Jong Soo Kim

Pukyong National University, Busan, Busan, South Korea

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Publications (118)410.81 Total impact

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    ABSTRACT: Non-coding microRNAs (miRNAs) regulate the translation of target messenger RNAs (mRNAs) involved in the growth and development of a variety of cells, including primordial germ cells (PGCs) which play an essential role in germ cell development. However, the target mRNAs and the regulatory networks influenced by miRNAs in PGCs remain unclear. Here, we demonstrate a novel miRNAs control PGC development through targeting mRNAs involved in various cellular pathways. We reveal the PGC-enriched expression patterns of nine miRNAs, including miR-10b, -18a, -93, -106b, -126-3p, -127, -181a, -181b, and -301, using miRNA expression analysis along with mRNA microarray analysis in PGCs, embryonic gonads, and postnatal testes. These miRNAs are highly expressed in PGCs, as demonstrated by Northern blotting, miRNA in situ hybridization assay, and miRNA qPCR analysis. This integrative study utilizing mRNA microarray analysis and miRNA target prediction demonstrates the regulatory networks through which these miRNAs regulate their potential target genes during PGC development. The elucidated networks of miRNAs disclose a coordinated molecular mechanism by which these miRNAs regulate distinct cellular pathways in PGCs that determine germ cell development.1.
    Moleculer Cells 10/2015; DOI:10.14348/molcells.2015.0146 · 2.09 Impact Factor
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    ABSTRACT: Introduction: We evaluated the relationship between symptomatic and angiographic changes in untreated cavernous sinus dural arteriovenous fistulas (CSdAVFs), focusing on venous drainage patterns. Methods: The clinical and radiologic features of 34 cases of untreated CSdAVF were retrospectively reviewed. We classified venous drainage patterns as type I (only antegrade drainage), type II (combined antegrade drainage and venous reflux), type III (venous reflux without antegrade drainage), or type IV (stasis or occlusion of venous reflux). Symptom changes were categorized as improvement, aggravation of initial symptoms, or symptom pattern change. Results: Twenty-one patients (61 %) showed symptom changes during follow-up (median, 12; range, 3-151 months). In the symptom improvement group (n = 10), patients who underwent follow-up angiography (n = 4) exhibited spontaneous occlusion. In the symptom aggravation group (n = 4), new venous reflux developed in 2 patients (type I to type II) and spontaneous occlusion in 2 patients (type III to spontaneous occlusion). In the symptom pattern change group (n = 7), 2 patients showed new venous reflux (type I to type II), and 5 showed stasis or occlusion of an engorged ophthalmic vein (type II or III to type IV). Angiographic regression was observed in all type III and IV patients, and cortical venous reflux (CVR) developed in 1 type I patient. Conclusion: Symptom changes correlated with chronological angiographic changes. Without treatment, most CSdAVFs behaved benignly and had a low incidence of CVR. Therefore, close observation is a possible protocol for managing CSdAVFs that have tolerable symptoms, no CVR, and no antegrade drainage despite aggravation or fluctuation in symptoms.
    Neuroradiology 09/2015; DOI:10.1007/s00234-015-1597-2 · 2.49 Impact Factor
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    ABSTRACT: Recently, induced pluripotent stem cells (iPSCs) have been generated in vivo from reprogrammable mice. These in vivo iPSCs display features of totipotency, i.e., they differentiate into the trophoblast lineage, as well as all 3 germ layers. Here, we developed a new reprogrammable mouse model carrying an Oct4-GFP reporter gene to facilitate the detection of reprogrammed pluripotent stem cells. Without doxycycline administration, some of the reprogrammable mice developed aggressively growing teratomas that contained Oct4-GFP(+) cells. These teratoma-derived in vivo PSCs were morphologically indistinguishable from ESCs, expressed pluripotency markers, and could differentiate into tissues of all 3 germ layers. However, these in vivo reprogrammed PSCs were more similar to in vitro iPSCs than ESCs and did not contribute to the trophectoderm of the blastocysts after aggregation with 8-cell embryos. Therefore, the ability to differentiate into the trophoblast lineage might not be a unique characteristic of in vivo iPSCs.
