• Title/Summary/Keyword: molecular flexibility

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The Organic-Inorganic Hybrid Encapsulation Layer of Aluminium Oxide and F-Alucone for Organic Light Emitting Diodes

  • Gwon, Deok-Hyeon;Seong, Myeong-Mo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.08a
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    • pp.374-374
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    • 2012
  • Nowadays, Active Matrix Organic Light-Emitting Diodes (AM-OLEDs) are the superior display device due to their vivid full color, perfect video capability, light weight, low driving power, and potential flexibility. One of the advantages of AM-OLED over Liquid Crystal Display (LCD) lies in its flexibility. The potential flexibility of AM-OLED is not fully explored due to its sensitivity to moisture and oxygen which are readily present in atmosphere, and there are no flexible encapsulation layers available to protect these. Therefore, we come up with a new concept of Inorganic-Organic hybrid thin film as the encapsulation layer. Our Inorganic layer is Al2O3 and Organic layer is F-Alucone. We deposited these layers in vacuum state using Atomic Layer Deposition (ALD) and Molecular Layer Deposition (MLD) techniques. We found the results are comparable to commercial requirement of 10-6 g/m2 day for Water Vapor Transmission Rate (WVTR). Using ALD and MLD, we can control the exact thin film thickness and fabricate more dense films than chemical or physical vapor deposition methods. Moreover, this hybrid encapsulation layer potentially has both the flexibility of organic layers and superior protection properties of inorganic layer.

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Molecular Design for the Formation of Two-dimensional Molecular Networks: STM Study of ${\gamma}$-phenylalanine on Au(111)

  • Jeon, A-Ram;Youn, Young-Sang;Lee, Hee-Seung;Kim, Se-Hun
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.08a
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    • pp.205-205
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    • 2011
  • The self-assembly of ${\gamma}$-phenylalanine on Au(111) at 150 K was investigated using scanning tunneling microscopy (STM). Phenylalanine can potentially form two-dimensional (2D) molecular networks through hydrogen bonding (through the carboxyl and amino groups) and ${\pi}-{\pi}$ stacking interactions (via aromatic rings). We found that ${\gamma}$-phenylalanine molecules self-assembled on Au(111) surfaces into well-ordered structures such as ring-shaped clusters (at low and intermediate coverages) and 2D molecular domains (intermediate and monolayer coverages), whereas ${\alpha}$-phenylalanine molecules formed less-ordered structure on Au(111). The self-assembly of ${\gamma}$- but not ${\alpha}$-phenylalanine may be related to the flexibility of the carboxyl and amino groups in the molecule. Moreover, as expected, the 2D molecular network of ${\gamma}$-phenylalanine on Au(111) was mediated by a combination of hydrogen bonding and ${\pi}-{\pi}$ stacking interactions.

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Rational Design of Coordination Polymers with Flexible Oxyethylene Side Chains

  • Choi, Eun-Young;Gao, Chun-Ji;Lee, Suck-Hyun;Kwon, O-Pil
    • Bulletin of the Korean Chemical Society
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    • v.33 no.4
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    • pp.1264-1267
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    • 2012
  • We rationally designed and synthesized metallopolymers with organic 1,4-benzenedicarboxylic acid (BDC) linkers with different lengths of oxyethylene side chains in order to examine the influence of side chains on the coordination characteristics. While in a previous report the BDC linkers with alkyl side chains were found to form three-dimensional (3D) isoreticular metal-organic framework (IRMOF) structures or one-dimensional (1D) coordination polymeric structures with short $-O(CH_2)_6CH_3$ or long $-O(CH_2)_9CH_3$ side chains, respectively, new BDC linkers with oxyethylene side chains of the same lengths, $-(OCH_2CH_2)_2CH_3$ and $-(OCH_2CH_2)_3CH_3$, form only 3D IRMOF structures. This result is attributed to the higher flexibility and smaller volume of oxyethylene side chains compared to alkyl side chains.

Molecular Structural Characterization of Properties of Polymethacrylates by Molecular Modeling Techniques

  • Jung, Keun-Yung;Kim, Hyung-Il;Ju-Whan Liu
    • Macromolecular Research
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    • v.8 no.2
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    • pp.59-65
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    • 2000
  • We simulated the conformational changes of polymethacrylates which have side chains with different lengths (methyl and butyl) by molecular dynamics simulation technique. Bulk states of atactic amorphous polymers relaxed at a higher temperature were generated. The chain behaviors of polymethacrylates were investigated upon varying temperatures. Molecular structural information was then obtained by characterizing radial distribution function(RDF), mean square displacement, self diffusion constant, and Connolly surfaces, among others. The estimated self diffusion constants and RDF values of PMMA and PBMA were found to be in good agreement with our expectation in view of the chain flexibility.

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Molecular imaging of polarized macrophages in tumors

  • Ran Ji Yoo;Yun-Sang Lee
    • Journal of Radiopharmaceuticals and Molecular Probes
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    • v.7 no.1
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    • pp.41-49
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    • 2021
  • Diversity and flexibility are two typical hallmarks of macrophages. Two types of macrophages, M1(classically activated macrophages) and M2(alternatively activated macrophages) exist at both ends of the commonly known macrophage polarization. M1 macrophages have inflammatory properties and are primarily responsible for defending against invading bacteria in our body. On the other hand, M2 macrophages are involved in anti-inflammatory responses and tissue remodeling. Polarized migration of macrophages is of increasing interest in regulating the initiation, generation, and resting phases of inflammatory diseases. In this review, it intend to discuss the properties and functions of tumor-associated macrophages based on polarized macrophages that affect inflammatory diseases. In addition, the purpose of this study is to investigate a molecular imaging approach that targets macrophages that affect tumor growth by controlling the polarization of macrophages that affect tumor diagnosis and treatment.

