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Choi J, Park J, Park J, Kim M, Lee S, Cho CR, Lee JH, Park Y, Kim MG, Choi J, Park JW, Park M. Low-Index Facet Polyhedron-Shaped Binary Cerium Titanium Oxide for High-Voltage Aqueous Zinc-Vanadium Redox Flow Batteries. ACS Appl Mater Interfaces 2023; 15:55692-55702. [PMID: 37981729 DOI: 10.1021/acsami.3c11734] [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] [Subscribe] [Scholar Register] [Indexed: 11/21/2023]
Abstract
Aqueous zinc-vanadium hybrid redox flow battery systems are an efficient strategy to address the problems of low voltage and high cost of conventional all-vanadium redox flow batteries. However, the low electrochemical activity of carbon-based electrodes toward a vanadium redox reaction limits the performance of redox flow batteries. In this study, polyhedral binary cerium titanium oxide (Ce2/3TiO3, CTO) is synthesized using molten salt synthesis. CTO is fabricated by adjusting the temperature and composition. Notably, the prepared CTO obtained at 1000 °C shows the highest catalytic activity for a VO2+/VO2+ redox reaction. Further, CTO is prepared as a composite electrocatalyst and applied to a high-voltage aqueous zinc-vanadium redox flow battery. The cell adopts an alkali zinc electrolyte containing a Zn/[Zn(OH)4]2- redox pair and exhibits a high operating voltage of 2.26 V. Remarkably, a zinc-vanadium redox flow battery using the composite electrocatalyst exhibits a high energy density of 42.68 Wh L-1 at 20 mA cm-2 and an initial voltage efficiency of 90.3%. The excellent cell performance is attributed to structural defects caused by A-site deficiency in the perovskite oxide structure as well as oxygen vacancies resulting from the low valence state of the metal ion, which enhance the catalytic activity of the vanadium ions.
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Affiliation(s)
- Jinyeong Choi
- Department of Nanoenergy Engineering, Pusan National University, 50, Busandaehak-ro 63 beon-gil 2, Geumjeong-gu, Busan 46241, Republic of Korea
- Research Center of Energy Convergence Technology, Pusan National University, Busandaehak-ro 63 beon-gil 2, Geumjeong-gu, Busan 46241, Republic of Korea
- Department of Nano Fusion Technology, Pusan National University, Busandaehak-ro 63 beon-gil 2, Geumjeong-gu, Busan 46241, Republic of Korea
| | - Joohyuk Park
- Department of Advanced Materials Engineering, Keimyung University, 1095 Dalgubeol-daero, Dalseo-gu, Daegu 42601, Republic of Korea
| | - Jihan Park
- Department of Nanoenergy Engineering, Pusan National University, 50, Busandaehak-ro 63 beon-gil 2, Geumjeong-gu, Busan 46241, Republic of Korea
- Research Center of Energy Convergence Technology, Pusan National University, Busandaehak-ro 63 beon-gil 2, Geumjeong-gu, Busan 46241, Republic of Korea
- Department of Nano Fusion Technology, Pusan National University, Busandaehak-ro 63 beon-gil 2, Geumjeong-gu, Busan 46241, Republic of Korea
| | - Minsoo Kim
- Department of Nanoenergy Engineering, Pusan National University, 50, Busandaehak-ro 63 beon-gil 2, Geumjeong-gu, Busan 46241, Republic of Korea
- Research Center of Energy Convergence Technology, Pusan National University, Busandaehak-ro 63 beon-gil 2, Geumjeong-gu, Busan 46241, Republic of Korea
- Department of Nano Fusion Technology, Pusan National University, Busandaehak-ro 63 beon-gil 2, Geumjeong-gu, Busan 46241, Republic of Korea
| | - Soobeom Lee
- Department of Nanoenergy Engineering, Pusan National University, 50, Busandaehak-ro 63 beon-gil 2, Geumjeong-gu, Busan 46241, Republic of Korea
- Research Center of Energy Convergence Technology, Pusan National University, Busandaehak-ro 63 beon-gil 2, Geumjeong-gu, Busan 46241, Republic of Korea
- Department of Nano Fusion Technology, Pusan National University, Busandaehak-ro 63 beon-gil 2, Geumjeong-gu, Busan 46241, Republic of Korea
| | - Chae Ryong Cho
- Department of Nanoenergy Engineering, Pusan National University, 50, Busandaehak-ro 63 beon-gil 2, Geumjeong-gu, Busan 46241, Republic of Korea
- Department of Nano Fusion Technology, Pusan National University, Busandaehak-ro 63 beon-gil 2, Geumjeong-gu, Busan 46241, Republic of Korea
