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Huynh T, Ngo TD, Choi H, Choi M, Lee W, Nguyen TD, Tran TT, Lee K, Hwang JY, Kim J, Yoo WJ. Analysis of p-Type Doping in Graphene Induced by Monolayer-Oxidized TMDs. ACS Appl Mater Interfaces 2024; 16:3694-3702. [PMID: 38214703 DOI: 10.1021/acsami.3c16229] [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: 01/13/2024]
Abstract
Doping is one of the most difficult technological challenges for realizing reliable two-dimensional (2D) material-based semiconductor devices, arising from their ultrathinness. Here, we systematically investigate the impact of different types of nonstoichiometric solid MOx (M are W or Mo) dopants obtained by oxidizing transition metal dichalcogenides (TMDs: WSe2 or MoS2) formed on graphene FETs, which results in p-type doping along with disorders. From the results obtained in this study, we were able to suggest an analytical technique to optimize the optimal UV-ozone (UVO) treatment to achieve high p-type doping concentration in graphene FETs (∼2.5 × 1013 cm-2 in this study) without generating defects, mainly by analyzing the time dependency of D and D' peaks measured by Raman spectroscopy. Furthermore, an analysis of the structure of graphene sheets using TEM indicates that WOx plays a better protective role in graphene, compared to MoOx, suggesting that WOx is more effective for preventing the degradation of graphene during UVO treatment. To enhance the practical application aspect of our work, we have fabricated a graphene photodetector by selectively doping the graphene through oxidized TMDs, creating a p-n junction, which resulted in improved photoresponsivity compared to the intrinsic graphene device. Our results offer a practical guideline for the utilization of surface charge transfer doping of graphene toward CMOS applications.
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Affiliation(s)
- Tuyen Huynh
- SKKU Advanced Institute of Nano Technology, Sungkyunkwan University, Suwon, Gyeonggi-do 16419, Korea
| | - Tien Dat Ngo
- SKKU Advanced Institute of Nano Technology, Sungkyunkwan University, Suwon, Gyeonggi-do 16419, Korea
| | - Hyungyu Choi
- SKKU Advanced Institute of Nano Technology, Sungkyunkwan University, Suwon, Gyeonggi-do 16419, Korea
| | - Minsup Choi
- Department of Materials Science and Engineering, Chungnam National University, Daejeon 34134, Korea
| | - Wonki Lee
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology (KIST), Wanju-gun, Jeolabuk-do 55324, Korea
| | - Tuan Dung Nguyen
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Suwon, Gyeonggi-do 16419, Korea
| | - Trang Thu Tran
- Department of Energy Science, Sungkyunkwan University, Suwon, Gyeonggi-do 16419, Korea
| | - Kwangro Lee
- SKKU Advanced Institute of Nano Technology, Sungkyunkwan University, Suwon, Gyeonggi-do 16419, Korea
| | - Jun Yeon Hwang
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology (KIST), Wanju-gun, Jeolabuk-do 55324, Korea
| | - Jeongyong Kim
- Department of Energy Science, Sungkyunkwan University, Suwon, Gyeonggi-do 16419, Korea
| | - Won Jong Yoo
- SKKU Advanced Institute of Nano Technology, Sungkyunkwan University, Suwon, Gyeonggi-do 16419, Korea
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2
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Nand KN, Jordan TB, Yuan X, Basore DA, Zagorevski D, Clarke C, Werner G, Hwang JY, Wang H, Chung JJ, McKenna A, Jarvis MD, Singh G, Bystroff C. Bacterial production of recombinant contraceptive vaccine antigen from CatSper displayed on a human papilloma virus-like particle. Vaccine 2023:S0264-410X(23)01114-3. [PMID: 37833124 DOI: 10.1016/j.vaccine.2023.09.044] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 09/19/2023] [Accepted: 09/20/2023] [Indexed: 10/15/2023]
Abstract
CatSper is a voltage dependent calcium ion channel present in the principal piece of sperm tail. It plays a crucial role in sperm hyperactivated motility and so in fertilization. Extracellular loops of mouse sperm CatSper were used to develop a vaccine to achieve protection from pregnancy. These loops were inserted at one of the three hypervariable regions of Human Papilloma Virus (HPV) capsid protein (L1). Recombinant vaccines were expressed in E.coli as inclusion body (IB), purified, refolded and assembled into virus-like particles (VLP) in vitro, and adsorbed on alum. Four vaccine candidates were tested in Balb/C mice. All the constructs proved immunogenic, one showed contraceptive efficacy. This recombinant contraceptive vaccine is a non-hormonal intervention and is expected to give long-acting protection from undesired pregnancies.
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Affiliation(s)
- K N Nand
- Dept of Biological Sciences, Rensselaer Polytechnic Institute, Troy NY, United States
| | - T B Jordan
- Dept of Biological Sciences, Rensselaer Polytechnic Institute, Troy NY, United States
| | - X Yuan
- Dept of Biological Sciences, Rensselaer Polytechnic Institute, Troy NY, United States
| | - D A Basore
- Dept of Biological Sciences, Rensselaer Polytechnic Institute, Troy NY, United States; Department of Health and Natural Science, Mercy College, Dobbs Ferry, NY, United States
| | - D Zagorevski
- Dept of Biological Sciences, Rensselaer Polytechnic Institute, Troy NY, United States
| | - C Clarke
- Dept of Biological Sciences, Rensselaer Polytechnic Institute, Troy NY, United States
| | - G Werner
- Dept of Biological Sciences, Rensselaer Polytechnic Institute, Troy NY, United States
| | - J Y Hwang
- Dept of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT, United States
| | - H Wang
- Dept of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT, United States
| | - J-J Chung
- Dept of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT, United States; Department of Gynecology and Obstetrics, Yale University School of Medicine, New Haven, CT, United States
| | - A McKenna
- Bioresearch Core, Rensselaer Polytechnic Institute, Troy, NY, United States
| | - M D Jarvis
- Bioresearch Core, Rensselaer Polytechnic Institute, Troy, NY, United States
| | - G Singh
- Bioresearch Core, Rensselaer Polytechnic Institute, Troy, NY, United States
| | - C Bystroff
- Dept of Biological Sciences, Rensselaer Polytechnic Institute, Troy NY, United States.
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3
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Lee JW, Kim SS, Lee MW, Hwang JY, Moon SY. High-Strength Epoxy Nanocomposites Reinforced with Photochemically Treated CNTs. ACS Omega 2023; 8:19789-19797. [PMID: 37305311 PMCID: PMC10249089 DOI: 10.1021/acsomega.3c01537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 05/09/2023] [Indexed: 06/13/2023]
Abstract
A carbon nanotube (CNT)/epoxy nanocomposite was prepared using a photochemical surface modification process of CNTs. The vacuum ultraviolet (VUV)-excimer lamp treatment created reactive sites on the CNT surface. Increasing the irradiation time increased the oxygen functional groups and changed the oxygen bonding state such as C=O, C-O, and -COOH. By the VUV-excimer irradiation on CNTs, the epoxy infiltrated well between the CNT bundles and formed a strong chemical bond between CNT and epoxy. The tensile strength and elastic modulus of the nanocomposites with VUV-excimer irradiated sample during 30 min (R30) were found to increase by 30 and 68% compared to using pristine CNT, respectively. R30 was not pulled out and remained embedded in the matrix until the fracture occurred. The VUV-excimer irradiation is an effective surface modification and functionalization method for improving the mechanical properties of CNT nanocomposite materials.
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Affiliation(s)
- Jae Won Lee
- Institute
of Advanced Composite Materials, Korea Institute
of Science and Technology (KIST), Chudong-ro 92, Bongdong-eup, Wanju-gun, Jeonbuk 55324, Republic of Korea
- Department
of Materials Science and Chemical Engineering, Hanyang University, Ansan-si, Gyeongi-do 15588, Republic of Korea
| | - Sung-Soo Kim
- Institute
of Advanced Composite Materials, Korea Institute
of Science and Technology (KIST), Chudong-ro 92, Bongdong-eup, Wanju-gun, Jeonbuk 55324, Republic of Korea
| | - Min Wook Lee
- Institute
of Advanced Composite Materials, Korea Institute
of Science and Technology (KIST), Chudong-ro 92, Bongdong-eup, Wanju-gun, Jeonbuk 55324, Republic of Korea
| | - Jun Yeon Hwang
- Institute
of Advanced Composite Materials, Korea Institute
of Science and Technology (KIST), Chudong-ro 92, Bongdong-eup, Wanju-gun, Jeonbuk 55324, Republic of Korea
| | - Sook Young Moon
- Institute
of Advanced Composite Materials, Korea Institute
of Science and Technology (KIST), Chudong-ro 92, Bongdong-eup, Wanju-gun, Jeonbuk 55324, Republic of Korea
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4
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Cho HY, Lee K, Kong HJ, Yang HL, Jung CW, Park HP, Hwang JY, Lee HC. Deep-learning model associating lateral cervical radiographic features with Cormack-Lehane grade 3 or 4 glottic view. Anaesthesia 2023; 78:64-72. [PMID: 36198200 DOI: 10.1111/anae.15874] [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] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/31/2022] [Indexed: 12/13/2022]
Abstract
Unanticipated difficult laryngoscopy is associated with serious airway-related complications. We aimed to develop and test a convolutional neural network-based deep-learning model that uses lateral cervical spine radiographs to predict Cormack-Lehane grade 3 or 4 direct laryngoscopy views of the glottis. We analysed the radiographs of 5939 thyroid surgery patients at our hospital, 253 (4%) of whom had grade 3 or 4 glottic views. We used 10 randomly sampled datasets to train a model. We compared the new model with six similar models (VGG, ResNet, Xception, ResNext, DenseNet and SENet). The Brier score (95%CI) of the new model, 0.023 (0.021-0.025), was lower ('better') than the other models: VGG, 0.034 (0.034-0.035); ResNet, 0.033 (0.033-0.035); Xception, 0.032 (0.031-0.033); ResNext, 0.033 (0.032-0.033); DenseNet, 0.030 (0.029-0.032); SENet, 0.031 (0.029-0.032), all p < 0.001. We calculated mean (95%CI) of the new model for: R2 , 0.428 (0.388-0.468); mean squared error, 0.023 (0.021-0.025); mean absolute error, 0.048 (0.046-0.049); balanced accuracy, 0.713 (0.684-0.742); and area under the receiver operating characteristic curve, 0.965 (0.962-0.969). Radiographic features around the hyoid bone, pharynx and cervical spine were associated with grade 3 and 4 glottic views.
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Affiliation(s)
- H-Y Cho
- Department of Anaesthesiology and Pain Medicine, Seoul National University Hospital, Seoul, Republic of Korea.,Department of Anaesthesiology and Pain Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - K Lee
- Department of Electrical Engineering and Computer Science, Daegu Gyeongbuk Institute of Science and Technology, Daegu, Republic of Korea.,Medical Big data Research Center, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - H-J Kong
- Transdisciplinary Department of Medicine and Advanced Technology, Seoul National University Hospital, Seoul, Republic of Korea.,Department of Biomedical Engineering, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - H-L Yang
- Department of Anaesthesiology and Pain Medicine, Seoul National University Hospital, Seoul, Republic of Korea.,Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
| | - C-W Jung
- Department of Anaesthesiology and Pain Medicine, Seoul National University Hospital, Seoul, Republic of Korea.,Department of Anaesthesiology and Pain Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - H-P Park
- Department of Anaesthesiology and Pain Medicine, Seoul National University Hospital, Seoul, Republic of Korea.,Department of Anaesthesiology and Pain Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - J Y Hwang
- Department of Electrical Engineering and Computer Science, Daegu Gyeongbuk Institute of Science and Technology, Daegu, Republic of Korea.,Department of Interdisciplinary Studies of Artificial Intelligence, Daegu Gyeongbuk Institute of Science and Technology, Daegu, Republic of Korea
| | - H-C Lee
- Department of Anaesthesiology and Pain Medicine, Seoul National University Hospital, Seoul, Republic of Korea.,Department of Anaesthesiology and Pain Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
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Song HG, Ahn JH, Koh JS, Bae JS, Park YW, Hwang SJ, Hwang JY, Jeong YH. Prognostic implication of residual inflammatory risk according to disease status in patients treated with percutaneous coronary intervention. Eur Heart J 2022. [DOI: 10.1093/eurheartj/ehac544.1289] [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: 11/13/2022] Open
Abstract
Abstract
Background
Compared with stable angina, acute myocardial infarction (AMI) phenotype is related with the elevated inflammatory activity. However, time-dependent change of inflammatory level and its prognostic implication has not been fully understood according to the disease entity.
Methods
We enrolled total 4,263 patients who underwent percutaneous coronary intervention (PCI) with serial measurement of high-sensitivity C-reactive protein (hsCRP) at on-admission and 1-month post-PCI. The risks of MACE (a composite of death, MI or stroke), and major bleeding were evaluated up to 4 years after procedure.
Results
Compared with the non-AMI group (n=1,887), the AMI group (n=2,376) showed the significant decrease of hs-CRP during 1 month (∇0.5 vs. ∇0.1 mg/L; P<0.001). However, 1-month hs-CRP value still was higher in the AMI group than in the non-AMI group (median: 1.0 vs. 0.9 mg/L; P=0.001). During 1-month follow-up, high vs. low inflammatory risk (upper vs. lower tertile of hs-CRP) was significantly associated with increased rate of MACE in the AMI group (HR: 7.66; 95% CI: 2.29–25.59; P<0.001), but not in the non-AMI group (HR: 0.74; 95% CI: 0.12–4.40; P=0.736). From 1-month to 4-years, patients with high inflammatory risk showed the greater rate of MACE compared to those with low inflammatory risk, in both the AMI (HR: 2.40; 95% CI: 1.73–3.45; P<0.001) and non-AMI (HR: 2.67; 95% CI: 1.80–3.94; P<0.001) groups.
Conclusion
In PCI-treated patients, patients presented with AMI showed the greater values of inflammatory activity and its prognostic implication during the early phase, but combined inflammatory risk appeared similar across the disease entity during the late phase. This result may support that clinical benefit of post-PCI anti-inflammatory treatment would be constant regardless of the disease entity during the stabilized phase.
Funding Acknowledgement
Type of funding sources: None.
