JOURNAL OF APPLIED POLYMER SCIENCE
·
2013
·Vol. 130
·期 5
·3600-3610
·
IF 1.395
Mengzhu Liu,Zhiqiang Cheng,Yi Jin,Xin Ru,Dawei Ding,Junfeng Li
Poly( l -lactide- co -ε-caprolactone-diOH) (PCLA) with (ABA) n type is synthesized using poly(lactic acid) (PLA) and poly(ε-caprolactone) di-OH (PCL-diOH) via chain extending method. FT-IR, 1 H-NMR, and GPC data demonstrate that PLA and PCL-diOH have reacted completely. The product is electrospun into ultrafine fibers subsequently. The optimum electrospinning parameters obtain from an orthogonal experiment are a solvent ratio (DMF/DCM) of 5/5, a polymer concentration of 28 wt %, a collector distance of 20 cm and a voltage of 18 kV. As a result, the average diameter of fibers is 0.77 µm and the uniformity is above 80%. Via range analysis, it is found that the order of the influence on diameter is solvent ratio, applied voltage, collector distance, and polymer concentration, successively. Single effect of the four governing factors on diameter and morphology is also experimentally investigated. This may provide clues for obtaining fibers with various structures by controlling the parameters. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3600–3610, 2013
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NEW JOURNAL OF CHEMISTRY
·
2015
·Vol. 39
·期 5
·4154-4161
·
IF 3.086
Lei Chen,Bing Yan
A series of novel multi-component photofunctional hybrid materials were assembled using lanthanide (Ln) polyoxometalates (Na9LnW10O36·32H2O, for LnW10, Ln = europium (Eu), terbium (Tb), samarium (Sm) or dysprosium (Dy)), ionic liquids (IMCl) and functionalized zeolite A/L through an inside–outside double modification path. Firstly, the zeolite A/L was functionalized with Ln complexes (Eu-thenoyltrifluoroacetone (TTA) or Tb-trifluoroacetylacetone (TAA)) using the ion-exchange treatment and “ships in a bottle” dispersion. Then, 1-methyl-3-(trimethoxysilyl)propyl chloride (IM+Cl−) was covalently grafted onto the functionalized zeolite A/L and linked to Ln polyoxometalates as a double linker. These hybrids have two luminescence centers, one is Ln complexes, and the other is Ln polyoxometalates. By adjusting the different components of the hybrids, the luminescent tuning and integration of various colors (white, warm-white, green and red light) can be realized. These results can be expected to have potential application in appropriate fields.
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Nanoscale
·
2016
·Vol. 8
·期 18
·9764-9770
·
IF 7.76
Tengfei Long,Yanjia Guo,Min Lin,Mengke Yuan,Zhongde Liu,Chengzhi Huang
Despite a significant surge in the number of investigations into both optically active Au and Ag nanostructures, there is currently only limited knowledge about optically active Cu nanoclusters (CuNCs) and their potential applications. Here, we have succeeded in preparing a pair of optically active red-emitting CuNCs on the basis of complexation and redox reaction between copper(II) and penicillamine (Pen) enantiomers, in which Pen serves as both a reducing agent and a stabilizing ligand. Significantly, the CuNCs feature unique aggregation induced emission (AIE) characteristics and therefore can serve as pH stimuli-responsive functional materials. Impressively, the ligand chirality plays a dramatic role for the creation of brightly emissive CuNCs, attributed to the conformation of racemic Pen being unfavorable for the electrostatic interaction, and thus suppressing the formation of cluster aggregates. In addition, the clusters display potential toward cytoplasmic staining and labelling due to the high photoluminescence (PL) quantum yields (QYs) and remarkable cellular uptake, in spite that no chirality-dependent effects in autophagy and subcellular localization are observed in the application of chiral cluster enantiomer-based cell imaging.
