1
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Nguyen HS, Kang SJ, Kim S, Cha BH, Park KS, Jeong SW. Changes in the expression of satellite glial cell-specific markers during postnatal development of rat sympathetic ganglia. Brain Res 2024; 1829:148809. [PMID: 38354998 DOI: 10.1016/j.brainres.2024.148809] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 01/31/2024] [Accepted: 02/08/2024] [Indexed: 02/16/2024]
Abstract
The sympathetic ganglia represent a final motor pathway that mediates homeostatic "fight and flight" responses in the visceral organs. Satellite glial cells (SGCs) form a thin envelope close to the neuronal cell body and synapses in the sympathetic ganglia. This unique morphological feature suggests that neurons and SGCs form functional units for regulation of sympathetic output. In the present study, we addressed whether SGC-specific markers undergo age-dependent changes in the postnatal development of rat sympathetic ganglia. We found that fatty acid-binding protein 7 (FABP7) is an early SGC marker, whereas the S100B calcium-binding protein, inwardly rectifying potassium channel, Kir4.1 and small conductance calcium-activated potassium channel, SK3 are late SGC markers in the postnatal development of sympathetic ganglia. Unlike in sensory ganglia, FABP7 + SGC was barely detectable in adult sympathetic ganglia. The expression of connexin 43, a gap junction channel gradually increased with age, although it was detected in both SGCs and neurons in sympathetic ganglia. Glutamine synthetase was expressed in sensory, but not sympathetic SGCs. Unexpectedly, the sympathetic SGCs expressed a water-selective channel, aquaporin 1 instead of aquaporin 4, a pan-glial marker. However, aquaporin 1 was not detected in the SGCs encircling large neurons. Nerve injury and inflammation induced the upregulation of glial fibrillary acidic protein, suggesting that this protein is a hall marker of glial activation in the sympathetic ganglia. In conclusion, our findings provide basic information on the in vivo profiles of specific markers for identifying sympathetic SGCs at different stages of postnatal development in both healthy and diseased states.
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Affiliation(s)
- Huu Son Nguyen
- Department of Physiology, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea; Mitohormesis Research Center, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
| | - Seong Jun Kang
- Department of Physiology, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
| | - Sohyun Kim
- Department of Physiology, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
| | - Byung Ho Cha
- Department of Pediatrics, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
| | - Kyu-Sang Park
- Department of Physiology, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea; Mitohormesis Research Center, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea
| | - Seong-Woo Jeong
- Department of Physiology, Yonsei University Wonju College of Medicine, Wonju, Republic of Korea.
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2
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Kim YB, Jeong JH, Park MH, Yun JM, Ma JH, Ha HJ, Kang SJ, Kang SJ. Low-Power Phototransistor with Enhanced Visible-Light Photoresponse and Electrical Performances Using an IGZO/IZO Heterostructure. Materials (Basel) 2024; 17:677. [PMID: 38591507 PMCID: PMC10856061 DOI: 10.3390/ma17030677] [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: 01/02/2024] [Revised: 01/24/2024] [Accepted: 01/29/2024] [Indexed: 04/10/2024]
Abstract
In this study, we demonstrated the effective separation of charge carriers within the IGZO/IZO heterostructure by incorporating IZO. We have chosen IGZO for its high mobility and excellent on-off switching behavior in the front channel of our oxide-oxide heterostructure. Similarly, for an additional oxide layer, we have selected IZO due to its outstanding electrical properties. The optimized optoelectronic characteristics of the IGZO/IZO phototransistors were identified by adjusting the ratio of In:Zn in the IZO layer. As a result, the most remarkable traits were observed at the ratio of In:Zn = 8:2. Compared to the IGZO single-layer phototransistor, the IGZO/IZO(8:2) phototransistor showed improved photoresponse characteristics, with photosensitivity and photoresponsivity values of 1.00 × 107 and 89.1 AW-1, respectively, under visible light wavelength illumination. Moreover, the electrical characteristics of the IGZO/IZO(8:2) transistor, such as field effect mobility (μsat) and current on/off ratio (Ion/Ioff), were highly enhanced compared to the IGZO transistor. The μsat and Ion/Ioff were increased by about 2.1 times and 2.3 times, respectively, compared to the IGZO transistor. This work provides an approach for fabricating visible-light phototransistors with elevated optoelectronic properties and low power consumption based on an oxide-oxide heterostructure. The phototransistor with improved performance can be applied to applications such as color-selective visible-light image sensors and biometric sensors interacting with human-machine interfaces.
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Affiliation(s)
- Yu Bin Kim
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17104, Republic of Korea; (Y.B.K.); (J.H.J.); (M.H.P.); (J.M.Y.); (J.H.M.); (H.J.H.); (S.J.K.)
| | - Jun Hyung Jeong
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17104, Republic of Korea; (Y.B.K.); (J.H.J.); (M.H.P.); (J.M.Y.); (J.H.M.); (H.J.H.); (S.J.K.)
- Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
| | - Min Ho Park
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17104, Republic of Korea; (Y.B.K.); (J.H.J.); (M.H.P.); (J.M.Y.); (J.H.M.); (H.J.H.); (S.J.K.)
- Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
| | - Jung Min Yun
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17104, Republic of Korea; (Y.B.K.); (J.H.J.); (M.H.P.); (J.M.Y.); (J.H.M.); (H.J.H.); (S.J.K.)
| | - Jin Hyun Ma
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17104, Republic of Korea; (Y.B.K.); (J.H.J.); (M.H.P.); (J.M.Y.); (J.H.M.); (H.J.H.); (S.J.K.)
- Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
| | - Hyoun Ji Ha
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17104, Republic of Korea; (Y.B.K.); (J.H.J.); (M.H.P.); (J.M.Y.); (J.H.M.); (H.J.H.); (S.J.K.)
- Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
| | - Seong Jae Kang
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17104, Republic of Korea; (Y.B.K.); (J.H.J.); (M.H.P.); (J.M.Y.); (J.H.M.); (H.J.H.); (S.J.K.)
- Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
| | - Seong Jun Kang
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17104, Republic of Korea; (Y.B.K.); (J.H.J.); (M.H.P.); (J.M.Y.); (J.H.M.); (H.J.H.); (S.J.K.)
- Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
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3
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Kim S, Kang SJ, Nguyen HS, Jeong SW. Store-operated calcium entry in the satellite glial cells of rat sympathetic ganglia. Korean J Physiol Pharmacol 2024; 28:93-103. [PMID: 38154968 PMCID: PMC10762485 DOI: 10.4196/kjpp.2024.28.1.93] [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] [Received: 12/04/2023] [Revised: 12/15/2023] [Accepted: 12/17/2023] [Indexed: 12/30/2023]
Abstract
Satellite glial cells (SGCs), a major type of glial cell in the autonomic ganglia, closely envelop the cell body and even the synaptic regions of a single neuron with a very narrow gap. This structurally unique organization suggests that autonomic neurons and SGCs may communicate reciprocally. Glial Ca2+ signaling is critical for controlling neural activity. Here, for the first time we identified the machinery of store-operated Ca2+ entry (SOCE) which is critical for cellular Ca2+ homeostasis in rat sympathetic ganglia under normal and pathological states. Quantitative realtime PCR and immunostaining analyses showed that Orai1 and stromal interaction molecules 1 (STIM1) proteins are the primary components of SOCE machinery in the sympathetic ganglia. When the internal Ca2+ stores were depleted in the absence of extracellular Ca2+, the number of plasmalemmal Orai1 puncta was increased in neurons and SGCs, suggesting activation of the Ca2+ entry channels. Intracellular Ca2+ imaging revealed that SOCE was present in SGCs and neurons; however, the magnitude of SOCE was much larger in the SGCs than in the neurons. The SOCE was significantly suppressed by GSK7975A, a selective Orai1 blocker, and Pyr6, a SOCE blocker. Lipopolysaccharide (LPS) upregulated the glial fibrillary acidic protein and Toll-like receptor 4 in the sympathetic ganglia. Importantly, LPS attenuated SOCE via downregulating Orai1 and STIM1 expression. In conclusion, sympathetic SGCs functionally express the SOCE machinery, which is indispensable for intracellular Ca2+ signaling. The SOCE is highly susceptible to inflammation, which may affect sympathetic neuronal activity and thereby autonomic output.
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Affiliation(s)
- Sohyun Kim
- Department of Physiology, Laboratory of Molecular Neurophysiology, Yonsei University Wonju College of Medicine, Wonju 26426, Korea
| | - Seong Jun Kang
- Department of Physiology, Laboratory of Molecular Neurophysiology, Yonsei University Wonju College of Medicine, Wonju 26426, Korea
| | - Huu Son Nguyen
- Department of Physiology, Laboratory of Molecular Neurophysiology, Yonsei University Wonju College of Medicine, Wonju 26426, Korea
| | - Seong-Woo Jeong
- Department of Physiology, Laboratory of Molecular Neurophysiology, Yonsei University Wonju College of Medicine, Wonju 26426, Korea
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Kim SH, Park KH, Lee YG, Kang SJ, Park Y, Kim YD. Color Centers in Hexagonal Boron Nitride. Nanomaterials (Basel) 2023; 13:2344. [PMID: 37630929 PMCID: PMC10458833 DOI: 10.3390/nano13162344] [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: 07/14/2023] [Revised: 08/10/2023] [Accepted: 08/13/2023] [Indexed: 08/27/2023]
Abstract
Atomically thin two-dimensional (2D) hexagonal boron nitride (hBN) has emerged as an essential material for the encapsulation layer in van der Waals heterostructures and efficient deep ultraviolet optoelectronics. This is primarily due to its remarkable physical properties and ultrawide bandgap (close to 6 eV, and even larger in some cases) properties. Color centers in hBN refer to intrinsic vacancies and extrinsic impurities within the 2D crystal lattice, which result in distinct optical properties in the ultraviolet (UV) to near-infrared (IR) range. Furthermore, each color center in hBN exhibits a unique emission spectrum and possesses various spin properties. These characteristics open up possibilities for the development of next-generation optoelectronics and quantum information applications, including room-temperature single-photon sources and quantum sensors. Here, we provide a comprehensive overview of the atomic configuration, optical and quantum properties, and different techniques employed for the formation of color centers in hBN. A deep understanding of color centers in hBN allows for advances in the development of next-generation UV optoelectronic applications, solid-state quantum technologies, and nanophotonics by harnessing the exceptional capabilities offered by hBN color centers.
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Affiliation(s)
- Suk Hyun Kim
- Department of Physics, Kyung Hee University, Seoul 02447, Republic of Korea; (S.H.K.)
- Department of Information Display, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Kyeong Ho Park
- Department of Physics, Kyung Hee University, Seoul 02447, Republic of Korea; (S.H.K.)
| | - Young Gie Lee
- Department of Physics, Kyung Hee University, Seoul 02447, Republic of Korea; (S.H.K.)
| | - Seong Jun Kang
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17101, Republic of Korea;
| | - Yongsup Park
- Department of Physics, Kyung Hee University, Seoul 02447, Republic of Korea; (S.H.K.)
- Department of Information Display, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Young Duck Kim
- Department of Physics, Kyung Hee University, Seoul 02447, Republic of Korea; (S.H.K.)
- Department of Information Display, Kyung Hee University, Seoul 02447, Republic of Korea
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5
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Jeong MW, Ma JH, Shin JS, Kim JS, Ma G, Nam TU, Gu X, Kang SJ, Oh JY. Intrinsically stretchable three primary light-emitting films enabled by elastomer blend for polymer light-emitting diodes. Sci Adv 2023; 9:eadh1504. [PMID: 37343088 DOI: 10.1126/sciadv.adh1504] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 05/18/2023] [Indexed: 06/23/2023]
Abstract
Intrinsically stretchable light-emitting materials are crucial for skin-like wearable displays; however, their color range has been limited to green-like yellow lights owing to the restricted stretchable light-emitting materials (super yellow series materials). To develop skin-like full-color displays, three intrinsically stretchable primary light-emitting materials [red, green, and blue (RGB)] are essential. In this study, we report three highly stretchable primary light-emitting films made from a polymer blend of conventional RGB light-emitting polymers and a nonpolar elastomer. The blend films consist of multidimensional nanodomains of light-emitting polymers that are interconnected in an elastomer matrix for efficient light-emitting under strain. The RGB blend films exhibited over 1000 cd/m2 luminance with low turn-on voltage (<5 Von) and the selectively stretched blend films on rigid substrate maintained stable light-emitting performance up to 100% strain even after 1000 multiple stretching cycles.
