1
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Cho J, Medina A, Saih I, Il Choi J, Drexler M, Goddard WA, Alamgir FM, Jang SS. 2D Metal/Graphene and 2D Metal/Graphene/Metal Systems for Electrocatalytic Conversion of CO 2 to Formic Acid. Angew Chem Int Ed Engl 2024; 63:e202320268. [PMID: 38271278 DOI: 10.1002/anie.202320268] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Accepted: 01/24/2024] [Indexed: 01/27/2024]
Abstract
Efficiently transforming CO2 into renewable energy sources is crucial for decarbonization efforts. Formic acid (HCOOH) holds great promise as a hydrogen storage compound due to its high hydrogen density, non-toxicity, and stability under ambient conditions. However, the electrochemical reduction of CO2 (CO2 RR) on conventional carbon black-supported metal catalysts faces challenges such as low stability through dissolution and agglomeration, as well as suffering from high overpotentials and the necessity to overcome the competitive hydrogen evolution reaction (HER). In this study, we modify the physical/chemical properties of metal surfaces by depositing metal monolayers on graphene (M/G) to create highly active and stable electrocatalysts. Strong covalent bonding between graphene and metal is induced by the hybridization of sp and d orbitals, especially the sharpd z 2 ${{d}_{{z}^{2}}}$ ,d y z ${{d}_{yz}}$ , andd x z ${{d}_{xz}}$ orbitals of metals near the Fermi level, playing a decisive role. Moreover, charge polarization on graphene in M/G enables the deposition of another thin metallic film, forming metal/graphene/metal (M/G/M) structures. Finally, evaluating overpotentials required for CO2 reduction to HCOOH, CO, and HER, we find that Pd/G, Pt/G/Ag, and Pt/G/Au exhibit excellent activity and selectivity toward HCOOH production. Our novel 2D hybrid catalyst design methodology may offer insights into enhanced electrochemical reactions through the electronic mixing of metal and other p-block elements.
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Affiliation(s)
- Jinwon Cho
- School of materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Dr., Atlanta, GA 30332-0245, USA
| | - Arturo Medina
- School of materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Dr., Atlanta, GA 30332-0245, USA
| | - Ines Saih
- School of materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Dr., Atlanta, GA 30332-0245, USA
| | - Ji Il Choi
- School of materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Dr., Atlanta, GA 30332-0245, USA
| | - Matthew Drexler
- School of materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Dr., Atlanta, GA 30332-0245, USA
| | - William A Goddard
- Materials and Process Simulation Center, California Institute of Technology, Pasadena, CA 91125, USA
| | - Faisal M Alamgir
- School of materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Dr., Atlanta, GA 30332-0245, USA
| | - Seung Soon Jang
- School of materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Dr., Atlanta, GA 30332-0245, USA
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2
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Abdelhafiz A, Choi JI, Zhao B, Cho J, Ding Y, Soule L, Jang SS, Liu M, Alamgir FM. Catalysis Sans Catalyst Loss: The Origins of Prolonged Stability of Graphene-Metal-Graphene Sandwich Architecture for Oxygen Reduction Reactions. Adv Sci (Weinh) 2023; 10:e2304616. [PMID: 37863808 DOI: 10.1002/advs.202304616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Revised: 09/01/2023] [Indexed: 10/22/2023]
Abstract
Over the past decades, the design of active catalysts has been the subject of intense research efforts. However, there has been significantly less deliberate emphasis on rationally designing a catalyst system with a prolonged stability. A major obstacle comes from the ambiguity behind how catalyst degrades. Several degradation mechanisms are proposed in literature, but with a lack of systematic studies, the causal relations between degradation and those proposed mechanisms remain ambiguous. Here, a systematic study of a catalyst system comprising of small particles and single atoms of Pt sandwiched between graphene layers, GR/Pt/GR, is studied to unravel the degradation mechanism of the studied electrocatalyst for oxygen reduction reaction(ORR). Catalyst suffers from atomic dissolution under ORR harsh acidic and oxidizing operation voltages. Single atoms trapped in point defects within the top graphene layer on their way hopping through toward the surface of GR/Pt/GR architecture. Trapping mechanism renders individual Pt atoms as single atom catalyst sites catalyzing ORR for thousands of cycles before washed away in the electrolyte. The GR/Pt/GR catalysts also compare favorably to state-of-the-art commercial Pt/C catalysts and demonstrates a rational design of a hybrid nanoarchitecture with a prolonged stability for thousands of operation cycles.
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Affiliation(s)
- Ali Abdelhafiz
- Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, 77 Mass Ave, Cambridge, MA, 02139, USA
| | - Ji Il Choi
- School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, GA, 30332, USA
| | - Bote Zhao
- School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, GA, 30332, USA
| | - Jinwon Cho
- School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, GA, 30332, USA
| | - Yong Ding
- School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, GA, 30332, USA
| | - Luke Soule
- School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, GA, 30332, USA
| | - Seung Soon Jang
- School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, GA, 30332, USA
| | - Meilin Liu
- School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, GA, 30332, USA
| | - Faisal M Alamgir
- School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, GA, 30332, USA
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3
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Chen J, Moon HJ, Kim KI, Choi JI, Narayanan P, Sakwa-Novak MA, Jones CW, Jang SS. Distribution and Transport of CO 2 in Hyperbranched Poly(ethylenimine)-Loaded MCM-41: A Molecular Dynamics Simulation Approach. ACS Appl Mater Interfaces 2023; 15:43678-43690. [PMID: 37681296 PMCID: PMC10520917 DOI: 10.1021/acsami.3c07040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 08/25/2023] [Indexed: 09/09/2023]
Abstract
Fossil fuel use is accelerating climate change, driving the need for efficient CO2 capture technologies. Solid adsorption-based direct air capture (DAC) of CO2 has emerged as a promising mode for CO2 removal from the atmosphere due to its potential for scalability. Sorbents based on porous supports incorporating oligomeric amines in their pore spaces are widely studied. In this study, we investigate the intermolecular interactions and adsorption of CO2 and H2O molecules in hyperbranched poly(ethylenimine) (HB-PEI) functionalized MCM-41 systems to understand the distribution and transport of CO2 and H2O molecules. Density Functional Theory (DFT) is employed to compute the binding energies of CO2 and H2O molecules with HB-PEI and MCM-41 and to develop force field parameters for molecular dynamics (MD) simulations. The MD simulations are performed to examine the distribution and transport of CO2 and H2O molecules as a function of the HB-PEI content. The study finds that an HB-PEI content of approximately 34 wt % is thermodynamically favorable, with an upper limit of HB-PEI loading between 45 and 50 wt %. The distribution of CO2 and H2O molecules is primarily determined by their adsorptive binding energies, for which H2O molecules dominate the occupation of binding sites due to their strong affinity with silanol groups on MCM-41 and amine groups of HB-PEI. The HB-PEI content has a considerable impact on the diffusion of CO2 and H2O molecules. Furthermore, a larger number of water molecules (higher relative humidity) reduces the correlation of CO2 with the MCM-41 pore surface while enhancing the correlation of CO2 with the amine groups of the HB-PEI. Overall, the presence of H2O molecules increases the CO2 correlation with the amine groups and also the CO2 transport within HB-PEI-loaded MCM-41, meaning that the presence of H2O enhances the CO2 capture in the HB-PEI-loaded MCM-41. These findings are consistent with experimental observations of the impact of increasing humidity on CO2 capture while providing new, molecular-level explanations for the macroscopic experimental findings.
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Affiliation(s)
- Junhe Chen
- Computational
NanoBio Technology Laboratory, School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive NW, Atlanta, Georgia 30332-0245, United States
| | - Hyun June Moon
- School
of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, Georgia 30332-0100, United States
| | - Kyung Il Kim
- Computational
NanoBio Technology Laboratory, School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive NW, Atlanta, Georgia 30332-0245, United States
- School
of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, Georgia 30332-0100, United States
| | - Ji Il Choi
- Computational
NanoBio Technology Laboratory, School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive NW, Atlanta, Georgia 30332-0245, United States
| | - Pavithra Narayanan
- School
of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, Georgia 30332-0100, United States
| | - Miles A. Sakwa-Novak
- Global
Thermostat LLC, 10275
E106th Avenue, Brighton, Colorado 80601, United States
| | - Christopher W. Jones
- School
of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, Georgia 30332-0100, United States
| | - Seung Soon Jang
- Computational
NanoBio Technology Laboratory, School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive NW, Atlanta, Georgia 30332-0245, United States
- Strategic
Energy Institute, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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Oh JW, Lee S, Han H, Allam O, Choi JI, Lee H, Jiang W, Jang J, Kim G, Mun S, Lee K, Kim Y, Park JW, Lee S, Jang SS, Park C. Dual-light emitting 3D encryption with printable fluorescent-phosphorescent metal-organic frameworks. Light Sci Appl 2023; 12:226. [PMID: 37696793 PMCID: PMC10495391 DOI: 10.1038/s41377-023-01274-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 08/07/2023] [Accepted: 08/24/2023] [Indexed: 09/13/2023]
Abstract
Optical encryption technologies based on room-temperature light-emitting materials are of considerable interest. Herein, we present three-dimensional (3D) printable dual-light-emitting materials for high-performance optical pattern encryption. These are based on fluorescent perovskite nanocrystals (NCs) embedded in metal-organic frameworks (MOFs) designed for phosphorescent host-guest interactions. Notably, perovskite-containing MOFs emit a highly efficient blue phosphorescence, and perovskite NCs embedded in the MOFs emit characteristic green or red fluorescence under ultraviolet (UV) irradiation. Such dual-light-emitting MOFs with independent fluorescence and phosphorescence emissions are employed in pochoir pattern encryption, wherein actual information with transient phosphorescence is efficiently concealed behind fake information with fluorescence under UV exposure. Moreover, a 3D cubic skeleton is developed with the dual-light-emitting MOF powder dispersed in 3D-printable polymer filaments for 3D dual-pattern encryption. This article outlines a universal principle for developing MOF-based room-temperature multi-light-emitting materials and a strategy for multidimensional information encryption with enhanced capacity and security.
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Affiliation(s)
- Jin Woo Oh
- Department of Materials Science and Engineering, Yonsei University, Seoul, 03722, Republic of Korea
| | - Seokyeong Lee
- Department of Materials Science and Engineering, Yonsei University, Seoul, 03722, Republic of Korea
| | - Hyowon Han
- Department of Materials Science and Engineering, Yonsei University, Seoul, 03722, Republic of Korea
| | - Omar Allam
- The George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, 801 Ferst Drive, Atlanta, GA, 30332-0405, USA
- School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, GA, 30332-0245, USA
| | - Ji Il Choi
- School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, GA, 30332-0245, USA
| | - Hyeokjung Lee
- Department of Materials Science and Engineering, Yonsei University, Seoul, 03722, Republic of Korea
| | - Wei Jiang
- Department of Materials Science and Engineering, Yonsei University, Seoul, 03722, Republic of Korea
| | - Jihye Jang
- Department of Materials Science and Engineering, Yonsei University, Seoul, 03722, Republic of Korea
| | - Gwanho Kim
- Department of Materials Science and Engineering, Yonsei University, Seoul, 03722, Republic of Korea
| | - Seungsoo Mun
- Department of Materials Science and Engineering, Yonsei University, Seoul, 03722, Republic of Korea
| | - Kyuho Lee
- Department of Materials Science and Engineering, Yonsei University, Seoul, 03722, Republic of Korea
| | - Yeonji Kim
- Department of Materials Science and Engineering, Yonsei University, Seoul, 03722, Republic of Korea
| | - Jong Woong Park
- Department of Materials Science and Engineering, Yonsei University, Seoul, 03722, Republic of Korea
| | - Seonju Lee
- Department of Materials Science and Engineering, Yonsei University, Seoul, 03722, Republic of Korea
| | - Seung Soon Jang
- School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, GA, 30332-0245, USA.
| | - Cheolmin Park
- Department of Materials Science and Engineering, Yonsei University, Seoul, 03722, Republic of Korea.
- Spin Convergence Research Center, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea.