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Affiliation(s)
- H G Song
- Department of Cardiology, Heart-Brain Hospital, Chung-Ang University Gwang-Myeong Medical Center , Gwang-Myeong , Korea (Republic of)
| | - J H Ahn
- Cardiovascular Center, Gyeongsang National University Changwon Hospital , Changwon , Korea (Republic of)
| | - J S Koh
- Cardiovascular Center, Gyeongsang National University Hospital , Jin-Ju , Korea (Republic of)
| | - J S Bae
- Cardiovascular Center, Gyeongsang National University Changwon Hospital , Changwon , Korea (Republic of)
| | - Y W Park
- Cardiovascular Center, Gyeongsang National University Changwon Hospital , Changwon , Korea (Republic of)
| | - S J Hwang
- Cardiovascular Center, Gyeongsang National University Hospital , Jin-Ju , Korea (Republic of)
| | - J Y Hwang
- Cardiovascular Center, Gyeongsang National University Hospital , Jin-Ju , Korea (Republic of)
| | - Y H Jeong
- Department of Cardiology, Heart-Brain Hospital, Chung-Ang University Gwang-Myeong Medical Center , Gwang-Myeong , Korea (Republic of)
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6
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Lee G, Oh Y, Nam JT, Ji S, Jang AR, Jeong DW, Kang M, Lee SS, Chae S, Cho D, Hwang JY, Lee K, Lee JO. Multifunctional-high resolution imaging plate based on hydrophilic graphene for digital pathology. Nanotechnology 2022; 33:505101. [PMID: 36095982 DOI: 10.1088/1361-6528/ac9143] [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] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 09/12/2022] [Indexed: 06/15/2023]
Abstract
In the present study, we showed that hydrophilic graphene can serve as an ideal imaging plate for biological specimens. Graphene being a single-atom-thick semi-metal with low secondary electron emission, array tomography analysis of serial sections of biological specimens on a graphene substrate showed excellent image quality with improvedz-axis resolution, without including any conductive surface coatings. However, the hydrophobic nature of graphene makes the placement of biological specimens difficult; graphene functionalized with polydimethylsiloxane oligomer was fabricated using a simple soft lithography technique and then processed with oxygen plasma to provide hydrophilic graphene with minimal damage to graphene. High-quality scanning electron microscopy images of biological specimens free from charging effects or distortion were obtained, and the optical transparency of graphene enabled fluorescence imaging of the specimen; high-resolution correlated electron and light microscopy analysis of the specimen became possible with the hydrophilic graphene plate.
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Affiliation(s)
- Geonhee Lee
- Advanced Materials Division, Korea Research Institute of Chemical Technology, Gajeongro 141, Daejeon, Republic of Korea
| | - Yuna Oh
- Korea Institute of Science and Technology, 5. Hwarang-ro 14-gil, Seongbuk-gu, Seoul, Republic of Korea
| | - Jung Tae Nam
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology, Jeonbuk, 55324, Republic of Korea
| | - Seulgi Ji
- Advanced Materials Division, Korea Research Institute of Chemical Technology, Gajeongro 141, Daejeon, Republic of Korea
| | - A-Rang Jang
- Division of Electrical, Electronic and Control Engineering, Kongju National University, Cheonan 31080, Republic of Korea
| | - Du Won Jeong
- Advanced Materials Division, Korea Research Institute of Chemical Technology, Gajeongro 141, Daejeon, Republic of Korea
| | - MinSoung Kang
- Advanced Materials Division, Korea Research Institute of Chemical Technology, Gajeongro 141, Daejeon, Republic of Korea
| | - Sun Sook Lee
- Advanced Materials Division, Korea Research Institute of Chemical Technology, Gajeongro 141, Daejeon, Republic of Korea
| | - Soosang Chae
- Department of Nanostructured Materials, Leibniz Institute of Polymer Research Dresden, D-01069, Dresden, Germany
| | - Donghwi Cho
- Advanced Materials Division, Korea Research Institute of Chemical Technology, Gajeongro 141, Daejeon, Republic of Korea
| | - Jun Yeon Hwang
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology, Jeonbuk, 55324, Republic of Korea
| | - Kyungeun Lee
- Korea Institute of Science and Technology, 5. Hwarang-ro 14-gil, Seongbuk-gu, Seoul, Republic of Korea
| | - Jeong-O Lee
- Advanced Materials Division, Korea Research Institute of Chemical Technology, Gajeongro 141, Daejeon, Republic of Korea
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7
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Kim SG, Heo SJ, Kim J, Kim SO, Lee D, Kim M, Kim ND, Kim D, Hwang JY, Chae HG, Ku B. Ultrastrong Hybrid Fibers with Tunable Macromolecular Interfaces of Graphene Oxide and Carbon Nanotube for Multifunctional Applications. Adv Sci (Weinh) 2022; 9:e2203008. [PMID: 35988149 PMCID: PMC9561868 DOI: 10.1002/advs.202203008] [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] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Revised: 07/20/2022] [Indexed: 06/15/2023]
Abstract
Individual carbon nanotubes (CNT) and graphene have unique mechanical and electrical properties; however, the properties of their macroscopic assemblies have not met expectations because of limited physical dimensions, the limited degree of dispersion of the components, and various structural defects. Here, a state-of-the-art assembly for a novel type of hybrid fiber possessing the properties required for a wide variety of multifunctional applications is presented. A simple and effective multidimensional nanostructure of CNT and graphene oxide (GO) assembled by solution processing improves the interfacial utilization of the components. Flexible GOs are effectively intercalated between nanotubes along the shape of CNTs, which reduces voids, enhances orientation, and maximizes the contact between elements. The microstructure is finely controlled by the elements content ratio and dimensions, and an optimal balance improves the mechanical properties. The hybrid fibers simultaneously exhibit exceptional strength (6.05 GPa), modulus (422 GPa), toughness (76.8 J g-1 ), electrical conductivity (8.43 MS m-1 ), and knot strength efficiency (92%). Furthermore, surface and electrochemical properties are significantly improved by tuning the GO content, further expanding the scope of applications. These hybrid fibers are expected to offer a strategy for overcoming the limitations of existing fibers in meeting the requirements for applications in the fiber industry.
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Affiliation(s)
- Seo Gyun Kim
- Institute of Advanced Composite MaterialsKorea Institute of Science and Technology (KIST)Wanju55324Republic of Korea
| | - So Jeong Heo
- Institute of Advanced Composite MaterialsKorea Institute of Science and Technology (KIST)Wanju55324Republic of Korea
- Department of Materials Science and EngineeringUlsan National Institute of Science and Technology (UNIST)Ulsan44919Republic of Korea
| | - Jeong‐Gil Kim
- Institute of Advanced Composite MaterialsKorea Institute of Science and Technology (KIST)Wanju55324Republic of Korea
- Department of Chemical and Biomolecular EngineeringKorea Advanced Institute of Science and Technology (KAIST)Daejeon34141Republic of Korea
| | - Sang One Kim
- Institute of Advanced Composite MaterialsKorea Institute of Science and Technology (KIST)Wanju55324Republic of Korea
- Department of Carbon Materials and Fiber EngineeringJeonbuk National UniversityJeonju54896Republic of Korea
| | - Dongju Lee
- Institute of Advanced Composite MaterialsKorea Institute of Science and Technology (KIST)Wanju55324Republic of Korea
- Department of Applied BioengineeringGraduate School of Convergence Science and TechnologySeoul National UniversitySuwon16229Republic of Korea
| | - Minkook Kim
- Institute of Advanced Composite MaterialsKorea Institute of Science and Technology (KIST)Wanju55324Republic of Korea
| | - Nam Dong Kim
- Institute of Advanced Composite MaterialsKorea Institute of Science and Technology (KIST)Wanju55324Republic of Korea
| | - Dae‐Yoon Kim
- Institute of Advanced Composite MaterialsKorea Institute of Science and Technology (KIST)Wanju55324Republic of Korea
| | - Jun Yeon Hwang
- Institute of Advanced Composite MaterialsKorea Institute of Science and Technology (KIST)Wanju55324Republic of Korea
| | - Han Gi Chae
- Department of Materials Science and EngineeringUlsan National Institute of Science and Technology (UNIST)Ulsan44919Republic of Korea
| | - Bon‐Cheol Ku
- Institute of Advanced Composite MaterialsKorea Institute of Science and Technology (KIST)Wanju55324Republic of Korea
- Department of Nano ConvergenceJeonbuk National UniversityJeonju54896Republic of Korea
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8
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Lee D, Kim SG, Hong S, Madrona C, Oh Y, Park M, Komatsu N, Taylor LW, Chung B, Kim J, Hwang JY, Yu J, Lee DS, Jeong HS, You NH, Kim ND, Kim DY, Lee HS, Lee KH, Kono J, Wehmeyer G, Pasquali M, Vilatela JJ, Ryu S, Ku BC. Ultrahigh strength, modulus, and conductivity of graphitic fibers by macromolecular coalescence. Sci Adv 2022; 8:eabn0939. [PMID: 35452295 PMCID: PMC9032978 DOI: 10.1126/sciadv.abn0939] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 03/07/2022] [Indexed: 05/26/2023]
Abstract
Theoretical considerations suggest that the strength of carbon nanotube (CNT) fibers be exceptional; however, their mechanical performance values are much lower than the theoretical values. To achieve macroscopic fibers with ultrahigh performance, we developed a method to form multidimensional nanostructures by coalescence of individual nanotubes. The highly aligned wet-spun fibers of single- or double-walled nanotube bundles were graphitized to induce nanotube collapse and multi-inner walled structures. These advanced nanostructures formed a network of interconnected, close-packed graphitic domains. Their near-perfect alignment and high longitudinal crystallinity that increased the shear strength between CNTs while retaining notable flexibility. The resulting fibers have an exceptional combination of high tensile strength (6.57 GPa), modulus (629 GPa), thermal conductivity (482 W/m·K), and electrical conductivity (2.2 MS/m), thereby overcoming the limits associated with conventional synthetic fibers.
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Affiliation(s)
- Dongju Lee
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology (KIST), Wanju 55324, Republic of Korea
- Department of Advanced Materials Engineering, Center for Advanced Material Analysis, The University of Suwon, Suwon 18323, Republic of Korea
| | - Seo Gyun Kim
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology (KIST), Wanju 55324, Republic of Korea
| | - Seungki Hong
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology (KIST), Wanju 55324, Republic of Korea
| | - Cristina Madrona
- IMDEA Materials Institute, Eric Kandel 2, Getafe, Madrid 28906, Spain
- Facultad de Ciencias, Universidad Autónoma de Madrid, Francisco Tomás y Valiente 7, Madrid 28049, Spain
| | - Yuna Oh
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology (KIST), Wanju 55324, Republic of Korea
| | - Min Park
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology (KIST), Wanju 55324, Republic of Korea
| | - Natsumi Komatsu
- Department of Electrical & Computer Engineering and the Carbon Hub, Rice University, Houston, TX 77005, USA
| | - Lauren W. Taylor
- Department of Chemical & Biomolecular Engineering and the Carbon Hub, Rice University, Houston, TX 77005, USA
| | - Bongjin Chung
- Department of Advanced Materials Engineering, Center for Advanced Material Analysis, The University of Suwon, Suwon 18323, Republic of Korea
| | - Jungwon Kim
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology (KIST), Wanju 55324, Republic of Korea
| | - Jun Yeon Hwang
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology (KIST), Wanju 55324, Republic of Korea
| | - Jaesang Yu
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology (KIST), Wanju 55324, Republic of Korea
| | - Dong Su Lee
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology (KIST), Wanju 55324, Republic of Korea
| | - Hyeon Su Jeong
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology (KIST), Wanju 55324, Republic of Korea
| | - Nam Ho You
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology (KIST), Wanju 55324, Republic of Korea
| | - Nam Dong Kim
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology (KIST), Wanju 55324, Republic of Korea
| | - Dae-Yoon Kim
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology (KIST), Wanju 55324, Republic of Korea
| | - Heon Sang Lee
- Department of Chemical Engineering, Dong-A University, Busan 49315, Republic of Korea
| | - Kun-Hong Lee
- Department of Chemical Engineering, Pohang University of Science & Technology, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Junichiro Kono
- Departments of Electrical & Computer Engineering, Physics & Astronomy, and Materials Science & NanoEngineering, the Smalley-Curl Institute, and the Carbon Hub, Rice University, Houston, TX 77005, USA
| | - Geoff Wehmeyer
- Department of Mechanical Engineering and the Carbon Hub, Rice University, Houston, TX 77005, USA
| | - Matteo Pasquali
- Departments of Chemical Engineering & Biomolecular Engineering, Chemistry, and Materials Science & NanoEngineering and The Carbon Hub, Rice University, 6100 Main Street, Houston, TX 77005, USA
| | - Juan J. Vilatela
- IMDEA Materials Institute, Eric Kandel 2, Getafe, Madrid 28906, Spain
| | - Seongwoo Ryu
- Department of Advanced Materials Engineering, Center for Advanced Material Analysis, The University of Suwon, Suwon 18323, Republic of Korea
| | - Bon-Cheol Ku
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology (KIST), Wanju 55324, Republic of Korea
- Department of Nano Convergence, Jeonbuk National University, Jeonju 54896, Republic of Korea
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9
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Kim YJ, Seo TH, Kim YH, Suh EK, Bae S, Hwang JY, Kim J, Kang Y, Kim MJ, Ahn S. Two-Dimensional Stacked Composites of Self-Assembled Alkane Layers and Graphene for Transparent Gas Barrier Films with Low Permeability. Nano Lett 2022; 22:286-293. [PMID: 34978186 DOI: 10.1021/acs.nanolett.1c03761] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Self-assembled alkane layers are introduced between graphene layers to physically block nanometer size defects in graphene and lateral gas pathways between graphene layers. A well-defined hexatriacontane (HTC) monolayer on graphene could cover nanometer-size defects because of the flexible nature and strong intermolecular van der Waals interactions of alkane, despite the roughness of graphene. In addition, HTC multilayers between graphene layers greatly improve their adhesion. This indicates that HTC multilayers between graphene layers can effectively block the lateral pathway between graphene layers by filling open space with close-packed self-assembled alkanes. By these mechanisms, alternately stacked composites of graphene and self-assembled alkane layers greatly increase the gas-barrier property to a water vapor transmission rate (WVTR) as low as 1.2 × 10-3 g/(m2 day), whereas stacked graphene layers generally show a WVTR < 0.5 g/(m2 day). Furthermore, the self-assembled alkane layers have superior crystallinity and wide bandgap, so they have little effect on the transmittance.