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Affiliation(s)
- Min Woo Jeong
- Department of Chemical Engineering (Integrated Engineering Program), Kyung Hee University, Yongin, Gyeonggi, 17104, Korea
| | - Jin Hyun Ma
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin, Gyeonggi, 17104, Korea
- Integrated Education Institute for Frontier Science and Technology (BK21 Four), Kyung Hee University, Yongin, Gyeonggi, 17104, Korea
| | - Jae Seung Shin
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin, Gyeonggi, 17104, Korea
- Integrated Education Institute for Frontier Science and Technology (BK21 Four), Kyung Hee University, Yongin, Gyeonggi, 17104, Korea
| | - Jun Su Kim
- Department of Chemical Engineering (Integrated Engineering Program), Kyung Hee University, Yongin, Gyeonggi, 17104, Korea
| | - Guorong Ma
- School of Polymer Science and Engineering, University of Southern Mississippi, Hattiesburg, MS 39406, USA
| | - Tae Uk Nam
- Department of Chemical Engineering (Integrated Engineering Program), Kyung Hee University, Yongin, Gyeonggi, 17104, Korea
| | - Xiaodan Gu
- School of Polymer Science and Engineering, University of Southern Mississippi, Hattiesburg, MS 39406, USA
| | - Seong Jun Kang
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin, Gyeonggi, 17104, Korea
- Integrated Education Institute for Frontier Science and Technology (BK21 Four), Kyung Hee University, Yongin, Gyeonggi, 17104, Korea
| | - Jin Young Oh
- Department of Chemical Engineering (Integrated Engineering Program), Kyung Hee University, Yongin, Gyeonggi, 17104, Korea
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Ma JH, Kim MG, Jeong JH, Park MH, Ha HJ, Kang SJ, Kang SJ. Highly Efficient ITO-Free Quantum-Dot Light Emitting Diodes via Solution-Processed PEDOT:PSS Semitransparent Electrode. Materials (Basel) 2023; 16:ma16114053. [PMID: 37297186 DOI: 10.3390/ma16114053] [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: 04/17/2023] [Revised: 05/22/2023] [Accepted: 05/26/2023] [Indexed: 06/12/2023]
Abstract
We present a study on the potential use of sulfuric acid-treated poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) as a viable alternative to indium tin oxide (ITO) electrodes in quantum dot light-emitting diodes (QLEDs). ITO, despite its high conductivity and transparency, is known for its disadvantages of being brittle, fragile, and expensive. Furthermore, due to the high hole injection barrier of quantum dots, the need for electrodes with a higher work function is becoming more significant. In this report, we present solution-processed, sulfuric acid-treated PEDOT:PSS electrodes for highly efficient QLEDs. The high work function of the PEDOT:PSS electrodes improved the performance of the QLEDs by facilitating hole injection. We demonstrated the recrystallization and conductivity enhancement of PEDOT:PSS upon sulfuric acid treatment using X-ray photoelectron spectroscopy and Hall measurement. Ultraviolet photoelectron spectroscopy (UPS) analysis of QLEDs showed that sulfuric acid-treated PEDOT:PSS exhibited a higher work function than ITO. The maximum current efficiency and external quantum efficiency based on the PEDOT:PSS electrode QLEDs were measured as 46.53 cd/A and 11.01%, which were three times greater than ITO electrode QLEDs. These findings suggest that PEDOT:PSS can serve as a promising replacement for ITO electrodes in the development of ITO-free QLED devices.
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Affiliation(s)
- Jin Hyun Ma
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17104, Republic of Korea
- Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
| | - Min Gye Kim
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17104, Republic of Korea
- Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
| | - Jun Hyung Jeong
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17104, Republic of Korea
- Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
| | - Min Ho Park
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17104, Republic of Korea
- Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
| | - Hyoun Ji Ha
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17104, Republic of Korea
- Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
| | - Seong Jae Kang
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17104, Republic of Korea
- Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
| | - Seong Jun Kang
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17104, Republic of Korea
- Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
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Park MH, Kim MG, Ma JH, Jeong JH, Ha HJ, Kim W, Park S, Kang SJ. Enhancing the Performance of Quantum Dot Light-Emitting Diodes Using Solution-Processable Highly Conductive Spinel Structure CuCo 2O 4 Hole Injection Layer. Materials (Basel) 2023; 16:972. [PMID: 36769979 PMCID: PMC9919813 DOI: 10.3390/ma16030972] [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] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 01/14/2023] [Accepted: 01/18/2023] [Indexed: 06/18/2023]
Abstract
Charge imbalance in quantum-dot light-emitting diodes (QLEDs) causes emission degradation. Therefore, many studies focused on improving hole injection into the QLEDs-emitting layer owing to lower hole conductivity compared to electron conductivity. Herein, CuCo2O4 has a relatively higher hole conductivity than other binary oxides and can induce an improved charge balance. As the annealing temperature decreases, the valence band maximum (VBM) of CuCo2O4 shifts away from the Fermi energy level (EF), resulting in an enhanced hole injection through better energy level alignment with hole transport layer. The maximum luminance and current efficiency of the CuCo2O4 hole injection layer (HIL) of the QLED were measured as 93,607 cd/m2 and 11.14 cd/A, respectively, resulting in a 656% improvement in luminous performance of QLEDs compared to conventional metal oxide HIL-based QLEDs. These results demonstrate that the electrical properties of CuCo2O4 can be improved by adjusting the annealing temperature, suggesting that solution-processed spinel can be applied in various optoelectronic devices.
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Affiliation(s)
- Min Ho Park
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17104, Republic of Korea
- Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
| | - Min Gye Kim
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17104, Republic of Korea
- Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
| | - Jin Hyun Ma
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17104, Republic of Korea
- Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
| | - Jun Hyung Jeong
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17104, Republic of Korea
- Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
| | - Hyoun Ji Ha
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17104, Republic of Korea
- Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
| | - Wonsik Kim
- Advanced Analysis Center, Korea Institute of Science and Technology, 5 Hwarang-ro 14-gil, Seongbuk-gu, Seoul 02792, Republic of Korea
| | - Soohyung Park
- Advanced Analysis Center, Korea Institute of Science and Technology, 5 Hwarang-ro 14-gil, Seongbuk-gu, Seoul 02792, Republic of Korea
- Division of Nano & Information Technology, KIST School, University of Science and Technology (UST), Seoul 02792, Republic of Korea
| | - Seong Jun Kang
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17104, Republic of Korea
- Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
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Jeong JH, Kim MG, Ma JH, Park MH, Ha HJ, Kang SJ, Maeng MJ, Kim YD, Park Y, Kang SJ. Improving the Performance of Solution-Processed Quantum Dot Light-Emitting Diodes via a HfO x Interfacial Layer. Materials (Basel) 2022; 15:8977. [PMID: 36556781 PMCID: PMC9781304 DOI: 10.3390/ma15248977] [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] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 12/11/2022] [Accepted: 12/14/2022] [Indexed: 06/17/2023]
Abstract
One of the major obstacles in the way of high-performance quantum dot light-emitting diodes (QLEDs) is the charge imbalance arising from more efficient electron injection into the emission layer than the hole injection. In previous studies, a balanced charge injection was often achieved by lowering the electron injection efficiency; however, high performance next-generation QLEDs require the hole injection efficiency to be enhanced to the level of electron injection efficiency. Here, we introduce a solution-processed HfOx layer for the enhanced hole injection efficiency. A large amount of oxygen vacancies in the HfOx films creates gap states that lower the hole injection barrier between the anode and the emission layer, resulting in enhanced light-emitting characteristics. The insertion of the HfOx layer increased the luminance of the device to 166,600 cd/m2, and the current efficiency and external quantum efficiency to 16.6 cd/A and 3.68%, respectively, compared with the values of 63,673 cd/m2, 7.37 cd/A, and 1.64% for the device without HfOx layer. The enhanced light-emitting characteristics of the device were elucidated by X-ray photoelectron, ultra-violet photoelectron, and UV-visible spectroscopy. Our results suggest that the insertion of the HfOx layer is a useful method for improving the light-emitting properties of QLEDs.
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Affiliation(s)
- Jun Hyung Jeong
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17101, Republic of Korea
- Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
| | - Min Gye Kim
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17101, Republic of Korea
- Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
| | - Jin Hyun Ma
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17101, Republic of Korea
- Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
| | - Min Ho Park
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17101, Republic of Korea
- Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
| | - Hyoun Ji Ha
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17101, Republic of Korea
- Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
| | - Seong Jae Kang
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17101, Republic of Korea
- Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
| | - Min-Jae Maeng
- Department of Physics and Research Institute of Basic Sciences, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Young Duck Kim
- Department of Physics and Research Institute of Basic Sciences, Kyung Hee University, Seoul 02447, Republic of Korea
- Department of Information Display, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Yongsup Park
- Department of Physics and Research Institute of Basic Sciences, Kyung Hee University, Seoul 02447, Republic of Korea
- Department of Information Display, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Seong Jun Kang
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin 17101, Republic of Korea
- Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University, Yongin 17104, Republic of Korea
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Moon J, Kang SJ, Noh JW. Evaluation of primary health care system in Yangon Region, Myanmar: a mixed-method approach. Eur J Public Health 2022. [DOI: 10.1093/eurpub/ckac131.016] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
Many low- and middle-income countries and international organizations have invested resources to strengthen primary health care services. Despite efforts from the Ministry of Health on primary health care, barriers to accessing health care services and health inequality in Myanmar still exist. This study aimed to identify the challenges and unmet needs in the current primary health care services by assessing the experiences and perceptions of healthcare workers and local leaders in three townships (Htantabin, Hmawbi, and Taikkyi) in Yangon, Myanmar.
Methods
The study was conducted among healthcare professionals and community leaders in three townships. By adopting a mixed-method approach, a cross-sectional health needs assessment survey was conducted for quantitative data (n = 66), and focus group discussions (15 group discussions) were conducted online for qualitative data.
Results
As a result of the survey regarding six domains; hygiene, primary medical care, maternal and child health, infectious diseases, non-communicable diseases, and leadership, enhancing the management and leadership capacity had the lowest average score on the current achievement (2.81 out of 5), while strengthening infectious disease control service and accessibility was perceived as the highest mean on the priority of intervention (4.28 out of 5) and the impact of the intervention (4.7). The focus group discussions revealed that while specific infrastructures and equipment necessary for the category were addressed, the need for financial support has been the recurrent theme throughout the discussions.
Conclusions
Utilizing the World Health Organization’s six-building block framework, our findings suggest that a long-term targeted financial investment in the primary health care system is critical in Myanmar by increasing health care expenditure per capita. At the same time, related barriers and facilitators should be considered to optimize the effectiveness of prioritized interventions.
Key messages
• Health care providers and local leaders perceived the management and leadership capacity as the lowest current achievement.
• A long-term targeted financial investment in the primary health care system is critical in Myanmar.
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Affiliation(s)
- J Moon
- Graduate School of Medical Sciences, University of Groningen , Groningen, Netherlands
| | - SJ Kang
- Institute of Health and Environment, Seoul National University , Seoul, South Korea
| | - JW Noh
- Division of Health Administration, Yonsei University , Wonju, South Korea
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10
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Seo SM, Kim SJ, Kwon O, Brilakis ES, Yoon YH, Lee KS, Kim TO, Lee PH, Kang SJ, Kim YH, Lee CW, Park SW, Lee SW. Intravascular ultrasound-guided optimization for chronic total occlusion-percutaneous coronary intervention with multiple drug-eluting stents. Eur Heart J 2022. [DOI: 10.1093/eurheartj/ehac544.2071] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
Multiple stenting in the chronic total occlusion (CTO) lesions is frequently required, however associated with poorer clinical outcomes. It is demonstrated that intravascular ultrasound (IVUS)-guided CTO-percutaneous coronary intervention (PCI) is related to a lower risk of adverse clinical events.
Purpose
We aimed to evaluate the clinical impact of stent optimization under IVUS guidance for multiple stenting, comparing with single stenting.
Methods
A total of 916 patients receiving drug-eluting stent (DES) under IVUS guidance were classified into two groups (stent optimization and non-optimization) according to optimization criteria (an absolute expansion criteria; minimal stent area ≥4.9 mm2 and a relative expansion criteria; 80% of mean reference lumen area). Of total population, 314 patients (34.3%) were treated with single stent and 575 patients (62.7%) were treated with multiple stents, respectively. Ischemic-driven target-lesion revascularization (TLR)/reocclusion was evaluated.
Results
Under IVUS guidance, 316 patients (34.5%) met IVUS criteria for stent optimization The achieving rates were 53% in the single stent group and 24% in the multiple stents group, respectively, (p<0.001). During a median of 4.7 years, the multiple stent group showed a significantly higher TLR/reocclusion rate, compared with the single stent group (12.8% vs. 5.2%, adjusted hazard ratio [HR] 2.51, 95% confidence interval [CI] 1.20–5.25, p=0.01). (Figure 1) Meeting both the absolute and relative expansion criteria was associated with a significantly low rate of TLR/reocclusion rate (12.5% vs. 5.2%, adjusted HR 0.34, 95% CI: 0.15–0.79, p=0.01). Under IVUS-guidance, there was no significant difference between multiple stenting and single stenting in case of achieving the optimization criteria (6.5% vs. 4.2%, p=0.11), whereas non-optimization group in the patients with multiple stenting showed a significantly higher rate of TLR/reocclusion, compared with IVUS-optimization group in the patients with single stenting (14.5% vs. 4.2%, p=0.002). (Figure 2)
Conclusions
In CTO-PCI with DES, multiple stenting significantly increased the risk of TLR/reocclusion. IVUS-guided optimization for multiple stenting showed a comparable long-term risk of TLR/reocclusion to single stenting with IVUS optimization. Hence, achieving IVUS expansion criteria may help to reduce the risk of TLR/reocclusion in CTO-PCI with multiple DES overlapping.
Funding Acknowledgement
Type of funding sources: None.