| | - Jin Hong Lee
- School of Chemical Engineering, Pusan National University, Gumjeong-ku 46241, Republic of Korea
| | - Yiseul Park
- Department of Chemical Engineering, Pukyong National University, Busan 48513, Republic of Korea
| | - Min Gyu Kim
- PLS-II Beamline Division, PLS-II Department, Pohang Accelerator Laboratory (PAL), Pohang University of Science and Technology (POSTECH), Pohang, Gyeongbuk 37673, Republic of Korea
| | - Jaewon Choi
- Department of Polymer Science and Engineering, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Jun-Woo Park
- Next Generation Battery Research Center, Korea Electrotechnology Research Institute (KERI), Changwon,Gyeongsangnam-do 51543, Republic of Korea
- Department of Electro-Functionality Materials Engineering, University of Science and Technology (UST), Daejeon 34113, Republic of Korea
| | - Minjoon Park
- Department of Nanoenergy Engineering, Pusan National University, 50, Busandaehak-ro 63 beon-gil 2, Geumjeong-gu, Busan 46241, Republic of Korea
- Research Center of Energy Convergence Technology, Pusan National University, Busandaehak-ro 63 beon-gil 2, Geumjeong-gu, Busan 46241, Republic of Korea
- Department of Nano Fusion Technology, Pusan National University, Busandaehak-ro 63 beon-gil 2, Geumjeong-gu, 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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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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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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Gao Y, Yin L, Kim SJ, Yang H, Jeon I, Kim JP, Jeong SY, Lee HW, Cho CR. Enhanced lithium storage by ZnFe2O4 nanofibers as anode materials for lithium-ion battery. Electrochim Acta 2019. [DOI: 10.1016/j.electacta.2018.11.093] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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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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Song JE, Kwak YG, Um TH, Cho CR, Kim S, Park IS, Hwang JH, Kim N, Oh GB. Outbreak of Burkholderia cepacia pseudobacteraemia caused by intrinsically contaminated commercial 0.5% chlorhexidine solution in neonatal intensive care units. J Hosp Infect 2017; 98:295-299. [PMID: 28935523 DOI: 10.1016/j.jhin.2017.09.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [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: 06/27/2017] [Accepted: 09/13/2017] [Indexed: 12/20/2022]
Abstract
BACKGROUND Burkholderia cepacia is intrinsically resistant to certain antiseptics. The authors noted a sudden increase in the frequency of isolation of B. cepacia from blood cultures in a neonatal intensive care unit (NICU) of a university-affiliated hospital. AIM To identify the source and intervene in the ongoing infections. METHODS The cases were defined as patients with positive blood cultures for B. cepacia in an NICU between November 2014 and January 2015. Medical records were reviewed and NICU healthcare workers were interviewed. Samples of suspected antiseptics, blood culture bottles, cotton balls, gauze and a needle used in the NICU were analysed microbiologically. FINDINGS During the outbreak period, B. cepacia was identified in 25 blood cultures obtained from 21 patients. The clinical features of the patients were suggestive of pseudobacteraemia. Regarding environmental samples, B. cepacia was cultured from 0.5% chlorhexidine gluconate (CHG) solution products that had been used as a skin antiseptic during blood drawing in the NICU. The clinical B. cepacia isolate and two strains obtained from 0.5% CHG exhibited identical pulsed-field gel electrophoresis patterns. After the CHG products were withdrawn, the outbreak was resolved. CONCLUSIONS The pseudobacteraemia cases were caused by contaminated 0.5% CHG produced by a single manufacturer. Stricter government regulation is needed to prevent contamination of disinfectants during manufacturing. In addition, microbial contamination of antiseptics and disinfectants should be suspected when a B. cepacia outbreak occurs in hospitalized patients.