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Affiliation(s)
- Yoon-Jeong Kim
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology (KIST), Jeonbuk 55324, Republic of Korea
- Department of Chemistry, Research Institute for Natural Sciences and Institute of Nano Science and Technology, Hanyang University, Seoul 04763, Republic of Korea
| | - Tae Hoon Seo
- Green Energy & Nano Technology R&D group, Korea Institute of Industrial Technology, Gwangju 61012, Republic of Korea
| | - Yang Hui Kim
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology (KIST), Jeonbuk 55324, Republic of Korea
| | | | - Sukang Bae
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology (KIST), Jeonbuk 55324, Republic of Korea
| | - Jun Yeon Hwang
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology (KIST), Jeonbuk 55324, Republic of Korea
| | - Jaewoo Kim
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology (KIST), Jeonbuk 55324, Republic of Korea
| | - Youngjong Kang
- Department of Chemistry, Research Institute for Natural Sciences and Institute of Nano Science and Technology, Hanyang University, Seoul 04763, Republic of Korea
| | - Myung Jong Kim
- Department of Chemistry, Gachon University, Gyeonggi-do 13120, Republic of Korea
| | - Seokhoon Ahn
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology (KIST), Jeonbuk 55324, Republic of Korea
- Department of Chemistry, Jeonbuk National University, Jeonbuk 54896, Republic of Korea
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10
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Yu S, Hwang YH, Lee KT, Kim SO, Hwang JY, Hong SH. Outstanding Strengthening and Toughening Behavior of 3D-Printed Fiber-Reinforced Composites Designed by Biomimetic Interfacial Heterogeneity. Adv Sci (Weinh) 2022; 9:e2103561. [PMID: 34821483 PMCID: PMC8787430 DOI: 10.1002/advs.202103561] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 10/28/2021] [Indexed: 06/13/2023]
Abstract
3D printing of fiber-reinforced composites is expected to be the forefront technology for the next-generation high-strength, high-toughness, and lightweight structural materials. The intrinsic architecture of 3D-printed composites closely represents biomimetic micro/macrofibril-like hierarchical structure composed of intermediate filament assembly among the micron-sized reinforcing fibers, and thus contributes to a novel mechanism to simultaneously improve mechanical properties and structural features. Notably, it is found that an interfacial heterogeneity between numerous inner interfaces in the hierarchical structure enables an exceptional increase in the toughness of composites. The strong interfacial adhesion between the fibers and matrix, with accompanying the inherently weak interfacial adhesion between intermediate filaments and the resultant interfacial voids, provide a close representation of the toughness behavior of natural architectures relying on the localized heterogeneity. Given the critical embedment length of fiber reinforcement, extraordinary improvement has been attained not only in the strength but also in toughness taking advantage of the synergy effect from the aforementioned nature-inspired features. Indeed, the addition of a small amount of short fiber to the brittle bio-filaments results in a noticeable increase of more than 200% in the tensile strength and modulus with further elongation increment. This article highlights the inherent structural hierarchy of 3D-printed composites and the relevant sophisticated mechanism for anomalous mechanical reinforcement.
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Affiliation(s)
- Siwon Yu
- Department of Material Science and EngineeringKorea Advanced Institute of Science and Technology (KAIST)291 Daehak‐ro, Yuseong‐guDaejeon34141Republic of Korea
- Institute of Advanced Composite MaterialsKorea Institute of Science and Technology (KIST)Jeonbuk55324Republic of Korea
| | - Yun Hyeong Hwang
- Institute of Advanced Composite MaterialsKorea Institute of Science and Technology (KIST)Jeonbuk55324Republic of Korea
| | - Kang Taek Lee
- Department of Mechanical EngineeringKorea Advanced Institute of Science and Technology (KAIST)291 Daehak‐ro, Yuseong‐guDaejeon34141Republic of Korea
| | - Sang Ouk Kim
- National Creative Research Initiative Center for Multi‐dimensional Nanoscale AssemblyKorea Advanced Institute of Science and Technology (KAIST)291 Daehak‐ro, Yuseong‐guDaejeon34141Republic of Korea
| | - Jun Yeon Hwang
- Institute of Advanced Composite MaterialsKorea Institute of Science and Technology (KIST)Jeonbuk55324Republic of Korea
| | - Soon Hyung Hong
- Department of Material Science and EngineeringKorea Advanced Institute of Science and Technology (KAIST)291 Daehak‐ro, Yuseong‐guDaejeon34141Republic of Korea
- Nanotechnology Research InstituteJiaxing UniversityJiaxingChina
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11
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Kang MG, Kim KH, Park HW, Koh JS, Hwang SJ, Hwang JY, Park JR. Percutaneous coronary intervention in patients with peripheral artery disease and adverse cardiovascular adverse event and bleeding. Eur Heart J 2021. [DOI: 10.1093/eurheartj/ehab724.1149] [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: 11/13/2022] Open
Abstract
Abstract
Background
Peripheral artery disease (PAD) increase the risk of comorbidity and mortality in coronary artery disease (CAD).
Objectives
We evaluate influence of PAD on prognosis in patients undergoing percutaneous coronary intervention (PCI).
Methods
We analyzed all consecutive patients included in our dedicated local registry for PCI between January 2011 and December 2016. Presence of PAD was defined by decreased ankle-brachial index (<0.9). Major adverse cardiovascular event (MACE) was defined as a composite of cardiovascular death, non-fatal myocardial infarct, revascularization, and ischemic stroke. Major bleeding was defined as Bleeding Academic Research Consortium 3 or 5.
Results
Among the 4,747 patients who underwent the PCI, 12.9% (n=610) of PAD were identified. Old age (>60 years), renal dysfunction, reduced ejection fraction, and presence of PAD were predictors with both MACE and major bleeding event. Among them, presence of PAD was an independent risk factor of MACE and major bleeding (MACE, HR 8.26, 95% CI 2.33- 29.41, p=0.036; major bleeding, HR 3.11, 95% CI 1.10–10.63, p=0.040, respectively). The MACE and major bleeding rate at 5-year was significantly increased in patients with PAD (MACE, 30.0% vs. 15.8%, log rank test p<0.001; major bleeding, 6.7 vs. 3.6%, log rank test p=0.003, respectively) (Figure).
Conclusion
Presence of PAD was strongly associated with higher rate of long-term MACE and major bleeding. These findings could have a clinical relevance in requiring individualized pharmacologic strategies to reduce the burden of cardiovascular disease.
Funding Acknowledgement
Type of funding sources: None.
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Affiliation(s)
- M G Kang
- Gyeongsang National University Hospital, Cardiology, Jinju, Korea (Republic of)
| | - K H Kim
- Gyeongsang National University Hospital, Cardiology, Jinju, Korea (Republic of)
| | - H W Park
- Gyeongsang National University Hospital, Cardiology, Jinju, Korea (Republic of)
| | - J S Koh
- Gyeongsang National University Hospital, Cardiology, Jinju, Korea (Republic of)
| | - S J Hwang
- Gyeongsang National University Hospital, Cardiology, Jinju, Korea (Republic of)
| | - J Y Hwang
- Gyeongsang National University Hospital, Cardiology, Jinju, Korea (Republic of)
| | - J R Park
- Gyeongsang National University Hospital, Cardiology, Jinju, Korea (Republic of)
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12
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Kang MG, Kim KH, Park HW, Koh JS, Park JR, Park YH, Hwang SJ, Jeong YH, Kwak CH, Ahn JH, Song HN, Hwang JY. Impact of active and stable cancer on survival in patients undergoing percutaneous coronary intervention. Eur Heart J 2021. [DOI: 10.1093/eurheartj/ehab724.2858] [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
With advances in treatment of ischemic heart disease and cancer treatment, use of percutaneous coronary intervention (PCI) in cancer survivors and patients with active cancer (AC) is expanding.
Objectives
The purpose of this study was to determine the impact of cancer on survival and major cardiovascular events (MACE) in a long-term, single-center cohort of patients treated with PCI.
Methods
Patients treated with PCI between January 2010 and December 2017 were grouped as follows: controls (patients without cancer), stable cancer (SC), and AC. AC was included patients with cancer diagnosed within the past 6 months, patients who had cancer-related therapy within the past 6 months, active metastatic disease, or active recurrence of the cancer. The primary endpoints were 5-year survival and a secondary endpoint was 5-year MACE.
Results
A total of 6,743 patients (age 66±12 years, 68.4% men) treated with PCI were included: 6,404 (95.0%) controls, 245 (3.6%) SC, and 94 (1.4%) AC. Predominant malignancies were gastrointestinal (37.4%), lung (22.7%), and genitourinary cancer (14.7%). No differences were observed between patients with AC, SC and controls regarding 5-year MACE (total MACE, 33.2% vs. 28.1% vs. 17.5%, p=0.072; cardiac death, 13.6% vs. 9.1% vs. 6.7%, p=0.066; non-fatal myocardial infarction, 2.9% vs. 7.5% vs. 7.8%, p=0.820; revascularization, 17.9% vs. 17.6% vs. 11.6%, p=0.794, respectively). Patients with AC and SC had reduced 5-year survival compared with controls (62.0% vs. 81.5% vs. 89.8%, p<0.001) (Figure). AC was associated with a 1.76 (95% CI 1.22 to 2.54, p=0.002) fold increased risk of all-cause 5-year mortality in multivariable adjusted models.
Conclusions
Cumulative incidence of 5-year survival was discriminated by concurrent status of cancer following PCI. Individualized decision making is needed in the routine practice of PCI regarding concurrent cancer-specific treatment and prognosis.
Funding Acknowledgement
Type of funding sources: None.
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Affiliation(s)
- M G Kang
- Gyeongsang National University Hospital, Jinju, Korea (Republic of)
| | - K H Kim
- Gyeongsang National University Hospital, Cardiology, Jinju, Korea (Republic of)
| | - H W Park
- Gyeongsang National University Hospital, Cardiology, Jinju, Korea (Republic of)
| | - J S Koh
- Gyeongsang National University Hospital, Cardiology, Jinju, Korea (Republic of)
| | - J R Park
- Gyeongsang National University Hospital, Cardiology, Jinju, Korea (Republic of)
| | - Y H Park
- Gyeongsang National University Changwon Hospital, Changwon, Korea (Republic of)
| | - S J Hwang
- Gyeongsang National University Hospital, Cardiology, Jinju, Korea (Republic of)
| | - Y H Jeong
- Gyeongsang National University Changwon Hospital, Changwon, Korea (Republic of)
| | - C H Kwak
- Gyeongsang National University Changwon Hospital, Changwon, Korea (Republic of)
| | - J H Ahn
- Gyeongsang National University Changwon Hospital, Changwon, Korea (Republic of)
| | - H N Song
- Gyeongsang National University Hospital, Jinju, Korea (Republic of)
| | - J Y Hwang
- Gyeongsang National University Hospital, Cardiology, Jinju, Korea (Republic of)
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13
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Man Kadayat T, Eun Kim D, Bong Lee S, Jung K, Eun Park S, Hong JY, Kim J, Shrestha A, Kim DS, An H, Kim N, Lee SJ, Kwon S, Kim S, Yeon Hwang J, Kim S, Hahn D, Choi H, Nam SJ, Hyun Jeon Y, Jin Hwang J, Jin Cho S, Chin J. Antioxidative and anti-inflammatory activity of psiguadial B and its halogenated analogues as potential neuroprotective agents. Bioorg Chem 2021; 113:105027. [PMID: 34098398 DOI: 10.1016/j.bioorg.2021.105027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 04/29/2021] [Accepted: 05/24/2021] [Indexed: 11/19/2022]
Abstract
Psiguadial B (8), and its fluoro- (8a), chloro- (8b), and bromo- (8c) derivatives were synthesized using a sodium acetate-catalyzed single step coupling of three components: β-caryophyllene (5), diformylphloroglucinol (11), and benzaldehyde (12). These compounds efficiently and dose-dependently decreased H2O2-induced cell death, a quantitative marker of cell death, in primary cultures of mouse cortical neurons. Psiguadial B also decreased neuronal death and accumulation of ROS induced by FeCl2 in cortical cultures. The in vitro effects of these compounds in lipopolysaccharide (LPS)-induced expression of nitric oxide (NO), and TNF-α and IL-6 by suppressing the NF-κB pathway in immune cells demonstrated their antioxidative and anti-inflammatory activity. The present findings warrant further research on the development of psiguadial B-based neuroprotective agents for the treatment of neurodegenerative diseases, acute brain injuries and immunological disorders.
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Affiliation(s)
- Tara Man Kadayat
- New Drug Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu 41061, Republic of Korea
| | - Dong Eun Kim
- Asan Institute for Life Sciences, Asan Medical Center, Seoul 05505, Republic of Korea
| | - Sang Bong Lee
- Vaccine Commercialization Center, Gyeongbuk Institute for Bio Industry, Andong 33618, Republic of Korea
| | - Kyungjin Jung
- New Drug Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu 41061, Republic of Korea
| | - Sang Eun Park
- Asan Institute for Life Sciences, Asan Medical Center, Seoul 05505, Republic of Korea
| | - Ji-Ye Hong
- Asan Institute for Life Sciences, Asan Medical Center, Seoul 05505, Republic of Korea
| | - Jina Kim
- New Drug Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu 41061, Republic of Korea
| | - Aarajana Shrestha
- New Drug Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu 41061, Republic of Korea
| | - Dong-Su Kim
- Therapeutics and Biotechnology Division, Korea Research Institute of Chemical Technology, 34114 Daejeon, Republic of Korea
| | - Hongchan An
- New Drug Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu 41061, Republic of Korea
| | - Nayeon Kim
- New Drug Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu 41061, Republic of Korea
| | - Su-Jeong Lee
- New Drug Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu 41061, Republic of Korea
| | - Sugyeong Kwon
- New Drug Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu 41061, Republic of Korea
| | - Suhui Kim
- New Drug Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu 41061, Republic of Korea
| | - Jun Yeon Hwang
- New Drug Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu 41061, Republic of Korea
| | - Shinae Kim
- New Drug Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu 41061, Republic of Korea
| | - Dongyup Hahn
- School of Food Science and Biotechnology, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Hyukjae Choi
- College of Pharmacy, Yeungnam University, Gyeongbuk 38541, Republic of Korea
| | - Sang-Jip Nam
- Department of Chemistry and Nanoscience, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Yong Hyun Jeon
- Laboratory Animal Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu 41061, Republic of Korea
| | - Jung Jin Hwang
- Asan Institute for Life Sciences, Asan Medical Center, Seoul 05505, Republic of Korea; Department of Convergence Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Republic of Korea.
| | - Sung Jin Cho
- Convergence Research Center for Diagnosis, Treatment and Care System of Dementia, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea.
| | - Jungwook Chin
- New Drug Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu 41061, Republic of Korea.
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14
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Lee YH, Cha HM, Hwang JY, Park SY, Vishakantegowda AG, Imran A, Lee JY, Yi YS, Jun S, Kim GH, Kang HJ, Chung SJ, Kim M, Kim H, Han SB. Sulfamoylbenzamide-based Capsid Assembly Modulators for Selective Inhibition of Hepatitis B Viral Replication. ACS Med Chem Lett 2021; 12:242-248. [PMID: 33603970 PMCID: PMC7883466 DOI: 10.1021/acsmedchemlett.0c00606] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 12/29/2020] [Indexed: 02/08/2023] Open
Abstract
As the spread of infections caused by hepatitis B virus (HBV) threatens public health worldwide, investigations from multiple perspectives and of various mechanisms of action are urgently required to increase the HBV cure rate. Targeting the encapsidation of the nuclear capsid protein (core protein, HBc) has emerged as an attractive strategy for inhibiting the viral assembly process; however, a drug targeting this mechanism has not yet been approved. We synthesized novel sulfamoylbenzamides (SBAs) as capsid assembly modulators of HBV and found that the effects and safety profiles of compounds 3 and 8 have potential therapeutic applicability against HBV. The formation of tubular particles was time-dependent in the presence of 3, indicating a new mode of protein assembly by SBA compounds. Our findings provide a new entity for developing safe and efficient treatments for HBV infection.
