A large-area free-standing graphene oxide multilayer membrane with high stability for nanofiltration applications

Chen, Long,Li, Yanhui,Chen, Lina,Li, Na,Dong, Chenglong,Chen, Qiong,Liu, Beibei,Ai, Qing,Si, Pengchao,Feng, Jinkui,Zhang, Lin,Suhr, Jonghwan,Lou, Jun,Ci, Lijie Elsevier 2018 CHEMICAL ENGINEERING JOURNAL -LAUSANNE- Vol.345 No.-

<P><B>Abstract</B></P> <P>A flexible and free-standing graphene oxide and nylon 6 (GO@nylon 6) multilayer nanofiltration membrane was prepared by a layer-by-layer assembly process. The combination of electrospinning and electrospraying technique was employed, which can facilely prepare large-area membrane with size of 20 × 30 cm. The mechanical stability of multilayer membrane has enhanced significantly due to the tightly locked structure achieved by nylon 6 nanofibers network. The novel GO@nylon 6–13 multilayer nanofiltration membrane demonstrated a pure water flux up to 11.15 L m<SUP>−2</SUP> h<SUP>−1</SUP> bar<SUP>−1</SUP>, while keeping high organic dye rejection rate (>95% for methylene blue, and >99% for methyl orange). The rejections rate of the Na<SUB>2</SUB>SO<SUB>4</SUB>, NaCl, CuSO<SUB>4</SUB>, and Pb(NO<SUB>3</SUB>)<SUB>2</SUB> were 56.5%, 27.6%, 36.7%, and 18.9%, respectively. Furthermore, GO@nylon 6–13 multilayer nanofiltration membrane also demonstrated a high flux of some common organic solvents (8.4, 5.3, and 0.8 L m<SUP>−2</SUP> h<SUP>−1</SUP> bar<SUP>−1</SUP> for methanol, ethanol, and NMP, respectively), showing excellent chemical stability for separation process in those solvents.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Large-area GO@nylon 6 multilayer nanofiltration membrane was prepared. </LI> <LI> The multilayer structure enhances the mechanical stability. </LI> <LI> The multilayer membrane demonstrates a high water flux. </LI> <LI> The multilayer membrane shows high rejection rate for organic dyes. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Photograph and cross-section SEM image of GO@nylon 6 multilayer nanofiltration membrane, the inset shows the water contact angle.</P> <P>[DISPLAY OMISSION]</P>

Molecular Cloning of Two Genes Encoding Cinnamate 4-Hydroxylase (C4H) from Oilseed Rape (Brassica napus)

Chen, An-He,Chai, You-Rong,Li, Jia-Na,Chen, Li Korean Society for Biochemistry and Molecular Biol 2007 Journal of biochemistry and molecular biology Vol.40 No.2

Cinnamate 4-hydroxylase (C4H) is a key enzyme of phenylpropanoid pathway, which synthesizes numerous secondary metabolites to participate in development and adaption. Two C4H isoforms, the 2192-bp BnC4H-1 and 2108-bp BnC4H-2, were cloned from oilseed rape (Brassica napus). They both have two introns and a 1518-bp open reading frame encoding a 505-amino-acid polypeptide. BnC4H-1 is 57.73 kDa with an isoelectric point of 9.11, while 57.75 kDa and 9.13 for BnC4H-2. They share only 80.6% identities on nucleotide level but 96.6% identities and 98.4% positives on protein level. Showing highest homologies to Arabidopsis thaliana C4H, they possess a conserved p450 domain and all P450-featured motifs, and are identical to typical C4Hs at substrate-recognition sites and active site residues. They are most probably associated with endoplasmic reticulum by one or both of the N- and C-terminal transmembrane helices. Phosphorylation may be a necessary post-translational modification. Their secondary structures are dominated by alpha helices and random coils. Most helices locate in the central region, while extended strands mainly distribute before and after this region. Southern blot indicated about 9 or more C4H paralogs in B. napus. In hypocotyl, cotyledon, stem, flower, bud, young- and middle-stage seed, they are co-dominantly expressed. In root and old seed, BnC4H-2 is dominant over BnC4H-1, with a reverse trend in leaf and pericarp. Paralogous C4H numbers in Brassicaceae genomes and possible roles of conserved motifs in 5' UTR and the 2nd intron are discussed.

