• Title/Summary/Keyword: Molecular Characteristics

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Optoelectronic Properties of Semiconductor-Atomic Superlattice Diode for SOI Applications (SOI 응용을 위한 반도체-원자 초격자 다이오드의 광전자 특성)

  • 서용진
    • Journal of the Microelectronics and Packaging Society
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    • v.10 no.3
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    • pp.83-88
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    • 2003
  • The optoelectronic characteristics of semiconducto-atomic superlattice as a function of deposition temperature and annealing conditions have been studied. The nanocrystalline silicon/adsorbed oxygen superlattice formed by molecular beam epitaxy(MBE) system. As an experimental result, the superlattice with multilayer Si-O structure showed a stable photoluminescence(PL) and good insulating behavior with high breakdown voltage. This is very useful promise for Si-based optoelectronics and quantum devices as well as for the replacement of silicon-on-insulator (SOI) in ultra-high speed and lower power CMOS devices in the future, and it can be directly integrated with silicon ULSI processing.

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Preparation and Permeation Characteristics of Finely Porous Ultrafiltration Membranes by Phase Inversion Method (상전환법에 의한 미세다공성 한외여과막의 제조 및 투과특성)

  • 홍영기;배기서
    • Textile Coloration and Finishing
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    • v.15 no.2
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    • pp.68-75
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    • 2003
  • In this work, ultrafiltration(UF) membranes were prepared using polyethersulfone(PES). The polymer was dissolved in various solvent, such as N, N-dimethyl formamide(DMF), N,-dimethyl acetamide (DMAc), N,N-dimethyl sulfoxide(DMSO) and N-methyl-2- pynolidone(NMP). Each polymer solution was casted on the glass plate, and immersed into non-solvent bath. In this way finely porous UF membranes were prepared by phase inversion method. The cross sectional structure of PES membrane was asymmetric which was consist of sponge-like sublayer, finger-like toplayer, and active skin layer. From the solute rejection experiments, the molecular weight cut off of the prepared membrane in various solvent was evaluated 10,000 for DMF, 30,000 for DMAc, 50,000 for DMSO, and 10,000 for NMP respectively.

Effects of Branch Degree of CPAM for Retention and Drainage

  • Son, Dong-Jin;Kim, Bong-Yong
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2007.11a
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    • pp.21-33
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    • 2007
  • CPAM has been applied to the paper industry for the purpose of wet-end improvement for a long time. And molecular weight and charge density have been managed most important quality factors to make CPAM for this application. Recently branched CPAM was developed to improve retention and drainage characteristics and we considered branch degree of CPAM as important factor as molecular weight and charge density. In this experiment, we tried to investigate physical and chemical properties to determine branch degree and flocculation efficiency using Arbocell pulp which was recently developed micro size pulp and finally we applied retention and drainage test under the ONP stock condition.

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Electrical Characteristics of Maleate Copolymer LB Films (말레에이트계 공중합체 L8막의 전기적 특성)

  • Yoo, Seung-Yeop;Jung, Sang-Bum;Park, Jae-Chul;Kwon, Young-Soo
    • Proceedings of the KIEE Conference
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    • 1996.07c
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    • pp.1562-1564
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    • 1996
  • Langmuir-Blodgett (LB) method have been used by many rescarcher because of its facility to control the thickness of film as molecular order and orientation of molecular. We fabricated MIM device using copolymer LB films of $2C_{18}MA-VE_2$ and elecctrical conduction mechanism in ultra-thin LB film were investigated. In our experimental results, the maleate copolymer LB film have the properity of insulator like organic ultra-thin fiim. Its diclcctric constant was about 3.5 and its voltage generation about 0.1 Volt. And Schottky current was apeared as electrical conduction current and Schottky barrier was about 0.9(eV).

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Molecular Cloning and Structural Analysis of the Antibacterial Gene from the Common Cutworm, Spodoptera litura

  • Nam, Duk-Hwa;Tae, Gun-Sik
    • BMB Reports
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    • v.31 no.6
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    • pp.536-541
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    • 1998
  • The cDNA clone encoding the antibacterial peptide (SL-1) was isolated from the fat body of the common cutworm, Spodoptera litura, immunized with E. coli K12. The primary structure analysis revealed that its deduced amino acid sequence showed the characteristics of the cecropin family antibacterial peptides and that the amino acid residues highly conserved in the antibacterial peptides from moths and flies were also conserved, implying that SL-1 was a cecropin-like, and especially cecropin B-like, peptide. The predicted secondary structure of the mature SL-1 consists of three domains: (i) an amphiphilic ${\alpha}$-helical domain (Ile-4 to Gly-18); (ii) the hinge region (Gly-23 and Pro-24); and (iii) a hydrophobic domain (Ala-25 to IIe-38).