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Affiliation(s)
- Yeon Hee Lee
- Therapeutics
& Biotechnology Division, Korea Research
Institute of Chemical Technology, Daejeon 34114, Republic of Korea
- Department
of Medicinal Chemistry and Pharmacology, University of Science & Technology, Daejeon 34113, Republic of Korea
| | - Hyeon-Min Cha
- Therapeutics
& Biotechnology Division, Korea Research
Institute of Chemical Technology, Daejeon 34114, Republic of Korea
- Graduate
School of New Drug Discovery and Development, Chungnam National University, Daejeon 34134, Republic
of Korea
| | - Jun Yeon Hwang
- Therapeutics
& Biotechnology Division, Korea Research
Institute of Chemical Technology, Daejeon 34114, Republic of Korea
| | - So Yeong Park
- Therapeutics
& Biotechnology Division, Korea Research
Institute of Chemical Technology, Daejeon 34114, Republic of Korea
- Department
of Medicinal Chemistry and Pharmacology, University of Science & Technology, Daejeon 34113, Republic of Korea
| | - Avinash G. Vishakantegowda
- Therapeutics
& Biotechnology Division, Korea Research
Institute of Chemical Technology, Daejeon 34114, Republic of Korea
- Department
of Medicinal Chemistry and Pharmacology, University of Science & Technology, Daejeon 34113, Republic of Korea
| | - Ali Imran
- Therapeutics
& Biotechnology Division, Korea Research
Institute of Chemical Technology, Daejeon 34114, Republic of Korea
| | - Joo-Youn Lee
- Therapeutics
& Biotechnology Division, Korea Research
Institute of Chemical Technology, Daejeon 34114, Republic of Korea
| | - Yoon-Sun Yi
- Center
for Research Equipment, Korea Basic Science
Institute, Cheongju 28119, Republic of Korea
| | - Sangmi Jun
- Center
for Research Equipment, Korea Basic Science
Institute, Cheongju 28119, Republic of Korea
| | - Ga Hyeon Kim
- School
of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea
- AbTis Co.
Ltd. Suwon Venture Valley II, 142-10, Saneop-ro 156, Gwonseon-gu, Suwon 16648, Republic of Korea
| | - Hyo Jin Kang
- AbTis Co.
Ltd. Suwon Venture Valley II, 142-10, Saneop-ro 156, Gwonseon-gu, Suwon 16648, Republic of Korea
| | - Sang J. Chung
- School
of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea
- AbTis Co.
Ltd. Suwon Venture Valley II, 142-10, Saneop-ro 156, Gwonseon-gu, Suwon 16648, Republic of Korea
| | - Meehyein Kim
- Therapeutics
& Biotechnology Division, Korea Research
Institute of Chemical Technology, Daejeon 34114, Republic of Korea
- Graduate
School of New Drug Discovery and Development, Chungnam National University, Daejeon 34134, Republic
of Korea
| | - Hyejin Kim
- Therapeutics
& Biotechnology Division, Korea Research
Institute of Chemical Technology, Daejeon 34114, Republic of Korea
| | - Soo Bong Han
- Therapeutics
& Biotechnology Division, Korea Research
Institute of Chemical Technology, Daejeon 34114, Republic of Korea
- Department
of Medicinal Chemistry and Pharmacology, University of Science & Technology, Daejeon 34113, Republic of Korea
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15
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Lee Y, Koo J, Lee S, Yoon J, Kim K, Jang M, Jang J, Choe J, Li B, Le CT, Ullah F, Kim YS, Hwang JY, Lee WC, Ruoff RS, Cheong H, Cheon J, Lee H, Kim K. Universal Oriented van der Waals Epitaxy of 1D Cyanide Chains on Hexagonal 2D Crystals. Adv Sci (Weinh) 2020; 7:1900757. [PMID: 32099750 PMCID: PMC7029641 DOI: 10.1002/advs.201900757] [Citation(s) in RCA: 8] [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] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 11/26/2019] [Indexed: 05/05/2023]
Abstract
The atomic or molecular assembly on 2D materials through the relatively weak van der Waals interaction is quite different from the conventional heteroepitaxy and may result in unique growth behaviors. Here, it is shown that straight 1D cyanide chains display universal epitaxy on hexagonal 2D materials. A universal oriented assembly of cyanide crystals (AgCN, AuCN, and Cu0.5Au0.5CN) is observed, where the chains are aligned along the three zigzag lattice directions of various 2D hexagonal crystals (graphene, h-BN, WS2, MoS2, WSe2, MoSe2, and MoTe2). The potential energy landscape of the hexagonal lattice induces this preferred alignment of 1D chains along the zigzag lattice directions, regardless of the lattice parameter and surface elements as demonstrated by first-principles calculations and parameterized surface potential calculations. Furthermore, the oriented microwires can serve as crystal orientation markers, and stacking-angle-controlled vertical 2D heterostructures are successfully fabricated by using them as markers. The oriented van der Waals epitaxy can be generalized to any hexagonal 2D crystals and will serve as a unique growth process to form crystals with orientations along the zigzag directions by epitaxy.
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Affiliation(s)
- Yangjin Lee
- Department of PhysicsYonsei UniversitySeoul03722Korea
- Center for NanomedicineInstitute for Basic Science (IBS)Seoul03722Korea
| | - Jahyun Koo
- Department of PhysicsKonkuk UniversitySeoul05029Korea
| | - Sol Lee
- Department of PhysicsYonsei UniversitySeoul03722Korea
- Center for NanomedicineInstitute for Basic Science (IBS)Seoul03722Korea
| | - Jun‐Yeong Yoon
- Department of PhysicsYonsei UniversitySeoul03722Korea
- Center for NanomedicineInstitute for Basic Science (IBS)Seoul03722Korea
| | - Kangwon Kim
- Department of PhysicsSogang UniversitySeoul04107Korea
| | | | - Jeongsu Jang
- Department of PhysicsYonsei UniversitySeoul03722Korea
- Department of PhysicsUlsan National Institute of Science and Technology (UNIST)Ulsan44919Korea
| | | | - Bao‐Wen Li
- Center for Multidimensional Carbon Materials (CMCM)Institute for Basic Science (IBS)Ulsan44919Korea
| | - Chinh Tam Le
- Department of Physics and Energy Harvest‐Storage Research CenterUniversity of UlsanUlsan44610Korea
| | - Farman Ullah
- Department of Physics and Energy Harvest‐Storage Research CenterUniversity of UlsanUlsan44610Korea
| | - Yong Soo Kim
- Department of Physics and Energy Harvest‐Storage Research CenterUniversity of UlsanUlsan44610Korea
| | - Jun Yeon Hwang
- Institute of Advanced Composite MaterialsKorea Institute of Science and Technology (KIST)Jeonbuk55324Korea
| | - Won Chul Lee
- Department of Mechanical EngineeringHanyang UniversityAnsan15588Korea
| | - Rodney S. Ruoff
- Center for Multidimensional Carbon Materials (CMCM)Institute for Basic Science (IBS)Ulsan44919Korea
- Department of ChemistryUlsan National Institute of Science and Technology (UNIST)Ulsan44919Korea
- School of Materials Science and EngineeringUlsan National Institute of Science and Technology (UNIST)Ulsan44919Korea
- School of Energy and Chemical EngineeringUlsan National Institute of Science and Technology (UNIST)Ulsan44919Korea
| | | | - Jinwoo Cheon
- Center for NanomedicineInstitute for Basic Science (IBS)Seoul03722Korea
- Department of ChemistryYonsei UniversitySeoul03722Korea
- Graduate Program of Nano Biomedical EngineeringYonsei‐IBS InstituteYonsei UniversitySeoul03722Korea
| | - Hoonkyung Lee
- Department of PhysicsKonkuk UniversitySeoul05029Korea
| | - Kwanpyo Kim
- Department of PhysicsYonsei UniversitySeoul03722Korea
- Center for NanomedicineInstitute for Basic Science (IBS)Seoul03722Korea
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16
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Kim K, Kim HR, Kang MG, Park HY, Koh JS, Hwang SJ, Hwang JY, Park JR. P1416 Clinical importance of consecutive transthoracic echocardiography in the patients with hypertrophic cardiomyopathy. Eur Heart J Cardiovasc Imaging 2020. [DOI: 10.1093/ehjci/jez319.848] [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
Funding Acknowledgements
nothing
OnBehalf
nothing
Background
prediction of outcomes Hypertrophic cardiomyopathy (HCM) have been robustly analyzed with echocardiography. However, there is limited data of serial follow-up (FU) transthoracic echocardiography (TTE) to predict outcomes in patients with HCM.
Objectives
This study aim is to discover clinical predictors associated with consecutive TTE follow-up in patients with HCM.
Methods
From 2010 to 2016, 162 patients with HCM were enrolled retrospectively. Concentric LVH and others systolic disease related to wall thickness were excluded. Index TTE (baseline) was measured when firstly admitted in our hospital. FU TTE was analyzed at the end of follow-up, defined as the last recorded value in patients who did not develop events or the last recorded value before events developed.
Results
The average of FU TTE and clinical FU period was 3.7 ± 2.0 years. Clinical outcomes were defined as stroke, syncope, heart failure, arrhythmia and death. Interestingly, only baseline TR V max was a predictor for clinical outcome whereas the others echo parameters were not associated with events (Table 1). KM curve showed the TR Vmax ≥2.5m/s was also significant (log rank = 0.008, Fig 1.)
Conclusions Our study showed short-term FU TTE did not bring clinician with clinical benefits in the aspect of prediction for events. Only baseline TR V max was good correlation with cardiovascular outcomes and even in the survival analysis.
Serial TTE and changed values Total N = 162 index TTE (baseline) FU TTE Change of FU per year event no event p-value event no event p-value event no event p-value IVDd, mm 14 ± 4 15 ± 5 0.500 15 ± 5 14 ± 5 0.758 0.23 ± 0.51 -0.07 ± 1.27 0.200 LVIDd, mm 47 ± 5 48 ± 6 0.256 47 ± 7 48 ± 6 0.560 -0.22 ± 2.79 0.10 ± 2.27 0.444 LVEF, % 62 ± 5 61 ± 7 0.379 61 ± 6 61 ± 10 0.927 -0.43 ± 3.10 -0.04 ± 4.94 0.620 LAVI 43 ± 9 43 ± 8 0.879 57 ± 27 58 ± 23 0.849 0.53 ± 14.5 3.11 ± 7.2 0.134 EA ratio 0.9 ± 0.6 0.9 ± 0.6 0.782 1.0 ± 0.8 0.9 ± 0.6 0.595 -0.02 ± 0.76 0.003 ± 0.027 0.594 DT,ms 196 ± 58 201 ± 62 0.603 203 ± 91 217 ± 89 0.370 17 ± 57 5 ± 40 0.154 septal e` 4.4 ± 2.1 4.2 ± 1.6 0.585 4.4 ± 1.6 4.6 ± 1.7 0.438 0.24 ± 0.91 0.05 ± 0.65 0.190 E of e` 17 ± 11 17 ± 23 0.993 15 ± 9 15 ± 6 0.726 -0.48 ± 4.42 -1.66 ± 22.78 0.728 TR velocity 2.6 ± 0.5 2.4 ± 0.4 0.012 2.7 ± 0.6 2.6 ± 0.4 0.604 0.05 ± 0.30 0.04 ± 0.18 0.905 Max wall thickness 17 ± 3 18 ± 3 0.137 17 ± 4 17 ± 3 0.888 -0.01 ± 2.19 -0.18 ± 1.14 0.522
Abstract P1416 Figure. TR Vmax and CV outcomes in the KM curve
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Affiliation(s)
- K Kim
- Gyeongsang National University Hospital, Cardiology, Jinju, Korea (Republic of)
| | - H R Kim
- Gyeongsang National University Hospital, Cardiology, Jinju, Korea (Republic of)
| | - M G Kang
- Gyeongsang National University Hospital, Cardiology, Jinju, Korea (Republic of)
| | - H Y Park
- Gyeongsang National University Hospital, Cardiology, Jinju, Korea (Republic of)
| | - J S Koh
- Gyeongsang National University Hospital, Cardiology, Jinju, Korea (Republic of)
| | - S J Hwang
- Gyeongsang National University Hospital, Cardiology, Jinju, Korea (Republic of)
| | - J Y Hwang
- Gyeongsang National University Hospital, Cardiology, Jinju, Korea (Republic of)
| | - J R Park
- Gyeongsang National University Hospital, Cardiology, Jinju, Korea (Republic of)
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Hong HJ, Yu H, Hong S, Hwang JY, Kim SM, Park MS, Jeong HS. Modified tunicate nanocellulose liquid crystalline fiber as closed loop for recycling platinum-group metals. Carbohydr Polym 2019; 228:115424. [PMID: 31635723 DOI: 10.1016/j.carbpol.2019.115424] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Revised: 09/10/2019] [Accepted: 10/01/2019] [Indexed: 01/28/2023]
Abstract
Rising demand and elemental rarity requires the recycling of precious metals such as platinum group elements (PGMs). Recently, biosorption has been focused on the capability of recovering precious metals, but in practice, recycling is inefficient or far away from a closed-loop material system. Here we use a polyethylenimine (PEI)-grafted spun-fiber made of cellulose nanofibril (CNF) extracted from a tunicate as a biosorbent for PGMs. Liquid crystallinity (LC) of TCNF suspension appears to contribute the generation of well-developed open porous structure in the fiber. We show the fiber has the selectivity and high capacity of Pt (120.2 mg/g, 86%) and Pd (26.5 mg/g, 74.2%) adsorption under the presence of other metals in simulated automobile waste. The adsorbed Pt and Pd with nano-scale clusters were uniformly distributed on the porous surface, which were directly applied as a catalyst. These results propose an easy approach to recover precious metals and reuse them directly, thereby closing loops of metal recycling.
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Affiliation(s)
- Hye-Jin Hong
- Mineral Resources Research Division, Korea Institute of Geoscience and Mineral Resources (KIGAM), Daejeon, 34132, Republic of Korea
| | - Hayoung Yu
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology, 92 Chudongro, Bondong-eup, Wanju-gun, Jeonbuk, 565-905, Republic of Korea
| | - Seungki Hong
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology, 92 Chudongro, Bondong-eup, Wanju-gun, Jeonbuk, 565-905, Republic of Korea
| | - Jun Yeon Hwang
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology, 92 Chudongro, Bondong-eup, Wanju-gun, Jeonbuk, 565-905, Republic of Korea
| | - Seung Min Kim
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology, 92 Chudongro, Bondong-eup, Wanju-gun, Jeonbuk, 565-905, Republic of Korea
| | - Min Sang Park
- Global Technology, SK Innovation, 325, Exporo, Yuseong-gu, Daejeon, 34124, Republic of Korea.
| | - Hyeon Su Jeong
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology, 92 Chudongro, Bondong-eup, Wanju-gun, Jeonbuk, 565-905, Republic of Korea.
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Jang JY, Ahn JH, Bae JS, Kang MG, Kim K, Park HW, Koh JS, Park Y, Hwang SJ, Kwak CH, Hwang JY, Jeong YH. P3637Relationship between serial measurements of NT-proBNP and cardiovascular events in patients with acute coronary syndrome. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz745.0494] [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
Increased level of natriuretic peptides has been known as an important predictors of adverse cardiovascular (CV) outcomes in patients with acute coronary syndrome (ACS). We sought to evaluate clinical implication of N-terminal pro-brain natriuretic peptide (NT-proBNP) measured at initial and follow-up periods.
