127 results match your criteria: "Pohang University of Science Technology[Affiliation]"

ZNF224 is a Krüppel-associated box-containing zinc-finger protein which represses gene transcription by interacting with various co-repressors. However, its consensus DNA sequences and target genes are not fully identified. In this study, we identified and characterized consensus DNA sequences containing 5'-CAGC-3' recognized by ZNF224 through ChIP-sequencing, which further confirmed by ELISA, SPR, qPCR, and luciferase activity assay.

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Influence of the Solvent Quality on Ring Polymer Dimensions.

Macromolecules

March 2015

Institute of Electronic Structure and Laser, Foundation for Research and Technology-Hellas (FORTH), P.O. Box 1527, Heraklion, Crete 71110, Greece. Department of Materials Science and Technology, University of Crete, P.O. Box 2208, Heraklion, Crete 71003, Greece.

We present a systematic investigation of well-characterized, experimentally pure polystyrene (PS) rings with molar mass of 161 000 g/mol in dilute solutions. We measure the ring form factor at - and good-solvent conditions as well as in a polymeric solvent (linear PS of roughly comparable molar mass) by means of small-angle neutron scattering (SANS). Additional dynamic light scattering (DLS) measurements support the SANS data and help elucidate the role of solvent quality and solution preparation.

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High Color-Purity Green, Orange, and Red Light-Emitting Diodes Based on Chemically Functionalized Graphene Quantum Dots.

Sci Rep

April 2016

Department of Chemical and Biological Engineering, Sookmyung Women's University, 100 Cheongpa-ro 47-gil, Yongsan-gu, Seoul 04310, Republic of Korea.

Chemically derived graphene quantum dots (GQDs) to date have showed very broad emission linewidth due to many kinds of chemical bondings with different energy levels, which significantly degrades the color purity and color tunability. Here, we show that use of aniline derivatives to chemically functionalize GQDs generates new extrinsic energy levels that lead to photoluminescence of very narrow linewidths. We use transient absorption and time-resolved photoluminescence spectroscopies to study the electronic structures and related electronic transitions of our GQDs, which reveals that their underlying carrier dynamics is strongly related to the chemical properties of aniline derivatives.

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Introduction: Many hospitals are increasing their efforts to improve processes because processes play an important role in enhancing work efficiency and reducing costs. However, to date, a quantitative tool has not been available to examine the before and after effects of processes and environmental changes, other than the use of indirect indicators, such as mortality rate and readmission rate.

Methods: This study used process mining technology to analyze process changes based on changes in the hospital environment, such as the construction of a new building, and to measure the effects of environmental changes in terms of consultation wait time, time spent per task, and outpatient care processes.

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Well-defined hollow nanochanneled-silica nanospheres prepared with the aid of sacrificial copolymer nanospheres and surfactant nanocylinders.

Nanoscale

September 2015

Division of Advanced Materials Science, Department of Chemistry, Pohang Accelerator Laboratory, Polymer Research Institute, and BK School of Molecular Science, Pohang University of Science & Technology, Pohang 790-784, Korea.

A new approach for synthesizing well-defined hollow nanochanneled-silica nanosphere particles is demonstrated, and the structural details of these particles are described for the first time. Positively charged styrene copolymer nanospheres with a clean, smooth surface and a very narrow size distribution are synthesized by surfactant-free emulsion copolymerization and used as a thermal sacrificial core template for the production of core-shell nanoparticles. A surfactant/silica composite shell with a uniform thickness is successfully produced and deposited onto the polymeric core template by charge density matching between the polymer nanosphere template surface and the negatively charged silica precursors and then followed by selective thermal decomposition of the polymeric core and the surfactant cylinder domains in the shell, producing the hollow nanochanneled-silica nanospheres.

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Two-photon microscopy of a Flt1 peptide-hyaluronate conjugate.

Nanomedicine (Lond)

June 2016

Department of Materials Science & Engineering, Pohang University of Science & Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang 790-784, Korea.

Aim: Two-photon microscopy was performed to visualize ocular distribution of Flt1 peptide-hyaluronate (HA) conjugate micelles for eye drop treatment of corneal neovascularization.

Materials & Methods: Flt1 peptide-HA conjugate micelles were topically administered to the eye for two-photon microscopy and antiangiogenic effect assessment after silver nitrate cauterization.

Results: In vivo two-photon microscopy revealed that Flt1 peptide-HA conjugate micelles were absorbed and remained on the corneal epithelia with an increased residence time, facilitating the corneal delivery of carboxyfluorescein succinimidyl ester (CFSE) as a model drug.

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Gas hydrate inhibition by perturbation of liquid water structure.

Sci Rep

June 2015

Department of Chemical Engineering, Pohang University of Science &Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 790-784, Korea.

Natural gas hydrates are icy crystalline materials that contain hydrocarbons, which are the primary energy source for this civilization. The abundance of naturally occurring gas hydrates leads to a growing interest in exploitation. Despite their potential as energy resources and in industrial applications, there is insufficient understanding of hydrate kinetics, which hinders the utilization of these invaluable resources.

