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Kim YH, Kim SG, Lee S, Cheon M, Kim SJ, Nam K, Lamichhane B, Park SH, Jung MH, Kim JS, Seo YS, Ha T, Hwang J, Jeong HY, Lee Y, Lee YH, Kim YM, Jeong SY. Self-Oxidation Resistance of the Curved Surface of Achromatic Copper. Adv Mater 2023; 35:e2210564. [PMID: 37548080 DOI: 10.1002/adma.202210564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 07/29/2023] [Indexed: 08/08/2023]
Abstract
Copper surfaces that exhibit a wide range of achromatic colors while still metallic have not been studied, despite advancements in antireflection coatings. A series of achromatic copper films grown with [111] preferred orientation by depositing 3D porous nanostructures is introduced via coherent/incoherent atomic sputtering epitaxy. The porous copper nanostructures self-regulate the giant oxidation resistance by constructing a curved surface that generates a series of monoatomic steps, followed by shrinkage of the lattice spacing of one or two surface layers. First-principles calculations confirm that these structural components cooperatively increase the energy barrier against oxygen penetration. The achromaticity of the single-crystalline porous copper films is systematically tuned by geometrical parameters such as pore size distribution and 3D linkage. The optimized achromatic copper films with high oxidation resistance show an unusual switching effect between superhydrophilicity and superhydrophobicity. The tailored 3D porous nanostructures can be a candidate material for numerous applications, such as antireflection coatings, microfluidic devices, droplet tweezers, and reversible wettability switches.
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Affiliation(s)
- Young-Hoon Kim
- Department of Energy Science, Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea
| | - Seong-Gon Kim
- Department of Physics and Astronomy, Mississippi State University, Starkville, MS, 39762, USA
| | - Seunghun Lee
- Department of Physics, Pukyong National University, Busan, 48513, Republic of Korea
| | - Miyeon Cheon
- Crystal Bank Research Institute, Pusan National University, Busan, 46241, Republic of Korea
| | - Su Jae Kim
- Crystal Bank Research Institute, Pusan National University, Busan, 46241, Republic of Korea
| | - Kideuk Nam
- Department of Physics, Pukyong National University, Busan, 48513, Republic of Korea
| | - Bipin Lamichhane
- Department of Physics and Astronomy, Mississippi State University, Starkville, MS, 39762, USA
| | - Sung Heum Park
- Department of Physics, Pukyong National University, Busan, 48513, Republic of Korea
| | - Min-Hyoung Jung
- Department of Energy Science, Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea
| | - Ji-Soo Kim
- Gumi Electronics and Information Technology Research Institute (GERI), Gumi, 39171, Republic of Korea
| | - Yu-Seong Seo
- Department of Physics, Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea
| | - Taewoo Ha
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science, Suwon, 16419, Republic of Korea
| | - Jungseek Hwang
- Department of Physics, Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea
| | - Hu Young Jeong
- Graduate School of Semiconductor Materials and Devices Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Yusil Lee
- Crystal Bank Research Institute, Pusan National University, Busan, 46241, Republic of Korea
| | - Young Hee Lee
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science, Suwon, 16419, Republic of Korea
| | - Young-Min Kim
- Department of Energy Science, Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science, Suwon, 16419, Republic of Korea
| | - Se-Young Jeong
- Department of Optics and Mechatronics Engineering, Department of Cogno-Mechatronics Engineering, Pusan National University, Busan, 46241, Republic of Korea
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2
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Kim YH, Kim SG, Lee S, Cheon M, Kim SJ, Jeong SY, Kim YM. Self-regulating Oxidation Resistance at Rough Surface of Achromatic Copper. Microsc Microanal 2023; 29:140-141. [PMID: 37613572 DOI: 10.1093/micmic/ozad067.063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Affiliation(s)
- Young-Hoon Kim
- Department of Energy Science, Sungkyunkwan University, Suwon, Gyeonggi-do, Republic of Korea
| | - Seong-Gon Kim
- Department of Physics and Astronomy, Mississippi State University, Mississippi, MS, United States
| | - Seunghun Lee
- Department of Physics, Pukyong National University, Busan, Republic of Korea
| | - Miyeon Cheon
- Crystal Bank Research Institute, Pusan National University, Busan, Republic of Korea
| | - Su Jae Kim
- Crystal Bank Research Institute, Pusan National University, Busan, Republic of Korea
| | - Se-Young Jeong
- Department of Cogno-Mechatronics Engineering, Pusan National University, Busan, Republic of Korea
| | - Young-Min Kim
- Department of Energy Science, Sungkyunkwan University, Suwon, Gyeonggi-do, Republic of Korea
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3
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Kim SJ, Kim SJ, Kim YH, Jung MH, Jeong HY, Jeong SY, Kim YM. Strain-Free Growth of Single-Crystal Ag Thin Films via Monolayer-Thick Interface Formation. Microsc Microanal 2023; 29:1655-1656. [PMID: 37613869 DOI: 10.1093/micmic/ozad067.852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Affiliation(s)
- Seon Je Kim
- Department of Energy Science, Sungkyunkwan University, Suwon, Republic of Korea
| | - Su Jae Kim
- Crystal Bank Research Institute, Pusan National University, Busan, Republic of Korea
| | - Young-Hoon Kim
- Department of Energy Science, Sungkyunkwan University, Suwon, Republic of Korea
| | - Min-Hyoung Jung
- Department of Energy Science, Sungkyunkwan University, Suwon, Republic of Korea
| | - Hu Young Jeong
- Graduate School of Semiconductor Materials and Devices Engineering, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | - Se-Young Jeong
- Department of Optics and Mechatronics Engineering, Pusan National University, Busan, Republic of Korea
| | - Young-Min Kim
- Department of Energy Science, Sungkyunkwan University, Suwon, Republic of Korea
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4
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Ha T, Seo YS, Kim TT, Lamichhane B, Kim YH, Kim SJ, Lee Y, Kim JC, Park SE, Sim KI, Kim JH, Kim YI, Kim SJ, Jeong HY, Lee YH, Kim SG, Kim YM, Hwang J, Jeong SY. Coherent consolidation of trillions of nucleations for mono-atom step-level flat surfaces. Nat Commun 2023; 14:685. [PMID: 36755020 PMCID: PMC9908865 DOI: 10.1038/s41467-023-36301-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 01/25/2023] [Indexed: 02/10/2023] Open
Abstract
Constructing a mono-atom step-level ultra-flat material surface is challenging, especially for thin films, because it is prohibitively difficult for trillions of clusters to coherently merge. Even though a rough metal surface, as well as the scattering of carriers at grain boundaries, limits electron transport and obscures their intrinsic properties, the importance of the flat surface has not been emphasised sufficiently. In this study, we describe in detail the initial growth of copper thin films required for mono-atom step-level flat surfaces (MSFSs). Deposition using atomic sputtering epitaxy leads to the coherent merging of trillions of islands into a coplanar layer, eventually forming an MSFS, for which the key factor is suggested to be the individual deposition of single atoms. Theoretical calculations support that single sputtered atoms ensure the formation of highly aligned nanodroplets and help them to merge into a coplanar layer. The realisation of the ultra-flat surfaces is expected to greatly assist efforts to improve quantum behaviour by increasing the coherency of electrons.
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Affiliation(s)
- Taewoo Ha
- grid.264381.a0000 0001 2181 989XCenter for Integrated Nanostructure Physics, Institute for Basic Science, Sungkyunkwan University, Suwon, 16419 Republic of Korea
| | - Yu-Seong Seo
- grid.264381.a0000 0001 2181 989XDepartment of Physics, Sungkyunkwan University, Suwon, 16419 Republic of Korea
| | - Teun-Teun Kim
- grid.267370.70000 0004 0533 4667Department of Physics, University of Ulsan, Ulsan, 44610 Republic of Korea
| | - Bipin Lamichhane
- grid.260120.70000 0001 0816 8287Department of Physics and Astronomy, Mississippi State University, Mississippi State, MS 39762 USA
| | - Young-Hoon Kim
- grid.264381.a0000 0001 2181 989XDepartment of Energy Science, Sungkyunkwan University, Suwon, 16419 Republic of Korea
| | - Su Jae Kim
- grid.262229.f0000 0001 0719 8572Crystal Bank Research Institute, Pusan National University, Busan, 46241 Republic of Korea
| | - Yousil Lee
- grid.262229.f0000 0001 0719 8572Crystal Bank Research Institute, Pusan National University, Busan, 46241 Republic of Korea
| | - Jong Chan Kim
- School of Materials Science and Engineering, Ulsan National Institute of Science and Engineering, Ulsan, 44919 Republic of Korea
| | - Sang Eon Park
- grid.262229.f0000 0001 0719 8572Crystal Bank Research Institute, Pusan National University, Busan, 46241 Republic of Korea
| | - Kyung Ik Sim
- grid.264381.a0000 0001 2181 989XCenter for Integrated Nanostructure Physics, Institute for Basic Science, Sungkyunkwan University, Suwon, 16419 Republic of Korea ,grid.15444.300000 0004 0470 5454Department of Physics, Yonsei University, Seoul, 03722 Republic of Korea
| | - Jae Hoon Kim
- grid.15444.300000 0004 0470 5454Department of Physics, Yonsei University, Seoul, 03722 Republic of Korea
| | - Yong In Kim
- grid.264381.a0000 0001 2181 989XDepartment of Energy Science, Sungkyunkwan University, Suwon, 16419 Republic of Korea
| | - Seon Je Kim
- grid.264381.a0000 0001 2181 989XDepartment of Energy Science, Sungkyunkwan University, Suwon, 16419 Republic of Korea
| | - Hu Young Jeong
- School of Materials Science and Engineering, Ulsan National Institute of Science and Engineering, Ulsan, 44919 Republic of Korea ,grid.42687.3f0000 0004 0381 814XUNIST Central Research Facilities, Ulsan National Institute of Science and Technology, Ulsan, 44919 Republic of Korea
| | - Young Hee Lee
- grid.264381.a0000 0001 2181 989XCenter for Integrated Nanostructure Physics, Institute for Basic Science, Sungkyunkwan University, Suwon, 16419 Republic of Korea ,grid.264381.a0000 0001 2181 989XDepartment of Energy Science, Sungkyunkwan University, Suwon, 16419 Republic of Korea
| | - Seong-Gon Kim
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, MS, 39762, USA.
| | - Young-Min Kim
- Center for Integrated Nanostructure Physics, Institute for Basic Science, Sungkyunkwan University, Suwon, 16419, Republic of Korea. .,Department of Energy Science, Sungkyunkwan University, Suwon, 16419, Republic of Korea.
| | - Jungseek Hwang
- Department of Physics, Sungkyunkwan University, Suwon, 16419, Republic of Korea.
| | - Se-Young Jeong
- Department of Cogno-Mechatronics Engineering, Pusan National University, Busan, 46241, Republic of Korea. .,Department of Optics and Mechatronics Engineering, Pusan National University, Busan, 46241, Republic of Korea.