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Salim MG, Vasudevan V, Schulman N, Zamani S, Kersey KD, Joshi Y, AlAmer M, Choi JI, Jang SS, Joo YL. Thermoresponsive Conductivity of Graphene-Based Fibers. Small 2023; 19:e2204981. [PMID: 36828800 DOI: 10.1002/smll.202204981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Revised: 02/07/2023] [Indexed: 05/18/2023]
Abstract
Smart materials are versatile material systems which exhibit a measurable response to external stimuli. Recently, smart material systems have been developed which incorporate graphene in order to share on its various advantageous properties, such as mechanical strength, electrical conductivity, and thermal conductivity as well as to achieve unique stimuli-dependent responses. Here, a graphene fiber-based smart material that exhibits reversible electrical conductivity switching at a relatively low temperature (60 °C), is reported. Using molecular dynamics (MD) simulation and density functional theory-based non-equilibrium Green's function (DFT-NEGF) approach, it is revealed that this thermo-response behavior is due to the change in configuration of amphiphilic triblock dispersant molecules occurring in the graphene fiber during heating or cooling. These conformational changes alter the total number of graphene-graphene contacts within the composite material system, and thus the electrical conductivity as well. Additionally, this graphene fiber fabrication approach uses a scalable, facile, water-based method, that makes it easy to modify material composition ratios. In all, this work represents an important step forward to enable complete functional tuning of graphene-based smart materials at the nanoscale while increasing commercialization viability.
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Affiliation(s)
- Muhammad G Salim
- Robert Fredrick Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY, 14853, USA
| | - Vaibhav Vasudevan
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA, 30332-0245, USA
| | - Nicholas Schulman
- Robert Fredrick Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY, 14853, USA
| | - Somayeh Zamani
- Robert Fredrick Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY, 14853, USA
| | - Kyle D Kersey
- Robert Fredrick Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY, 14853, USA
| | - Yash Joshi
- Robert Fredrick Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY, 14853, USA
| | - Mohammed AlAmer
- Robert Fredrick Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY, 14853, USA
| | - Ji Il Choi
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA, 30332-0245, USA
| | - Seung Soon Jang
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA, 30332-0245, USA
| | - Yong Lak Joo
- Robert Fredrick Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY, 14853, USA
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Choi JI, Kweon HY, Lee YL, Lee JH, Lee SY. Efficacy of Silkworm Pupae Extract on Muscle Strength and Mass in Middle-Aged and Older Individuals: A Randomized, Double-Blind, Placebo-Controlled Trial. J Nutr Health Aging 2023; 27:578-585. [PMID: 37498105 DOI: 10.1007/s12603-023-1942-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2023] [Accepted: 06/06/2023] [Indexed: 07/28/2023]
Abstract
OBJECTIVES We investigated the efficacy and safety of silkworm pupae extract (SWP) consumption for 12 weeks on muscle mass and strength in middle-aged and older individuals with relatively low skeletal muscle mass who do regular low-intensity exercise. DESIGN A randomized double-blinded placebo-controlled trial. PARTICIPANTS The study was conducted with 54 participants with relatively low skeletal muscle mass (SMM) (64.4 ± 6.1 years; body mass index, 23.8 ± 2.4 kg/m2). INTERVENTION AND MEASUREMENTS Participants were randomly assigned to one of two groups: 1000 mg of SWP/day plus regular exercise (SWP group, n=27) or placebo plus regular exercise (placebo group, n=27). All participants were required to engage in 30-60 minutes/day of walking for ≥3 days/week for 12 weeks. The primary outcome was knee extension/flexion strength (Nm), measured at the velocity of 60°/s. Secondary outcomes included body composition, biomarkers (creatine kinase and creatinine), handgrip strength, and quality of life questionnaire. RESULTS Both the intention-to-treat (ITT) and per-protocol (PP) analyses revealed no significant impact of SWP on knee strength compared to the placebo group over 12 weeks. On the other hand, the SWP group had significantly greater increases in right-handgrip strength by 1.94 kg (95% CI: 0.08-3.79; p = 0.041) and left-handgrip strength by 1.83 kg (0.25-3.41; p = 0.024) compared to the placebo group in the ITT population, after 12 weeks. Moreover, in the PP population, the SWP group revealed an even greater increase in right-handgrip strength by 2.07 kg (0.15-3. 98; p = 0.035) and left-handgrip strength by 2.21 kg (0.60-3.83; p = 0.008) for the 12-week period. However, this study resulted in a failure to detect significant differences in the body composition, biomarkers, quality of life questionnaire, physical activity, and caloric intake between the groups. None of the participants in the SWP group experienced any significant adverse events. In the placebo group, two participants experienced urticaria and allergic side effects, leading to their withdrawal from the study and two exhibited elevated levels of liver enzyme and increased diastolic blood pressure, respectively at 12 weeks. CONCLUSION SWP, in addition to low-intensity exercise, may enhance handgrip strengths in middle-aged and older adults with relatively lower SMM. Future studies need to use a large sample size over longer periods to validate our findings. This trial was registered at clinicaltrials.gov as NCT04994054.
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Affiliation(s)
- J I Choi
- Sang Yeoup Lee, Family Medicine Clinic, Pusan National University Yangsan Hospital, Yangsan 50612, Republic of Korea, Telephone: +82-55-390-1442, E-mail: , Fax: +82-51-510-8125
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Choi E, Choi JI, Kim Y, Kim YJ, Eum K, Choi Y, Kwon O, Kim M, Choi W, Ji H, Jang SS, Kim DW. Graphene Nanoribbon Hybridization of Zeolitic Imidazolate Framework Membranes for Intrinsic Molecular Separation. Angew Chem Int Ed Engl 2022; 61:e202214269. [DOI: 10.1002/anie.202214269] [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] [Received: 09/27/2022] [Indexed: 11/05/2022]
Affiliation(s)
- Eunji Choi
- Department of Chemical and Biomolecular Engineering Yonsei University Yonsei-ro 50, Seodaemun-gu Seoul 03722 (Republic of Korea
| | - Ji Il Choi
- School of Materials Science and Engineering Georgia Institute of Technology 771 Ferst Drive NW Atlanta USA
| | - Yong‐Jae Kim
- Department of Chemical and Biomolecular Engineering Korea Advanced Institute of Science and Technology Daehak-ro 291, Yuseong-gu Daejeon 34141 (Republic of Korea
| | - Yeong Jae Kim
- Department of Chemical Engineering Soongsil University Sangdo-ro 369, Dongjak-gu Seoul 06978 (Republic of Korea
| | - Kiwon Eum
- Department of Chemical Engineering Soongsil University Sangdo-ro 369, Dongjak-gu Seoul 06978 (Republic of Korea
| | - Yunkyu Choi
- Department of Chemical and Biomolecular Engineering Yonsei University Yonsei-ro 50, Seodaemun-gu Seoul 03722 (Republic of Korea
| | - Ohchan Kwon
- Department of Chemical and Biomolecular Engineering Yonsei University Yonsei-ro 50, Seodaemun-gu Seoul 03722 (Republic of Korea
| | - Minsu Kim
- Department of Chemical and Biomolecular Engineering Yonsei University Yonsei-ro 50, Seodaemun-gu Seoul 03722 (Republic of Korea
| | - Wooyoung Choi
- Department of Chemical and Biomolecular Engineering Yonsei University Yonsei-ro 50, Seodaemun-gu Seoul 03722 (Republic of Korea
| | - Hyungjoon Ji
- Department of Chemical and Biomolecular Engineering Yonsei University Yonsei-ro 50, Seodaemun-gu Seoul 03722 (Republic of Korea
| | - Seung Soon Jang
- School of Materials Science and Engineering Georgia Institute of Technology 771 Ferst Drive NW Atlanta USA
| | - Dae Woo Kim
- Department of Chemical and Biomolecular Engineering Yonsei University Yonsei-ro 50, Seodaemun-gu Seoul 03722 (Republic of Korea
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Choi E, Choi JI, Kim YJ, Kim YJ, Eum K, Choi Y, Kwon O, Kim M, Choi W, Ji H, Jang SS, Kim DW. Graphene Nanoribbon Hybridization of Zeolitic Imidazolate Framework Membranes for Intrinsic Molecular Separation. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202214269] [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: 11/11/2022]
Affiliation(s)
- Eunji Choi
- Yonsei University Chemical and biomolecular engineering KOREA, REPUBLIC OF
| | - Ji Il Choi
- Georgia Institute of Technology School of Materials Science and Engineering KOREA, REPUBLIC OF
| | - Yong-Jae Kim
- Korea Advanced Institute of Science and Technology Chemical and biomolecular engineering KOREA, REPUBLIC OF
| | - Yeong Jae Kim
- Soongsil University Chemical engineering KOREA, REPUBLIC OF
| | - Kiwon Eum
- Soongsil University Chemical engineering KOREA, REPUBLIC OF
| | - Yunkyu Choi
- Yonsei University Chemical and biomolecular engineering KOREA, REPUBLIC OF
| | - Ohchan Kwon
- Yonsei University Chemical and biomolecular engineering KOREA, REPUBLIC OF
| | - Minsu Kim
- Yonsei University Chemical and biomolecular engineering KOREA, REPUBLIC OF
| | - Wooyoung Choi
- Yonsei University Chemical and biomolecular engineering KOREA, REPUBLIC OF
| | - Hyungjoon Ji
- Yonsei University Chemical and biomolecular engineering KOREA, REPUBLIC OF
| | - Seung Soon Jang
- Georgia Institute of Technology Chemical and biomolecular engineering KOREA, REPUBLIC OF
| | - Dae Woo Kim
- Yonsei University GS-Caltex building #309, Department of Chemical and Biomolecular Engineering 03722 Seoul KOREA, REPUBLIC OF
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Jeong J, Choi JI, Kim YG, Choi YY, Min KJ, Roh SY, Shim JM, Kim JS, Kim YH. Late ventricular potential for risk prediction of sudden cardiac death risk: a valuable tool or an unnecessary step? Eur Heart J 2022. [DOI: 10.1093/eurheartj/ehac544.399] [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/Introduction
Signal-averaged electrocardiography (SA-ECG) is a high-resolution electrocardiography that can detect late ventricular potential, which known to be a noninvasive tool for risk stratification of sudden cardiac death (SCD) by predicting reentrant ventricular tachyarrhythmia. There is a paucity of data with SA-ECG on SCD survivors without structural heart disease, whereas majority of previous studies had been focused on post myocardial infarction survivors.
Purpose
This study assessed the clinical utility of SA-ECG as a risk stratification modality for lethal arrhythmic event in patients at risk of SCD without definite structural heart disease.
Methods
Total 629 patients who experienced or had potential risk of SCD were studied with SA-ECG. Among them, 48 patients who were found to have significant structural heart disease were excluded, except arrhythmogenic right ventricular cardiomyopathy. Major arrhythmic event (MAE) was defined as composite of all-cause death, aborted SCD, and sustained VT during any time either before visit of clinic or during follow up period. Syncope and non-sustained VT was defined as non-major arrhythmic event. SA-ECG was defined positive when fulfilling three or more criterion: (1) unfiltered QRS duration ≥114ms, (2) filtered QRS duration ≥114ms, (3) duration of terminal QRS <40uV exceeding 40ms, and (4) root mean square voltage in the terminal 40ms of ≤20ms.
Results
Among total 581 patients, 145 patients with positive SA-ECG showed higher incidence of MAE compared to patients with negative SA-ECG (21.4% vs. 6.7%, OR 3.816 [95% CI 2.208–6.597], p<0.001, Table). As the number of positive SA-ECG criteria increases, incidence of MAE tended to increase sequentially, which was markedly noted from 2 positive to 3 positive criteria (10.7% to 20.8%, p<0.001, Figure). In particular, patient with inherited arrhythmia showed higher rate of positive late potential compared to those with non-inherited arrhythmia (51.0% vs. 19.3%, p<0.001).
Conclusion
This study showed that at least 3 out of 4 diagnostic criteria in SA-ECG can independently predict lethal arrhythmic events and the positive late potential was associated with lethal arrhythmic event that leads to SCD, suggesting risk prediction for SCD using SA-ECG in patients even without structural heart disease including inherited arrhythmias.
Funding Acknowledgement
Type of funding sources: None.