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Affiliation(s)
- S M Seo
- Eunpyeoung St. Mary's Hospital, Division of Cardiology, Department of Internal Medicine , Seoul , Korea (Republic of)
| | - S J Kim
- Eunpyeoung St. Mary's Hospital, Division of Cardiology, Department of Internal Medicine , Seoul , Korea (Republic of)
| | - O Kwon
- Eunpyeoung St. Mary's Hospital, Division of Cardiology, Department of Internal Medicine , Seoul , Korea (Republic of)
| | - E S Brilakis
- Minneapolis Heart Institute Foundation , Minneapolis , United States of America
| | - Y H Yoon
- Sejong Chungnam National University Hospital , Sejong , Korea (Republic of)
| | - K S Lee
- Daejeon St. Mary's Hospital , Daejeon , Korea (Republic of)
| | - T O Kim
- Asan Medical Center , Seoul , Korea (Republic of)
| | - P H Lee
- Asan Medical Center , Seoul , Korea (Republic of)
| | - S J Kang
- Asan Medical Center , Seoul , Korea (Republic of)
| | - Y H Kim
- Asan Medical Center , Seoul , Korea (Republic of)
| | - C W Lee
- Asan Medical Center , Seoul , Korea (Republic of)
| | - S W Park
- Asan Medical Center , Seoul , Korea (Republic of)
| | - S W Lee
- Asan Medical Center , Seoul , Korea (Republic of)
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11
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Lee WJ, Cho DH, Wi JH, Yu JH, Kim WJ, Kang C, Kang SJ, Chung YD. Evolution of Morphological and Chemical Properties at p-n Junction of Cu(In,Ga)Se 2 Solar Cells with Zn(O,S) Buffer Layer as a Function of KF Postdeposition Treatment Time. ACS Appl Mater Interfaces 2021; 13:48611-48621. [PMID: 34636529 DOI: 10.1021/acsami.1c12636] [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: 06/13/2023]
Abstract
We carried out KF postdeposition treatment (PDT) on a Cu(In,Ga)Se2 (CIGS) layer with a process time varying from 50 to 200 s. The highest CIGS solar-cell efficiency was achieved at a KF PDT process time of 50 s; in this condition, we observed the highest level of K element at the near-surface of the CIGS layer and the perfectly passivated pinholes on the CIGS surface. At process times above 150 s, the oversupplied KF agglomerated into large islands and was subsequently eliminated during the deposition of the chemical bath deposition (CBD)-Zn(O,S) buffer layer owing to the islands' water-soluble characteristics. As a result, the growth mechanism of the CBD-Zn(O,S) layer varied as a function of KF PDT process time. X-ray photoemission spectroscopy (XPS) measurements were used to examine the dependency of the chemical state on the KF PDT process time, and from the results, we formulated a chemical reaction model based on the shift in the elemental binding energy following deposition of the CBD-Zn(O,S) buffer layer. The chemical states of the K-In-Se phase, which have a beneficial effect on the solar-cell performance owing to the formation of durable and improved p-n junctions, are formed only at a KF PDT process time of 50 s. We derived band alignments from the XPS depth profiles by extracting the conduction- and valence-band offsets, and we used optical-pump-THz-probe spectroscopy to measure the ultrafast photocarrier lifetimes related to the defect states following KF PDT. Our key findings can be summarized as follows: (i) photocarrier transport is beneficial at a low barrier height, and (ii) the photocarrier lifetime increases when the K-In-Se phases are formed on the CIGS surface, which allows K+ ions to be effectively substituted into Cu vacancies.
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Affiliation(s)
- Woo-Jung Lee
- ICT Creative Research Laboratory, Electronics and Telecommunications Research Institute, Daejeon 34129, Korea
- Department of Advanced Device Technology, Korea University of Science and Technology, Daejeon 34113, Korea
| | - Dae-Hyung Cho
- ICT Creative Research Laboratory, Electronics and Telecommunications Research Institute, Daejeon 34129, Korea
- Department of Advanced Device Technology, Korea University of Science and Technology, Daejeon 34113, Korea
| | - Jae-Hyung Wi
- School of Electrical and Electronics Engineering, Chung-Ang University, Seoul 06974, Korea
| | - Jong Hun Yu
- ICT Creative Research Laboratory, Electronics and Telecommunications Research Institute, Daejeon 34129, Korea
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Gyeonggi-do 17104, Korea
| | - Woo-Ju Kim
- ICT Creative Research Laboratory, Electronics and Telecommunications Research Institute, Daejeon 34129, Korea
- Department of Advanced Device Technology, Korea University of Science and Technology, Daejeon 34113, Korea
| | - Chul Kang
- Advanced Photonics Research Institute, Gwangju Institute Science Technology, Gwangju 61005, Korea
| | - Seong Jun Kang
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Gyeonggi-do 17104, Korea
| | - Yong-Duck Chung
- ICT Creative Research Laboratory, Electronics and Telecommunications Research Institute, Daejeon 34129, Korea
- Department of Advanced Device Technology, Korea University of Science and Technology, Daejeon 34113, Korea
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12
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Kim BJ, Jeong JH, Jung EY, Kim TY, Park S, Hong JA, Lee KM, Jeon W, Park Y, Kang SJ. A visible-light phototransistor based on the heterostructure of ZnO and TiO 2 with trap-assisted photocurrent generation. RSC Adv 2021; 11:12051-12057. [PMID: 35423752 PMCID: PMC8696453 DOI: 10.1039/d1ra00801c] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [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: 01/30/2021] [Accepted: 03/12/2021] [Indexed: 12/27/2022] Open
Abstract
Visible-light phototransistors have been fabricated based on the heterojunction of zinc oxide (ZnO) and titanium oxide (TiO2). A thin layer of TiO2 was deposited onto the spin-coated ZnO film via atomic layer deposition (ALD). The electrical characteristics of the TiO2 layer were optimized by controlling the purge time of titanium isopropoxide (TTIP). The optimized TiO2 layer could absorb the visible-light from the sub-gap states near the conduction band of TiO2, which was confirmed via photoelectron spectroscopy measurements. Therefore, the heterostructure of TiO2/ZnO can absorb and generate photocurrent under visible light illumination. The oxygen-related-states were investigated via X-ray photoelectron spectroscopy (XPS), and the interfacial band structure between TiO2 and ZnO was evaluated via ultraviolet photoelectron spectroscopy (UPS). Oxygen-related states and subgap-states were observed, which could be used to generate photocurrent by absorbing visible light, even with TiO2 and ZnO having a wide bandgap. The optimized TiO2/ZnO visible-light phototransistor showed a photoresponsivity of 99.3 A W−1 and photosensitivity of 1.5 × 105 under the illumination of 520 nm wavelength light. This study provides a useful way to fabricate a visible-light phototransistor based on the heterostructure of wide bandgap oxide semiconductors. Visible-light phototransistors have been fabricated based on the heterojunction of zinc oxide (ZnO) and titanium oxide (TiO2).![]()
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Affiliation(s)
- Byung Jun Kim
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University Yongin 17104 Republic of Korea +82-31-201-3324.,Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University Yongin 17104 Republic of Korea
| | - Jun Hyung Jeong
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University Yongin 17104 Republic of Korea +82-31-201-3324.,Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University Yongin 17104 Republic of Korea
| | - Eui Young Jung
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University Yongin 17104 Republic of Korea +82-31-201-3324.,Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University Yongin 17104 Republic of Korea
| | - Tae Yeon Kim
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University Yongin 17104 Republic of Korea +82-31-201-3324.,Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University Yongin 17104 Republic of Korea
| | - Sungho Park
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University Yongin 17104 Republic of Korea +82-31-201-3324.,Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University Yongin 17104 Republic of Korea
| | - Jong-Am Hong
- Department of Physics and Research Institute for Basic Sciences, Kyung Hee University Seoul 02447 Republic of Korea
| | - Kyu-Myung Lee
- Department of Physics and Research Institute for Basic Sciences, Kyung Hee University Seoul 02447 Republic of Korea
| | - Woojin Jeon
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University Yongin 17104 Republic of Korea +82-31-201-3324.,Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University Yongin 17104 Republic of Korea
| | - Yongsup Park
- Department of Physics and Research Institute for Basic Sciences, Kyung Hee University Seoul 02447 Republic of Korea.,Department of Information Display, Kyung Hee University Seoul 02447 Republic of Korea
| | - Seong Jun Kang
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University Yongin 17104 Republic of Korea +82-31-201-3324.,Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University Yongin 17104 Republic of Korea
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13
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Shin JS, Kim TY, Heo SB, Hong JA, Park Y, Kang SJ. Improving the performance of quantum-dot light-emitting diodes via an organic-inorganic hybrid hole injection layer. RSC Adv 2021; 11:4168-4172. [PMID: 35424372 PMCID: PMC8694390 DOI: 10.1039/d0ra10422a] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [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: 12/11/2020] [Accepted: 01/13/2021] [Indexed: 11/30/2022] Open
Abstract
Poly(3,4-ethylenedioxythiophene):poly(styrene-sulfonate) (PEDOT:PSS) is a commonly used material for the hole injection layer (HIL) in quantum-dot light-emitting diodes (QLEDs). In this work, we improved the performance of the QLED by using an organic–inorganic hybrid HIL. The hybrid HIL was prepared by mixing PEDOT:PSS with vanadium oxide (V2O5), which is a transition-metal oxide (TMO). The hole injection properties of PEDOT:PSS were improved according to the amount of V2O5 mixed into the PEDOT:PSS. The maximum luminance and current efficiency were 36 198 cd m−2 and 13.9 cd A−1, respectively, when the ratio of PEDOT:PSS and V2O5 was 10 : 1. Moreover, the operating lifetime exceeded 300 h, which is 10 times longer than the lifetime of the device with only PEDOT:PSS HIL. The improvement was analyzed using ultraviolet and X-ray photoelectron spectroscopy. We found that the density of state (DOS) of PEDOT:PSS near the Fermi energy level was increased by mixing V2O5. Therefore, the increase of DOS improved the hole injection and the performance of QLEDs. The result shows that the hybrid HIL can improve the performance and the stability of QLEDs. The performance of the quantum-dot light-emitting diodes was improved by using an organic–inorganic hybrid hole injection layer.![]()
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Affiliation(s)
- Jae Seung Shin
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University Yongin 17104 Republic of Korea +82-31-201-3324.,Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University Yongin 17104 Republic of Korea
| | - Tae Yeon Kim
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University Yongin 17104 Republic of Korea +82-31-201-3324.,Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University Yongin 17104 Republic of Korea
| | - Su Been Heo
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University Yongin 17104 Republic of Korea +82-31-201-3324.,Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University Yongin 17104 Republic of Korea
| | - Jong-Am Hong
- Department of Physics and Research Institute for Basic Sciences, Kyung Hee University Seoul 02447 Republic of Korea
| | - Yongsup Park
- Department of Physics and Research Institute for Basic Sciences, Kyung Hee University Seoul 02447 Republic of Korea.,Department of Information Display, Kyung Hee University Seoul 02447 Republic of Korea
| | - Seong Jun Kang
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University Yongin 17104 Republic of Korea +82-31-201-3324.,Integrated Education Program for Frontier Materials (BK21 Four), Kyung Hee University Yongin 17104 Republic of Korea
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14
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Kim TY, Park S, Kim BJ, Heo SB, Yu JH, Shin JS, Hong JA, Kim BS, Kim YD, Park Y, Kang SJ. Dual-functional quantum-dots light emitting diodes based on solution processable vanadium oxide hole injection layer. Sci Rep 2021; 11:1700. [PMID: 33462375 PMCID: PMC7814015 DOI: 10.1038/s41598-021-81480-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 01/05/2021] [Indexed: 11/14/2022] Open
Abstract
Dual-functional quantum-dots light emitting diodes (QLEDs) have been fabricated using solution processable vanadium oxide (V2O5) hole injection layer to control the carrier transport behavior. The device shows selectable functionalities of photo-detecting and light-emitting behaviors according to the different operating voltage conditions. The device emitted a bright green light at the wavelength of 536 nm, and with the maximum luminance of 31,668 cd/m2 in a forward bias of 8.6 V. Meanwhile, the device could operate as a photodetector in a reverse bias condition. The device was perfectly turned off in a reverse bias, while an increase of photocurrent was observed during the illumination of 520 nm wavelength light on the device. The interfacial electronic structure of the device prepared with different concentration V2O5 solution was measured in detail using x-ray and ultraviolet photoelectron spectroscopy. Both the highest occupied molecular orbital and the gap state levels were moved closer to the Fermi level, according to increase the concentration of V2O5 solution. The change of gap state position enables to fabricate a dual-functional QLEDs. Therefore, the device could operate both as a photodetector and as a light-emitting diode with different applied bias. The result suggests that QLEDs can be used as a photosensor and as a light-emitting diode for the future display industry.
