Food and Bioprocess Technology
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2017
·Vol. 10
·期 10
·1844-1853
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IF 2.576
Ye Youxin,Zhu Mingjin,Miao Keyan,Li Xinying,Li Defu,Mu Changdao
Antimicrobial activity is an attractive property for packaging materials which can extend the shelf life of products and provide microbial safety for consumers. The study aimed to analyze the physicochemical and antimicrobial properties of gelatin-based edible films containing trans -anethole as the active additive. Encapsulation with β-cyclodextrin was used as an effective way to introduce trans -anethole into gelatin matrix. The results showed that the trans -anethole/β-cyclodextrin inclusion complex could be evenly dispersed in the gelatin-based edible films with appropriate addition. The incorporation of trans -anethole conferred the edible films with good antimicrobial activity as expected, which increased with the content of trans -anethole increasing. Moreover, the addition of inclusion complex improved the tensile strength and surface hydrophobicity and reduced the moisture content of the edible films. It was interesting that the edible films presented great UV light barrier property and it was increased by the addition of inclusion complex. Overall, the antimicrobial gelatin-based edible films showed great potential as bioactive packaging materials to extend food shelf life.
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Scientific Reports
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2017
·Vol. 7
·期 1
·1-10
·
IF 4.259
Jia Xiaojing,Liu Ying,Han Yejun
Acetoin (3-hydroxy-2-butanone) is an important bio-based platform chemical with wide applications. In vitro enzyme catalysed synthesis exhibits great feasibility in the production of chemicals with high purity. In the present work, a synthetic pathway involving a two-step continuous reaction was constructed in vitro for acetoin production from pyruvate at improved temperature. Thermostable candidates, acetolactate synthase (coAHASL1 and coAHASL2 from Caldicellulosiruptor owensensis OL) and α-acetolactate decarboxylase (bsALDC from Bacillus subtilis IPE5-4) were cloned, heterologously expressed, and characterized. All the enzymes showed maximum activities at 65–70 °C and pH of 6.5. Enzyme kinetics analysis showed that coAHASL1 had a higher activity but lower affinity against pyruvate than that of coAHASL2. In addition, the activities of coAHASL1 and bsALDC were promoted by Mn 2+ and NADPH. The cascade enzymatic reaction was optimized by using coAHASL1 and bsALDC based on their kinetic properties. Under optimal conditions, a maximum concentration of 3.36 ± 0.26 mM acetoin was produced from 10 mM pyruvate after reaction for 24 h at 65 °C. The productivity of acetoin was 0.14 mM h −1 , and the yield was 67.80% compared with the theoretical value. The results confirmed the feasibility of synthesis of acetoin from pyruvate with a cell-free enzyme catalysed system at improved temperature.
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PubMed
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JOURNAL OF NANOPARTICLE RESEARCH
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2017
·Vol. 19
·期 7
·1-8
·
IF 2.02
Han Jishu,Sun Xiaoxia,Zhao Ruiyang,Gao Hongtao,Wang Lei
Degradation of hazardous organic dyes utilizing multifunctional catalytic materials is supposed to be an efficient and promising method. Here, homogeneous Cu-Fe 3 O 4 nanocomposites are synthesized through a facile and versatile one-pot hydrothermal method. The prepared Cu-Fe 3 O 4 possesses spherical structure with rough surface and average diameter of 230 nm. High catalytic activity and structure stability make Cu-Fe 3 O 4 nanocomposites effectively degrade rhodamine B, methylene blue, methyl orange, and congo red. The existence of magnetic Fe 3 O 4 leads the nanocomposites to separate from the solution through external magnet and reuse for cycle degradation. And during the cyclic utilization, Cu-Fe 3 O 4 nanocomposites keep high catalytic activity and, thus, could be used as an efficient degradation catalyst for the application of organic dyes.