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Affiliation(s)
- J Jeong
- Korea University Anam Hospital , Seoul , Korea (Republic of)
| | - J I Choi
- Korea University Anam Hospital , Seoul , Korea (Republic of)
| | - Y G Kim
- Korea University Anam Hospital , Seoul , Korea (Republic of)
| | - Y Y Choi
- Korea University Anam Hospital , Seoul , Korea (Republic of)
| | - K J Min
- Korea University Anam Hospital , Seoul , Korea (Republic of)
| | - S Y Roh
- Korea University Guro Hospital , Seoul , Korea (Democratic People's Republic of)
| | - J M Shim
- Korea University Anam Hospital , Seoul , Korea (Republic of)
| | - J S Kim
- Korea University Ansan Hospital , Ansan , Korea (Democratic People's Republic of)
| | - Y H Kim
- Korea University Anam Hospital , Seoul , Korea (Republic of)
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10
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Jeong J, Choi JI, Kim YG, Choi YY, Min KJ, Roh SY, Shim JM, Kim JS, Kim YH. Clinical role of genetic testing for overlapping between Brugada syndrome and arrhythmogenic right ventricular cardiomyopathy. Eur Heart J 2022. [DOI: 10.1093/eurheartj/ehac544.367] [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: 11/12/2022] Open
Abstract
Abstract
Background/Introduction
Brugada syndrome (BrS) and arrhythmogenic right ventricular cardiomyopathy (ARVC) are inherited arrhythmias that may predispose to sudden cardiac arrest. Although its pathogenetic mechanisms differ, overlapping features between BrS and ARVC have been demonstrated previously. However, it remains to be determined whether genetic testing for ARVC-related gene is needed in patients with BrS.
Purpose
This study is aimed to analyze genetic profiles of BrS patients using next generation sequencing (NGS) based multigene panel including ARVC related genes.
Methods
Patients who were confirmed as BrS or clinically suspected as BrS with type 2 or 3 Brugada pattern electrocardiography were studied. Genetic testing using NGS panels (Illumina Inc., San Diego, CA, USA) included 30 genetic variants associated with inherited arrhythmia and genetic cardiomyopathy.
Results
Among the total 119 patients from BrS registry, 63 patients were confirmed as BrS and 56 patients were clinically suspected as BrS without fulfilling diagnostic criteria. One-hundred-fourteen patients (95.8%) were male, and mean age of onset was 43.6 year-old. Genetic variants were identified in 25 of 42 patients who received genetic testing. Six out of 25 patients (24.0%) showed ARVC-related genotypes (2 PKP2, 1 DSG2, 1 TMEM43, 1 JUP, and 1 DSP) (Figure 1 and Table 1). None of the patients showed structural or electrocardiographic features that fulfill diagnostic criteria of ARVC. It is notable that ARVC-related genotypes were mostly frequently accounted for BrS patients, following SCN5A and SCN10A.
Conclusion
In the clinic setting, ARVC-related genetic variants were identified in significant proportion of BrS patients, supporting that genetic testing of ARVC-overlapping is needed. This study suggests that follow-up including imaging study should be considered in BrS patients with ARVC-related genotypes to monitor disease progression as ARVC.
Funding Acknowledgement
Type of funding sources: None.
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Affiliation(s)
- J Jeong
- Korea University Anam Hospital , Seoul , Korea (Republic of)
| | - J I Choi
- Korea University Anam Hospital , Seoul , Korea (Republic of)
| | - Y G Kim
- Korea University Anam Hospital , Seoul , Korea (Republic of)
| | - Y Y Choi
- Korea University Anam Hospital , Seoul , Korea (Republic of)
| | - K J Min
- Korea University Anam Hospital , Seoul , Korea (Republic of)
| | - S Y Roh
- Korea University Guro Hospital , Seoul , Korea (Democratic People's Republic of)
| | - J M Shim
- Korea University Anam Hospital , Seoul , Korea (Republic of)
| | - J S Kim
- Korea University Ansan Hospital , Ansan , Korea (Democratic People's Republic of)
| | - Y H Kim
- Korea University Anam Hospital , Seoul , Korea (Republic of)
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11
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Cho J, Choi JI, Jang SS. Structural Transformation of a Multicompartment Micelle Induced by Photo-Switchable Spiropyran–Merocyanine Transition: Dissipative Particle Dynamics Simulation Approach. J Phys Chem B 2022. [DOI: 10.1021/acs.jpcb.2c02269] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Jinwon Cho
- School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Dr., Atlanta, Georgia 30332-0245, United States
| | - Ji Il Choi
- School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Dr., Atlanta, Georgia 30332-0245, United States
| | - Seung Soon Jang
- School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Dr., Atlanta, Georgia 30332-0245, United States
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12
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Cleveland JW, Choi JI, Sekiya RS, Cho J, Moon HJ, Jang SS, Jones CW. Cooperativity in the Aldol Condensation Using Bifunctional Mesoporous Silica-Poly(styrene) MCM-41 Organic/Inorganic Hybrid Catalysts. ACS Appl Mater Interfaces 2022; 14:11235-11247. [PMID: 35229600 DOI: 10.1021/acsami.1c21738] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
This work explores the efficacy of silica/organic hybrid catalysts, where the organic component is built from linear aminopolymers appended to the silica support within the support mesopores. Specifically, the role of molecular weight and polymer chain composition in amine-bearing atom transfer radical polymerization-synthesized poly(styrene-co-2-(4-vinylbenzyl)isoindoline-1,3-dione) copolymers is probed in the aldol condensation of 4-nitrobenzaldehyde and acetone. Controlled polymerization produces protected amine-containing poly(styrene) chains of controlled molecular weight and dispersity, and a grafting-to thiol-ene coupling approach followed by a phthalimide deprotection step are used to covalently tether and activate the polymer hybrid catalysts prior to the catalytic reactions. Site-normalized batch kinetics are used to assess the role of polymer molecular weight and chain composition in the cooperative catalysis. Lower-molecular-weight copolymers are demonstrated to be more active than catalysts built from only molecular organic components or from higher-molecular-weight chains. Molecular dynamics simulations are used to probe the role of polymer flexibility and morphology, whereby it is determined that higher-molecular-weight hybrid structures result in congested pores that inhibit active site cooperativity and the diffusivity of reagents, thus resulting in lower rates during the reaction.
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Affiliation(s)
- Jacob W Cleveland
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Dr., Atlanta, Georgia 30332-0100, United States
| | - Ji Il Choi
- School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Dr., Atlanta, Georgia 30332-0245, United States
| | - Ryoh-Suke Sekiya
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Dr., Atlanta, Georgia 30332-0100, United States
| | - Jinwon Cho
- School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Dr., Atlanta, Georgia 30332-0245, United States
| | - Hyun June Moon
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Dr., Atlanta, Georgia 30332-0100, United States
| | - Seung Soon Jang
- School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Dr., Atlanta, Georgia 30332-0245, United States
| | - Christopher W Jones
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Dr., Atlanta, Georgia 30332-0100, United States
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13
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Park JW, Kwon OS, Shim JM, Yu HT, Kim TH, Uhm JS, Kim JY, Choi JI, Joung BY, Lee MH, Kim YH, Pak HN. Artificial intelligence-predicted poor responders to catheter ablation for atrial fibrillation. Europace 2021. [DOI: 10.1093/europace/euab116.228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Funding Acknowledgements
Type of funding sources: None.
Introduction
Although atrial fibrillation (AF) catheter ablation is effective for rhythm control, in some patients it is hard to maintain sinus rhythm in spite of repeated AF catheter ablation (AFCA) procedures and anti-arrhythmic drugs (AADs). We explored the pre-procedural predictors for poor responders to AFCA and tested whether artificial intelligence (AI) assists the prediction of poor responders in the independent cohort by determining the invasive parameters.
Methods
Among 1,214 patients who underwent AFCA and regular rhythm follow-up for 56.2 ± 33.8 months (59 ± 11 years, 73.5% male, 68.6% paroxysmal AF), we differentiated 92 poor responders defined as those with sustained AF despite repeat AFCAs, AADs, or electrical cardioversion. Using the Youden index, we identified advanced LA remodeling with lower LA voltage under 1.109mV. AI model, which was derived from development cohort using medical record, was applied to predict LA voltage <1.109mV in the independent cohort (n = 634, poor responders = 24) using a grad-cam score.
Results
The patients with lower LA voltage under 1.109mV showed significantly poorer rhythm outcomes (Log-rank p < 0.001). We determined invasive parameter LA voltage by using the multiple variables (age, female sex, AF type, CHA2DS2VASc score, LA dimension, E/em, hemoglobin, PR interval) and achieved relatively good prediction power of AI for LA voltage <1.109mV (AUC = 0.734, sensitivity 0.729, specificity 0.643) in the test cohort. In the independent cohort, the AI model showed good discrimination power for poor responders (AUC 0.751, p < 0.001) by estimating LA voltage, which is an invasive variable. The patients with predicted lower LA voltage (grad-cam score <0) showed poorer rhythm outcome after active rhythm control (Log-rank p < 0.001)
Conclusions
The patients with advanced atrial remodeling with low LA voltage, which can be predicted by an AI, showed significantly higher recurrence of AF after AFCA with AADs or cardioversion. AI may assist to select these poor responder patients before the AFCA procedure. Abstract Figure.
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Affiliation(s)
- JW Park
- Yonsei University Health system, Seoul, Korea (Republic of)
| | - OS Kwon
- Yonsei University Health system, Seoul, Korea (Republic of)
| | - JM Shim
- Korea University, Cardiovascular Center, Seoul, Korea (Republic of)
| | - HT Yu
- Yonsei University Health system, Seoul, Korea (Republic of)
| | - TH Kim
- Yonsei University Health system, Seoul, Korea (Republic of)
| | - JS Uhm
- Yonsei University Health system, Seoul, Korea (Republic of)
| | - JY Kim
- Yonsei University Health system, Seoul, Korea (Republic of)
| | - JI Choi
- Korea University, Cardiovascular Center, Seoul, Korea (Republic of)
| | - BY Joung
- Yonsei University Health system, Seoul, Korea (Republic of)
| | - MH Lee
- Yonsei University Health system, Seoul, Korea (Republic of)
| | - YH Kim
- Korea University, Cardiovascular Center, Seoul, Korea (Republic of)
| | - HN Pak
- Yonsei University Health system, Seoul, Korea (Republic of)
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14
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Nah Y, Allam O, Kim HS, Choi JI, Kim IS, Byun J, Kim SO, Jang SS, Kim DH. Spectral Instability of Layered Mixed Halide Perovskites Results from Anion Phase Redistribution and Selective Hole Injection. ACS Nano 2021; 15:1486-1496. [PMID: 33382600 DOI: 10.1021/acsnano.0c08897] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Despite the ability to precisely tune their bandgap energies, mixed halide perovskites (MHPs) suffer from significant spectral instability, which obstructs their utilization for the rational design of light-emitting diodes. Here, we investigate the origin of the electroluminescence peak shifts in layered MHPs containing bromide and iodide. X-ray diffraction and steady-state absorption measurements prove effective integration of iodide into the cubic lattice and the spatially uniform distribution of halides in the ambient environment. However, the applied electric field during the device operation is found to drive the systematic halide migration. Quantum mechanical density functional theory calculations reveal that the different activation energies required for directional ion hopping lead to the redistribution of anions. In-depth analyses of the electroluminescence spectra indicate that the spectral shifting rate is dependent on the drift velocity of halides. Finally, it is suggested from our study that the dominant red emission is ascribed to the thermodynamically favorable selective hole injection. Our mechanistic study provides insights into the fundamental reason for the spectral instability of devices based on MHPs.
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Affiliation(s)
- Yoonseo Nah
- Division of Chemical Engineering and Materials Science, College of Engineering, Ewha Womans University, 52 Ewhayeodae-gil, Seodaemun-gu, Seoul 03760, Republic of Korea
| | - Omar Allam
- The George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, 801 Ferst Drive, Atlanta, Georgia 30332-0405, United States
- School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, Georgia 30332-0245, United States
| | - Han Seul Kim
- Center for Supercomputing Applications, National Institute of Supercomputing and Networking, Korea Institute of Science and Technology Information, Daejeon 34141, Republic of Korea
| | - Ji Il Choi
- School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, Georgia 30332-0245, United States
| | - In Soo Kim
- Nanophotonics Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Jinwoo Byun
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
- National Creative Research Initiative Center for Multi-Dimensional Directed Nanoscale Assembly, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| | - Sang Ouk Kim
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
- National Creative Research Initiative Center for Multi-Dimensional Directed Nanoscale Assembly, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| | - Seung Soon Jang
- School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, Georgia 30332-0245, United States
| | - Dong Ha Kim
- Division of Chemical Engineering and Materials Science, College of Engineering, Ewha Womans University, 52 Ewhayeodae-gil, Seodaemun-gu, Seoul 03760, Republic of Korea
- Department of Chemistry and Nano Science, Division of Molecular and Life Sciences, College of Natural Sciences, Ewha Womans University, 52, Ewhayeodae-gil, Seodaemun-gu, Seoul 03760, Republic of Korea
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15
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Choi JI, Kim HS, Shin YS, Johnson C, Fomina N, Staley P, Lang C, Jang SS. Electron-Transport Characteristics through Aluminum Oxide (100) and (012) in a Metal-Insulator-Metal Junction System: Density Functional Theory-Nonequilibrium Green Function Approach. ACS Omega 2020; 5:1717-1724. [PMID: 32010846 PMCID: PMC6990641 DOI: 10.1021/acsomega.9b04011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 01/08/2020] [Indexed: 05/29/2023]
Abstract
Al2O3 is commonly used in modern electronic devices because of its good mechanical properties and excellent electrical insulating property. Although fundamental understanding of the electron transport in Al2O3 is essential for its use in electronic device applications, a thorough investigation for the electron-transport mechanism has not been conducted on the structures of Al2O3, especially in nanometer-scale electronic device settings. In this work, electron transport via Al2O3 for two crystallographic facets, (100) and (012), in a metal-insulator-metal junction configuration is investigated using a density functional theory-based nonequilibrium Green function method. First, it is confirmed that the transmission function, T(E), decreases as a function of energy in (E - E F) < 0 regime, which is an intuitively expected trend. On the other hand, in the (E - E F) > 0 regime, Al2O3(100) and Al2O3(012) show their own characteristic behaviors of T(E), presenting that major peaks are shifted toward lower energy levels under a finite bias voltage. Second, the overall conductance decay rates under zero bias are similar regardless of the crystallographic orientation, so that the contact interface seemingly has only a minor contribution to the overall conductance. A noteworthy feature at the finite bias condition is that the electrical current drastically increases as a function of bias potential (>0.7 V) in Al2O3(012)-based junction compared with the Al2O3(100) counterpart. It is elucidated that such a difference is due to the well-developed eigenchannels for electron transport in the Al2O3(012)-based junction. Therefore, it is evidently demonstrated that at finite bias condition, the contact interface plays a key role in determining insulating properties of Al2O3-Pt junctions.