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Affiliation(s)
- Tae Yeon Kim
- Department of Advanced Materials Engineering for Information and Electronics (BK21 four), Kyung Hee University, Yongin, 17104, Korea
| | - Sungho Park
- Department of Advanced Materials Engineering for Information and Electronics (BK21 four), Kyung Hee University, Yongin, 17104, Korea
| | - Byung Jun Kim
- Department of Advanced Materials Engineering for Information and Electronics (BK21 four), Kyung Hee University, Yongin, 17104, Korea
| | - Su Been Heo
- Department of Advanced Materials Engineering for Information and Electronics (BK21 four), Kyung Hee University, Yongin, 17104, Korea
| | - Jong Hun Yu
- Department of Advanced Materials Engineering for Information and Electronics (BK21 four), Kyung Hee University, Yongin, 17104, Korea
| | - Jae Seung Shin
- Department of Advanced Materials Engineering for Information and Electronics (BK21 four), Kyung Hee University, Yongin, 17104, Korea
| | - Jong-Am Hong
- Department of Physics and Research Institute for Basic Sciences, Kyung Hee University, Seoul, 02447, Korea
| | - Beom-Su Kim
- Department of Physics and Research Institute for Basic Sciences, Kyung Hee University, Seoul, 02447, Korea
| | - Young Duck Kim
- Department of Physics and Research Institute for Basic Sciences, Kyung Hee University, Seoul, 02447, Korea
| | - Yongsup Park
- Department of Physics and Research Institute for Basic Sciences, Kyung Hee University, Seoul, 02447, Korea.
| | - Seong Jun Kang
- Department of Advanced Materials Engineering for Information and Electronics (BK21 four), Kyung Hee University, Yongin, 17104, Korea.
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15
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Kim BJ, Cho NK, Park S, Jeong S, Jeon D, Kang Y, Kim T, Kim YS, Han IK, Kang SJ. Highly transparent phototransistor based on quantum-dots and ZnO bilayers for optical logic gate operation in visible-light. RSC Adv 2020; 10:16404-16414. [PMID: 35498875 PMCID: PMC9052890 DOI: 10.1039/d0ra01756f] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [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: 02/24/2020] [Accepted: 04/08/2020] [Indexed: 01/22/2023] Open
Abstract
Highly transparent optical logic circuits operated with visible light signals are fabricated using phototransistors with a heterostructure comprised of an oxide semiconductor (ZnO) with a wide bandgap and quantum dots (CdSe/ZnS QDs) with a small bandgap. ZnO serves as a highly transparent active channel, while the QDs absorb visible light and generate photoexcited charge carriers. The induced charge carriers can then be injected into the ZnO conduction band from the QD conduction band, which enables current to flow to activate the phototransistor. The photoexcited charge transfer mechanism is investigated using time-resolved photoluminescence spectroscopy, scanning Kelvin probe microscopy, and ultraviolet photoelectron spectroscopy. Measurements show that carriers in the QD conduction band can transfer to the ZnO conduction band under visible light illumination due to a change in the Fermi energy level. Moreover, the barrier for electron injection into the ZnO conduction band from the QD conduction band is low enough to allow photocurrent generation in the QDs/ZnO phototransistor. Highly transparent NOT, NOR, and NAND optical logic circuits are fabricated using the QDs/ZnO heterostructure and transparent indium tin oxide electrodes. This work provides a means of developing highly transparent optical logic circuits that can operate under illumination with low-energy photons such as those found in visible light. The operation of highly transparent optical logic circuits composed of phototransistors with QDs/ZnO heterojunctions are demonstrated. Photoexcited charge transfer mechanism was confirmed for photoinduced carriers transfer at the QDs/ZnO interfaces.![]()
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Affiliation(s)
- Byung Jun Kim
- Department of Advanced Materials Engineering for Information and Electronics
- Kyung Hee University
- Yongin 17101
- Republic of Korea
| | - Nam-Kwang Cho
- Program in Nano Science and Technology
- Graduate School of Convergence Science and Technology
- Seoul National University
- Seoul 08826
- Republic of Korea
| | - Sungho Park
- Department of Advanced Materials Engineering for Information and Electronics
- Kyung Hee University
- Yongin 17101
- Republic of Korea
| | - Shinyoung Jeong
- Nanophotonics Research Center
- Korea Institute of Science and Technology (KIST)
- Seoul 02792
- Republic of Korea
| | - Dohyeon Jeon
- Department of Physics
- Hankuk University of Foreign Studies
- Yongin 17035
- Republic of Korea
| | - Yebin Kang
- Department of Physics
- Hankuk University of Foreign Studies
- Yongin 17035
- Republic of Korea
| | - Taekyeong Kim
- Department of Physics
- Hankuk University of Foreign Studies
- Yongin 17035
- Republic of Korea
| | - Youn Sang Kim
- Program in Nano Science and Technology
- Graduate School of Convergence Science and Technology
- Seoul National University
- Seoul 08826
- Republic of Korea
| | - Il Ki Han
- Nanophotonics Research Center
- Korea Institute of Science and Technology (KIST)
- Seoul 02792
- Republic of Korea
| | - Seong Jun Kang
- Department of Advanced Materials Engineering for Information and Electronics
- Kyung Hee University
- Yongin 17101
- Republic of Korea
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16
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Seok HJ, Kang YJ, Kim J, Kim DH, Heo SB, Kang SJ, Kim HK. Tetrahedral amorphous carbon prepared filter cathodic vacuum arc for hole transport layers in perovskite solar cells and quantum dots LEDs. Sci Technol Adv Mater 2019; 20:1118-1130. [PMID: 32002086 PMCID: PMC6968577 DOI: 10.1080/14686996.2019.1694841] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 11/15/2019] [Accepted: 11/16/2019] [Indexed: 06/10/2023]
Abstract
(ta-C) films coated through the filtered cathodic vacuum arc (FCVA) process as a hole transport layer (HTL) for perovskite solar cells (PSCs) and quantum dot light-emitting diodes (QDLEDs). The p-type ta-C film has several remarkable features, including ease of fabrication without the need for thermal annealing, reasonable electrical conductivity, optical transmittance, and a high work function. X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy examinations show that the electrical properties (sp3/sp2 hybridized bond) and work function of the ta-C HTL are appropriate for PSCs and QDLEDs. In addition, in order to correlate the performance of the devices, the optical, surface morphological, and structural properties of the FCVA-grown ta-C films with different thicknesses (5 ~ 20 nm) deposited on the ITO anode are investigated in detail. The optimized ta-C film with a thickness of 5 nm deposited on the ITO anode had a sheet resistance of 10.33 Ω-2, a resistivity of 1.34 × 10-4 Ω cm, and an optical transmittance of 88.97%. Compared to the reference PSC with p-NiO HTL, the PSC with 5 nm thick ta-C HTL yielded a higher power conversion efficiency (PCE, 10.53%) due to its improved fill factor. Further, the performance of QDLEDs with 5 nm thick ta-C hole injection layers (HIL) showed better than the performance of QDLEDs with different ta-C thicknesses. It is concluded that ta-C films have the potential to serve as HTL and HIL in next-generation PSCs and QDLEDs.
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Affiliation(s)
- Hae-Jun Seok
- School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon-si, Republic of Korea
| | - Yong-Jin Kang
- Surface Engineering Department, Implementation Research Division, Korea Institute of Materials Science (KIMS), Changwon-Si, Republic of Korea
| | - Jongkuk Kim
- Surface Engineering Department, Implementation Research Division, Korea Institute of Materials Science (KIMS), Changwon-Si, Republic of Korea
| | - Do-Hyeong Kim
- Energy & New Industry Laboratory, Korea Electric Power Research Institute, Daejeon, Republic of Korea
| | - Su Been Heo
- Department of Advanced Materials Engineering for Information and Electronics, Kyung-Hee University, Yongin-si, Republic of Korea
| | - Seong Jun Kang
- Department of Advanced Materials Engineering for Information and Electronics, Kyung-Hee University, Yongin-si, Republic of Korea
| | - Han-Ki Kim
- School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon-si, Republic of Korea
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17
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Heo SB, Yu JH, Kim M, Yi Y, Lee JE, Kim HK, Kang SJ. Interfacial electronic structure between a W-doped In 2O 3 transparent electrode and a V 2O 5 hole injection layer for inorganic quantum-dot light-emitting diodes. RSC Adv 2019; 9:11996-12000. [PMID: 35516983 PMCID: PMC9063512 DOI: 10.1039/c9ra01520e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [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: 02/28/2019] [Accepted: 04/11/2019] [Indexed: 11/29/2022] Open
Abstract
The interfacial electronic structure between a W-doped In2O3 (IWO) transparent electrode and a V2O5 hole injection layer (HIL) has been investigated using ultraviolet photoelectron spectroscopy for high-performance and inorganic quantum-dot light-emitting diodes (QLEDs). Based on the interfacial electronic structure measurements, we found gap states in a V2O5 HIL at 1.0 eV below the Fermi level. Holes can be efficiently injected from the IWO electrode into poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4′-(4-sec-butylphenyl)diphenylamine)] (TFB) through the gap states of V2O5, which was confirmed by the hole injection characteristics of a hole-only device. Therefore, conventional normal-structured QLEDs were fabricated on a glass substrate with the IWO transparent electrode and V2O5 HIL. The maximum luminance of the device was measured as 9443.5 cd m−2. Our result suggests that the IWO electrode and V2O5 HIL are a good combination for developing high-performance and inorganic QLEDs. Interfacial electronic structure between W-doped In2O3 and V2O5 has been investigated, and we found gap states that can provide an efficient hole carrier injection pathway.![]()
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Affiliation(s)
- Su Been Heo
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University 1732 Deogyeong-daero, Giheung-gu Yongin Gyeonggi-do 17104 Republic of Korea +82-31-201-3324
| | - Jong Hun Yu
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University 1732 Deogyeong-daero, Giheung-gu Yongin Gyeonggi-do 17104 Republic of Korea +82-31-201-3324
| | - Minju Kim
- Institute of Physics and Applied Physics, Yonsei University 50 Yonsei-ro, Seodaemun-gu Seoul 03722 Republic of Korea
| | - Yeonjin Yi
- Institute of Physics and Applied Physics, Yonsei University 50 Yonsei-ro, Seodaemun-gu Seoul 03722 Republic of Korea
| | - Ji-Eun Lee
- School of Advanced Materials & Engineering, Sungkyunkwan University 2066 Seobu-ro, Jangan-gu Suwon Gyeonggi-do 16419 Republic of Korea
| | - Han-Ki Kim
- School of Advanced Materials & Engineering, Sungkyunkwan University 2066 Seobu-ro, Jangan-gu Suwon Gyeonggi-do 16419 Republic of Korea
| | - Seong Jun Kang
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University 1732 Deogyeong-daero, Giheung-gu Yongin Gyeonggi-do 17104 Republic of Korea +82-31-201-3324
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Jeong S, Kyhm J, Cha SK, Hwang DK, Ju BK, Park JS, Kang SJ, Han IK. High-Speed Colloidal Quantum Dot Photodiodes via Accelerating Charge Separation at Metal-Oxide Interface. Small 2019; 15:e1900008. [PMID: 30828958 DOI: 10.1002/smll.201900008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 02/01/2019] [Indexed: 06/09/2023]
Abstract
With ever-growing technological demands in the imaging sensor industry for autonomous driving and augmented reality, developing sensors that can satisfy not only image resolution but also the response speed becomes more challenging. Herein, the focus is on developing a high-speed photosensor capable of obtaining high-resolution, high-speed imaging with colloidal quantum dots (QDs) as the photosensitive material. In detail, high-speed QD photodiodes are demonstrated with rising and falling times of τr = 28.8 ± 8.34 ns and τf = 40 ± 9.81 ns, respectively, realized by fast separation of electron-hole pairs due to the action of internal electric field at the QD interface, mainly by the interaction between metal oxide and the QD's ligands. Such energy transfer relations are analyzed and interpreted with time-resolved photoluminescence measurements, providing physical understanding of the device and working principles.
