Enhancing the CO₂ separation performance of polymer membranes via the incorporation of amine-functionalized HKUST-1 nanocrystals

Chuah, Chong Yang,Li, Wen,Samarasinghe, S.A.S.C.,Sethunga, G.S.M.D.P.,Bae, Tae-Hyun Elsevier 2019 Microporous and mesoporous materials Vol.290 No.-

<P><B>Abstract</B></P> <P>HKUST-1 nanocrystals with large accessible surface areas and high porosity were functionalized with amine groups and incorporated into polymer matrices to form mixed-matrix membranes for application in CO<SUB>2</SUB> capture. This gas permeation study reveals that pristine HKUST-1 nanocrystals are able to increase the gas permeabilities of polymer membranes with no noticeable effect on CO<SUB>2</SUB>/N<SUB>2</SUB> selectivity as a result of their high porosity and large pore dimensions. Contrarily, 20 wt% amine-functionalized HKUST-1 can improve the CO<SUB>2</SUB>/N<SUB>2</SUB> selectivity of polymer membranes by as much as 38%. As shown in a detailed analysis of the diffusivity-solubility, the amine-functionalized HKUST-1 suppressed N<SUB>2</SUB> solubility and diffusivity but enhanced CO<SUB>2</SUB> diffusivity. This resulted in an increased CO<SUB>2</SUB>/N<SUB>2</SUB> perm-selectivity. Meanwhile, the pristine HKUST-1 nanocrystals increased the diffusivity and solubility of both species in a non-selective manner. These results indicate the feasibility of tuning the CO<SUB>2</SUB> separation performance of mixed-matrix membranes by introducing amine functionality into the filler.</P> <P><B>Highlights</B></P> <P> <UL> <LI> HKUST-1 and amine-functionalized HKUST-1 nanocrystals were successfully synthesized. </LI> <LI> HKUST-1 nanocrystals improved CO<SUB>2</SUB> permeability with no effect on CO<SUB>2</SUB> selectivity. </LI> <LI> Amine-functionalized HKUST-1 enhanced CO<SUB>2</SUB>/N<SUB>2</SUB> selectivity and CO<SUB>2</SUB> permeability. </LI> <LI> Amine-functionalized HKUST-1 suppressed N<SUB>2</SUB> solubility and diffusivity substantially. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Isolation, Purification, and Structural Identification of an Antifungal Compound from a Trichoderma Strain

( Chong Wei Li ),( Rui Qing Song ),( Li Bin Yang ),( Xun Deng ) 한국미생물 · 생명공학회 2015 Journal of microbiology and biotechnology Vol.25 No.8

Trichoderma strain T-33 has been demonstrated to have inhibitory effect on the fungus species Cytospora chrysosperma. Here, an active antifungal compound was obtained from Trichoderma strain T-33 extract via combined separation technologies, including organic solvent extraction, liquid chromatography, and thin-layer chromatography. The purified compound was further characterized by advanced analytical technologies to elucidate its chemical structure. Results indicated that the active antifungal compound in Trichoderma strain T-33 extract is 2,5-cyclohexadiene-1,4-dione-2,6-bis (1,1-dimethylethyl).

Induction Chemotherapy Plus Concurrent Chemoradiotherapy versus Concurrent Chemoradiotherapy Alone in Locoregionally Advanced Nasopharyngeal Carcinoma in Children and Adolescents: A Matched Cohort Analysis

Yang Li,Lin-Quan Tang,Li-Ting Liu,Shan-Shan Guo,Yu-Jing Liang,Xue-Song Sun,Qing-Nan Tang,Jin-Xin Bei,Jing Tan,Shuai Chen,Jun Ma,Chong Zhao,Qiu-Yan Chen,Hai-Qiang Mai 대한암학회 2018 Cancer Research and Treatment Vol.50 No.4

Purpose The purpose of this study was to evaluate the long-term clinical outcome and toxicity of induction chemotherapy (IC) followed by concomitant chemoradiotherapy (CCRT) compared with CCRT alone for the treatment of children and adolescent locoregionally advanced nasopharyngeal carcinoma (LACANPC). Materials and Methods A total of 194 locoregionally advanced nasopharyngeal carcinoma patients younger than 21 years who received CCRT with or without IC before were included in the study population. Overall survival (OS) rate, progression-free survival (PFS) rate, locoregional recurrence-free survival (LRFS) rate, and distant metastasis-free survival (DMFS) rate were assessed by the Kaplan-Meier method and a log-rank test. Treatment toxicities were clarified and compared between two groups. Results One hundred and thiry of 194 patients received IC+CCRT. Patients who were younger and with more advanced TNM stage were more likely to receive IC+CCRT and intensive modulated radiotherapy. The addition of IC before CCRT failed to improve survival significantly. The matched analysis identified 43 well-balanced patients in both two groups. With a median follow-up of 51.5 months, no differences were found between the IC+CCRT group and the CCRT group in 5-year OS (83.7% vs. 74.6%, p=0.153), PFS (79.2% vs. 73.4%, p=0.355), LRFS (97.7% vs. 88.2%, p=0.083), and DMFS (81.6% vs. 81.6%, p=0.860). N3 was an independent prognostic factor predicting poorer OS, PFS, and DMFS. The addition of IC was associated with increased rates of grade 3 to 4 neutropenia. Conclusion This study failed to demonstrate that adding IC before CCRT could provide a significant additional survival benefit for LACANPC patients. Further investigations are warranted.