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Morphological observations and phylogenetic position of the parasitoid nanoflagellate Pseudopirsonia sp. (Cercozoa) infecting the marine diatom Coscinodiscus wailesii (Bacillariophyta)

  • Kim, Sunju;Jeon, Chang Beom;Park, Myung Gil
    • ALGAE
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    • v.32 no.3
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    • pp.181-187
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    • 2017
  • During a sampling at Nokdong harbor, southern coast of Korea in January 2017, the marine diatom Coscinodiscus wailesii cells infected by a novel parasitoid nanoflagellate were observed. While the development process of the trophosomes of the parasitoid was more similar to that of Pseudopirsonia mucosa, division pattern of the auxosomes was similar to that of Pirsonia species. Phylogenetic analyses inferred from 18S rRNA gene sequences revealed that the parasitoid infecting C. wailesii fell within the cercozoan groups and branched as a sister lineage of the clade consisting of Pseudopirsonia mucosa and the undescribed Cercomonas sp. SIC7235, with the sequence dissimilarity of 7.3% with Pseudopirsonia mucosa. All of these developmental and molecular characteristics suggest that the parasitoid nanoflagellate infecting the diatom C. wailesii is a new Pseudopirsonia species.

Bending Characteristics of Single Crystalline Copper Nanowires (단결정 구리 나노와이어의 굽힘 특성)

  • Jung, Kwang-Sub;Cho, Maeng-Hyo
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.1896-1901
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    • 2008
  • Single crystalline copper nanowires are subjected to bending tests using molecular dynamics simulations and the embedded atom method. To observe behaviors of nanowire, bending tests are performed for various rates of deflection and different boundary conditions: fixed-free and fixed-fixed. When the deflection of nanowire becomes large, twinnings and dislocations appear, and <100> crystal structure transforms to <110>. At high rates, phase transformation occurs in whole nanowire. But, at low rates, atomic structure changes to <110> phase partially. The final deformed structures are affected by the rate of deflection and boundary conditions. These effects can be important design parameters at nanoscale.

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Purification of Low Mole-cular Weight Endo-glucanase from Cellulase and Its Action on Cellulose

  • Ryu, Wang-Shick;Ryu, D.Y.
    • Proceedings of the Korean Society for Applied Microbiology Conference
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    • 1979.10a
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    • pp.243.3-244
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    • 1979
  • Low molecular weight endo-glucanase fraction of cellulase from Trichoderma reesei was purified using Sephadex G-100 and concanavalin A-Sepha-rose 4B affinity chromatography. Its biochemical characteristics including pH profile, temperature profile and kinetic behavior were studied. The optimum conditions for enzymatic reaction were pH 6.0 and $5^{\circ}C.$ The activation energy for CMC (carboxymethylcellulose) was 10,800 cal/mole. Its adsorption to amorhous and crystalline cellulose was observed. Adsorption to amorphous cellulose was more rapid and greater than that of crystalline cellulose. Reconstitution study was performed. Significance of low molecular weight endo-glucanase on cellulose hydrolysis will be further discussed.

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Review on Targeted Treatment of Patients with Advanced-Stage Renal Cell Carcinoma: A Medical Oncologist's Perspective

  • Tanriverdi, Ozgur
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.2
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    • pp.609-617
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    • 2013
  • Renal cell carcinomas make up 3% of all cancers and one in four patients is metastatic at time of diagnosis. This cancer is one of the most resistant to cytotoxic chemotherapy. Studies have shown that the efficiency of interferon-alpha and/or interleukin-2 based immune therapies is limited in patients with metastatic renal cell carcinoma but latest advances in molecular biology and genetic science have resulted in better understanding of its biology. Tumor angiogenesis, tumor proliferation and metastasis develop by the activation of signal message pathways playing a role in the development of renal cell carcinomas. Better definition of these pathways has caused an increase in preclinic and clinical studies into target directed treatment of renal cell carcinoma. Many recent studies have shown that numerous anti-angiogenic agents have marked clinical activity. In this article, the focus is on general characteristics of molecular pathways playing a major role in renal cell carcinoma, reviewing clinical information onagents used in the target directed treatment of metastatic lesions.

Contribution of lysine-containing cationic domains to thermally-induced phase transition of elastin-like proteins and their sensitivity to different stimuli

  • Jeon, Won-Bae
    • BMB Reports
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    • v.44 no.1
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    • pp.22-27
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    • 2011
  • A series of elastin-like proteins, $SKGPG[V(VKG)_3VKVPG]_n$-(ELP1-90)WP (n = 1, 2, 3, and 4), were biosynthesized based on the hydrophobic and lysine linkage domains of tropoelastin. The formation of self-assembled hydrophobic aggregates was monitored in order to determine the influence of cationic segments on phase transition properties as well as the sensitivity to changes in salt and pH. The thermal transition profiles of the proteins fused with only one or two cationic blocks (n = 1 or 2) were similar to that of the counterpart ELP1-90. In contrast, diblock proteins that contain 3 and 4 cationic blocks displayed a triphasic profile and no transition, respectively. Upon increasing the salt concentration and pH, a stimulus-induced phase transition from a soluble conformation to an insoluble aggregate was observed. The effects of cationic segments on the stimuli sensitivity of cationic bimodal ELPs were interpreted in terms of their structural and molecular characteristics.