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Affiliation(s)
- ShinYoung Jeong
- Nanophotonics Research Center, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
- School of Electrical Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Jihoon Kyhm
- Quantum-functional Semiconductor Research Center, Dongguk University, Seoul, 04620, Republic of Korea
| | - Soon-Kyu Cha
- Nanophotonics Research Center, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
- Department of Converging Science and Technology, Kyung Hee University, Seoul, 02453, Republic of Korea
| | - Do Kyung Hwang
- Nanophotonics Research Center, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
| | - Byeong-Kwon Ju
- School of Electrical Engineering, Korea University, Seoul, 02841, Republic of Korea
| | - Joon-Suh Park
- Nanophotonics Research Center, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, 02138, USA
| | - Seong Jun Kang
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin, 17104, Republic of Korea
| | - Il Ki Han
- Nanophotonics Research Center, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea
- Department of Converging Science and Technology, Kyung Hee University, Seoul, 02453, Republic of Korea
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Kim BJ, Park S, Cha SK, Han IK, Kang SJ. A near-infrared photoinverter based on ZnO and quantum-dots. RSC Adv 2018; 8:23421-23425. [PMID: 35540154 PMCID: PMC9081654 DOI: 10.1039/c8ra03588a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [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: 04/26/2018] [Accepted: 06/20/2018] [Indexed: 11/21/2022] Open
Abstract
Near-infrared (NIR) photoswitching transistors have been fabricated using a hybrid structure of zinc oxide (ZnO) and quantum-dots (QDs). The ZnO active layer was prepared using a solution process, while colloidal QDs were inserted between a silicon dioxide (SiO2) gate insulator and a ZnO active layer. The small band gap QDs (1.59 eV) were used to absorb low-energy NIR photons, generate photo-excited carriers, and inject them into the conduction band of the ZnO film. The device with the interfacial QDs induced photocurrents upon exposure to 780 nm-wavelength light. The photoresponsivity of the ZnO/QD device was 0.06 mA W−1, while that of the device without QDs was 1.7 × 10−5 mA W−1, which indicated that the small band gap QDs enabled a photo-induced current when exposed to NIR light. Furthermore, a photoinverter was prepared which was composed of a ZnO/QDs phototransistor and a load resistor. Photoswitching characteristics indicated that the photoinverter was well modulated by a periodic light signal of 780 nm in wavelength. The results demonstrate a useful way to fabricate NIR optoelectronics based on ZnO and QDs. A near-infrared photoinverter was fabricated based on ZnO and quantum-dots. We found that the small band gap quantum-dots could absorb low-energy near-infrared photons, generate photo-excited carriers, and inject them into the conduction band of ZnO.![]()
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Affiliation(s)
- Byung Jun Kim
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University Yongin 17104 Republic of Korea +82-31-201-3324
| | - Sungho Park
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University Yongin 17104 Republic of Korea +82-31-201-3324
| | - Soon Kyu Cha
- KHU-KIST Department of Converging Science and Technology, Kyung Hee University Seoul 02447 Republic of Korea
| | - Il Ki Han
- Nanophotonics Research Center, Korea Institute of Science and Technology Seoul 02792 Republic of Korea
| | - Seong Jun Kang
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University Yongin 17104 Republic of Korea +82-31-201-3324
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Liu T, Bao FL, Kang SJ, Jiang T, Huang DS, Gao W, Geng LJ, Hu YM. [Operative strategy and clinical results of complex four part distal radius fractures by combined palmar and dorsal internal fixation]. Zhonghua Wai Ke Za Zhi 2018. [PMID: 29534411 DOI: 10.3760/cma.j.issn.0529-5815.2018.03.004] [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] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To explore a standard procedure for the treatment of combined dorsal and palmar internal fixation for complex four part distal radius fractures and assess its clinical results. Methods: From May 2009 to October 2016, 38 patients(39 sides)who suffered from complex four part distal radius fractures were performed operatively with open reduction and internal fixation via combined dorsal and palmar approach in Department of Orthopaedic Trauma, Qilu Hospital of Shandong University(Qingdao). The series included 22 males(22 sides) and 16 females(17 sides). Age of the patients was 53.5 years ranging from 25 to 79 years.According to Melone classification, there were 34 sides of type of Ⅳ, 5 of type Ⅴ.According to Frykman classification, there were 15 sides of type Ⅶ, 24 sides of type Ⅷ, and all the cases were type C3 according to AO/OTA classification.Preoperatively, the key articular fragments in four part distal radius fractures were identified and the individual fracture patterns from conventional X-ray and CT-scan were analyzed. All the patients were performed combined volar and dorsal fixation.Firstly, a palmar approach which gave access to and fix the palmar-ulnar fragment and the radial styloid fragment was performed.Then a limited dorsal approach across the third extensor compartment which gave access to the dorso-ulnar fragment and a limited dorsal arthrotomy to visualize the radiocarpal joint when necessary were performed.Through dorsal approach, we can address the dorso-ulnar fragment, free intra-articular fragment and direct visualize the joint.Use of a retinacular flap was routinely advocated to help prevent against tendon irritation and rupture.The follow-up control included conventional X-ray, range of motion(ROM), grip strength, and the disabilities of the arm, shoulder and hand index(DASH), as well as the patient-rated wrist evaluation(PRWE) score for functional outcome at 6 and 12 months. Results: Thirty-three patients(34 sides) were followed up for at least 12 months.The would healed well in all cases 2 weeks postoperatively, and no soft tissue infections, necrosis or neurovascular complications occurred.All the fractures of 38 cases(39 sides)healed averaged 3.6 months(ranging from 2.5-5.7 months), and no loss of reduction occurred postoperatively.Anatomic reconstruction with a step or gap of <1 mm was achieved in 37 cases(38 sides), Whereas 5 patients were lost to follow-up at 12 months postoperatively.ROM and grip strength were all recovered to over 85% of the unaffected side(exception of the bilateral patient). Median DASH-index and PRWE were 6.5(0-17) and 9.3(0-20)respectively. Conclusion: Combined volar and dorsal approaches allow achieving anatomic reconstruction in complex four part intra-articular distal radius fractures and reveal good functional outcomes at intermediate follow-up.
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Affiliation(s)
- T Liu
- Department of Orthopaedic Trauma, Qilu Hospital of Shandong University(Qingdao), Qingdao 266035, China
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Chae MR, Kang SJ, Lee KP, Choi BR, Kim HK, Park JK, Kim CY, Lee SW. Onion (Allium cepa L.) peel extract (OPE) regulates human sperm motility via protein kinase C-mediated activation of the human voltage-gated proton channel. Andrology 2017; 5:979-989. [PMID: 28805023 DOI: 10.1111/andr.12406] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 06/13/2017] [Accepted: 06/27/2017] [Indexed: 01/14/2023]
Abstract
Onion (Allium cepa L.) and quercetin protect against oxidative damage and have positive effects on multiple functional parameters of spermatozoa, including viability and motility. However, the associated underlying mechanisms of action have not yet been identified. The aim of this study was to investigate the effect of onion peel extract (OPE) on voltage-gated proton (Hv1) channels, which play a critical role in rapid proton extrusion. This process underlies a wide range of physiological processes, particularly male fertility. The whole-cell patch-clamp technique was used to record the changes in Hv1 currents in HEK293 cells transiently transfected with human Hv1 (HVCN1). The effects of OPE on human sperm motility were also analyzed. OPE significantly activated the outward-rectifying proton currents in a concentration-dependent manner, with an EC50 value of 30 μg/mL. This effect was largely reversible upon washout. Moreover, OPE induced an increase in the proton current amplitude and decreased the time constant of activation at 0 mV from 4.9 ± 1.7 to 0.6 ± 0.1 sec (n = 6). In the presence of OPE, the half-activation voltage (V1/2 ) shifted in the negative direction, from 20.1 ± 5.8 to 5.2 ± 8.7 mV (n = 6), but the slope was not significantly altered. The OPE-induced current was profoundly inhibited by 10 μm Zn2+ , the most potent Hv1 channel inhibitor, and was also inhibited by treatment with GF109203X, a specific protein kinase C (PKC) inhibitor. Furthermore, sperm motility was significantly increased in the OPE-treated groups. OPE exhibits protective effects on sperm motility, at least partially via regulation of the proton channel. Moreover, similar effects were exerted by quercetin, the major flavonoid in OPE. These results suggest OPE, which is rich in the potent Hv1 channel activator quercetin, as a possible new candidate treatment for human infertility.
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Affiliation(s)
- M R Chae
- Department of Urology, Samsung Medical Center, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - S J Kang
- Department of Urology, Samsung Medical Center, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - K P Lee
- Laboratory of Physiology, College of Veterinary Medicine, Chungnam National University, Daejeon, Korea
| | - B R Choi
- Department of Urology, Medical School and Institute for Medical Sciences, Chonbuk National University, Research Institute and Clinical Trial Center of Medical Device of Chonbuk National University Hospital, Jeonju, Korea
| | - H K Kim
- College of Pharmacy, Kyungsung University, Busan, Korea
| | - J K Park
- Department of Urology, Medical School and Institute for Medical Sciences, Chonbuk National University, Research Institute and Clinical Trial Center of Medical Device of Chonbuk National University Hospital, Jeonju, Korea
| | - C Y Kim
- College of Pharmacy and Institute of Pharmaceutical Science and Technology, Hanyang University, Ansan, Korea
| | - S W Lee
- Department of Urology, Samsung Medical Center, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Seoul, Korea
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Choo SH, Lee SW, Chae MR, Kang SJ, Sung HH, Han DH, Chun JN, Park JK, Kim CY, Kim HK, So I. Effects of eupatilin on the contractility of corpus cavernosal smooth muscle through nitric oxide-independent pathways. Andrology 2017; 5:1016-1022. [PMID: 28719725 DOI: 10.1111/andr.12397] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [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: 02/02/2017] [Revised: 05/26/2017] [Accepted: 06/09/2017] [Indexed: 12/19/2022]
Abstract
Eupatilin (5,7-dihydroxy-3,4,6-trimethoxyflavone) is one of the main compounds present in Artemisia species. Eupatilin has both antioxidative and anti-inflammatory properties and a relaxation effect on vascular contraction regardless of endothelial function. We evaluated the relaxant effects of eupatilin on the corpus cavernosum (CC) of rabbits and the underlying mechanisms of its activity in human corpus cavernosum smooth muscle (CCSM) cells. Isolated rabbit CC strips were mounted in an organ bath system. A conventional whole-cell patch clamp technique was used to measure activation of calcium-sensitive K+ -channel currents in human CCSM cells. The relaxation effect of eupatilin was evaluated by cumulative addition (10-5 m ~ 3 × 10-4 m) to CC strips precontracted with 10-5 m phenylephrine. Western blotting analysis was performed to measure myosin phosphatase targeting subunit 1 (MYPT1) and protein kinase C-potentiated inhibitory protein for heterotrimeric myosin light chain phosphatase of 17-kDa (CPI-17) expression and to evaluate the effect of eupatilin on the RhoA/Rho-kinase pathway. Eupatilin effectively relaxed the phenylephrine-induced tone in the rabbit CC strips in a concentration-dependent manner with an estimated EC50 value of 1.2 ± 1.6 × 10-4 m (n = 8, p < 0.05). Iberiotoxin and tetraethylammonium significantly reduced the relaxation effect (n = 8, p < 0.001 and p = 0.003, respectively). Removal of the endothelium or the presence of L-NAME or indomethacin did not affect the relaxation effect of eupatilin. In CCSM cells, the extracellular application of eupatilin 10-4 m significantly increased the outward currents, and the eupatilin-stimulated currents were significantly attenuated by treatment with 10-7 m iberiotoxin (n = 13, p < 0.05). Eupatilin reduced the phosphorylation level of MYPT1 at Thr853 of MLCP and CPI-17 at Thr38. Eupatilin-induced relaxation of the CCSM cells via NO-independent pathways. The relaxation effects of eupatilin on CCSM cells were partially due to activation of BKCa channels and inhibition of RhoA/Rho-kinase.
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Affiliation(s)
- S H Choo
- Department of Urology, Ajou University School of Medicine, Suwon, Korea
| | - S W Lee
- Department of Urology, Samsung Medical Center, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - M R Chae
- Department of Urology, Samsung Medical Center, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - S J Kang
- Department of Urology, Samsung Medical Center, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - H H Sung
- Department of Urology, Samsung Medical Center, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - D H Han
- Department of Urology, Samsung Medical Center, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - J N Chun
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul, Korea
| | - J K Park
- Department of Urology, Institute for Medical Sciences, Medical School, Chonbuk National University, Research Institute and Clinical Trial Center of Medical Device of Chonbuk National University Hospital, Jeonju, Korea
| | - C Y Kim
- College of Pharmacy and Institute of Pharmaceutical Science and Technology, Hanyang University, Ansan, Korea
| | - H K Kim
- College of Pharmacy, Kyungsung University, Busan, Korea
| | - I So
- Department of Physiology, Seoul National University College of Medicine, Seoul, Korea
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Bae JY, Kim CJ, Kim UJ, Song KH, Kim ES, Kang SJ, Oh MD, Park KH, Kim NJ. Concordance of results of blood and tissue cultures from patients with pyogenic spondylitis: a retrospective cohort study. Clin Microbiol Infect 2017; 24:279-282. [PMID: 28698035 DOI: 10.1016/j.cmi.2017.07.005] [Citation(s) in RCA: 7] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 06/06/2017] [Accepted: 07/03/2017] [Indexed: 01/18/2023]
Abstract
OBJECTIVES To investigate the concordance of results of blood and tissue cultures in patients with pyogenic spondylitis. METHODS We searched for patients with pyogenic spondylitis in whom microorganisms were isolated from both blood and tissue cultures by retrospective review of medical records in three tertiary university-affiliated hospitals between January 2005 and December 2015. The species and antimicrobial susceptibility patterns of isolates from blood and tissue cultures were compared. RESULTS Among 141 patients with pyogenic spondylitis in whom microorganisms were isolated from both blood and tissue cultures, the species of blood and tissue isolates were identical in 135 patients (95.7%, 135/141). Excluding the four anaerobic isolates, we investigated antimicrobial susceptibility patterns of 131 isolates of the same species from blood and tissue cultures. Antibiotic susceptibility patterns were identical in 128 patients (97.7%, 128/131). The most common isolates were Staphylococcus aureus (86 patients; 85 concordant and one discordant), followed by streptococcus (24 patients; 22 concordant and two discordant), and Escherichia coli (eight patients; all concordant). CONCLUSIONS We suggest that a positive blood culture from patients with pyogenic spondylitis could preclude the need for additional tissue cultures, especially when S. aureus and streptococcus grew in blood cultures.