Effect of Laser Power on Tensile Performance of TA15 Laser-Welded Lock Bottom Joint

Na Qi,Xiaohong Zhan,Shuai Chen,Dan Chen,Shi He 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.11

Taking TA15 titanium alloy as the research object, laser welding experiments of are performed on the lock-bottom joints,and the microstructure and tensile performance of the joints are analyzed. The laser welding speed is constant and the laserpower is 1000 w, 1300 kw, 1600 kw respectively. The bottom weld width and the width of high temperature heat-affectedzone (HT-HAZ) increase significantly as laser power increase. The microstructure of the heat-affected zone (HAZ) is relativelycomplicated, mainly composed of secondary α, acicular α structure and β. The microstructure at the weld metal iscomprised of the martensite α′ and acicular α. The tensile strength, fracture morphology and chemical composition of thewelded joint are studied by tensile test, scanning electron microscope (SEM) and energy dispersive spectrometer (EDS)analysis techniques. The results show that all the specimens fractured near the heat-affected zone, and the fracture is a ductilefracture in the shape of a dimple. The tensile strength of welded joint decreases with the increase of laser power. Whenthe laser power is 1.0 kw, 1.3 kw and 1.6 kw, the tensile strength is 723 MPa, 705 MPa and 695 MPa respectively, which is64.55%, 62.95% and 62.05% of the base material strength. EDS results show that Mo and V elements are the strengtheningelements, while the burning loss of Mo and V reduce the strength of the joint.

Isolation and Characterization of Bacillus sp. Producing Broad-Spectrum Antibiotics Against Human and Plant Pathogenic Fungi

( Na Chen ),( Min Jin ),( Hong Mei Qu ),( Zhi Qiang Chen ),( Zhao Li Chen ),( Zhi Gang Qiu ),( Xin Wei Wang ),( Jun Wen Li ) 한국미생물 · 생명공학회 2012 Journal of microbiology and biotechnology Vol.22 No.2

A strain of bacterium producing antifungal antibiotic was isolated and identification of the strain was attempted. We could identify the bacterium as being a Bacillus sp., based on morphological observation, physiological characteristics, and 16S rDNA sequence analysis, thus leading us to designate the strain as Bacillus sp. AH-E-1. The strain showed potent antibiotic activity against phytopathogenic and human pathogenic fungi by inducing mycelial distortion and swelling and inhibiting spore germination. The antibiotic metabolite produced by the strain demonstrated excellent thermal and pH (2-11) stability, but was labile to autoclaving. From these results, we could find a broader antifungal activity of Bacillus genus. Isolation and characterization of the active agent produced by the strain are under progress.

Over-expression of GmHAL3 modulates salt stresses tolerance in transgenic arabidopsis

Na Guo,Ming-xia Wang,Chen-chen Xue,Dong Xue,Jin-yan Xu,Hai-tang Wang,Jun-Yi Gai,Han Xing,Jin-ming Zhao;Han Xing 한국식물학회 2016 Journal of Plant Biology Vol.59 No.5