Sparse multivariate autoregressive modeling for mild cognitive impairment classification.

Li, Yang,Wee, Chong-Yaw,Jie, Biao,Peng, Ziwen,Shen, Dinggang Humana Press, Inc 2014 Neuroinformatics Vol.12 No.3

<P>Brain connectivity network derived from functional magnetic resonance imaging (fMRI) is becoming increasingly prevalent in the researches related to cognitive and perceptual processes. The capability to detect causal or effective connectivity is highly desirable for understanding the cooperative nature of brain network, particularly when the ultimate goal is to obtain good performance of control-patient classification with biological meaningful interpretations. Understanding directed functional interactions between brain regions via brain connectivity network is a challenging task. Since many genetic and biomedical networks are intrinsically sparse, incorporating sparsity property into connectivity modeling can make the derived models more biologically plausible. Accordingly, we propose an effective connectivity modeling of resting-state fMRI data based on the multivariate autoregressive (MAR) modeling technique, which is widely used to characterize temporal information of dynamic systems. This MAR modeling technique allows for the identification of effective connectivity using the Granger causality concept and reducing the spurious causality connectivity in assessment of directed functional interaction from fMRI data. A forward orthogonal least squares (OLS) regression algorithm is further used to construct a sparse MAR model. By applying the proposed modeling to mild cognitive impairment (MCI) classification, we identify several most discriminative regions, including middle cingulate gyrus, posterior cingulate gyrus, lingual gyrus and caudate regions, in line with results reported in previous findings. A relatively high classification accuracy of 91.89 % is also achieved, with an increment of 5.4 % compared to the fully-connected, non-directional Pearson-correlation-based functional connectivity approach.</P>

Preparation of Monodisperse Colloidal ZnO Nanoparticles and Their Optical Properties

Chong Yang,Limei Tang,Qingsong Li,Ailing Bai,Yanqiu Wang,Yingmin Yu 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2015 NANO Vol.10 No.5

Monodisperse colloidal zinc oxide (ZnO) nanospheres with a narrow size distribution were synthesized via a developed two-stage solution method. We controlled the size of the as-synthesized ZnO nanoparticles by varying the amount of ZnO/ethanol suspension added. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) revealed that the diameter of the as-synthesized ZnO nanoparticles was in the range of 60 – 140 nm with a polydispersity index less than 5%. On high-resolution TEM images, we clearly observed that the ZnO nanospheres were actually composed of tiny ZnO subunits, several nanometers in size. Powder X-ray diffraction and TEM-selected area electron diffraction analysis showed that the spheres consisted of polycrystalline nanoparticles. The size of the subunits, which was confirmed by ultraviolet (UV)-visible spectroscopy, increased as the amount of ZnO/ethanol suspension added was decreased. A UV emission at about 374 nm was observed, and this emission of ZnO nanoparticles is found to depend on particle size due to the confinement effect. A red emission at about 651 nm, which has been reported for undoped ZnO, appeared due to the excess oxygen on the particles from O – H or C=O groups. The intensity of the red emission increased as the relative oxygen content increased. The formation mechanism of such ZnO nanospheres was also considered.

MiR-29a and MiR-140 Protect Chondrocytes against the Anti-Proliferation and Cell Matrix Signaling Changes by IL-1β

Li, Xianghui,Zhen, Zhilei,Tang, Guodong,Zheng, Chong,Yang, Guofu Korean Society for Molecular and Cellular Biology 2016 Molecules and cells Vol.39 No.2

