Publications by authors named "Moon Joo Lee"

7 Publications

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MOF-Based Membranes for Gas Separations.

Chem Rev 2020 Aug 1;120(16):8161-8266. Epub 2020 Jul 1.

Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.

Metal-organic frameworks (MOFs) represent the largest known class of porous crystalline materials ever synthesized. Their narrow pore windows and nearly unlimited structural and chemical features have made these materials of significant interest for membrane-based gas separations. In this comprehensive review, we discuss opportunities and challenges related to the formation of pure MOF films and mixed-matrix membranes (MMMs). Common and emerging separation applications are identified, and membrane transport theory for MOFs is described and contextualized relative to the governing principles that describe transport in polymers. Additionally, cross-cutting research opportunities using advanced metrologies and computational techniques are reviewed. To quantify membrane performance, we introduce a simple membrane performance score that has been tabulated for all of the literature data compiled in this review. These data are reported on upper bound plots, revealing classes of MOF materials that consistently demonstrate promising separation performance. Recommendations are provided with the intent of identifying the most promising materials and directions for the field in terms of fundamental science and eventual deployment of MOF materials for commercial membrane-based gas separations.
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http://dx.doi.org/10.1021/acs.chemrev.0c00119DOI Listing
August 2020

High-Flux Zeolitic Imidazolate Framework Membranes for Propylene/Propane Separation by Postsynthetic Linker Exchange.

Angew Chem Int Ed Engl 2018 01 5;57(1):156-161. Epub 2017 Dec 5.

Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX, 77843-3122, USA.

While zeolitic imidazolate framework, ZIF-8, membranes show impressive propylene/propane separation, their throughput needs to be greatly improved for practical applications. A method is described that drastically reduces the effective thickness of ZIF-8 membranes, thereby substantially improving their propylene permeance (that is, flux). The new strategy is based on a controlled single-crystal to single-crystal linker exchange of 2-methylimidazole in ZIF-8 membrane grains with 2-imidazolecarboxaldehyde (ZIF-90 linker), thereby enlarging the effective aperture size of ZIF-8. The linker-exchanged ZIF-8 membranes showed a drastic increase in propylene permeance by about four times, with a negligible loss in propylene/propane separation factor when compared to as-prepared membranes. The linker-exchange effect depends on the membrane synthesis method.
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http://dx.doi.org/10.1002/anie.201708924DOI Listing
January 2018

p62/SQSTM1 is required for the protection against endoplasmic reticulum stress-induced apoptotic cell death.

Free Radic Res 2016 Dec 23;50(12):1408-1421. Epub 2016 Nov 23.

a Severance Biomedical Science Institute , Yonsei Biomedical Research Institute, Yonsei University College of Medicine , Seoul , Republic of Korea.

Endoplasmic reticulum (ER) stress is triggered by various cellular stresses that disturb protein folding or calcium homeostasis in the ER. To cope with these stresses, ER stress activates the unfolded protein response (UPR) pathway, but unresolved ER stress induces reactive oxygen species (ROS) accumulation leading to apoptotic cell death. However, the mechanisms that underlie protection from ER stress-induced cell death are not clearly defined. The nuclear factor erythroid 2-related factor 2 (Nrf2)-Kelch-like ECH-associated protein 1 (Keap1) pathway plays a crucial role in the protection of cells against ROS-mediated oxidative damage. Keap1 acts as a negative regulator of Nrf2 activation. In this study, we investigated the role of the Nrf2-Keap1 pathway in protection from ER stress-induced cell death using tunicamycin (TM) as an ER stress inducer. We found that Nrf2 is an essential protein for the prevention from TM-induced apoptotic cell death and its activation is driven by autophagic Keap1 degradation. Furthermore, ablation of p62, an adapter protein in the autophagy process, attenuates the Keap1 degradation and Nrf2 activation that was induced by TM treatment, and thereby increases susceptibility to apoptotic cell death. Conversely, reinforcement of p62 alleviated TM-induced cell death in p62-deficient cells. Taken together, these results demonstrate that p62 plays an important role in protecting cells from TM-induced cell death through Nrf2 activation.
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http://dx.doi.org/10.1080/10715762.2016.1253073DOI Listing
December 2016

Ezetimibe, an NPC1L1 inhibitor, is a potent Nrf2 activator that protects mice from diet-induced nonalcoholic steatohepatitis.