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Affiliation(s)
- J Y Bae
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - C-J Kim
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - U J Kim
- Department of Infectious Diseases, Chonnam National University Medical School, Gwang-ju, Republic of Korea
| | - K-H Song
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - E S Kim
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - S J Kang
- Department of Infectious Diseases, Chonnam National University Medical School, Gwang-ju, Republic of Korea
| | - M-D Oh
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - K-H Park
- Department of Infectious Diseases, Chonnam National University Medical School, Gwang-ju, Republic of Korea.
| | - N J Kim
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
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Oh E, Park S, Jeong J, Kang SJ, Lee H, Yi Y. Energy level alignment at the interface of NPB/HAT-CN/graphene for flexible organic light-emitting diodes. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2016.12.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Lee CY, Kang SJ, Hong SK, Ma HI, Lee U, Kim YJ. A Validation Study of a Smartphone-Based Finger Tapping Application for Quantitative Assessment of Bradykinesia in Parkinson's Disease. PLoS One 2016; 11:e0158852. [PMID: 27467066 PMCID: PMC4965104 DOI: 10.1371/journal.pone.0158852] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2016] [Accepted: 05/23/2016] [Indexed: 11/19/2022] Open
Abstract
Background Most studies of smartphone-based assessments of motor symptoms in Parkinson’s disease (PD) focused on gait, tremor or speech. Studies evaluating bradykinesia using wearable sensors are limited by a small cohort size and study design. We developed an application named smartphone tapper (SmT) to determine its applicability for clinical purposes and compared SmT parameters to current standard methods in a larger cohort. Methods A total of 57 PD patients and 87 controls examined with motor UPDRS underwent timed tapping tests (TT) using SmT and mechanical tappers (MeT) according to CAPSIT-PD. Subjects were asked to alternately tap each side of two rectangles with an index finger at maximum speed for ten seconds. Kinematic measurements were compared between the two groups. Results The mean number of correct tapping (MCoT), mean total distance of finger movement (T-Dist), mean inter-tap distance, and mean inter-tap dwelling time (IT-DwT) were significantly different between PD patients and controls. MCoT, as assessed using SmT, significantly correlated with motor UPDRS scores, bradykinesia subscores and MCoT using MeT. Multivariate analysis using the SmT parameters, such as T-Dist or IT-DwT, as predictive variables and age and gender as covariates demonstrated that PD patients were discriminated from controls. ROC curve analysis of a regression model demonstrated that the AUC for T-Dist was 0.92 (95% CI 0.88–0.96). Conclusion Our results suggest that a smartphone tapping application is comparable to conventional methods for the assessment of motor dysfunction in PD and may be useful in clinical practice.
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Affiliation(s)
- Chae Young Lee
- Department of Neurology, Hallym University Sacred Heart hospital, Hallym University College of Medicine, Hallym University, Anyang, Korea
| | - Seong Jun Kang
- Department of Electronic Engineering, Hallym University, Chuncheon, Korea
| | - Sang-Kyoon Hong
- Hallym Institute of Translational Genomics & Bioinformatics, Hallym University Medical Center, Anyang, Korea
| | - Hyeo-Il Ma
- Department of Neurology, Hallym University Sacred Heart hospital, Hallym University College of Medicine, Hallym University, Anyang, Korea
- * E-mail: (HIM); (UL); (YJK)
| | - Unjoo Lee
- Department of Electronic Engineering, Hallym University, Chuncheon, Korea
- * E-mail: (HIM); (UL); (YJK)
| | - Yun Joong Kim
- Department of Neurology, Hallym University Sacred Heart hospital, Hallym University College of Medicine, Hallym University, Anyang, Korea
- Hallym Institute of Translational Genomics & Bioinformatics, Hallym University Medical Center, Anyang, Korea
- ILSONG Institute of Life Science, Hallym University, Anyang, Korea
- * E-mail: (HIM); (UL); (YJK)
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Abstract
ITGO TFT were fabricated to study the photoresponses of indium-based oxide semiconductors. We found that the increased amount and low electron binding energy of indium can improve the recovery time of ITGO TFTs.
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Affiliation(s)
- Seung Won Shin
- Department of Advanced Materials Engineering for Information and Electronics
- Kyung Hee University
- Yongin
- Republic of Korea
| | - Jae Eun Cho
- Department of Advanced Materials Engineering for Information and Electronics
- Kyung Hee University
- Yongin
- Republic of Korea
| | - Hyun-Mo Lee
- Division of Materials Science and Engineering
- Hanyang University
- Seoul 04763
- Republic of Korea
| | - Jin-Seong Park
- Division of Materials Science and Engineering
- Hanyang University
- Seoul 04763
- Republic of Korea
| | - Seong Jun Kang
- Department of Advanced Materials Engineering for Information and Electronics
- Kyung Hee University
- Yongin
- Republic of Korea
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Shin SW, Lee KH, Park JS, Kang SJ. Highly Transparent, Visible-Light Photodetector Based on Oxide Semiconductors and Quantum Dots. ACS Appl Mater Interfaces 2015; 7:19666-71. [PMID: 26293387 DOI: 10.1021/acsami.5b04683] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Highly transparent phototransistors that can detect visible light have been fabricated by combining indium-gallium-zinc oxide (IGZO) and quantum dots (QDs). A wide-band-gap IGZO film was used as a transparent semiconducting channel, while small-band-gap QDs were adopted to absorb and convert visible light to an electrical signal. Typical IGZO thin-film transistors (TFTs) did not show a photocurrent with illumination of visible light. However, IGZO TFTs decorated with QDs showed enhanced photocurrent upon exposure to visible light. The device showed a responsivity of 1.35×10(4) A/W and an external quantum efficiency of 2.59×10(4) under illumination by a 635 nm laser. The origin of the increased photocurrent in the visible light was the small band gap of the QDs combined with the transparent IGZO films. Therefore, transparent phototransistors based on IGZO and QDs were fabricated and characterized in detail. The result is relevant for the development of highly transparent photodetectors that can detect visible light.
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Affiliation(s)
- Seung Won Shin
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University , 1732 Deogyeong-daero, Giheung-gu, Yongin, Gyeonggi-do 446-701, Republic of Korea
| | - Kwang-Ho Lee
- Division of Materials Science and Engineering, Hanyang University , 222 Wangsimni-ro, Seoul 133-719, Republic of Korea
| | - Jin-Seong Park
- Division of Materials Science and Engineering, Hanyang University , 222 Wangsimni-ro, Seoul 133-719, Republic of Korea
| | - Seong Jun Kang
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University , 1732 Deogyeong-daero, Giheung-gu, Yongin, Gyeonggi-do 446-701, Republic of Korea
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Lee YK, Lee TS, Song IH, Jeong HY, Kang SJ, Kim MW, Ryu SH, Jung IH, Kim JS, Park YS. Inhibition of pulmonary cancer progression by epidermal growth factor receptor-targeted transfection with Bcl-2 and survivin siRNAs. Cancer Gene Ther 2015; 22:335-43. [DOI: 10.1038/cgt.2015.18] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 02/26/2015] [Accepted: 02/27/2015] [Indexed: 01/20/2023]
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Cha MJ, Kim SM, Kang SJ, Seo JH, Walker B. Improved performance in flexible organic solar cells via optimization of highly transparent silver grid/graphene electrodes. RSC Adv 2015. [DOI: 10.1039/c5ra10838a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [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
Organic solar cells were fabricated on polyethylene terephthalate (PET) substrates using hybrid silver grid/graphene films as transparent conducting electrodes and the effect of the silver grid dimensions was characterized.
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Affiliation(s)
- Myoung Joo Cha
- Department of Materials Physics
- DONG-A University
- Busan 604-714
- Republic of Korea
- School of Energy and Chemical Engineering
| | - Sung Man Kim
- Department of Advanced Materials Engineering for Information and Electronics
- Kyung Hee University
- Yongin
- Republic of Korea
| | - Seong Jun Kang
- Department of Advanced Materials Engineering for Information and Electronics
- Kyung Hee University
- Yongin
- Republic of Korea
| | - Jung Hwa Seo
- Department of Materials Physics
- DONG-A University
- Busan 604-714
- Republic of Korea
| | - Bright Walker
- School of Energy and Chemical Engineering
- Ulsan National Institute of Science and Technology
- Ulsan
- Republic of Korea
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Sung HH, Choo SH, Ko M, Kang SJ, Chae MR, Kam SC, Han DH, So I, Lee SW. Increased expression of TRPC4 channels associated with erectile dysfunction in diabetes. Andrology 2014; 2:550-8. [PMID: 24782410 DOI: 10.1111/j.2047-2927.2014.00214.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [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: 11/13/2013] [Revised: 03/09/2014] [Accepted: 03/15/2014] [Indexed: 11/27/2022]
Abstract
In recent reports, an association between altered TRPC channel function and the development of various diabetic complications has drawn the attention of many investigators. The aim of this study was to investigate the expression of TRPC4 channels of corpus smooth muscle (CSM) cells in diabetes, and to evaluate the association between erectile dysfunction (ED) and altered TRPC4 channel function. The expression of TRPC4 in the penile tissue of human, normal and diabetic rat was investigated using RT-PCR, western blotting and immunohistochemistry (IHC). In vivo gene transfer of dominant negative (DN) TRPC4 into the CSM of rat was conducted. In vivo pelvic nerve stimulation was performed to measure erectile function. Expression of TRPC1, TRPC3, TRPC4 and TRPC6 in human and rat CSM tissues was confirmed by RT-PCR, western blot and IHC. In the diabetic rat, the expression levels of mRNA and protein of the TRPC4, and TRPC6 were significantly increased compared to control rats (p < 0.05). The change in TRPC4 expression in the diabetic rats was higher than those of the other TRPC subunits (p < 0.05). The IHC showed that only TRPC4 expression had a higher intensity in the diabetes compared to normal rats (p < 0.05). Gene transfection with TRPC4(DN) into the diabetic rats restored erectile function to levels similar to that of normal controls. Gene expression of TRPC4(DN) in CSM tissue was confirmed by RT-PCR 2 weeks after transfection. This study demonstrated that TRPC4 channel expression increased in the penile CSM cells of diabetic rats. The down-regulation of TRPC4 with DN form restored erectile function in the diabetic rats. The alteration of TRPC4 channel is one of pathophysiology of ED and could be a target for drug development for ED.
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Affiliation(s)
- H H Sung
- Department of Urology, Samsung Medical Center, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Seoul, South Korea
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Kim YS, Kang SJ, Kim JW, Cho HR, Moon SB, Kim KY, Lee HS, Han CH, Ku SK, Lee YJ. Effects of Polycan, a β-glucan, on experimental periodontitis and alveolar bone loss in Sprague-Dawley rats. J Periodontal Res 2012; 47:800-10. [PMID: 22780690 DOI: 10.1111/j.1600-0765.2012.01502.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND AND OBJECTIVE Polycan is a promising candidate for the treatment of periodontal disease. This study was undertaken to examine whether Polycan, a type of β-glucan, has a protective effect on ligature-induced experimental periodontitis and related alveolar bone loss in Sprague-Dawley rats. MATERIAL AND METHODS Polycan was orally administered, daily, for 10 d, at 21.25, 42.5 or 85 mg/kg, beginning 1 d after ligation. Changes in body weight and alveolar bone loss were monitored, and the anti-inflammatory effects of Polycan were determined by measuring the levels of myeloperoxidase (MPO), interleukin-1beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) in gingival tissue. We also evaluated inducible nitric oxide synthase (iNOS) activity and malondialdehyde (MDA) concentrations as a measure of the antioxidant effect. RESULTS Ligature placement led to a marked decrease in body weight, increased alveolar bone loss and increased concentrations of MPO, IL-1β, TNF-α and MDA, as well as increased iNOS activity and inflammatory cell infiltration and decreased collagen-fiber content. Histological examination revealed increases in the number and activity of osteoclast cells, decreases in alveolar bone volume and elevated percentages of osteclasts on the alveolar bone surface. Daily oral treatment with 42.5 or 85 mg/kg of Polycan for 10 d led to significant, dose-dependent inhibition of the effect of ligature placement. CONCLUSION Taken together, these results suggest that 10 d of oral treatment with Polycan effectively inhibits ligature placement-induced periodontitis and related alveolar bone loss via an antioxidant effect.
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Affiliation(s)
- Y S Kim
- Department of Dental Hygiene, Daegu Health College, Daegu, Korea
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Kang JH, Choi NK, Kang SJ, Yang SY, Ko HM, Jung JY, Kim MS, Koh JT, Kim WJ, Oh WM, Kim BY, Kim SH. Alendronate affects cartilage resorption by regulating vascular endothelial growth factor expression in rats. Anat Rec (Hoboken) 2010; 293:786-93. [PMID: 20432372 DOI: 10.1002/ar.21092] [Citation(s) in RCA: 8] [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] [Indexed: 11/11/2022]
Abstract
This study was performed to determine effects of alendronate on the tibial proximal epiphyseal cartilage undergoing endochondral ossification and the expression of vascular endothelial growth factor (VEGF) from the cartilage. Alendronate was injected subcutaneously every other day in postnatal Day 1 Sprague Dawley rats. The rats were sacrificed 3, 5, 7, and 10 days after the first injection. The effect of alendronate treatment for 10 days was demonstrated from the morphological change that the area of the secondary ossification center in the epiphysis was significantly smaller in the alendronate group than that in the control group (P < 0.05). Strong immunoreactivity to VEGF was observed in the hypertrophied chondrocytes and some proliferating chondrocytes in the epiphyseal cartilage at postnatal Day 5 and was decreased after the alendronate treatment for 5 days. Immunoreactivity was observed in not only hypertrophied cells but also the peripheral cartilaginous matrix adjacent to the vascular canals invading into the central portion of the cartilage at postnatal Day 7. This reactivity was also reduced considerably by the alendronate treatment for 7 days. The level of VEGF expression was reduced by the alendronate treatment at both the transcription and translation levels. However, the transcriptional level of the flt-1 and flk-1 receptors was relatively unaltered by the treatment. These results suggest that VEGF expression is required for vascular invasion into the developing cartilage and alendronate can affect its resorption by downregulating VEGF expression.