Methods
Serial NT-proBNP levels (on-admission and one-month post-PCI) were measured in ACS patients undergoing PCI (n=2,290). High NT-proBNP levels were determined according to the predefined age-specific criteria. Patients were stratified into 4 groups according to NT-proBNP levels (on-admission & one-month): (1) normal-normal group (n=1234, 53.9%); (2) high–normal group (n=257, 11.2%); (3) normal-high group (n=376, 16.4%); and (4) high-high group (n=423, 18.5%). Clinical events were defined as all-cause death and MACE (a composite of CV death, non-fatal MI, and ischemic stroke).
Results
With a median follow-up of 35.9 (IQR: 16.8, 54.5) months, all-cause death and MACE were occurred in 4.1% and 7.2%, respectively. NT-proBNP on-admission vs. at one-month did not differ significantly (median 391.6 [IQR: 143.9, 1402.3] vs. median 619.1 [IQR 240.1, 1616.1]; p=0.622), but the prevalence of high NT-proBNP was increased over time (25.3% to 34.9%; p<0.001). The rates of all-cause death and MACE significantly increased only in the high-high group compared with other groups (log-rank test, all p values <0.001, Figure). After adjustment, the high-high group remained significantly risky in terms with the occurrence of all-cause death (HR, 2.99; 95% CI, 1.65 to 5.41; p<0.001) and MACE (HR, 1.96; 95% CI, 1.28 to 3.01; p=0.002).
Figure 1
Conclusion
Serial measurements of NT-proBNP at on-admission and follow-up can help to stratify the risks of all-cause death and adverse CV events following PCI in ACS patients. About two-fifths of patients having high NT-proBNP level during hospitalization can be classified into the low-risk group for all-cause death and adverse CV events.
Acknowledgement/Funding
None
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Affiliation(s)
- J Y Jang
- Gyeongsang National University Changwon Hospital, Internal Medicine, Changwon, Korea (Republic of)
| | - J H Ahn
- Gyeongsang National University Changwon Hospital, Internal Medicine, Changwon, Korea (Republic of)
| | - J S Bae
- Gyeongsang National University Changwon Hospital, Internal Medicine, Changwon, Korea (Republic of)
| | - M G Kang
- Gyeongsang National University Hospital, Internal Medicine, Jinju, Korea (Republic of)
| | - K Kim
- Gyeongsang National University Hospital, Internal Medicine, Jinju, Korea (Republic of)
| | - H W Park
- Gyeongsang National University Hospital, Internal Medicine, Jinju, Korea (Republic of)
| | - J S Koh
- Gyeongsang National University Hospital, Internal Medicine, Jinju, Korea (Republic of)
| | - Y Park
- Gyeongsang National University Changwon Hospital, Internal Medicine, Changwon, Korea (Republic of)
| | - S J Hwang
- Gyeongsang National University Hospital, Internal Medicine, Jinju, Korea (Republic of)
| | - C H Kwak
- Gyeongsang National University Changwon Hospital, Internal Medicine, Changwon, Korea (Republic of)
| | - J Y Hwang
- Gyeongsang National University Hospital, Internal Medicine, Jinju, Korea (Republic of)
| | - Y H Jeong
- Gyeongsang National University Changwon Hospital, Internal Medicine, Changwon, Korea (Republic of)
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Kim M, Hwang JY, Choo KS, Ryu H, Reid SNS, Kim YW, Kim TU, Kim JH. Comparison of image quality of abdominopelvic CT in paediatric patients: low osmolar contrast media versus less iodine-containing iso-osmolar contrast media at different peak kilovoltages. Clin Radiol 2019; 74:896.e9-896.e16. [PMID: 31431254 DOI: 10.1016/j.crad.2019.06.027] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 06/21/2019] [Indexed: 10/26/2022]
Abstract
AIM To evaluate the effect of iso-osmolar contrast media (IOCM) at different tube voltages on image quality for abdominal computed tomography (CT) in paediatric patients. MATERIALS AND METHODS The low osmolar contrast media (LOCM) group and IOCM group consisted of 101 and 102 CT examinations, respectively, in patients <18 years old. Images were reviewed retrospectively. Objective measurement of the contrast enhancement and noise were analysed and contrast-to-noise ratios (CNRs) of the abdominal aorta, portal vein, and liver were calculated. Four radiologists participated in subjective analysis using a four-point scale system to evaluate degrees of contrast enhancement, image noise, beam-hardening artefact, and overall image quality. Reader performance for correctly differentiating the two kinds of contrast media was evaluated. RESULTS Regarding the objective measurement, contrast enhancement was significantly higher in the LOCM group (p<0.05). In subjective analysis, only CT using 120 kVp showed significantly stronger enhancement in the LOCM group (p=0.002), and sensitivity to differentiate the IOCM was 80.6%. Overall sensitivity and specificity for correctly differentiating IOCM were 57.1%, and 56.9%, respectively. CONCLUSION The application of IOCM was found to be feasible for performing paediatric abdominopelvic CT with a low tube voltage protocol. Although objective measurements of contrast enhancement were significantly lower in the IOCM group, subjective contrast enhancement and image quality assessments were not statistically different between groups.
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Affiliation(s)
- M Kim
- Department of Radiology, Pusan National University Yangsan Hospital, Geumo-ro 20, Yangsan-si, Gyeongsangnam-do, 50612, Republic of Korea
| | - J Y Hwang
- Department of Radiology, Pusan National University Yangsan Hospital, Geumo-ro 20, Yangsan-si, Gyeongsangnam-do, 50612, Republic of Korea; Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Geumo-ro 20, Yangsan-si, Gyeongsangnam-do, 50612, Republic of Korea.
| | - K S Choo
- Department of Radiology, Pusan National University Yangsan Hospital, Geumo-ro 20, Yangsan-si, Gyeongsangnam-do, 50612, Republic of Korea
| | - H Ryu
- Department of Radiology, Pusan National University Yangsan Hospital, Geumo-ro 20, Yangsan-si, Gyeongsangnam-do, 50612, Republic of Korea
| | - S N S Reid
- College of Creative Human Resource, School of Liberal Arts Education, Kyungsung University, Busan, 48434, Republic of Korea
| | - Y W Kim
- Department of Radiology, Pusan National University Yangsan Hospital, Geumo-ro 20, Yangsan-si, Gyeongsangnam-do, 50612, Republic of Korea
| | - T U Kim
- Department of Radiology, Pusan National University Yangsan Hospital, Geumo-ro 20, Yangsan-si, Gyeongsangnam-do, 50612, Republic of Korea
| | - J H Kim
- Department of Radiology, Pusan National University Yangsan Hospital, Geumo-ro 20, Yangsan-si, Gyeongsangnam-do, 50612, Republic of Korea
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Tran TN, Jung Kim H, Samdani JS, Hwang JY, Ku BC, Kwan Lee J, Yu JS. A facile in-situ activation of protonated histidine-derived porous carbon for electrochemical capacitive energy storage. J IND ENG CHEM 2019. [DOI: 10.1016/j.jiec.2019.01.044] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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21
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Nakhanivej P, Yu X, Park SK, Kim S, Hong JY, Kim HJ, Lee W, Hwang JY, Yang JE, Wolverton C, Kong J, Chhowalla M, Park HS. Revealing molecular-level surface redox sites of controllably oxidized black phosphorus nanosheets. Nat Mater 2019; 18:156-162. [PMID: 30531848 DOI: 10.1038/s41563-018-0230-2] [Citation(s) in RCA: 90] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Accepted: 10/23/2018] [Indexed: 05/23/2023]
Abstract
Bulk and two-dimensional black phosphorus are considered to be promising battery materials due to their high theoretical capacities of 2,600 mAh g-1. However, their rate and cycling capabilities are limited by the intrinsic (de-)alloying mechanism. Here, we demonstrate a unique surface redox molecular-level mechanism of P sites on oxidized black phosphorus nanosheets that are strongly coupled with graphene via strong interlayer bonding. These redox-active sites of the oxidized black phosphorus are confined at the amorphorized heterointerface, revealing truly reversible pseudocapacitance (99% of total stored charge at 2,000 mV s-1). Moreover, oxidized black-phosphorus-based electrodes exhibit a capacitance of 478 F g-1 (four times greater than black phosphorus) with a rate capability of ~72% (compared to 21.2% for black phosphorus) and retention of ~91% over 50,000 cycles. In situ spectroelectrochemical and theoretical analyses reveal a reversible change in the surface electronic structure and chemical environment of the surface-exposed P redox sites.
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Affiliation(s)
- Puritut Nakhanivej
- School of Chemical Engineering, College of Engineering, Sungkyunkwan University, Suwon, Republic of Korea
| | - Xu Yu
- School of Chemical Engineering, College of Engineering, Sungkyunkwan University, Suwon, Republic of Korea
- School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou, China
| | - Sul Ki Park
- School of Chemical Engineering, College of Engineering, Sungkyunkwan University, Suwon, Republic of Korea
| | - Soo Kim
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL, USA
- Research and Technology Center, Robert Bosch LLC, Cambridge, MA, USA
| | - Jin-Yong Hong
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
- Carbon Industry Frontier Research Center, Korea Research Institute of Chemical Technology (KRICT), Daejeon, Republic of Korea
| | - Hae Jin Kim
- Division of Material Science, Korea Basic Science Institute, Daejeon, Republic of Korea
| | - Wonki Lee
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology (KIST), Wanju, Republic of Korea
| | - Jun Yeon Hwang
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology (KIST), Wanju, Republic of Korea
| | - Ji Eun Yang
- Department of Materials Science & Metallurgy, University of Cambridge, Cambridge, UK
| | - Chris Wolverton
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL, USA
| | - Jing Kong
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Manish Chhowalla
- Department of Materials Science & Metallurgy, University of Cambridge, Cambridge, UK
| | - Ho Seok Park
- School of Chemical Engineering, College of Engineering, Sungkyunkwan University, Suwon, Republic of Korea.
- SKKU Advanced Institute of Nanotechnology (SAINT), College of Engineering & Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences and Technology (SAIHST), Sungkyunkwan University, Suwon, Republic of Korea.
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22
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Sohn HM, Baik JS, Hwang JY, Kim SY, Han SH, Kim JH. Devising negative pressure within intercuff space reduces microaspiration. BMC Anesthesiol 2018; 18:181. [PMID: 30509183 PMCID: PMC6278018 DOI: 10.1186/s12871-018-0643-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2018] [Accepted: 11/20/2018] [Indexed: 02/07/2023] Open
Abstract
Background Microaspiration past the tracheal tube cuffs causes ventilator-associated pneumonia. The objective of the current study was to evaluate whether creating negative pressure between the tracheal double cuffs could block the fluid passage past the tracheal tube cuffs. Methods A new negative pressure system was devised between the double cuffs through a suction hole in the intercuff space. Blue-dyed water was instilled above the cuff at negative suction pressures of − 54, − 68, − 82, − 95, − 109, − 122, and − 136 cmH2O, and the volume leaked was measured in an underlying water trap after 10 min. Leakage tests were also performed during positive pressure ventilation, and using higher-viscosity materials. The actual negative pressures delivered at the hole of double cuffs were obtained by placing microcatheter tip between the intercuff space and the artificial trachea. Results No leakage occurred past the double cuff at − 136 cmH2O suction pressure at all tracheal tube cuff pressures. The volume leaked decreased significantly as suction pressure increased. When connected to a mechanical ventilator, no leakage was found at − 54 cmH2suction pressure. Volume of the higher-viscosity materials (dynamic viscosity of 63–108 cP <cP> and 370–430 cP) leaked was small compared to that of normal saline (0.9–1.1 cP). The pressures measured in the intercuff space corresponded to 3.8–5.9% of those applied. Conclusions A new prototype double cuff with negative pressure in the intercuff space completely prevented water leakage. The negative pressure transmitted to the tracheal inner wall was a small percentage of that applied.
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Affiliation(s)
- H M Sohn
- Department of Anesthesiology and Pain Medicine, Seoul National University Bundang Hospital, Gyeonggi-do, Republic of Korea
| | - J S Baik
- Department of Anesthesiology and Pain Medicine, Pusan National University Hospital, Busan, Republic of Korea
| | - J Y Hwang
- Department of Anesthesiology and Pain Medicine, SMG-SNU Boramae Medical Center, Seoul, Republic of Korea
| | - S Y Kim
- Department of Anesthesiology and Pain Medicine, Seoul National University Bundang Hospital, Gyeonggi-do, Republic of Korea
| | - S H Han
- Department of Anesthesiology and Pain Medicine, Seoul National University Bundang Hospital, Gyeonggi-do, Republic of Korea.,Department of Anesthesiology and Pain Medicine, Seoul National University Medical College, Seoul, Republic of Korea
| | - J H Kim
- Department of Anesthesiology and Pain Medicine, Seoul National University Bundang Hospital, Gyeonggi-do, Republic of Korea. .,Department of Anesthesiology and Pain Medicine, Seoul National University Medical College, Seoul, Republic of Korea.
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Abstract
The extent of dental tissue destruction during the treatment of white spot lesions (WSLs) increases with the severity of the lesion. If the depth and shape of WSLs can be predicted with a noninvasive diagnostic method before dental caries treatment, more conservative interventions can be planned. Given the superiority of high-frequency ultrasound (HFUS) imaging in observing the internal structures of the body, the present study aimed to verify the possibility of HFUS imaging to examine the depth and shape of WSLs. We prepared tooth samples and developed a biomicroscopic system with a HFUS transducer to obtain images of normal and WSL regions. HFUS images were compared with conventional ultrasound images and micro-computed tomography images. HFUS distinctly differentiated demineralization within WSL and normal regions. WSL depth calculated in the micro-computed tomography image was similar to that in HFUS. This study revealed that HFUS imaging has the potential to detect early dental caries and offer information on the invasion depth of early dental caries quantitatively.
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Affiliation(s)
- J Kim
- 1 Department of Information and Communication Engineering, Daegu Gyeongbuk Institute of Science and Technology, Daegu, Republic of Korea
| | - T J Shin
- 2 Department of Pediatric Dentistry, Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - H J Kong
- 3 Department of Biomedical Engineering, College of Medicine, Chungnam National University, and Chungnam National University Hospital, Daejeon, Republic of Korea
| | - J Y Hwang
- 1 Department of Information and Communication Engineering, Daegu Gyeongbuk Institute of Science and Technology, Daegu, Republic of Korea
| | - H K Hyun
- 2 Department of Pediatric Dentistry, Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea
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24
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Hong HJ, Lim JS, Hwang JY, Kim M, Jeong HS, Park MS. Carboxymethlyated cellulose nanofibrils(CMCNFs) embedded in polyurethane foam as a modular adsorbent of heavy metal ions. Carbohydr Polym 2018; 195:136-142. [DOI: 10.1016/j.carbpol.2018.04.081] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 04/16/2018] [Accepted: 04/21/2018] [Indexed: 10/17/2022]
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25
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Chae SS, Jang S, Lee W, Jung DW, Lee KH, Kim JD, Jeong D, Chang H, Hwang JY, Lee JO. Ultrathin Metal Crystals: Growth on Supported Graphene Surfaces and Applications. Small 2018; 14:e1801529. [PMID: 30175531 DOI: 10.1002/smll.201801529] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 05/22/2018] [Indexed: 05/16/2023]
Abstract
Controlled nucleation and growth of metal clusters in metal deposition processes is a long-standing issue for thin-film-based electronic devices. When metal atoms are deposited on solid surfaces, unintended defects sites always lead to a heterogeneous nucleation, resulting in a spatially nonuniform nucleation with irregular growth rates for individual nuclei, resulting in a rough film that requires a thicker film to be deposited to reach the percolation threshold. In the present study, it is shown that substrate-supported graphene promotes the lateral 2D growth of metal atoms on the graphene. Transmission electron microscopy reveals that 2D metallic single crystals are grown epitaxially on supported graphene surfaces while a pristine graphene layer hardly yields any metal nucleation. A surface energy barrier calculation based on density functional theory predicts a suppression of diffusion of metal atoms on electronically perturbed graphene (supported graphene). 2D single Au crystals grown on supported graphene surfaces exhibit unusual near-infrared plasmonic resonance, and the unique 2D growth of metal crystals and self-healing nature of graphene lead to the formation of ultrathin, semitransparent, and biodegradable metallic thin films that could be utilized in various biomedical applications.