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Yang D, Yadav D, Jeon I, Seo J, Jeong SY, Cho CR. Enhanced High-Rate Capability and Long Cycle Stability of FeS@NCG Nanofibers for Sodium-Ion Battery Anodes. ACS Appl Mater Interfaces 2022; 14:44303-44316. [PMID: 36165326 DOI: 10.1021/acsami.2c11046] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The development of advanced hierarchical anode materials has recently become essential to achieving high-performance sodium-ion batteries. Herein, we developed a facile and cost-effective scheme for synthesizing graphene-wrapped, nitrogen-rich carbon-coated iron sulfide nanofibers (FeS@NCG) as an anode for SIBs. The designed FeS@NCG can provide a significant reversible capacity of 748.5 mAh g-1 at 0.3 A g-1 for 50 cycles and approximately 3.9-fold higher electrochemical performance than its oxide analog (Fe2O3@NCG, 192.7 mAh g-1 at 0.3 A g-1 for 50 cycles). The sulfur- and nitrogen-rich multilayer package structure facilitates efficient suppression of the porous FeS volume expansion during the sodiation process, enabling a long cycle life. The intimate contact between graphene and porous carbon-coated FeS nanofibers offers strong structural barriers associated with charge-transfer pathways during sodium insertion/extraction. It also reduces the dissolution of polysulfides, enabling efficient sodium storage with superior stable kinetics. Furthermore, outstanding capacity retention of 535 mAh g-1 at 5 A g-1 is achieved over 1010 cycles. The FeS@NCG also exhibited a specific capacity of 640 mAh g-1 with a Coulombic efficiency of above 99.8% at 5 A g-1 at 80 °C, indicating its development prospects in high-performance SIB applications.
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Affiliation(s)
- Dingcheng Yang
- Department of Nano Fusion Technology, Pusan National University, Busan 46241, Republic of Korea
| | - Dolly Yadav
- Department of Nano Fusion Technology, Pusan National University, Busan 46241, Republic of Korea
- Crystal Bank Institute, Pusan National University, Busan 46241, Republic of Korea
| | - Injun Jeon
- Department of Nano Fusion Technology, Pusan National University, Busan 46241, Republic of Korea
| | - Jangwon Seo
- Department of Nano Fusion Technology, Pusan National University, Busan 46241, Republic of Korea
| | - Se-Young Jeong
- Crystal Bank Institute, Pusan National University, Busan 46241, Republic of Korea
- Department of Opto-Mechatronics Engineering, Pusan National University, Busan 46241, Republic of Korea
| | - Chae Ryong Cho
- Department of Nano Fusion Technology, Pusan National University, Busan 46241, Republic of Korea
- Crystal Bank Institute, Pusan National University, Busan 46241, Republic of Korea
- Department of Nanoenergy Engineering, Pusan National University, Busan 46241, Republic of Korea
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6
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Kim SJ, Kim YI, Lamichhane B, Kim YH, Lee Y, Cho CR, Cheon M, Kim JC, Jeong HY, Ha T, Kim J, Lee YH, Kim SG, Kim YM, Jeong SY. Flat-surface-assisted and self-regulated oxidation resistance of Cu(111). Nature 2022; 603:434-438. [PMID: 35296844 PMCID: PMC8930770 DOI: 10.1038/s41586-021-04375-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 12/20/2021] [Indexed: 11/09/2022]
Abstract
Oxidation can deteriorate the properties of copper that are critical for its use, particularly in the semiconductor industry and electro-optics applications1–7. This has prompted numerous studies exploring copper oxidation and possible passivation strategies8. In situ observations have, for example, shown that oxidation involves stepped surfaces: Cu2O growth occurs on flat surfaces as a result of Cu adatoms detaching from steps and diffusing across terraces9–11. But even though this mechanism explains why single-crystalline copper is more resistant to oxidation than polycrystalline copper, the fact that flat copper surfaces can be free of oxidation has not been explored further. Here we report the fabrication of copper thin films that are semi-permanently oxidation resistant because they consist of flat surfaces with only occasional mono-atomic steps. First-principles calculations confirm that mono-atomic step edges are as impervious to oxygen as flat surfaces and that surface adsorption of O atoms is suppressed once an oxygen face-centred cubic (fcc) surface site coverage of 50% has been reached. These combined effects explain the exceptional oxidation resistance of ultraflat Cu surfaces. The fabrication of copper thin films with ultraflat surfaces and only occasional mono-atomic steps, which show semi-permanent resistance to oxidation over long periods, is reported and the mechanism explained using first-principles calculations.
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Affiliation(s)
- Su Jae Kim
- Crystal Bank Research Institute, Pusan National University, Busan, Republic of Korea
| | - Yong In Kim
- Department of Energy Science, Sungkyunkwan University, Suwon, Republic of Korea
| | - Bipin Lamichhane
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, MS, USA
| | - Young-Hoon Kim
- Department of Energy Science, Sungkyunkwan University, Suwon, Republic of Korea
| | - Yousil Lee
- Crystal Bank Research Institute, Pusan National University, Busan, Republic of Korea
| | - Chae Ryong Cho
- Department of Nanoenergy Engineering, Pusan National University, Busan, Republic of Korea
| | - Miyeon Cheon
- Crystal Bank Research Institute, Pusan National University, Busan, Republic of Korea
| | - Jong Chan Kim
- School of Materials Science and Engineering, Ulsan National Institute of Science and Technology, Ulsan, South Korea
| | - Hu Young Jeong
- UNIST Central Research Facilities (UCRF), Ulsan National Institute of Science and Technology, Ulsan, South Korea
| | - Taewoo Ha
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Sungkyunkwan University, Suwon, Republic of Korea
| | - Jungdae Kim
- Department of Physics, University of Ulsan, Ulsan, Republic of Korea
| | - Young Hee Lee
- Department of Energy Science, Sungkyunkwan University, Suwon, Republic of Korea.,Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Sungkyunkwan University, Suwon, Republic of Korea.,Department of Physics, Sungkyunkwan University, Suwon, Republic of Korea
| | - Seong-Gon Kim
- Department of Physics and Astronomy, Mississippi State University, Mississippi State, MS, USA.
| | - Young-Min Kim
- Department of Energy Science, Sungkyunkwan University, Suwon, Republic of Korea. .,Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Sungkyunkwan University, Suwon, Republic of Korea.
| | - Se-Young Jeong
- Department of Optics and Mechatronics Engineering, Pusan National University, Busan, Republic of Korea. .,Department of Cogno-Mechatronics Engineering, Pusan National University, Busan, Republic of Korea.
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Yin L, Cho J, Kim SJ, Jeon I, Jeon I, Park M, Park M, Jeong SY, Lee DH, Seo DH, Cho CR. Abnormally High-Lithium Storage in Pure Crystalline C 60 Nanoparticles. Adv Mater 2021; 33:e2104763. [PMID: 34510588 DOI: 10.1002/adma.202104763] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 08/01/2021] [Indexed: 06/13/2023]
Abstract
Li+ intercalates into a pure face-centered-cubic (fcc) C60 structure instead of being adsorbed on a single C60 molecule. This hinders the excess storage of Li ions in Li-ion batteries, thereby limiting their applications. However, the associated electrochemical processes and mechanisms have not been investigated owing to the low electrochemical reactivity and poor crystallinity of the C60 powder. Herein, a facile method for synthesizing pure fcc C60 nanoparticles with uniform morphology and superior electrochemical performance in both half- and full-cells is demonstrated using a 1 m LiPF6 solution in ethylene carbonate/diethyl carbonate (1:1 vol%) with 10% fluoroethylene carbonate. The specific capacity of the C60 nanoparticles during the second discharge reaches ≈750 mAh g-1 at 0.1 A g-1 , approximately twice that of graphite. Moreover, by applying in situ X-ray diffraction, high-resolution transmission electron microscopy, and first-principles calculations, an abnormally high Li storage in a crystalline C60 structure is proposed based on the vacant sites among the C60 molecules, Li clusters at different sites, and structural changes during the discharge/charge process. The fcc of C60 transforms tetragonal via orthorhombic Lix C60 and back to the cubic phase during discharge. The presented results will facilitate the development of novel fullerene-based anode materials for Li-ion batteries.
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Affiliation(s)
- Linghong Yin
- Department of Nano Fusion Technology, Pusan National University, Busan, 46241, Republic of Korea
| | - Jiung Cho
- Western-Seoul Center, Korea Basic Science Institute, Seoul, 03759, Republic of Korea
| | - Su Jae Kim
- Crystal Bank Research Institute, Pusan National University, Busan, 46241, Republic of Korea
| | - Il Jeon
- Sustainable Utilization of Photovoltaic Energy Research Center, Pusan National University, Busan, 46241, Republic of Korea
- Department of Chemistry Education, Graduate Department of Chemical Materials, Pusan National University, Busan, 46241, Republic of Korea
| | - Injun Jeon
- Department of Nano Fusion Technology, Pusan National University, Busan, 46241, Republic of Korea
| | - Mihee Park
- Sustainable Utilization of Photovoltaic Energy Research Center, Pusan National University, Busan, 46241, Republic of Korea
| | - Minjoon Park
- Department of Nano Fusion Technology, Pusan National University, Busan, 46241, Republic of Korea
- Department of Nanoenergy Engineering, Pusan National University, Busan, 46241, Republic of Korea
| | - Se-Young Jeong
- Crystal Bank Research Institute, Pusan National University, Busan, 46241, Republic of Korea
- Department of Opto-Mechatronics Engineering, Pusan National University, Busan, 46241, Republic of Korea
| | - Dae Hyung Lee
- Department of Energy Engineering, School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology, Ulsan, 44919, Republic of Korea
| | - Dong-Hwa Seo
- Department of Energy Engineering, School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology, Ulsan, 44919, Republic of Korea
| | - Chae-Ryong Cho
- Department of Nano Fusion Technology, Pusan National University, Busan, 46241, Republic of Korea
- Department of Nanoenergy Engineering, Pusan National University, Busan, 46241, Republic of Korea
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8
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Cho Y, Jung HR, Kim YS, Kim Y, Park J, Yoon S, Lee Y, Cheon M, Jeong SY, Jo W. High speed growth of MAPbBr 3 single crystals via low-temperature inverting solubility: enhancement of mobility and trap density for photodetector applications. Nanoscale 2021; 13:8275-8282. [PMID: 33890603 DOI: 10.1039/d1nr01600h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
There has been growing interest in organic-inorganic hybrid perovskites as a promising candidate for optoelectronic applications due to their superior physical properties. Despite this, most of the reported perovskite devices based on polycrystalline thin films suffer immensely from poor stability and high trap density owing to grain boundaries limiting their performance. Perovskite single crystal structures have been recently explored to construct stable devices and reduce the trap density compared to their thin-film counterparts. We present a novel method of growing sizable CH3NH3PbBr3 single crystals based on the high solubility characteristic of hybrid perovskites at low temperatures within inverse temperature crystallization. We compared both the crystallinity of perovskite single crystal structures and optoelectronic charge transport of single crystal photodetectors as a function of dissolution temperature. The performance of the photodetector fabricated with our large-scaled single crystal with high quality demonstrated low trap density, high mobility, and high photoresponse.
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Affiliation(s)
- Yunae Cho
- Department of Physics, Ewha Womans University, Korea.
