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30 results on '"Jeon, Jaewan"'

9. PdIn-Based Pseudo-Binary Alloy as a Catalyst for NOx Removal under Lean Conditions

Author

Jeon, Jaewan, Ham, Hyungwon, Xing, Feilong, Nakaya, Yuki, Shimizu, Ken-ichi, and Furukawa, Shinya

Subjects
PdIn, NOx removal, pseudobinary alloy, lean condition, intermetallic compound
Abstract

Developing a noble-metal-based catalyst that works effectively for NOx removal in the presence of excess O-2 is still a big challenge in catalytic chemistry for exhaust gas purification. To overcome this challenge, in this study, we designed and prepared a nanoparticulate (Pd1-xPtx)In pseudobinary alloy using Al2O3 and CeO2 supports, where a portion of Pd was replaced with Pt to improve the oxidation tolerance of In during NOx reduction under lean conditions. Multiple characterization techniques were used to confirm the formation of the desired pseudobinary alloy phase. The prepared Pd-Pt-In/CeO2 catalyst exhibited high NO conversion to N-2 in NO-CO-O-2 reaction with a wide range of oxygen concentrations including lean conditions (80%-100%, 0.75

Published
2020

14. A Cu–Pd single-atom alloy catalyst for highly efficient NO reduction† †Electronic supplementary information (ESI) available: Details of characterization, kinetic analysis, and DFT calculations. See DOI: 10.1039/c9sc03172c

Author

Xing, Feilong, Jeon, Jaewan, Toyao, Takashi, Shimizu, Ken-ichi, and Furukawa, Shinya

Subjects
Chemistry
Abstract

Highly active and selective NO reduction was achieved at low temperatures using a minimum amount of noble metal Pd., A series of Cu–Pd alloy nanoparticles supported on Al2O3 were prepared and tested as catalysts for deNOx reactions. XRD, HAADF-STEM, XAFS, and FT-IR analyses revealed that a single-atom alloy structure was formed when the Cu/Pd ratio was 5, where Pd atoms were well isolated by Cu atoms. Compared with Pd/Al2O3, Cu5Pd/Al2O3 exhibited outstanding catalytic activity and N2 selectivity in the reduction of NO by CO: for the first time, the complete conversion of NO to N2 was achieved even at 175 °C, with long-term stability for at least 30 h. High catalytic performance was also obtained in the presence of O2 and C3H6 (model exhaust gas), where a 90% decrease in Pd use was achieved with minimum evolution of N2O. Kinetic and DFT studies demonstrated that N–O bond breaking of the (NO)2 dimer was the rate-determining step and was kinetically promoted by the isolated Pd.

Published
2019

15. Additional file 9 of Downregulated CLIP3 induces radioresistance by enhancing stemness and glycolytic flux in glioblastoma

Author

Kang, Hyunkoo, Lee, Sungmin, Kim, Kyeongmin, Jeon, Jaewan, Kang, Seok-Gu, Youn, HyeSook, Kim, Hae Yu, and Youn, BuHyun

Abstract

Additional file 9: Figure S1. Spy1 and CLIP3 expression in gliomas correlates with poor survival. Figure S2. GSCs are enriched by IR-induced CLIP3 downregulation in GBM cells. Figure S3. Spy1-CLIP3 axis contributes to metabolic shift toward glycolysis in patient-derived GSCs. Figure S4. Spy1-CLIP3 Axis Contributes to Metabolic Shift toward Glycolysis in GBM Cells. Figure S5. Glimepiride Disrupts GSC Maintenance by CLIP3 Activation. Figure S6. Glimepiride inhibits glucose uptake and lactate production. Figure S7. Glimepiride hardly changes the body weight of GBM-bearing mice.

Published
2021
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18. Selective C3-alkenylation of oxindole with aldehydes using heterogeneous CeO2 catalyst

Author

Rashed, Md Nurnobi, Touchy, Abeda Sultana, Chaudhari, Chandan, Jeon, Jaewan, Siddiki, S. M. A. Hakim, 1000080775388, Toyao, Takashi, 1000060324000, Shimizu, Ken-ichi, Rashed, Md Nurnobi, Touchy, Abeda Sultana, Chaudhari, Chandan, Jeon, Jaewan, Siddiki, S. M. A. Hakim, 1000080775388, Toyao, Takashi, 1000060324000, and Shimizu, Ken-ichi

Abstract

We report herein that a commercially available CeO2 is an active and reusable catalyst for the C3-selective alkenylation of oxindole with aldehydes under solvent-free conditions. This. catalytic method is generally applicable to different aromatic and aliphatic aldehydes, giving 3-alkyledene-oxindoles in high yields (87%-99%) and high stereoselectivities (79%-93% to E-isomers). This is the first example of the catalytic synthesis of 3-alkenyl-oxindoles from oxindole and various aliphatic aldehydes. The Lewis acid-base interaction between Lewis acid sites on CeO2 and benzaldehyde was studied by in situ IR. The structure-activity relationship study using CeO2 catalysts with different sizes suggests that defect-free CeO2 surface is the active site for this reaction. (C) 2020, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