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Affiliation(s)
- Soo Sang Chae
- Advanced Materials Division, Korea Research Institute of Chemical Technology (KRICT), Daejeon, 34114, Korea
| | - Seunghun Jang
- Center for Molecular Modeling and Simulation, Korea Research Institute of Chemical Technology (KRICT), Daejeon, 34114, Korea
| | - Wonki Lee
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology, Jeonbuk, 55324, Korea
| | - Du Won Jung
- Advanced Materials Division, Korea Research Institute of Chemical Technology (KRICT), Daejeon, 34114, Korea
| | - Keun Ho Lee
- Raphas R&D Centre, Raphas Co. Ltd., Seoul, 07793, Korea
| | - Jung Dong Kim
- Raphas R&D Centre, Raphas Co. Ltd., Seoul, 07793, Korea
| | - Dohyeon Jeong
- Raphas R&D Centre, Raphas Co. Ltd., Seoul, 07793, Korea
| | - Hyunju Chang
- Center for Molecular Modeling and Simulation, Korea Research Institute of Chemical Technology (KRICT), Daejeon, 34114, Korea
| | - Jun Yeon Hwang
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology, Jeonbuk, 55324, Korea
| | - Jeong-O Lee
- Advanced Materials Division, Korea Research Institute of Chemical Technology (KRICT), Daejeon, 34114, Korea
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26
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Park YW, Jeong YH, Hwang JY, Kwack CH, Hwang SJ. P1714Risk stratification for ischemic and bleeding events in patients using a potent P2Y12 inhibitor. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy565.p1714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Y W Park
- Gyeongsang National University Hospital, Jinju, Korea Republic of
| | - Y H Jeong
- Gyeongsang National University Hospital, Jinju, Korea Republic of
| | - J Y Hwang
- Gyeongsang National University Hospital, Jinju, Korea Republic of
| | - C H Kwack
- Gyeongsang National University Hospital, Jinju, Korea Republic of
| | - S J Hwang
- Gyeongsang National University Hospital, Jinju, Korea Republic of
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27
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Kim KH, Jang HG, Kang YM, Kang MG, Park HW, Koh JS, Park JR, Hwang SJ, Hwang JY. P3681Syntax-I score can predict in-hospital mortality among the patients with ST segment elevation myocardial infarction and cardiogenic shock. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy563.p3681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- K H Kim
- Gyeongsang National University Hospital, Cardiology, Jinju, Korea Republic of
| | - H G Jang
- Gyeongsang National University Hospital, Cardiology, Jinju, Korea Republic of
| | - Y M Kang
- Gyeongsang National University Hospital, Cardiology, Jinju, Korea Republic of
| | - M G Kang
- Gyeongsang National University Hospital, Cardiology, Jinju, Korea Republic of
| | - H W Park
- Gyeongsang National University Hospital, Cardiology, Jinju, Korea Republic of
| | - J S Koh
- Gyeongsang National University Hospital, Cardiology, Jinju, Korea Republic of
| | - J R Park
- Gyeongsang National University Hospital, Cardiology, Jinju, Korea Republic of
| | - S J Hwang
- Gyeongsang National University Hospital, Cardiology, Jinju, Korea Republic of
| | - J Y Hwang
- Gyeongsang National University Hospital, Cardiology, Jinju, Korea Republic of
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Park YW, Jeong YH, Kim JH, Sohn SN, Kwack CH, Hwang JY. P810Histologic comparison of intracerebral and intracoronary thrombi. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy564.p810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Y W Park
- Gyeongsang National University Changwon Hospital, Internal Medicine, Changwon, Korea Republic of
| | - Y H Jeong
- Gyeongsang National University Changwon Hospital, Internal Medicine, Changwon, Korea Republic of
| | - J H Kim
- Gyeongsang National University Hospital, Biomedical Research Institute, Jinju, Korea Republic of
| | - S N Sohn
- Hanil Hospital, Neurology, Jinju, Korea Republic of
| | - C H Kwack
- Gyeongsang National University Changwon Hospital, Internal Medicine, Changwon, Korea Republic of
| | - J Y Hwang
- Gyeongsang National University Hospital, Jinju, Korea Republic of
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Kim NI, Sa YJ, Yoo TS, Choi SR, Afzal RA, Choi T, Seo YS, Lee KS, Hwang JY, Choi WS, Joo SH, Park JY. Oxygen-deficient triple perovskites as highly active and durable bifunctional electrocatalysts for oxygen electrode reactions. Sci Adv 2018; 4:eaap9360. [PMID: 29951583 PMCID: PMC6018999 DOI: 10.1126/sciadv.aap9360] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 04/27/2018] [Indexed: 05/15/2023]
Abstract
Highly active and durable bifunctional oxygen electrocatalysts have been of pivotal importance for renewable energy conversion and storage devices, such as unitized regenerative fuel cells and metal-air batteries. Perovskite-based oxygen electrocatalysts have emerged as promising nonprecious metal bifunctional electrocatalysts, yet their catalytic activity and stability still remain to be improved. We report a high-performance oxygen electrocatalyst based on a triple perovskite, Nd1.5Ba1.5CoFeMnO9-δ (NBCFM), which shows superior activity and durability for oxygen electrode reactions to single and double perovskites. When hybridized with nitrogen-doped reduced graphene oxide (N-rGO), the resulting NBCFM/N-rGO catalyst shows further boosted bifunctional oxygen electrode activity (0.698 V), which surpasses that of Pt/C (0.801 V) and Ir/C (0.769 V) catalysts and which, among the perovskite-based electrocatalysts, is the best activity reported to date. The superior catalytic performances of NBCFM could be correlated to its oxygen defect-rich structure, lower charge transfer resistance, and smaller hybridization strength between O 2p and Co 3d orbitals.
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Affiliation(s)
- Nam-In Kim
- Hybrid Materials Center, Department of Nanotechnology and Advanced Materials Engineering, Sejong University, Seoul 05006, Republic of Korea
| | - Young Jin Sa
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
| | - Tae Sup Yoo
- Department of Physics, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Sung Ryul Choi
- Hybrid Materials Center, Department of Nanotechnology and Advanced Materials Engineering, Sejong University, Seoul 05006, Republic of Korea
| | - Rana Arslan Afzal
- Hybrid Materials Center, Department of Nanotechnology and Advanced Materials Engineering, Sejong University, Seoul 05006, Republic of Korea
| | - Taekjib Choi
- Hybrid Materials Center, Department of Nanotechnology and Advanced Materials Engineering, Sejong University, Seoul 05006, Republic of Korea
| | - Young-Soo Seo
- Hybrid Materials Center, Department of Nanotechnology and Advanced Materials Engineering, Sejong University, Seoul 05006, Republic of Korea
| | - Kug-Seung Lee
- Pohang Accelerator Laboratory, Pohang 37673, Republic of Korea
| | - Jun Yeon Hwang
- Carbon Composite Materials Research Center, Institute of Advanced Composite Materials, Korea Institute of Science and Technology Jeonbuk Branch, Jeonbuk 55324, Republic of Korea
| | - Woo Seok Choi
- Department of Physics, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Sang Hoon Joo
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
- Corresponding author. (J.-Y.P.); (S.H.J.)
| | - Jun-Young Park
- Hybrid Materials Center, Department of Nanotechnology and Advanced Materials Engineering, Sejong University, Seoul 05006, Republic of Korea
- Corresponding author. (J.-Y.P.); (S.H.J.)
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Hwang JY, Byun MS, Choe YM, Lee JH, Yi D, Yoon HN, Park IK, Lee YJ, Lee DY. 0249 Association Between Sleep-Wake Cycle And Brain Cortical Thickness In Young Adults. Sleep 2018. [DOI: 10.1093/sleep/zsy061.248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- J Y Hwang
- Seoul National University College of Medicine, Seoul, KOREA, REPUBLIC OF
| | - M S Byun
- Institute of Human Behavioral Medicine, Medical Research Center Seoul National University, Seoul, KOREA, REPUBLIC OF
| | - Y M Choe
- Department of Psychiatry, Ulsan University Hospital, Ulsan, KOREA, REPUBLIC OF
| | - J H Lee
- Department of Psychiatry, Seoul National University Hospital, Seoul, KOREA, REPUBLIC OF
| | - D Yi
- Institute of Human Behavioral Medicine, Medical Research Center Seoul National University, Seoul, KOREA, REPUBLIC OF
| | - H N Yoon
- Department of Biomedical Engineering, Seoul National University College of Medicine, Seoul, KOREA, REPUBLIC OF
| | - I K Park
- Center for Sleep and Chronobiology, Department of Psychiatry, Seoul National University Hospital, Seoul, KOREA, REPUBLIC OF
| | - Y J Lee
- Center for Sleep and Chronobiology, Department of Psychiatry, Seoul National University Hospital, Seoul, KOREA, REPUBLIC OF
| | - D Y Lee
- Department of Psychiatry, Seoul National University Hospital, Seoul, KOREA, REPUBLIC OF
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Lee KH, Han CY, Jang EP, Jo JH, Hong S, Hwang JY, Choi E, Hwang JH, Yang H. Full-color capable light-emitting diodes based on solution-processed quantum dot layer stacking. Nanoscale 2018; 10:6300-6305. [PMID: 29577132 DOI: 10.1039/c8nr00307f] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
To date, most of the studies on quantum dot-light-emitting diodes (QLEDs) have been dedicated to the fabrication of high-efficiency monochromatic devices. However, for the ultimate application of QLEDs to the next-generation display devices, QLEDs should possess a full-color emissivity. In this study, we report the fabrication of all-solution-processed full-color-capable white QLEDs with a standard device architecture, where sequentially stacked blue (B)/green (G)/red (R) quantum dot (QD)-emitting layers (EMLs) are sandwiched by poly(9-vinylcarbazole) as the hole transport layer and ZnO nanoparticles (NPs) as the electron transport layer. To produce interlayer mixing-free, well-defined B/G/R QD layering assemblies via successive spin casting, an ultrathin ZnO NP buffer is inserted between different-colored QD layers. The present full-color-capable white QLED exhibits high device performance with the maximum values of 16 241 cd m-2 for luminance and 6.8% for external quantum efficiency. The promising results indicate that our novel EML design of ZnO NP buffer-mediated QD layer stacking may afford a viable means towards bright, efficient full-color-capable white devices.
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Affiliation(s)
- Ki-Heon Lee
- Department of Materials Science and Engineering, Hongik University, Seoul 04066, Republic of Korea.
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Kwak DH, Ra HS, Yang J, Jeong MH, Lee AY, Lee W, Hwang JY, Lee JH, Lee JS. Recovery Mechanism of Degraded Black Phosphorus Field-Effect Transistors by 1,2-Ethanedithiol Chemistry and Extended Device Stability. Small 2018; 14:1703194. [PMID: 29211321 DOI: 10.1002/smll.201703194] [Citation(s) in RCA: 10] [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] [Received: 09/15/2017] [Revised: 10/19/2017] [Indexed: 06/07/2023]
Abstract
Black phosphorus (BP) has drawn enormous attention for both intriguing material characteristics and electronic and optoelectronic applications. In spite of excellent advantages for semiconductor device applications, the performance of BP devices is hampered by the formation of phosphorus oxide on the BP surface under ambient conditions. It is thus necessary to resolve the oxygen-induced degradation on the surface of BP to recover the characteristics and stability of the devices. To solve this problem, it is demonstrated that a 1,2-ethanedithiol (EDT) treatment is a simple and effective way to remove the bubbles formed on the BP surface. The device characteristics of the degraded BP field-effect transistor (FET) are completely recovered to the level of the pristine cases by the EDT treatment. The underlying principle of bubble elimination on the BP surface by the EDT treatment is systematically analyzed by density functional theory calculation, atomic force microscopy, and X-ray photoelectron spectroscopy analysis. In addition, the performance of the hexagonal boron nitride-protected BP FET is completely retained without changing device characteristics even when exposed to 30 d or more in air. The EDT-induced recovering effect will allow a new route for the optimization of electronic and optoelectronic devices based on BP.
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Affiliation(s)
- Do-Hyun Kwak
- Department of Energy Science and Engineering, DGIST, Daegu, 42988, Republic of Korea
| | - Hyun-Soo Ra
- Department of Energy Science and Engineering, DGIST, Daegu, 42988, Republic of Korea
| | - Jinhoon Yang
- School of Materials Science and Engineering, GIST, Gwangju, 61005, Republic of Korea
| | - Min-Hye Jeong
- Department of Energy Science and Engineering, DGIST, Daegu, 42988, Republic of Korea
| | - A-Young Lee
- Department of Energy Science and Engineering, DGIST, Daegu, 42988, Republic of Korea
| | - Wonki Lee
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology, 92 Chudong-ro, Bongdong-eup, Wanju-gun, Jeonbuk, 55324, Republic of Korea
| | - Jun Yeon Hwang
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology, 92 Chudong-ro, Bongdong-eup, Wanju-gun, Jeonbuk, 55324, Republic of Korea
| | - Joo-Hyoung Lee
- School of Materials Science and Engineering, GIST, Gwangju, 61005, Republic of Korea
| | - Jong-Soo Lee
- Department of Energy Science and Engineering, DGIST, Daegu, 42988, Republic of Korea
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Hwang JY, Lee JY, Cho CW, Choi W, Lee Y, Shim S, Hwang GT. 5-Bromo-4',5'-bis(dimethylamino)fluorescein: Synthesis and Photophysical Studies. Molecules 2018; 23:E219. [PMID: 29361711 PMCID: PMC6017165 DOI: 10.3390/molecules23010219] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 01/10/2018] [Accepted: 01/16/2018] [Indexed: 11/17/2022] Open
Abstract
In this study, three new fluorescein derivatives-5-bromo-4',5'-dinitrofluorescein (BDNF), 5-bromo-4',5'-diaminofluorescein (BDAF), and 5-bromo-4',5'-bis(dimethylamino)fluorescein (BBDMAF)-were synthesized and their pH-dependent protolytic equilibria were investigated. In particular, BBDMAF exhibited pH-dependent fluorescence, showing strong emission only at pH 3-6. BBDMAF bears a bromine moiety and thus, can be used in various cross-coupling reactions to prepare derivatives and take advantage of its unique emission properties. To confirm this, the Suzuki and Sonogashira reactions of BBDMAF with phenylboronic acid and phenylacetylene, respectively, were performed, and the desired products were successfully obtained.
