• Title/Summary/Keyword: Poly(I:C)

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A Study on Curing of Poly(phenylene sulfide sulfone) (Poly(phenylene sulfide sulfone)의 경화에 관한 연구)

  • Seo, Kwan-Ho;Park, Lee-Soon;Oh, Dae-Hee
    • Applied Chemistry for Engineering
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    • v.4 no.3
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    • pp.544-548
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    • 1993
  • Glass transition temperatures($T_g$) of poly(phenylene sulfide sulfone)[PPSS], which were heat treated at various temperature and time, were studied by DSC. Up to $230^{\circ}C$, $T_g$ of heat treated PPSS were increased with increasing the heat treated time. When the sample was heated at $260^{\circ}C$ for 30 minute and $280^{\circ}C$ for 10 minute, however, $T_g$ of those samples were decreased. These phenomena can be explained by the factors of chain extension reaction, oxidative crosslinking, and thermal crosslinking.

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Color Fastness of PLA Fiber Dyed with Vat Dyes (Poly Lactic Acid 섬유의 Vat 염료에 대한 염색견뢰도)

  • Jeong, Dong-Seok;Chun, Tae-Il
    • Textile Coloration and Finishing
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    • v.25 no.1
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    • pp.75-81
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    • 2013
  • Colorimetric and wash fastness data after repeated wash cycles of Poly Lactic Acid(PLA) fiber were examined with C. I. Vat Blue 1, also other comparing 2 dyes (C. I. Vat Blue 35, C. I. Vat Blue 5), in this study. The fastness of three vat dyes on PLA fiber to repeated washing according to KS K 0430 A-2 regulation increased with dyeing temperatures. The $L^*$ values of the dyed material gradually increased with increasing numbers of wash. Also the f(k) values were decreased reversely. During repeated washing, the vagrant dyes were deposited especially on nylon, polyester, cotton of the adjacent multifiber. C. I. Vat Blue 5 displayed lowest color change to repeated washing of the three dyes used.

Deposition of Poly-$Si_{1-x}Ge_x$ Thin Film by RTCVD (RTCVD에 의한 다결정 $Si_{1-x}Ge_x$ 박막 증착)

  • Kim, Jae-Jung;Lee, Seung-Ho;So, Myeong-Gi
    • Korean Journal of Materials Research
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    • v.5 no.6
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    • pp.690-698
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    • 1995
  • The Poly-S $i_{1-x}$G $e_{x}$ thin films were deposited on oxidized Si wafer by RTCVD(rapid thermal chemical vapor deposition) using Si $H_4$and Ge $H_4$, at 450 ~5$50^{\circ}C$. The variation of Ge mole fraction and the deposition rate of S $i_{1-x}$G $e_{x}$ thin film were studied as a function of the deposition temperature and the Ge $H_4$/Si $H_4$input ratio, and the crystal phase and the surface roughness were studied by XRD and AFM(atomic force microscopy), respectively. The experimental results showed that the activation energy for the deposition of poly-S $i_{1-x}$G $e_{x}$ was about 32~37Kca /mol and the deposition rate of S $i_{1-x}$G $e_{x}$ thin films was increased with increasing the deposition temperature and the input ratio. From the analysis of composition, it was known that the Ge mole fraction within the poly-S $i_{1-x}$G $e_{x}$ thin film was decreased with decreasing the input ratio and increasing the deposition temperature. As-deposited S $i_{1-x}$G $e_{x}$ thin films were polycrystalline over the entire experimental range. But those were amorphous at the deposition temperature of 450, 475$^{\circ}C$ and the input ratio of 0.05. By adding the Ge $H_4$, poly-S $i_{1-x}$G $e_{x}$ thin film were deposited at relatively lower deposition temperatures($\leq$ 5$50^{\circ}C$) than those of conventional poly-Si(>$600^{\circ}C$). From surface roughness measurement of poly-S $i_{1-x}$G $e_{x}$ it was found that the surface roughness( $R_{i}$ ) increased with increasing the deposition temperature and input ratio.and input ratio.

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Pan-Caspase Inhibitor zVAD Induces Necroptotic and Autophagic Cell Death in TLR3/4-Stimulated Macrophages

