Preparation of Octadecylamine-Graphene/MgCl₂-Supported Ziegler-Natta Catalyst and Its Application in Ethylene Polymerization

Zhang, Hao,Liu, Jing-Sheng,Zhang, He-Xin,Ko, Eun-Bin,Park, Jae-Hyeong,Moon, Young-Kwon,Shin, Byeong-Kwang,Zhang, Xue-Quan,Yoon, Keun-Byoung American Scientific Publishers 2018 Journal of Nanoscience and Nanotechnology Vol.18 No.4

<P>A facile coagglomeration method for preparing a long alkyl chain modified graphene oxide (MGO)/MgCl2-supported Ti-based Ziegler-Natta catalyst was reported. The effects of MGO on the catalyst morphology and activity for ethylene polymerization were examined. The resultant polyethylene (PE)/MGO nanocomposites exhibited a layered morphology, with the MGO fillers being well dispersed and exhibiting strong interfacial adhesion to the PE matrix. The thermal stability and mechanical properties of the PE were significantly enhanced with the introduction of a small amount of the MGO filler. Thus, this work provides a facile approach to the production of high-performance PE.</P>

Synthesis and Characterization of Polypropylene Alloys

Xue Quan Zhang,Chun Yu Zhang,Hong Guang Cai,Yu Xin Gao,Xiao Mei Lang,En Guang Zou,Lin Mei Wu 한국고분자학회 2009 한국고분자학회 학술대회 연구논문 초록집 Vol.2009 No.10

Facile preparation of functionalized MoS₂/polyethylene nanocomposites through in situ polymerization with MoS₂ containing Ziegler–Natta catalyst

Zhang, Hao,Moon, Young-Kwon,Zhang, Xue-Quan,Liu, Jing-Sheng,Zhang, He-Xin,Yoon, Keun-Byoung Pergamon Press 2017 European polymer journal Vol.87 No.-

<P><B>Abstract</B></P> <P>A facile method for preparing polyethylene (PE)/octadecylamine-functionalized MoS<SUB>2</SUB> (ODA-MoS<SUB>2</SUB>) nanocomposites through in situ polymerization with an ODA-MoS<SUB>2</SUB>-MgCl-TiCl<SUB>4</SUB> catalyst was developed. The catalyst was synthesized simply by the treatment of ODA-MoS<SUB>2</SUB> with a Grignard reagent, followed by anchoring of a TiCl<SUB>4</SUB> catalyst. The resulting catalyst exhibited higher activity toward ethylene polymerization than did an ODA-MoS<SUB>2</SUB>-free catalyst. After polymerization, the resultant PE/ODA-MoS<SUB>2</SUB> nanocomposites reproduced the catalyst morphology, showing a flaked morphology. In addition, the thermal stability and mechanical properties of PE were significantly enhanced by the introduction of ODA-MoS<SUB>2</SUB> fillers. These properties could result from the good dispersion and strong interfacial adhesion of ODA-MoS<SUB>2</SUB> fillers and the PE matrix.</P> <P><B>Highlights</B></P> <P> <UL> <LI> PE/ODA-MoS<SUB>2</SUB> nanocomposites were successful synthesized through in-situ polymerization. </LI> <LI> The resultant nanocomposites had a layered morphology. </LI> <LI> The ODA-MoS<SUB>2</SUB> fillers well dispersed in the PE matrix with strong interfacial adhesion. </LI> <LI> The thermal stability and mechanical properties of PE were significantly enhanced with the addition of ODA-MoS<SUB>2</SUB>. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Nano La2O3 as a heterogeneous catalyst for biodiesel synthesis by transesterification of Jatropha curcas L. oil

Quan Zhou,Song Yang,Heng Zhang,Fei Chang,Hu Li,Hu Pan,Wei Xue,De-Yu Hu 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.31 No.-

A comparative study on the activity of La2O3 and two kinds of nano La2O3 catalysts prepared usingsonochemical (nano La2O3-S) and hydrothermal methods in the transesterification to produce biodieselwas conducted. The relatively high activity of nano La2O3 catalysts may be ascribed to their high basestrength, large base amount, small particle size and large BET surface areas. Nano La2O3-S was selectedfor further optimisation due to its simple preparation procedure and short preparation time. The FAMEcontent and yield obtained were successively 97.6% and 90.3% under optimal conditions. Moreover, nanoLa2O3-S showed a remarkable tolerance to FFA.