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Kim SJ, Kim S, Lee J, Jo Y, Seo YS, Lee M, Lee Y, Cho CR, Kim JP, Cheon M, Hwang J, Kim YI, Kim YH, Kim YM, Soon A, Choi M, Choi WS, Jeong SY, Lee YH. Color of Copper/Copper Oxide. Adv Mater 2021; 33:e2007345. [PMID: 33751679 DOI: 10.1002/adma.202007345] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 01/30/2021] [Indexed: 06/12/2023]
Abstract
Stochastic inhomogeneous oxidation is an inherent characteristic of copper (Cu), often hindering color tuning and bandgap engineering of oxides. Coherent control of the interface between metal and metal oxide remains unresolved. Coherent propagation of an oxidation front in single-crystal Cu thin film is demonstrated to achieve a full-color spectrum for Cu by precisely controlling its oxide-layer thickness. Grain-boundary-free and atomically flat films prepared by atomic-sputtering epitaxy allow tailoring of the oxide layer with an abrupt interface via heat treatment with a suppressed temperature gradient. Color tuning of nearly full-color red/green/blue indices is realized by precise control of the oxide-layer thickness; the samples cover ≈50.4% of the standard red/green/blue color space. The color of copper/copper oxide is realized by the reconstruction of the quantitative yield color from the oxide "pigment" (complex dielectric functions of Cu2 O) and light-layer interference (reflectance spectra obtained from the Fresnel equations) to produce structural color. Furthermore, laser-oxide lithography is demonstrated with micrometer-scale linewidth and depth through local phase transformation to oxides embedded in the metal, providing spacing necessary for semiconducting transport and optoelectronics functionality.
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Affiliation(s)
- Su Jae Kim
- Crystal Bank Research Institute, Pusan National University, Busan, 46241, Republic of Korea
| | - Seonghoon Kim
- Research Institute of Basic Science, Seoul National University, Seoul, 08826, Republic of Korea
| | - Jegon Lee
- Department of Physics, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Yongjae Jo
- Center for Neurscience Imaging Research, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Yu-Seong Seo
- Department of Physics, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Myounghoon Lee
- Department of Physics, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Yousil Lee
- Crystal Bank Research Institute, Pusan National University, Busan, 46241, Republic of Korea
| | - Chae Ryong Cho
- Department of Nanoenergy Engineering, Pusan National University, Busan, 46241, Republic of Korea
| | - Jong-Pil Kim
- Division of High-Tech Materials Research, Busan Center, Korea Basic Science Institute, Busan, 46742, Republic of Korea
| | - Miyeon Cheon
- Crystal Bank Research Institute, Pusan National University, Busan, 46241, Republic of Korea
| | - Jungseek Hwang
- Department of Physics, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Yong In Kim
- Center for Integrated Nanostructure Physics, Institute for Basic Science, Sungkyunkwan University, Suwon, 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Young-Hoon Kim
- Center for Integrated Nanostructure Physics, Institute for Basic Science, Sungkyunkwan University, Suwon, 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Young-Min Kim
- Center for Integrated Nanostructure Physics, Institute for Basic Science, Sungkyunkwan University, Suwon, 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Aloysius Soon
- Center for Artificial Synesthesia Materials Discovery and Department of Materials Science and Engineering, Yonsei University, Seoul, 03722, Republic of Korea
| | - Myunghwan Choi
- School of Biological Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Woo Seok Choi
- Department of Physics, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Se-Young Jeong
- Center for Integrated Nanostructure Physics, Institute for Basic Science, Sungkyunkwan University, Suwon, 16419, Republic of Korea
- Department of Optics and Mechatronics Engineering, Pusan National University, Busan, 46241, Republic of Korea
| | - Young Hee Lee
- Center for Integrated Nanostructure Physics, Institute for Basic Science, Sungkyunkwan University, Suwon, 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, Republic of Korea
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Nguyen VL, Duong DL, Lee SH, Avila J, Han G, Kim YM, Asensio MC, Jeong SY, Lee YH. Author Correction: Layer-controlled single-crystalline graphene film with stacking order via Cu-Si alloy formation. Nat Nanotechnol 2021; 16:114-116. [PMID: 33288950 DOI: 10.1038/s41565-020-00821-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Affiliation(s)
- Van Luan Nguyen
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon, Republic of Korea
- Inorganic Materials Laboratory, Samsung Advanced Institute of Technology, Samsung Electronics, Suwon, Korea
| | - Dinh Loc Duong
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon, Republic of Korea
- Department of Energy Science, Department of Physics, Sungkyunkwan University, Suwon, Korea
| | - Sang Hyub Lee
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon, Republic of Korea
- Department of Energy Science, Department of Physics, Sungkyunkwan University, Suwon, Korea
| | - José Avila
- Synchrotron SOLEIL, Université Paris-Saclay, L'Orme des Merisiers Saint-Aubin, Gif sur Yvette, France
| | - Gyeongtak Han
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon, Republic of Korea
| | - Young-Min Kim
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon, Republic of Korea
- Department of Energy Science, Department of Physics, Sungkyunkwan University, Suwon, Korea
| | - Maria C Asensio
- Materials Science Institute of Madrid (ICMM), Spanish Scientific Research Council (CSIC), Cantoblanco, Madrid, Spain.
- MATINÉE: CSIC Associated Unit (ICMM-ICMUV Valencia University), Cantoblanco, Madrid, Spain.
| | - Se-Young Jeong
- Department of Cogno-mechatronics Engineering, Department of Optics and Mechatronics Engineering, Pusan National University, Busan, Republic of Korea.
| | - Young Hee Lee
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon, Republic of Korea.
- Department of Energy Science, Department of Physics, Sungkyunkwan University, Suwon, Korea.
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Nguyen VL, Duong DL, Lee SH, Avila J, Han G, Kim YM, Asensio MC, Jeong SY, Lee YH. Layer-controlled single-crystalline graphene film with stacking order via Cu-Si alloy formation. Nat Nanotechnol 2020; 15:861-867. [PMID: 32719494 DOI: 10.1038/s41565-020-0743-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 06/24/2020] [Indexed: 06/11/2023]
Abstract
Multilayer graphene and its stacking order provide both fundamentally intriguing properties and technological engineering applications. Several approaches to control the stacking order have been demonstrated, but a method of precisely controlling the number of layers with desired stacking sequences is still lacking. Here, we propose an approach for controlling the layer thickness and crystallographic stacking sequence of multilayer graphene films at the wafer scale via Cu-Si alloy formation using direct chemical vapour deposition. C atoms are introduced by tuning the ultra-low-limit CH4 concentration to form a SiC layer, reaching one to four graphene layers at the wafer scale after Si sublimation. The crystallographic structure of single-crystalline or uniformly oriented bilayer (AB), trilayer (ABA) and tetralayer (ABCA) graphene are determined via nano-angle-resolved photoemission spectroscopy, which agrees with theoretical calculations, Raman spectroscopy and transport measurements. The present study takes a step towards the layer-controlled growth of graphite and other two-dimensional materials.
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Affiliation(s)
- Van Luan Nguyen
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon, Republic of Korea
- Inorganic Materials Laboratory, Samsung Advanced Institute of Technology, Samsung Electronics, Suwon, Korea
| | - Dinh Loc Duong
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon, Republic of Korea
- Department of Energy Science, Department of Physics, Sungkyunkwan University, Suwon, Korea
| | - Sang Hyub Lee
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon, Republic of Korea
- Department of Energy Science, Department of Physics, Sungkyunkwan University, Suwon, Korea
| | - José Avila
- Synchrotron SOLEIL, Université Paris-Saclay, L'Orme des Merisiers Saint-Aubin, Gif sur Yvette, France
| | - Gyeongtak Han
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon, Republic of Korea
| | - Young-Min Kim
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon, Republic of Korea
- Department of Energy Science, Department of Physics, Sungkyunkwan University, Suwon, Korea
| | - Maria C Asensio
- Materials Science Institute of Madrid (ICMM), Spanish Scientific Research Council (CSIC), Cantoblanco, Madrid, Spain.
- MATINÉE: CSIC Associated Unit (ICMM-ICMUV Valencia University), Cantoblanco, Madrid, Spain.
| | - Se-Young Jeong
- Department of Cogno-mechatronics Engineering, Department of Optics and Mechatronics Engineering, Pusan National University, Busan, Republic of Korea.
| | - Young Hee Lee
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon, Republic of Korea.
- Department of Energy Science, Department of Physics, Sungkyunkwan University, Suwon, Korea.
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Nation HL, Jeong SY, Jeong SW, Occhialini AP. Anomalous muscles and nerves in the hand of a 94-year-old cadaver-A case report. Int J Surg Case Rep 2019; 65:119-123. [PMID: 31704662 PMCID: PMC6920165 DOI: 10.1016/j.ijscr.2019.10.062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 10/23/2019] [Accepted: 10/24/2019] [Indexed: 11/18/2022] Open
Abstract
The additional flexor muscle (Flexor Digiti Minimi Longus m.) passing through Guyon’s canal is the first to be described. The anomalous first lumbrical muscle with three origins is the first to be described. Berretini’s and Kaplan’s anastomosis was also noted.
Introduction During an anatomical dissection of the distal upper extremities, numerous muscular and nervous anomalies were found in the forearm and hand of a 94-year-old cadaver. These anomalies are clinically relevant with regard to medical or surgical interventions. Presentation of case The presence of a “flexor digiti minimi longus” muscle was observed passing through Guyon’s canal; to our knowledge this passageway has never been previously reported. An aberrant first lumbrical with three origins was noted. Additionally, numerous atypical nerves were found innervating the hand; the dorsal branch of the ulnar nerve contributed to cutaneous innervation of the palm of the hand (Kaplan’s anastomosis), the superficial ulnar nerve provided muscular innervation to the flexor digiti minimi brevis muscle, and two connections between the common palmar digital branches of the median and superficial ulnar nerves were observed (Berrettini anastomosis). Discussion Here, we describe an extranumerary muscle associated with the hypothenar group of muscles. We also describe unusual origins of the first lumbrical muscle, and atypical cutaneous and muscular innervation to the palm of the hand. Conclusion Clinically, understanding the existence of these anatomical variations may influence medical care or surgical procedures.
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Affiliation(s)
- H L Nation
- Department of Cell Systems and Anatomy, University of Texas-Health at San Antonio, 7703 Floyd Curl Dr, San Antonio, TX 78229, United States.
| | - S Y Jeong
- Long School of Medicine, University of Texas-Health at San Antonio, 7703 Floyd Curl Dr, San Antonio, TX 78229, United States.
| | - S W Jeong
- Long School of Medicine, University of Texas-Health at San Antonio, 7703 Floyd Curl Dr, San Antonio, TX 78229, United States.
| | - A P Occhialini
- Department of Cell Systems and Anatomy, University of Texas-Health at San Antonio, 7703 Floyd Curl Dr, San Antonio, TX 78229, United States.