The beating effect of high crystalized nonwood fibers treated with low-molecular weighted waste celulase in the papermaking processes (Cellulase생산공정중 발생되는 저분자량 분포도의 폐효소류 처리가 고결정화된 배목재 섬유소의 고해에 미치는 영향)

  • 김병현;신종순;강영립;박병권;이성구
    • Journal of the Korean Graphic Arts Communication Society
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    • v.18 no.1
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    • pp.121-139
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    • 2000
  • This study is to test the possibility of applying the low-molecular weighted waste cellulase, which is produced in the process of cellulase production, to paper making. After experimenting on high-crystallized non-wood fibers with beating catalyst. I got the result that the condition for the optimal effect is temperature 40~6$0^{\circ}C$, the time 90min to 120min, pH 5.0 to 6.0, the enzyme contents 0.3% and that the effect of beating such as slight reduction of fiver viscosity, increase of water retention value(WRV) and shortening of fiber length was increased with waste cellulase. Through this process, the density, folding endurance, tensile strength and burst strength of paper was remarkably increased, which is inferred to result from the increased flexibility of fiber by individual characteristics of non-wood fiber, which was high-crystallized by penetrated low-molecular weight cellulases in the fiber.

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Seeds as Repositories of Recombinant Proteins in Molecular Farming

  • Moloney, Maurice M.
    • Korean Journal of Plant Tissue Culture
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    • v.27 no.4
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    • pp.283-297
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    • 2000
  • Seeds are an ideal repository for recombinant proteins in molecular farming applications. However, in order to use plant seeds efficiently for the production of such proteins, it is necessary to understand a number of fundamental biological properties of seeds. This includes a full understanding of promoters which function in a seed-specific manner, the subcellular targeting of the desired polypeptide and the final form in which a protein is stored. Once a biologically active protein has been deposited in a seed, it is also critical that the protein can be extracted and purified efficiently. In this review, these issues are examined critically to provide a number of approaches which may be adopted for production of recombinant proteins in plants. Particular attention is paid to the relationship between subcellular localization and protein extraction and purification. The robustness and flexibility of seed-based production is illustrated by examples close to or already in commercial production.

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Non-canonical targets play an important role in microRNA stability control mechanisms

  • Park, June Hyun;Shin, Chanseok
    • BMB Reports
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    • v.50 no.4
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    • pp.158-159
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    • 2017
  • MicroRNAs (miRNAs) regulate gene expression by guiding the Argonaute (Ago)-containing RNA-induced silencing complex (RISC) to specific target mRNA molecules. It is well established that miRNAs are stabilized by Ago proteins, but the molecular features that trigger miRNA destabilization from Ago proteins remain largely unknown. To explore the molecular mechanisms of how targets affect the stability of miRNAs in human Ago (hAgo) proteins, we employed an in vitro system that consisted of a minimal hAgo2-RISC in HEK293T cell lysates. Surprisingly, we found that miRNAs are drastically destabilized by binding to seedless, non-canonical targets. We showed that miRNAs are destabilized at their 3' ends during this process, which is largely attributed to the conformational flexibility of the L1-PAZ domain. Based on these results, we propose that non-canonical targets may play an important regulatory role in controlling the stability of miRNAs, instead of being regulated by miRNAs.

Unprecedented Molecular Architectures by the Controlled Self-Assembly of ${\beta}$-Peptide Foldamer

  • Kwon, Sun-Bum;Lee, Hee-Seung
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.08a
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    • pp.204-204
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    • 2011
  • During past decades, several types of peptide-based scaffolds, ranging from simple aromatic dipeptide to small protein fragments, have been studied to understand the underlying mechanism and mimic to create artificial nano/microstructures. However, a limited number of design principles have still been reported in peptidic scaffolds allowing well-defined self-assembled structure formation, presumably due to the intrinsic large conformational flexibility of natural peptides. In this presentation, we report the first example of highly homogeneous, well-defined and finite architectures by the ${\beta}$-peptide self-assembly.

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A Study on the Mechanical Properties of Knit Fabric Using 3D Printing -Focused on PLA, TPU Filament- (3D프린팅을 이용한 편성물의 역학적 특성 연구 -PLA, TPU 필라멘트를 중심으로-)

  • Han, Yoojung;Kim, Jongjun
    • Journal of Fashion Business
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    • v.22 no.4
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    • pp.93-105
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    • 2018
  • Using FDM 3D printing, yarn shape and composition were modeled and 3D printed with PLA and TPU filaments currently used for apparel. Based on this, mechanical characteristics were measured to determine 3D printing yarn according to type of filaments in the 3D printed output and deformation and recovery characteristics due to differences in structure type. As a result of examining tensile and shear characteristics of PLA and TPU 3D printing compiles, TPU overall was measured with significantly lower stress than PLA. This is due to high elasticity of TPU's character, revealing that it has better flexibility than PLA. In addition, during deformation due to external forces, the more freedom between the head and foot parts of the loop, and the lower the force associated with each other, the more flexible it is. TPU revealed that it was easier to tension and recovery from tensile deformation than PLA, indicating potential for clothing materials using 3D printing. If high-molecular materials, such as PLA flexibility, it is likely to provide some flexibility through development of styles, including degree of freedom in modeling. Based on this, we provide basic data for developing 3D printing textures that can be satisfied with textile for apparel.