Graphical abstract
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Nano Research
·
2016
·Vol. 9
·期 12
·3893-3902
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IF 8.893
Kang Yongqiang,Li Fumin,Li Shuni,Ji Pujun,Zeng Jinhui,Jiang Jiaxing,Chen Yu
Nanocrystals of Rh, an important member of the noble metal catalyst family, have wide applications in heterogeneous catalytic reactions. Controlling the morphology of these noble metal nanocrystals has become an effective strategy for improving their catalytic activity and durability. In this work, well-defined Rh nanodendrites with very thin triangular branches as subunits are synthesized using a facile diethylene glycol reduction method, assisted by polyethyleneimine as a complex-forming agent and surfactant. For the first time, the methanol oxidation reaction (MOR) on Rh nanocrystals with a well-defined morphology is investigated using various electrochemical techniques in an alkaline medium. Unexpectedly, the as-prepared Rh nanodendrites, with ultrathin nanosheet subunits, exhibit superior electrocatalytic activity and durability during the MOR in an alkaline medium, indicating that Rh nanocrystals with specific morphology may be highly promising alternatives to Pt electrocatalysts in the MOR in an alkaline medium.
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JOURNAL OF SOLID STATE ELECTROCHEMISTRY
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2017
·Vol. 22
·期 1
·41-49
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IF 2.316
Guo Yanyang,Yao Runrun,Wang Zimeng,Zhang Yufan,Cui Mengjing,Zhao Qiuyue,Wang Huan
Novel potential type electrochemical chiral biosensing system with unique capability of distinguishing and quantitating of tyrosine (Tyr) enantiomers by L-cysteic acid and left-handed chiral carbonaceous nanotubes (L-CCNT) modified glassy carbon electrode (L-Cys/L-CCNT/GCE) was first developed. The effect of sweep cycles of L-Cys and the kinds of L-CCNT on electrochemical chiral biosensing performance of L-Cys/L-CCNT/GCE were investigated. The electrochemical identification and quantitative determination of L- and D-tyrosine in their mixed solution were successfully achieved based on the different oxidation potential signals. The chiral structure of L-CCNT, the aromatic ring of Tyr, and also the intermolecular hydrogen bond between cysteic acid (CyA) and Tyr could possibly produce the difference in the free energy, which reflects as potential difference of L- and D-tyrosine. A good linear relationship between the potential, current, and different concentration ratios of L- and D-Tyr was obtained. Our present work realizes the simultaneous detection of Tyr enantiomers in their mixed solution based on the different potential signals, and it is of far-reaching significance in real electrochemical chiral biosensor study.
Construction of chiral recognition interface and the chiral biosensing mechanism for L-Tyr and D-Tyr
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2017
·Vol. 28
·期 20
·15004-15008
·
IF 2.019
Cao Renping,Liu Xing,Bai Kailei,Chen Ting,Luo Zhiyang,Zheng Guotai,Ao Hui,Fu Jingwei
RMgPO 4 :Mn 2+ (R = Li, Na, and K) phosphors are synthesized by a solid-state reaction method in air. The crystal structures and luminescence properties are investigated. A broad emission band peaking at 638 nm of RMgPO 4 :Mn 2+ (R = Li and Na) phosphors with excitation 408 nm is observed in the range of 550–800 nm owing to the 4 T 1 (G) → 6 A 1 transition of the Mn 2+ ion. KMgPO 4 :Mn 2+ phosphor with excitation 416 nm shows a broad emission band peaking at 658 nm in the range of 550–800 nm owing to the 4 T 1 (G) → 6 A 1 transition of the Mn 2+ ion. The optimal Mn 2+ ion concentration in RMgPO 4 :Mn 2+ (R = Li, Na, and K) phosphors is about 5 mol%. The lifetimes of RMg 0.95 PO 4 :0.05Mn 2+ (R = Li, Na, and K) phosphors is ~6.21, 6.03, and 6.28 ms, respectively. The luminous mechanism is explained by Tanabe-Sugano diagram of Mn 2+ ion.