  • Chen, Yuan-Shen;Chuang, Wei-Chu;Kung, Hsiu-Ni;Cheng, Ching-Yuan;Huang, Duen-Yi;Sekar, Ponarulselvam;Lin, Wan-Wan
    • Molecules and Cells
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    • v.45 no.4
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    • pp.257-272
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    • 2022
  • In addition to inducing apoptosis, caspase inhibition contributes to necroptosis and/or autophagy depending on the cell type and cellular context. In macrophages, necroptosis can be induced by co-treatment with Toll-like receptor (TLR) ligands (lipopolysaccharide [LPS] for TLR4 and polyinosinic-polycytidylic acid [poly I:C] for TLR3) and a cell-permeable pan-caspase inhibitor zVAD. Here, we elucidated the signaling pathways and molecular mechanisms of cell death. We showed that LPS/zVAD- and poly I:C/zVAD-induced cell death in bone marrow-derived macrophages (BMDMs) was inhibited by receptor-interacting protein kinase 1 (RIP1) inhibitor necrostatin-1 and autophagy inhibitor 3-methyladenine. Electron microscopic images displayed autophagosome/autolysosomes, and immunoblotting data revealed increased LC3II expression. Although zVAD did not affect LPS- or poly I:C-induced activation of IKK, JNK, and p38, it enhanced IRF3 and STAT1 activation as well as type I interferon (IFN) expression. In addition, zVAD inhibited ERK and Akt phosphorylation induced by LPS and poly I:C. Of note, zVAD-induced enhancement of the IRF3/IFN/STAT1 axis was abolished by necrostatin-1, while zVAD-induced inhibition of ERK and Akt was not. Our data further support the involvement of autocrine IFNs action in reactive oxygen species (ROS)-dependent necroptosis, LPS/zVAD-elicited ROS production was inhibited by necrostatin-1, neutralizing antibody of IFN receptor (IFNR) and JAK inhibitor AZD1480. Accordingly, both cell death and ROS production induced by TLR ligands plus zVAD were abrogated in STAT1 knockout macrophages. We conclude that enhanced TRIF-RIP1-dependent autocrine action of IFNβ, rather than inhibition of ERK or Akt, is involved in TLRs/zVAD-induced autophagic and necroptotic cell death via the JAK/STAT1/ROS pathway.

Effects of Molecular Weights on the Physico-pharmaceutical Properties of Poly-L-glutamic acid-cytarabine Conjugates

  • Kim, Chong-Kook;Kwon, Kyoung-Ae;Jeong, Eun-Ju;Lee, Myung-Gull
    • Archives of Pharmacal Research
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    • v.12 no.2
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    • pp.88-93
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    • 1989
  • In order to obtain some informations about the effect of molecular weight on the release rate of drug from drug carrier, two types of poly-L-glutamic acid (PLGA)-cytarabine (ara-C) conjugates, PLGA-ara-C:I and PLGA-ara-C:II, were synthesized using two types of PLGA having different average molecular weight, 43,000 and 77,800, respectively. The PLGA-ara-C conjugates were synthesized by mixed anhydride method and found to be covalently linked. Both types of conjugates charged negatively at biological pH. The pH-dependent release rate of ara-C was observed in both cases, and the release rate was accelerated in basic, acidic conditions (the k values were 0.015 $day^{-1}$ at pH 7.0, 0.024 $day^{-1}$ at pH 5.0, and 0.059 $day^{-1}$ at pH 9.0 in the case of PLGA-ara-C:I) and in the presence of pretense. The time required for the release of 16.5% of ara-C from PLGA-ara-C:I were 8 hr and 144 hr in the presence and absence of protease, respectively. Although both types of conjugates showed similar drug substitution ratio, they showed different release rates. Between the two types of conjugates, PLGA-ara-C:II showed the faster release rate (0.030 vs 0.042 $day^{-1}$ in pH 7.4 phosphate buffer solution at $37^{\circ}C$) and the smaller activation energy for the release of drug (12.5 vs 7.7 Kcal/mol) than PLGA-ara-C:I. The characteristic effect of molecular weight on the release rates of PLGA-ara-C conjugates suggests that the drug release rate might be effectively controlled over a prolonged period of time by the combined use of the different types of PLGA-ara-C conjugates having different molecular weights.

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Properties of Thin Film a-Si:H and Poly-Si TFT's

  • Ahn, Byeong-Jae;Kim, Do-Young;Yoo, Jin-Su;Yi, Jun-Sin
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.04a
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    • pp.169-172
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    • 2000
  • A-Si:H and poly-Si TFT characteristics were investigated using an inverted staggered type TFT. The poly-Si films were achieved by various anneal techniques ; isothermal, RTA, and excimer laser anneal. The TFT on as-grown a-Si:H exhibited a low field effect mobility, transconductance, and high gate threshold voltage. Some films were annealed at temperatures from $200^{\circ}C$ to $1000^{\circ}C$. The TFT on poly-Si showed an improved $I_{on}/I_{off}$ ratio of $10^6$, reduced gate threshold voltage, and increased field effect mobility by three orders. Inverter operation was examined to verify logic circuit application using the poly-Si TFTs.