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A DNA hydrogel is reported as a delivery vehicle for gold nanorods and doxorubicin. The two photothermal and chemo cancer agents were co-loaded using electrostatic and DNA binding interactions, respectively. Light-triggered and highly synergistic combination cancer therapy was demonstrated in cellular and animal models.

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Light-responsible DNA hydrogel-gold nanoparticle assembly for synergistic cancer therapy.

J Mater Chem B

February 2015

School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science & Technology (POSTECH), San 31, Hyojadong, Namgu, Pohang 790-784, South Korea.

Assembled AuNPs in a DNA hydrogel (Dgel) showed strongly coupled plasmon modes, and the Dgel vehicle can co-load anticancer drugs such as doxorubicin (Dox) as a light-controlled releasing cargo by DNA intercalations. Upon laser excitation, local heat shock generation was accompanied by the release of Dox. A highly synergistic combination of thermo- and chemotherapy was demonstrated in cellular and animal models.

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Polycomb group protein-mediated histone modifications during cell differentiation.

Epigenomics

September 2015

Division of Integrative Biosciences & Biotechnology, Pohang University of Science & Technology (POSTECH), Pohang, Gyeongbuk 790-784, Republic of Korea.

Polycomb group (PcG) proteins play an important role in the regulation of gene expression, especially genes encoding lineage-specific factors. Perturbations in PcG protein expression may trigger an unexpected developmental pathway, resulting in birth defects and developmental disabilities. Two Polycomb repressive complexes, PRC1 and PRC2, have been identified and are related with diverse cellular processes through histone modifications.

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Clues to the electrical switching mechanism of carbazole-containing polyimide thin films.

ACS Appl Mater Interfaces

December 2014

Department of Chemistry, Division of Advanced Materials Science, Center for Electro-Photo Behaviors in Advanced Molecular Systems, Pohang Accelerator Laboratory, Polymer Research Institute, and BK School of Molecular Science, Pohang University of Science & Technology (POSTECH), Pohang 790-784, Repu

The mechanism behind electrical memory behavior of carbazole-containing polyimides (PIs) in nanoscale thin films was investigated. For this investigation, a series of poly(3,3'-dihydroxy-4,4'-biphenylene-co-3,3'-bis(N-ethylenyloxycarbazole)-4,4'-biphenylene hexafluoro-isopropylidenedi-phthalimide)s (6F-HAB-HABCZn PIs) with various compositions was synthesized as a model carbazole-containing polymer system. The thermal properties, band gaps, and molecular orbital levels of the PIs were determined.

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Gas hydrates are crystalline ice-like solid materials enclosing gas molecules inside. The possibility of the presence of gas hydrates with amino acids in the universe is of interest when revealing the potential existence of life as they are evidence of a source of water and organic precursors, respectively. However, little is known about how they can naturally coexist, and their crystallization behavior would become far more complex as both crystallize with formation of hydrogen bonds.

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Gold nanoparticles (AuNPs) are attractive photothermal agents for cancer therapy because they show efficient local heating upon excitation of surface plasmon oscillations. The strong absorption, efficient heat conversion, high photostability, inherent low toxicity and well-defined surface chemistry of AuNPs contribute to the growing interest in their photothermal therapy (PTT) applications. The facile tunability of gold nanostructures enables engineering of AuNPs for superior near-infrared photothermal efficacy and target selectivity, which guarantee efficient and deep tissue-penetrating PTT with mitigated concerns regarding side effects by nonspecific distributions.

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Self-assembly of novel lipid-mimicking brush polymers in nanoscale thin films.

Soft Matter

February 2014

Department of Chemistry, Division of Advanced Materials Science, Center for Electro-Photo Behaviors in Advanced Molecular Systems, Pohang Accelerator Laboratory, Polymer Research Institute, and BK School of Molecular Science, Pohang University of Science & Technology, Pohang 790-784, Republic of Kor

A series of well-defined poly(oxy(11-phosphorylcholineundecylthiomethyl)ethylene-ran-oxy(n-dodecylthiomethyl)ethylene) (PECH-PCm: m = 0-100 mol% phosphorylcholine (PC)) polymers were used to prepare nanoscale thin films that were characterized by synchrotron X-ray reflectivity (XR) analysis. The quantitative XR analysis provided structural insights into the PECH-PCm thin films. The PECH-PC0 polymer film formed a well-ordered in-plane oriented molecular multibilayer structure, whose individual layers consisted of two sublayers.

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Digital memory versatility of fully π-conjugated donor-acceptor hybrid polymers.

