• Title/Summary/Keyword: encapsulating

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Application of Carbon Nanotube Encapsulating Nanowire (탄소나노튜브로 둘러싸인 나노와이어 구조의 오실레이터 응용)

  • Song, Young-Jin
    • Journal of the Semiconductor & Display Technology
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    • v.6 no.4
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    • pp.1-4
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    • 2007
  • Carbon nanotube oscillators encapsulating copper nanowire were investigated by molecular dynamics simulations. The excess forces due to the carbon-carbon van der Waals interactions are higher than the excess force due to carbon-copper interactions. And the masses of copper atoms are higher than those of carbon atoms. So, the carbon atoms are easier accelerated than the copper atoms. When the encapsulated copper nanowire deforms the encapsulating nanotube, the frequency can not be estimated by the mass-frequency dependence in classical oscillation theory.

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Preparation of Microspheres Encapsulating a Recombinant TIMP-1 Adenovirus and their Inhibition of Proliferation of Hepatocellular Carcinoma Cells

  • Xia, Dong;Yao, Hui;Liu, Qing;Xu, Liang
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.12
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    • pp.6363-6368
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    • 2012
  • Objective: The study aim was to prepare poly-DL-lactide-poly (PELA) microspheres encapsulating recombinant tissue inhibitors of metalloproteinase-1 (TIMP-1) in an adenovirus to investigate its inhibition on the proliferation of hepatocellular carcinoma cells HepG2. Methods: Microspheres were prepared by encapsulating the recombinant TIMP-1 adenovirus into biodegradable PELA. The particle size, viral load, encapsulation efficiency and in-vitro release were measured. Microspheres were used to infect HepG2 cells, then infection efficiency was examined under a fluorescent microscope and ultrastructural changes assessed by TEM. Expression of TIMP-1 mRNA in HepG2 cells was examined by semi-quantitative RT-PCR and proliferation by MTT and cell growth curve assays. Results: We successfully prepared microspheres encapsulating recombinant TIMP-1 adenovirus with a diameter of $1.965{\mu}m$, an encapsulation efficiency of 60.0%, a viral load of $10.5{\times}10^8/mg$ and approximate 60% of virus release within 120 h, the total releasing time of which was longer than 240 h. The microspheres were confirmed to be non-toxic with blank microspheres. Infected HepG2 cells could stably maintain in-vitro expression of TIMP-1, with significantly effects on biological behaviour Conclusion: PELA microspheres encapsulating a recombinant TIMP-1 adenovirus can markedly inhibit the proliferation of HepG2 cells, which provides an experimental basis for polymer/chemistry-based gene therapy of hepatocellular carcinomas.

Issues and Security on IPSec: Survey (IPSec 보안 이슈와 대응 방안)

  • Hong, Sunghyuck
    • Journal of Digital Convergence
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    • v.12 no.8
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    • pp.243-248
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    • 2014
  • IPSec provides two services that are authentication header and Encapsulating Security Payload(ESP). In this research work, security issues on the Internet and the basic concept of IPSec are described. Security issues on the Internet are presented and proposed a possible solution for DDoS attack using IPSec. Therefore, this research will be able to contribute for building secure communication against DDoS attack.

PAMAM Dendrimers Augment Inhibitory Effects of Curcumin on Cancer Cell Proliferation: Possible Inhibition of Telomerase

  • Mollazade, Mahdie;Nejati-Koshki, Kazem;Akbarzadeh, Abolfazl;Zarghami, Nosratollah;Nasiri, Marzieh;Jahanban-Esfahlan, Rana;Alibakhshi, Abbas
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.11
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    • pp.6925-6928
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    • 2013
  • Background: Despite numerous useful anticancer properties of curcumin, its utility is limited due to its hydrophobic structure. In this study, we investigated the comparative antiproliferative effect of PAMAM encapsulating curcumin with naked curcumin on the T47D breast cancer cell line. Materials and Methods: Cytotoxic effects of PAMAM dendrimers encapsulating curcumin and curcumin alone were investigated by MTT assay. After treating cells with different concentrations of both curcumin alone and curcumin encapsulated for 24h, telomerase activity was determined by TRAP assay. Results: While PAMAM dendrimers encapsulating curcumin had no cytotoxicity on cancer cells, they decreased the $IC_{50}$ for proliferation and also increased the inhibitory effect on telomerase activity. Conclusions: Considering the non-toxicity in addition to effectiveness for enhancing curcumin anticancer properties, dendrimers could be considered good therapeutic vehicles for this hydrophobic agent.

Relative Parameter Contributions for Encapsulating Silica-Gold Nanoshells by Poly(N-isopropylacrylamide-co-acrylic acid) Hydrogels

  • Park, Min-Yim;Lim, Se-Ra;Lee, Sang-Wha;Park, Sang-Eun
    • Macromolecular Research
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    • v.17 no.5
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    • pp.307-312
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    • 2009
  • Core-shell hydrogel nanocomposite was fabricated by encapsulating a silica-gold nanoshell (SGNS) with poly(N-isopropylacrylamide-co-acrylic acid) (PNIPAM-co-AAc) copolymer. The oleylamine-functionalized SONS was used as a nanotemplate for the shell-layer growth of hydrogel copolymer. APS (ammonium persulfate) was used as a polymerization initiator to produce a hydrogel-encapsulated SGNS (H-SGNS). The amounts of NIPAM (N-isopropylacrylamide) monomers were optimized to reproduce the hydrogel-encapsulated SGNS. The shell-layer thickness was increased with the increase of polymerization time and no further increase in the shell-layer thickness was clearly observed over 16 h. H-SGNS exhibited the systematic changes of particle size corresponding to the variation of pH and temperature, which was originated from hydrogen-bonding interaction between PNIPAM amide groups and water, as well as electrostatic forces attributed by the ionization of carboxylic groups in acrylic acid.