The halotolerance protein HAL3, also known as SIS2, is a yeast protein that regulates the cell cycle and tolerance to salt stress through inhibition of the Ppz1 type 1 protein phosphatase. Although the roles of HAL3 have been demonstrated during the growth, development, and stress adaptation of Arabidopsis thaliana and Nicotiana tabacum, the function of HAL3 in other plant species, including soybean (Glycine max), has not been elucidated. In this study, GmHAL3a and GmHAL3b were isolated from Glycine max, and their roles were analyzed. GmHAL3a and GmHAL3b transcripts were detected in the roots, stems, leaves and seeds, with higher levels in the roots, and were induced by sodium chloride (NaCl), lithium chloride (LiCl), sorbitol, cold and ABA treatment. Overexpression of GmHAL3a or GmHAL3b in Arabidopsis accelerated the onset of flowering and resulted in more vigorous seed germination and increased tolerance to NaCl, LiCl, and sorbitol stress in seedlings, compared with wild type (WT) and empty vector control (VC) plants. Transgenic Arabidopsis plants accumulated proline and eliminated superoxide radical (O2 −) in response to the stress. In addition, transcription levels of the stress-related genes RD22 and P5CS1 were substantially higher in transgenic Arabidopsis than in WT and VC plants. Taken together, the data indicate that GmHAL functions as a positive regulator of the response to salt, lithium cations and sorbitol stress.

Long-term continuously monocropped peanut significantly disturbed the balance of soil fungal communities

Chen Mingna,Zhang Jiancheng,Liu Hu,Wang Mian,Pan LiJuan,Chen Na,Wang Tong,Jing Yu,Chi Xiaoyuan,Du Binghai 한국미생물학회 2020 The journal of microbiology Vol.58 No.7

Balancing soil microbial diversity and abundance is critical to sustaining soil health, and understanding the dynamics of soil microbes in a monocropping system can help determine how continuous monocropping practices induce soil sickness mediated by microorganisms. This study used previously constructed gradient continuous monocropping plots and four varieties with different monocropping responses were investigated. The feedback responses of their soil fungal communities to short-term and long-term continuous monocropping were tracked using high-throughput sequencing techniques. The analyses indicated that soil samples from 1 and 2 year monocropped plots were grouped into one class, and samples from the 11 and 12 year plots were grouped into another, regardless of variety. At the species level, the F. solani, Fusarium oxysporum, Neocosmospora striata, Acrophialophora levis, Aspergillus niger, Aspergillus corrugatus, Thielavia hyrcaniae, Emericellopsis minima, and Scedosporium aurantiacum taxa showed significantly increased abundances in the long-term monocropping libraries compared to the short-term cropping libraries. In contrast, Talaromyces flavus, Talaromyces purpureogenus, Mortierella alpina, Paranamyces uniporus, and Volutella citrinella decreased in the long-term monocropping libraries compared to the shortterm libraries. This study, combined with our previous study, showed that fungal community structure was significantly affected by the length of the monocropping period, but peanut variety and growth stages were less important. The increase in pathogen abundances and the decrease in beneficial fungi abundances seem to be the main cause for the yield decline and poor growth of long-term monocultured peanut. Simplification of fungal community diversity could also contribute to peanut soil sickness under long-term monocropping. Additionally, the different responses of peanut varieties to monocropping may be related to variations in their microbial community structure.

Absence of EZH2 Gene Mutation in Chronic Myeloid Leukemia Patients in Blast Crisis

Chen, Hao-Yue,Yao, Hong,Wu, Ling-Yu,Liu, Can-Jun,Zhu, Jian-Qin,Liu, Chun-Hua,Wang, Wei,Dong, Sha-Sha,Ping, Na-Na,Chen, Su-Ning,Sun, Miao Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.5

Characterization of proteolysis in muscle tissues of sea cucumber Stichopus japonicus

Chen-Chen Zhao,Yang Yang,Hai-tao Wu,Zhi-Mo Zhu,Yue Tang,Cui-Ping Yu,Na Sun,Qiang Lv,Jia-Run Han,Ao-Ting Li,Jia-Nan Yan,Yue Cha 한국식품과학회 2016 Food Science and Biotechnology Vol.25 No.6