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Jeong SY, Kang ML, Park JW, Im GI. Dual functional nanoparticles containing SOX duo and ANGPT4 shRNA for osteoarthritis treatment. J Biomed Mater Res B Appl Biomater 2019; 108:234-242. [PMID: 30957437 DOI: 10.1002/jbm.b.34383] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2018] [Revised: 03/09/2019] [Accepted: 03/24/2019] [Indexed: 12/15/2022]
Abstract
In our previous studies, we found that adult stem cells transfected with sex-determining region Y-box (SOX)-9, -6 and -5 genes (SOX trio) enhanced chondrogenesis and suppressed the progression of osteoarthritis (OA). The inhibition of angiopoietin-like 4 (ANGPT4) is known to reduce levels of cartilage damaging enzymes, such as, matrix metalloproteinases (MMPs). In this study, we designed nanoparticles comprising dexamethasone-conjugated polyethylenimine (DEX PEI) complexed with minicircle plasmid (MC) harboring SOX duo (SOX-9, -6) and ANGPTL4 small hairpin RNA (shANG) [MC SOX9/6/shANG] in the expectation that transfection of these nanoparticles would enhance chondrogenesis of stem cells and suppress inflammation in OA. Adipose-derived stem cells (ADSCs) transfected with MC SOX9/6/shANG (MC SOX9/6/shANG-tADSCs) showed significantly higher expressions of COL2 gene and protein than MC SOX9/6-transfected ADSCs (MC SOX9/6-tADSCs) during in vitro chondrogenesis while both enhanced chondrogenesis in the absence of growth factor addition as compared with negative controls. Furthermore, the expressions of MMP13 and MMP3 genes were significantly more diminished in MC SOX9/6/shANG-tADSCs than in MC SOX9/6-tADSCs. In vivo experiments using surgically-induced OA rats showed MC SOX9/6/shANG-tADSC-treated rats had significantly lower levels of cyclooxygenase (COX-2) and MMP13 in synovial fluids than MC SOX9/6-tADSC-treated rats, but no significant difference was observed between them in histological appearances. Both groups showed significantly less joint destruction than control groups did. These results demonstrate that dual functional nanoparticles containing SOX duo and ANGPT4 shRNA enhance chondrogenesis of ADSCs and suppress inflammation in OA. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 108B:234-242, 2020.
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Affiliation(s)
- Se-Young Jeong
- Integrative Research Institute for Regenerative Medical Engineering, Dongguk University, 814 Siksa-Dong, 411-773, Goyang, Republic of Korea
| | - Mi-Lan Kang
- Integrative Research Institute for Regenerative Medical Engineering, Dongguk University, 814 Siksa-Dong, 411-773, Goyang, Republic of Korea
| | - Jeong-Won Park
- Integrative Research Institute for Regenerative Medical Engineering, Dongguk University, 814 Siksa-Dong, 411-773, Goyang, Republic of Korea
| | - Gun-Il Im
- Integrative Research Institute for Regenerative Medical Engineering, Dongguk University, 814 Siksa-Dong, 411-773, Goyang, Republic of Korea
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Cheon M, Cho Y, Park CH, Cho CR, Jeong SY. A study of the density of states of ZnCoO:H from resistivity measurements. RSC Adv 2018; 8:9895-9900. [PMID: 35540802 PMCID: PMC9078852 DOI: 10.1039/c7ra12866e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 02/17/2018] [Indexed: 02/02/2023] Open
Abstract
Understanding the electronic band structure and density of states (DOS) of a material and their relationship to the associated electronic transport properties is the starting point for optimizing the performance of a device and its technological applications. In a hydrogenated Zn0.8Co0.2O (ZnCoO:H) film with an inverted thin-film transistor structure, we found ambipolar behavior, which is shown in many field-effect devices based on graphene, graphene nanoribbons, and organic semiconductors. In this study, to obtain information on the DOS of ZnCoO:H to explain the ambipolar behavior in terms of the carrier density and type, resistivity and magnetoresistance measurements of a ZnCoO:H film were performed at 5 K. Our proposed DOS representation of ZnCoO:H explains qualitatively the experimental observations of carrier density modulation and ambipolar behavior. First-principles calculations of the DOS of ZnCoO:H were in good agreement with the proposed DOS representation. Through a comparison of first-principles calculations and experimental data, evidence for the existence of Co–H–Co in ZnCoO:H is suggested. Ambipolar behavior in a hydrogenated Zn0.8Co0.2O (ZnCoO:H) film is investigated via resistivity and magnetoresistance measurements and first-principles calculations of the DOS. Evidence for the existence of Co–H–Co in ZnCoO:H is suggested.![]()
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Affiliation(s)
- Miyeon Cheon
- Crystal Bank Research Institute, Pusan National University Miryang 50463 Korea
| | - Yong Cho
- Korea Research Institute of Standards and Science Daejeon 34113 Korea
| | - Chul-Hong Park
- Dept. of Physics Education, Pusan National University Busan 46241 Korea
| | - Chae Ryong Cho
- Department of Nanoenergy Engineering, College of Nanoscience and Nanotechnology, Pusan National University Busan 46241 Republic of Korea
| | - Se-Young Jeong
- Dept. of Cogno-Mechatronics Engineering, Pusan National University Busan 46241 Korea +82-55-353-1314 +82-55-350-5273.,Dept. of Optics and Mechatronics Engineering, Pusan National University Miryang 50463 Korea
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Kang ML, Kim EA, Jeong SY, Im GI. Angiopoietin-2 Enhances Osteogenic Differentiation of Bone Marrow Stem Cells. J Cell Biochem 2017; 118:2896-2908. [PMID: 28214341 DOI: 10.1002/jcb.25940] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2016] [Accepted: 02/16/2017] [Indexed: 12/24/2022]
Abstract
Our previous studies revealed that co-transplantation of bone marrow stem cells (BMSCs) and adipose-derived stem cells (ADSCs) can enhance bone regeneration and angiogenesis. However, it is unclear which genes are involved in the regulation of osteogenesis and/or angiogenesis during the co-culturing of BMSCs and ADSCs. The expression patterns of genes associated with osteogenesis and/or angiogenesis were analyzed in osteogenesis-induced BMSCs and ADSCs using an oligonucleotide microarray. Significant difference in the expression patterns of several genes were identified from hierarchical clustering and analyzed on co-cultured BMSCs and ADSCs. Angiopoietin-2 (ANGPT2) and activin receptor-like kinase-1 were significantly down-regulated in co-culture than culture of either BMSCs or ADSCs, while fibroblast growth factor-9 was significantly up-regulated in co-culture. The effect of ANGPT2 in osteogenesis-induced BMSCs was validated using recombinant protein and siRNA of ANGPT2. Treatment of the ANGPT2 protein significantly increased the expressions of osteogenic makers and the intensity of Alizarin red-S staining in BMSCs. Down-regulation of ANGPT2 significantly decreased the expression of osteogenic makers. The treatment of ANGPT2 protein to BMSCs induced significantly increased tube formation in Transwell-co-cultured human umbilical vein endothelial cells (HUVECs) compared with untreated control. ANGPT2 siRNA transfection showed the opposite effects. These results suggest that the treatment of ANGPT2 in BMSCs increase osteogenesis and angiogenesis in vitro, and that the enhancement of osteogenesis and angiogenesis in the co-cultured BMSCs and ADSCs seems to be mediated by a mechanism that makes the activation of ANGPT2 unnecessary. These observations provide the first evidence for positive regulation of osteogenesis by ANGPT2 in vitro. J. Cell. Biochem. 118: 2896-2908, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Mi-Lan Kang
- Department of Orthopedics, Dongguk University Ilsan Hospital, Goyang, Republic of Korea
| | - Eun-Ah Kim
- Department of Orthopedics, Dongguk University Ilsan Hospital, Goyang, Republic of Korea
| | - Se-Young Jeong
- Department of Orthopedics, Dongguk University Ilsan Hospital, Goyang, Republic of Korea
| | - Gun-Il Im
- Department of Orthopedics, Dongguk University Ilsan Hospital, Goyang, Republic of Korea
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Pham-Cong D, Kim J, Tran VT, Kim SJ, Jeong SY, Choi JH, Cho CR. Electrochemical behavior of interconnected Ti 2 Nb 10 O 29 nanoparticles for high-power Li-ion battery anodes. Electrochim Acta 2017. [DOI: 10.1016/j.electacta.2017.03.203] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Kang ML, Jeong SY, Im GI. Hyaluronic Acid Hydrogel Functionalized with Self-Assembled Micelles of Amphiphilic PEGylated Kartogenin for the Treatment of Osteoarthritis. Tissue Eng Part A 2017; 23:630-639. [PMID: 28338415 DOI: 10.1089/ten.tea.2016.0524] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Synthetic hyaluronic acid (HA) containing a covalently integrated drug is capable of releasing therapeutic molecules and is an attractive candidate for the intra-articular treatment of osteoarthritis (OA). Herein, self-assembled PEGylated kartogenin (PEG/KGN) micelles consisting of hydrophilic polyethylene glycol (PEG) and hydrophobic KGN, which has been shown to induce chondrogenesis in human mesenchymal stem cells, were prepared by covalent crosslinking. HA hydrogels containing PEG/KGN micelles (HA/PEG/KGN) were prepared by covalently bonding PEG chains to HA. The physicochemical properties of the HA/PEG/KGN conjugate gels were investigated using Fourier transform infrared spectroscopy, 1H NMR, dynamic light scattering (DLS), and scanning electron microscopy (SEM). HA/PEG/KGN gels exhibited larger micelles in aqueous solution than PEG/KGN. SEM images of PEG/KGN micelles showed a dark core and a bright shell, whereas PEG/KGN micelles covalently integrated into HA had an irregular oval shape. Covalent integration of PEG/KGN micelles in HA hydrogels significantly reduced drug release rates and provided sustained release over a prolonged period of time. HA/PEG/KGN hydrogels were degradable enzymatically by collagenase and hyaluronidase in vitro. Injection of HA/PEG/KGN hydrogels into articular cartilage significantly suppressed the progression of OA in rats compared with free-HA hydrogel injection. These results suggest that the HA/PEG/KGN hydrogels have greater potency than free-HA hydrogels against OA as biodegradable synthetic therapeutics.
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Affiliation(s)
- Mi-Lan Kang
- Department of Orthopedics, Dongguk University Ilsan Hospital , Goyang, Republic of Korea
| | - Se-Young Jeong
- Department of Orthopedics, Dongguk University Ilsan Hospital , Goyang, Republic of Korea
| | - Gun-Il Im
- Department of Orthopedics, Dongguk University Ilsan Hospital , Goyang, Republic of Korea
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Nguyen VL, Perello DJ, Lee S, Nai CT, Shin BG, Kim JG, Park HY, Jeong HY, Zhao J, Vu QA, Lee SH, Loh KP, Jeong SY, Lee YH. Wafer-Scale Single-Crystalline AB-Stacked Bilayer Graphene. Adv Mater 2016; 28:8177-8183. [PMID: 27414480 DOI: 10.1002/adma.201601760] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 06/19/2016] [Indexed: 06/06/2023]
Abstract
Single-crystalline artificial AB-stacked bilayer graphene is formed by aligned transfer of two single-crystalline monolayers on a wafer-scale. The obtained bilayer has a well-defined interface and is electronically equivalent to exfoliated or direct-grown AB-stacked bilayers.