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The Effects of Phenethyl Isothiocyanate on Nuclear Factor-κB Activation and Cyclooxygenase-2 and Inducible Nitric Oxide Synthase Expression Induced by Toll-like Receptor Agonists (Phenethyl Isothiocyanate가 Toll-like Receptor Agonists에 의해 유도된 Nuclear Factor-κB 활성과 Cyclooxygenase-2, Inducible Nitric Oxide Synthase 발현에 미치는 효과)

  • Kim, Soo-Jung;Park, Hye-Jeong;Shin, Hwa-Jeong;Kim, Ji-Soo;Ahn, Hee-Jin;Min, In-Soon;Youn, Hyung-Sun
    • Journal of Applied Biological Chemistry
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    • v.54 no.4
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    • pp.279-283
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    • 2011
  • Toll-like receptors (TLRs) play an important role in induction of innate immune responses. The activation of TLRs triggers inflammatory responses that are essential for host defense against invading pathogens. Phenethyl isothiocyanate (PEITC) extracted from cruciferous vegetables has an effect on anti-inflammatory therapy. Dysregulated activation of nuclear factor-${\kappa}$B (NF-${\kappa}$B), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) has been shown to play important roles in the development of certain inflammatory disease. To evaluate the therapeutic potential of PEITC, NF-${\kappa}$B activation and COX-2 and iNOS expression induced by lipopolysaccharide (LPS, TLR4 agonist), polyinosinic-polycytidylic acid (Poly[I:C], TLR3 agonist), 2 kDa macrophageactivating lipopeptide (MALP-2, TLR2 and TLR6 agonist) or oligodeoxynucleotide 1668 (ODN1668, TLR9 agonist) were examined. PEITC inhibits the activation of NF-${\kappa}$B induced by LPS or Poly[I:C] but not by MALP-2 or ODN1668. PEITC also suppressed the iNOS expression induced by LPS or Poly[I:C]. However, PEITC did not suppress COX-2 expression induced by LPS, Poly[I:C], MALP-2, or ODN1668. These results suggest that PEITC has the specific mechanism for antiinflammatory responses.

Effect of Underlying Poly-Silicon on the Thermal Staability of the Ti-silicide Film (티타니움 실리사이드 박막의 열안정성에 미치는 기판 실리콘막의 영향)

  • Kim, Yeong-Uk;Lee, Nae-In;Go, Jong-U;Kim, Il-Gwon;An, Seong-Tae;Lee, Jong-Sik;Song, Se-An
    • Korean Journal of Materials Research
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    • v.3 no.2
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    • pp.158-165
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    • 1993
  • Abstract To investigate the effect of underlying Si on the thermal stability of the TiS$i_2$ film, TiS$i_2$ films obtained by the solid-state reaction of the Ti film on as-deposited or on heat-treated poly-silicon and amorphous-silicon were annealed at 90$0^{\circ}C$ for various times. The poly-Si film was evaluated by XRD, SEM and TEM. The thermal stability of the TiS$i_2$ film was evaluated by measuring the sheet resistance and microstructural evolution during furnace annealing. Agglomeration of the TiSi, film occurred more on amorphous-Si than on poly-Si. The thermal stability of the TiS$i_2$ film was improved by annealing poly-Si. The Si layer crystallized from amorphous-Si has an equiaxed structure with the (111) preferred orientation whereas for as-deposited poly-Si has a columnar structure with the (110) orientation. Better thermal stability of the TiS$i_2$ film can be obtained by the higher surface energy of underlying poly-Si.

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Characteristic of Transistor Using Ti-SALICIDE Process and Its Application to Oscillator I,C(I) (티타늄 살리사이드 공정을 이용한 트랜지스터의 특성 및 오실레이터 I.C에의 적용(I))

  • 이상흥;구경완;홍봉식
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.28A no.11
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    • pp.910-914
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    • 1991
  • This paper describes the improvement of frequency characteristic of crystal oscillator I.C using Ti-Salicide. The characteristics of transistor(drive current) using Ti-Salicide process are better than Poly-Si process, because the mobility. To know frequency characteristic of oscillator I.C, the simulation is performed using inverter buffer chain of Fan-out 10 TTL. Its result shows at once the generation of normal clock pulse in input signal and the improvement of rising and falling time.

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Effect of Surface Treatments of Polycrystalline 3C-SiC Thin Films on Ohmic Contact for Extreme Environment MEMS Applications (극한 환경 MEMS용 옴익 접촉을 위한 다결정 3C-SiC 박막의 표면 처리 효과)

  • Chung, Gwiy-Sang;Ohn, Chang-Min
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.20 no.3
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    • pp.234-239
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    • 2007
  • This paper describes the TiW ohmic contact characteristics under the surface treatment of the polycrystalline 3C-SiC thin film grown on $SiO_2/Si(100)$ wafers by APCVD. The poly 3C-SiC surface was polished by using CMP(chemical mechanical polishing) process and then oxidized by wet-oxidation process, and finally removed SiC oxide layers. A TiW thin film as a metalization process was deposited on the surface treated poly 3C-SiC layer and was annealed through a RTA(rapid thermal annealing) process. TiW/poly 3C-SiC was investigated to get mechanical, physical, and electrical characteristics using SEM, XRD, XPS, AFM, optical microscope, I-V characteristic, and four-point probe, respectively. Contact resistivity of the surface treated 3C-SiC was measured as the lowest $1.2{\times}10^{-5}{\Omega}cm^2$ at $900^{\circ}C$ for 45 sec. Therefore, the surface treatments of poly 3C-SiC are necessary to get better contact resistance for extreme environment MEMS applications.