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Affiliation(s)
- Ji Il Choi
- Computational
NanoBio Technology Laboratory, School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive NW, Atlanta, Georgia 30332-0245, United States
| | - Han Seul Kim
- National
Institute of Supercomputing and Networking, Korea Institute of Science and Technology Information, Daejeon 34141, Republic of Korea
| | - Young Shik Shin
- Research
& Technology Center, Robert Bosch LLC, 384 Santa Trinita Avenue, Sunnyvale, California 94085, United States
| | - Christopher Johnson
- Research
& Technology Center, Robert Bosch LLC, 384 Santa Trinita Avenue, Sunnyvale, California 94085, United States
| | - Nadezda Fomina
- Research
& Technology Center, Robert Bosch LLC, 384 Santa Trinita Avenue, Sunnyvale, California 94085, United States
| | - Patrick Staley
- Research
& Technology Center, Robert Bosch LLC, 384 Santa Trinita Avenue, Sunnyvale, California 94085, United States
- School
of Mathematics, Science & Engineering, Southwestern College, 900 Otay Lakes Rd, Chula Vista, California 91910-7297, United States
| | - Christoph Lang
- Research
& Technology Center, Robert Bosch LLC, 384 Santa Trinita Avenue, Sunnyvale, California 94085, United States
| | - Seung Soon Jang
- Computational
NanoBio Technology Laboratory, School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive NW, Atlanta, Georgia 30332-0245, United States
- Institute
for Electronics and Nanotechnology, Georgia
Institute of Technology, Atlanta, Georgia 30332, United States
- Strategic
Energy Institute, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
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16
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Choi CU, Choi JI, Kim W, Jang WY, Kang DO, Park Y, Na JO, Kim EJ, Rha SW, Park CG, Seo HS, Kim JW. P2523Hand grip strength as a predictor of exercise capacity in coronary heart disease. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz748.0852] [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
A recent study has shown that quadriceps strength can be used to predict the level of exercise capacity in patients with coronary heart disease (CHD). We investigated whether the relationship between muscular strength and exercise capacity is also observed with hand grip strength (HGS). We studied 443 participants (age, 61.8±11.2 y; 77.7% male) who underwent coronary intervention and participated in cardiac rehabilitation between 2015 and 2018. Participants were assessed for grip strength, measured using a Jamar dynamometer. Logistic regression was used to assess the relationship between various clinical measures (HGS, age, sex, etc) with the distance walked on a 6-minute walk test (6MWT) and maximal oxygen uptake (VO2max). HGS was significantly related to distance walked on the 6MWT (r=0.435, p<0.001). It was the only predictor of all exercise capacity categories, and one of the strongest predictors of each exercise capacity category. A HGS of 25.5% of body weight predicted an achievement of a 200 m walk on the 6MWT (positive predictive value = 0.95). However, HGS less than 35.5% of body weight predicted that 500m could not be done in 6 minutes (negative predictive value = 0.97). This trend was also observed in the subgroups in which VO2max was measured. This study demonstrates that HGS is associated with exercise capacity in CHD and can be used to predict the level of exercise capacity. These findings may contribute to setting the recommended level of daily activity as well as the level of cardiac rehabilitation in CHD.
Logistic regression models for different levels of exercise capacity Level of exercise capacity B±S.E p-value Odd ratio 95% CI Distance of 6MWT 200 m Grip strength 0.054±0.014 <0.001 1.056 1.027–1.086 300 m Grip strength 0.042±0.009 <0.001 1.042 1.024–1.062 400 m Grip strength 0.047±0.011 <0.001 1.048 1.026–1.070 500 m Grip strength 0.051±0.016 0.001 1.053 1.021–1.086 VO2max level 4 METs Grip strength 0.054±0.010 <0.001 1.056 1.036–1.076 6 METs Grip strength 0.059±0.011 <0.001 1.061 1.039–1.083 8 METs Grip strength 0.081±0.015 <0.001 1.085 1.053–1.117 10 METs Grip strength 0.113±0.049 0.019 1.12 1.019–3.232 Data are presented as mean ± standard deviation (SD). 6MWT, 6-minute walk test; STEMI, ST-Elevation Myocardial Infarction; SE, standard error; CI, confidence interval; VO2max, Maximal Oxygen uptake; METs, Metabolic equivalents.
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Affiliation(s)
- C U Choi
- Korea University Guro Hospital, Cardiology, Seoul, Korea (Republic of)
| | - J I Choi
- Korea University Anam Hospital, Seoul, Korea (Republic of)
| | - W Kim
- Korea University Guro Hospital, Cardiology, Seoul, Korea (Republic of)
| | - W Y Jang
- Korea University Guro Hospital, Cardiology, Seoul, Korea (Republic of)
| | - D O Kang
- Korea University Guro Hospital, Cardiology, Seoul, Korea (Republic of)
| | - Y Park
- Korea University Guro Hospital, Cardiology, Seoul, Korea (Republic of)
| | - J O Na
- Korea University Guro Hospital, Cardiology, Seoul, Korea (Republic of)
| | - E J Kim
- Korea University Guro Hospital, Cardiology, Seoul, Korea (Republic of)
| | - S W Rha
- Korea University Guro Hospital, Cardiology, Seoul, Korea (Republic of)
| | - C G Park
- Korea University Guro Hospital, Cardiology, Seoul, Korea (Republic of)
| | - H S Seo
- Korea University Guro Hospital, Cardiology, Seoul, Korea (Republic of)
| | - J W Kim
- Korea University Guro Hospital, Cardiology, Seoul, Korea (Republic of)
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17
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Park EJ, Kim WH, Choi JY, Jang WY, Na JO, Choi JI, Kim JW, Kim EJ, Rha SW, Park CG, Seo HS, Choi CU. P2690The bleeding and cardiovascular risk according to NSAIDs selectivity in patients receiving antithrombotics and concomitant NSAIDs after myocardial infarction: a nationwide cohort study. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy565.p2690] [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)
- E J Park
- Korea University Guro Hospital, Cardiology, Seoul, Korea Republic of
| | - W H Kim
- Korea University Guro Hospital, Cardiology, Seoul, Korea Republic of
| | - J Y Choi
- Korea University Guro Hospital, Cardiology, Seoul, Korea Republic of
| | - W Y Jang
- Korea University Guro Hospital, Cardiology, Seoul, Korea Republic of
| | - J O Na
- Korea University Guro Hospital, Cardiology, Seoul, Korea Republic of
| | - J I Choi
- Korea University Anam Hospital, Seoul, Korea Republic of
| | - J W Kim
- Korea University Guro Hospital, Cardiology, Seoul, Korea Republic of
| | - E J Kim
- Korea University Guro Hospital, Cardiology, Seoul, Korea Republic of
| | - S W Rha
- Korea University Guro Hospital, Cardiology, Seoul, Korea Republic of
| | - C G Park
- Korea University Guro Hospital, Cardiology, Seoul, Korea Republic of
| | - H S Seo
- Korea University Guro Hospital, Cardiology, Seoul, Korea Republic of
| | - C U Choi
- Korea University Guro Hospital, Cardiology, Seoul, Korea Republic of
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18
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Shim J, Min KJ, Kim YG, Oh SK, Park HS, Lee KN, Choi JI, Kim YH. P861Outcomes of catheter ablation for longstanding persistent atrial fibrillation with unsuccessful electrical cardioversion. Europace 2018. [DOI: 10.1093/europace/euy015.464] [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: 11/12/2022] Open
Affiliation(s)
- J Shim
- Korea University Anam Hospital, Cardiology, Seoul, Korea Republic of
| | - K J Min
- Korea University Anam Hospital, Cardiology, Seoul, Korea Republic of
| | - Y G Kim
- Korea University Anam Hospital, Cardiology, Seoul, Korea Republic of
| | - S K Oh
- Korea University Anam Hospital, Cardiology, Seoul, Korea Republic of
| | - H S Park
- Korea University Anam Hospital, Cardiology, Seoul, Korea Republic of
| | - K N Lee
- Korea University Anam Hospital, Cardiology, Seoul, Korea Republic of
| | - J I Choi
- Korea University Anam Hospital, Cardiology, Seoul, Korea Republic of
| | - Y H Kim
- Korea University Anam Hospital, Cardiology, Seoul, Korea Republic of
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19
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Kim YG, Shim JM, Choi JI, Kim YH. P868Clinical and echocardiographic characteristics associated with future risk of ischemic stroke in atrial fibrillation patients undergoing radio-frequency catheter ablation. Europace 2018. [DOI: 10.1093/europace/euy015.471] [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: 11/14/2022] Open
Affiliation(s)
- Y G Kim
- Korea University Anam Hospital, Cardiovascular Center, Seoul, Korea Republic of
| | - J M Shim
- Korea University Anam Hospital, Cardiovascular Center, Seoul, Korea Republic of
| | - J I Choi
- Korea University Anam Hospital, Cardiovascular Center, Seoul, Korea Republic of
| | - Y H Kim
- Korea University Anam Hospital, Cardiovascular Center, Seoul, Korea Republic of
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20
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Choi JI, Chang AL. Abstract P2-11-09: Excellent acute toxicity outcomes with proton therapy for partial breast irradiation in early stage breast cancer: Initial results of a multi-institutional phase II trial. Cancer Res 2018. [DOI: 10.1158/1538-7445.sabcs17-p2-11-09] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background and Purpose: Partial breast irradiation (PBI) with proton therapy after lumpectomy for early stage invasive breast cancer is an area of active investigation. Advantages of this technique include a shorter treatment course and the potential for decreased morbidity versus external beam photon radiation therapy given superior sparing of the surrounding normal breast tissue. To date, multiple single-institutional studies have reported conflicting results on the acute toxicity of PBI. This prospective phase II trial investigates the feasibility, safety, and efficacy of delivering PBI with proton therapy in a multi-institutional setting.
Methods: Patients over the age of 50 years with ER-positive nonlobular invasive breast cancer or ductal carcinoma in situ ≤3 cm in size who had undergone lumpectomy with at least 2 mm negative surgical margins were treated with proton therapy to a dose of 40 Gy delivered over 10 daily fractions. In this initial analysis, we assess early toxicity and treatment efficacy of proton PBI. Patients were followed up at 4 weeks post-treatment and annually thereafter, along with annual mammograms. Patient-reported quality of life and physician-reported cosmesis assessments including photographs were obtained at 1 and 3 years post-treatment.
Results: Forty patients were enrolled, of which 38 were evaluable. At a median follow-up of 17.8 months (range 2-36 months), all patients had overall breast cosmesis that was scored “good” or “excellent”. Of 6 grade 2 acute adverse events that occurred, only 1 was radiation dermatitis, with others including lymphedema, hot flashes, and fatigue. One grade 3 acute toxicity occurred 3 weeks after radiation completion in the form of vascular disease requiring stent placement, highly unlikely to be attributable to radiation effects. Patient-reported quality of life outcomes were recorded using the standardized Breast Cancer Treatment Outcome Scale (BCTOS) scored from 1-4 (1: none; 2: mild; 3: moderate; 4: large), with endpoints receiving a score of 3 or 4 most frequently involving change in breast size, breast texture, nipple appearance, or scar tissue. Patients assigned a score of 4 for change in nipple appearance (n=2), breast shape (n=2), and scar tissue formation (n=2). To date, local, locoregional, and distant disease control are 100%, although one patient has developed a new hormone receptor-negative invasive ductal carcinoma of the contralateral breast.