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Affiliation(s)
- Van Luan Nguyen
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Sungkyunkwan University, Suwon, 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, Republic of Korea
- Department of Physics, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - David J Perello
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Seunghun Lee
- Department of Cogno-mechatronics Engineering, Pusan National University, Busan, 46241, Republic of Korea
| | - Chang Tai Nai
- Department of Chemistry and Centre for Advanced 2D Materials (CA2DM), National University of Singapore, 3 Science Drive 3, Singapore, 117543
| | - Bong Gyu Shin
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Joong-Gyu Kim
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Sungkyunkwan University, Suwon, 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, Republic of Korea
- Department of Physics, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Ho Yeol Park
- Department of Cogno-mechatronics Engineering, Pusan National University, Busan, 46241, Republic of Korea
| | - Hu Young Jeong
- UNIST Central Research Facilities, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 689-798, Republic of Korea
| | - Jiong Zhao
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Quoc An Vu
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Sungkyunkwan University, Suwon, 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, Republic of Korea
- Department of Physics, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Sang Hyub Lee
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Sungkyunkwan University, Suwon, 16419, Republic of Korea
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, Republic of Korea
- Department of Physics, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Kian Ping Loh
- Department of Chemistry and Centre for Advanced 2D Materials (CA2DM), National University of Singapore, 3 Science Drive 3, Singapore, 117543
| | - Se-Young Jeong
- Department of Cogno-mechatronics Engineering, Pusan National University, Busan, 46241, Republic of Korea.
| | - Young Hee Lee
- Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Sungkyunkwan University, Suwon, 16419, Republic of Korea.
- Department of Energy Science, Sungkyunkwan University, Suwon, 16419, Republic of Korea.
- Department of Physics, Sungkyunkwan University, Suwon, 16419, Republic of Korea.
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Choi YK, Jeong SY, Sim BC. Effect of pressure and temperature on bulk micro defect and denuded zone in nitrogen ambient furnace. Journal of the Korean Crystal Growth and Crystal Technology 2016. [DOI: 10.6111/jkcgct.2016.26.3.121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Abstract
The magnetoresistance (MR) of ZnCoO:H was measured at 7 K to verify the MR dependency on carrier density. It was found that MR increased with negative gate voltage. This increase in MR is not caused by an increase in pMR, but by a decrease in nMR.
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Affiliation(s)
- Miyeon Cheon
- Crystal Bank Research Institute
- Pusan National University
- Miryang
- Republic of Korea
| | - Yong Chan Cho
- Korea Research Institute of Standard and Science
- Daejeon 34113
- Republic of Korea
| | - Chae-Ryong Cho
- Department of Nanoenergy Engineering
- Pusan National University
- Busan 46241
- Republic of Korea
| | - Chul Hong Park
- Department of Physics Education
- Pusan National University
- Busan
- Republic of Korea
| | - Se-Young Jeong
- Department of Cogno-Mechatronics Engineering
- Pusan National University
- Busan
- Republic of Korea
- Department of Optics and Mechatronics Engineering
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Lee S, Park JH, Kim WK, Park HD, Lee BC, Moriyoshi C, Kuroiwa Y, Lee GW, Chan Cho Y, Jeong SY. Control of magneto-transport characteristics of Co-doped ZnO by electron beam irradiation. RSC Adv 2016. [DOI: 10.1039/c6ra02641a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Electron beam irradiation can be used to remove shallow donor type hydrogen located in Zn(Co)–O bonding centers in Co-doped ZnO, which enables to modify the conduction band and the magneto-transport characteristics of Co-doped ZnO.
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Affiliation(s)
- Seunghun Lee
- Department of Materials Science and Engineering
- University of Maryland
- College Park
- USA
| | - Ji Hun Park
- Department of Cogno-Mechatronics Engineering
- Pusan National University
- Miryang
- Republic of Korea
| | - Won-Kyung Kim
- Department of Cogno-Mechatronics Engineering
- Pusan National University
- Miryang
- Republic of Korea
| | - Hyung Dal Park
- Radiation Instrumentation Research Division
- Korea Atomic Energy Research Institute (KAERI)
- Daejeon
- Republic of Korea
| | - Byung Cheol Lee
- Radiation Instrumentation Research Division
- Korea Atomic Energy Research Institute (KAERI)
- Daejeon
- Republic of Korea
| | - Chikako Moriyoshi
- Department of Physical Science
- Hiroshima University
- Higashihiroshima 739-8526
- Japan
| | - Yoshihiro Kuroiwa
- Department of Physical Science
- Hiroshima University
- Higashihiroshima 739-8526
- Japan
| | - Geun Woo Lee
- Frontier in Extreme Physics
- Korea Research Institute of Standards and Science
- Daejeon 305-340
- Republic of Korea
| | - Yong Chan Cho
- Frontier in Extreme Physics
- Korea Research Institute of Standards and Science
- Daejeon 305-340
- Republic of Korea
| | - Se-Young Jeong
- Department of Cogno-Mechatronics Engineering
- Pusan National University
- Miryang
- Republic of Korea
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Kim WK, Cheon M, Lee S, Lee TW, Park JJ, Cho CR, Park CH, Takeuchi I, Jeong SY. Magnetic domains in H-mediated Zn 0.9Co 0.1O microdisk arrays. RSC Adv 2016. [DOI: 10.1039/c6ra05746b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We have fabricated and studied magnetic domains in the periodic ZnCoO microdisk structures at room temperature with MFM technique. The z-component of the remanent magnetic moment is uniform even though the value is much smaller than the saturation magnetic moment.
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Affiliation(s)
- Won-Kyung Kim
- Department of Cogno-Mechatronics Engineering
- Pusan National University
- Miryang
- Republic of Korea
| | - Miyeon Cheon
- Crystal Bank Research Institute
- Pusan National University
- Miryang
- Republic of Korea
| | - Seunghun Lee
- Department of Materials Science and Engineering
- University of Maryland
- College Park
- USA
| | - Tae-Woo Lee
- KAIST Analysis Center for Research Advancement
- Daejeon
- Republic of Korea
| | - Jung Jin Park
- Department of Aerospace Engineering
- University of Maryland
- College Park
- USA
| | - Chae Ryong Cho
- Department of Nano Fusion Technology
- Pusan National University
- Miryang
- Republic of Korea
| | - Chul Hong Park
- Department of Physics Education
- Pusan National University
- Busan
- Republic of Korea
| | - Ichiro Takeuchi
- Department of Materials Science and Engineering
- University of Maryland
- College Park
- USA
| | - Se-Young Jeong
- Department of Cogno-Mechatronics Engineering
- Pusan National University
- Miryang
- Republic of Korea
- Department of Optics and Mechatronics Engineering
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Sim JA, Shin JS, Park SM, Chang YJ, Shin A, Noh DY, Han W, Yang HK, Lee HJ, Kim YW, Kim YT, Jeong SY, Yoon JH, Kim YJ, Heo DS, Kim TY, Oh DY, Wu HG, Kim HJ, Chie EK, Kang KW, Yun YH. Association between information provision and decisional conflict in cancer patients. Ann Oncol 2015; 26:1974-1980. [PMID: 26116430 DOI: 10.1093/annonc/mdv275] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 06/16/2015] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND In this study, we aimed to identify demographic and clinical variables that correlate with perceived information provision among cancer patients and determine the association of information provision with decisional conflict (DC). PATIENTS AND METHODS We enrolled a total of 625 patients with cancer from two Korean hospitals in 2012. We used the European Organization for Research and Treatment of Cancer (EORTC) quality-of-life questionnaire (QLQ-INFO26) to assess patients' perception of the information received from their doctors and the Decisional Conflict Scale (DCS) to assess DC. To identify predictive sociodemographic and clinical variables for adequate information provision, backward selective logistic regression analyses were conducted. In addition, adjusted multivariate logistic regression analyses were carried out to identify clinically meaningful differences of perceived level of information subscales associated with high DC. RESULTS More than half of patients with cancer showed insufficient satisfaction with medical information about disease (56%), treatment (73%), other services (83%), and global score (80%). In multiple logistic regression analyses, lower income and education, female, unmarried status, type of cancer with good prognosis, and early stage of treatment process were associated with patients' perception of inadequate information provision. In addition, Information about the medical tests with high DCS values clarity [adjusted odds ratio (aOR), 0.54; 95% confidence interval (CI) 0.30-0.97] and support (aOR, 0.53; 95% CI 0.33-0.85) showed negative significance. For inadequate information perception about treatments and other services, all 5 DCS scales (uncertainty, informed, values clarity, support, and effective decision) were negatively related. Global score of inadequate information provision also showed negative association with high DCS effective decision (aOR, 0.43; 95% CI 0.26-0.71) and DCS uncertainty (aOR, 0.46; 95% CI 0.27-0.77). CONCLUSION This study found that inadequate levels of perceived information correlated with several demographic and clinical characteristics. In addition, sufficient perceived information levels may be related to low levels of DC.
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Affiliation(s)
- J A Sim
- Department of Biomedical Science, Seoul National University College of Medicine, Seoul
| | - J S Shin
- Department of Biomedical Science, Seoul National University College of Medicine, Seoul; Department of Education & Human Resources Development, Seoul National University Hospital, Seoul, Korea
| | - S M Park
- Department of Biomedical Science, Seoul National University College of Medicine, Seoul
| | - Y J Chang
- Research Institute and Hospital, National Cancer Center, Goyang-si
| | - A Shin
- Department of Preventive Medicine
| | - D Y Noh
- Department of Cancer Research Institute, Seoul National University College of Medicine, Seoul;; Department of Surgery
| | - W Han
- Department of Cancer Research Institute, Seoul National University College of Medicine, Seoul;; Department of Surgery
| | - H K Yang
- Department of Cancer Research Institute, Seoul National University College of Medicine, Seoul;; Department of Surgery
| | - H J Lee
- Department of Cancer Research Institute, Seoul National University College of Medicine, Seoul;; Department of Surgery
| | - Y W Kim
- Department of Internal Medicine, Seoul National University College of Medicine and Hospital, Seoul
| | - Y T Kim
- Department of Cancer Research Institute, Seoul National University College of Medicine, Seoul;; Department of Thoracic and Cardiovascular Surgery, Seoul National University Hospital, Seoul
| | - S Y Jeong
- Department of Cancer Research Institute, Seoul National University College of Medicine, Seoul;; Department of Surgery
| | - J H Yoon
- Department of Internal Medicine, Seoul National University College of Medicine and Hospital, Seoul; Liver Research Institute, Seoul National University College of Medicine, Seoul
| | - Y J Kim
- Department of Internal Medicine, Seoul National University College of Medicine and Hospital, Seoul; Liver Research Institute, Seoul National University College of Medicine, Seoul
| | - D S Heo
- Department of Cancer Research Institute, Seoul National University College of Medicine, Seoul;; Department of Internal Medicine, Seoul National University College of Medicine and Hospital, Seoul
| | - T Y Kim
- Department of Cancer Research Institute, Seoul National University College of Medicine, Seoul;; Department of Internal Medicine, Seoul National University College of Medicine and Hospital, Seoul
| | - D Y Oh
- Department of Cancer Research Institute, Seoul National University College of Medicine, Seoul
| | - H G Wu
- Department of Cancer Research Institute, Seoul National University College of Medicine, Seoul;; Departments of Radiation Oncology
| | - H J Kim
- Departments of Radiation Oncology
| | - E K Chie
- Departments of Radiation Oncology
| | - K W Kang
- Department of Biomedical Science, Seoul National University College of Medicine, Seoul; Department of Cancer Research Institute, Seoul National University College of Medicine, Seoul;; Nuclear Medicine, Seoul National University College of Medicine and Hospital, Seoul
| | - Y H Yun
- Department of Biomedical Science, Seoul National University College of Medicine, Seoul; Department of Cancer Research Institute, Seoul National University College of Medicine, Seoul;.