As a degenerative joint disease, osteoarthritis (OA) constitutes a major cause of disability that seriously affects the quality of life of a large population of people worldwide. However, effective treatment that can successfully reverse OA progression is lacking until now. The present study aimed to determine whether two small non-coding RNAs miR-29a and miR-140, which are significantly down-regulated in OA, can be applied together as potential therapeutic targets for OA treatment. MiRNA synergy score was used to screen the miRNA pairs that potentially synergistically regulate OA. An in vitro model of OA was established by treating murine chondrocytes with IL-$1{\beta}$. Transfection of miR-29a and miR-140 via plasmids was investigated on chondrocyte proliferation and expression of nine genes such as ADAMTS4, ADAMTS5, ACAN, COL2A1, COL10A1, MMP1, MMP3, MMP13 and TIMP metallopeptidase inhibitor 1 (TIMP1). Western blotting was used to determine the protein expression level of MMP13 and TIMP1, and ELISA was used to detect the content of type II collagen. Combined use of miR-29a and miR-140 successfully reversed the destructive effect of IL-$1{\beta}$ on chondrocyte proliferation, and notably affected the MMP13 and TIMP1 gene expression that regulates extracellular matrix. Although co-transfection of miR-29a and miR-140 did not show a synergistic effect on MMP13 protein expression and type II collagen release, but both of them can significantly suppress the protein abundance of MMP13 and restore the type II collagen release in IL-$1{\beta}$ treated chondrocytes. Compared with single miRNA transfection, cotransfection of both miRNAs exceedingly abrogated the suppressed the protein production of TIMP1 caused by IL-$1{\beta}$, thereby suggesting potent synergistic action. These results provided1novel insights into the important function of miRNAs' collaboration in OA pathological development. The reduced MMP13, and enhanced TIMP1 protein production and type II collagen release also implies that miR-29a and miR-140 combination treatment may be a possible treatment for OA.

A Novel Measurement Approach for The Half-wave Voltage of Phase Modulator based on PM-MZI Photonic Link

Li Xianghua,Ye Quanyi,Chong Yuhua,Zhou Zhenghua,Yang Chun 한국광학회 2014 Current Optics and Photonics Vol.18 No.3

This paper presents a new method for measuring the half-wave voltage Vπ of an electro-optic phase modulator based on a phase-modulated photonic link with interferometric demodulation. By using this method, the Vπ can be obtained with the RF voltage amplitude input required to achieve 1-dB gain compression of link and the differential delay of a Mach-Zehnder interferometer. We measure the Vπ of a commercial phase modulator by using the presented method and the carrier/the first sideband intensity ratio method. Furthermore, we compare the two measurements with the typical value provided by the manufacturer. The experiment shows that this novel measurement method is feasible, straightforward, and accurate.

Dynamic Range Improvement of IM-DD Optical Link using Dual-Wavelength Dual-Parallel Modulation

Li Xianghua,Zhou Zhenghua,Chong Yuhua,Yang Chun 한국광학회 2014 Current Optics and Photonics Vol.18 No.4

In this paper, we present an incoherent dual-parallel modulation linearized optical link employing two different optical wavelengths. Comparing with previous dual-parallel modulation, this linearization method prevents the recreation of distortion products and can be readily implemented. Furthermore, a dual-wavelength dual-parallel modulation linearized optical link constructed with the commercially available devices is experimentally demonstrated with a spurious-free dynamic range of 122.5 dB.Hz4/5. More than 25 dB suppression of the intermodulation distortion, 15.6 dB improvement of spurious-free dynamic range and 1.5 dB improvement of compression dynamic range are achieved after linearization.

Cooling Water Jacket Design and Fluid-Solid Coupling Heat Transfer Analysis of Oil-Gas Mixed Transmission Twin-Screw Pump Under High Gas Volume Fraction

Li Wang,Xuejing Zhang,JunHu Yang,Chong Ma,Wei Han,Yubing Gong 한국유체기계학회 2023 International journal of fluid machinery and syste Vol.16 No.2

When GVF in the inlet of the oil-gas mixed transmission twin-screw pump is high, the temperature difference between the inlet and outlet of the screw pump will rise significantly, and rotor expansion jam will occur. To prevent the expansion jam caused by the overheating of the screw pump, the cooling water jacket is designed for gas-liquid mixed screw pump with high GVF to continuously cool. Using the theory of fluid-structure interaction heat transfer, the cooling effect of the cooling water jacket of the equal pitch screw pump and the variable pitch screw pump is numerically calculated, and after comparison with the experiment, it finds that the maximum deviation of the outlet temperature of the variable pitch screw pump does not exceed 4K and the average deviation is about 6 %. When GVF is 96%, the calculation of the cooling water cavity shows that the average temperature drop of the liner after the cooling of the equal pitch screw pump and the variable pitch screw pump is about 4K and 3K, respectively. When GVF rises from 90% to 99%, the average temperature drop is about 3.5K. Cooling water jacket has obvious cooling effect on screw pump with high GVF.

CONTROL SYSTEM OF THREE DIMENSIONAL HYDRAULIC SIMULATIVE ROCKING TEST-BED

Chong Li Jiang,Wei Dong Ye,Dong Ming,Hai Yang Zhou,Xiao Hui Wang 대한전자공학회 1992 대한전자공학회 Conference Vol.1992 No.2