High-flux mixed matrix membranes containing bimetallic zeolitic imidazole framework-8 for C₃H₆/C₃H₈ separation

Oh, Jin Woo,Cho, Kie Yong,Kan, Ming-Yang,Yu, Hyun Jung,Kang, Dun-Yen,Lee, Jong Suk Elsevier 2020 Journal of membrane science Vol.596 No.-

<P><B>Abstract</B></P> <P>Membrane-based gas separation requires highly delicate engineering of molecular structures for the desired separation performance. Herein, a new efficient approach to fabricate high-flux mixed matrix membranes (MMMs) for C<SUB>3</SUB>H<SUB>6</SUB>/C<SUB>3</SUB>H<SUB>8</SUB> separation is reported by utilizing ZnCo-mixed hybrid zeolitic imidazolate framework-8 (ZIF-8-67) with unexpectedly large aperture size. Our structural characterizations in molecular level reveal that the ZIF-8-67 exhibits a larger aperture size compared to ZIF-8. Such a large aperture size of ZIF-8-67 is attributed to the large angle between two neighboring ligands and the long metal-ligand bonding distance, which is confirmed by refining the computed XRD pattern until it matches the experimental one (Rietveld refinement). More importantly, the inclusion of ZIF-8-67 in the 6FDA-DAM matrix enhances the C<SUB>3</SUB>H<SUB>6</SUB> permeability by up to 240% with the moderate C<SUB>3</SUB>H<SUB>6</SUB>/C<SUB>3</SUB>H<SUB>8</SUB> selectivity improvement (70%), as compared to those of the polymeric counterpart. Furthermore, the temperature-dependent transport characterization verifies that the ZIF-containing MMMs improve the C<SUB>3</SUB>H<SUB>6</SUB>/C<SUB>3</SUB>H<SUB>8</SUB> energetic selectivity at the sacrifice of entropic selectivity due to a unique molecular sieving behavior of the ZIFs, thereby enhancing the diffusivity selectivity. This study proposes a simple strategy to enable the fine-tuning of the aperture size of parent ZIFs towards the desired gas separation performance.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The effect of mixed metals of ZIFs on structure and transport properties was studied. </LI> <LI> Bimetallic ZnCo metal-mixed ZIF-8 (ZIF-8-67) exhibited an unexpected aperture size. </LI> <LI> ZIF-8-67-containing MMMs significantly enhanced C<SUB>3</SUB>H<SUB>6</SUB> permeability. </LI> <LI> ZIF-containing MMMs improved C<SUB>3</SUB>H<SUB>6</SUB>/C<SUB>3</SUB>H<SUB>8</SUB> energetic selectivity due to breathable behavior. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Analysis of Lettuce Growth, Gene Expression and Flavonoid Contents under LED Light Wavelength in Plant Factory system

Dae Hyun Kang,Maral Tsevelkhoroloo,Kwon Kyoo Kan,Myong Duc Kim,Yu Jin Jung 한국원예학회 2015 한국원예학회 학술발표요지 Vol.2015 No.5

A Three-step Proteolytic Cascade Mediates the Activation of the Peptidoglycan-induced Toll Pathway in an Insect

Kim, Chan-Hee,Kim, Su-Jin,Kan, Hongnan,Kwon, Hyun-Mi,Roh, Kyung-Baeg,Jiang, Rui,Yang, Yu,Park, Ji-Won,Lee, Hyeon-Hwa,Ha, Nam-Chul,Kang, Hee Jung,Nonaka, Masaru,Sö,derhä,ll, Kenneth,Lee, Bok Lu American Society for Biochemistry and Molecular Bi 2008 The Journal of biological chemistry Vol.283 No.12

<P>The recognition of lysine-type peptidoglycans (PG) by the PG recognition complex has been suggested to cause activation of the serine protease cascade leading to the processing of Spätzle and subsequent activation of the Toll signaling pathway. So far, two serine proteases involved in the lysine-type PG Toll signaling pathway have been identified. One is a modular serine protease functioning as an initial enzyme to be recruited into the lysine-type PG recognition complex. The other is the Drosophila Spätzle processing enzyme (SPE), a terminal enzyme that converts Spätzle pro-protein to its processed form capable of binding to the Toll receptor. However, it remains unclear how the initial PG recognition signal is transferred to Spätzle resulting in Toll pathway activation. Also, the biochemical characteristics and mechanism of action of a serine protease linking the modular serine protease and SPE have not been investigated. Here, we purified and cloned a novel upstream serine protease of SPE that we named SAE, SPE-activating enzyme, from the hemolymph of a large beetle, Tenebrio molitor larvae. This enzyme was activated by Tenebrio modular serine protease and in turn activated the Tenebrio SPE. The biochemical ordered functions of these three serine proteases were determined in vitro, suggesting that the activation of a three-step proteolytic cascade is necessary and sufficient for lysine-type PG recognition signaling. The processed Spätzle by this cascade induced antibacterial activity in vivo. These results demonstrate that the three-step proteolytic cascade linking the PG recognition complex and Spätzle processing is essential for the PG-dependent Toll signaling pathway.</P>