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24
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Tran VT, Zhou H, Lee S, Hong SC, Kim J, Jeong SY, Lee J. Magnetic-assembly mechanism of superparamagneto-plasmonic nanoparticles on a charged surface. ACS Appl Mater Interfaces 2015; 7:8650-8658. [PMID: 25856000 DOI: 10.1021/acsami.5b00904] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
One-dimensional magnetoplasmonic nanochains (MPNCs) were self-assembled using Au-coated Fe3O4 core-shell superparamagnetic nanoparticles (Fe3O4@Au NPs) by applying an external static magnetic field. The assembly mechanism of the Fe3O4@Au NPs was investigated thoroughly, revealing that substrate-particle interactions, van der Waals forces, and magnetic forces play important roles in the formation and control of the MPNCs. Magnetic force microscopy (MFM) and vibrating sample magnetometry (VSM) were used to study the magnetic properties of the MPNCs, which were compared with those of Fe3O4 nanochains.
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Affiliation(s)
- Van Tan Tran
- †Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 609-735, Republic of Korea
| | - Hongjian Zhou
- §Key Laboratory of Materials Physics, Centre for Environmental and Energy Nanomaterials, Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, P. R. China
| | - Seunghun Lee
- †Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 609-735, Republic of Korea
| | - Seong Cheol Hong
- †Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 609-735, Republic of Korea
| | - Jeonghyo Kim
- †Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 609-735, Republic of Korea
| | - Se-Young Jeong
- †Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 609-735, Republic of Korea
| | - Jaebeom Lee
- †Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 609-735, Republic of Korea
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Pham-Cong D, Kim JY, Park JS, Kim JH, Kim JP, Jeong ED, Kim J, Jeong SY, Cho CR. Conductive framework supported high rate performance of SnO2 hollow nanofibers for lithium battery anodes. Electrochim Acta 2015. [DOI: 10.1016/j.electacta.2015.02.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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26
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Lee JH, Ahn K, Kim SH, Jeong SY, Bae JS, Hong TE, Kim HG, Cho CR. Efficiencies of Dye-Sensitized Solar Cells with Hollow SnO2 Nanofiber/TiO2 Nanoparticle Composite Photoanodes. J Nanosci Nanotechnol 2015; 15:244-247. [PMID: 26328340 DOI: 10.1166/jnn.2015.8399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In this study, we present dye-sensitized solar cells (DSSCs) with improved efficiencies by using SnO2/TiO2 composite photoanodes containing SnO2 at various concentrations. The composites consisted of hollow nanofibers (h-NFs) of SnO2 and TiO2 nanoparticles (NPs). The combination of the large surface area of the NPs and the efficient charge transport in the h-NFs make the use of the SnO2/TiO2 composites advantageous. DSSCs in which composite photoanodes with 50 wt% h-NFs were incorporated showed enhanced efficiencies that were 20% higher than the efficiencies of cells containing TiO2 NP-based photoanodes. These results indicated the improved electron diffusion length and shorter electron transfer time in the composite structures due to the crosslinking between h-NFs and NPs.
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27
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Park JH, Lee YJ, Bae JS, Kim BS, Cho YC, Moriyoshi C, Kuroiwa Y, Lee S, Jeong SY. Analysis of oxygen vacancy in Co-doped ZnO using the electron density distribution obtained using MEM. Nanoscale Res Lett 2015; 10:186. [PMID: 25977658 PMCID: PMC4414861 DOI: 10.1186/s11671-015-0887-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 03/31/2015] [Indexed: 05/22/2023]
Abstract
Oxygen vacancy (VO) strongly affects the properties of oxides. In this study, we used X-ray diffraction (XRD) to study changes in the VO concentration as a function of the Co-doping level of ZnO. Rietveld refinement yielded a different result from that determined via X-ray photoelectron spectroscopy (XPS), but additional maximum entropy method (MEM) analysis led it to compensate for the difference. VO tended to gradually decrease with increased Co doping, and ferromagnetic behavior was not observed regardless of the Co-doping concentration. MEM analysis demonstrated that reliable information related to the defects in the ZnO-based system can be obtained using X-ray diffraction alone.
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Affiliation(s)
- Ji Hun Park
- />Department of Cogno-Mechatronics Engineering, Pusan National University, Miryang, 627-706 South Korea
| | - Yeong Ju Lee
- />Department of Cogno-Mechatronics Engineering, Pusan National University, Miryang, 627-706 South Korea
- />Department of Nanofusion Engineering, Pusan National University, Busan, 609-735 South Korea
| | - Jong-Seong Bae
- />Busan Center, Korea Basic Science Institute, Busan, 618-230 South Korea
| | - Bum-Su Kim
- />Department of Cogno-Mechatronics Engineering, Pusan National University, Miryang, 627-706 South Korea
| | - Yong Chan Cho
- />Frontier in Extreme Physics, Korea Research Institute of Standards and Science, Daejeon, 305-340 South Korea
| | - Chikako Moriyoshi
- />Department of Physical Science, Hiroshima University, Higashi-Hiroshima, 739-8526 Japan
| | - Yoshihiro Kuroiwa
- />Department of Physical Science, Hiroshima University, Higashi-Hiroshima, 739-8526 Japan
| | - Seunghun Lee
- />The Institute of Basic Science, Korea University, Seoul, 136-713 Republic of Korea
- />Current address: Department of Materials Science and Engineering, University of Maryland, College Park, MD 20742 USA
| | - Se-Young Jeong
- />Department of Cogno-Mechatronics Engineering, Pusan National University, Miryang, 627-706 South Korea
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Lee S, Kim BS, Park JH, Lee TW, Chan Cho Y, Jeong SY. Study on the formation of magnetic nanoclusters and change in spin ordering in Co-doped ZnO using magnetic susceptibility. RSC Adv 2015. [DOI: 10.1039/c5ra13194d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The temperature-dependent magnetic susceptibility measurement could provide a useful methodological approach as well as experimental clues for identifying the origin of magnetism in magnetic semiconductor.
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Affiliation(s)
- Seunghun Lee
- Department of Materials Science and Engineering
- University of Maryland
- College Park
- USA
| | - Bum-Su Kim
- Department of Cogno-mechatronics Engineering
- Pusan National University
- Miryang
- Republic of Korea
| | - Ji Hun Park
- Department of Cogno-mechatronics Engineering
- Pusan National University
- Miryang
- Republic of Korea
| | - Tae-Woo Lee
- KAIST Analysis Center for Research Advancement
- Daejeon
- Republic of Korea
| | - Yong Chan Cho
- Korea Research Institute of Standards and Science
- Daejeon
- Republic of Korea
| | - Se-Young Jeong
- Department of Cogno-mechatronics Engineering
- Pusan National University
- Miryang
- Republic of Korea
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29
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Lee H, Shin JM, Cho YC, Lee S, Park CH, Park N, Jeong SY, Kim SY. p-type conductivity generated by ferromagnetic ordering via percolative anionic H chain formation in ZnCoO. J Phys Condens Matter 2014; 26:255501. [PMID: 24861274 DOI: 10.1088/0953-8984/26/25/255501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We report on the simultaneous realization of p-type conductivity and strong ferromagnetism in heavily Co-doped ZnO thin films in the presence of a high concentration of hydrogen impurities. Through ab initio calculations, we find that the microscopic origin of hole carrier generations and ferromagnetic ordering is due to the partially occupied band of the percolative structures wherein the carrier-induced magnetic interactions can stabilize the strong spin-parallel state.
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Affiliation(s)
- Hosik Lee
- School of Mechanical and Nuclear Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Korea
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30
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Kim BS, Lee S, Kim WK, Park JH, Cho YC, Kim J, Cho CR, Jeong SY. Fabrication of ZnCoO nanowires and characterization of their magnetic properties. Nanoscale Res Lett 2014; 9:221. [PMID: 24910575 PMCID: PMC4030288 DOI: 10.1186/1556-276x-9-221] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Accepted: 04/02/2014] [Indexed: 06/02/2023]
Abstract
Hydrogen-treated ZnCoO shows magnetic behavior, which is related to the formation of Co-H-Co complexes. However, it is not well known how the complexes are connected to each other and with what directional behavior they are ordered. In this point of view, ZnCoO nanowire is an ideal system for the study of the magnetic anisotropy. ZnCoO nanowire was fabricated by trioctylamine solution method under different ambient gases. We found that the oxidation of trioctylamine plays an essential role on the synthesis of high-quality ZnCoO nanowires. The hydrogen injection to ZnCoO nanowires induced ferromagnetism with larger magnetization than ZnCoO powders, while becoming paramagnetic after vacuum heat treatment. Strong ferromagnetism of nanowires can be explained by the percolation of Co-H-Co complexes along the c-axis.
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Affiliation(s)
- Bum-Su Kim
- Department of Cogno-Mechatronics Engineering, Pusan National University, 1268-50, Samnangin-ro, Samnangjin-eup, Miryang 627-706, Republic of Korea
| | - Seunghun Lee
- The Institute of Basic Science, Korea University, Seoul 136-713, Republic of Korea
| | - Won-Kyung Kim
- Department of Cogno-Mechatronics Engineering, Pusan National University, 1268-50, Samnangin-ro, Samnangjin-eup, Miryang 627-706, Republic of Korea
| | - Ji-Hun Park
- Department of Cogno-Mechatronics Engineering, Pusan National University, 1268-50, Samnangin-ro, Samnangjin-eup, Miryang 627-706, Republic of Korea
| | - Yong Chan Cho
- Crystal Bank Institute, Pusan National University, 1268-50, Samnangin-ro, Samnangjin-eup, Miryang 627-706, Republic of Korea
| | - Jungdae Kim
- Department of Physics, University of Ulsan, 93 Daehak-ro, Nam-gu, Ulsan 680-749, Republic of Korea
| | - Chae Ryong Cho
- Department of Nano Fusion Technology, Pusan National University, Samnangin-ro 1268-50, Republic of Korea
| | - Se-Young Jeong
- Department of Cogno-Mechatronics Engineering, Pusan National University, 1268-50, Samnangin-ro, Samnangjin-eup, Miryang 627-706, Republic of Korea
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Hong CM, Ahn BC, Jeong SY, Lee SW, Lee J. Distant metastatic lesions in patients with differentiated thyroid carcinoma. Clinical implications of radioiodine and FDG uptake. Nuklearmedizin 2014; 52:121-9. [PMID: 23928981 DOI: 10.3413/nukmed-0541-12-11] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Accepted: 05/27/2013] [Indexed: 01/09/2023]
Abstract
AIM Many investigators have reported an inverse relationship between iodine and glucose utilization of differentiated thyroid carcinoma (DTC) according to its degree of differentiation; however, not every DTC is compatible with this phenomenon. This study was conducted to evaluate the clinical implication of iodine and glucose uptake at distant metastatic lesions in DTC patients. PATIENTS, METHODS 64 DTC patients (women 47; mean age 49.9 ± 16.4 years) with distant metastasis who underwent post (131)I treatment whole-body scan (RxWBS) and FDG PET/CT were included in the study. Radioiodine (RAI) and FDG uptake of metastatic lesions were evaluated. TSH stimulated serum thyroglobulin (s-Tg) were obtained. RESULTS 53 of 64 patients (82.8%) were RAI(+) group, and 37 patients (57.8%) were FDG(+) group. Patients in the RAI(-) group showed a higher rate of FDG uptake than RAI(+) group (100.0% vs. 49.1%, p = 0.002). Patients in the FDG(-) group showed a higher rate of RAI uptake than FDG(+) group (100.0% vs. 70.3%, p = 0.002). Patients with s-Tg < 100 ng/ml were frequently observed in the FDG(-)/RAI(+) group and the FDG(+)/RAI(-) group (p = 0.023). And patients with s-Tg ≥ 500 ng/ml were more frequently observed in the FDG(+)/RAI(+) group, compared with the FDG(+)/RAI(-) group (p = 0.036). Reduced disease-specific survival (DSS) was observed in patients with RAI(-) (p = 0.003), FDG(+) (p = 0.006), SUVmax > 3.6 (p<0.001), and s-Tg > 75.8 ng/ml (p = 0.009). In multivariate analysis, only a SUVmax > 3.6 was significantly predictive of DSS (p = 0.006). CONCLUSION An inverse relationship between RAI and FDG uptake, flip-flop phenomenon, was observed in patients with metastatic lesions of DTC. Reduced disease-specific survival was observed in patients with FDG(+), RAI(-) in metastatic lesions, or high s-Tg value.
