Young's modulus, as determined by a universal testing machine (UTM). Thermal gravimetric analysis (TGA) shows that the membranes were thermally stable up to $200^{\circ}C$.

Interaction between Poly(vinylpyrrolidone) and Ionic Dyes in Aqueous Solution System (I)

  • Lee, Sangchul;Kim, Heain;Park, Soomin
    • Textile Coloration and Finishing
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    • v.24 no.4
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    • pp.239-246
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    • 2012
  • The binding isotherms of ionic dyes with Poly(vinylpyrrolidone) in aqueous solution were determined by the dynamic dialysis technique. The shape of the isotherms of cationic dye, C. I. Basic Red 18 with poly(vinlypyrrolidone) showed a partition type. It suggests that the binding involves a non-cooperative mode. Isotherms of an anion dye, a synthesized dye by coupling of diazotized m-trifluoromethylaniline with 2-naphthol-6-sulfonic acid, were sigmoid type and showed multimode interaction. The results were interpreted by the McGhee von Hippel theory. The thermodynamic parameters for the complex formation of the dyes-polymer were calculated from their temperature dependences of the intrinsic binding constant.

Characterization of Mud Loach (Misgurnus mizolepis) Apolipoprotein A-I: cDNA Cloning, Molecular Phylogeny and Expression Analysis (미꾸라지(Misgurnus mizolepis) Apolipoprotein A-I cDNA의 구조, 분자계통 및 발현 특징 분석)

  • Lee, Youn-Ho;Noh, Jae-Koo;Kim, Keun-Yong;Cho, Young-Sun;Nam, Yoon-Kwon;Kim, Dong-Soo
    • Journal of Aquaculture
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    • v.20 no.1
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    • pp.65-72
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    • 2007
  • Full length complementary DNA encoding apolipoprotein A-I (apoA-I) was isolated and characterized in mud loach (Misgurnus mizolepis). Mud loach apoA-I cDNA encoding 24 bp of 5'-untranslated region (UTR), 762 bp of single open reading frame (ORF) consists of 254 amino acids and 293 bp of 3'-UTR excluding stop codon and poly (A+) tail. Two overlapping polyadenylation signals (AATAAAATAAA) was found 9 bp prior to the poly (A+) tail. Mud loach apoA-I represented considerable homology to those from other teleost species at amino acid level with conserving common features of vertebrate apoA-I. Molecular phylogenetic analysis inferred the phylogenetic hypothesis that was generally in accordance with the previous taxonomic relationship. Apolipoprotein A-I mRNA was detected in various tissues, but the mRNA levels were quite varied depending on tissues based on semi-quantitative RT-PCR. Liver and brain showed the significantly higher levels of apoA-I transcripts than other tissues. mRNA expression of apoA-I was quite low in very early stage of embryonic development, however dramatically enhanced from 8 hours post fertilization. This increased mRNA level was retained consistently up to 14 days post hatching.

Quorum Sensing of Rhodobacter sphaeroides Negatively Regulates Cellular Poly-$\beta$-Hydroxybutyrate Content Under Aerobic Growth Conditions

  • Lee, Jeong-K.;Kho, Dhong-Hyo;Jang, Ji-Hee;Kim, Hye-Sun;Kim, Kun-Soo
    • Journal of Microbiology and Biotechnology
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    • v.13 no.3
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    • pp.477-481
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    • 2003
  • The community escape response of Rhodobacter sphaeroides is exerted through the action of CerR and CerI, which code for a LuxR-type regulatory protein and acylhomoserine lactone synthase, respectively. Deletion of chromosomal DNA including cerR and cerI (mutant RI) or insertional interruption of cert (mutant AP3) resulted in two-fold increase in the cellular poly-${\beta}$-hydroxybutyrate (PHB) content In comparison with the wild-type under aerobic growth conditions. The PHB synthase (PhbC) activities of the cer mutants were doubled, and the enzyme expression was regulated at the level of phbC transcription. Thus, CerR, possibly in response to autoinducer (AI), appears to modulate the PHB content of aerobically grown cells by downregulating phbC transcription.