Loss of EMP2 Inhibits Melanogenesis of MNT1 Melanoma Cells via Regulation of TRP-2

Enkhtaivan Enkhmend,Kim Hyun Ji,Kim Boram,Byun Hyung Jung,Yu Lu,Nguyen Tuan Minh,Nguyen Thi Ha,Do Phuong Anh,Kim Eun Ji,Kim Kyung Sung,Huy Hiệu Phùng,Rahman Mostafizur,Jang Ji Yun,Rho Seung Bae,이호,Kan 한국응용약물학회 2022 Biomolecules & Therapeutics(구 응용약물학회지) Vol.30 No.2

Melanogenesis is the production of melanin from tyrosine by a series of enzyme-catalyzed reactions, in which tyrosinase and DOPA oxidase play key roles. The melanin content in the skin determines skin pigmentation. Abnormalities in skin pigmentation lead to various skin pigmentation disorders. Recent research has shown that the expression of EMP2 is much lower in melanoma than in normal melanocytes, but its role in melanogenesis has not yet been elucidated. Therefore, we investigated the role of EMP2 in the melanogenesis of MNT1 human melanoma cells. We examined TRP-1, TRP-2, and TYR expression levels during melanogenesis in MNT1 melanoma cells by gene silencing of EMP2. Western blot and RT-PCR results confirmed that the expression levels of TYR and TRP-2 were decreased when EMP2 expression was knocked down by EMP2 siRNA in MNT1 cells, and these changes were reversed when EMP2 was overexpressed. We verified the EMP2 gene was knocked out of the cell line (EMP2 CRISPR/Cas9) by using a CRISPR/Cas9 system and found that the expression levels of TRP-2 and TYR were significantly lower in the EMP2 CRISPR/Cas9 cell lines. Loss of EMP2 also reduced migration and invasion of MNT1 melanoma cells. In addition, the melanosome transfer from the melanocytes to keratinocytes in the EMP2 KO cells cocultured with keratinocytes was reduced compared to the cells in the control coculture group. In conclusion, these results suggest that EMP2 is involved in melanogenesis via the regulation of TRP-2 expression.

Comprehensive profiles and diagnostic value of menopausal-specific gut microbiota in premenopausal breast cancer

Hou Ming-Feng,Ou-Yang Fu,Li Chung-Liang,Chen Fang-Ming,Chuang Chieh-Han,Kan Jung-Yu,Wu Cheng-Che,Shih Shen-Liang,Shiau Jun-Ping,Kao Li-Chun,Kao Chieh-Ni,Lee Yi-Chen,Moi Sin-Hua,Yeh Yao-Tsung,Cheng Chi 생화학분자생물학회 2021 Experimental and molecular medicine Vol.53 No.-

In Western countries, breast cancer tends to occur in older postmenopausal women. However, in Asian countries, the proportion of younger premenopausal breast cancer patients is increasing. Increasing evidence suggests that the gut microbiota plays a critical role in breast cancer. However, studies on the gut microbiota in the context of breast cancer have mainly focused on postmenopausal breast cancer. Little is known about the gut microbiota in the context of premenopausal breast cancer. This study aimed to comprehensively explore the gut microbial profiles, diagnostic value, and functional pathways in premenopausal breast cancer patients. Here, we analyzed 267 breast cancer patients with different menopausal statuses and age-matched female controls. The α-diversity was significantly reduced in premenopausal breast cancer patients, and the β-diversity differed significantly between breast cancer patients and controls. By performing multiple analyses and classification, 14 microbial markers were identified in the different menopausal statuses of breast cancer. Bacteroides fragilis was specifically found in young women of premenopausal statuses and Klebsiella pneumoniae in older women of postmenopausal statuses. In addition, menopausal-specific microbial markers could exhibit excellent discriminatory ability in distinguishing breast cancer patients from controls. Finally, the functional pathways differed between breast cancer patients and controls. Our findings provide the first evidence that the gut microbiota in premenopausal breast cancer patients differs from that in postmenopausal breast cancer patients and shed light on menopausal-specific microbial markers for diagnosis and investigation, ultimately providing a noninvasive approach for breast cancer detection and a novel strategy for preventing premenopausal breast cancer.