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Affiliation(s)
- C M Hong
- Department of Nuclear Medicine, Kyungpook National University School of Medicine and Hospital, Daegu, Republic of Korea
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Kim CY, Jeong SY, Lee SW, Park TI, Lee J, Ahn BC. Pathologically proven infective endocarditis demonstrated on ¹⁸F-FDG PET/CT. Rev Esp Med Nucl Imagen Mol 2014; 33:388-9. [PMID: 24636632 DOI: 10.1016/j.remn.2014.01.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 01/08/2014] [Accepted: 01/08/2014] [Indexed: 11/16/2022]
Affiliation(s)
- C-Y Kim
- Department of Nuclear Medicine, Kyungpook National University School of Medicine and Hospital, Daegu, Republic of Korea
| | - S Y Jeong
- Department of Nuclear Medicine, Kyungpook National University School of Medicine and Hospital, Daegu, Republic of Korea
| | - S-W Lee
- Department of Nuclear Medicine, Kyungpook National University School of Medicine and Hospital, Daegu, Republic of Korea
| | - T-I Park
- Department of Pathology, Kyungpook National University School of Medicine and Hospital, Daegu, Republic of Korea
| | - J Lee
- Department of Nuclear Medicine, Kyungpook National University School of Medicine and Hospital, Daegu, Republic of Korea
| | - B-C Ahn
- Department of Nuclear Medicine, Kyungpook National University School of Medicine and Hospital, Daegu, Republic of Korea.
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Cho YC, Kim BS, Yoo H, Kim JY, Lee S, Lee YH, Lee GW, Jeong SY. Successful melting and density measurements of Cu and Ag single crystals with an electrostatic levitation (ESL) system. CrystEngComm 2014. [DOI: 10.1039/c4ce00798k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
By using grain-free single crystal specimens, the melting of Cu and Ag using electrostatic levitation (ESL) and obtaining their high-temperature densities were accomplished for the first time.
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Affiliation(s)
- Yong Chan Cho
- Crystal Bank Institute
- Pusan National University
- Miryang 627-706, Republic of Korea
| | - Bum-Su Kim
- Department of Cogno-Mechatronics Engineering
- Pusan National University
- Miryang 627-706, Republic of Korea
| | - Hanbyeol Yoo
- Korea Research Institute of Standards and Science
- Daejon 305-340, Republic of Korea
| | - Ji Young Kim
- Department of Nano-Fusion Technology
- Pusan National University
- Miryang 627-706, Republic of Korea
| | - Seunghun Lee
- The Institute of Basic Science
- Korea University
- Seoul 136-713, Republic of Korea
| | - Yun-Hee Lee
- Korea Research Institute of Standards and Science
- Daejon 305-340, Republic of Korea
- Department of Science of Measurement
- Korea University of Science and Technology
- Daejon 305-340, Republic of Korea
| | - Geun Woo Lee
- Korea Research Institute of Standards and Science
- Daejon 305-340, Republic of Korea
- Department of Science of Measurement
- Korea University of Science and Technology
- Daejon 305-340, Republic of Korea
| | - Se-Young Jeong
- Crystal Bank Institute
- Pusan National University
- Miryang 627-706, Republic of Korea
- Department of Cogno-Mechatronics Engineering
- Pusan National University
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Lim AR, Kim SH, Jeong SY. 2H and 133Cs nuclear magnetic resonance study of Cs3D(SO4)2 single crystals in laboratory and rotating frames. J Mol Struct 2013. [DOI: 10.1016/j.molstruc.2012.09.082] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Ahn K, Lee HU, Jeong SY, Kim JP, Jin JS, Ahn HS, Kim HS, Cho CR. Plasma treatment effect on dye-sensitized solar cell efficiency of hydrothermal-processed TiO2 nanorods. J Nanosci Nanotechnol 2012; 12:6022-6025. [PMID: 22966701 DOI: 10.1166/jnn.2012.6409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Atmospheric plasma (AP) treatment was carried out on TiO2 nanorods (NRs) that were hydrothermally grown on F-doped SnO2 (FTO)/glass. The effects of AP treatment on the surface of the TiO2 NRs were investigated, where the treatment involved the use of the reactive gases H2, N2, and O2. The surface energy of AP-treated TiO2 NRs was about 1.5 times higher than that of untreated TiO2 NRs (364.3 mJ/m2). After AP treatment, the increase of the peak area ratios of the Ti2O3 and TiO2 peaks in the XPS spectra resulted in a decrease in the number of oxygen vacancies in the TiO2 NRs. The efficiency of a dye-sensitized solar cell (DSSC) based on the N2-plasma-treated TiO2 NRs, which was approximately 1.11%, was about 79% higher than that of a DSSC based on the untreated TiO2 NRs.
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Affiliation(s)
- Kyun Ahn
- College of Nanoscience and Nanotechnology, Pusan National University, Busan 609-735, Korea
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Yun YH, Kim YA, Min YH, Park S, Won YJ, Kim DY, Choi IJ, Kim YW, Park SJ, Kim JH, Lee DH, Yoon SJ, Jeong SY, Noh DY, Heo DS. The influence of hospital volume and surgical treatment delay on long-term survival after cancer surgery. Ann Oncol 2012; 23:2731-2737. [PMID: 22553194 DOI: 10.1093/annonc/mds101] [Citation(s) in RCA: 145] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND We conducted a population-based retrospective cohort study to investigate the influence of hospital volume, delay of surgery, and both together on the long-term survival of postoperative cancer patients. METHODS Using information from the Korea Central Cancer Registry from 2001 through 2005 and the National Health Insurance claim database, we determined survival for 147 682 patients who underwent definitive surgery for any of six cancers. RESULTS Regardless of cancer site, surgical patients in low- to medium-volume hospitals showed significantly worse survival [adjusted hazard ratio (aHR) = 1.36-1.86] than those in high-volume hospitals in multivariable analyses. Among the latter, treatment delays > 1 month were not associated with worse survival for stomach, colon, pancreatic, or lung cancer but were for rectal [aHR = 1.28; 95% confidence interval (CI), 1.17-1.40] and breast (aHR = 1.59; 95% CI, 1.37-1.84) cancer. For patients in low- to medium-volume hospitals, treatment delay was associated with worse survival for all types of cancer (aHR = 1.78-3.81). CONCLUSION Our findings suggest that the effect of hospital volume and surgical treatment delay on overall survival of cancer patients should be considered in formulating or revising national health policy.
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Affiliation(s)
- Y H Yun
- Cancer Research Institute, Seoul National University Hospital and College of Medicine, Seoul
| | - Y A Kim
- Research Institute and Hospital, National Cancer Center, Goyang; Department of Preventive Medicine, Korea University, Seoul
| | - Y H Min
- Research Institute and Hospital, National Cancer Center, Goyang
| | - S Park
- The Korea Central Cancer Registry, Division of Cancer Registration and Surveillance, National Cancer Center, Goyang
| | - Y J Won
- The Korea Central Cancer Registry, Division of Cancer Registration and Surveillance, National Cancer Center, Goyang
| | - D Y Kim
- Research Institute and Hospital, National Cancer Center, Goyang
| | - I J Choi
- Research Institute and Hospital, National Cancer Center, Goyang
| | - Y W Kim
- Research Institute and Hospital, National Cancer Center, Goyang
| | - S J Park
- Research Institute and Hospital, National Cancer Center, Goyang
| | - J H Kim
- Health Insurance Review and Assessment Service, Seoul
| | - D H Lee
- Department of Oncology, Asan Medical Center, Seoul
| | - S J Yoon
- Department of Preventive Medicine, Korea University, Seoul
| | - S Y Jeong
- Department of Surgery, Cancer Research Institute, Seoul
| | - D Y Noh
- Department of Surgery, Cancer Research Institute, Seoul.
| | - D S Heo
- Department of Medicine, Seoul National University College of Medicine, Seoul, Korea
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Cha SY, Shin JM, Kim SJ, Park SE, Cho CR, Cho YC, Jeong SY. Improving the precision of Hall effect measurements using a single-crystal copper probe. Rev Sci Instrum 2012; 83:013901. [PMID: 22299964 DOI: 10.1063/1.3677333] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The circuitry and components of a Hall measurement kit were replaced with single-crystal copper (SCC) wires and parts prepared by a novel wire fabrication process. This process preserved the grain-free structure of SCC grown by the Czochralski method. The new kit was used to determine, with greatly improved precision, the electrical coefficients such as carrier density and mobility, establish the reproducibility of the measured values, and define the semiconductor type. The observed reduction in electrical signal losses and distortion has been attributed to grain boundary elimination.
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Affiliation(s)
- Su-Young Cha
- Department of Nano Fusion Technology, Pusan National University, Miryang, South Korea
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Ajmal M, Lee S, Cho YC, Kim SJ, Park SE, Cho CR, Jeong SY. Fabrication of the best conductor from single-crystal copper and the contribution of grain boundaries to the Debye temperature. CrystEngComm 2012. [DOI: 10.1039/c1ce06026k] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Ahn K, Lee HU, Jeong YM, Kim JP, Jeong SY, Cho CR. Effects of TiO2 nanorod length and post-annealing on the electrical properties of TiO2 nanobarbed fiber structures. J Nanosci Nanotechnol 2011; 11:7155-7158. [PMID: 22103146 DOI: 10.1166/jnn.2011.4847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
TiO2 nanobarbed fiber (NBF) structures consisting of TiO2 nanorods (NRs) on TiO2 nanofibers (NFs) were fabricated. The mean length and diameter of the TiO2 NRs grown for 6 h was 1.38 microm and 71 nm, respectively. One NR was connected to other NRs and the junction points between the TiO2 NRs increased with increasing TiO2 NR length. The crystal structure of the TiO2 NFs and NRs was rutile and anatase, respectively. After post-annealing, only the intensity of the TiO2 NBF peaks increased without any significant structural changes. Raman spectroscopy showed that the TiO2 NBF structure consisted of anatase (TiO2 NFs) and rutile (TiO2 NRs). The bandgap of the TiO2 NBF structure prepared during a TiO2 NR growth time from 0 to 6 h decreased from 3.23 eV to 3.10 eV. The conductivity of the TiO2 NBFs with longer NRs was enhanced by post-annealing.