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Affiliation(s)
- J E Song
- Department of Internal Medicine, Inje University Ilsan Paik Hospital, Goyang, Republic of Korea; Infection Control Office, Inje University Ilsan Paik Hospital, Goyang, Republic of Korea; Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Y G Kwak
- Department of Internal Medicine, Inje University Ilsan Paik Hospital, Goyang, Republic of Korea; Infection Control Office, Inje University Ilsan Paik Hospital, Goyang, Republic of Korea.
| | - T H Um
- Department of Laboratory Medicine, Inje University Ilsan Paik Hospital, Goyang, Republic of Korea
| | - C R Cho
- Department of Laboratory Medicine, Inje University Ilsan Paik Hospital, Goyang, Republic of Korea; Infection Control Office, Inje University Ilsan Paik Hospital, Goyang, Republic of Korea
| | - S Kim
- Department of Laboratory Medicine, Inje University Ilsan Paik Hospital, Goyang, Republic of Korea
| | - I S Park
- Department of Laboratory Medicine, Inje University Ilsan Paik Hospital, Goyang, Republic of Korea
| | - J H Hwang
- Department of Paediatrics, Inje University Ilsan Paik Hospital, Goyang, Republic of Korea
| | - N Kim
- Department of Paediatrics, Inje University Ilsan Paik Hospital, Goyang, Republic of Korea; Infection Control Office, Inje University Ilsan Paik Hospital, Goyang, Republic of Korea
| | - G-B Oh
- Infection Control Office, Inje University Ilsan Paik 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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Pham-Cong D, Choi JH, Yun J, Bandarenka AS, Kim J, Braun PV, Jeong SY, Cho CR. Synergistically Enhanced Electrochemical Performance of Hierarchical MoS 2/TiNb 2O 7 Hetero-nanostructures as Anode Materials for Li-Ion Batteries. ACS Nano 2017; 11:1026-1033. [PMID: 28040886 DOI: 10.1021/acsnano.6b07666] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
As potential high-performance anodes for Li-ion batteries (LIBs), hierarchical heteronanostructures consisting of TiNb2O7 nanofibers and ultrathin MoS2 nanosheets (TNO@MS HRs) were synthesized by simple electrospinning/hydrothermal processes. With their growth mechanism revealed, the TNO@MS HRs exhibited an entangled structure both for their ionic and electronic conducting pathways, which enabled the synergetic combination of one- and two-dimensional structures to be realized. In the potential range of 0.001-3 V vs Li/Li+, the TNO@MS HR-based LIBs exhibited high capacities of 872 and 740 mAh g-1 after 42 and 200 cycles at a current density of 1 A g-1, respectively, and excellent rate performance of 611 mAh g-1 at 4 A g-1. We believe that the fabrication route of TNO@MS HRs will find visibility for the use of anode electrodes for high capacity LIBs at low cost.