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高影响因子
JOURNAL OF FOOD SCIENCE
·
2016
·Vol. 81
·期 6
·C1370
·
IF 1.649
Chen Jiang,Yuyun Lu,Zhuo Li,Cunzhi Li,Rian Yan
en A series of novel l -ascorbyl fatty acid esters were synthesized by catalization of Novozym ® 435 under ultrasonic irradiation and characterized by infrared spectroscopy, electrospray ionization mass spectra, and nuclear magnetic resonance. Their properties especially antioxidant activity and stability were investigated. The results showed that the reducing power, the scavenging activity of hydroxyl radical and 2,2-diphenyl-1-picrylhydrazyl radical were decreased with the increase of the number of carbon atoms in fatty acid. The hydroxyl radical scavenging activity and reducing power of l -ascorbyl saturated fatty acid esters were better than that of tert-butylhydroquinone. The induction period in lipid oxidation of l -ascorbyl saturated fatty acid esters and tert-butylhydroquinone were longer than that of l -ascorbyl unsaturated fatty acid esters and l -ascorbic acid both in soybean oil and lard. Besides, the l -ascorbyl fatty acid esters showed different stabilities in different conditions by comparing with l -ascorbic acid, and the l -ascorbyl saturated fatty acid esters were more stable than l -ascorbyl unsaturated fatty acid esters in ethanol solution. Practical Application pt l -Ascorbyl fatty acid esters, with good solubility in hydrophobic conditions, showed similar or even better antioxidant activity and stability than l -ascorbic acid. They could be used to replace the traditional antioxidants in food and cosmetic industry.
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TALANTA
·
2016
·
IF 4.035
Yi Zhang,Peipei Cui,Feng Zhang,Xiaoting Feng,Yaling Wang,Yongzhen Yang,Xuguang Liu
Fluorescent nitrogen-doped carbon dots (NCDs) were synthesized by a facile, and low-cost one-step hydrothermal strategy using citric acid as carbon source and ammonia solution as nitrogen source for the first time. The obtained NCDs show stable blue fluorescence with a high quantum yield of 35.4%, along with the fluorescence lifetime of ca. 6.75 ns. Most importantly, Hg 2+ can completely quench the fluorescence of NCDs as a result of the formation of a non-fluorescent stable NCDs–Hg 2+ complex. Static fluorescence quenching towards Hg 2+ is proved by the Stern–Volmer equation, ultraviolet–visible absorption spectra, temperature dependent quenching and fluorescence lifetime measurements. Subsequently, the fluorescence of the NCDs–Hg 2+ system is completely recovered with the addition L-cysteine (L-Cys) owing to the dissociation of NCDs–Hg 2+ complex to form a more stable Hg 2+ -L-Cys complex by Hg 2+ –S bonding. Therefore, such NCDs can be used as an effective fluorescent “turn-off” probe for rapid, rather highly selective and sensitive detection of Hg 2+ , with a limit of detection (LOD) as low as 1.48 nM and a linear detection range of 0–10 μM. Interestingly, NCDs–Hg 2+ system can be conveniently employed as a fluorescent “turn-on” sensor for highly selective and sensitive detection of L-Cys with a low LOD of 0.79 nM and a wide linear detection range of 0–50 μM. Further, the sensitivity of NCDs to Hg 2+ is preserved in tap water with a LOD of 1.65 nM and a linear detection range of 0–10 μM.