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Affiliation(s)
- J H Kang
- Dental Science Research Institute, Second Stage Brain Korea, School of Dentistry, Chonnam National University, Gwangju, South Korea
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Kim YK, Chin JH, Kang SJ, Jun IG, Song JG, Jeong SM, Park JY, Hwang GS. Association between central venous pressure and blood loss during hepatic resection in 984 living donors. Acta Anaesthesiol Scand 2009; 53:601-6. [PMID: 19419353 DOI: 10.1111/j.1399-6576.2009.01920.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
BACKGROUND Although low central venous pressure (CVP) anesthesia has been used to minimize blood loss during hepatectomy, the efficacy of this technique remains controversial. We therefore assessed the association between blood loss and CVP during hepatic resection, and examined significant determinants associated with intraoperative hemorrhage during hepatectomy in living donors. METHODS Between April 2004 and April 2008, 984 living donors who underwent a hepatic resection were assessed retrospectively. Univariate and multivariate analyses were performed to explore the relationships between intraoperative blood loss and several variables including CVP. RESULTS The mean intraoperative blood loss was 691.3 +/- 365.5 ml. Only four donors required packed red blood cell transfusions (mean, 1.5 U). The mean duration of hepatic resection was 92.1 +/- 26.3 min. The mean, maximum, and minimum values of CVP measured during hepatectomy were 4.6 +/- 1.7, 5.3 +/- 1.8, and 4.0 +/- 1.8 mmHg, respectively, and were not significantly correlated with intraoperative blood loss. On multivariate analysis, predictors of hemorrhage were liver fatty change, gender, and body weight, but none of the mean CVP, surgeons, anesthesiologists, anesthesia duration, resected liver volume, hepatectomy type, systolic blood pressure, heart rate, or body temperature were significant. CONCLUSIONS CVP during hepatic resection was not associated with intraoperative blood loss in living liver donors, suggesting that CVP may not be an important factor in predicting blood loss during hepatectomy in healthy subjects.
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Affiliation(s)
- Y K Kim
- Department of Anesthesiology and Pain Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
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Singh SR, Grossniklaus HE, Kang SJ, Edelhauser HF, Ambati BK, Kompella UB. Intravenous transferrin, RGD peptide and dual-targeted nanoparticles enhance anti-VEGF intraceptor gene delivery to laser-induced CNV. Gene Ther 2009; 16:645-59. [PMID: 19194480 DOI: 10.1038/gt.2008.185] [Citation(s) in RCA: 149] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Choroidal neovascularization (CNV) leads to loss of vision in age-related macular degeneration (AMD), the leading cause of blindness in adult population over 50 years old. In this study, we developed intravenously administered, nanoparticulate, targeted nonviral retinal gene delivery systems for the management of CNV. CNV was induced in Brown Norway rats using a 532 nm laser. We engineered transferrin, arginine-glycine-aspartic acid (RGD) peptide or dual-functionalized poly-(lactide-co-glycolide) nanoparticles to target delivery of anti-vascular endothelial growth factor (VEGF) intraceptor plasmid to CNV lesions. Anti-VEGF intraceptor is the only intracellularly acting VEGF inhibitory modality. The results of the study show that nanoparticles allow targeted delivery to the neovascular eye but not the control eye on intravenous administration. Functionalizing the nanoparticle surface with transferrin, a linear RGD peptide or both increased the retinal delivery of nanoparticles and subsequently the intraceptor gene expression in retinal vascular endothelial cells, photoreceptor outer segments and retinal pigment epithelial cells when compared to nonfunctionalized nanoparticles. Most significantly, the CNV areas were significantly smaller in rats treated with functionalized nanoparticles as compared to the ones treated with vehicle or nonfunctionalized nanoparticles. Thus, surface-functionalized nanoparticles allow targeted gene delivery to the neovascular eye on intravenous administration and inhibit the progression of laser-induced CNV in a rodent model.
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Affiliation(s)
- S R Singh
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, NE, USA
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Moon SY, Lee BH, Seo SW, Kang SJ, Na DL. Slow vertical saccades in the frontotemporal dementia with motor neuron disease. J Neurol 2008; 255:1337-43. [PMID: 18825435 DOI: 10.1007/s00415-008-0890-y] [Citation(s) in RCA: 10] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2007] [Revised: 12/10/2007] [Accepted: 02/01/2008] [Indexed: 02/02/2023]
Abstract
BACKGROUND Ocular motor abnormalities play an important role in differential diagnoses of Pick complex diseases. OBJECTIVES We evaluated how frequently supranuclear vertical saccadic impairment was observed in patients with frontotemporal dementia with motor neuron disease (FTD-MND). In addition, we tried to characterize their vertical saccadic abnormalities. MATERIALS AND METHODS Eleven patients with FTD-MND were recruited. Supranuclear vertical saccadic impairment on gross examination was defined as slow saccades with or without reduction in the final amplitude of the movement accompanied by intact oculocephalic reflex. We also recorded their saccades in 6 out of 11 patients using 2-dimensional videooculography (VOG). We measured the amplitude and peak velocity of each saccade. RESULTS On bedside examination, supranuclear vertical saccadic impairment was observed in 9 of 11 patients. One of the two remaining patients could not be evaluated due to poor cooperation and the other showed normal saccades. Five of nine patients with ocular abnormalities and one patient with normal saccade on gross examination underwent the VOG studies. The results showed that all the five patients with gross ocular abnormalities, compared with age-matched controls, had slowing of vertical saccades. Three out of five patients also showed slowing even in the large horizontal saccades. CONCLUSIONS Our results showed that slow vertical saccades are common in FTDMND. FTD-MND could be another disease that affects vertical gaze among Pick complex disease. Future pathologic studies are needed to confirm the involvement of the burst neurons in the dorsal midbrain in patients with FTDMND.
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Affiliation(s)
- S Y Moon
- Dept. of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Kangnam-ku, Seoul, 135-710, Korea
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Khan MA, Lee HJ, Lee WS, Kim HS, Ki KS, Hur TY, Suh GH, Kang SJ, Choi YJ. Structural growth, rumen development, and metabolic and immune responses of Holstein male calves fed milk through step-down and conventional methods. J Dairy Sci 2007; 90:3376-87. [PMID: 17582123 DOI: 10.3168/jds.2007-0104] [Citation(s) in RCA: 171] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Structural growth, feed consumption, rumen development, metabolic response, and immune response were studied in Holstein calves fed milk through either a conventional method or a step-down (STEP) method. In the conventional method, calves (n = 20) were fed colostrum and then milk at a rate of 10% of their BW for the entire period of 44 d. In the STEP method, calves (n = 20) were given colostrum and then milk at a rate of 20% of their BW for 23 d, which was reduced (between d 24 to 28) to 10% of their BW for the remaining 16 d. The calves on both methods were weaned gradually by diluting milk with water between d 45 and 49. After weaning, feed consumption, structural growth, and body weight gain were monitored until calves were 63 d of age. At d 63, twelve calves (6/treatment) were euthanized and rumen papillae length, papillae width, rumen wall thickness, and emptied forestomach weight were recorded. At wk 4, 7, and 9, ruminal contents were collected to enumerate rumen metabolites. The STEP-fed calves consumed a greater amount of milk than conventionally fed calves during the pre-STEP (d 1 to 28), post-STEP (d 29 to 49), and preweaning (d 1 to 49) periods. Consumption of starter and hay was greater during the pre-STEP period and lesser during the post-STEP and postweaning (d 50 to 63) periods in calves on the conventional method than on the STEP method. Body weight gain and structural growth measurements of calves were greater on the STEP method than on the conventional method. A hypophagic condition caused by greater milk consumption depressed solid feed intake of STEP-fed calves during the pre-STEP period, and a hyperphagic response caused by a reduced nutrient supply from milk triggered their consumption of solid feed during the post-STEP and postweaning periods. Ruminal pH and concentrations of ammonia, total volatile fatty acids, acetate, propionate, butyrate, and plasma beta-hydroxybutyrate were higher in calves on the STEP method and at weaning and postweaning (d 63) were lower in calves on the conventional method. Emptied weight of the forestomach, rumen wall thickness, papillae length, papillae width, and papillae concentration were higher in calves on the STEP method than in those on the conventional method. Blood glucose was lower, and blood urea nitrogen and beta-hydroxybutyrate at weaning and postweaning were higher in STEP-fed calves. Serum IgG, IgA, and triglycerides for 1, 2, and 3 wk of age were higher in calves on the STEP method than in those on the conventional method. In conclusion, greater feed consumption, BW gain, and structural growth, and a more metabolically and physically developed rumen were observed in calves on the STEP method than in those on the conventional method.
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Affiliation(s)
- M A Khan
- Dairy Cattle Research Division, National Livestock Research Institute, Cheonan, 330-880, Republic of Korea
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Kang SJ, Kocabas C, Kim HS, Cao Q, Meitl MA, Khang DY, Rogers JA. Printed multilayer superstructures of aligned single-walled carbon nanotubes for electronic applications. Nano Lett 2007; 7:3343-8. [PMID: 17935374 DOI: 10.1021/nl071596s] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
We developed means to form multilayer superstructures of large collections of single-walled carbon nanotubes (SWNTs) configured in horizontally aligned arrays, random networks, and complex geometries of arrays and networks on a wide range of substrates. The approach involves guided growth of SWNTs on crystalline and amorphous substrates followed by sequential, multiple step transfer of the resulting collections of tubes to target substrates, such as high-k thin dielectrics on silicon wafers, transparent plates of glass, cylindrical tubes and other curved surfaces, and thin, flexible sheets of plastic. Electrical measurements on dense, bilayer superstructures, including crossbars, random networks, and aligned arrays on networks of SWNTs reveal some important characteristics of representative systems. These and other layouts of SWNTs might find applications not only in electronics but also in areas such as optoelectronics, sensors, nanomechanical systems, and microfluidics.
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Affiliation(s)
- Seong Jun Kang
- Department of Materials Science and Engineering, University of Illinois, Urbana-Champaign, Illinois, USA
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Park JU, Hardy M, Kang SJ, Barton K, Adair K, Mukhopadhyay DK, Lee CY, Strano MS, Alleyne AG, Georgiadis JG, Ferreira PM, Rogers JA. High-resolution electrohydrodynamic jet printing. Nat Mater 2007; 6:782-9. [PMID: 17676047 DOI: 10.1038/nmat1974] [Citation(s) in RCA: 481] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2007] [Accepted: 06/21/2007] [Indexed: 05/16/2023]
Abstract
Efforts to adapt and extend graphic arts printing techniques for demanding device applications in electronics, biotechnology and microelectromechanical systems have grown rapidly in recent years. Here, we describe the use of electrohydrodynamically induced fluid flows through fine microcapillary nozzles for jet printing of patterns and functional devices with submicrometre resolution. Key aspects of the physics of this approach, which has some features in common with related but comparatively low-resolution techniques for graphic arts, are revealed through direct high-speed imaging of the droplet formation processes. Printing of complex patterns of inks, ranging from insulating and conducting polymers, to solution suspensions of silicon nanoparticles and rods, to single-walled carbon nanotubes, using integrated computer-controlled printer systems illustrates some of the capabilities. High-resolution printed metal interconnects, electrodes and probing pads for representative circuit patterns and functional transistors with critical dimensions as small as 1 mum demonstrate potential applications in printed electronics.
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Affiliation(s)
- Jang-Ung Park
- Department of Materials Science and Engineering, Beckman Institute, and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, 1304 West Green Street, Urbana, Illinois 61801, USA
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Kang SJ, Schmack I, Benson HE, Grossniklaus HE. Histopathological findings in postmortem eyes after photodynamic therapy for choroidal neovascularisation in age-related macular degeneration: report of two cases. Br J Ophthalmol 2007; 91:1602-6. [PMID: 17567659 PMCID: PMC2095496 DOI: 10.1136/bjo.2007.121830] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND To report the histopathological findings after photodynamic therapy (PDT) in eyes obtained postmortem with choroidal neovascularisation (CNV) secondary to age-related macular degeneration (AMD). METHODS Two eyes were obtained postmortem from two patients with CNV secondary to AMD. Both of the patients had been treated with PDT. Serial sections through the posterior poles were obtained and stained with haematoxylin-eosin, periodic acid-Schiff, Masson trichrome or phosphotungstic acid haematoxylin (PTAH). Two-dimensional reconstructions were prepared and compared with fluorescein angiograms. RESULTS The interval between PDT and death was 3 months and 17 months in each patient, respectively. Light-microscopic examination showed that CNV enveloped with retinal pigment epithelium (RPE) in both eyes. The average size of the CNV was 550 x 280 microm. One eye had combined (subRPE/subretinal) growth pattern CNV, and the other eye had both type I (subRPE) and combined growth pattern CNV. All specimens contained fibrous proliferation and patent vascular channels within the CNV, and there was no thrombus formation within the vascular channels. No apparent abnormalities in the choroid were observed by light microscopy. CONCLUSIONS Although involution with fibrous tissue proliferation occurred, PDT did not result in permanent occlusion of the vascular channels in the CNV. Our findings indicate that PDT may accelerate involution of CNV, thus limiting its size and preserving photoreceptors.