ACS Appl Mater Interfaces

June 2014

Department of Chemistry, Division of Advanced Materials Science, Center for Electro-Photo Behaviors in Advanced Molecular Systems, Pohang Accelerator Laboratory, Polymer Research Institute, and BK School of Molecular Science, Pohang University of Science & Technology (POSTECH), Pohang 790-784, Repu

The fully π-conjugated donor-acceptor hybrid polymers Fl-TPA, Fl-TPA-TCNE, and Fl-TPA-TCNQ, which are composed of fluorene (Fl), triphenylamine (TPA), dimethylphenylamine, alkyne, alkyne-tetracyanoethylene (TCNE) adduct, and alkyne-7,7,8,8-tetracyanoquinodimethane (TCNQ) adduct, were synthesized. These polymers are completely amorphous in the solid film state and thermally stable up to 291-409 °C. Their molecular orbital levels and band gaps vary with their compositions.

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Probing the self-assembled nanostructures of functional polymers with synchrotron grazing incidence X-ray scattering.

Macromol Rapid Commun

May 2014

Department of Chemistry, Division of Advanced Materials Science, Pohang Accelerator Laboratory, Center for Electro-Photo Behaviors in Advanced Molecular Systems, Polymer Research Institute, and BK School of Molecular Science, Pohang University of Science & Technology, Pohang, 790-784, Republic of Ko

Article Synopsis
  • Understanding the surface, morphology, and atomic structures of advanced functional polymers is crucial for exploring their properties and applications.
  • Grazing incidence X-ray scattering (GIXS) is a powerful and non-destructive method developed over the last 15 years, particularly effective when combined with advanced synchrotron radiation sources.
  • The review covers GIXS theory, data analysis techniques for various polymer structures, and discusses enhancements from new synchrotron technologies to improve structural analysis.
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Various studies that derived gesture commands from users have used the frequency ratio to select popular gestures among the users. However, the users select only one gesture from a limited number of gestures that they could imagine during an experiment, and thus, the selected gesture may not always be the best gesture. Therefore, two experiments including the same participants were conducted to identify whether the participants maintain their own gestures after observing other gestures.

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Structural Characteristics of Amphiphilic Cyclic and Linear Block Copolymer Micelles in Aqueous Solutions.

ACS Macro Lett

March 2014

Department of Chemistry, Division of Advanced Materials Science, Center for Electro-Photo Behaviors in Advanced Molecular Systems, Pohang Accelerator Laboratory, Polymer Research Institute, and BK School of Molecular Science, Pohang University of Science & Technology, Pohang 790-784, Republic of Kor

The structural characteristics of aqueous micelles composed of amphiphilic cyclic poly(-butyl acrylate--ethylene oxide) (cyclic PBA--PEO) or a linear analogue (i.e., linear poly(-butyl acrylate--ethylene oxide---butyl acrylate) (linear PBA--PEO--PBA)) were examined for the first time using synchrotron X-ray scattering techniques and quantitative data analysis.

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PD-1 is a well-established negative regulator of T cell responses by inhibiting proliferation and cytokine production of T cells via interaction with its ligands, B7-H1 (PD-L1) and B7-DC (PD-L2), expressed on non-T cells. Recently, PD-1 was found to be expressed in innate cells, including activated DCs, and plays roles in suppressing production of inflammatory cytokines. In this study, we demonstrate that PD-1 KO DCs exhibited prolonged longevity compared with WT DCs in the dLNs after transfer of DCs into hind footpads.

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We present a single-molecule imaging platform that quantitatively explores the spatiotemporal dynamics of individual insulin receptors in living cells. Modified DNA aptamers that specifically recognize insulin receptors (IRs) with a high affinity were selected through the SELEX process. Using quantum dot-labeled aptamers, we successfully imaged and analyzed the diffusive motions of individual IRs in the plasma membranes of a variety of cell lines (HIR, HEK293, HepG2).

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Poly(A) RNA and Paip2 act as allosteric regulators of poly(A)-binding protein.

Nucleic Acids Res

February 2014

School of Interdisciplinary Bioscience & Bioengineering, Pohang University of Science & Technology (POSTECH), Pohang 790-784, Korea, Department of Physics, Pohang University of Science & Technology (POSTECH), Pohang 790-784, Korea, Department of Life Sciences, Pohang University of Science & Technolo

When bound to the 3' poly(A) tail of mRNA, poly(A)-binding protein (PABP) modulates mRNA translation and stability through its association with various proteins. By visualizing individual PABP molecules in real time, we found that PABP, containing four RNA recognition motifs (RRMs), adopts a conformation on poly(A) binding in which RRM1 is in proximity to RRM4. This conformational change is due to the bending of the region between RRM2 and RRM3.

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Aim: The objectives of this study were to demonstrate nonionizing photoacoustic tomography (PAT) of bladders with near-infrared absorbing gold nanocages (GNCs) as an optical-turbid tracer and to investigate the fate of GNCs after photoacoustic imaging.

Materials & Methods: The rats' bladders were visualized using PAT after transurethral injection of 2-nM GNCs. The fate of GNCs in the bladders was investigated.

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We report a pH-responsive gold nanoparticles-in-liposome hybrid nanostructure, which effectively combines the pH-responsive assembly and surface plasmon property changes of 'smart' gold nanoparticles and enhanced systemic circulation and tumor accumulation of the PEG-grafted liposomes.

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