    Scientific Reports 08/2015; 5:13559. DOI:10.1038/srep13559 · 5.58 Impact Factor
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    ABSTRACT: We report detailed analysis of the thin film morphology (molecular packing, molecular conformational order, and vertical phase separation) - performance (charge transport, photocurrent generation, and photovoltaic performance) relationships under nanowire formation and subsequent thermal annealing in polymer:fullerene blends. Nanowires of poly(3-hexylthiophene) (P3HT) are formed by controlled precipitation from solution and blended with [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) to form bulk heterojunction thin films. The formation of nanowires and further thermal annealing result in increased molecular order of the P3HT, where the short-range conformational order is maximised by annealing at 100 °C and decreases when annealed at higher temperatures, but the quality of long-range molecular packing and lamellar packing distance increase with annealing temperature up to 150 °C. The long-range order correlates strongly with an increase in hole mobility, but the reduction in short-range conformational order indicates a slight reduction in planarity of the conjugated backbone in this aggregated polymer morphology. Photoconductive atomic force microscopy reveals enhancemed connectivity of the hole transporting nanowire network as a result of thermal annealing. Additionally, we find that the nanowire morphology results in a favourable vertical phase separation, with PCBM enrichment at the electron-extracting surface in the conventional architecture, which is contrary to the non-nanowire case. This effect is further encouraged by thermal annealing, resulting in an enhancement of open-circuit voltage, and represents a morphological advantage over conventional P3HT:PCBM devices. Our study identifies an important interplay between long-range and short-range molecular order in charge generation, transport, extraction, and hence solar cell device performance.
    08/2015; DOI:10.1039/C5TC01720C
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    ABSTRACT: The purpose of this study was to determine the prevalence and characteristics of symptomatic coronary heart disease (CHD) in patients with moyamoya disease (MMD). This retrospective study evaluated 456 patients who received examination for MMD between 1995 and 2012. We reviewed the patients' medical history and coronary imaging, including conventional coronary angiography and coronary computed tomography angiogram (CTA). Among 456 patients with MMD, 21 (4.6%) patients were found to have symptomatic CHD. Ten patients were treated with coronary artery bypass graft or percutaneous coronary intervention for unstable angina or myocardial infarction. Eleven were treated with medication for stable angina (n = 6) and variant angina with mild degree of stenosis (n = 5).The median age of these patients was 44 yr (range, 27-59). The median Framingham score at diagnosing MMD was < 1% (range, < 1%-16%). The old age was associated with CHD in uni- and multivariate analyses (P = 0.021, OR, 1.053; 95% CI, 1.008-1.110). Considering low age of onset and low stroke risk factor, CHD might be a systemic manifestation that is clinically relevant to MMD. Graphical Abstract
    Journal of Korean medical science 04/2015; 30(4):470-4. DOI:10.3346/jkms.2015.30.4.470 · 1.27 Impact Factor
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    ABSTRACT: Reprogramming is one of the most essential areas of research in stem cell biology. Despite this importance, the mechanism and correlates of reprogramming remain largely unknown. In this study, we investigated the cytoplasmic remodeling and changes in metabolism that occur during reprogramming and differentiation of pluripotent stem cells. Specifically, we examined the cellular organelles of three pluripotent stem cells, embryonic (ESCs), induced pluripotent (iPSCs), and epiblast stem cells (EpiSCs), by electron microscopy. We found that the cellular organelles of primed pluripotent EpiSCs were more similar to those of naïve pluripotent ESCs and iPSCs than somatic cells. EpiSCs, as well as ESCs and iPSCs, contain large nuclei, poorly developed endoplasmic reticula, and underdeveloped cristae; however, their mitochondria were still mature relative to the mitochondria of ESCs and iPSCs. Next, we differentiated these pluripotent stem cells into neural stem cells (NSCs) in vitro and compared the morphology of organelles. We found that the morphology of organelles of NSCs differentiated from ESCs, iPSCs, and EpiSCs were indistinguishable from brain-derived NSCs. Finally, we examined the changes in energy metabolism that accompanied mitochondrial remodeling during reprogramming and differentiation. We found that the glycolytic activity of ESCs and iPSCs was greater than that of EpiSCs, and that the glycolytic activity of EpiSCs was greater than that of NSCs differentiated from ESCs, iPSCs, and EpiSCs. These results suggest that a change in cellular state is accompanied by dynamic changes in the morphology of cytoplasmic organelles and corresponding changes in energy metabolism.