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高影响因子
MOLECULES
·
2016
·Vol. 21
·期 3
·360
·
IF 2.465
Xin Wang,Jianguo Cao,Yuhuan Wu,Quanxi Wang,Jianbo Xiao
Marchantia polymorphaL. is a representative bryophyte used as a traditional Chinese medicinal herb for scald and pneumonia. The phytochemicals inM. polymorphaL. are terpenoids and flavonoids, among which especially the flavonoids show significant human health benefits. Many researches on the gametophyte ofM. polymorphaL.have been reported. However, as the reproductive organ ofM. polymorphaL., the bioactivity and flavonoids profile of the archegoniophore have not been reported, so in this work the flavonoid profiles, antioxidant and acetylcholinesterase inhibition activities of the extracts from the archegoniophore and gametophyte ofM. polymorphaL.were compared by radical scavenging assay methods (DPPH, ABTS, O2−), reducing power assay, acetylcholinesterase inhibition assay and LC-MS analysis. The results showed that the total flavonoids content in the archegoniophore was about 10-time higher than that of the gametophyte. Differences between the archegoniophore and gametophyte ofM. polymorphaL. were observed by LC-MS analysis. The archegoniophore extracts showed stronger bio-activities than those of the gametophyte. The archegoniophore extract showed a significant acetylcholinesterase inhibition, while the gametophyte extract hardly inhibited it.Keywords:Marchantia polymorphaL.;flavonoids;antioxidant potential;archegoniophore;gametophyte;acetylcholinesterase inhibition
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高影响因子
TETRAHEDRON
·
2016
·
IF 2.645
Yuliang Jiang,Ronghua Shen,Guo Wei,Yixiang Cheng,Bingxiang Wang
This paper developed a new fluorescent rhodamine-based derivatives (RAD) probe for highly sensitive and selective detection of Cu 2+ and L-Methionine (L-Met). The detection limits can reach as low as 12 nM for Cu 2+ and 5 nM for L-Met, In addition, the RAD probe can be further applied to cell imaging owing to its photostability and low cytotoxicity.
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RSC Advances
·
2016
·Vol. 6
·期 36
·30320-30329
·
IF 3.289
Xuefei Leng,Zhiyong Wei,Yufei Bian,Yingying Ren,Yurong Wang,Qinyi Wang,Yang Li
Three series of narrowly dispersed comb-like graft poly(L-lactide) (PLLA) with controlled graft length and graft density have been facilely synthesized and characterized. The structural information was determined by means of 1H NMR, GPC, and viscometry, demonstrating the well-defined grafted structure. The effects of grafting parameters on rheological properties, thermal and crystallization behaviors were investigated systematically to illustrate the structure–property relationships. By the analysis of the rheological behavior, the increase of graft length and graft density can both lead to an elevated value of zero-viscosity (η0), enhanced complex modulus (G*) and increased complex viscosity (η*). Comparatively, graft density contributes more to the improvement of rheological properties than graft length does. For thermal properties, DSC results show that the glass transition temperature (Tg), the melting temperature (Tm) and the crystallization enthalpy (ΔHm) of graft PLLA increase with the chain length and decrease with the graft density. Furthermore, spherulite morphologies and growth rates were studied by polarized microscopy (POM), and the observation revealed a remarkable improvement of radius growth rate of the spherulites (G) when graft density increased. The results indicate that G depends more on the molecular weight of each arm (Mn,arm) than the total Mn.
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RSC Advances
·
2017
·Vol. 7
·期 29
·17711-17719
·
IF 3.108
Yingling Miao,Ruirui Yang,David Y. B. Deng,Li-Ming Zhang
Excellent biocompatibility and bioactivity are necessary requirements for a scaffold for nerve repair and regeneration. Natural plant protein zein was chosen as the primary material and poly(L-lysine), which is composed of common amino acids in the human body, was used to modify it. Poly(L-lysine) modified zein (ZPLL) with different PLL contents of 1.46%, 3.57%, and 6.18% was synthesized and nanofibrous membranes were prepared by electrospinning. The hydrophilicity of the membranes improved with an increase of PLL content. The biodegradability of the membranes was proved by in vitro experiments. Compared with pure zein membranes, ZPLL membranes can efficiently improve cell viability, adhesion, proliferation, and differentiation of neural stem cells (NSCs) and the effect of PLL content was further investigated. The results show that when the PLL content was 3.57%, cell adhesion and proliferation proved to be the best and most differentiated toward mature neurons with extensive neurite formation and astrocytes rather than oligodendrocytes. The ZPLL was made into nerve conduits for future study and they may be a promising biomaterial for nerve repair and regeneration.