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Affiliation(s)
- De Pham-Cong
- Department of Nanoenergy Engineering and College of Nanoscience and Nanotechnology, Pusan National University , Busan 46241, Republic of Korea
| | - Jun Hee Choi
- Device & System Research Center, Samsung Advanced Institute of Technology, Samsung Electronics , Suwon 16676, Republic of Korea
| | - Jeongsik Yun
- Physik-Department ECS, Technische Universität München , James-Franck-Straße 1, 85748 Garching, Germany
| | - Aliaksandr S Bandarenka
- Physik-Department ECS, Technische Universität München , James-Franck-Straße 1, 85748 Garching, Germany
| | - Jinwoo Kim
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States
| | - Paul V Braun
- Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States
| | - Se Young Jeong
- Department of Nanoenergy Engineering and College of Nanoscience and Nanotechnology, Pusan National University , Busan 46241, Republic of Korea
| | - Chae Ryong Cho
- Department of Nanoenergy Engineering and College of Nanoscience and Nanotechnology, Pusan National University , Busan 46241, Republic of Korea
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Kim J, Kim JY, Pham-Cong D, Jeong SY, Chang J, Choi JH, Braun PV, Cho CR. Individually carbon-coated and electrostatic-force-derived graphene-oxide-wrapped lithium titanium oxide nanofibers as anode material for lithium-ion batteries. Electrochim Acta 2016. [DOI: 10.1016/j.electacta.2016.03.137] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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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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12
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Liu GX, Liu A, Meng Y, Shan FK, Shin BC, Lee WJ, Cho CR. Annealing Dependence of Solution-Processed Ultra-Thin ZrOx Films for Gate Dielectric Applications. J Nanosci Nanotechnol 2015; 15:2185-2191. [PMID: 26413638 DOI: 10.1166/jnn.2015.10228] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Ultra-thin ZrOx thin films on Si substrates were prepared by sol-gel technique and processed with different methods (baked on hot plate at 150 °C, annealed at 500 °C in furnace, and photo-annealed under UV light). The decomposition of the organic groups and the formation of Zr-O bonding in the ZrOx thin films were confirmed by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. It is found that the ZrOx thin film annealed under UV light shows decent characteristics, including an ultra-small surface roughness, a low leakage current density of 10(-9) A/cm2 at 1 MV/cm, a large breakdown electric field of 9.5 MV/cm, and a large areal capacitance of 775 nF/cm2.
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13
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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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14
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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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15
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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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16
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Jang JS, Borse PH, Lee JS, Lim KT, Cho CR, Jeong ED, Ha MG, Won MS, Kim HG. Photocatalytic performance of nanocrystalline Bi5Ti3FeO15 layered perovskite under visible light. J Nanosci Nanotechnol 2010; 10:5008-5014. [PMID: 21125843 DOI: 10.1166/jnn.2010.2221] [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] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Nanocrystalline Bi5Ti3FeO15 layered perovskite exhibiting Aurivillius phase was synthesized by polymerized complex (PC) method and investigated for its physico-chemical as well as optical properties. The crystallization of Bi5Ti3FeO15 synthesized by PC method was found to occur in the temperature range of 800-1050 degress C, whereas the single crystalline Bi5Ti3FeO15 formed at 1030 degrees C by solid state reaction (SSR) method. The observation of highly pure phase and such lower crystallization temperature in Bi5Ti3FeO15 prepared by PC method, is in total contrast to that observed in Bi5Ti3FeO15 prepared by the conventional solid-state reaction (SSR) method. The band gap of nanocrystalline Bi5Ti3FeO15 determined from UV-Vis diffusion reflectance spectrometer was 2.38 eV (525 nm). The photocatalytic activity of Pt/Bi5Ti3FeO15 prepared by PC method was investigated with the photodecomposition of isopropyl alcohol (IPA) and hydrogen production from water-methanol mixed solution under visible light (lambda > or = 420 nm). The respective activities for PC sample were higher than that of Pt/Bi5Ti3FeO15 prepared by SSR as well as Pt/TiO(2-x)N(x).