    Stem Cells and Development 01/2015; 24(11). DOI:10.1089/scd.2014.0561 · 3.73 Impact Factor
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    ABSTRACT: Photoluminescent hybrids of poly(ε-caprolactone) (PCL), polyhedral oligosilsesquioxane (POSS) and terbium ions (Tb3+) were synthesized by using a combination of ring-opening polymerization (ROP), click chemistry and coordination chemistry. Initially, acetylene functionalized PCL (alkyne-PCL-COOH) was prepared by using ROP of ε-caprolactone with propargyl alcohol, and azide-substituted POSS (POSS-N3) was prepared by using the reaction of chloropropyl-heptaisobutyl-substituted POSS with NaN3. The click reaction between alkyne-PCL-COOH and POSS-N3 afforded POSS-g-PCL, which was subsequently coordinated with Tb3+ ions in the presence of 1,10-phenanthroline to produce POSS-g-PCL-Tb3+-Phen. The structures and compositions of the hybrids were investigated by using 1H nuclear magnetic resonance (NMR), Fourier-transform infrared spectroscopy (FT-IR), Field emission scanning electron microscope (FE-SEM), Transmission electron microscopy (TEM), and Thermogravimetric analysis (TGA). The optical properties of POSS-g-PCL-Tb3+-Phen complexes were characterized by using photoluminescence spectroscopy, which showed four high emission bands centered at 489, 545, 584, and 620 nm with excitation at 330 nm. The emission spectra of the europium-ion-coordinated hybrids, POSS-g-PCL-Eu3+-Phen, had four high-intensity peaks, 594, 617, 652 and 686 nm, for an excitation wavelength of 352 nm.
    Journal- Korean Physical Society 01/2015; 66(1):108-112. DOI:10.3938/jkps.66.108 · 0.42 Impact Factor
  • Jong Soo Kim · Hyun Woo Choi · Yean Ju Hong · Jeong Tae Do
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    ABSTRACT: Induced pluripotent stem (iPS) cells can be directly generated from somatic cells by overexpression of defined transcription factors. iPS cells can perpetually self-renew and differentiate into all cell types of an organism. iPS cells were first generated through infection with retroviruses that contain reprogramming factors. However, development of an exogene-free iPS cell generation method is crucial for future therapeutic applications, because integrated exogenes result in the formation of tumors in chimeras and regain pluripotency after differentiation in vitro. Here, we describe a method to generate iPS cells by transfection of plasmid vectors and to convert partially reprogrammed cells into fully reprogrammed iPS cells by switching from mouse ESC culture conditions to KOSR-based media with bFGF. We also describe basic methods used to characterize fully reprogrammed iPS cells.
    Methods in molecular biology (Clifton, N.J.) 12/2014; DOI:10.1007/7651_2014_161 · 1.29 Impact Factor
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    ABSTRACT: The effects of heteroatom substitution from a silicon atom to a germanium atom in donor-acceptor type low band gap copolymers, poly[(4,4′-bis(2-ethylhexyl)dithieno[3,2-b:2′,3′-d]silole)-2,6-diyl-alt-(2,1,3-benzothiadiazole)-4,7-diyl] (PSiBTBT) and poly[(4,4′-bis(2-ethylhexyl)dithieno[3,2-b:2′,3′-d]germole)-2,6-diyl-alt-(2,1,3-benzothiadiazole)-4,7-diyl] (PGeBTBT), are studied. The optoelectronic and charge transport properties of these polymers are investigated with a particular focus on their use for organic photovoltaic (OPV) devices in blends with phenyl-C70-butyric acid methyl ester (PC70BM). It is found that the longer C-Ge bond length, in comparison to C-Si, modifies the molecular conformation and leads to a more planar chain conformation in PGeBTBT than PSiBTBT. This increase in molecular planarity leads to enhanced crystallinity and an increased preference for a face-on backbone orientation, thus leading to higher charge carrier mobility in the diode configuration. These results provide important insight into the impact of the heavy atom substitution on the molecular packing and device performance of polymers based on the poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b]-dithiophene)-alt-4,7-(2,1,3-benzothiadiazole) (PCPDTBT) backbone.