The proteolysis in muscle tissues of sea cucumber Stichopus japonicus (sjMTs) was characterized. The proteins from sjMTs were primarily myosin heavy chains (MHCs), paramyosin (Pm), and actin (Ac) having a molecular mass of approximately 200, 98, and 42 kDa, respectively. Based on SDS-PAGE analysis and quantification of trichloroacetic acid (TCA)-soluble peptides released, degradation of muscle proteins from sjMTs was favorable at pH 5 and 50°C. Proteolysis of MHCs was mostly inhibited by cysteine protease inhibitors, including trans-epoxysuccinyl-L-leucyl-amido (4- guanidino) butane (E-64) and antipain (AP). E-64 and AP completely inhibited the degradation of Pm and Ac, while iodoacetic acid showed a partially inhibitory effect. These results indicated that the proteolysis of sjMTs was mainly attributed to cysteine proteases. Avoidance of setting the tissues at 40–50oC and slightly acidic condition and inhibition of cysteine proteases are helpful for decreasing sea cucumber autolysis.

Fabricating Fe₃O₄ and Fe₃O₄&Fe Flower-like microspheres for Electromagnetic Wave Absorbing in C and X Bands

Na Chen,Dan Li,Xin‑Yi Wang,Zhen‑Jie Guan,Jian‑Tang Jiang,Kang‑Jun Wang 대한금속·재료학회 2022 ELECTRONIC MATERIALS LETTERS Vol.18 No.4

Magnetic composites have received increasing attention for electromagnetic wave absorption (EMA) applications. However,the practical EMA performance of the materials is severely hampered by mismatching impedance characteristics and finiteelectromagnetic attenuation capacity. Controlling the components and building the architecture fabrication is necessary tosolve these issues. Herein, a series of Fe3O4,Fe3O4&Fe and Fe microspheres with flower-like hierarchical structures wereconstructed through a solvothermal method followed by an annealed process. This hierarchical structure and the synergyeffect of dielectric dissipation and magnetic loss capacity offer Fe3O4a perfect impedance matching, providing an excellentEMA performance of an effective absorption bandwidth (EAB) of 4.0 GHz and a reflection loss (RL) of 67.9 dB. Meanwhile,the coordination of the hierarchical structures and the multiple components endow Fe3O4&Fe composites with an EAB aswide as 5.7 GHz (9.0–14.7 GHz) and a RL as strong as 78.7 dB at 1.88 mm, which covers 75% X and 45% Ku bands. Sucha remarkable lightweight and broad properties is due to the decent X band impedance matching and appropriate attenuationcapacity. Therefore, this work highlights the significant of regulating the hierarchical structure and components to enhancethe EMA performances.

Designing Co7Fe3@TiO2 Core–Shell Nanospheres for Electromagnetic Wave Absorption in S and C Bands

Na Chen,Jian‑Tang Jiang,Zhen‑Jie Guan,Shao‑Jiu Yan,Liang Zhen,Cheng‑Yan Xu 대한금속·재료학회 2020 ELECTRONIC MATERIALS LETTERS Vol.16 No.5

Ferromagnetic-dielectric nanocomposites have attracted extensive interests for its high electromagnetic wave absorption(EMA) performance due to the synergetic effects between different components. Herein, we report the design of core–shellstructured Co7Fe3@TiO2 composite particles, which are subsequently annealed in H2/Ar atmosphere to further improve itsEMA performance. The introducing of TiO2dielectric shell together with hydrogen annealing contributes greatly to theelectromagnetic properties due to the increased conductivity and enhanced ferromagnetic resonance. Excellent EMA performanceis achieved in S (2–4 GHz) and C (4–8 GHz) bands in coatings using Co7Fe3@TiO2 as absorbents. Apart from thehigh EMA efficiency, the location of EMA band can be tailored in a wide range through regulating the coating thickness. Specifically, an effective absorption band of 2.0 GHz in C band at a thickness of 2.62 mm, and an effective absorption bandof 1.7 GHz are achieved in S band at thicknesses of 4.0–5.0 mm. The excellent electromagnetic properties are ascribed tothe effective complementary between dielectric loss and ferromagnetic loss.