Conclusion: Proton PBI provides excellent early cancer control with acceptable cosmetic outcomes and minimal adverse effects as per patient- and physician-reported assessments. On continued follow-up, late toxicity and cosmesis, as well as long-term disease control outcomes, will be assessed.
Citation Format: Choi JI, Chang AL. Excellent acute toxicity outcomes with proton therapy for partial breast irradiation in early stage breast cancer: Initial results of a multi-institutional phase II trial [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-11-09.
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Affiliation(s)
- JI Choi
- Scripps Proton Therapy Center, San Diego, CA; ProCure Oklahoma City, Oklahoma City, OK
| | - AL Chang
- Scripps Proton Therapy Center, San Diego, CA; ProCure Oklahoma City, Oklahoma City, OK
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Kwon S, Kwon HJ, Choi JI, Kim KC, Seo JG, Park JE, You SJ, Park ED, Jang SS, Lee HC. Enhanced Selectivity for CO 2 Adsorption on Mesoporous Silica with Alkali Metal Halide Due to Electrostatic Field: A Molecular Simulation Approach. ACS Appl Mater Interfaces 2017; 9:31683-31690. [PMID: 28829116 DOI: 10.1021/acsami.7b04508] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Since adsorption performances are dominantly determined by adsorbate-adsorbent interactions, accurate theoretical prediction of the thermodynamic characteristics of gas adsorption is critical for designing new sorbent materials as well as understanding the adsorption mechanisms. Here, through our molecular modeling approach using a newly developed quantum-mechanics-based force field, it is demonstrated that the CO2 adsorption selectivity of SBA-15 can be enhanced by incorporating crystalline potassium chloride particles. It is noted that the induced intensive electrostatic fields around potassium chloride clusters create gas-trapping sites with high selectivity for CO2 adsorption. The newly developed force field can provide a reliable theoretical tool for accurately evaluating the gas adsorption on given adsorbents, which can be utilized to identify good gas adsorbents.
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Affiliation(s)
- Soonchul Kwon
- Samsung Advanced Institute of Technology, Samsung Electronics Co., Ltd. , 130 Samsung-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do 443-803, Republic of Korea
- Department of Civil and Environmental Engineering, Pusan National University , 2, Busandaehak-ro 63beon-gil, Geumjeong-gu, Busan 46241, Republic of Korea
| | - Hyuk Jae Kwon
- Samsung Advanced Institute of Technology, Samsung Electronics Co., Ltd. , 130 Samsung-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do 443-803, Republic of Korea
| | - Ji Il Choi
- School of Materials Science and Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332-0245, United States
| | - Ki Chul Kim
- School of Materials Science and Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332-0245, United States
| | - Jeong Gil Seo
- Samsung Advanced Institute of Technology, Samsung Electronics Co., Ltd. , 130 Samsung-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do 443-803, Republic of Korea
- Department of Environmental Engineering and Energy, Myongji University , 116 Myongji-ro, Cheoin-gu, Yongin-si, Gyeonggi-do 449-728, Republic of Korea
| | - Jung Eun Park
- Department of Energy Systems Research and Department of Chemical Engineering, Ajou University , 206, Worldcup-ro, Yeongtong-gu, Suwon 443-749, Republic of Korea
| | - Su Jin You
- Department of Energy Systems Research and Department of Chemical Engineering, Ajou University , 206, Worldcup-ro, Yeongtong-gu, Suwon 443-749, Republic of Korea
| | - Eun Duck Park
- Department of Energy Systems Research and Department of Chemical Engineering, Ajou University , 206, Worldcup-ro, Yeongtong-gu, Suwon 443-749, Republic of Korea
| | - Seung Soon Jang
- School of Materials Science and Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332-0245, United States
| | - Hyun Chul Lee
- Samsung Advanced Institute of Technology, Samsung Electronics Co., Ltd. , 130 Samsung-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do 443-803, Republic of Korea
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Yu YJ, Lee GH, Choi JI, Shim YS, Lee CH, Kang SJ, Lee S, Rim KT, Flynn GW, Hone J, Kim YH, Kim P, Nuckolls C, Ahn S. Epitaxially Self-Assembled Alkane Layers for Graphene Electronics. Adv Mater 2017; 29:1603925. [PMID: 27905154 DOI: 10.1002/adma.201603925] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 10/17/2016] [Indexed: 06/06/2023]
Abstract
The epitaxially grown alkane layers on graphene are prepared by a simple drop-casting method and greatly reduce the environmentally driven doping and charge impurities in graphene. Multiscale simulation studies show that this enhancement of charge homogeneity in graphene originates from the lifting of graphene from the SiO2 surface toward the well-ordered and rigid alkane self-assembled layers.
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Affiliation(s)
- Young-Jun Yu
- ICT Materials and Components Basic Research Group, Electronics and Telecommunications Research Institute (ETRI), Daejeon, 34129, Korea
| | - Gwan-Hyoung Lee
- Department of Materials Science and Engineering, Yonsei University, Seoul, 03722, Korea
| | - Ji Il Choi
- Graduate School of Energy, Environment, Water, and Sustainability, Korea Advanced Institute of Science and Technology, Daejeon, 305-701, Korea
| | - Yoon Su Shim
- Graduate School of Energy, Environment, Water, and Sustainability, Korea Advanced Institute of Science and Technology, Daejeon, 305-701, Korea
| | - Chul-Ho Lee
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, 136-701, Korea
| | - Seok Ju Kang
- School of Energy and Chemical Engineering, UNIST, Ulsan, 689-798, Korea
| | - Sunwoo Lee
- Department of Electrical Engineering, Columbia University, New York, NY, 10027, USA
| | - Kwang Taeg Rim
- Department of Chemistry, Columbia University, New York, NY, 10027, USA
| | - George W Flynn
- Department of Chemistry, Columbia University, New York, NY, 10027, USA
| | - James Hone
- Department of Mechanical Engineering, Columbia University, New York, NY, 10027, USA
| | - Yong-Hoon Kim
- Graduate School of Energy, Environment, Water, and Sustainability, Korea Advanced Institute of Science and Technology, Daejeon, 305-701, Korea
| | - Philip Kim
- Department of Physics, Harvard University, Cambridge, MA, 02138, USA
| | - Colin Nuckolls
- Department of Chemistry, Columbia University, New York, NY, 10027, USA
| | - Seokhoon Ahn
- Institute of Advanced Composite Materials, Korea Institute of Science and Technology, Jeonbuk, 565-905, Korea
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23
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Ju MJ, Jeon IY, Kim HM, Choi JI, Jung SM, Seo JM, Choi IT, Kang SH, Kim HS, Noh MJ, Lee JJ, Jeong HY, Kim HK, Kim YH, Baek JB. Edge-selenated graphene nanoplatelets as durable metal-free catalysts for iodine reduction reaction in dye-sensitized solar cells. Sci Adv 2016; 2:e1501459. [PMID: 27386557 PMCID: PMC4928943 DOI: 10.1126/sciadv.1501459] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 05/23/2016] [Indexed: 05/06/2023]
Abstract
Metal-free carbon-based electrocatalysts for dye-sensitized solar cells (DSSCs) are sufficiently active in Co(II)/Co(III) electrolytes but are not satisfactory in the most commonly used iodide/triiodide (I(-)/I3 (-)) electrolytes. Thus, developing active and stable metal-free electrocatalysts in both electrolytes is one of the most important issues in DSSC research. We report the synthesis of edge-selenated graphene nanoplatelets (SeGnPs) prepared by a simple mechanochemical reaction between graphite and selenium (Se) powders, and their application to the counter electrode (CE) for DSSCs in both I(-)/I3 (-) and Co(II)/Co(III) electrolytes. The edge-selective doping and the preservation of the pristine graphene basal plane in the SeGnPs were confirmed by various analytical techniques, including atomic-resolution transmission electron microscopy. Tested as the DSSC CE in both Co(bpy)3 (2+/3+) (bpy = 2,2'-bipyridine) and I(-)/I3 (-) electrolytes, the SeGnP-CEs exhibited outstanding electrocatalytic performance with ultimately high stability. The SeGnP-CE-based DSSCs displayed a higher photovoltaic performance than did the Pt-CE-based DSSCs in both SM315 sensitizer with Co(bpy)3 (2+/3+) and N719 sensitizer with I(-)/I3 (-) electrolytes. Furthermore, the I3 (-) reduction mechanism, which has not been fully understood in carbon-based CE materials to date, was clarified by an electrochemical kinetics study combined with density functional theory and nonequilibrium Green's function calculations.
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Affiliation(s)
- Myung Jong Ju
- School of Energy and Chemical Engineering, Center for Dimension-Controllable Organic Frameworks, Ulsan National Institute of Science and Technology (UNIST), 50, UNIST, Ulsan 689-798, Korea
| | - In-Yup Jeon
- School of Energy and Chemical Engineering, Center for Dimension-Controllable Organic Frameworks, Ulsan National Institute of Science and Technology (UNIST), 50, UNIST, Ulsan 689-798, Korea
| | - Hong Mo Kim
- Global GET-Future Laboratory and Department of Advanced Materials Chemistry, Korea University, 2511 Sejong-ro, Sejong 339-700, Korea
| | - Ji Il Choi
- Graduate School of Energy, Environment, Water, and Sustainability, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Daejeon 305-701, Korea
| | - Sun-Min Jung
- School of Energy and Chemical Engineering, Center for Dimension-Controllable Organic Frameworks, Ulsan National Institute of Science and Technology (UNIST), 50, UNIST, Ulsan 689-798, Korea
| | - Jeong-Min Seo
- School of Energy and Chemical Engineering, Center for Dimension-Controllable Organic Frameworks, Ulsan National Institute of Science and Technology (UNIST), 50, UNIST, Ulsan 689-798, Korea
| | - In Taek Choi
- Global GET-Future Laboratory and Department of Advanced Materials Chemistry, Korea University, 2511 Sejong-ro, Sejong 339-700, Korea
| | - Sung Ho Kang
- Global GET-Future Laboratory and Department of Advanced Materials Chemistry, Korea University, 2511 Sejong-ro, Sejong 339-700, Korea
| | - Han Seul Kim
- Graduate School of Energy, Environment, Water, and Sustainability, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Daejeon 305-701, Korea
| | - Min Jong Noh
- Graduate School of Energy, Environment, Water, and Sustainability, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Daejeon 305-701, Korea
| | - Jae-Joon Lee
- Department of Energy and Materials Engineering, Dongguk University, 30 Pildong-ro 1-gil, Junggu, Seoul 04620, Korea
| | - Hu Young Jeong
- UNIST Central Research Facilities (UCRF), 50, UNIST, Ulsan 689-798, Korea
| | - Hwan Kyu Kim
- Global GET-Future Laboratory and Department of Advanced Materials Chemistry, Korea University, 2511 Sejong-ro, Sejong 339-700, Korea
- Corresponding author. (J.-B.B.); (Y.-H.K.); (H.K.K.)
| | - Yong-Hoon Kim
- Graduate School of Energy, Environment, Water, and Sustainability, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Daejeon 305-701, Korea
- Corresponding author. (J.-B.B.); (Y.-H.K.); (H.K.K.)
| | - Jong-Beom Baek
- School of Energy and Chemical Engineering, Center for Dimension-Controllable Organic Frameworks, Ulsan National Institute of Science and Technology (UNIST), 50, UNIST, Ulsan 689-798, Korea
- Corresponding author. (J.-B.B.); (Y.-H.K.); (H.K.K.)