    Advanced Energy Materials 12/2014; 4(18). DOI:10.1002/aenm.201400527 · 16.15 Impact Factor
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    ABSTRACT: Direct reprogramming of somatic cells to pluripotent stem cells entails the obliteration of somatic cell memory and the reestablishment of epigenetic events. Induced pluripotent stem (iPS) cells have been created by reprogramming somatic cells through the transduction of reprogramming factors. During cell reprogramming, female somatic cells must overcome at least one more barrier than male somatic cells in order to enter a pluripotent state, as they must reactivate an inactive X chromosome (Xi). In this study, we investigated whether the sex of somatic cells affects reprogramming efficiency, differentiation potential, and the post-transcriptional processing of Xist RNA after reprogramming. There were no differences between male and female iPS cells with respect to reprogramming efficiency or their differentiation potential in vivo. However, reactivating Xi took longer than reactivating pluripotency-related genes. We also found that direct reprogramming leads to gender appropriate posttranscriptional reprogramming: like male embryonic stem (ES) cells, male iPS cells expressed only the long Xist isoform, whereas female iPS cells, like female ES cells, expressed both the long and short isoforms.
    Journal of Cell Science 11/2014; 128(1). DOI:10.1242/jcs.154294 · 5.43 Impact Factor
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    ABSTRACT: Differentiated somatic cells can be reprogrammed into pluripotent stem cells by transduction of exogenous reprogramming factors. After induced pluripotent stem (iPS) cells are established, exogenous genes are silenced. In the pluripotent state, retroviral genes integrated in the host genome are kept inactive through epigenetic transcriptional regulation. In the present study, we tried to determine whether exogenous genes remain silenced or are reactivated upon loss of pluripotency or on differentiation by using an in vitro system. We induced differentiation of iPS cells into neural stem cells (NSCs) in vitro; the NSCs appeared morphologically indistinguishable from brain-derived NSCs and stained positive for the NSC markers Nestin and Sox2. These iPS cell-derived NSCs (iPS-NSCs) were also capable of differentiating into all three neural subtypes. Interestingly, iPS-NSCs spontaneously formed aggregates on long-term culture and showed reactivation of the Oct4-GFP marker, which was followed by the formation of ES cell-like colonies. The spontaneously reverted GFP-positive (iPS-NSC-GFP+) cells expressed high levels of pluripotency markers (Oct4 and Nanog) and formed germline chimeras, indicating that iPS-NSC-GFP+ cells had the same pluripotency as the original iPS cells. The reactivation of silenced exogenous genes was tightly correlated with the downregulation of DNA methyltransferases (Dnmts) during differentiation of iPS cells. This phenomenon was not observed in doxycycline-inducible iPS cells, where the reactivation of exogenous genes could be induced only by doxycycline treatment. These results indicate that pluripotency can be regained through reactivation of exogenous genes, which is associated with dynamic change of Dnmt levels during differentiation of iPS cells. Stem Cells 2014
    Stem Cells 10/2014; 32(10). DOI:10.1002/stem.1757 · 6.52 Impact Factor
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    ABSTRACT: Somatic cells are reprogrammed to induced pluripotent stem cells (iPSCs) by overexpression of a combination of defined transcription factors. We generated iPSCs from mouse embryonic fibroblasts (with Oct4-GFP reporter) by transfection of pCX-OSK-2A (Oct4, Sox2, and Klf4) and pCX-cMyc vectors. We could generate partially reprogrammed cells (XiPS-7), which maintained over 20 passages in a partially reprogrammed state; the cells were expressed Nanog but Oct4-GFP negative. When the cells were transferred to serum-free medium (with serum replacement and bFGF), the XiPS-7 cells converted to Oct4-GFP-positive iPSCs (XiPS-7c, fully reprogrammed cells) with ESC-like properties. During the conversion of XiPS-7 to XiPS-7c, we found several clusters of slowly reprogrammed genes, which were activated at later stages of reprogramming. Our results suggest that partial reprogrammed cells can be induced to full reprogramming status by serum-free medium, in which stem cell maintenance- and gamete generation-related genes were upregulated. These long-term expandable partially reprogrammed cells can be used to verify the mechanism of reprogramming.