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Affiliation(s)
- Jum Suk Jang
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang 790-784, Korea
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Jeong ED, Borse PH, Jang JS, Lee JS, Cho CR, Bae JS, Park S, Jung OS, Ryu SM, Won MS, Kim HG. Physical and optical properties of nanocrystalline calcium ferrite synthesized by the polymerized complex method. J Nanosci Nanotechnol 2009; 9:3568-3573. [PMID: 19504883 DOI: 10.1166/jnn.2009.ns31] [Citation(s) in RCA: 5] [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: 05/27/2023]
Abstract
Nanocrystalline CaFe2O4 oxide semiconductor with spinel structure was synthesized by polymerized complex (PC) method and investigated for its physical and optical properties. The crystallization of CaFe2O4 made by PC method was found to occur in the temperature range of 700-1100 degrees C. The observation of highly pure phase and such lower crystallization tempearture in CaFe2O4 made by PC method, is in total contrast to that observed in CaFe2O4 prepared by the conventional solid-state reaction (SSR) method. The activation energy required for the growth of nanocrystalline CaFe2O4 in PC sample was found to be 8.4 kJ/mol. The band gap of nanocrystalline CaFe2O4 determined by UV-DRS was 1.91 eV (647 nm). The photocatalytic activity of PC materials for iso-propyl alcohol photodegradation under visible light (> or =420 nm) was much higher than that of SSR materials.
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Affiliation(s)
- Euh Duck Jeong
- Busan Center, Korea Basic Science Institute, Busan 609-735, Korea
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Chung DI, Kong HH, Yu HS, Kim J, Cho CR. Live female Enterobius vermicularis in the posterior fornix of the vagina of a Korean woman. Korean J Parasitol 1997; 35:67-9. [PMID: 9100442 DOI: 10.3347/kjp.1997.35.1.67] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A 33-year-old Korean woman, para 2. visited an obstetrics and gynecology clinic, Kumi-shi, Kyongsangbuk-do, due to postcoital spotting and flank pain. She had a tubal ligation 7 years before and demonstrated back pain during menstruation. She revealed a foul smelling discharge without complaint of itching. Enterobius vermicularis eggs were demonstrated during microscopic examination of a smear taken from the posterior fornix of the vagina. On endoscopic examination of her vagina, a live worm was found in the posterior fornix. The worm was removed and identified as a female E. vermicularis based on morphology. This is the first case report of vaginal enterobiasis in Korea.
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Affiliation(s)
- D I Chung
- Department of Parasitology, Kyungpook National University School of Medicine, Korea
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Abstract
Intussusception associated with Yersinia pseudotuberculosis infection was developed in three boys; two of them had a history of drinking untreated water. All intussusceptions were localized at the ileocolic region, and all patients completely recovered with Gastrografin enema and supportive treatment without complication and operation.
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Affiliation(s)
- J W Koo
- Department of Pediatrics, College of Medicine, Inje University, Sanggye Paik Hospital, Seoul, Korea
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20
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Abstract
We report 45 pediatric cases of Yersinia pseudotuberculosis infection confirmed by stool culture between May 1993 and June 1994. In 41 (91.1%) cases there had been contact with untreated well or mountain water. Y. pseudotuberculosis was also isolated from 4 samples of mountain spring water thought to be the sources of infection. During the course of the illness, acute renal failure (ARF) developed in 6 patients (13.6%). The age distribution of the ARF group (12.3 +/- 1.2 years) was significantly different from the non-ARF group (8.0 +/- 3.2 years). The serogroups of Y. pseudotuberculosis isolates from stool samples were 5 (n = 30) and 4 (n = 15). Isolates from the water samples were all serogroup 5. The main symptoms of both groups were fever, rash, abdominal pain, and vomiting. ARF developed between the 2nd and 14th days (mean 6 days) after the onset of fever, and oliguria (< 400 ml/m2 per day) developed in 3 patients (3/6, 50%) immediately after their fevers had subsided. ARF underwent a benign course, with complete recovery within a maximum of 4 weeks (mean 10.2 days), with 1 exceptional patient requiring hemodialysis. Renal biopsy showed evidence of tubulointerstitial nephritis. Y. pseudotuberculosis should be included as one of the causes of acute interstitial nephritis causing ARF in children, especially when the children have histories of drinking untreated water in endemic areas.