Free Radic Biol Med 2016 10 12;99:520-532. Epub 2016 Sep 12.

Severance Biomedical Science Institute, Yonsei Biomedical Research Institute, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea. Electronic address:

Oxidative stress is important for the pathogenesis of nonalcoholic fatty liver disease (NAFLD), a chronic disease that ranges from hepatic steatosis to nonalcoholic steatohepatitis (NASH). The nuclear factor erythroid 2-related factor 2-Kelch-like ECH associated protein 1 (Nrf2-Keap1) pathway is essential for cytoprotection against oxidative stress. In this study, we found that oxidative stress or inflammatory biomarkers and TUNEL positive cells were markedly increased in NASH patients compared to normal or simple steatosis. In addition, we identified that the hepatic mRNA levels of Nrf2 target genes such as Nqo-1 and GSTA-1 were significantly increased in NASH patients. Ezetimibe, a drug approved by the Food and Drug Administration for the treatment of hypercholesterolemia, improves NAFLD and alleviates oxidative stress. However, the precise mechanism of its antioxidant function remains largely unknown. We now demonstrate that ezetimibe activates Nrf2-Keap1 pathway which was dependent of autophagy adaptor protein p62, without causing cytotoxicity. Ezetimibe activates AMP-activated protein kinase (AMPK), which in turn phosphorylates p62 (p-S351) via their direct interaction. Correspondingly, Ezetimibe protected liver cells from saturated fatty acid-induced apoptotic cell death through p62-dependent Nrf2 activation. Furthermore, its role as an Nrf2 activator was supported by methione- and choline- deficient (MCD) diet-induced NASH mouse model, showing that ezetimibe decreased the susceptibility of the liver to oxidative injury. These data demonstrate that the molecular mechanisms underlying ezetimibe's antioxidant role in the pathogenesis of NASH.
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http://dx.doi.org/10.1016/j.freeradbiomed.2016.09.009DOI Listing
October 2016

Soluble, microporous, Tröger's Base copolyimides with tunable membrane performance for gas separation.

Chem Commun (Camb) 2016 Mar;52(19):3817-20

Department of Energy Engineering, College of Engineering, Hanyang University, Seoul 04763, Republic of Korea.

A facile two-step synthesis beginning with commercial monomers to prepare copolyimides by Tröger's Base (TB) formation provides membranes for the first time with tunable gas transport relative to hydrogen separations, CO2 plasticization resistance, and good mechanical and thermal properties.
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http://dx.doi.org/10.1039/c5cc09783eDOI Listing
March 2016

Correction: Highly lithium-ion conductive battery separators from thermally rearranged polybenzoxazole.

Chem Commun (Camb) 2015 Feb;51(16):3474

School of Chemical Engineering, College of Engineering, Hanyang University, Seoul 133-791, Korea.

Correction for 'Highly lithium-ion conductive battery separators from thermally rearranged polybenzoxazole' by Moon Joo Lee et al., Chem. Commun., 2015, 51, 2068-2071.
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http://dx.doi.org/10.1039/c5cc90064fDOI Listing
February 2015

Highly lithium-ion conductive battery separators from thermally rearranged polybenzoxazole.

Chem Commun (Camb) 2015 Feb;51(11):2068-71

School of Chemical Engineering, College of Engineering, Hanyang University, Seoul 133-791, Korea.

High power density lithium ion battery (HLIB) separators were fabricated for the first time from thermally rearranged poly(benzoxazole-co-imide) (TR-PBOI) nanofibrous membranes coated with TR-PBOI nanoparticles, which show distinct thermal and dimensional stabilities as well as excellent cycle retention and rate capability.
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http://dx.doi.org/10.1039/c4cc09411eDOI Listing
February 2015