Published
2020

19. A Cu-Pd single-atom alloy catalyst for highly efficient NO reduction

Author

Xing, Feilong, Jeon, Jaewan, Toyao, Takashi, Shimizu, Ken-ichi, 1000010634983, Furukawa, Shinya, Xing, Feilong, Jeon, Jaewan, Toyao, Takashi, Shimizu, Ken-ichi, 1000010634983, and Furukawa, Shinya

Abstract

A series of Cu-Pd alloy nanoparticles supported on Al2O3 were prepared and tested as catalysts for deNO(x) reactions. XRD, HAADF-STEM, XAFS, and FT-IR analyses revealed that a single-atom alloy structure was formed when the Cu/Pd ratio was 5, where Pd atoms were well isolated by Cu atoms. Compared with Pd/Al2O3, Cu5Pd/Al2O3 exhibited outstanding catalytic activity and N-2 selectivity in the reduction of NO by CO: for the first time, the complete conversion of NO to N-2 was achieved even at 175 degrees C, with longterm stability for at least 30 h. High catalytic performance was also obtained in the presence of O-2 and C3H6 (model exhaust gas), where a 90% decrease in Pd use was achieved with minimum evolution of N2O. Kinetic and DFT studies demonstrated that N-O bond breaking of the (NO)(2) dimer was the rate-determining step and was kinetically promoted by the isolated Pd.

Published
2019

27. 54-2: Flexible a-IGZO TFT for Large Sized OLED TV

Author

Yoo, Won Beom, primary, Ha, Chanki, additional, Kwon, JinWoo, additional, Jeon, JaeWan, additional, Lee, HeungJo, additional, Kwon, SeYeoul, additional, Park, WeonSeo, additional, Kim, BongChul, additional, Shin, WooSup, additional, and Kim, JongWoo, additional

Published
2018
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29. LDR-Induced miR-30a and miR-30b Target the PAI-1 Pathway to Control Adverse Effects of NSCLC Radiotherapy

Author

Park, Gaeul, Son, Beomseok, Kang, JiHoon, Lee, Sungmin, Jeon, Jaewan, Kim, Joo-Hyung, Yi, Gi-Ra, Youn, HyeSook, Moon, Changjong, Nam, Seon Young, and Youn, BuHyun

Abstract

Radiotherapy has been a central part in curing non-small cell lung cancer (NSCLC). However, it is possible that not all of the tumor cells are destroyed by radiation; therefore, it is important to effectively control residual tumor cells that could become aggressive and resistant to radiotherapy. In this study, we aimed to investigate the molecular mechanism of decreased NSCLC radioresistance by low-dose radiation (LDR) pretreatment. The results indicated that miR-30a and miR-30b, which effectively inhibited plasminogen activator inhibitor-1 (PAI-1), were overexpressed by treatment of LDR to NSCLC cells. Phosphorylation of Akt and ERK, the downstream survival signals of PAI-1, was decreased by PAI-1 inhibition. Reduced cell survival and epithelial-mesenchymal transition by PAI-1 inhibition were confirmed in NSCLC cells. Moreover, in vivoorthotopic xenograft mouse models with 7C1 nanoparticles to deliver miRNAs showed that tumor growth and aggressiveness were efficiently decreased by LDR treatment followed by radiotherapy. Taken together, the present study suggested that PAI-1, whose expression is regulated by LDR, was critical for controlling surviving tumor cells after radiotherapy.

Published
2024
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30. Baiap3 regulates depressive behaviors in mice via attenuating dense core vesicle trafficking in subsets of prefrontal cortex neurons.

Author

Kim H, Kim J, Lee H, Shin E, Kang H, Jeon J, and Youn B

Abstract

Selective serotonin reuptake inhibitors (SSRIs) are effective first line therapies for treating depression, but are plagued by undesirable side effects and are not effective in all patients. Because SSRIs effectively deplete the neuronal releasable serotonin (5-HT) pool, gaining a deeper understanding of intracellular mechanisms regulating 5-HT pools can help us understand the shortcomings of SSRIs and develop more effective therapies. In this study, we found that BAIAP3 (brain-specific angiogenesis inhibitor 1-associated protein 3) is significantly downregulated in two mouse models of depression (the IR- and CUMS-induced depressive mouse models). In BAIAP3 downregulated models ( in vitro and in vivo ), we discovered that trafficking of dense core vesicle (DCV), organelles that store, transport and release cargo via exocytosis, was reduced. Accordingly, 5-HT exocytosis and levels in the synapse were lowered, causing defective post-synaptic neurotransmission. In a screen of natural products, we identified eucalyptol, the active components of Eucalyptus, as uniquely capable of increasing neuronal Baiap3 expression and elevate synaptic 5-HT levels. Moreover, eucalyptol treatment relieved depressive behavioral symptoms and restored serotonin levels in mice. Mechanistically, eucalyptol restores Baiap3 expression by reducing inhibitory microRNAs (miR-329, miR-362). These findings illuminate how Baiap3 depletion propagates neurotransmission dysfunction and point to eucalyptol as a novel agent for restoring serotonin exocytosis, suggesting potential for developing eucalyptol as a therapy for treating depression., Competing Interests: The authors declare no competing interest., (© 2021 The Authors.)

Published
2021
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