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Affiliation(s)
- S J Kang
- LF Montgomery Ophthalmic Pathology Laboratory, Emory Eye Center, 1365-B Clifton Road NE, Atlanta, GA 30322, USA.
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Kocabas C, Pimparkar N, Yesilyurt O, Kang SJ, Alam MA, Rogers JA. Experimental and theoretical studies of transport through large scale, partially aligned arrays of single-walled carbon nanotubes in thin film type transistors. Nano Lett 2007; 7:1195-202. [PMID: 17394371 DOI: 10.1021/nl062907m] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Gate-modulated transport through partially aligned films of single-walled carbon nanotubes (SWNTs) in thin film type transistor structures are studied experimentally and theoretically. Measurements are reported on SWNTs grown by chemical vapor deposition with systematically varying degrees of alignment and coverage in transistors with a range of channel lengths and orientations perpendicular and parallel to the direction of alignment. A first principles stick-percolation-based transport model provides a simple, yet quantitative framework to interpret the sometimes counterintuitive transport parameters measured in these devices. The results highlight, for example, the dramatic influence of small degrees of SWNT misalignment on transistor performance and imply that coverage and alignment are correlated phenomena and therefore should be simultaneously optimized. The transport characteristics reflect heterogeneity in the underlying anisotropic metal-semiconductor stick-percolating network and cannot be reproduced by classical transport models.
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Affiliation(s)
- C Kocabas
- Department of Physics, Beckman Institute, University of Illinois, Urbana--Champaign, IL, USA
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Kang SJ, Kim SH, Liu P, Jovel E, Towers GHN. Antibacterial activities of some mosses including Hylocomium splendens from South Western British Columbia. Fitoterapia 2007; 78:373-6. [PMID: 17553633 DOI: 10.1016/j.fitote.2007.03.008] [Citation(s) in RCA: 10] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2006] [Accepted: 03/05/2007] [Indexed: 11/17/2022]
Abstract
The antibacterial activity of methanol extracts of ten moss species and fractions prepared from 80% methanol extract of Hylocomium splendens were evaluated by disk diffusion method. Nine moss species showed antibacterial activity against Gram (+) bacteria, in particular H. splendens and its ethyl acetate fractions showed stronger activity. Enhancement of antibacterial activity against Staphylococci by UV-A light irradiation was demonstrated in the extracts of Bartramia pomiformis, Ceratodon purpureus and Neckera douglasii.
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Affiliation(s)
- S J Kang
- Korea Food and Drug Administration, Jinheungno, Seoul, 122-704, Republic of Korea.
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Tomkinson GR, Olds TS, Kang SJ, Kim DY. Secular Trends in the Aerobic Fitness Test Performance and Body Mass Index of Korean Children and Adolescents (1968 - 2000). Int J Sports Med 2007; 28:314-20. [PMID: 17024618 DOI: 10.1055/s-2006-924357] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
There is increasing evidence that the aerobic fitness performance of children is declining, at least in developed countries. To see if there was evidence of similar trends in a non-Western country, this study analysed data on 6-18-year-old Koreans tested between 1968 and 2000 using distance runs ranging from 600 to 1200 m. All existing data on the results of children's aerobic fitness tests in Korea were collated. In addition to six individual studies, very large datasets were available from the Korean Ministries of Education, and the Ministry of Culture and Tourism. Data on a total of 22,127,265 6-18-year-old children were available in the form of group means and standard deviations. Data were collated for each age x sex x test group, and performances were expressed as percentages of the fitted values for the year 1992 to standardise across tests, ages and sexes. All age x sex x test groups were then combined, and curves were fitted using weighted regression. A two-linear segment model best described the pattern of change (r = 0.83, p < 0.001). There was a relatively slow decline (0.26 % per year) in the aerobic performance of Korean children between 1968 and 1984. After 1984, however, there was a steep decline in performance, averaging 0.80 % per year. The rate of decline was greater in boys, younger children and children from outside the capital Seoul. Changes in running performance showed a similar pattern to changes in estimated body mass index. Compared to other countries, there has been a sharp decline in Korean children's performance on tests of aerobic fitness, which has been concurrent with increases in estimated body mass index.
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Affiliation(s)
- G R Tomkinson
- Centre for Applied Anthropometry, School of Health Sciences, University of South Australia, Adelaide, Australia.
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Kang SJ, Kocabas C, Ozel T, Shim M, Pimparkar N, Alam MA, Rotkin SV, Rogers JA. High-performance electronics using dense, perfectly aligned arrays of single-walled carbon nanotubes. Nat Nanotechnol 2007; 2:230-6. [PMID: 18654268 DOI: 10.1038/nnano.2007.77] [Citation(s) in RCA: 385] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2006] [Accepted: 02/23/2007] [Indexed: 05/17/2023]
Abstract
Single-walled carbon nanotubes (SWNTs) have many exceptional electronic properties. Realizing the full potential of SWNTs in realistic electronic systems requires a scalable approach to device and circuit integration. We report the use of dense, perfectly aligned arrays of long, perfectly linear SWNTs as an effective thin-film semiconductor suitable for integration into transistors and other classes of electronic devices. The large number of SWNTs enable excellent device-level performance characteristics and good device-to-device uniformity, even with SWNTs that are electronically heterogeneous. Measurements on p- and n-channel transistors that involve as many as approximately 2,100 SWNTs reveal device-level mobilities and scaled transconductances approaching approximately 1,000 cm(2) V(-1) s(-1) and approximately 3,000 S m(-1), respectively, and with current outputs of up to approximately 1 A in devices that use interdigitated electrodes. PMOS and CMOS logic gates and mechanically flexible transistors on plastic provide examples of devices that can be formed with this approach. Collectively, these results may represent a route to large-scale integrated nanotube electronics.
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Affiliation(s)
- Seong Jun Kang
- Department of Materials Science and Engineering, University of Illinois at Urbana Champaign, Urbana, Illinois 61801, USA
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Seo JH, Kim CY, Kang SJ, Yoo KH, Whang CN, Moewes A, Chang GS. Electronic structure of NPB and BCP molecules probed by x-ray emission spectroscopy. J Chem Phys 2007; 126:064706. [PMID: 17313237 DOI: 10.1063/1.2464086] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Soft x-ray absorption and emission spectroscopies have been employed to investigate the electronic structure and chemical bonding of two prototypical molecules, N,N(')-bis-(1-naphthyl)-N,N(')-diphenyl-1,1(')-biphenyl-4,4(')-diamine (NPB) and bathocuproine (BCP), which are frequently chosen because of their hole-transporting and hole-blocking properties, respectively. The resulting resonant C Kalpha x-ray emission spectra of these materials reveal different spectral features depending on the resonant excitation energy. According to the N absorption and emission spectra, the contribution of N atoms to the highest occupied and lowest unoccupied molecular orbitals is different for in NPB and in BCP. Detailed knowledge of these materials will allow tailoring charge transport properties of organic devices in order to develop high performance organic light-emitting diodes and photovoltaic cells.
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Affiliation(s)
- J H Seo
- Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749, Korea
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Ahn JH, Kim HS, Lee KJ, Jeon S, Kang SJ, Sun Y, Nuzzo RG, Rogers JA. Heterogeneous three-dimensional electronics by use of printed semiconductor nanomaterials. Science 2006; 314:1754-7. [PMID: 17170298 DOI: 10.1126/science.1132394] [Citation(s) in RCA: 290] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
We developed a simple approach to combine broad classes of dissimilar materials into heterogeneously integrated electronic systems with two- or three-dimensional layouts. The process begins with the synthesis of different semiconductor nanomaterials, such as single-walled carbon nanotubes and single-crystal micro- and nanoscale wires and ribbons of gallium nitride, silicon, and gallium arsenide on separate substrates. Repeated application of an additive, transfer printing process that uses soft stamps with these substrates as donors, followed by device and interconnect formation, yields high-performance heterogeneously integrated electronics that incorporate any combination of semiconductor nanomaterials on rigid or flexible device substrates. This versatile methodology can produce a wide range of unusual electronic systems that would be impossible to achieve with other techniques.
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Affiliation(s)
- Jong-Hyun Ahn
- Department of Materials Science and Engineering, University of Illinois, Urbana-Champaign, IL 61801, USA
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Han SA, Chun H, Park CM, Kang SJ, Kim SH, Sohn D, Yun SH, Lee WY. Prognostic Significance of β-catenin in Colorectal Cancer with Liver Metastasis. Clin Oncol (R Coll Radiol) 2006; 18:761-7. [PMID: 17168211 DOI: 10.1016/j.clon.2006.08.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
AIMS A decreased expression of beta-catenin has been known to be associated with tumour metastasis. The prognostic value of beta-catenin expression in colorectal cancer (CRC) patients with liver metastasis was evaluated. MATERIALS AND METHODS Seventy patients who underwent curative resection for CRC with liver metastasis were included. Tissue samples from normal colon mucosa, primary CRC and metastatic liver lesions were prepared in tissue microarrays, and were stained by immunohistochemistry with beta-catenin antibody. The beta-catenin expression of primary CRC tissues and metastatic liver tissues was analysed. RESULTS A high expression of beta-catenin (score > 6) was observed in 42.0% and 21.9% of primary colorectal tissues and metastatic liver tissues, respectively. The beta-catenin expression in metastatic liver tissues was significantly lower than in primary CRC tissues (P = 0.022). The patients were classified into two groups according to the difference in the beta-catenin expression score between the primary CRC and the liver metastasis. Group A was defined as patients showing a remarkably decreased expression of beta-catenin in their metastatic liver tissue and group B was defined as patients showing a maintained or increased beta-catenin expression in their metastatic liver tissue in comparison with their primary CRC. The overall survival and disease-free survival rates were better in group B than in group A, and this was statistically significant (P = 0.02, P = 0.002). CONCLUSION The decreased expression of beta-catenin in a metastatic liver lesion may be a poor prognostic marker in CRC with liver metastasis and further investigation is necessary.
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Affiliation(s)
- S A Han
- Department of Surgery, Sungkyunkwan University School of Medicine, Samsung Medical Center, Seoul, South Korea
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Abstract
Frontotemporal dementia (FTD) often coexists with motor neuron disease (MND). To characterize glucose hypometabolism in patients with FTD with MND (FTD/MND), the authors compared the glucose metabolism of 8 patients with FTD/MND with that of 29 patients with FTD. All of the patients with FTD/MND showed glucose hypometabolism only in the frontal area, whereas most patients with FTD had hypometabolism in the frontal and temporal areas. FTD/MND also showed a more symmetric pattern of glucose hypometabolism than FTD.
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Affiliation(s)
- Y Jeong
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
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Jeong Y, Song YM, Chung PW, Kim EJ, Kang SJ, Kim JM, Cho SS, Kim SE, Byun HS, Na DL. Correlation of ventricular asymmetry with metabolic asymmetry in frontotemporal dementia. J Neuroradiol 2005; 32:247-54. [PMID: 16237363 DOI: 10.1016/s0150-9861(05)83145-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND AND PURPOSE The clinical presentation of frontotemporal dementia (FTD) is often asymmetrical in terms of both its clinical features and atrophy on MRI. Asymmetry in the lateral ventricle size on structural neuroimaging in FTD patients may have clinical significance. However, this has not been systematically investigated yet. This study compares the ventricular asymmetry seen on MRI with that of the asymmetric glucose metabolism using FDG-PET in patients with FTD. METHODS Nineteen FTD patients who underwent both brain MRI and FDG-PET were retrospectively selected. As control groups, 23 and 11 age and sex-matched healthy normal subjects underwent either brain MRI or FDG-PET, respectively. The ventricular asymmetry index (VAI) was obtained in two ways: by visual rating (VAI-V) and by measuring the lateral ventricular volumes (VAI-ROI). The hemispheric asymmetry of the glucose metabolism on FDG-PET (MAI) was assessed in three ways: 1) by visual rating (MAI-V), 2) by counting the FDG activity of each hemisphere on normalized and smoothed PET images (MAI-ROI) and 3) by counting the number of voxels with significant hypometabolism based on statistical parametric mapping results (MAI-SPM). RESULTS The VAIs on MRI (VAI-V and VAI-ROI) were highly correlated, as were the MAIs (MAI-V, MAI-ROI, and MAI-SPM) on FDG-PET. More importantly, the VAIs on MRI and the MAIs on FDG-PET showed high correlation. CONCLUSIONS Ventricular asymmetry in FTD patients was common (78.9%) and there was a high correlation between the ventricular structural asymmetry and the hemispheric metabolic asymmetry. Therefore, it would be reasonable to interpret that the hemisphere with larger ventricle on MRI in FTD patients is undergoing a more active degenerative process.
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Affiliation(s)
- Y Jeong
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 ILwon-dong, Kangnam-ku, Seoul, 135-710 Korea
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