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TALANTA
·
2016
·
IF 4.035
Jie Tang,Peng Wu,Xiandeng Hou,Kailai Xu
A facile yet sensitive and selective method was proposed for Hg 2+ detection based on N-acetyl-L-cysteine(NAC)-induced colorimetric response of AuNPs. The proposed method can be easily performed by introducing the premixing of NAC and Hg 2+ into as-prepared citrate-capped AuNPs solution. A combination of experimental and theoretical studies was applied to illustrate the mechanism of this AuNPs colorimetric system. The strong interaction of NAC and AuNPs through Au–S bond could lead to the aggregation of AuNPs, but the formation of NAC-Hg-NAC complex decreased the affinity between NAC and AuNPs and resulted in an anti-aggregation effect. Therefore, the color of the AuNPs solution would progress from purple to red with the increase of Hg 2+ concentration. The proposed method had a high sensitivity with a limit of detection of 9.9 nM. Coexistent metal ions , including Cd 2+ , Mn 2+ , Al 3+ , Ag + , K + , Mg 2+ , Ca 2+ , Cr 3+ , Cu 2+ , Fe 3+ , Pb 2+ , Ni 2+ and Zn 2+ , did not interfere with the detection of Hg 2+ . This method can be used to monitor Hg 2+ in tap water.
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Food & Function
·
2016
·Vol. 7
·期 6
·2886-2897
·
IF 2.686
Chun Chen,Bin Zhang,Xiong Fu,Rui Hai Liu
A novel polysaccharide (MFP3P) was isolated from Murus alba L. through the hot water extraction method followed by chromatographic purification. The chemical structure of MFP3P was elucidated by acid hydrolysis, Smith degradation and methylation analysis, along with FT-IR, GC-MS, 1H and 13C NMR spectroscopy. Its morphological properties were further characterized by SEM and AFM. The selenide of the polysaccharide (MFP3P-Se) was obtained by the Na2SeO3/BaCl2 method. The antioxidant properties showed that MFP3P-Se exhibited higher peroxy radical-scavenging capacity than MFP3P in vitro. Moreover, MFP3P-Se had more significant hypoglycemic effects than MFP3P through promoting pancreatic cell proliferation and increasing glucose metabolism and insulin secretion.
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SCIENCE OF THE TOTAL ENVIRONMENT
·
2016
·
IF 3.976
Y.H. Zhao,X. Jia,W.K. Wang,T. Liu,S.P. Huang,M.Y. Yang
Plant secondary metabolites play a pivotal role in growth regulation, antioxidant activity, pigment development, and other processes. As the global climate changes, increasing atmospheric temperatures and contamination of soil by heavy metals co-occur in natural ecosystems, which alters the pH of rhizosphere soil and influences the bioavailability and mobility of metals. Elevated temperatures in combination with heavy metals are expected to affect plant secondary metabolites, but this issue has not been extensively examined. Here, we investigated secondary metabolites in Robinia pseudoacacia seedlings exposed to elevated temperatures using a passive warming device in combination with Cd- and Pb-contaminated soils. Heavy metals significantly stimulated the accumulation of saponins, phenolic compounds , and flavonoids in leaves and stems; alkaloid compounds increased in leaves and decreased in stems, and condensed tannins fluctuated. Elevated temperatures, alone and in combination with Cd and Pb, caused increases in secondary metabolites in the plant tissues. Phenolic compounds showed the greatest changes among the secondary metabolites and significant interactive effects of temperature and metals were observed. These results suggest that slightly elevated temperature could enhance protective and defense mechanisms of Robinia pseudoacacia seedlings exposed to heavy metals by stimulating the production of secondary metabolites.
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