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JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
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2017
·Vol. 83
·期 3
·545-554
·
IF 1.575
Li Shanghong,Zhang Lei,Li Ji,Wu Ze,Yang Chunhui
Abstract Silica aerogels are utilized in the industry and scientific investigations. However, most silica aerogels are brittle, which hinders their development and application. In this paper, we reported the design and synthesis of a silica aerogel composite reinforced with silica nanowires by using two silicon sources: propyltriethoxysilane and tetraethoxysilane. The effects of varying silica nanowires contents on the properties of the silica aerogel composites were studied and compared with those of neat silica aerogel under identical conditions. The composites were obtained by mixing silica nanowires with hybrid silica sol without surface modification and dried in ambient atmosphere. The samples showed low density (0.172 g cm −3 ), high porosity (over 90%), and super hydrophobicity (the water contact angle reached 153°). The cross-linked silica aerogel composites showed excellent mechanical behavior and can be compressed by as high as 70% of their initial length before they were broken. The maximum completely recoverable compressive strain reached 50%. The elastic modulus of the optimal silica nanowires/silica aerogel composite increased by 67% (from 0.21 to 0.35 MPa) compared with that of the neat silica aerogel. The cross-linked propyltriethoxysilane and tetraethoxysilane can be used to synthesize new types of elastic silica aerogels, and the excellent performance of the silica nanowires/silica aerogels composite will enable its application in various fields. Graphical Abstract
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JOURNAL OF FLUORESCENCE
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2017
·Vol. 27
·期 4
·1421-1426
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IF 1.461
Mao Mi,Deng Chun,He Yu,Ge Yili,Song Gongwu
We developed a sensitive and selective method for detection of 4-Nitrophenol (PNP) using Ag nanoclusters (NCs) as fluorescence probe. Bovine serum albumin (BSA) was used as the template for preparing Ag NCs via wet chemistry. The fluorescence of as-prepared Ag NCs was significantly quenched in the presence of PNP, showing excellent linear relationships between the quenching degree of the fluorescence intensity and the concentrations of PNP in the range of 0.5 μM to 60 μM. The fluorescence quenching mechanism was also investigated. Furthermore, this method was applied for the recognition of PNP in environmental samples.
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PubMed
高影响因子
Journal of Pharmaceutical Investigation
·
2017
·Vol. 48
·期 3
·341-350
·
IF 0
Liu Jiang-Yan,Zhang Xiao-Xue,Huang Hao-Yan,Lee Beom-Jin,Cui Jing-Hao,Cao Qing-Ri
The aim of this study was to develop esomeprazole magnesium (EMZ-Mg) enteric-coated pellets and pellet-based tablets, as well as to investigate the effects of pellet size and compression method on acid tolerance, content uniformity, compressibility, and stability of preparations. This study used two types of pellet cores, namely, microcrystalline cellulose (MCC) core with a particle size of 150–300 μm and sucrose core with a particle size of 600–700 μm. Enteric-coated pellets, which consisted of a drug-free core, a drug layer, a sub-coating layer (hydroxypropyl methylcellulose, 6 cps), and an enteric-coating layer (Eudragit ® L30D-55), were prepared by using a bottom-spray fluidized bed-coating technique. Pellet-based tablets were prepared by using a direct compression method or a wet granulation method. The acid tolerances of the two types of enteric-coated pellets (MCC and sucrose cores) reached up to 98% in simulated gastric fluid (pH 1.0) within 2 h, and the dissolution rates in simulated intestinal fluid (pH 6.8) reached up to 85% of the labeled amount within 15 min. When compressed into tablets, the pellets based on MCC core (smaller particle size) displayed a significantly higher acid tolerance (up to 92%) compared with the pellets based on sucrose core (larger particle size). In addition, the MCC core-based tablets (F8), especially those prepared by using a granulation method, showed higher drug content uniformity and compressibility than the sucrose core-based tablets (F10), and no lamination phenomenon was observed during compression. The crystallinity of EMZ-Mg was altered during drug layering process, and some physicochemical interactions were observed between the drug and excipients. Moreover, the two types of enteric-coated pellets showed a relatively high stability after storage under high temperature and strong light. However, they showed poor stability under high humidity, resulting in remarkable degradation of active compound. The EMZ-Mg enteric-coated pellets and pellet-based tablets were successfully developed, and reduction in pellet size and wet granulation reduced the differences in content uniformity and better protected the pellet coating from damages during compression.