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Affiliation(s)
- Kyun Ahn
- College of Nanoscience and Nanotechnology, Pusan National University, Busan 609735, Korea
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Lee HU, Park SY, Kang YH, Jeong SY, Choi SH, Jahng YY, Chung GH, Kim MB, Cho CR. Improved cell viability of biocompatible nutrient-contained polymeric nanofibers. J Nanosci Nanotechnol 2011; 11:7100-7103. [PMID: 22103133 DOI: 10.1166/jnn.2011.4867] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Nanofibers containing cell nutrients (PGDs) were fabricated by mixing 5 wt% poly(epsilon-caprolactone) (P), 4 wt% gelatin (G), and 0-2.4 wt% Dulbecco's Modified Eagle's Medium (D). The contact angles showed a considerable decrease from 118.4 degrees on the P scaffold to 17.6 degrees on PGD1.6 (containing 1.6 wt% D). The weight loss ratios between PGD1.6 and the P nanofiber, and between PGD1.6 and the PG nanofiber by degradation after 28 days were approximately 3.1 and 1.4, respectively. The rate of cell proliferation on PGD1.6 was greater than that on the PG nanofiber by 14% and 38% for the exchanged and unexchanged culture media, respectively. The physicochemical measurement results showed that the PGDs exhibited enhanced hydrophilic properties and rapid biodegradation. The PGD nanofibers with increasing D content showed better conditions for long-term cell viability. The growth mechanism of the cells on the PGDs was explained by an attachment and growth process.
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Affiliation(s)
- Hyun-Uk Lee
- College of Nanoscience and Nanotechnology, Pusan National University, Busan 609-735, Korea
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Park JK, Jeong SY, Lee JH, Lim GC, Chang JW. Variations in the course of the cervical vagus nerve on thyroid ultrasonography. AJNR Am J Neuroradiol 2011; 32:1178-81. [PMID: 21757523 DOI: 10.3174/ajnr.a2476] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Only 1 ultrasonography study that described the variation of the VN had been published at the time our research was begun. The purpose of this study was to evaluate the incidence and type of variation in the course of the cervical VN on thyroid ultrasonography. MATERIALS AND METHODS From August 2009 to September 2010, 163 consecutive patients were evaluated by sonography for the screening and characterization of thyroid nodules (mean age, 49.0 ± 14.4 years, male:female, 20:143). Two types of variation were defined as follows: 1) anterior variation, when the course of the VNs changed from the typical location to an anterior location in front of the CCA; and 2) medial variation, when the course of the VNs changed from the typical location to a location medial to the CCA (between CCA and thyroid gland). The incidence of the each variation was studied. RESULTS Variation in the course of the VN occurred in 5.5% (18/326) of cases. The anterior variation was observed in 4.3% (14/326, right:left = 4:10), and the medial variation was observed in 1.2% (4/326, right:left = 3:1). For both variations, the VN was close to or nearly abutted the thyroid gland after it changed course. CONCLUSIONS Variation in the course of the cervical VN could be assessed by ultrasonography. Two variations were observed in 5.5% of cases. The anterior variation was more common than the medial variation.
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Affiliation(s)
- J K Park
- Departments of Radiology,Jeju National University College of Medicine, Jeju, Korea
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Kwak YG, Lee SO, Kim HY, Kim YK, Park ES, Jin HY, Choi HJ, Jeong SY, Kim ES, Ki HK, Kim SR, Lee JY, Hong HK, Kim S, Lee YS, Oh HB, Kim JM. Risk factors for device-associated infection related to organisational characteristics of intensive care units: findings from the Korean Nosocomial Infections Surveillance System. J Hosp Infect 2010; 75:195-9. [PMID: 20434798 DOI: 10.1016/j.jhin.2010.01.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2009] [Accepted: 01/13/2010] [Indexed: 10/19/2022]
Abstract
Device-associated infections (DAIs) have been the major causes of morbidity and mortality of patients in intensive care units (ICUs). This study evaluated the risk factors for DAIs in ICUs. Ninety-six medical or surgical ICUs of 56 hospitals participated in the Korean Nosocomial Infections Surveillance System between July 2007 and June 2008. The occurrence of catheter-associated urinary tract infection (CAUTI), central line-associated bloodstream infection (CABSI), and ventilator-associated pneumonia (VAP) were monitored and DAI rates were calculated. Data associated with ICU characteristics were collected and Poisson regression was used for statistical analysis. Rates of CAUTI, CABSI, and VAP were 3.87 per 1000 urinary catheter days, 2.23 per 1000 central line days, and 1.89 per 1000 mechanical ventilator days, respectively. Rates of CAUTI were higher in ICUs in Seoul (P=0.032) and ICUs of major teaching hospitals (P=0.010). The ICUs of university-affiliated hospitals showed lower CAUTI rates (P=0.013). CABSI rates were higher in Seoul (P=0.001) and in medical ICUs (P=0.026). VAP rates were lower in ICUs of hospitals with more than 900 beds compared with hospitals with 400-699 beds (P=0.026). VAP rates were higher in surgical ICUs (P<0.0001) and increased 1.13-fold with each 100-unit increase in beds per infection control professional (P=0.003). The organisational and institutional characteristics of ICUs may influence DAI rates and there is a need for improvement in the incidence of VAP, CAUTI or CABSI.
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Affiliation(s)
- Y G Kwak
- Department of Infectious Diseases, Inje University Ilsan Paik Hospital, Goyang, Republic of Korea
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Lee HU, Park SY, Kang YH, Jeong SY, Choi SH, Jahng KY, Cho CR. Surface modification of and selective protein attachment to a flexible microarray pattern using atmospheric plasma with a reactive gas. Acta Biomater 2010; 6:519-25. [PMID: 19607941 DOI: 10.1016/j.actbio.2009.07.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2008] [Revised: 05/19/2009] [Accepted: 07/09/2009] [Indexed: 11/25/2022]
Abstract
The hydrophobic and hydrophilic properties of the surface of poly-ether sulfone (PES) films were controlled by an atmospheric pressure plasma (AP) treatment using reactive gases (Ar/H(2) and Ar/O(2)). The surface properties of the Ar/H(2) and Ar/O(2) in series AP-treated PES films showed higher surface roughness (approximately 120%), surface energy (approximately 30%) and hydrophilic properties (oxygen content approximately 10%) than the Ar/O(2) AP-treated PES film. The protein staining results confirmed that an activated region on the patterned PES film with high selectivity and sensitivity was well-defined and formed. This method is suitable for fabricating flexible protein adhesive chips with uniform biomolecular adhesive properties.
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Lim SB, Jeong SY, Choi HS, Sohn DK, Hong CW, Jung KH, Chang HJ, Park JG, Choi IJ, Kim CG. Synchronous gastric cancer in primary sporadic colorectal cancer patients in Korea. Int J Colorectal Dis 2008; 23:61-5. [PMID: 17724601 DOI: 10.1007/s00384-007-0366-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/26/2007] [Indexed: 02/08/2023]
Abstract
BACKGROUND AND AIMS Colorectal cancer has been reported to be the malignancy most frequently associated with gastric cancer in Korea. The aim of this study was to define the frequency and clinical characteristics of synchronous gastric cancer detected at preoperative esophagogastroduodenoscopy (EGD) in colorectal cancer patients. MATERIALS AND METHODS This prospective study analyzed the EGD results from 1,542 consecutive colorectal cancer patients who underwent surgery from January 2003 to December 2005 at the Center for Colorectal Cancer, National Cancer Center, Korea. RESULTS Of the 1,542 cases, 1,155 (74.9%) underwent EGD at our center and 387 underwent EGD at other hospitals within 6 months before surgery. Of the 1,542 cases, synchronous gastric cancers were detected in 31 cases (2.0%). Of these 31 cases, 26 had early gastric cancer (EGC; 83.9%) and 5 had advanced gastric cancer. Ten (38.5%) of the 26 EGC cases were managed using endoscopic mucosal resection. Compared to colorectal cancer patients without synchronous gastric cancer, the group of patients with synchronous gastric cancer was older (65.5+/-9.6 vs 58.4+/-11.3 years, p=0.001) and had a greater proportion of males (77.4 vs 59.4%, p=0.043). CONCLUSION This study found that 2% of Korean sporadic colorectal cancer patients had synchronous gastric cancer. A preoperative EGD for colorectal cancer patients is likely to greatly assist in the diagnosis of synchronous gastric cancer at an early stage and the implementation of appropriate minimally invasive treatment.
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Affiliation(s)
- S B Lim
- Center for Colorectal Cancer, Research Institute and Hospital, National Cancer Center, Goyang-si, Korea
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Futai E, Sorimachi H, Jeong SY, Kitamoto K, Ishiura S, Suzuki K. Aspergillus oryzae palBory encodes a calpain-like protease: homology to Emericella nidulans PalB and conservation of functional regions. J Biosci Bioeng 2005; 88:438-40. [PMID: 16232641 DOI: 10.1016/s1389-1723(99)80223-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/1999] [Accepted: 07/09/1999] [Indexed: 11/17/2022]
Abstract
We have cloned and sequenced genomic DNA of Aspergillus oryzae palBory, orthologue of Emericella nidulans palB, which encodes a calpain-like protease modulating a signal transduction pathway during alkaline adaptation. The deduced amino acid sequence of PalBory is 70.0% identical to PalB over its entire length. The regions with high similarity revealed possible domains important for their function. This is the first step towards understanding the alkaline adaptation mechanism of A. oryzae, which would be very useful in the fermentation industry.
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Affiliation(s)
- E Futai
- Department of Molecular Biology, Institute of Molecular and Cellular Biosciences, University of Tokyo, Tokyo 113-0032, Japan
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Lim AR, Jeong SY. A study of the NMR relaxation mechanisms of ABCl3 (A=Rb, Cs, B=Cd, Mn) single crystals with the electric quadrupole and the electric magnetic types. J SOLID STATE CHEM 2005. [DOI: 10.1016/j.jssc.2005.07.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Abstract
AIM To determine the effect of polyurethane film with sustained release dexamethasone (SRD) in delayed adjustable strabismus surgery. METHODS A prospective, masked observer, controlled study was performed in rabbits. Thirty four rabbit eyes were divided into three groups. After recession of the superior rectus muscle (SRM), polyurethane film with or without SRD, or balanced salt solution was applied beneath and over SRM in the polyurethane-dexamethasone group (group P-D), polyurethane group (group P), and the control group (group C), respectively. Delayed adjustment was performed once on each SRM at 4 and 6 weeks postoperatively by a masked observer. The possible length to adjust and the necessary force required for the adjustment, as well as the degree of any adhesions, were also evaluated. RESULTS In the control group, adjustment was impossible in all of the eyes at 4 and 6 weeks postoperatively. In group P-D, adjustment was possible in 11 out of 11 eyes (11/11) 4 weeks postoperatively and in 10/11 eyes 6 weeks postoperatively. In group P, adjustment was possible in 9/11 eyes 4 weeks postoperatively and in 10/12 eyes 6 weeks postoperatively. CONCLUSIONS Use of polyurethane film with and without SRD could delay adjustment in most eyes for up to 6 weeks postoperatively. Polyurethane is helpful for delaying adjustment in rabbit eyes until 6 weeks postoperatively without the need for frequent topical instillation of steroids.
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Affiliation(s)
- J H Kim
- Department of Ophthalmology, College of Medicine Seoul National University, Seoul National University Bundang Hospital, Seongnam, Korea
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