Temporal and spatial impact of Spartina alterniflora invasion on methanogens community in Chongming Island, China

Xue Ping Chen,Jing Sun,Yi Wang,Heng Yang Zhang,Chi Quan He,Xiao Yan Liu,Nai Shun Bu,Xi-En Long 한국미생물학회 2018 The journal of microbiology Vol.56 No.7

Methane production by methanogens in wetland is recognized as a significant contributor to global warming. Spartina alterniflora (S. alterniflora), which is an invasion plant in China’s wetland, was reported to have enormous effects on methane production. But studies on shifts in the methanogen community in response to S. alterniflora invasion at temporal and spatial scales in the initial invasion years are rare. Sediments derived from the invasive species S. alterniflora and the native species Phragmites australis (P. australis) in pairwise sites and an invasion chronosequence patch (4 years) were analyzed to investigate the abundance and community structure of methanogens using quantitative real-time PCR (qPCR) and Denaturing gradient gel electrophoresis (DGGE) cloning of the methyl-coenzyme M reductase A (mcrA) gene. For the pairwise sites, the abundance of methanogens in S. alterniflora soils was lower than that of P. australis soils. For the chronosequence patch, the abundance and diversity of methanogens was highest in the soil subjected to two years invasion, in which we detected some rare groups including Methanocellales and Methanococcales. These results indicated a priming effect at the initial invasion stages of S. alterniflora for microorganisms in the soil, which was also supported by the diverse root exudates. The shifts of methanogen communities after S. alterniflora invasion were due to changes in pH, salinity and sulfate. The results indicate that root exudates from S. alterniflora have a priming effect on methanogens in the initial years after invasion, and the predominate methylotrophic groups (Methanosarcinales) may adapt to the availability of diverse substrates and reflects the potential for high methane production after invasion by S. alterniflora.

NADH-dependent butanol dehydrogenase from Fusobacterium nucleatum: purification, crystallization, and X-ray crystallographic analysis

Xue Bai,Jing Lan,Shanru He,Tingting Bu,Jie Zhang,Lulu Wang,Chunshan Quan,Ki Hyun Nam,Nam-Chul Ha,Yongbin Xu 한국구조생물학회 2022 Biodesign Vol.10 No.2

Fusobacterium nucleatum is a dangerous pathogen, and it has been linked to a variety of health problems, including cancer, periodontal disease, and pregnancy complications. F. nucleatum butanol dehydrogenase (FnYqdH) is a group of dehydrogenase enzymes that facilitate interconversion between butyraldehyde and butanol at the expenditure of a cofactor NAD (P)H. In this study, FnYqdH was successfully expressed and purified using Ni-NTA affinity, Q anionexchange, and gel-filtration chromatography. The protein crystal was obtained and diffracted to a resolution of 2.0 Å. The crystal belonged to the orthorhombic space group of I222, with unit-cell parameters of a = 64.77, b = 78.85, and c = 215.22 Å. The Matthews coefficient and solvent content were estimated to be 3.19 Å3 Da–1 and 61.49%, respectively, assuming that the asymmetric unit contained only one recombinant protein molecule. Size-exclusion chromatography suggested that FnYqdH prefers to exist as a dimer in the solution.

Expression and Function of GSTA1 in Lung Cancer Cells

Pan, Xue-Diao,Yang, Zhou-Ping,Tang, Qi-Ling,Peng, Tong,Zhang, Zheng-Bing,Zhou, Si-Gui,Wang, Gui-Xiang,He, Bing,Zang, Lin-Quan Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.20

Glutathione S-transferase A1 (GSTA1) appears to be primarily involved in detoxification processes, but possible roles in lung cancer remain unclear. The objective of this study was to investigate the expression and function of GSTA1 in lung cancer cells. Real-time PCR and Western blotting were performed to assess expression in cancer cell lines and the normal lung cells, then verify the A549 cells line with stable overexpression. Localization of GSTA1 proteins was assessed by cytoimmunofluorescence. Three double-strand DNA oligoRNAs (SiRNAs) were synthesized prior to being transfected into A549 cells with Lipofectamine 2000, and then the most efficient SiRNA was selected. Expression of the GSTA1 gene in the transfected cells was determined by real-time PCR and Western blotting. The viability of the transfected cells were assessed by MTT. Results showed that the mRNA and protein expression of A549 cancer cells was higher than in MRC-5 normal cells. Cytoimmunofluorescence demonstrated GSTA1 localization in the cell cytoplasm and/or membranes. Transfection into A549 cells demonstrated that down-regulated expression could inhibit cell viability. Our data indicated that GSTA1 expression may be a target molecule in early diagnosis and treatment of lung cancer.

Isolation of Probiotic Piliated Lactobacillus rhamnosus Strains from Human Fecal Microbiota Using SpaA Antiserum-Based Colony Immunoblotting

( Zhen-quan Yang ),( Yu Xue ),( Sheng-qi Rao ),( Mi Zhang ),( Lu Gao ),( Yong-qi Yin ),( Da-wei Chen ),( Xiao-hui Zhou ),( Xin-an Jiao ) 한국미생물생명공학회(구 한국산업미생물학회) 2017 Journal of microbiology and biotechnology Vol.27 No.11