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Affiliation(s)
- Jun Yeon Hwang
- Department of Chemistry and Green-Nano Materials Research Center, Kyungpook National University, Daegu 41566, Korea; (J.Y.H.); (J.-Y.L.); (C.-W.C.)
| | - Jung-Yean Lee
- Department of Chemistry and Green-Nano Materials Research Center, Kyungpook National University, Daegu 41566, Korea; (J.Y.H.); (J.-Y.L.); (C.-W.C.)
| | - Chang-Woo Cho
- Department of Chemistry and Green-Nano Materials Research Center, Kyungpook National University, Daegu 41566, Korea; (J.Y.H.); (J.-Y.L.); (C.-W.C.)
| | - Wonjun Choi
- Department of Chemistry, Sunchon National University, 255 Jungang-ro, Sunchon, Jeonnam 57922, Korea; (W.C.); (Y.L.)
| | - Yejin Lee
- Department of Chemistry, Sunchon National University, 255 Jungang-ro, Sunchon, Jeonnam 57922, Korea; (W.C.); (Y.L.)
| | - Sangdeok Shim
- Department of Chemistry, Sunchon National University, 255 Jungang-ro, Sunchon, Jeonnam 57922, Korea; (W.C.); (Y.L.)
| | - Gil Tae Hwang
- Department of Chemistry and Green-Nano Materials Research Center, Kyungpook National University, Daegu 41566, Korea; (J.Y.H.); (J.-Y.L.); (C.-W.C.)
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Hwang JY, Shim S, Hwang GT. 4′,5′-Bis(dimethylamino)fluorescein Exhibits pH-Dependent Emission Behavior Distinct From That of Fluorescein. ASIAN J ORG CHEM 2017. [DOI: 10.1002/ajoc.201700577] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Jun Yeon Hwang
- Department of Chemistry; Kyungpook National University; 80 Daehakro Bukgu Daegu 41566 Republic of Korea
| | - Sangdeok Shim
- Department of Chemistry; Sunchon National University; 255 Jungang-ro Sunchon Jeonnam 57922 Republic of Korea
| | - Gil Tae Hwang
- Department of Chemistry; Kyungpook National University; 80 Daehakro Bukgu Daegu 41566 Republic of Korea
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Chee SS, Oh C, Son M, Son GC, Jang H, Yoo TJ, Lee S, Lee W, Hwang JY, Choi H, Lee BH, Ham MH. Sulfur vacancy-induced reversible doping of transition metal disulfides via hydrazine treatment. Nanoscale 2017; 9:9333-9339. [PMID: 28463375 DOI: 10.1039/c7nr01883e] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Chemical doping of transition metal dichalcogenides (TMDCs) has drawn significant interest because of its applicability to the modification of electrical and optical properties of TMDCs. This is of fundamental and technological importance for high-efficiency electronic and optoelectronic devices. Here, we present a simple and facile route to reversible and controllable modulation of the electrical and optical properties of WS2 and MoS2via hydrazine doping and sulfur annealing. Hydrazine treatment of WS2 improves the field-effect mobilities, on/off current ratios, and photoresponsivities of the devices. This is due to the surface charge transfer doping of WS2 and the sulfur vacancies formed by its reduction, which result in an n-type doping effect. The changes in the electrical and optical properties are fully recovered when the WS2 is annealed in an atmosphere of sulfur. This method for reversible modulation can be applied to other transition metal disulfides including MoS2, which may enable the fabrication of two-dimensional electronic and optoelectronic devices with tunable properties and improved performance.
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Affiliation(s)
- Sang-Soo Chee
- School of Materials Science and Engineering, Gwangju Institute of Science & Technology (GIST), 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, Republic of Korea.
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Han JT, Jang JI, Cho JY, Hwang JY, Woo JS, Jeong HJ, Jeong SY, Seo SH, Lee GW. Synthesis of nanobelt-like 1-dimensional silver/nanocarbon hybrid materials for flexible and wearable electroncs. Sci Rep 2017; 7:4931. [PMID: 28694467 PMCID: PMC5504065 DOI: 10.1038/s41598-017-05347-4] [Citation(s) in RCA: 14] [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: 01/26/2017] [Accepted: 05/26/2017] [Indexed: 11/10/2022] Open
Abstract
Most synthetic processes of metallic nanostructures were assisted by organic/inorganic or polymeric materials to control their shapes to one-dimension or two-dimension. However, these additives have to be removed after synthesis of metal nanostructures for applications. Here we report a straightforward method for the low-temperature and additive-free synthesis of nanobelt-like silver nanostructures templated by nanocarbon (NC) materials via bio-inspired shape control by introducing supramolecular 2-ureido-4[1H]pyrimidinone (UPy) groups into the NC surface. The growth of the Ag nanobelt structure was found to be induced by these UPy groups through observation of the selective formation of Ag nanobelts on UPy-modified carbon nanotubes and graphene surfaces. The synthesized NC/Ag nanobelt hybrid materials were subsequently used to fabricate the highly conductive fibres (>1000S/cm) that can function as a conformable electrode and highly tolerant strain sensor, as well as a highly conductive and robust paper (>10000S/cm after thermal treatment).
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Affiliation(s)
- Joong Tark Han
- Nano Hybrid Technology Research Center, Creative and Fundamental Research Division, Korea Electrotechnology Research Institute (KERI), Changwon, 51543, South Korea. .,Department of Electro-Functionality Material Engineering, University of Science and Technology (UST), Changwon, 51543, South Korea.
| | - Jeong In Jang
- Nano Hybrid Technology Research Center, Creative and Fundamental Research Division, Korea Electrotechnology Research Institute (KERI), Changwon, 51543, South Korea
| | - Joon Young Cho
- Department of Electro-Functionality Material Engineering, University of Science and Technology (UST), Changwon, 51543, South Korea
| | - Jun Yeon Hwang
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology (KIST), Eunha-ri san 101, Bondong-eup, Wanju-gun, Jeolabuk-do, 55324, Republic of Korea
| | - Jong Seok Woo
- Nano Hybrid Technology Research Center, Creative and Fundamental Research Division, Korea Electrotechnology Research Institute (KERI), Changwon, 51543, South Korea
| | - Hee Jin Jeong
- Nano Hybrid Technology Research Center, Creative and Fundamental Research Division, Korea Electrotechnology Research Institute (KERI), Changwon, 51543, South Korea
| | - Seung Yol Jeong
- Nano Hybrid Technology Research Center, Creative and Fundamental Research Division, Korea Electrotechnology Research Institute (KERI), Changwon, 51543, South Korea
| | - Seon Hee Seo
- Nano Hybrid Technology Research Center, Creative and Fundamental Research Division, Korea Electrotechnology Research Institute (KERI), Changwon, 51543, South Korea
| | - Geon-Woong Lee
- Nano Hybrid Technology Research Center, Creative and Fundamental Research Division, Korea Electrotechnology Research Institute (KERI), Changwon, 51543, South Korea
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Kim J, Hwang JY, Oh JK, Park MS, Kim SW, Chang H, Kim TH. The association between whole body sagittal balance and risk of falls among elderly patients seeking treatment for back pain. Bone Joint Res 2017; 6:337-344. [PMID: 28536117 PMCID: PMC5457638 DOI: 10.1302/2046-3758.65.bjr-2016-0271.r2] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 03/23/2017] [Indexed: 12/02/2022] Open
Abstract
Objectives The objective of this study was to assess the association between whole body sagittal balance and risk of falls in elderly patients who have sought treatment for back pain. Balanced spinal sagittal alignment is known to be important for the prevention of falls. However, spinal sagittal imbalance can be markedly compensated by the lower extremities, and whole body sagittal balance including the lower extremities should be assessed to evaluate actual imbalances related to falls. Methods Patients over 70 years old who visited an outpatient clinic for back pain treatment and underwent a standing whole-body radiograph were enrolled. Falls were prospectively assessed for 12 months using a monthly fall diary, and patients were divided into fallers and non-fallers according to the history of falls. Radiological parameters from whole-body radiographs and clinical data were compared between the two groups. Results A total of 144 patients (120 female patients and 24 male patients) completed a 12-month follow-up for assessing falls. A total of 31 patients (21.5%) reported at least one fall within the 12-month follow-up. In univariate logistic regression analysis, the risk of falls was significantly increased in older patients and those with more medical comorbidities, decreased lumbar lordosis, increased sagittal vertical axis, and increased horizontal distance between the C7 plumb line and the centre of the ankle (C7A). Increased C7A was significantly associated with increased risk of falls even after multivariate adjustment. Conclusion Whole body sagittal balance, measured by the horizontal distance between the C7 plumb line and the centre of the ankle, was significantly associated with risk of falls among elderly patients with back pain. Cite this article: J. Kim, J. Y. Hwang, J. K. Oh, M. S. Park, S. W. Kim, H. Chang, T-H. Kim. The association between whole body sagittal balance and risk of falls among elderly patients seeking treatment for back pain. Bone Joint Res 2017;6:–344. DOI: 10.1302/2046-3758.65.BJR-2016-0271.R2.
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Affiliation(s)
- J Kim
- Department of Pediatrics, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea
| | - J Y Hwang
- Spine Centre, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang, Korea
| | - J K Oh
- Spine Centre, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang, Korea
| | - M S Park
- Spine Centre, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang, Korea
| | - S W Kim
- Spine Centre, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang, Korea
| | - H Chang
- Spine Centre, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang, Korea
| | - T-H Kim
- Spine Centre, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang, Korea
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Lee JW, Son YS, Hwang JY, Park Y, Hwang GT. pH-Responsive quencher-free molecular beacon systems containing 2′-deoxyuridine units labeled with fluorene derivatives. Org Biomol Chem 2017; 15:7165-7172. [DOI: 10.1039/c7ob01703k] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
pH-Responsive oligodeoxynucleotides only exhibited dramatic increases in fluorescence upon duplex formation with their fully matched target DNAs.
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Affiliation(s)
- Ji Won Lee
- Department of Chemistry
- Kyungpook National University
- Daegu 41566
- Republic of Korea
| | - Ye-Seul Son
- Department of Chemistry
- Kyungpook National University
- Daegu 41566
- Republic of Korea
| | - Jun Yeon Hwang
- Department of Chemistry
- Kyungpook National University
- Daegu 41566
- Republic of Korea
| | - Yoojin Park
- Department of Chemistry
- Division of Advanced Materials Science
- Pohang University of Science and Technology
- Pohang 37673
- Republic of Korea
| | - Gil Tae Hwang
- Department of Chemistry
- Kyungpook National University
- Daegu 41566
- Republic of Korea
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Patel MD, Cha E, Choudhary N, Kang C, Lee W, Hwang JY, Choi W. Vertically oriented MoS 2 nanoflakes coated on 3D carbon nanotubes for next generation Li-ion batteries. Nanotechnology 2016; 27:495401. [PMID: 27827350 DOI: 10.1088/0957-4484/27/49/495401] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The advent of advanced electrode materials has led to performance enhancement of traditional lithium ion batteries (LIBs). We present novel binder-free MoS2 coated three-dimensional carbon nanotubes (3D CNTs) as an anode in LIBs. Scanning transmission electron microscopy analysis shows that vertically oriented MoS2 nanoflakes are strongly bonded to CNTs, which provide a high surface area and active electrochemical sites, and enhanced ion conductivity at the interface. The electrochemical performance shows a very high areal capacity of ~1.65 mAh cm-2 with an areal density of ~0.35 mg cm-2 at 0.5 C rate and coulombic efficiency of ~99% up to 50 cycles. The unique architecture of 3D CNTs-MoS2 is indicative to be a promising anode for next generation Li-ion batteries with high capacity and long cycle life.
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Affiliation(s)
- Mumukshu D Patel
- Department of Materials Science and Engineering, University of North Texas, Denton, TX 76207, USA
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Lee J, Kim T, Jung Y, Jung K, Park J, Lee DM, Jeong HS, Hwang JY, Park CR, Lee KH, Kim SM. High-strength carbon nanotube/carbon composite fibers via chemical vapor infiltration. Nanoscale 2016; 8:18972-18979. [PMID: 27808334 DOI: 10.1039/c6nr06479e] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
In this study, we have developed an efficient and scalable method for improving the mechanical properties of carbon nanotube (CNT) fibers. The mechanical properties of as-synthesized CNT fibers are primarily limited by their porous structures and the weak bonding between adjacent CNTs. These result in inefficient load transfer, leading to low tensile strength and modulus. In order to overcome these limitations, we have adopted chemical vapor infiltration (CVI) to efficiently fill the internal voids of the CNT fibers with carbon species which are thermally decomposed from gas phase hydrocarbon. Through the optimization of the processing time, temperature, and gas flow velocity, we have confirmed that carbon species formed by the thermal decomposition of acetylene (C2H2) gas successfully infiltrated into porous CNT fibers and densified them at relatively low temperatures (650-750 °C). As a result, after CVI processing of the as-synthesized CNT fibers under optimum conditions, the tensile strength and modulus increased from 0.6 GPa to 1.7 GPa and from 25 GPa to 127 GPa, respectively. The CVI technique, combined with the direct spinning of CNT fibers, can open up a route to the fast and scalable fabrication of high performance CNT/C composite fibers. In addition, the CVI technique is a platform technology that can be easily adapted into other nano-carbon based yarn-like fibers such as graphene fibers.
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Affiliation(s)
- Jaegeun Lee
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology, 92 Chudong-ro, Bongdong-eup, Wanju-gun, Jeonbuk 55324, South Korea.
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Kim HY, Lee JW, Oh HM, Baeg KJ, Jung S, Yang HS, Lee W, Hwang JY, Kim KS, Jeong SY, Han JT, Jeong MS, Lee GW, Jeong HJ. Ultrafast Heating for Intrinsic Properties of Atomically Thin Two-Dimensional Materials on Plastic Substrates. ACS Appl Mater Interfaces 2016; 8:31222-31230. [PMID: 27778509 DOI: 10.1021/acsami.6b09677] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Despite recent progress in producing flexible and stretchable electronics based on two-dimensional (2D) nanosheets, their intrinsic properties are often degraded by the presence of polymeric residues that remain attached to the 2D nanosheet surfaces following fabrication. Further breakthroughs are therefore keenly awaited to obtain clean surfaces compatible with flexible applications. Here, we report a method that allows the 2D nanosheets to be intrinsically integrated onto flexible substrates. The method involves thermal decomposition of polymeric residues by microwave-induced ultrafast heating of the surface without affecting the underlying flexible substrate. Mapping the C═O stretching mode by Fourier-transform infrared spectroscopy in combination with atomic force microscopy confirms elimination of the polymeric residues from the 2D nanosheet surface. Flexible devices prepared using microwave-cleaned 2D nanosheets show enhanced electrical, optical, and electrothermal performances. This simple technique is applicable to a wide range of 2D nanomaterials and represents an important advance in the field of flexible devices.