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Choi JI, Kim HS, Kim HS, Lee GI, Kang JK, Kim YH. Carbon nanobuds based on carbon nanotube caps: a first-principles study. Nanoscale 2016; 8:2343-2349. [PMID: 26752260 DOI: 10.1039/c5nr07188g] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Based on density functional theory calculations, we here show that the formation of a fullerene C60 carbon "nanobud" (CNB) on carbon nanotube (CNT) caps is energetically more favorable than that on CNT sidewalls. The dominant CNB formation mode for CNT caps is found to be the [2 + 2] cycloaddition reaction as in the conventional CNT sidewall case. However, it is identified to be exothermic in contrast to the endothermic reaction on CNT sidewalls. Computed reaction pathways further demonstrate that the formation (dissociation) barrier for the CNT cap-based CNB is slightly lower (significantly higher) than that of the CNT sidewall-based CNB, indicating an easier CNB formation as well as a higher structural stability. Additionally, performing matrix Green's function calculations, we study the charge transport properties of the CNB/metal electrode interfaces, and show that the C60 bonding to the CNT cap or open end induces resonant transmissions near the Fermi level. It is also found that the good electronic linkage in the CNT cap-C60 cycloaddition bonds results in the absence of quantum interference patterns, which contrasts with the case of the CNB formed on an open-ended CNT that shows a Fano resonance profile.
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Affiliation(s)
- Ji Il Choi
- Graduate School of Energy, Environment, Water, and Sustainability, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea.
| | - Hyo Seok Kim
- Graduate School of Energy, Environment, Water, and Sustainability, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea.
| | - Han Seul Kim
- Graduate School of Energy, Environment, Water, and Sustainability, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea.
| | - Ga In Lee
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea
| | - Jeung Ku Kang
- Graduate School of Energy, Environment, Water, and Sustainability, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea. and Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea
| | - Yong-Hoon Kim
- Graduate School of Energy, Environment, Water, and Sustainability, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea.
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Brunello GF, Lee JH, Lee SG, Choi JI, Harvey D, Jang SS. Interactions of Pt nanoparticles with molecular components in polymer electrolyte membrane fuel cells: multi-scale modeling approach. RSC Adv 2016. [DOI: 10.1039/c6ra09274h] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Three phase model consists of Pt nanoparticles, Nafion, and graphite with oxygen, water, and hydronium.
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Affiliation(s)
- Giuseppe F. Brunello
- Computational NanoBio Technology Laboratory
- School of Materials Science and Engineering
- Georgia Institute of Technology
- Atlanta
- USA
| | - Ji Hye Lee
- Department of Organic Material Science and Engineering
- Pusan National University
- Busan 46241
- Republic of Korea
| | - Seung Geol Lee
- Department of Organic Material Science and Engineering
- Pusan National University
- Busan 46241
- Republic of Korea
| | - Ji Il Choi
- Computational NanoBio Technology Laboratory
- School of Materials Science and Engineering
- Georgia Institute of Technology
- Atlanta
- USA
| | | | - Seung Soon Jang
- Computational NanoBio Technology Laboratory
- School of Materials Science and Engineering
- Georgia Institute of Technology
- Atlanta
- USA
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Choi JI, Lee HJ, Shin YJ, Lim HW, Lee HN. Rapid enlargement of endometrial stromal sarcoma after uterine fibroid embolization for presumed adenomyosis: a case report and literature review. EUR J GYNAECOL ONCOL 2016; 37:876-881. [PMID: 29943942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Uterine sarcomas have rarely been diagnosed after uterine artery embolization. It remains unclear whether the diagnostic work-up is required prior to such embolization to prevent a missed diagnosis of sarcomas and a delay in providing definitive treatment. Because of the rarity and heterogeneity of endometrial stromal neoplasms, little is known about their epidemiology, pathogenesis, and molecular pathology. The authors report a case of low-grade endometrial stromal sarcoma (ESS) diagnosed after uterine fibroid embolization. Although they performed laparoscopic biopsy of the rapidly growing uterine mass, they could not detect the ESS. Although rare, ESS should be considered in the differential diagnosis of uterine fibroid enlargement. It is essential to assess the risk of malignancy by taking into account the patient's clinical symptoms, results of the physical exam, and imaging findings prior to uterine artery embolization. Pathologic diagnosis should include an adequate biopsy sample and the use of molecular genetic testing.
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Chun BJ, Lee SG, Choi JI, Jang SS. Adsorption of carboxylate on calcium carbonate (10 1¯ 4) surface: Molecular simulation approach. Colloids Surf A Physicochem Eng Asp 2015. [DOI: 10.1016/j.colsurfa.2015.03.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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28
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Chun BJ, Choi JI, Jang SS. Molecular dynamics simulation study of sodium dodecyl sulfate micelle: Water penetration and sodium dodecyl sulfate dissociation. Colloids Surf A Physicochem Eng Asp 2015. [DOI: 10.1016/j.colsurfa.2015.03.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Choi JI, Snow SD, Kim JH, Jang SS. Interaction of C₆₀ with water: first-principles modeling and environmental implications. Environ Sci Technol 2015; 49:1529-1536. [PMID: 25602529 DOI: 10.1021/es504614u] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The nature of fullerene-water interactions has been the subject of much research and debate. Specifically, the presence of a stabilizing, negative surface potential on colloidal aggregates of C60 in water is unexpected, given the neutral nature of pure carbon, and is not well understood. Previous simulation efforts have focused on the C60-water interaction using molecular dynamics simulations that lacked the ability to account for charge transfer and distribution interactions. In this study, first-principles density functional theory was used to analyze the fundamental electronic interactions to elucidate the polarization and charge transfer between water and C60. Simulations show that charge is inductively transferred to the C60 from water molecules, with subsequent polarization of the C60 molecule. In a case with two neighboring C60 molecules, the charge polarization induces a charge onto the second C60. Simulation suggests that this charge transfer and polarization may contribute at least partly to the observed negative surface potential of fullerene aggregates and, combined with hydrogen bonding network formation around C60, provides a fundamental driving force for aggregate formation in water.
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Affiliation(s)
- Ji Il Choi
- Computational NanoBio Technology Laboratory, School of Materials Science and Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332-0245, United States
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30
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Abstract
The adsorption mechanism of Li onto the graphene–C60 nanobud structure.
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Affiliation(s)
- Wonsang Koh
- School of Physics
- Georgia Institute of Technology
- Atlanta
- USA
| | - Ji Hye Lee
- Department of Organic Material Science and Engineering
- Pusan National University
- Busan 609-735
- Republic of Korea
| | - Seung Geol Lee
- Department of Organic Material Science and Engineering
- Pusan National University
- Busan 609-735
- Republic of Korea
| | - Ji Il Choi
- Graduate School of EEWS
- Korea Advanced Institute of Science and Technology
- Daejeon 305-701
- Republic of Korea
| | - Seung Soon Jang
- School of Materials Science and Engineering
- Georgia Institute of Technology
- Atlanta
- USA
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31
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Lee DK, Park JH, Choi JI, Lee Y, Kim SJ, Lee GH, Kim YH, Kang JK. A facile synthesis of multi metal-doped rectangular ZnO nanocrystals using a nanocrystalline metal-organic framework template. Nanoscale 2014; 6:10995-11001. [PMID: 25123292 DOI: 10.1039/c4nr03424d] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A multi metal (M: Fe, Co, and Ni)-doped rectangular ZnO nanocrystal (r-ZnO:M) was synthesised using nanocrystalline metal-organic framework-5 (n-MOF-5). After calcination in air, M-inserted n-MOF-5 led to r-ZnO:M of the wurtzite crystal structure with a small amount (<1%) of spinel ZnM2O4 phase. The inserted metal atoms of r-ZnO:M, replacing the Zn atoms of the wurtzite ZnO structure, were well-dispersed throughout the nanocrystal. Density functional theory calculations not only confirm the structural stability of wurtzite r-ZnO:M and negligible contribution of spinel ZnM2O4 but also elucidate the experimentally observed increase of visible light absorbance and appearance of ferromagnetism upon metal atom doping.
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Affiliation(s)
- Dong Ki Lee
- Department of Materials Science & Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea
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Jin JY, Choi EY, Park HR, Choi JI, Choi IS, Kim SJ. Isorhamnetin inhibits Prevotella intermedia lipopolysaccharide-induced production of interleukin-6 in murine macrophages via anti-inflammatory heme oxygenase-1 induction and inhibition of nuclear factor-κB and signal transducer and activator of transcription 1 activation. J Periodontal Res 2013; 48:687-95. [PMID: 23441850 DOI: 10.1111/jre.12054] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/03/2013] [Indexed: 11/28/2022]
Abstract
BACKGROUND AND OBJECTIVE Interleukin-6 (IL-6) is a key proinflammatory cytokine that has been considered to be important in the pathogenesis of periodontal disease. Therefore, host-modulatory agents directed at inhibiting IL-6 appear to be beneficial in terms of attenuating periodontal disease progression and potentially improving disease susceptibility. In the current study, we investigated the effect of the flavonoid isorhamnetin on the production of IL-6 in murine macrophages stimulated with lipopolysaccharide (LPS) from Prevotella intermedia, a pathogen implicated in inflammatory periodontal disease, and its mechanisms of action. MATERIAL AND METHODS Lipopolysaccharide from P. intermedia ATCC 25611 was isolated using the standard hot phenol-water method. Culture supernatants were collected and assayed for IL-6. We used real-time PCR to quantify IL-6 and heme oxygenase-1 (HO-1) mRNA expression. The expression of HO-1 protein and the levels of signaling proteins were monitored using immunoblot analyses. The DNA-binding activity of nuclear factor-κB (NF-κB) was analyzed using ELISA-based assay kits. RESULTS Isorhamnetin significantly down-regulated P. intermedia LPS-induced production of IL-6 as well as its mRNA expression in RAW264.7 cells. Isorhamnetin up-regulated the expression of HO-1 at both gene transcription and translation levels in cells stimulated with P. intermedia LPS. In addition, inhibition of HO-1 activity by tin protoporphyrin IX blocked the inhibitory effect of isorhamnetin on IL-6 production. Isorhamnetin failed to prevent LPS from activating either c-Jun N-terminal kinase or p38 pathways. Isorhamnetin did not inhibit NF-κB transcriptional activity at the level of inhibitory κB-α degradation. Isorhamnetin suppressed NF-κB signaling through inhibition of nuclear translocation and DNA binding activity of NF-κB p50 subunit and attenuated signal transducer and activator of transcription 1 signaling. CONCLUSION Although further research is required to clarify the detailed mechanism of action, we propose that isorhamnetin may contribute to blockade of the host-destructive processes mediated by IL-6 and could be a highly efficient modulator of the host response in the treatment of inflammatory periodontal disease. Further research in animal models of periodontitis is required to better evaluate, the potential of isorhamnetin as a novel agent for treating periodontal disease.
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Affiliation(s)
- J Y Jin
- Department of Biological Science, College of Medical and Life Sciences, Silla University, Busan, Korea
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Ford ENJ, Minusa ML, Liu T, Choi JI, Jang SS, Kumar S. Influence of SWNTs on the Preferential Alignment of Molecular Moieties in PVA Fibers. MACROMOL CHEM PHYS 2012. [DOI: 10.1002/macp.201100534] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Jeong S, Lee HG, Kim WM, Jeong CW, Lee SH, Yoon MH, Choi JI. Increase of paradoxical excitement response during propofol-induced sedation in hazardous and harmful alcohol drinkers. Br J Anaesth 2011; 107:930-3. [PMID: 21903640 DOI: 10.1093/bja/aer275] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Paradoxical excitement response during sedation consists of loss of affective control and abnormal movements. Chronic alcohol abuse has been proposed as a predisposing factor despite lack of supporting evidence. Because alcohol and propofol have a common site of action, we postulated that paradoxical excitement responses during propofol-induced sedation occur more frequently in hazardous and harmful alcohol drinkers than in social or non-drinkers. METHODS One hundred and ninety patients undergoing orthopaedic knee joint surgery were enrolled in this prospective and observational study. Subjects were divided into Group HD (hazardous and harmful drinkers) or Group NHD (no hazardous drinkers) according to the alcohol use disorder identification test (AUDIT). In study 1, propofol infusion was adjusted to achieve the bispectral index at 70-80 using target-controlled infusion. In study 2, the target concentration of propofol was fixed at 0.8 (study 2/Low) or 1.4 μg ml(-1) (study 2/High). Paradoxical excitement responses were categorized by intensity into mild, moderate, or severe. RESULTS The overall incidence of paradoxical excitement response was higher in Group HD than in Group NHD in study 1 (71.4% vs 43.8%; P=0.022) and study 2/High (70.0% vs 34.5%; P=0.006) but not in study 2/Low. The incidence of moderate-to-severe response was significantly higher in Group HD of study 1 (28.6% vs 3.1%; P=0.0005) and study 2/High (23.3% vs 3.4%; P=0.029) with no difference in study 2/Low. Severe excitement response occurred only in Group HD of study 1 and study 2/High. CONCLUSIONS Paradoxical excitement occurred more frequently and severely in hazardous and harmful alcohol drinkers than in social drinkers during propofol-induced moderate-to-deep sedation, but not during light sedation.