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Affiliation(s)
- J W Koo
- Department of Pediatrics, College of Medicine, Inje University, Sanggye Paik Hospital, Seoul, Korea
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Abstract
Detachment of epithelial cells from the glomerular capillary wall correlates with the massive increase in protein leakage across the capillary wall that is characteristic of many renal diseases. We introduce the hypothesis that this detachment process involves three classes of physical events acting at the subcellular level: the receptor-mediated binding of epithelial cells to basement membrane, the transglomerular hydraulic pressure gradient acting to lift the cells off the basement membrane, and a receptor-receptor co-operativity induced by mechanical deformations of the epithelial cell surface. After presenting the available evidence, we explore the hypothesis by means of a simplified, quantitative model of the detachment process. The model is developed by mapping between the stochastic events of cell adhesion receptor binding and the equilibrium statistical mechanics of the Ising model. Monte Carlo simulations predict cell attachment under normal conditions, as expected from experimental data, and detachment at lower receptor binding affinity and/or increased pressure gradient. The normal attached state in the model is found to be particularly sensitive to changes in the receptor-binding affinity. The amount of resistance the cell surface offers to deformation forces is a key determinant of whether the detachment of small clusters of receptors spreads to involve large areas of the plasma membrane, precipitating bulk detachment.
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Affiliation(s)
- C R Cho
- Membrane Biology Group, University of Toronto, Ontario, Canada
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Cho CR, Winslow J, Whiteside C, Lumsden CJ. A new computer-assisted three-dimensional reconstruction method provides accurate measurement of glomerular mesangial volume. J Electron Microsc Tech 1991; 18:249-61. [PMID: 1880598 DOI: 10.1002/jemt.1060180307] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Many glomerulopathies are characterized by progressive mesangial (interstitial) expansion which can be quantitated by morphometric analysis. The purpose of this study was to analyze mesangial and glomerular volumes using a new computer-assisted reconstruction (CAR) method. CAR was compared to two standard planar methods, point-counting and linear integration, for accuracy and time efficiency. In Phase I of the study, a computer-based model of the mesangial space was created by placing spherical and ellipsoidal objects of known volume into an enclosing volume mimicking the glomerulus. The simulated mesangium occupied approximately 10 percent of the glomerular volume. The model glomerulus was sectioned serially into ten sections of equal thickness and the three morphometric methods applied to determine the mesangial/glomerular volume. The complexity of the mesangial model was varied by increasing the number of mesangial regions from one to ten to 100. The CAR method estimated the model mesangial volume more accurately (1-9 percent error) through each level of complexity compared to point-counting (3-17 percent error) and linear integration (3-18 percent error). The point-counting method consistently overestimated (P less than 0.05) the fractional mesangial volume for the ten- and 100-region mesangium models. In Phase II of the study, a normal rat glomerulus was sectioned serially (215 sections) and a transmission electron micrograph (TEM) of every fifth section (n = 43) was obtained. Each TEM image (2% of glomerular surface) was digitized for analysis by CAR. Point-counting and linear integration were also performed on the whole glomerular TEMs (n = 10, randomly chosen). The estimated relative mesangial/glomerular volume was 6.6 +/- 0.1 percent by CAR (mean +/- SD), 9.7 +/- 1.5 by linear integration, and 14.9 +/- 3.4 by point-counting. The point-counting method was most efficient, requiring 40 +/- 8 sec/section, followed by CAR at 85 +/- 24 sec/section. Linear integration was least efficient (93 +/- 23 sec/section). We conclude that CAR is the most accurate morphometric method of the three compared for estimating mesangial and glomerular methods, although it is more time consuming than the point-counting method and requires more complex instrumentation. CAR is the only method that will analyze the shape and three-dimensional complexity of glomerular structures using TEMs.
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Affiliation(s)
- C R Cho
- Department of Medicine, University of Toronto, Ontario, Canada
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