    Stem Cells and Development 06/2014; 23(21). DOI:10.1089/scd.2014.0020 · 3.73 Impact Factor
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    Sang Heon Han · Daejun Chang · Jong Soo Kim
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    ABSTRACT: The dispersion characteristics of hydrogen leaking through a small hole from a high-pressure source were investigated experimentally to develop guidelines for determining safety distances for hydrogen stations. Tests were carried out for leaking holes with diameters of 0.5, 0.7 and 1.0 mm and for release pressures of 100, 200, 300 and 400 bar. For these realistic hydrogen leaking conditions, the Froude numbers are so large that the buoyancy effect, manifested by the hydrogen jets bending upward, can be expected to be negligible. Flow visualization was performed using an Nd-YAG laser to confirm that the buoyancy effect was negligible. By letting a thin laser sheet penetrate the center line of a hydrogen jet conveying Al2O3 particles, the particles were illuminated and the hydrogen jet was visualized. The hydrogen concentration was measured by sampling hydrogen at five points along the jet centerline, based on the large Froude number. The measured data were always lower than the isentropic prediction.
    International Journal of Hydrogen Energy 06/2014; 39(17). DOI:10.1016/j.ijhydene.2014.03.044 · 3.31 Impact Factor
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    ABSTRACT: Charge carrier mobility is a figure of merit commonly used to rate organic semiconducting materials for their suitability in applications such as solid-state lighting or photovoltaics. Although large variations are found in published mobility values on identical materials, there is little open discussion in the literature of the reproducibility of these results. We address this with an interlaboratory study of mobility measurements performed on a set of organic semiconductors using the space-charge limited current method. We found mobility measured on nominally identical devices could vary by more than one order of magnitude, with the largest sources of variation being poor electrodes and film thickness variation. Moreover, we found that mobility values extracted from identical data by different scientists would typically vary by a factor of 3. We propose a protocol for analysis and reporting that was found to reduce this analysis variation to as little as 20%. We also present general guidelines for improving the reproducibility of benchmark mobility measurements. Crown Copyright (C) 2014 Published by Elsevier B.V.
    Organic Electronics 06/2014; 15(6). DOI:10.1016/j.orgel.2014.02.008 · 3.83 Impact Factor
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    Jin Wan Park · Yun Dan Kang · Jong Soo Kim · Jae Ho Lee · Hae Won Kim
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    ABSTRACT: The umbilical cord blood (UCB) cells have been reported to secret therapeutic signals, including a series of neurotrophic factors. This suggests the cell source provides suitable therapeutic environments for nerve regeneration that ultimately finds a possible cell therapy for nerves. In this study, we test a collagen hydrogel provides human UCB cells a proper 3D microenvironment that stimulates the release of various neurotrophic factors. When compared to 2D culture, the 3D hydrogel culture significantly enhanced the expression of a series of neutrophic factors, including neurotrophin-4, nerve growth factor, brain-derived neurotrophic factor, and ciliary neurotrophic factor as verified by the gene and protein analysis. To verify the effects of neurotrophic factors secretion, we allowed an indirect interaction of the UCB-environment with human neuronal precursor cells (hNPCs). Results showed significantly enhanced neurite outgrowth and neuronal differentiation of hNPCs. Collectively, our findings demonstrate that the collagen-based 3D hydrogel provides excellent microenvironment for UBC cells to release neurotrophic factors that will be ultimately useful for the neural repair and regeneration purposes.
    Biochemical and Biophysical Research Communications 04/2014; 447(3). DOI:10.1016/j.bbrc.2014.03.145 · 2.30 Impact Factor
  • Sung Il Park · Jong Soo Kim
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    ABSTRACT: It is common practice in many industries to use a replenishment contract with a mechanism of capacity reservation. In this paper, we focus on a multi-period capacity reservation contract practiced between a buyer, who buys a single type of product and sells it to end-customers, and two or more heterogeneous suppliers, who produce and replenish the product as agreed upon contractually. In this paper, a mathematical model including several key features of a real contract is developed for a single supplier situation from the buyer’s perspective. It is then extended to a multiple supplier model for a system in which there are several heterogeneous suppliers with different capacities and prices. A rolling-horizon implementation strategy is suggested for the efficient application of the models. Extensive computational experiments demonstrate that the model and strategy can produce cost effective contractual terms for the buyer within a few seconds.