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Affiliation(s)
- S Jeong
- Department of Anesthesiology and Pain Medicine, Chonnam National University Medical School and Hospital, 671 Jebongro Dong-gu, Gwangju 501-757, Republic of Korea
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35
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Koh W, Choi JI, Donaher K, Lee SG, Jang SS. Mechanism of Li adsorption on carbon nanotube-fullerene hybrid system: a first-principles study. ACS Appl Mater Interfaces 2011; 3:1186-1194. [PMID: 21443264 DOI: 10.1021/am200018w] [Citation(s) in RCA: 10] [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: 05/30/2023]
Abstract
The lithium (Li) adsorption mechanism on the metallic (5,5) single wall carbon nanotube (SWCNT)-fullerene (C(60)) hybrid material system is investigated using first-principles method. It is found that the Li adsorption energy (-2.649 eV) on the CNT-C(60) hybrid system is lower than that on the peapod system (-1.837 eV) and the bare CNT (-1.720 eV), indicating that the Li adsorption on the CNT-C(60) hybrid system is more stable than on the peapod or bare CNT system. This is due to the C(60) of high electron affinity and the charge redistribution after mixing CNT with C(60). In order to estimate how efficiently Li can utilize the vast surface area of the hybrid system for increasing energy density, the Li adsorption energy is calculated as a function of the adsorption positions around the CNT-C(60) hybrid system. It turns out that Li preferably occupies the mid-space between C(60) and CNT and then wraps up the C(60) side and subsequently the CNT side. It is also found that the electronic properties of the CNT-C(60) system, such as band structure, molecular orbital, and charge distribution, are influenced by the Li adsorption as a function of the number of Li atoms. From the results, it is expected that the CNT-C(60) hybrid system has enhanced the charge transport properties in addition to the Li adsorption, compared to both CNT and C(60).
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Affiliation(s)
- Wonsang Koh
- School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive NW, Atlanta, Georgia 30332-0245, USA
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Pak HN, Kim JS, Shin SY, Lee HS, Choi JI, Lim HE, Hwang C, Kim YH. Is Empirical Four Pulmonary Vein Isolation Necessary for Focally Triggered Paroxysmal Atrial Fibrillation? Comparison of Selective Pulmonary Vein Isolation Versus Empirical Four Pulmonary Vein Isolation. J Atr Fibrillation 2008; 1:99. [PMID: 28496581 PMCID: PMC4955819 DOI: 10.4022/jafib.99] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2008] [Revised: 07/11/2008] [Accepted: 07/14/2008] [Indexed: 06/07/2023]
Affiliation(s)
- H N Pak
- Andrea Corrado and Antonio Raviele "Dell'Angelo" Hospital of Mestre, Venezia, Italy
| | - J S Kim
- Andrea Corrado and Antonio Raviele "Dell'Angelo" Hospital of Mestre, Venezia, Italy
| | - S Y Shin
- Andrea Corrado and Antonio Raviele "Dell'Angelo" Hospital of Mestre, Venezia, Italy
| | - H S Lee
- Andrea Corrado and Antonio Raviele "Dell'Angelo" Hospital of Mestre, Venezia, Italy
| | - J I Choi
- Andrea Corrado and Antonio Raviele "Dell'Angelo" Hospital of Mestre, Venezia, Italy
| | - H E Lim
- Andrea Corrado and Antonio Raviele "Dell'Angelo" Hospital of Mestre, Venezia, Italy
| | - C Hwang
- Andrea Corrado and Antonio Raviele "Dell'Angelo" Hospital of Mestre, Venezia, Italy
| | - Y H Kim
- Andrea Corrado and Antonio Raviele "Dell'Angelo" Hospital of Mestre, Venezia, Italy
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Cha BK, Choi JI, Jost-Brinkmann PG, Jeong YM. Applications of three-dimensionally scanned models in orthodontics. Int J Comput Dent 2007; 10:41-52. [PMID: 17455767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The purpose of this study was to investigate clinical applications of the three-dimensional reverse engineering technologies for the analysis of orthodontic models. The measuring accuracy and the process of the 3D model scanning technique were evaluated with respect to linear, surface and volumetric parameters. Orthodontically induced dentoalveolar changes, which have been traditionally evaluated by cephalometric analysis, were assessed by the registration function of Rapidform 2002, a 3D-reverse modeling software in scanned maxillary casts. Three-dimensional digital models are valuable alternatives to conventional casts for model analysis and also yield information which could previously be gathered only by cephalometric superimposition.
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Affiliation(s)
- B K Cha
- Department of Orthodontics, College of Dentistry, Kangnung National University, Gangneung, South Korea.
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Yoon MH, Choi JI, Kim SJ, Kim CM, Bae HB, Chung ST. Synergistic antinociception between zaprinast and morphine in the spinal cord of rats on the formalin test. Eur J Anaesthesiol 2006; 23:65-70. [PMID: 16390569 DOI: 10.1017/s0265021505001791] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/27/2005] [Indexed: 11/06/2022]
Abstract
BACKGROUND AND OBJECTIVE The cyclic guanosine monophosphate level, which causes an antinociception, is increased in cells as a direct result of phosphodiesterase inhibition. This study used a nociceptive test to examine the nature of the pharmacological interaction between intrathecal zaprinast, a phosphodiesterase inhibitor, and morphine. METHODS Catheters were inserted into the intrathecal space through an incision in the atlantooccipital membrane of male Sprague-Dawley rats. As a nociceptive model, 50 microL of a 5% formalin solution was injected into the hind paw. After observing the effect of zaprinast (37, 111, 369 nmol) and morphine (1, 4, 10, 40 nmol) alone, the interactions of their combination were examined by an isobolographic analysis. RESULTS Intrathecal zaprinast (P < 0.05) and morphine (P < 0.05) dose-dependently suppressed the flinching observed during phase 1 and phase 2 in the formalin test. The ED50 values (95% confidence intervals) of zaprinast and morphine in phase 1 were 161.9 (87.9-298.3) and 11.6 nmol (4.8-27.9 nmol), respectively. The phase 2 ED50 values (95% confidence intervals) of zaprinast and morphine were 229.9 (142.5-370.9) and 3.9 nmol (1.9-7.6 nmol), respectively. Isobolographic analysis revealed a synergistic interaction after intrathecal delivery a zaprinast-morphine mixture in both phases. The ED50 values of (95% confidence intervals) zaprinast in the combination of zaprinast with morphine in phase 1 and phase 2 were 14.2 (4.9-40.6) and 10.4 nmol (3-35.9 nmol), respectively. CONCLUSIONS Intrathecal zaprinast and morphine are effective against acute pain and facilitated pain state. Zaprinast interacts synergistically with morphine.
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Affiliation(s)
- M H Yoon
- Chonnam National University, Medical School, Department of Anesthesiology and Pain Medicine, Gwangju, Korea
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Abstract
BACKGROUND Intrathecal cholinesterase inhibitors have been shown to have an antinociceptive effect which is mediated through the spinal cholinergic receptors, mainly muscarinic receptor. Spinal nicotinic receptor also has been involved in the control of nociception. Authors characterized the respective role of muscarinic or nicotinic receptor for the antinociception of cholinesterase inhibitors and further determined the antinociceptive potency of them. METHODS Rats were prepared with intrathecal catheters. Formalin-induced flinching response was regarded as a nociceptive behavior. RESULTS Intrathecal neostigmine, physostigmine and edrophonium produced a dose-dependent suppression of flinching in both phases. Atropine and the M1 selective antagonist attenuated the effect of them, while the M2 selective antagonist did not affect. M3, M4 selective, and nicotinic receptor antagonists reversed the antinociception induced by edrophonium, but by neither neostigmine nor physostigmine. The ordering of potency was neostigmine > physostigmine > > edrophonium. CONCLUSION These data indicate that the nicotinic receptor may be involved, at least in part, in the antinociceptive action of cholinesterase inhibitor at the spinal level, and M1 receptor subtype may be a common pharmacologic site of action. Moreover, neostigmine is more potent than physostigmine and edrophonium.
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Affiliation(s)
- M H Yoon
- Department of Anesthesiology and Pain Medicine, Chonnam National University, Medical School, Gwangju, Korea.
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Abstract
Polyhydroxyalkanoates (PHAs) can be produced from renewable sources and are biodegradable with similar material properties and processibility to conventional plastic materials. With recent advances in our understanding of the biochemistry and genetics of PHA biosynthesis and cloning of the PHA biosynthesis genes from a number of different bacteria, many different recombinant bacteria have been developed to improve PHA production for commercial applications. For enhancing PHA synthetic capacity, homologous or heterologous expression of the PHA biosynthetic enzymes has been attempted. Several genes that allow utilization of various substrates were transformed into PHA producers, or non-PHA producers utilizing inexpensive carbon substrate were transformed with the PHA biosynthesis genes. Novel PHAs have been synthesized by introducing a new PHA biosynthesis pathway or a new PHA synthase gene. In this article, recent advances in the production of PHA by recombinant bacteria are described.
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Affiliation(s)
- S Y Lee
- Department of Chemical Engineering and BioProcess Engineering Research Center, Korea Advanced Institute of Science and Technology, 373-1 Kusong-dong, Yusong-gu, Taejon 305-701, Korea.
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Park SH, Kim TK, Lee KH, Kim AY, Choi JI, Han JK, Choi BI. Quantitative comparison of tumor vascularity of hepatocellular carcinoma after intravenous contrast agent: conventional versus harmonic power Doppler US. Abdom Imaging 2001; 26:178-83. [PMID: 11178696 DOI: 10.1007/s002610000129] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND The purpose of this study was to make a quantitative comparison between conventional and harmonic power Doppler (PD) ultrasound (US) in depicting vascularity of hepatocellular carcinoma (HCC). METHODS Ten nodular HCCs in 10 patients were prospectively examined using a 2-4-MHz convex transducer and a standardized examination protocol. Serial US images were obtained before and 20, 30, 40, 50, 60, 90, 120, 150, 180, 240, and 300 s after intravenous injection of 2 g of contrast agent using conventional and harmonic PD US. The percentage of area with Doppler signal within each HCC nodule (%PDA) was calculated in each image with a PC-based image analysis program, and the results with both US techniques were compared. RESULTS In the majority of cases, %PDA was greater on conventional PD US than on harmonic PD US. Mean %PDA of 10 HCCs was significantly higher on conventional PD US than on harmonic PD US except at 20 s after injection. The highest values of mean %PDA were 34.9% in conventional PD US and 19.5% in harmonic PD US at 60 s after injection. CONCLUSION Area with PD signals within the HCC is smaller and the duration of effective enhancement is shorter in harmonic PD US than in conventional PD US.
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Affiliation(s)
- S H Park
- Department of Radiology and the Institute of Radiation Medicine, Seoul National University College of Medicine, 28, Yongon-dong, Chongno-gu, Seoul 110-744, Korea
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Lee JB, Lee MH, Kim SJ, Choi JI. Combined periodontal-prosthodontic treatment of early-onset periodontitis--an alternative to implant therapy. INT J PERIODONT REST 2000; 20:604-11. [PMID: 11203597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
A variety of treatment systems should be available for patients whose dentitions are seriously compromised so that they may select customized treatment modalities that satisfactorily restore occlusal function, consider systemic conditions, and lessen the surgical and financial burdens. These requirements become more demanding when clinicians are faced with advanced cases of rapidly progressive periodontitis. Therefore, it is critical to establish sophisticated multidisciplinary treatment modalities for the successful management of these compromised patients. Obviously, because of various limitations, implant therapy cannot be the only solution. This article reports on the successful long-term management of seriously compromised early-onset periodontitis by a combined periodontal-prosthetic treatment as an alternative to implant therapy.