Piliated Lactobacillus rhamnosus (pLR) strains possess higher adherent capacity than non-piliated strains. The objective of this study was to isolate and characterize probiotic pLR strains in human fecal samples. To this end, mouse polyclonal antiserum (anti-SpaA) against the recombinant pilus protein (SpaA) of L. rhamnosus strain GG (LGG) was prepared and tested for its reactivity and specificity. With the anti-SpaA, a method combining the de Man, Rogosa, and Sharpe (MRS) agar plating separation and colony immunoblotting (CIB) was developed to isolate pLR from 124 human fecal samples. The genetic and phenotypic characteristics of the resultant pLR isolates were compared by randomly amplified polymorphic DNA (RAPD) fingerprinting, and examination of adhesion to Caco-2 cells, hydrophobicity, autoaggregation, and in vitro gastrointestinal tolerance. Anti-SpaA specifically reacted with three pLR strains of 25 test strains, as assessed by western blotting, immunofluorescence flow cytometry, and immunoelectron microscopy (IEM) assays. The optimized MRS agar separation plus anti- SpaA-based CIB procedure could quantitatively detect 2.5 × 10³ CFU/ml of pLR colonies spiked in 10⁶ CFU/ml of background bacteria. Eight pLR strains were identified in 124 human fecal samples, and were confirmed by 16S RNA gene sequencing and IEM identification. RAPD fingerprinting of the pLR strains revealed seven different patterns, of which only two isolates from infants showed the same RAPD profiles with LGG. Strain PLR06 was obtained with high adhesion and autoaggregation activities, hydrophobicity, and gastrointestinal tolerance. Anti-SpaA-based CIB is a rapid and inexpensive method for the preliminary screening of novel adherent L. rhamnosus strains for commercial purposes.

Clostridium beijerinckii glyceraldehyde-3-phosphate dehydrogenase GAPDH: purification, crystallization, and X-ray crystallographic analysis

Jie Zhang,Yuanyuan Chen,Tingting Bu,Xue Bai,Shanru He,Lulu Wang,Chunshan Quan,Yongbin Xu 한국구조생물학회 2022 Biodesign Vol.10 No.3

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a ubiquitous and highly abundant glycolytic enzyme. It plays a pivotal role for the energy and carbon metabolism of most organisms including industrial bacteria. It catalyzes the two step oxidative phosphorylation of D-glyceraldehyde-3-phosphate into 1,3-bisphosphoglycerate using inorganic phosphate and nicotinamide adenine dinucleotide (NAD+) as cofactor. In this study, GAPDH from C. beijerinckii (CbGAPDH) was successfully expressed and purified using Ni-NTA affinity, Q anion-exchange, and gel-filtration chromatography. The protein crystal was obtained and diffracted to a resolution of 1.60 Å. The crystal belonged to the hexagonal space group P6222, with unit-cell parameters of a = 120.6, b = 120.6, and c = 122.1 Å. The Matthews coefficient and solvent content were estimated to be 3.50 Å3 Da–1 and 64.90%, respectively, assuming that the asymmetric unit contained only one recombinant protein molecule.

MEKK3 and Survivin Expression in Cervical Cancer: Association with Clinicopathological Factors and Prognosis

Cao, Xue-Quan,Lu, Hong-Sheng,Zhang, Ling,Chen, Li-Li,Gan, Mei-Fu Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.13

Mitogen-activated protein kinase/extracellular signal-regulated kinase kinase kinase 3 (MEKK3) is an important protein kinase and a member of the MAPK family, which regulates cellular responses to environmental stress and serves as key integration points along the signal transduction cascade that not only link diverse extracellular stimuli to subsequent signaling molecules but also amplify the initiating signals to ultimately activate effector molecules and induce cell proliferation, differentiation and survival. To explore the relationship between MEKK3 and cell apoptosis, clinicopathology and prognosis, we characterize the expression of MEKK3 and survivin in cervical cancer. MEKK3 and survivin expression was measured by RT-PCR and Western blotting of fresh surgical resections from 30 cases of cervical cancer and 25 cases of chronic cervicitis. Protein expression was detected by tissue microarray and immunochemistry (En Vision) in 107 cases of cervical cancer, 86 cases of cervical intraepithelial neoplasia (CIN), and 35 cases of chronic cervicitis. Expression patterns were analyzed for their association with clinicopathological factors and prognosis in cervical cancer. Expression of MEKK3 and survivin mRNA was significantly higher in cervical cancer than in the controls (p<0.05). MEKK3 and survivin expression differed significantly between cervical carcinoma, CIN, and cervicitis (p<0.05) and correlated with clinical stage, infiltration depth, and lymph node metastasis (p<0.05). MEKK3 expression was positively correlated with survivin (p<0.05). Kaplan-Meier survival analysis showed that MEKK3 and survivin expression, lymph node metastasis, depth of invasion, and FIGO stage reduce cumulative survival. Cox multivariate regression analysis showed that MEKK3, survivin, and clinical staging are independent prognostic factors in cervical cancer (p<0.05). Expression of MEKK3 and survivin are significantly increased in cervical cancer, their overexpression participating in the occurrence and development of cervical cancer, with protein expression and clinical staging acting as independent prognostic factors for patients with cervical cancer.