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Affiliation(s)
- Ho Young Kim
- Nano Carbon Materials Research Group, Korea Electrotechnology Research Institute , Changwon 641-120, Korea
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Sungkyunkwan University , Suwon 440-746, Korea
| | - Jae-Won Lee
- Nano Carbon Materials Research Group, Korea Electrotechnology Research Institute , Changwon 641-120, Korea
- Department of Physics, Pusan National University , Busan 609-735, Korea
| | - Hye Min Oh
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Sungkyunkwan University , Suwon 440-746, Korea
| | - Kang-Jun Baeg
- Nano Carbon Materials Research Group, Korea Electrotechnology Research Institute , Changwon 641-120, Korea
| | - Sunshin Jung
- Nano Carbon Materials Research Group, Korea Electrotechnology Research Institute , Changwon 641-120, Korea
| | - Ho-Soon Yang
- Department of Physics, Pusan National University , Busan 609-735, Korea
| | - Wonki Lee
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology , Jeonbuk 565-905, Korea
| | - Jun Yeon Hwang
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology , Jeonbuk 565-905, Korea
| | - Keun Soo Kim
- Department of Physics and Graphene Research Institute, Sejong University , Seoul 05006, Korea
| | - Seung Yol Jeong
- Nano Carbon Materials Research Group, Korea Electrotechnology Research Institute , Changwon 641-120, Korea
| | - Joong Tark Han
- Nano Carbon Materials Research Group, Korea Electrotechnology Research Institute , Changwon 641-120, Korea
| | - Mun Seok Jeong
- Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Sungkyunkwan University , Suwon 440-746, Korea
| | - Geon-Woong Lee
- Nano Carbon Materials Research Group, Korea Electrotechnology Research Institute , Changwon 641-120, Korea
| | - Hee Jin Jeong
- Nano Carbon Materials Research Group, Korea Electrotechnology Research Institute , Changwon 641-120, Korea
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42
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Park TE, Hwang JY, Lim JS, Yun YH. SiC powders synthesized from rice husk. Journal of the Korean Crystal Growth and Crystal Technology 2016. [DOI: 10.6111/jkcgct.2016.26.5.188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Affiliation(s)
- Youngyong Kim
- Department of Chemistry; Research Institute of Natural Science, Gyeongsang National University; Jinju 660-701 Republic of Korea
| | - Kyeongmun Jung
- Department of Chemistry; Research Institute of Natural Science, Gyeongsang National University; Jinju 660-701 Republic of Korea
| | - Jun Yeon Hwang
- Institute of Advanced Composite Materials; Korea Institute of Science and Technology; Jeonbuk 565-950 Republic of Korea
| | - Seokhoon Ahn
- Institute of Advanced Composite Materials; Korea Institute of Science and Technology; Jeonbuk 565-950 Republic of Korea
| | - Ki-Young Kwon
- Department of Chemistry; Research Institute of Natural Science, Gyeongsang National University; Jinju 660-701 Republic of Korea
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44
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Jeong S, Lee J, Kim HC, Hwang JY, Ku BC, Zakharov DN, Maruyama B, Stach EA, Kim SM. Direct observation of morphological evolution of a catalyst during carbon nanotube forest growth: new insights into growth and growth termination. Nanoscale 2016; 8:2055-2062. [PMID: 26700058 DOI: 10.1039/c5nr05547d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
In this study, we develop a new methodology for transmission electron microscopy (TEM) analysis that enables us to directly investigate the interface between carbon nanotube (CNT) arrays and the catalyst and support layers for CNT forest growth without any damage induced by a post-growth TEM sample preparation. Using this methodology, we perform in situ and ex situ TEM investigations on the evolution of the morphology of the catalyst particles and observe the catalyst particles to climb up through CNT arrays during CNT forest growth. We speculate that the lifted catalysts significantly affect the growth and growth termination of CNT forests along with Ostwald ripening and sub-surface diffusion. Thus, we propose a modified growth termination model which better explains various phenomena related to the growth and growth termination of CNT forests.
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Affiliation(s)
- Seojeong Jeong
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology, Jeonbuk 565-905, Republic of Korea. and Department of Organic Materials and Fiber Engineering, Chonbuk National University, Jeonbuk 561-756, Republic of Korea
| | - Jaegeun Lee
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology, Jeonbuk 565-905, Republic of Korea.
| | - Hwan-Chul Kim
- Department of Organic Materials and Fiber Engineering, Chonbuk National University, Jeonbuk 561-756, Republic of Korea
| | - Jun Yeon Hwang
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology, Jeonbuk 565-905, Republic of Korea.
| | - Bon-Cheol Ku
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology, Jeonbuk 565-905, Republic of Korea.
| | - Dmitri N Zakharov
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY 11733, USA
| | - Benji Maruyama
- Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson Air Force Base, OH 45433, USA
| | - Eric A Stach
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY 11733, USA
| | - Seung Min Kim
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology, Jeonbuk 565-905, Republic of Korea.
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45
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Park OK, Kim HJ, Hwang JY, Lee DS, Koo J, Lee H, Yu JS, Ku BC, Lee JK. Synthesis and mechanistic study of in situ halogen/nitrogen dual-doping in graphene tailored by stepwise pyrolysis of ionic liquids. Nanotechnology 2015; 26:115601. [PMID: 25706065 DOI: 10.1088/0957-4484/26/11/115601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
New halogen/nitrogen dual-doped graphenes (X/N-G) with thermally tunable doping levels are synthesized via the thermal reduction of graphite oxide (GO) with stepwise-pyrolyzed ionic liquids. The doping process of halogen and nitrogen into the graphene lattice proceeds via substitutional or covalent bonding through the physisorption or chemisorption of in situ pyrolyzed dopant precursors. The doping process is performed by heating to 300-400 °C of ionic liquid, and the chemically assisted reduction of GO is facilitated by ionic iodine, resulting in I/N-G materials possessing about three and two orders of magnitude higher conductivity (∼22,200 S m(-1)) and charge carrier density (∼10(21) cm(-3)), compared to those of thermally reduced GO. The thermally tunable doping levels of halogen in X/N-G significantly increase the conductivity of doped graphene to ∼27,800 S m(-1).
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Affiliation(s)
- Ok-Kyung Park
- Carbon Convergence Materials Research Center, Institute of Advanced Composite Materials, Korea Institute of Science and Technology (KIST), Jeonbuk 565-902, Korea
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46
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Kim JH, Lee KH, Kang HD, Park B, Hwang JY, Jang HS, Do YR, Yang H. Fabrication of a white electroluminescent device based on bilayered yellow and blue quantum dots. Nanoscale 2015; 7:5363-5370. [PMID: 25721494 DOI: 10.1039/c5nr00426h] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Until now most work on colloidal quantum dot-light-emitting diodes (QLEDs) has been focused on the improvement of the electroluminescent (EL) performance of monochromatic devices, and multi-colored white QLEDs comprising more than one type of QD emitter have been rarely investigated. To demonstrate a white EL as a result of color mixing between blue and yellow, herein a unique combination of two dissimilar QDs of blue- CdZnS/ZnS plus a yellow-emitting Cu-In-S (CIS)/ZnS is used for the formation of the emitting layer (EML) of a multilayered QLED. First, the QLED consisting of a single EML randomly mixed with two QDs is fabricated, however, its EL is dominated by blue emission with the contribution of yellow emission substantially weaker. Thus, another EML configuration is devised in the form of a QD bilayer with two stacking sequences of CdZnS/ZnS//CIS/ZnS QD and vice versa. The QLED with the former stacking sequence shows an overwhelming contribution of blue EL, similar to the mixed QD EML-based device. Upon applying the oppositely stacked QD bilayer of CIS/ZnS//CdZnS/ZnS, however, a bicolored white EL can be successfully achieved by means of the effective extension of the radiative excitonic recombination zone throughout both QD EML regions. Such QD EML configuration-dependent EL results, which are discussed primarily using the proposed device energy level diagram, strongly suggest that the positional design of individual QD emitters is a critical factor for the realization of multicolored, white emissive devices.
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Affiliation(s)
- Jong-Hoon Kim
- Department of Materials Science and Engineering, Hongik University, Seoul 121-791, Korea.
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Park OK, Kim HJ, Hwang JY, Kim SM, Jeong Y, Lee JK, Ku BC. Effects of nitrogen doping from pyrolyzed ionic liquid in carbon nanotube fibers: enhanced mechanical and electrical properties. Nanotechnology 2015; 26:075706. [PMID: 25629600 DOI: 10.1088/0957-4484/26/7/075706] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Nitrogen doping in carbon nanotube (CNT) fibers using pyrolyzed ionic liquid induced interfacial hydrogen bonding between individual CNTs, enhancing mechanical properties and electrical conductivity simultaneously. In particular, the nitrogen doped CNT fiber using the ionic liquid BMI-I exhibited about 104%, 714%, and 38% increased tensile strength (0.65 N/tex), elastic modulus (83 N/tex), and electrical conductivity (1350 S cm(-1)), respectively, compared to pristine CNT fiber.
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Affiliation(s)
- Ok-Kyung Park
- Carbon Convergence Materials Research Center, Institute of Advanced Composite Materials, Korea Institute of Science and Technology (KIST), Jeonbuk 565-902, Korea
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48
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Kim CH, Kim MS, Kim YA, Yang KS, Baek SJ, Lee YJ, Yang CM, Lee YJ, Hwang JY. Electro-conductively deposited carbon fibers for power controllable heating elements. RSC Adv 2015. [DOI: 10.1039/c5ra01296a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Carbon fibers are considered as one of the promising heating elements in various industrial applications because of their excellent thermal stability and electrical conductivity.
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Affiliation(s)
- Chang Hyo Kim
- Department of Polymer Engineering
- Graduate School
- Chonnam National University
- Buk-gu
- Korea
| | - Moo Sung Kim
- Department of Polymer Engineering
- Graduate School
- Chonnam National University
- Buk-gu
- Korea
| | - Yoong Ahm Kim
- Department of Polymer Engineering
- Graduate School
- Chonnam National University
- Buk-gu
- Korea
| | - Kap Seung Yang
- Department of Polymer Engineering
- Graduate School
- Chonnam National University
- Buk-gu
- Korea
| | | | | | - Cheol-Min Yang
- Institute of Advanced Composite Materials
- Korea Institute of Science and Technology (KIST)
- Wanju-gun
- Korea
| | - Yang Jin Lee
- Institute of Advanced Composite Materials
- Korea Institute of Science and Technology (KIST)
- Wanju-gun
- Korea
| | - Jun Yeon Hwang
- Institute of Advanced Composite Materials
- Korea Institute of Science and Technology (KIST)
- Wanju-gun
- Korea
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49
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Abstract
Two-dimensional MoS2 is a promising material for next-generation electronic and optoelectronic devices due to its unique electrical and optical properties including the band gap modulation with film thickness. Although MoS2 has shown excellent properties, wafer-scale production with layer control from single to few layers has yet to be demonstrated. The present study explored the large-scale and thickness-modulated growth of atomically thin MoS2 on Si/SiO2 substrates using a two-step sputtering-CVD method. Our process exhibited wafer-scale fabrication and successful thickness modulation of MoS2 layers from monolayer (0.72 nm) to multilayer (12.69 nm) with high uniformity. Electrical measurements on MoS2 field effect transistors (FETs) revealed a p-type semiconductor behavior with much higher field effect mobility and current on/off ratio as compared to previously reported CVD grown MoS2-FETs and amorphous silicon (a-Si) thin film transistors. Our results show that sputter-CVD is a viable method to synthesize large-area, high-quality, and layer-controlled MoS2 that can be adapted in conventional Si-based microfabrication technology and future flexible, high-temperature, and radiation hard electronics/optoelectronics.
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Affiliation(s)
- Nitin Choudhary
- Department of Materials Science and Engineering, University of North Texas , Denton, Texas 76207, United States
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50
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Han JT, Jang JI, Kim H, Hwang JY, Yoo HK, Woo JS, Choi S, Kim HY, Jeong HJ, Jeong SY, Baeg KJ, Cho K, Lee GW. Extremely efficient liquid exfoliation and dispersion of layered materials by unusual acoustic cavitation. Sci Rep 2014; 4:5133. [PMID: 24875584 PMCID: PMC4038810 DOI: 10.1038/srep05133] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 05/14/2014] [Indexed: 11/09/2022] Open
Abstract
Layered materials must be exfoliated and dispersed in solvents for diverse applications. Usually, highly energetic probe sonication may be considered to be an unfavourable method for the less defective exfoliation and dispersion of layered materials. Here we show that judicious use of ultrasonic cavitation can produce exfoliated transition metal dichalcogenide nanosheets extraordinarily dispersed in non-toxic solvent by minimising the sonolysis of solvent molecules. Our method can also lead to produce less defective, large graphene oxide nanosheets from graphite oxide in a short time (within 10 min), which show high electrical conductivity (>20,000 S m−1) of the printed film. This was achieved by adjusting the ultrasonic probe depth to the liquid surface to generate less energetic cavitation (delivered power ~6 W), while maintaining sufficient acoustic shearing (0.73 m s−1) and generating additional microbubbling by aeration at the liquid surface.
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Affiliation(s)
- Joong Tark Han
- 1] Multidimensional Nanomaterials Research Group, Korea Electrotechnology Research Institute (KERI), Changwon 642-120, Republic of Korea [2] Department of Electrical Functionality Material Engineering, Korea University of Science and Technology (UST), Daejon, 305-333, Republic of Korea
| | - Jeong In Jang
- Multidimensional Nanomaterials Research Group, Korea Electrotechnology Research Institute (KERI), Changwon 642-120, Republic of Korea
| | - Haena Kim
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 790-784, Republic of Korea
| | - Jun Yeon Hwang
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology (KIST), Eunha-ri san 101, Bondong-eup, Wanju-gun, Jeolabuk-do, 565-905, Republic of Korea
| | - Hyung Keun Yoo
- Nanophotonics Laboratory, Advanced Photonics Research Institute, 123 Cheomdan-gwagiro, Buk-gu, Gwangju 500-712, Republic of Korea
| | - Jong Seok Woo
- Nano Carbon Materials Research Group, Korea Electrotechnology Research Institute (KERI), Changwon 642-120, Republic of Korea
| | - Sua Choi
- Nano Carbon Materials Research Group, Korea Electrotechnology Research Institute (KERI), Changwon 642-120, Republic of Korea
| | - Ho Young Kim
- Nano Carbon Materials Research Group, Korea Electrotechnology Research Institute (KERI), Changwon 642-120, Republic of Korea
| | - Hee Jin Jeong
- Nano Carbon Materials Research Group, Korea Electrotechnology Research Institute (KERI), Changwon 642-120, Republic of Korea
| | - Seung Yol Jeong
- Nano Carbon Materials Research Group, Korea Electrotechnology Research Institute (KERI), Changwon 642-120, Republic of Korea
| | - Kang-Jun Baeg
- Nano Carbon Materials Research Group, Korea Electrotechnology Research Institute (KERI), Changwon 642-120, Republic of Korea
| | - Kilwon Cho
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 790-784, Republic of Korea
| | - Geon-Woong Lee
- Nano Carbon Materials Research Group, Korea Electrotechnology Research Institute (KERI), Changwon 642-120, Republic of Korea
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