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MICROCHIMICA ACTA
·
2017
·Vol. 184
·期 7
·2291-2298
·
IF 4.58
Wu Huifang,Jiang Jiahui,Gu Xiaoting,Tong Changlun
Nitrogen and sulfur co-doped carbon quantum dots (N,S-CQDs) with a high quantum yield (69%) and excellent photoluminescent properties were synthesized via a facile hydrothermal method using citric acid and cysteine as precursors. The cytotoxicity of N,S-CQDs was evaluated through the MTT assays using HepG2 cells as the target. The cell viability is still >95% after a 24 h incubation with particles in a concentration of up to 300 μg·mL −1 , thereby indicating low cytotoxicity and excellent biocompatibility of N,S-CQDs. The emission spectra of the N,S-CQDs are nearly independent of the excitation wavelengths in the range from 280 to 380 nm and have the strongest fluorescence emission centered at 415 nm. Co-doping with N and S promotes the electron-transfer rate and coordination interaction between N,S-CQDs and Fe(III) ions which acts as a quencher of fluorescence. Fluorescence can be recovered, however, by addition of L-Cys. Hence, the N,S-CQDs act as a highly sensitive and selective “turn-off-on” probe for the determination of Fe(III) or Cys. The limits of detection are 14 nM for Fe(III) and 0.54 μM for Cys. The interferences by 17 common metal ions and heavy metal ions, 12 other quenchers and 16 amino acids were investigated and found to be tolerable. The probe was successfully applied for cellular imaging of Fe(III) in HepG2 cells by using fluorescence microscopy.
Nitrogen and sulfur co-doped carbon quantum dots (N,S-CQDs) with a high quantum yield of 69% were prepared through a facile one-step hydrothermal method. They are shown to be a highly sensitive and selective fluorescent “turn-off-on” probe for Fe(III) ions and cysteine.
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JOURNAL OF NANOPARTICLE RESEARCH
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2017
·Vol. 19
·期 2
·1-8
·
IF 2.02
Qin Ji-Hua,Liu Zhao-Qing,Li Nan,Chen Yi-Bo,Wang Dong-Yao
The nanofluid as a pivotal role in heat transfer system has attracted more and more attention. Herein, the stearic acid-modified CuS (SA-CuS) nanoparticles with a uniform diameter of 60 nm were synthesized successfully by a facile two-phase approach. Accordingly, the CuS-oil nanofluids, with SA-CuS concentrations ranging from 0.01 to 0.04 vol%, were prepared by a one-step method in the heat transfer oil. These CuS-oil nanofluids exhibit good stability and considerable enhanced thermal conductivity. The improvement is even up to 20.5% with a volume fraction of 0.04 vol% at 30 °C. Furthermore, the effect of volume fraction and temperature on the viscosity of the nanofluids was also systematically investigated.
Graphical Abstract
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JOURNAL OF MATERIALS SCIENCE
·
2017
·Vol. 53
·期 2
·1568-1579
·
IF 2.599
Liang Miao,Zhang Guo,Feng Yajie,Li Ruili,Hou Pei,Zhang Junsong,Wang Jianmin
Facile and robust immobilization of metal nanoparticles onto porous supporting matrix is an important issue in heterogeneous catalysis. This study reports a facile procedure for the synthesis and immobilization of small catalytic active silver nanoparticles (AgNPs) on cellulose paper (CP), which possesses interconnected fibrous structure and can be employed as cost-effective supports. Amino groups were first introduced to CP, through a silane coupling technique, to provide stable anchoring centers for silver ions. Small-sized AgNPs without aggregation were facilely synthesized and stably immobilized onto the fiber surface of CP followed by NaBH 4 reduction. The as-prepared AgNPs incorporating composites exhibited excellent catalytic activity for the reduction of 4-nitrophenol. The rate constant of the catalytic reaction was calculated to be 1.46 × 10 −2 s −1 . More importantly, these amino-modified paper-based composite catalysts can be easily recovered and reused for at least six cycles due to their enhanced mechanical and catalytic stability.
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