Raman Scattering Characteristics on 3C-SiC Thin Films Deposited by APCVD Method (APCVD법으로 증착한 3C-SiC 박막의 라만 산란 특성)

  • Jeong, Jun-Ho;Chung, Gwiy-Sang
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.20 no.7
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    • pp.606-610
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    • 2007
  • This paper describes the Raman scattering characteristics of polycrystalline (poly) 3C-SiC thin films, in which they were deposited on the oxidized Si substrate by APCVD method according to growth temperature. Since the phonon modes were not measured for $0.4{\mu}m$ thick 3C-SiC, $2.0{\mu}m$ thick 3C-SiC deposited on the oxidized Si at $1180^{\circ}C$, in which TO (transverse optical mode) and LO (longitudinal optical mode) phonon modes were appeared at 794.4 and $965.7cm^{-1}$, respectively. The broad FWHM (full width half maximum) can explain that the crystallinity of 3C-SiC deposited at $1180^{\circ}C$ becomes polycrystalline instead of disorder crystal. Additionally, the ratio of intensity $I_{LO}/I_{TO}{\approx}1.0$ of 3C-SiC indicates that the crystal disorder of $3C-SiC/SiO_2/Si$ is small. Compared poly $3C-SiC/SiO_2$ with $SiO_2/Si$ interfaces, $1122.6cm^{-1}$ phonon mode was measured which may belong to C-O bonding and two phonon modes, 1355.8 and $1596.8cm^{-1}$ related to D and G bands of C-C bonding in the Raman range of 200 to $2000cm^{-1}$.

RNA Binding Specificities of Double-Stranded RNA Binding Protein (RBF) as an Inhibitor of PRK Kinase (PKR인산화효소 억제인자인 이중선RNA결합단백질 (RBF)의 RNA결합특이성)

  • 박희성;최장원
    • Journal of Life Science
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    • v.6 no.4
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    • pp.234-240
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    • 1996
  • A double-stranded RNA binding factor (RBF), characterized as an inhibitor of PKR kinase in our previous study, was evaluated for its RNA binding specificities by RNA gel electrophoretic mobility shift analysis and membrane filter binding assay, RBF displayed affinities for a broad range of RNAs including viral RNAs and synthetic RNAs consiting of stem and loop structures. GC-rich RNA stem helices as short as 11 bp are suggested to represent the minimal binding motif for RBF. RBF binding to all the natural RNAs tested was reversible by poly(I): poly(C) addition, but E. coli 5S RNA was inefficient.

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Comparative Study of Nucletic Acid Binding of the Purified RBF Protein and Its Inhibition of PKR phosphorylation (RBF정제단백질의 핵산결합도 및 PKR효소의 인산화억제효과의 비교에 관한 연구)

  • 박희성;김인수
    • Journal of Life Science
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    • v.8 no.2
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    • pp.119-125
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    • 1998
  • Column-purified double-stranded RNA binding factor (RBF) protein was tested for its binding affinity for the different forms of nucleic acids structure such as single-stranded(ss) and double-stranded(ds)RNA and ss- and dsDNA. The RBF protein was incubated with each of these nucleic acid structures in separate reactions and its comparative binding affnity was visualized by SDS-polyacrylamide gel electrophoresis. The RBF protein bound to the dsRNA molecule to form a tight RNA:protein complex in agreement with previous studies, but not to the other nucleic acid molecules confirming its distinctive affinity for the dsRNA structure. In phosphorylation assay in vito, the purified RBF protein significantly inhibited the autophosphorylation of the PKR derived from not only human but mouse source in the presence of poly(I):poly(C). It is suggesting that PKR vs. RBF is similarly under a competitive interaction among different eukaryotic organisms during protein synthesis.

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