Fabrication of Microcapsules Encapsulating Fluorescent Nanoparticles and Visualization of Their Inclusion (형광 나노입자를 수용하는 마이크로캡슐의 제작 및 수용 가시화)

  • Kim, Eun-Young;Kim, Hyoung-Hoon;Go, Jeung-Sang
    • Journal of the Korean Society of Visualization
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    • v.9 no.2
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    • pp.16-20
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    • 2011
  • This paper presents a fabrication method of microcapsules encapsulating fluorescent nanoparticles sensitive to an organic liquid, which is potentially applicable to the encapsulation of protein, cell and drug. It uses the supra-molecular self-assembly of a block copolymer at the interface of the stable and controllable droplets of water suspended with fluorescent nanoparticles and the polymer solved organic. The size and uniformity of the microcapsules were examined for the various polymer concentrations by using SEM image analysis. The maximum standard deviation of the produced microcapsules of less than 3.5% was obtained from the microcapsules produced from the same conditions. The inclusion of fluorescent nanoparticles was visualized in the fluorescence microscope and by using TEM image. It is shown that this fabrication method can provide the uniform size microcapsules with a higher inclusion.

CR 2945-Conjugated Liposomes for Targeting of Human Pancreatic Cancer Cells

  • Yoon, Na-Young;Kim, Jin-Seok
    • Journal of Pharmaceutical Investigation
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    • v.34 no.6
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    • pp.459-463
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    • 2004
  • CR 2945, a $gastrin/CCK_B$ receptor antagonist, was conjugated to liposome and tested for the targeting of pancreatic cancer cells in vitro. Successful conjugation was confirmed by FTIR and NMR. The size of CR 2945-conjugated liposome was about 500 nm in diameter, with the zeta-potential being -16.5 mV. In vitro anti-cancer activity of this formulation with or without gemcitabine encapsulated was tested on human pancreatic cancer cells, PANC-1. The growth inhibitory effect of gemcitabine-encapsulating CR 2945-conjugated liposome was found to be 10-fold more potent than that of gemcitabine-encapsulating non-conjugated liposome, suggesting that CR 2945 could be used as a potential cancer targeting moiety by conjugating into liposome.

A Study on Optimization of Vacuum Glazing Encapsulating Process using Frit inside a Vacuum Chamber (진공챔버 내 프리트 이용 진공유리 봉지공정 최적화에 관한 연구)

  • Park, Sang Jun;Lee, Young Lim
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.2
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    • pp.567-572
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    • 2013
  • In houses that use heating and cooling system, most of heat loss occurs through the windows, so that low-E glass, double-layered glass, and vacuum glazing are used to minimize the heat loss. In this paper, an encapsulating process that is a final process in manufacturing the vacuum glazing has been studied, and bonding in a vacuum chamber rather than atmospheric bonding was considered. For the efficiency of the encapsulating process, frit-melting temperature and bonding time were optimized with heater temperature, and the glass preheating temperature was optimized to prevent glass breakage due to thermal stress. Thus the vacuum glass was successfully manufactured based on these results and heat transmission coefficient measured was about $5.7W/m^2K$ which indicates that the internal pressure of the vacuum glazing is $10^{-2}$ torr.

Preparation and Evaluation of Poly(methylmethacrylate-co-trimethoxysilylpropylmethacrylate) Spheres Containing Whitening and Anti-wrinkle Agents (미백 및 주름개선 성분을 함유하는 Poly(methylmethacrylate-co-trimethoxysilylpropylmethacrylate) 구의 제조와 평가)

  • Jung, Taek-Kyu;Lim, Mi-Sun;Kim, Young-Back;Yoon, Kyung-Sup
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.32 no.1 s.55
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    • pp.35-44
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    • 2006
  • Recently, encapsulation studies have been tarried out to protect active agents using shell materials such as polymers, lipids, inorganic materials and the other protective materials. We have prepared copolymers of methylmethacrylate (MMA) and trimethoxysilylpropylmethacrylate (TMPMA), and the copolymers as shell materials were used for encapsulating active agents. Poly(MMA-co-TMPMA) spheres were very efficient for encapsulating active agents such as vitamin derivatives (such as retinol, retinyl palmitate, tocopheryl acetate and ascorbyl tetraisopalmitate) and oil soluble licorice extract etc. Mean diameters of poly(MMA-co-TMPMA) core-shell spheres containing active agents varied between about 0.1 to $10{\mu}m$ according to the experimental conditions. The loading amount of encapsulating active agents was 15 to 25% (w/w) and the loading yield was above 90%. The stability of active agents in poly(MMA-co-TMPMA) core-shell spheres prepared with an UV absorbing precursor increased by 25% compared with that of active agents in spheres prepared without an UV absorbing precursor.