• Title/Summary/Keyword: molecular engineering

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A New Method to Measure the Conversion of Radiation Polymerization of Electrolyte Monomer Diallyldimethylammonium Chloride in Dilute Aqueous Solution

  • Zhang, Yalong;Yi, Min;Ren, Jing;Zhai, Maolin;Ha, Hongfei
    • Macromolecular Research
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    • v.11 no.3
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    • pp.146-151
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    • 2003
  • The dependence of electrical conductivity on concentrations of diallyldimethylammonium chloride (DADMAC) monomer, linear poly(DADMAC) and their mixture monomer/poly(DADMAC) in dilute aqueous solution exhibits a linear relationship. It was possible to calculate conversion of DADMAC polymerization by measuring its electric conductivity. Although the electrical conductivity of the poly(DADMAC) solution decreased with increasing its molecular weight, in the process of UV or ionizing radiation polymerization the molecular weight of the polymers could be kept constant in the case of fixed temperature, UV-luminous intensity or dose rate. Based on the method mentioned above, the kinetics of UV induced polymerization of DADMAC in aqueous solution was studied; the overall activation energy of polymerization of DADMAC in the water phase was calculated to be 18.8 kJ mol$^{-1}$ . ${\gamma}$-Radiation-induced polymerization of DADMAC in aqueous solution as a function of absorbed dose was studied as well. The conversion of DADMAC increased quickly with dose before 30 kGy and then increased slowly. The experimental data of both UV- and ${\gamma}$-induced polymerization were verified to be reliable by inverted ultracentrifugation method.

Nanobio Colloidal Materials for Dermatological Applications (피부과학 나노바이오 콜로이드 개발 동향)

  • Kim, Ji Eun;Park, Daehwan;Lee, Jin Yong;Seo, Hyemin;Choi, Sang Koo;Kim, Jin Woong
    • Prospectives of Industrial Chemistry
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    • v.20 no.6
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    • pp.2-12
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    • 2017
  • 최근 피부산업은 미용적인 관점뿐만 아니라 피부질환치료에 대한 관심까지 폭넓게 성장하고 있어 피부의 건강을 개선하고 치료할 수 있는 새로운 신기술 개발이 다각적으로 이루어지고 있다. 특히 기술의 고도화와 체계화를 통한 피부과학기술의 진보가 화학, 화학공학, 재료공학을 기반으로 하는 전통학문분야와 조직공학, 바이오나노공학, 감성공학 등을 기반으로 하는 신학문분야가 융복합되어 이루어지고 있다. 따라서, 본 고에서는 피부산업에서 전략적인 응용이 가능한 피부 나노바이오 콜로이드의 연구개발에 대한 최근 현황을 소개하고자 한다.

A Novel Selenium- and Copper-Containing Peptide with Both Superoxide Dismutase and Glutathione Peroxidase Activities

  • Zou, Xian-Feng;Ji, Yue-Tong;Gao, Gui;Zhu, Xue-Jun;Lv, Shao-Wu;Yan, Fei;Han, Si-Ping;Chen, Xing;Gao, Chang-Cheng;Liu, Jun-Qiu;Luo, Gui-Min
    • Journal of Microbiology and Biotechnology
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    • v.20 no.1
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    • pp.88-93
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    • 2010
  • Superoxide dismutase (SOD), glutathione peroxidase (GPX), and catalase (CAT) play crucial roles in balancing the production and decomposition of reactive oxygen species (ROS) in living organisms. These enzymes act cooperatively and synergistically to scavenge ROS. In order to imitate the synergism of these enzymes, we designed and synthesized a novel 32-mer peptide (32P) on the basis of the previous 15-mer peptide with GPX activity and a 17-mer peptide with SOD activity. Upon the selenation and chelation of copper, the 32-mer peptide was converted to a new Se- and Cu-containing 32-mer peptide (Se-Cu-32P) that displayed both SOD and GPX activities, and its kinetics was studied. Moreover, the novel peptide was demonstrated to be able to better protect vero cells from the injury induced by the xanthine oxidase (XOD)/xanthine/$Fe^{2+}$ damage system than its parents. Thus, this bifunctional enzyme imitated the synergism of SOD and GPX and could be a better candidate of therapeutic medicine.