    Applied Mathematical Modelling 03/2014; 38(s 5–6):1866–1880. DOI:10.1016/j.apm.2013.10.005 · 2.25 Impact Factor
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    ABSTRACT: Pluripotent stem cells can be derived from preimplantation and postimplantation mouse embryos. Embryonic stem cells (ESCs) derived from blastocysts are in a "naive" pluripotent state and meet all of the criteria for pluripotency, including the ability to generate live pups through tetraploid complementation. Epiblast stem cells (EpiSCs) derived from postimplantation epiblasts are in a "primed" pluripotent state. ESCs and EpiSCs show different phenotypes and gene expression patterns, and EpiSCs are thought to be less pluripotent than ESCs. In this study, we addressed whether EpiSCs can be differentiated into specialized cell types in vitro. To do this, we first derived EpiSCs from E5.5-6.5 mouse embryos containing the Oct4-GFP transgene. We found that EpiSCs expressed pluripotency markers and differentiated into all three germ layers in intro and in vivo. Interestingly, EpiSCs also efficiently differentiated into a homogenous population of neural stem cells (NSCs) in vitro. The EpiSC-derived NSCs (EpiSC-NSCs) expressed NSC markers (Nestin, Sox2, and Musashi), self-renewed for more than 20 passages, and differentiated into neuronal and glial neural cell subtypes in vitro. We then transplanted the EpiSC-NSCs into the neonatal mouse brains, and found that they were able to survive and differentiate into robust neurons and glial cells in the mouse brains, demonstrating that primed pluripotent EpiSCs efficiently form functional NSCs. We compared the global gene expression patterns of NSCs differentiated from EpiSC-NSCs, ESCs, and brain tissue and found that the expression patterns of most genes, including pluripotency and NSC specificity, were similarly clustered, but that the developmental process-related genes were distantly clustered. Moreover, the global gene expression pattern of brain-derived NSCs was more similar to that of ESC-derived NSCs than that of EpiSC-derived NSCs. Taken together, these results indicate that although NSCs, regardless of their origins, display very similar in vitro and in vivo differentiation properties, their global gene expression profiles may differ, depending on the pluripotency state, i.e., naive or primed.
    Stem Cell Research 01/2014; 12(2):506-516. DOI:10.1016/j.scr.2013.12.012 · 3.69 Impact Factor
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    ABSTRACT: Understanding the vertical phase separation of donor and acceptor compounds in organic photovoltaics is requisite for the control of charge transport behavior and the achievement of efficient charge collection. Here, the vertically phase-separated morphologies of poly(3-hexylthiophene):[6,6]phenyl-C61-butyric acid methyl ester (P3HT:PCBM) blend films are examined with transmission electron microtomography, dynamic secondary ion mass spectroscopy, and X-ray photoelectron spectroscopy. The 3D morphologies of the processed films are analyzed and how the solvent additive causes vertical segregation is determined. The photocurrent–voltage characteristics of the vertically segregated blend films are strongly dependent on the 3D morphological organization of the donor and acceptor compounds in the photoactive layer. This dependence is correlated with asymmetric carrier transport at the buried interface and the air surface in the vertically segregated blend films.
    Advanced Energy Materials 01/2014; 4(2). DOI:10.1002/aenm.201300612 · 16.15 Impact Factor
  • Jin Wan Park · Yun Dan Kang · Jong Soo Kim · Jae Ho Lee · Hae Won Kim
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    ABSTRACT: The umbilical cord blood (UCB) cells have been reported to secret therapeutic signals, including a series of neurotrophic factors. This suggests the cell source provides suitable therapeutic environments for nerve regeneration that ultimately finds a possible cell therapy for nerves. In this study, we test a collagen hydrogel provides human UCB cells a proper 3D microenvironment that stimulates the release of various neurotrophic factors. When compared to 2D culture, the 3D hydrogel culture significantly enhanced the expression of a series of neutrophic factors, including neurotrophin-4, nerve growth factor, brain-derived neurotrophic factor, and ciliary neurotrophic factor as verified by the gene and protein analysis. To verify the effects of neurotrophic factors secretion, we allowed an indirect interaction of the UCB-environment with human neuronal precursor cells (hNPCs). Results showed significantly enhanced neurite outgrowth and neuronal differentiation of hNPCs. Collectively, our findings demonstrate that the collagen-based 3D hydrogel provides excellent microenvironment for UBC cells to release neurotrophic factors that will be ultimately useful for the neural repair and regeneration purposes.