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Affiliation(s)
- J B Lee
- Department of Dentistry, School of Medicine, Ajou University, Suwon, Korea
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Choi JI, Borrello MA, Smith ES, Zauderer M. Polarization of Porphyromonas gingivalis-specific helper T-cell subsets by prior immunization with Fusobacterium nucleatum. Oral Microbiol Immunol 2000; 15:181-7. [PMID: 11154401 DOI: 10.1034/j.1399-302x.2000.150306.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Antigen-specific T-cell clones were obtained from mice immunized with Fusobacterium nucleatum ATCC 10953 and/or Porphyromonas gingivalis 381. 10 BALB/c mice per group were immunized with F. nucleatum followed by P. gingivalis, or with P. gingivalis alone by intraperitoneal injection of viable microorganisms. Spleen T cells were isolated and stimulated in vitro with viable P. gingivalis cells to establish P. gingivalis-specific T-cell clones. T-cell phenotypes and cytokine profiles were determined along with T-cell responsiveness to F. nucleatum or P. gingivalis. Serum immunoglobulin G antibody titers to F. nucleatum or P. gingivalis were also determined by enzyme-linked immunosorbent assay. All the T-cell clones derived from mice immunized with F. nucleatum followed by P. gingivalis demonstrated Th2 subsets, while those from mice immunized with P. gingivalis alone demonstrated Th1 subsets based on the flow cytometric analysis and cytokine profiles. All T-cell clones from both groups were cross-reactive to both P. gingivalis and F. nucleatum antigens. Phenotypes of T-cell clones were all positive for CD4. Mean post-immune serum IgG antibody levels to F. nucleatum or P. gingivalis were significantly higher than the pre-immune levels (P < 0.05, P < 0.01, respectively). There were no significant differences in the antibody titers between the two groups. It was concluded that P. gingivalis-specific T cells initially primed by cross-reactive F. nucleatum antigens were polarized to Th2 subset, while T cells stimulated with P. gingivalis alone maintained the profile of Th1 subset.
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Affiliation(s)
- J I Choi
- Cancer Center, Division of Immunology, School of Medicine and Dentistry, University of Rochester, New York, USA
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Abstract
Fermentation strategies for production of high concentrations of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(3HB-co-3HV)] with different 3-hydroxyvalerate (3HV) fractions by recombinant Escherichia coli harboring the Alcaligenes latus polyhydroxyalkanoate biosynthesis genes were developed. Fed-batch cultures of recombinant E. coli with the pH-stat feeding strategy facilitated production of high concentrations and high contents of P(3HB-co-3HV) in a chemically defined medium. When a feeding solution was added in order to increase the glucose and propionic acid concentrations to 20 g/liter and 20 mM, respectively, after each feeding, a cell dry weight of 120.3 g/liter and a relatively low P(3HB-co-3HV) content, 42.5 wt%, were obtained. Accumulation of a high residual concentration of propionic acid in the medium was the reason for the low P(3HB-co-3HV) content. An acetic acid induction strategy was used to stimulate the uptake and utilization of propionic acid. When a fed-batch culture and this strategy were used, we obtained a cell concentration, a P(3HB-co-3HV) concentration, a P(3HB-co-3HV) content, and a 3HV fraction of 141.9 g/liter, 88.1 g/liter, 62.1 wt%, and 15.3 mol%, respectively. When an improved nutrient feeding strategy, acetic acid induction, and oleic acid supplementation were used, we obtained a cell concentration, a P(3HB-co-3HV) concentration, a P(3HB-co-3HV) content, and a 3HV fraction of 203.1 g/liter, 158.8 g/liter, 78.2 wt%, and 10.6 mol%, respectively; this resulted in a high level of productivity, 2.88 g of P(3HB-co-3HV)/liter-h.
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Affiliation(s)
- J I Choi
- Department of Chemical Engineering and BioProcess Engineering Research Center, Korea Advanced Institute of Science and Technology, 373-1, Kusong-dong, Yusong-gu, Taejon 305-701, Korea
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Choi JI, Lee SY, Han K. Cloning of the Alcaligenes latus polyhydroxyalkanoate biosynthesis genes and use of these genes for enhanced production of Poly(3-hydroxybutyrate) in Escherichia coli. Appl Environ Microbiol 1998; 64:4897-903. [PMID: 9835580 PMCID: PMC90940 DOI: 10.1128/aem.64.12.4897-4903.1998] [Citation(s) in RCA: 97] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Polyhydroxyalkanoates (PHAs) are microbial polyesters that can be used as completely biodegradable polymers, but the high production cost prevents their use in a wide range of applications. Recombinant Escherichia coli strains harboring the Ralstonia eutropha PHA biosynthesis genes have been reported to have several advantages as PHA producers compared with wild-type PHA-producing bacteria. However, the PHA productivity (amount of PHA produced per unit volume per unit time) obtained with these recombinant E. coli strains has been lower than that obtained with the wild-type bacterium Alcaligenes latus. To endow the potentially superior PHA biosynthetic machinery to E. coli, we cloned the PHA biosynthesis genes from A. latus. The three PHA biosynthesis genes formed an operon with the order PHA synthase, beta-ketothiolase, and reductase genes and were constitutively expressed from the natural promoter in E. coli. Recombinant E. coli strains harboring the A. latus PHA biosynthesis genes accumulated poly(3-hydroxybutyrate) (PHB), a model PHA product, more efficiently than those harboring the R. eutropha genes. With a pH-stat fed-batch culture of recombinant E. coli harboring a stable plasmid containing the A. latus PHA biosynthesis genes, final cell and PHB concentrations of 194.1 and 141.6 g/liter, respectively, were obtained, resulting in a high productivity of 4.63 g of PHB/liter/h. This improvement should allow recombinant E. coli to be used for the production of PHB with a high level of economic competitiveness.
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Affiliation(s)
- J I Choi
- Department of Chemical Engineering, Korea Advanced Institute of Science and Technology, 373-1 Kusong-dong, Yusong-gu, Taejon 305-701, Korea
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Choi JI, Schifferle RE, Yoshimura F, Kim BW. Capsular polysaccharide-fimbrial protein conjugate vaccine protects against Porphyromonas gingivalis infection in SCID mice reconstituted with human peripheral blood lymphocytes. Infect Immun 1998; 66:391-3. [PMID: 9423888 PMCID: PMC107916 DOI: 10.1128/iai.66.1.391-393.1998] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The effect of immunization with either a Porphyromonas gingivalis fimbrial protein, a capsular polysaccharide, or a capsular polysaccharide-fimbrial protein conjugate vaccine were compared in hu-PBL-SCID mice. A significantly higher human immunoglobulin G antibody response and the highest degree of in vivo protection against bacterial challenge was observed in the group immunized with the conjugate vaccine. It was concluded that capsular polysaccharide-fimbrial protein conjugate from P. gingivalis could potentially be developed as a vaccine against periodontal infection by P. gingivalis.
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Affiliation(s)
- J I Choi
- Department of Pediatrics, University of Rochester, New York 14642, USA.
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Choi JI, Ha MH, Kim JH, Kim SJ. Immunoglobulin allotypes and immunoglobulin G subclass responses to Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis in early-onset periodontitis. Infect Immun 1996; 64:4226-30. [PMID: 8926092 PMCID: PMC174360 DOI: 10.1128/iai.64.10.4226-4230.1996] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The present study was performed to estimate the observed frequencies of the immunoglobulin heavy-chain (Gm) and light-chain (Km) allotypes among patients with early-onset periodontitis (EOP) and their effect on the IgG2 subclass responses against Actinobacillus actinomycetemcomitans Y4 and Porphyromonas gingivalis 381, respectively. Sixty-nine EOP patients, including 11 with localized juvenile periodontitis (LJP), 19 who had LJP, 15 with LJP-rapidly progressing periodontitis (RPP), and 24 with RPP, were examined for the Gm and Km allotypes by a hemagglutination inhibition test. Levels of immunoglobulin G2 (IgG2) antibodies against the two organisms were determined by enzyme-linked immunosorbent assay. Fifty race- and age-matched, periodontally healthy subjects were also included as a control group. The observed frequencies of the Gm haplotype afnb and Km(1) were significantly higher in the RPP and LJP groups, respectively. The G2m(n)+ group of those with RPP and the Km(1)+ group of those with LJP had significantly higher levels of IgG2 antibodies to A. actinomycetemcomitans and P. gingivalis, respectively. The results indicate that linkage disequilibrium of the G2m(n) locus in RPP patients or the Km(1) locus in LJP patients may be associated with high IgG2 antibody responses to the respective bacteria. It was reasoned that the IgG2 antibody responses are associated with the immunoglobulin allotypes. The function of IgG2 antibodies in their reaction to different bacterial antigens may be interpreted as either protective or nonprotective in the two different types of EOP (i.e., LJP and RPP).
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Affiliation(s)
- J I Choi
- Research Center for Periodontal Disease and Department of Periodontology, School of Dentistry, Pusan National University, Korea
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Kim SJ, Kato T, Naito Y, Hirai K, Choi JI, Takazoe I, Okuda K. B-cell mitogenicity and IL-1 beta production of lipopolysaccharides from various Capnocytophaga strains. Bull Tokyo Dent Coll 1994; 35:79-83. [PMID: 7987967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
To evaluate the etiological roles of Capnocytophaga species in the pathogenesis of periodontal disease, we examined the immunological activities of lipopolysaccharides (LPSs) from various Capnocytophaga strains. All LPSs from various Capnocytophaga species were mitogenic for BALB/c mouse spleen cells, although the responses were lower than those to reference LPSs from Escherichia coli or Salmonella typhimurium. LPSs of C. sputigena strains had polyclonal B cell activation and adjuvant activity and were comparable to reference LPSs. All LPSs from Capnocytophaga strains activated the interleukin-1 beta production from human peripheral monocytes, although the inducing activities of Capnocytophaga LPSs were lower than those of reference LPSs. It appears that LPSs from various Capnocytophaga strains activate certain immunological responses from lymphocytes and monocytes which may be important in the development and pathogenesis of periodontal disease.
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Affiliation(s)
- S J Kim
- Department of Periodontology, College of Dentistry, Pusan National University, Korea
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Kim SJ, Kato T, Naito Y, Hirai K, Choi JI, Takazoe I, Okuda K. Lipopolysaccharides from various Capnocytophaga strains possess potent Limulus amoebocyte lysate clotting activity. Bull Tokyo Dent Coll 1994; 35:17-21. [PMID: 7923506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Lipopolysaccharides (LPSs) were extracted by the hot phenol-water method from three ATCC strains (C. sputigena ATCC 33612, C. ochracea ATCC 33596, and C. gingivalis ATCC 33624) and three clinical isolates (C. sputigena TE-1, C. ochracea ONO-26, and C. gingivalis M-12). Endospecy was used to determine the Limulus amoebocyte lysate clotting activities. The activities of LPSs from Capnocytophaga strains were stronger than those of Escherichia coli, with the exception of the LPS from C. gingivalis M-12. Except for the LPS from C. sputigena TE-1, the SDS-PAGE analyses of these preparations showed slow-migrating and repeating ladder bands similar to the LPSs of E. coli and Salmonella typhimurium (wild type) and included both the core-lipid A region and various lengths of O-antigen. The LPS from C. sputigena TE-1 possessed fast-migrating bands and did not have an O-side chain.
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Affiliation(s)
- S J Kim
- Department of Periodontology, College of Dentistry, Pusan National University, Korea
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Reinhardt RA, Masada MP, Kaldahl WB, DuBois LM, Kornman KS, Choi JI, Kalkwarf KL, Allison AC. Gingival fluid IL-1 and IL-6 levels in refractory periodontitis. J Clin Periodontol 1993; 20:225-31. [PMID: 8383708 DOI: 10.1111/j.1600-051x.1993.tb00348.x] [Citation(s) in RCA: 136] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Selected gingival bacteria and cytokine profiles associated with patients who did not respond to conventional periodontal therapy (refractory) were evaluated. 10 subjects with a high incidence of post-active treatment clinical attachment loss (> 2% sites/year lost > or = 3 mm) were compared to 10 age-, race-, and supragingival plaque-matched patients with low post-treatment clinical attachment loss (< 0.5% sites/year) relative to the following parameters at 2 sites/patient with the deepest probing depths: (1) presence of 3 selected periodontal pathogens (Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Eikenella corrodens) in subgingival plaque as determined by selective culturing, and (2) gingival crevicular fluid (GCF) levels of 3 cytokines associated with bone resorption (IL-1 alpha, IL-1 beta, IL-6) as determined by two-site ELISA. Results indicated no significant differences in any clinical measurement (except incidence of clinical attachment loss), in the presence of any bacterial pathogen, or in GCF cytokine levels between refractory subject sites versus stable subject sites. However, when sites producing the greatest total GCF cytokine/patient were compared, sites from refractory patient produced significantly more IL-6 (30.1 +/- 4.0 versus 15.4 +/- 2.8 nM, p < 0.01). The subgingival presence of each of the 3 bacterial pathogens was associated with elevated GCF IL-1 concentrations. These data suggest that gingival IL-1 and IL-6 production is different in response to local and systemic factors associated with periodontitis, and that IL-6 may play a role in the identification and mechanisms of refractory periodontitis.
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Affiliation(s)
- R A Reinhardt
- Department of Periodontics, University of Nebraska Medical Center, College of Dentistry, Lincoln 68583-0740
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