• Title/Summary/Keyword: Dendritic

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Electrodeposition of lead from $PbCl_2$-Acetate-Succinate Solutions (염화인-아세트산-숙신산 염 용액에서 납의 전해석출)

  • Kang, Tak
    • Journal of the Korean institute of surface engineering
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    • v.19 no.2
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    • pp.44-50
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    • 1986
  • Effects of cathodic overvoltages on the electrodeposition of lead from electrolyte containing lead chloride, ammonium acetate and sodium succinate was investigated at 20$^{\circ}C$. The use of organic additives, phenol and gelatin was found effective to inhibit the growth of dendritic crystals. At the carthodic overvoltages higher than 0.2V, the lead deposit becames less compact even in the presence of organic additives. The applications of agitation and pulse current promoted compact and shiny deposits.

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Role of Retinoic Acid in the Gut Mucosal Immunity (장관면역에 있어서 레티노인산의 역할)

  • Shon, Dong-Hwa
    • Bulletin of Food Technology
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    • v.23 no.4
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    • pp.535-543
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    • 2010
  • 장관은 우리 몸에서 가장 넓은 표면적을 가지고 있으며, 외부로부터 침입하는 이물에 대항하여 면역세포의 배치가 필수적이다. 항원과 만난 적이 없는 naive lymphocyte는 임파절 등 2차 임파기관의 수지세포(dendritic cell)가 임파구에 항원을 제시할 때 레티노인산(retinoic acid)을 생산하여 제공함으로써, 소장 조직에 특이적으로 임파구가 호밍(homing)하는 능력을 부여한다. 한편, 장에 있어서는 식품항원에 대한 면역반응을 억제할 필요가 있는데, RA는 T세포의 기능분화를 억제하여 면역관용의 성립에도 관여함이 밝혀졌다.

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The Effects of Homogenization, Hot-Forging, and Annealing Condition on Microstructure and Hardness of a Modified STD61 Hot-Work Tool Steel (균질화, 열간단조, 어닐링 조건이 개량된 STD61 열간 금형강의 미세조직과 경도에 미치는 영향)

  • Park, Gyujin;Kang, Min-Woo;Jung, Jae-Gil;Lee, Young-Kook;Kim, Byung-Hoon
    • Journal of the Korean Society for Heat Treatment
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    • v.26 no.2
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    • pp.72-79
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    • 2013
  • The effects of homogenization, hot-forging, and annealing condition on microstructure and hardness of a modified STD61 hot-work tool steel were investigated. The ingot specimen had a dendritic structure consisting of bainite and martensite. Spherical VC particles of approximately 50 nm and cuboidal (V,Ti)C particles of about 100 nm were observed in the ingot specimen. After homogenization, the dendritic structure was blurred, and the difference in hardness between martensite and bainite became narrow, resulting in the more homogeneous microstructure. Needle-shaped non-equilibrium $(Fe,Cr)_3C$ particles were additionally observed in the homogenized specimen. The hot-forged specimen had bainite single phase with spherical VC, cuboidal (V,Ti)C, and needle-shaped $(Fe,Cr)_3C$ particles. After annealing at $860^{\circ}C$, the microstructures of specimens were ferrite single phase with various carbides such as VC, $(Fe,Cr)_7C_3$, and $(Fe,Cr)_{23}C_6$ because of relatively slow cooling rates. The size of carbides in annealed specimens decreased with increasing cooling rate, resulting in the increase of hardness.

Trichomonas vaginalis α-Actinin 2 Modulates Host Immune Responses by Inducing Tolerogenic Dendritic Cells via IL-10 Production from Regulatory T Cells

  • Lee, Hye-Yeon;Kim, Juri;Ryu, Jae-Sook;Park, Soon-Jung
    • Parasites, Hosts and Diseases
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    • v.55 no.4
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    • pp.375-384
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    • 2017
  • Trichomonas vaginalis is a pathogen that triggers severe immune responses in hosts. T. vaginalis ${\alpha}$-actinin 2, $Tv{\alpha}$-actinin 2, has been used to diagnose trichomoniasis. This study was undertaken to examine the role of $Tv{\alpha}$-actinin 2 as an antigenic molecule to induce immune responses from humans. Western blot analysis using anti-$Tv{\alpha}$-actinin 2 antibodies indicated its presence in the secreted proteins of T. vaginalis. ELISA was employed to measure cytokine production by vaginal epithelial cells, prostate cells, mouse dendritic cells (DCs), or T cells stimulated with T. vaginalis or $Tv{\alpha}$-actinin 2 protein. Both T. vaginalis and $rTv{\alpha}$-actinin 2 induced cytokine production from epithelial cell lines, including IL-10. Moreover, $CD4^+CD25^-$ regulatory T cells (Treg cells) incubated with $rTv{\alpha}$-actinin 2-treated DCs produced high levels of IL-10. These data indicate that $Tv{\alpha}$-actinin 2 modulates immune responses via IL-10 production by Treg cells.

Delivery of Chicken Egg Ovalbumin to Dendritic Cells by Listeriolysin O-Secreting Vegetative Bacillus subtilis

  • Roeske, Katarzyna;Stachowiak, Radoslaw;Jagielski, Tomasz;Kaminski, Michal;Bielecki, Jacek
    • Journal of Microbiology and Biotechnology
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    • v.28 no.1
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    • pp.122-135
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    • 2018
  • Listeriolysin O (LLO), one of the most immunogenic proteins of Listeria monocytogenes and its main virulence factor, mediates bacterial escape from the phagosome of the infected cell. Thus, its expression in a nonpathogenic bacterial host may enable effective delivery of heterologous antigens to the host cell cytosol and lead to their processing predominantly through the cytosolic MHC class I presentation pathway. The aim of this project was to characterize the delivery of a model antigen, chicken egg ovalbumin (OVA), to the cytosol of dendritic cells by recombinant Bacillus subtilis vegetative cells expressing LLO. Our work indicated that LLO produced by non-sporulating vegetative bacteria was able to support OVA epitope presentation by MHC I molecules on the surface of antigen presenting cells and consequently influence OVA-specific cytotoxic T cell activation. Additionally, it was proven that the genetic context of the epitope sequence is of great importance, as only the native full-sequence OVA fused to the N-terminal fragment of LLO was sufficient for effective epitope delivery and activation of $CD8^+$ lymphocytes. These results demonstrate the necessity for further verification of the fusion antigen potency of enhancing the MHC I presentation, and they prove that LLO-producing B. subtilis may represent a novel and attractive candidate for a vaccine vector.