    Biochemical and Biophysical Research Communications 01/2014; · 2.30 Impact Factor
  • Jong Soo Kim · Sung Il Park · Ki Young Shin
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    ABSTRACT: This paper focuses on a quantity flexibility contract through which two or more heterogeneous suppliers periodically deliver a single type of product to a buyer as promised in the contract. The buyer starts each period by informing each supplier of the order size for the period and the reservation quantity for all future periods within a planning horizon. The order size for the current period is finalized according to the amount previously reserved, although this amount can be increased or decreased by a predetermined percentage of the reservation amount. In this paper, a linear programming model including several key features of a quantity flexibility contract is developed from the buyer's perspective. A rolling-horizon implementation strategy is suggested for efficient implementation of the contract. Computational experiments demonstrate that the proposed method can be used to determine a cost effective solution for the buyer in a reasonable amount of time.
    Computers & Operations Research 01/2014; 41(1):98-108. DOI:10.1016/j.cor.2013.08.012 · 1.86 Impact Factor

Publication Stats

2k Citations
410.81 Total Impact Points


  • 2015
    • Pukyong National University
      • Division of Systems Management and Engineering
      Busan, Busan, South Korea
    • Samsung Medical Center
      • Department of Neurosurgery
      Sŏul, Seoul, South Korea
  • 2014
    • Dankook University
      • College of Dentistry
      Eidō, North Chungcheong, South Korea
  • 2012–2014
    • Konkuk University
      • Department of Animal Biotechnology
      Sŏul, Seoul, South Korea
    • Yonsei University
      • Institute for Immunology and Immunological Diseases
      Sŏul, Seoul, South Korea
  • 2011–2014
    • Imperial College London
      • Centre for Plastic Electronics
      Londinium, England, United Kingdom
    • CHA University
      Sŏul, Seoul, South Korea
    • Korea Institute of Machinery and Materials
      Sŏul, Seoul, South Korea
    • Chonbuk National University
      • Department of Chemical Engineering
      Tsiuentcheou, North Jeolla, South Korea
  • 2007–2014
    • Pohang University of Science and Technology
      • • Department of Chemical Engineering
      • • School of Environmental Science and Engineering
      Geijitsu, Gyeongsangbuk-do, South Korea
  • 2005–2014
    • Hanyang University
      • • Major in Anatomy and Cell Biology
      • • Department of Food and Nutrition
      • • Department of Biomedical Science
      • • Department of Industrial Engineering
      Sŏul, Seoul, South Korea
  • 2003–2014
    • Korea Institute of Science and Technology
      Sŏul, Seoul, South Korea
  • 2007–2013
    • Hankuk University of Foreign Studies
      Sŏul, Seoul, South Korea
  • 2003–2012
    • Kyungpook National University
      • • Department of Physics
      • • College of Agriculture and Life Sciences
      Daikyū, Daegu, South Korea
  • 2002–2012
    • Ajou University
      • • Department of Gastroenterology
      • • Department of Pediatrics
      Sŏul, Seoul, South Korea
  • 2010
    • Korea Food and Drug Administration
      Seishō-gun, Gyeongsangbuk-do, South Korea
    • Chungbuk National University
      Chinsen, Chungcheongbuk-do, South Korea
  • 2005–2010
    • Sungkyunkwan University
      • • Department of Neurosurgery
      • • Samsung Medical Center
      Sŏul, Seoul, South Korea
  • 2003–2007
    • Korea University
      • Department of Materials Science and Engineering
      Sŏul, Seoul, South Korea
  • 2006
    • Korea Electrotechnology Research Institute-KERI
      Tsau-liang-hai, Busan, South Korea
  • 2004–2006
    • University of Ulsan
      • Department of Biological Science
      Urusan, Ulsan, South Korea